Dr. Corinna Zygourakis is an Assistant Professor in the Department of Neurosurgery at Stanford University School of Medicine and a board-certified neurological surgeon who specializes in comprehensive surgical care of the adult spine, focusing on the treatment of complex spinal disorders, including spinal deformity, revision surgery, and spinal tumors. Dr. Zygourakis employs the latest minimally invasive, motion-sparing, and robotic surgical techniques to achieve the best outcomes for her patients. Her philosophy is to take care of patients with respect and compassion, as she would want her own family treated.

Dr. Zygourakis trained at the Johns Hopkins Hospital for her combined neurosurgery and orthopedic surgery complex spine fellowship, where she performed the first surgery internationally with the Globus Excelsius spinal robot. She completed her residency at the top-ranked neurosurgical program at the University of California, San Francisco, and obtained her M.D. degree cum laude from Harvard Medical School. She received her B.S. degree with honors from the California Institute of Technology, where she received a full merit scholarship and the Mabel Beckman Commencement Prize to the Top Graduating Woman in her class. She has received numerous awards including “Top 20 Under 40 Spine Surgeons” (SpineLine, North American Spine Society) and the Paul and Daisy National Fellowship for New Americans.

Committed to serving and advocating for spine patients through her clinical, education, and research efforts, Dr. Zygourakis has published more than eighty scientific articles and book chapters on healthcare costs, quality of neurosurgical care, and spine surgery. Her current research efforts include developing and leading the first randomized clinical trial using the Apple Watch to objectively track patient movement and function before and after spine surgery, as well as multiple studies investigating the impact of race, gender, and socioeconomic status on spinal surgery access and outcomes.

Clinical Focus

  • Neurosurgery
  • Spinal Deformity Surgery
  • Spine Tumor Surgery
  • Minimally Invasive Spine Surgery
  • Robotic Spine Surgery
  • Spinal Cord Injury

Academic Appointments

Honors & Awards

  • Byers Center for Biodesign Faculty Fellowship, Stanford University (2019-2020)
  • Top 20 Under 40 Spine Surgeons, SpineLine, North American Spine Society (2019)
  • High Impact Manuscript Award, Neurosurgery (2017)
  • Best Senior Resident Clinical Research Presentation, Resident Research Day, University of California, San Francisco (2016)
  • Excellence and Innovation Award in Graduate Medical Education, University of California, San Francisco (2016)
  • Sustainability Award from UCSF Chancellor for Project on OR Waste, University of California, San Francisco (2016)
  • UCSF Health "Great Save Award" from CEO for OR Surgical Cost Reduction Project, University of California, San Francisco (2016)
  • CTSI Catalyst Award, Development of Doctor Mobile App that Decreases Costs, University of California, San Francisco (2015)
  • Naffziger Award for Outstanding Neurosurgical Resident, University of California, San Francisco (2015)
  • UCSF Center for Healthcare Value Research Fellowship, University of California, San Francisco (2015)
  • Caring Wisely Grant, OR SCORE (OR Surgical Cost Reduction Project), University of California, San Francisco (2014)
  • Cum Laude, Harvard Medical School (2011)
  • Seidman Prize for Outstanding Senior HST Medical Student Thesis, Harvard Medical School (2011)
  • Howard Hughes Medical Institute Research Fellowship for Medical Students, Howard Hughes Medical Institute (2008-2009)
  • Paul and Daisy Soros National Fellowship for New Americans, Paul and Daisy Soros Foundation (2006-2008)
  • Mabel Beckman Award, Caltech Commencement Prize to Top Graduating Woman, California Institute of Technology (2006)
  • Jack E. Froehlich Award, Caltech Academic Prize to Top Junior, California Institute of Technology (2005)
  • Axline and Lingle Awards, Caltech Full-Tuition Merit Scholarships, California Institute of Technology (2002-2006)
  • Neuroscience Research Prize, American Academy of Neurology & Child Neurology Society (2002)
  • USA Today All-USA High School Academic First Team, USA Today (2002)
  • United States Presidential Scholar, U.S. Presidential Scholars Program (2002)

Professional Education

  • Board Certification: American Board of Neurological Surgery, Neurosurgery (2021)
  • Fellowship: Johns Hopkins Neurosurgery Spine Fellowship (2018) MD
  • Residency: UCSF Neurological Surgery Residency (2017) CA
  • Medical Education: Harvard Medical School (2011) MA
  • Fellowship, Johns Hopkins Hospital, Complex Spine Fellowship, Depts of Neurosurgery & Orthopedic Surgery (2018)
  • Residency, University of California, San Francisco, Neurological Surgery (2017)
  • M.D., Harvard Medical School, Massachusetts Institute of Technology, Health Sciences and Technology Joint Program, Neuroscience Honors Thesis *Cum laude (2011)
  • Study Abroad, Cambridge University, Physiology (2005)
  • B.S., California Institute of Technology, Biology, English Literature *with honors (2006)

Current Research and Scholarly Interests

My goal is to translate research into real-world action and decision-making so that my work can impact patients and the institutions in which they receive care. With a research focus on healthcare cost and quality of care, I approach neurosurgery in a unique way—one that applies business operations, economics, and healthcare delivery principles to our field. I have pursued formal LEAN business training, and believe in the importance of working together with other departments and administrators, as well as physicians and surgeons on the hospital and national level, to effect change. During my residency, I developed and led a multi-departmental prospective study at UCSF called OR SCORE (OR Surgical Cost Reduction Project) that brought together surgeons from the neurosurgery, orthopedics and ENT departments with nurses and administrators. OR SCORE successfully reduced surgical supply costs by nearly one million dollars in its first year by providing >60 surgeons with price transparency scorecards. This work led to a first-author publication in JAMA Surgery, but more importantly, set the foundation for further quality improvement and cost reduction efforts across the UCSF hospital system.

A volunteer neurosurgical mission trip to Guadalajara, Mexico, where limited resources create an OR environment that is strikingly more frugal than the U.S., inspired me to lead another project aimed at quantifying and reducing operating room waste at UCSF. I have also conducted research looking at the safety and outcomes of overlapping surgery, as well as several projects to define the factors underlying variation in cost for neurosurgical care using UCSF’s hospital data and national databases like the National Inpatient Sample, Vizient (formerly known as University Health Consortium), and Medicare.

As a clinical fellow at Johns Hopkins, I continued and expanded these research efforts. I designed and implemented an Enhanced Recovery after Surgery (ERAS) protocol at the Johns Hopkins Bayview hospital. This protocol standardized care for our spine patients, emphasizing pre-operative rehabilitation, psychiatric and nutritional assessments, and smoking cessation, as well as intra- and post-operative multi-modal pain therapy, early mobilization, and standardized antibiotic and bowel regimens. I also collaborated with engineers in the Johns Hopkins Carnegie Center for Surgical Innovation to develop better algorithms for intra-operative CT imaging, and provided assistance with operations to a basic science study looking at the role of cerebrospinal fluid drainage and duraplasty in a porcine model of spinal cord injury.

At Stanford, I am building a research group focused on: (1) perfecting paradigms for delivery of high-end technology in spinal care, including robotics and navigation, (2) implementing cost and quality strategies in large healthcare systems, and (3) computational analysis of big-data to effect real-time risk stratification and decision making in spine surgery. I'm excited to collaborate with my peers across surgical and medical departments, as well as business and engineering colleagues.

Clinical Trials

  • Improving Spine Surgical Care With Real-Time Objective Patient Tracking Using the Apple Watch Not Recruiting

    One of the primary goals of spine surgery is to reduce pain and increase mobility to improve patients' quality of life. Currently, there is no established method for surgeons to objectively track their patients' mobilization postoperatively. This study is the first prospective trial utilizing the Apple Watch to objectively track patients before and after elective spine surgery. The investigators hypothesize that the ability of patients to track their own activity and discuss with their surgeon objective mobilization goals will not only help patients achieve empowerment in their own care but also improve their overall satisfaction and self-reported outcomes after spine surgery.

    Stanford is currently not accepting patients for this trial. For more information, please contact Megan Tang, BA, 831-277-9234.

    View full details

2023-24 Courses

Stanford Advisees

All Publications

  • Provider's exposure to diversity contributes to socioeconomic disparities in lumbar and cervical fusion outcomes. World neurosurgery: X Touponse, G., Malacon, K., Li, G., Yoseph, E., Han, S., Zygourakis, C. 2024; 23: 100382


    Studies report patient race, income, and education influence spinal fusion outcomes; fewer studies, however, examine the influence of provider factors such as exposure to diversity or cultural sensitivity.To examine how providers' experience with diverse patient populations affects spinal fusion outcomes.Retrospective review of 39,680 patients undergoing lumbar and cervical fusions, 2003-2021, in Clinformatics® Data Mart national database. We used the provider patient racial diversity index (pRDI)-a published metric of physician exposure to diverse patients-to divide patients into groups based their provider's category (I, II, III) where patients treated by category III providers had surgeons with the most diverse patient populations. Multivariate regression models on propensity score-matched cohorts examined the association between patient SES and provider category on post-operative outcomes.Black patients had decreased discharge home (OR 0.67; 95% CI 0.54-0.83) compared to white patients. Patients treated by category III providers had increased length of stay (Coeff. 0.62; 95% CI 0.43-0.81), charge (Coeff. 36800; 95% CI 29,200-44,400), and decreased discharge home (OR 0.90; 95% CI 0.83-0.97) compared to patients treated by category I providers. Asian patients treated by category II providers had decreased readmission (OR 0.38; 95% CI 0.14-0.96), and Black patients treated by category III providers had increased discharge home (OR 1.41; 95% CI 1.1-1.9) compared to those treated by category I providers.While our study found two specific instances of improved spine surgery outcomes for minority patients treated by providers serving diverse patient populations, we present mixed findings overall. This study serves as the foundation for future research to better understand how provider pRDI affects outcomes in patients undergoing lumbar and cervical spine surgery.

    View details for DOI 10.1016/j.wnsx.2024.100382

    View details for PubMedID 38756754

    View details for PubMedCentralID PMC11097082

  • Socioeconomic disparities in lumbar fusion rates were exacerbated during the COVID-19 pandemic. North American Spine Society journal Wu, J. Y., Tang, M., Touponse, G., Theologitis, M., Williamson, T., Zygourakis, C. C. 2024; 18: 100321


    Background: The COVID-19 pandemic disrupted healthcare access and utilization throughout the US, with variable impact on patients of different socioeconomic status (SES) and race. We characterize pre-pandemic and pandemic demographic and SES trends of lumbar fusion patients in the US.Methods: Adults undergoing first-time lumbar fusion 1/1/2004-3/31/2021 were assessed in Clinformatics Data Mart for patient age, geographical location, gender, race, education level, net worth, and Charlson Comorbidity Index (CCI). Multivariable regression models were used to evaluate the significance of trends over time, with a focus on pandemic trends 2020-2021 versus previous trends 2004-2019.Results: The total 217,204 patients underwent lumbar fusions, 1/1/2004-3/31/2021. The numbers and per capita rates of lumbar fusions increased 2004-2019 and decreased in 2020 (first year of COVID-19 pandemic), with large variation in geographic distribution. There was overall a significant decrease in proportion of White patients undergoing lumbar fusion over time (OR=0.997, p<.001), though they were more likely to undergo surgery during the pandemic (OR=1.016, p<.001). From 2004-2021, patients were more likely to be educated beyond high school. Additionally, patients in the highest (>$500k) and lowest (<$25k) net worth categories had significantly more fusions over time (p<.001). During the pandemic (2020-2021), patients in higher net worth groups were more likely to undergo lumbar fusions ($150k-249k & $250k-499k: p<.001) whereas patients in the lowest net worth group had decreased rate of surgeries (p<.001). Lastly, patients' CCI increased significantly from 2004 to 2021 (coefficient=0.124, p<.001), and this trend held true during the pandemic (coefficient=0.179, p<.001).Conclusions: To the best of our knowledge, our work represents the most comprehensive and recent characterization of SES variables in lumbar fusion rates. Unsurprisingly, lumbar fusions decreased overall with the onset of the COVID-19 pandemic. Importantly, disparities in fusion patients across patient race and wealth widened during the pandemic, reversing years of progress, a lesson we can learn for future public health emergencies.

    View details for DOI 10.1016/j.xnsj.2024.100321

    View details for PubMedID 38741936

  • Standardizing Continuous Physical Activity Monitoring in Patients with Cervical Spondylosis. Spine Maldaner, N., Gonzalez-Suarez, A. D., Tang, M., Fatemi, P., Leung, C., Desai, A., Tomkins-Lane, C., Zygourakis, C. 2024


    STUDY DESIGN/SETTING: Prospective cohort study.OBJECTIVE: To use a commercial wearable device to measure real-life, continuous physical activity in patients with CS and to establish age- and sex-adjusted standardized scores.SUMMARY OF BACKGROUND DATA: Patients with cervical spondylosis (CS) often present with pain or neurologic deficits that results in functional limitations and inactivity. However, little is known regarding the influence of CS on patient's real-life physical activity.METHODS: This study included 100 English-speaking adult patients with cervical degenerative diseases undergoing elective spine surgery at Stanford University who owned iPhones. Patients undergoing surgery for spine infections, trauma, or tumors, or with lumbar degenerative disease were excluded. Activity two weeks before surgery was expressed as raw daily step counts. Standardized z-scores were calculated based on age- and sex-specific values of a control population. Responses to patient-reported outcome measures (PROMs) surveys assessed convergent validity. Functional impairment was categorized based on predetermined z-score cut-off values.RESULTS: 30 CS with mean(±SD) age of 56.0(±13.4) years wore an Apple Watch for ≥8 hours/day in 87.1% of the days. Mean watch wear time was 15.7(±4.2) hours/day, and mean daily step count was 6,400(±3,792). There was no significant difference in activity between 13 patients (43%) with myelopathy and 17 (57%) without myelopathy. Test-Retest reliability between wearable step count measurements was excellent (ICC beta=0.95). Physical activity showed a moderate positive correlation with SF36-PCS, EQ5D VAS, and PROMIS-PF. Activity performance was classified into categories of "no impairment" (step count=9,640(±2,412)), "mild impairment" (6,054(±816)), "moderate impairment" (3,481(±752)), and "severe impairment" (1,619(±240)).CONCLUSION: CS patients' physical activity is significantly lower than the general population, or the frequently stated goals of 7,000-10,000 steps/day. Standardized, continuous wearable physical activity monitoring in CS is a reliable, valid, and normalized outcome tool that may help characterize functional impairment before and after spinal interventions.

    View details for DOI 10.1097/BRS.0000000000004940

    View details for PubMedID 38288595

  • Demographic and Socioeconomic Trends in Cervical Fusion Utilization from 2004 through 2021 and the COVID-19 Pandemic. World neurosurgery Wu, J. Y., Touponse, G. C., Theologitis, M., Ahmad, H. S., Zygourakis, C. C. 2023


    Cervical fusion rates increased in the US exponentially 1990-2014, but trends leading up to/during the COVID-19 pandemic have not been fully evaluated by patient socioeconomic status (SES). Here we provide the most recent, comprehensive characterization of demographic and SES trends in cervical fusions, including during the pandemic.We collected the following variables on adults undergoing cervical fusions, 1/1/2004-3/31/2021, in Optum's Clinformatics® Data Mart: age, Charlson Comorbidity Index, provider's practicing state, gender, race, education, and net worth. We performed multivariate linear and logistic regression to evaluate associations of cervical fusion rates with SES variables.Cervical fusion rates increased 2004-2016, then decreased 2016-2020. Proportions of Asian, Black, and Hispanic patients undergoing cervical fusions increased (OR=1.001,1.001,1.004, p<0.01), with a corresponding decrease in White patients (OR=0.996, p<0.001) over time. There were increases in cervical fusions in higher education groups (OR=1.006, 1.002, p<0.001) and lowest net worth group (OR=1.012, p<0.001). During the pandemic, proportions of White (OR=1.015, p<0.01) and wealthier patients (OR≥1.015, p<0.01) undergoing cervical fusions increased.We present the first documented decrease in annual cervical surgery rates in the U.S. Our data reveal a bimodal distribution for cervical fusion patients, with racial-minority, lower-net-worth, and highly-educated patients receiving increasing proportions of surgical interventions. White and wealthier patients were more likely to undergo cervical fusions during the COVID-19 pandemic, which has been reported in other areas of medicine but not yet in spine surgery. There is still considerable work needed to improve equitable access to spine care for the entire U.S.

    View details for DOI 10.1016/j.wneu.2023.11.055

    View details for PubMedID 38000672

  • Standardizing Physical Activity Monitoring in Patients With Degenerative Lumbar Disorders. Neurosurgery Maldaner, N., Tang, M., Fatemi, P., Leung, C., Desai, A., Tomkins-Lane, C., Zygourakis, C. 2023


    Degenerative thoracolumbar disorders (DTDs) typically cause pain and functional impairment. However, little is known regarding the DTD impact on patient's real-life physical activity. The objective of this study is to validate a wearable measure of physical activity monitoring in patients with DTD and to create gender- and sex-specific performance thresholds that are standardized to the mean of a control population.A commercially available smartwatch (Apple Watch) was used to monitor preoperative physical activity in patients undergoing surgery for DTD. Mean preoperative physical activity 2 weeks before the scheduled surgery was expressed as raw step count. Standardized z-scores were referenced to age- and sex-specific values of a control population from a large public database. Step counts were assessed for convergent validity with established patient-reported outcome measures, and impairment in activity was stratified into performance groups based on z-score cutoff values.Sixty-five patients (62% female) with a mean (±SD) age of 63.8 (±12.8) years had a mean preoperative daily step count of 5556 (±3978). Physical activity showed significant correlation with patient-reported outcome measures, including Oswestry disability index (r = -0.26, 95% CI: -0.47-0.01), 36-Item Short Form Survey Physical Component Summary score (r = 0.30, 95% CI: 0.06-0.51), and Patient-Reported Outcomes Measurement Information System Physical Function (r = 0.49, 95% CI: 0.27-0.65). "No," "Mild," "moderate," and "severe impairment" in activity performance were defined as corresponding z-scores of >0, 0 to -0.99, -1 to -1.99, and ≤-2, accounting for 22%, 34%, 40%, and 5% of the study population. Each one-step category increase in activity impairment resulted in increased subjective disability as measured by the Oswestry Disability Index, 36-Item Short Form Survey Physical Component Summary, and Patient-Reported Outcomes Measurement Information System Physical Function (all P-values <.05).We establish the first wearable objective measure of real-life physical activity for patients with DTD, with the first age- and sex-adjusted standard scores to enable clinicians and researchers to set treatment goals and directly compare activity levels between individual patients with DTD and normal controls.

    View details for DOI 10.1227/neu.0000000000002755

    View details for PubMedID 37955445

  • First spine surgery utilizing real-time image-guided robotic assistance. Computer assisted surgery (Abingdon, England) Ahmed, A. K., Zygourakis, C. C., Kalb, S., Zhu, A. M., Molina, C. A., Jiang, B., Blitz, A. M., Bydon, A., Crawford, N. R., Theodore, N. 2019: 1–5


    Robotics in spinal surgery has significant potential benefits for both surgeons and patients, including reduced surgeon fatigue, improved screw accuracy, decreased radiation exposure, greater options for minimally invasive surgery, and less time required to train residents on techniques that can have steep learning curves. However, previous robotic systems have several drawbacks, which are addressed by the innovative ExcelsiusGPSTM robotic system. The robot is secured to the operating room floor, not the patient. It has a rigid external arm that facilitates direct transpedicular drilling and screw placement, without requiring K-wires. In addition, the ExcelsisuGPSTM has integrated neuronavigation, not present in other systems. It also has surveillance marker that immediately alerts the surgeon in the event of loss of registration, and a lateral force meter to alert the surgeon in the event of skiving. Here, we present the first spinal surgery performed with the assistance of this newly approved robot. The surgery was performed with excellent screw placement, minimal radiation exposure to the patient and surgeon, and the patient had a favorable outcome. We report the first operative case with the ExcelsisuGPSTM, and the first spine surgery utilizing real-time image-guided robotic assistance.

    View details for PubMedID 30821536

  • Technique: open lumbar decompression and fusion with the Excelsius GPS robot. Neurosurgical focus Zygourakis, C. C., Ahmed, A. K., Kalb, S. n., Zhu, A. M., Bydon, A. n., Crawford, N. R., Theodore, N. n. 2018; 45 (VideoSuppl1): V6


    The Excelsius GPS (Globus Medical, Inc.) was approved by the FDA in 2017. This novel robot allows for real-time intraoperative imaging, registration, and direct screw insertion through a rigid external arm-without the need for interspinous clamps or K-wires. The authors present one of the first operative cases utilizing the Excelsius GPS robotic system in spinal surgery. A 75-year-old man presented with severe lower back pain and left leg radiculopathy. He had previously undergone 3 decompressive surgeries from L3 to L5, with evidence of instability and loss of sagittal balance. Robotic assistance was utilized to perform a revision decompression with instrumented fusion from L3 to S1. The usage of robotic assistance in spinal surgery may be an invaluable resource in minimally invasive cases, minimizing the need for fluoroscopy, or in those with abnormal anatomical landmarks. The video can be found here: .

    View details for PubMedID 29963912

  • Association Between Surgeon Scorecard Use and Operating Room Costs. JAMA surgery Zygourakis, C. C., Valencia, V. n., Moriates, C. n., Boscardin, C. K., Catschegn, S. n., Rajkomar, A. n., Bozic, K. J., Soo Hoo, K. n., Goldberg, A. N., Pitts, L. n., Lawton, M. T., Dudley, R. A., Gonzales, R. n. 2017; 152 (3): 284–91


    Despite the significant contribution of surgical spending to health care costs, most surgeons are unaware of their operating room costs.To examine the association between providing surgeons with individualized cost feedback and surgical supply costs in the operating room.The OR Surgical Cost Reduction (OR SCORE) project was a single-health system, multihospital, multidepartmental prospective controlled study in an urban academic setting. Intervention participants were attending surgeons in orthopedic surgery, otolaryngology-head and neck surgery, and neurological surgery (n = 63). Control participants were attending surgeons in cardiothoracic surgery, general surgery, vascular surgery, pediatric surgery, obstetrics/gynecology, ophthalmology, and urology (n = 186).From January 1 to December 31, 2015, each surgeon in the intervention group received standardized monthly scorecards showing the median surgical supply direct cost for each procedure type performed in the prior month compared with the surgeon's baseline (July 1, 2012, to November 30, 2014) and compared with all surgeons at the institution performing the same procedure at baseline. All surgical departments were eligible for a financial incentive if they met a 5% cost reduction goal.The primary outcome was each group's median surgical supply cost per case. Secondary outcome measures included total departmental surgical supply costs, case mix index-adjusted median surgical supply costs, patient outcomes (30-day readmission, 30-day mortality, and discharge status), and surgeon responses to a postintervention study-specific health care value survey.The median surgical supply direct costs per case decreased 6.54% in the intervention group, from $1398 (interquartile range [IQR], $316-$5181) (10 637 cases) in 2014 to $1307 (IQR, $319-$5037) (11 820 cases) in 2015. In contrast, the median surgical supply direct cost increased 7.42% in the control group, from $712 (IQR, $202-$1602) (16 441 cases) in 2014 to $765 (IQR, $233-$1719) (17 227 cases) in 2015. This decrease represents a total savings of $836 147 in the intervention group during the 1-year study. After controlling for surgeon, department, patient demographics, and clinical indicators in a mixed-effects model, there was a 9.95% (95% CI, 3.55%-15.93%; P = .003) surgical supply cost decrease in the intervention group over 1 year. Patient outcomes were equivalent or improved after the intervention, and surgeons who received scorecards reported higher levels of cost awareness on the health care value survey compared with controls.Cost feedback to surgeons, combined with a small departmental financial incentive, was associated with significantly reduced surgical supply costs, without negatively affecting patient outcomes.

    View details for PubMedID 27926758

  • In Reply: Women Neurosurgeons Worldwide: Characterizing the Global Female Neurosurgical Workforce. Neurosurgery Vaca, S. D., Theologitis, M., Zygourakis, C. C. 2024

    View details for DOI 10.1227/neu.0000000000003104

    View details for PubMedID 38953640

  • Acute back pain: The role of medication, physical medicine and rehabilitation: WFNS spine committee recommendations. World neurosurgery: X Sharif, S., Jazaib Ali, M. Y., Kirazlı, Y., Vlok, I., Zygourakis, C., Zileli, M. 2024; 23: 100273


    To formulate the most current, evidence-based recommendations for the role of medication, physical medicine, and rehabilitation in the management of acute low back pain lasting <4 weeks.A systematic literature search in PubMed and Google Scholar databases was performed from 2012 to 2022 using the search terms "acute low back pain," "drugs," "bed rest," "physical medicine," rehabilitation." Standardized screening criteria resulted in a total of 39 articles that were analyzed, including 16 RCTs, 8 prospective studies, 6 retrospective studies, and 9 systematic reviews. This up-to-date information was reviewed and presented at two separate meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. Two rounds of the Delphi method were utilized to vote on the statements and arrive at a positive or negative consensus.The WFNS Spine Committee finalized twelve recommendation guidelines on the role of medication, physical medicine and rehabilitation in the management of acute LBP. We advocate for a uniform approach to the treatment of these patients, including proper patient education and utilizing drugs with proven efficacy and minimal side effects. First-line pharmacologic agents are acetaminophen and NSAIDs; muscle relaxants can be used for spasms and pain reduction, and opioids should be minimized. Continued activity, rather than bed rest, is recommended, and lumbar spine orthotics may be used to reduce pain and augment functional status. Thermotherapy, cryotherapy, TENs, spinal manipulative therapy, and acupuncture may all be used as adjuncts to improve acute LBP.

    View details for DOI 10.1016/j.wnsx.2024.100273

    View details for PubMedID 38807862

    View details for PubMedCentralID PMC11130729

  • Analyzing Large Language Models' Responses to Common Lumbar Spine Fusion Surgery Questions: A Comparison Between ChatGPT and Bard. Neurospine Lang, S. P., Yoseph, E. T., Gonzalez-Suarez, A. D., Kim, R., Fatemi, P., Wagner, K., Maldaner, N., Stienen, M. N., Zygourakis, C. C. 2024; 21 (2): 633-641


    In the digital age, patients turn to online sources for lumbar spine fusion information, necessitating a careful study of large language models (LLMs) like chat generative pre-trained transformer (ChatGPT) for patient education.Our study aims to assess the response quality of Open AI (artificial intelligence)'s ChatGPT 3.5 and Google's Bard to patient questions on lumbar spine fusion surgery. We identified 10 critical questions from 158 frequently asked ones via Google search, which were then presented to both chatbots. Five blinded spine surgeons rated the responses on a 4-point scale from 'unsatisfactory' to 'excellent.' The clarity and professionalism of the answers were also evaluated using a 5-point Likert scale.In our evaluation of 10 questions across ChatGPT 3.5 and Bard, 97% of responses were rated as excellent or satisfactory. Specifically, ChatGPT had 62% excellent and 32% minimally clarifying responses, with only 6% needing moderate or substantial clarification. Bard's responses were 66% excellent and 24% minimally clarifying, with 10% requiring more clarification. No significant difference was found in the overall rating distribution between the 2 models. Both struggled with 3 specific questions regarding surgical risks, success rates, and selection of surgical approaches (Q3, Q4, and Q5). Interrater reliability was low for both models (ChatGPT: k = 0.041, p = 0.622; Bard: k = -0.040, p = 0.601). While both scored well on understanding and empathy, Bard received marginally lower ratings in empathy and professionalism.ChatGPT3.5 and Bard effectively answered lumbar spine fusion FAQs, but further training and research are needed to solidify LLMs' role in medical education and healthcare communication.

    View details for DOI 10.14245/ns.2448098.049

    View details for PubMedID 38955533

  • Acute back pain - Role of injection techniques and surgery: WFNS spine committee recommendations. World neurosurgery: X Peev, N., Zygourakis, C., Sippl, C., Grasso, G., Oertel, J., Sharif, S. 2024; 22: 100315


    Lower back pain is a significant cause of morbidity, and despite a range of interventions available, there is a lack of consensus on the most efficacious treatments. The aim of this systematic review is to formulate a list of recommendations for the role of spinal injections and surgery in the treatment of acute back pain.A systematic literature search from 2012 to 2022 was conducted on Pubmed, Medline, and Cochrane Central Register of Controlled Trials for papers focusing on the role of injections and surgery for the management of acute lower back pain. Inclusion criteria included randomised controlled trials, as well as prospective and retrospective studies reporting primary outcomes (pain improvement (VAS score) and back-specific functional status) and secondary outcomes (post-procedure complications). These data were reviewed, presented, and voted on by an expert panel consisting of 14 attending spine surgeons from 14 countries at the consensus meeting of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. A two-round consensus-based Delphi method was used to generate consensus, and topics with >66% agreement were categorized as having reached consensus.100 studies met inclusion criteria. Of these, 20 were selected by the committee for full text review and presented at the consensus meeting. The committee voted on 8 statements and achieved consensus on the following 7 statements: (1) Epidural steroid injections (ESIs) show significant benefit to discogenic back pain; (2) A lateral approach is superior to a midline approach for ESIs; (3) Short-term (<1 week) effect of ESIs is similar between steroids; (4) ESIs have a variety of potential complications; (5) CT or fluoroscopy guidance can be used for lumbar medial branch blocks; (6) Lumbar medial branch radiofrequency ablations can be performed on patients with recurrent pain after a successful ESI, and (7) Acute lower back pain is usually self-limiting, resolves in <6 weeks, and does not require surgical intervention.Given significant treatment heterogeneity, we provide the latest, evidence-based recommendations for management of acute lower back pain. ESIs are effective at short-term pain relief, and surgical intervention should be reserved for patients failing conservative measures.

    View details for DOI 10.1016/j.wnsx.2024.100315

    View details for PubMedID 38550557

    View details for PubMedCentralID PMC10973205

  • Lumbar disc herniation: Epidemiology, clinical and radiologic diagnosis WFNS spine committee recommendations. World neurosurgery: X Pojskic, M., Bisson, E., Oertel, J., Takami, T., Zygourakis, C., Costa, F. 2024; 22: 100279


    To formulate the most current, evidence-based recommendations regarding the epidemiology, clinical diagnosis, and radiographic diagnosis of lumbar herniated disk (LDH).A systematic literature search in PubMed, MEDLINE, and CENTRAL was performed from 2012 to 2022 using the search terms "herniated lumbar disc", "epidemiology", "prevention" "clinical diagnosis", and "radiological diagnosis". Screening criteria resulted in 17, 16, and 90 studies respectively that were analyzed regarding epidemiology, clinical diagnosis, and radiographic diagnosis of LDH. Using the Delphi method and two rounds of voting at two separate international meetings, ten members of the WFNS (World Federation of Neurosurgical Societies) Spine Committee generated eleven final consensus statements.The lifetime risk for symptomatic LDH is 1-3%; of these, 60-90% resolve spontaneously. Risk factors for LDH include genetic and environmental factors, strenuous activity, and smoking. LDH is more common in males and in 30-50 year olds. A set of clinical tests, including manual muscle testing, sensory testing, Lasegue sign, and crossed Lasegue sign are recommended to diagnose LDH. Magnetic resonance imaging (MRI) is the gold standard for confirming suspected LDH.These eleven final consensus statements provide current, evidence-based guidelines on the epidemiology, clinical diagnosis, and radiographic diagnosis of LDH for practicing spine surgeons worldwide.

    View details for DOI 10.1016/j.wnsx.2024.100279

    View details for PubMedID 38440379

    View details for PubMedCentralID PMC10911853

  • Lumbar disc herniation: Prevention and treatment of recurrence: WFNS spine committee recommendations. World neurosurgery: X Zileli, M., Oertel, J., Sharif, S., Zygourakis, C. 2024; 22: 100275


    Objective: This review aims to formulate the most current evidence-based recommendations on the epidemiology, prevention, and treatment of recurrent lumbar disc herniation (LDH).Methods: We performed a systematic literature search in PubMed, Medline, and Google Scholar databases from 2012 to 2022 using the keywords "lumbar disc recurrence." Screening criteria resulted in 57 papers, which were summarized and presented at two international consensus meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. The 57 papers covered the following topics: (1) Definition and incidence of recurrence after lumbar disc surgery; (2) Prediction of recurrence before primary surgery; (3) Prevention of recurrence by surgical measures; (4) Prevention of recurrence by postoperative measures; (5) Treatment options for recurrent disc herniation; (6) The outcomes of recurrent disc herniation surgery. We utilized the Delphi method and voted on eight final consensus statements.Results and conclusion: Recurrence after disc herniation surgery may be considered a surgical complication, its incidence is approximately 5% and is different from overall re-operation incidence. There are multiple risk factors predicting LDH recurrence, including smoking, younger age, male gender, obesity, diabetes, disc degeneration, and presence of lumbosacral transitional vertebrae. The level of lumbar discectomy surgery and the amount of disc material removed do not correlate with recurrence rate. Minimally invasive discectomies may have higher recurrence rates, especially during the surgeon's learning period. However, the experience of the surgeon is not related to recurrence. High-quality studies are needed to determine if activity restriction, weight loss, smoking cessation, and muscle-strengthening exercises after primary surgery can help prevent recurrence of LDH.The best treatment option for recurrent disc herniation is still being discussed. While complications of minimally invasive techniques may be lower than open discectomy, outcomes are similar. Fusion should only be considered when spinal instability and/or spinal deformity are present. Clinical outcomes and patient satisfaction after recurrent disc herniation surgery are inferior to those after initial discectomy.

    View details for DOI 10.1016/j.wnsx.2024.100275

    View details for PubMedID 38385057

  • The role of conservative treatment in lumbar disc herniations: WFNS spine committee recommendations. World neurosurgery: X Yaman, O., Guchkha, A., Vaishya, S., Zileli, M., Zygourakis, C., Oertel, J. 2024; 22: 100277


    Objective: To formulate the most current, evidence-based recommendations for the conservative management of lumbar disc herniations (LDH).Methods: A systematic literature search was performed 2012-2022 in PubMed/Medline and Cochrane using the keywords ''lumbar disc herniation'' and ''conservative treatment,'' yielding 342 total manuscripts. Screening criteria resulted in 12 final manuscripts which were summarized and presented at two international consensus meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. The Delphi method was utilized to arrive at three final consensus statements.Results and conclusion: s: In the absence of cauda equina syndrome, motor, or other serious neurologic deficits, conservative treatment should be the first line of treatment for LDH. NSAIDs may significantly improve acute low back and sciatic pain caused by LDH. A combination of activity modification, pharmacotherapy, and physical therapy provides good outcomes in most LDH patients.

    View details for DOI 10.1016/j.wnsx.2024.100277

    View details for PubMedID 38389961

  • Acute back pain: Clinical and radiologic diagnosis: WFNS spine committee recommendations. World neurosurgery: X Gushcha, A. O., Sharif, S., Zileli, M., Oertel, J., Zygourakis, C. C., Yusupova, A. R. 2024; 22: 100278


    Objective: To formulate the most current, evidence-based recommendations for the clinical and radiologic diagnosis of acute low back pain lasting <4 weeks.Methods: A systematic literature search in PubMed and Google Scholar databases was performed from 2012 to 2022 using the search terms "acute back pain AND clinical diagnosis" and "acute back pain AND radiologic diagnosis". Screening criteria resulted in a total of 97 papers analyzed. Using the Delphi method and two rounds of voting, the WFNS (World Federation of Neurosurgical Societies) Spine Committee generated ten final consensus statements.Results: Ten final consensus statements address the clinical diagnosis of acute LBP, including which clinical conditions cause acute LBP and how we can distinguish between the different causes of LBP, including discogenic, facet joint, sacroiliac joint, and myofascial pain. The most important step for the radiologic diagnosis of acute LBP is to evaluate the necessity of radiologic investigation, as well as its timing and the most appropriate type of imaging modality. Importantly, imaging should not be a routine diagnostic tool, unless red flag signs are present. In fact, routine imaging for acute LBP can actually have a negative effect as it may reveal incidental radiographic findings that exacerbate patient fear and anxiety.Conclusion: Overall, the quality of evidence is not high for most of our consensus statements, and further studies are needed to validate the WFNS Spine Committee recommendations on the clinical and radiographic diagnosis of acute LBP.

    View details for DOI 10.1016/j.wnsx.2024.100278

    View details for PubMedID 38389960

  • Acute low back pain: Epidemiology, etiology, and prevention: WFNS spine committee recommendations. World neurosurgery: X Oertel, J., Sharif, S., Zygourakis, C., Sippl, C. 2024; 22: 100313


    Acute low back pain is a highly prevalent condition that poses significant challenges to healthcare systems worldwide. In this manuscript, we present the most current, evidence-based guidelines from the World Federation of Neurosurgical Societies (WFNS) Spine Committee on the epidemiology, etiology, and prevention of acute low back pain (LBP) lasting ≤ 4 weeks.We performed a literature review 2012-2022 using the PubMed, Medline, and CENTRAL databases with the keywords "acute low back pain", "acute back pain", "low back pain", "epidemiology", "etiology", "costs", "risk factor", "cultural", "developed", "developing" and "prevention". Systematic screening criteria were applied, resulting in 13 final articles on epidemiology and etiology of LBP, 2 manuscripts on costs, 5 articles on risk factors, and 23 articles on prevention strategies for acute LBP. These were presented at two separate international meetings, where members of the WFNS Spine Committee voted on five final consensus statements presented here.and Conclusions: There is a high incidence and prevalence of acute LBP, particularly in high-income countries, which is felt to be at least partially due to demographic shifts with an aging population and lifestyle changes including higher rates of obesity and physical inactivity. Acute LBP has a significant impact on quality of life and ability to work, resulting in high direct and indirect costs worldwide. Early diagnosis and appropriate management of acute LBP is recommended to prevent this pain from turning into chronic LBP. The WFNS Spine Committee's recommendations respresent the latest guidelies to help improve patient care for acute LBP worldwide.

    View details for DOI 10.1016/j.wnsx.2024.100313

    View details for PubMedID 38510335

    View details for PubMedCentralID PMC10951075

  • Role of surgery in primary lumbar disk herniation: WFNS spine committee recommendations. World neurosurgery: X Costa, F., Oertel, J., Zileli, M., Restelli, F., Zygourakis, C. C., Sharif, S. 2024; 22: 100276


    Objective: To provide the most up-to-date recommendations on the role of surgery in first-time lumbar disk herniations (LDH) in order to standardize surgical management.Methods: We performed a literature search in PubMed, Scopus, and Embase from 2012 to 2022 using the following keywords: "lumbar disk herniation AND surgery". Our initial search yielded 2610 results, which were narrowed down to 283 papers after standardized screening critera were applied. The data from these 283 papers were presented and discussed at two international meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee, where the Delphi method was employed and ten spine experts voted on five final consensus statements.Results: and Conclusions: The WFNS Spine Committee's guidelines cover four main topics: (1) role and timing of surgery in first-time LDH; (2) role of minimally invasive techniques in LDH; (3) extent of disk resection in LDH surgery; (4) role of lumbar fusion in the context of LDH. Surgery for LDH is recommended for failure of conservative treatment, cauda equina syndrome, and progressive neurological impairment, including severe motor deficits. In the latter cases, early surgery is associated with faster recovery and may improve patient outcomes. Minimally invasive techniques have short-term advantages over open procedures, but there is insufficient evidence to make a recommendation for or against the choice of a specific surgical procedure. Sequestrectomy and standard microdiscectomy demonstrated similar clinical results in terms of pain control, recurrence rate, functional outcome, and complications at short and medium-term follow-up. Lumbar fusion is not recommended as a routine treatment for first-time LDH, although it may be considered in specific patients affected by chronic axial pain or instability.

    View details for DOI 10.1016/j.wnsx.2024.100276

    View details for PubMedID 38496347

  • Cauda equina, conus medullaris and syndromes mimicking sciatic pain: WFNS spine committee recommendations. World neurosurgery: X Vaishya, S., Pojskic, M., Bedi, M. S., Oertel, J., Sippl, C., Robertson, S., Zygourakis, C. 2024; 22: 100274


    Introduction: Cauda equina syndrome (CES), conus medullaris syndrome (CMS), and sciatica-like syndromes or "sciatica mimics" (SM) may present as diagnostic and/or therapeutic dilemmas for the practicing spine surgeon. There is considerable controversy regarding the appropriate definition and diagnosis of these entities, as well as indications for and timing of surgery. Our goal is to formulate the most current, evidence-based recommendations for the definition, diagnosis, and management of CES, CMS, and SM syndromes.Methods: We performed a systematic literature search in PubMed from 2012 to 2022 using the keywords "cauda equina syndrome", "conus medullaris syndrome", "sciatica", and "sciatica mimics". Standardized screening criteria yielded a total of 43 manuscripts, whose data was summarized and presented at two international consensus meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. Utilizing the Delphi method, we generated seven final consensus statements.Results and conclusion: s: We provide standardized definitions of cauda equina, cauda equina syndrome, conus medullaris, and conus medullaris syndrome. We advocate for the use of the Lavy et al classification system to categorize different types of CES, and recommend urgent MRI in all patients with suspected CES (CESS), considering the low sensitivity of clinical examination in excluding CES. Surgical decompression for CES and CMS is recommended within 48h, preferably within less than 24h. There is no data regarding the role of steroids in acute CES or CMS. The treating physician should be cognizant of a variety of other pathologies that may mimic sciatica, including piriformis syndrome, and how to manage these.

    View details for DOI 10.1016/j.wnsx.2024.100274

    View details for PubMedID 38496349

  • Getting What You Pay For: Impact of Copayments on Physical Therapy and Opioid Initiation, Timing, and Continuation for Newly Diagnosed Low Back Pain. The spine journal : official journal of the North American Spine Society Jin, M. C., Jensen, M., Barros Guinle, M. I., Ren, A., Zhou, Z., Zygourakis, C. C., Desai, A. M., Veeravagu, A., Ratliff, J. K. 2024


    Physical therapy (PT) is an important component of low back pain (LBP) management. Despite established guidelines, heterogeneity in medical management remains common.We sought to understand how copayments impact timing and utilization of PT in newly diagnosed LBP.The IBM Watson Health MarketScan claims database was utilized in a longitudinal setting.Adult patients with LBP.The primary outcomes-of-interest were timing and overall utilization of PT services. Additional outcomes-of-interest included timing of opioid prescribing.Actual and inferred copayments based on non-PCP visit claims were used to evaluate the relationship between PT copayment and incidence of PT initiation. Multivariable regression models were used to evaluate factors influencing PT usage.Overall, 2,467,389 patients were included. PT initiation, among those with at ≥1 PT service during the year after LBP diagnosis (30.6%), occurred at a median of 8 days post-diagnosis (IQR 1-55). Among those with at least one PT encounter, incidence of subsequent PT visits was significantly lower for those with high initial PT copayments. High initial PT copayments, while inversely correlated with PT utilization, were directly correlated with subsequent opioid use (0.77 prescriptions/patient [$0 PT copayment] vs 1.07 prescriptions/patient [$50-74 PT copayment]; 1.15 prescriptions/patient [$75+ PT copayment]). Among patients with known opioid and PT copayments, higher PT copayments were correlated with faster opioid use while higher opioid copayments were correlated with faster PT use (Spearman p < 0.05). For multivariable whole-cohort analyses, incidence of PT initiation among patients with inferred copayments in the 50-75th and 75th-100th percentiles was significantly lower than those below the 50th percentile (HR=0.893 [95%CI 0.887-0.899] and HR=0.905 [95%CI 0.899-0.912], respectively).Higher PT copayments correlated with reduced PT utilization; higher PT copayments and lower opioid copayments were independent contributors to delayed PT initiation and higher opioid use. In patients covered by plans charging high PT copayments, opioid use was significantly higher. Co-pays may impact long-term adherence to PT.

    View details for DOI 10.1016/j.spinee.2024.01.008

    View details for PubMedID 38262499

  • Women Neurosurgeons Worldwide: Characterizing the Global Female Neurosurgical Workforce. Neurosurgery Vaca, S. D., Theologitis, M., Zygourakis, C. C. 2023


    BACKGROUND AND OBJECTIVES: As the global neurosurgical workforce expands, so do the contributions of women neurosurgeons. Recent studies highlighted pioneering women leaders in neurosurgery and provided invaluable perspectives into the proportion of women neurosurgeons in regions across the world. To provide a broad perspective of global trends, this study aims to characterize the global female neurosurgical workforce and evaluate its association with countries' economic status, broader physician workforce, and global gender gap index (GGGI).METHODS: A literature search included studies dated 2016-2023 characterizing the neurosurgical workforce. Total neurosurgeons, neurosurgeons per capita, and percent of women neurosurgeons by country were collected or calculated from available data. Countries were stratified by World Health Organization (WHO) region, World Bank economic classification, WHO physician workforce, and GGGI. Poisson regressions and Spearman correlation tests were performed to evaluate the association between each country's percent of women neurosurgeons and their economic classification, WHO physician workforce, and GGGI.RESULTS: Neurosurgical workforce data were obtained for 210 nations; world maps were created demonstrating neurosurgeons per capita and proportion of women neurosurgeons. Africa had the fewest neurosurgeons (1296) yet highest percentage of women neurosurgeons (15%). A total of 94 of 210 (45%) countries met the minimum requirement of neurosurgeons needed to address neurotrauma. Compared with low-income countries, upper-middle-income and high-income countries had 27.5 times greater the rate of neurosurgeons per capita but only 1.02 and 2.57 times greater percentage of women neurosurgeons, respectively (P < .001). There was a statistically significant association between GGI and women neurosurgeons (P < .001) and a weak correlation between proportion of women in physician workforce and women neurosurgeons (P = .019, rho = 0.33).CONCLUSION: Much progress has been made in expanding the neurosurgical workforce and the proportion of women within it, but disparities remain. As we address the global neurosurgeon deficit, improving recruitment and retention of women neurosurgeons through mentorship, collaboration, and structural support is essential.

    View details for DOI 10.1227/neu.0000000000002796

    View details for PubMedID 38084996

  • Costs and Outcomes of Total Joint Arthroplasty in Medicare Beneficiaries Are Not Meaningfully Associated with Industry Payments. The Journal of bone and joint surgery. American volume Wadhwa, H., Leung, C., Sklar, M., Malacon, K., Rangwalla, T., Williamson, T., Castillo, T. N., Amanatullah, D. F., Zygourakis, C. C. 2023


    BACKGROUND: Prior studies have demonstrated that industry payments affect physician prescribing patterns, but their effect on orthopaedic surgical costs is unknown. This study examines the relationship between industry payments and the total costs of primary total joint arthroplasty, as well as operating room cost, length of stay, 30-day mortality, and 30-day readmission.METHODS: Open Payments data were matched across a 20% sample of Medicare-insured patients undergoing primary elective total hip arthroplasty (THA) (n = 130,872) performed by 7,539 surgeons or primary elective total knee arthroplasty (TKA) (n = 230,856) performed by 8,977 surgeons from 2013 to 2015. Patient, hospital, and surgeon-specific factors were gathered. Total and operating room costs, length of stay, mortality, and readmissions were recorded. Multivariable linear and logistic regression models were used to identify the risk-adjusted relationships between industry payments and the primary and secondary outcomes.RESULTS: In this study, 96.7% of THA surgeons and 97.4% of TKA surgeons received industry payments. After multivariable risk adjustment, for each $1,000 increase in industry payments, the total costs of THA increased by $0.50 (0.003% of total costs) and the operating room costs of THA increased by $0.20 (0.003% of total costs). Industry payments were not associated with TKA cost. Industry payments were not associated with 30-day mortality after either THA or TKA. Higher industry payments were independently associated with a marginal decrease in the length of stay for patients undergoing THA (0.0045 days per $1,000) or TKA (0.0035 days per $1,000) and a <0.1% increase in the odds of 30-day readmission after THA for every $1,000 in industry payments. The median total THA costs were $300 higher (p < 0.001), whereas the median TKA costs were $150 lower (p < 0.001), for surgeons receiving the highest 5% of industry payments. These surgical procedures were more often performed in large urban areas, in hospitals with a higher number of beds, with a higher wage index, and by more experienced surgeons and were associated with a 0.4 to 1-day shorter length of stay (p < 0.001).CONCLUSIONS: Although most arthroplasty surgeons received industry payments, a minority of surgeons received the majority of payments. Overall, arthroplasty costs and outcomes were not meaningfully impacted by industry relationships.LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

    View details for DOI 10.2106/JBJS.23.00768

    View details for PubMedID 37992189

  • Thoracic and Lumbar Spine Injury: Evidence-Based Diagnosis, Management, and Outcomes. The American surgeon Gomez, G. I., Li, G. Q., Valido, A. A., Stoner, A. J., Bromley-Dulfano, R. A., Sheira, D., Gonzalez, C. A., Khan, S. I., Choi, J., Zygourakis, C. C., Weiser, T. G. 2023: 31348231216479


    Traumatic thoracolumbar spine injuries are associated with significant morbidity and mortality. Targeted for non-spine specialist trauma surgeons, this systematic scoping review aimed to examine literature for up-to-date evidence on presentation, management, and outcomes of thoracolumbar spine injuries in adult trauma patients.This review was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. We searched four bibliographic databases: PubMed, EMBASE, Web of Science, and the Cochrane Library. Eligible studies included experimental, observational, and evidence-synthesis articles evaluating patients with thoracic, lumbar, or thoracolumbar spine injury, published in English between January 1, 2010 and January 31, 2021. Studies which focused on animals, cadavers, cohorts with N <30, and pediatric cohorts (age <18 years old), as well as case studies, abstracts, and commentaries were excluded.A total of 2501 studies were screened, of which 326 unique studies were fully text reviewed and twelve aspects of injury management were identified and discussed: injury patterns, determination of injury status and imaging options, considerations in management, and patient quality of life. We found: (1) imaging is a necessary diagnostic tool, (2) no consensus exists for preferred injury characterization scoring systems, (3) operative management should be considered for unstable fractures, decompression, and deformity, and (4) certain patients experience significant burden following injury.In this systematic scoping review, we present the most up-to-date information regarding the management of traumatic thoracolumbar spine injuries. This allows non-specialist trauma surgeons to become more familiar with thoracolumbar spine injuries in trauma patients and provides a framework for their management.

    View details for DOI 10.1177/00031348231216479

    View details for PubMedID 37983195

  • Anabolic and Antiresorptive Osteoporosis Treatment: Trends, Costs, and Sequence in a Commercially Insured Population, 2003-2021. JBMR plus Wadhwa, H., Wu, J. Y., Lee, J. S., Zygourakis, C. C. 2023; 7 (10): e10800


    New anabolic medications (abaloparatide and romosozumab) were recently approved for osteoporosis, and data suggest that prescribing antiresorptive medications after a course of anabolic medications offers better outcomes. This study aimed to characterize prescription trends, demographics, geographical distributions, out-of-pocket costs, and treatment sequences for anabolic and antiresorptive osteoporosis medications. Using a commercial claims database (Clinformatics Data Mart), adult patients with osteoporosis from 2003 to 2021 were retrospectively reviewed and stratified based on osteoporosis medication class. Patient demographics and socioeconomic variables, provider types, and out-of-pocket costs were collected. Multivariable regression analyses were used to identify independent predictors of receiving osteoporosis treatment. A total of 2,988,826 patients with osteoporosis were identified; 616,635 (20.6%) received treatment. Patients who were female, Hispanic or Asian, in the Western US, had higher net worth, or had greater comorbidity burden were more likely to receive osteoporosis medications. Among patients who received medication, 31,112 (5.0%) received anabolic medication; these were more likely to be younger, White patients with higher education level, net worth, and greater comorbidity burden. Providers who prescribed the most anabolic medications were rheumatologists (18.5%), endocrinologists (16.8%), and general internists (15.3%). Osteoporosis medication prescriptions increased fourfold from 2003 to 2020, whereas anabolic medication prescriptions did not increase at this rate. Median out-of-pocket costs were $17 higher for anabolic than antiresorptive medications, though costs for anabolic medications decreased significantly from 2003 to 2020 (compound annual growth rate: -0.6%). A total of 8388 (1.4%) patients tried two or more osteoporosis medications, and 0.6% followed the optimal treatment sequence. Prescription of anabolic osteoporosis medications has not kept pace with overall osteoporosis treatment, and there are socioeconomic disparities in anabolic medication prescription, potentially driven by higher median out-of-pocket costs. Although prescribing antiresorptive medications after a course of anabolic medications offers better outcomes, this treatment sequence occurred in only 0.6% of the study cohort. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

    View details for DOI 10.1002/jbm4.10800

    View details for PubMedID 37808398

    View details for PubMedCentralID PMC10556263

  • Socioeconomic Influence on Cervical Fusion Outcomes. Clinical spine surgery Touponse, G., Theologitis, M., Beach, I., Rangwalla, T., Li, G., Zygourakis, C. 2023


    A retrospective observational study.The aim of this study was to compare postoperative outcomes following cervical fusion based on socioeconomic status (SES) variables including race, education, net worth, and homeownership status.Previous studies have demonstrated the effects of patient race and income on outcomes following cervical fusion procedures. However, no study to date has comprehensively examined the impact of multiple SES variables. We hypothesized that race, education, net worth, and homeownership influence important outcomes following cervical fusion.Optum's de-identified Clinformatics Data Mart (CDM) database was queried for patients undergoing first-time inpatient cervical fusion from 2003 to 2021. Patient demographics, SES variables, and the Charlson comorbidity index were obtained. Primary outcomes were hospital length of stay and 30-day rates of reoperation, readmission, and postoperative complications. Secondary outcomes included postoperative emergency room visits, discharge status, and total hospital charges.A total of 111,914 patients underwent cervical spinal fusion from 2003 to 2021. Multivariate analysis revealed that after controlling for age, sex, and Charlson comorbidity index, Black race was associated with a higher rate of 30-day readmissions [odds ratio (OR): 1.11, 95% CI: 1.03-1.20]. Lower net worth (vs. >$500K) and renting (vs. owning a home) were significantly associated with both higher rates of 30-day readmissions (OR: 1.29, 95% CI: 1.17-1.41; OR: 1.34, 95% CI: 1.22-1.49), and emergency room visits (OR: 1.29, 95% CI: 1.18-1.42; OR: 1.11, 95% CI: 1.00-1.23). Lower net worth (vs. >$500K) was also associated with increased complications (OR: 1.22, 95% CI: 1.14-1.31).Socioeconomic variables, including patient race, education, and net worth, influence postoperative metrics in cervical spinal fusion surgery. Future studies should focus on developing and implementing targeted interventions based on patient SES to reduce disparity.

    View details for DOI 10.1097/BSD.0000000000001533

    View details for PubMedID 37691156

  • Anabolic and Antiresorptive Osteoporosis Treatment: Trends, Costs, and Sequence in a Commercially Insured Population, 2003-2021 JBMR PLUS Wadhwa, H., Wu, J. Y., Lee, J. S., Zygourakis, C. C. 2023

    View details for DOI 10.1002/jbm4.10800

    View details for Web of Science ID 001035628600001

  • Trends in Management of Osteoporosis Following Primary Vertebral Compression Fracture. Journal of the Endocrine Society Malacon, K., Beach, I., Touponse, G., Rangwalla, T., Lee, J., Zygourakis, C. 2023; 7 (7): bvad085


    Osteoporosis affects more than 200 million individuals worldwide and predisposes to vertebral compression fractures (VCFs). Given undertreatment of fragility fractures, including VCFs, we investigate current anti-osteoporotic medication prescribing trends.Patients 50 and older with a diagnosis of primary closed thoracolumbar VCF between 2004 and 2019 were identified from the Clinformatics® Data Mart database. Multivariate analysis was performed for demographic and clinical treatment and outcome variables.Of 143 081 patients with primary VCFs, 16 780 (11.7%) were started on anti-osteoporotic medication within a year; 126 301 (88.3%) patients were not started on medication. The medication cohort was older (75.4 ± 9.3 vs 74.0 ± 12.3 years, P < .001), had higher Elixhauser Comorbidity Index scores (4.7 ± 6.2 vs 4.3 ± 6.7, P < .001), was more likely to be female (81.1% vs 64.4%, P < .001), and was more likely to have a formal osteoporosis diagnosis (47.8% vs 32.9%) than the group that did not receive medication. Alendronate (63.4%) and calcitonin (27.8%) were the most commonly initiated medications. The proportion of individuals receiving anti-osteoporotic medication within the year following VCF peaked in 2008 (15.2%), then declined until 2012 with a modest increase afterward.Osteoporosis remains undertreated after low-energy VCFs. New anti-osteoporotic medication classes have been approved in recent years. Bisphosphonates remain the most prescribed class. Increasing recognition and treatment of osteoporosis is paramount to decreasing the risk of subsequent fractures.

    View details for DOI 10.1210/jendso/bvad085

    View details for PubMedID 37388575

    View details for PubMedCentralID PMC10306270

  • Trends, Payments, and Costs Associated with BMP Use in Medicare Beneficiaries Undergoing Spinal Fusion. The spine journal : official journal of the North American Spine Society Wadhwa, H., Wu, J. Y., Malacon, K., Ames, C., Ratliff, J., Zygourakis, C. 2023


    Bone morphogenic protein (BMP) promotes bony fusion but increases costs. Recent trends in BMP use among Medicare patients have not been well-characterized.To assess utilization trends, complication, payments, and costs associated with BMP use in spinal fusion in a Medicare-insured population.Retrospective cohort study PATIENT SAMPLE: : 316,070 patients who underwent spinal fusion in a 20% sample of Medicare-insured patients, 2006-2015 OUTCOME MEASURES: : Utilization trends across time and geography, complications, payments, and costs.Patients were stratified by fusion type and diagnosis. Multivariable logistic and linear regression were used to adjust for the effect of baseline characteristics on complications and total payments or cost, respectively.BMP was used in 60,249 cases (19.1%). BMP utilization rates decreased from 23.1% in 2006 to 12.0% in 2015, most significantly in anterior cervical (7.5% to 3.1%), posterior cervical (17.0% to 8.3%), and posterior lumbar fusions (31.5% to 15.8%). There are significant state- and region-level geographic differences in BMP utilization. Across all years, states with the highest BMP use were Indiana (28.5%), Colorado (26.6%), and Nevada (25.7%). States with the lowest BMP use were Maine (2.3%), Vermont (8.2%), and Mississippi (10.4%). After multivariate risk adjustment, BMP use was associated with decreased overall complications in thoracic (OR (95% CI): 0.89 (0.81-0.99) and anterior lumbar fusions (OR (95% CI): 0.89 (0.84-0.95)), as well as increased reoperation rates in anterior cervical (OR (95% CI): 1.11 (1.04-1.19)), posterior cervical (OR (95% CI): 1.14 (1.04-1.25)), thoracic (OR (95% CI): 1.32 (1.23-1.41)), and posterior lumbar fusions (OR (95% CI): 1.11 (1.06-1.16)). BMP use was also associated with greater total costs, independent of fusion type, after multivariate risk adjustment (p < 0.0001). Payments, however, were comparable between groups in anterior and posterior cervical fusion with or without BMP. BMP use was associated with greater total payments in thoracic, anterior lumbar, and posterior lumbar fusions. Notably, the difference in payments was smaller than the associated cost increase in all fusion types.BMP use has declined across all fusion types over the last decade, after a peak in 2007. While BMP is associated with greater costs, reimbursement does not increase proportionally with BMP cost.

    View details for DOI 10.1016/j.spinee.2023.01.012

    View details for PubMedID 36709918

  • Socioeconomic Effects on Lumbar Fusion Outcomes. Neurosurgery Touponse, G., Li, G., Rangwalla, T., Beach, I., Zygourakis, C. 2023


    BACKGROUND: Recent studies suggest that socioeconomic status (SES) influences outcomes after spinal fusion. The influence of SES on postoperative outcomes is increasingly relevant as rates of lumbar fusion rise.OBJECTIVE: To determine the influence of SES variables including race, education, net worth, and homeownership on postoperative outcomes.METHODS: Optum's deidentified Clinformatics Data Mart Database was used to conduct a retrospective review of SES variables for patients undergoing first-time, inpatient lumbar fusion from 2003 to 2021. Primary outcomes included hospital length of stay (LOS) and 30-day reoperation, readmission, and postoperative complication rates. Secondary outcomes included postoperative emergency room visits, discharge status, and total hospital charges.RESULTS: In total, 217204 patients were identified. On multivariate analysis, Asian, Black, and Hispanic races were associated with increased LOS (Coeff. [coefficient] 0.92, 95% CI 0.68-1.15; Coeff. 0.61, 95% CI 0.51-0.71; Coeff. 0.43, 95% CI 0.32-0.55). Less than 12th grade education (vs greater than a bachelor's degree) was associated with increased odds of reoperation (OR [odds ratio] 1.88, 95% CI 1.03-3.42). Decreased net worth was associated with increased odds of readmission (OR 1.32, 95% CI 1.25-1.40) and complication (OR 1.14, 95% CI 1.10-1.20). Renting a home (vs homeownership) was associated with increased LOS, readmissions, and total charges (Coeff. 0.30, 95% CI 0.17-0.43; OR 1.19, 95% CI 1.11-1.30; Coeff. 13200, 95% CI 9000-17000).CONCLUSION: Black race, less than 12th grade education, <$25K net worth, and lack of homeownership were associated with poorer postoperative outcomes and increased costs. Increasing perioperative support for patients with these sociodemographic risk factors may improve postoperative outcomes.

    View details for DOI 10.1227/neu.0000000000002322

    View details for PubMedID 36606803

  • First reported use of machine vision image guided system for unstable thoracolumbar fusion: Technical case report INTERDISCIPLINARY NEUROSURGERY-ADVANCED TECHNIQUES AND CASE MANAGEMENT Malacon, K., Fatemi, P., Zygourakis, C. C. 2022; 30
  • Utilization Trends, Cost, and Payments for Adult Spinal Deformity Surgery in Commercial and Medicare-Insured Populations. Neurosurgery Wadhwa, H., Leung, C., Sklar, M., Ames, C. P., Veeravagu, A., Desai, A., Ratliff, J., Zygourakis, C. C. 2022


    BACKGROUND: Previous studies have characterized utilization rates and cost of adult spinal deformity (ASD) surgery, but the differences between these factors in commercially insured and Medicare populations are not well studied.OBJECTIVE: To identify predictors of increased payments for ASD surgery in commercially insured and Medicare populations.METHODS: We identified adult patients who underwent fusion for ASD, 2007 to 2015, in 20% Medicare inpatient file (n = 21614) and MarketScan commercial insurance database (n = 38789). Patient age, sex, race, insurance type, geographical region, Charlson Comorbidity Index, and length of stay were collected. Outcomes included predictors of increased payments, surgical utilization rates, total cost (calculated using Medicare charges and hospital-specific charge-to-cost ratios), and total Medicare and commercial payments for ASD.RESULTS: Rates of fusion increased from 9.0 to 8.4 per 10000 in 2007 to 20.7 and 18.2 per 10000 in 2015 in commercial and Medicare populations, respectively. The Medicare median total charges increased from $88106 to $144367 (compound annual growth rate, CAGR: 5.6%), and the median total cost increased from $31846 to $39852 (CAGR: 2.5%). Commercial median total payments increased from $58164 in 2007 to $64634 in 2015 (CAGR: 1.2%) while Medicare median total payments decreased from $31415 in 2007 to $25959 in 2015 (CAGR: -2.1%). The Northeast and Western regions were associated with higher payments in both populations, but there is substantial state-level variation.CONCLUSION: Rate of ASD surgery increased from 2007 to 2015 among commercial and Medicare beneficiaries. Despite increasing costs, Medicare payments decreased. Age, length of stay, and BMP usage were associated with increased payments for ASD surgery in both populations.

    View details for DOI 10.1227/neu.0000000000002140

    View details for PubMedID 36136402

  • Operative Versus Nonoperative Management of Unstable Spine Fractures in the Elderly: Outcomes and Mortality. Spine Malacon, K., Rangwalla, T., Wadhwa, H., Zygourakis, C. 2022


    STUDY DESIGN: Retrospective cohort study.OBJECTIVE: To assess outcomes and mortality in elderly patients following unstable spine fractures depending on treatment modality.SUMMARY OF BACKGROUND DATA: Operative management of unstable spine fractures in the elderly remains controversial due to increased risk of perioperative complications. Mortality rates after operative versus nonoperative treatment of these injuries have not been well-characterized.METHODS: Patients age >65 with unstable spine fractures without neurologic injury from 2015-2021 were identified from the Clinformatics Data Mart (CDM) Database. Demographics, complications, and mortality were collected. Multivariable logistic regression was used to adjust for the effect of baseline characteristics on mortality following unstable fracture diagnosis.RESULTS: Of 3,688 patients included, 1,330 (36.1%) underwent operative management and 2,358 (63.9%) nonoperative. At baseline, nonoperative patients were older, female, had higher Elixhauser comorbidity scores, and were more likely to have a cervical fracture. Operative patients had a longer length of stay in the hospital compared to nonoperative patients (9.7 vs. 7.7d; P<0.001). Although patients in the operative group had higher rates of readmission at 30-, 60-, 90-, and 120-days after diagnosis (P<0.01), they had lower mortality rates up to 5 years after injury. After adjusting for covariates, nonoperative patients had a 60% greater risk of mortality compared to operative patients (HR: 1.60 [1.40-1.78], P<0.001). After propensity score matching, operative patients age 65-85 had greater survivorship compared to their nonoperative counterparts.CONCLUSION: Elderly patients with an unstable spine fracture who undergo surgery experience lower mortality rates up to five years post diagnosis compared to patients who received nonoperative management, despite higher hospital readmission rates and an overall perioperative complication rate of 37.3%. Operating on elderly patients with unstable spine fractures may outweigh the risks and should be considered as a viable treatment option in appropriately selected patients.

    View details for DOI 10.1097/BRS.0000000000004466

    View details for PubMedID 36083602

  • Health Care Resource Utilization in Management of Opioid-Naive Patients With Newly Diagnosed Neck Pain. JAMA network open Jin, M. C., Jensen, M., Zhou, Z., Rodrigues, A., Ren, A., Barros Guinle, M. I., Veeravagu, A., Zygourakis, C. C., Desai, A. M., Ratliff, J. K. 2022; 5 (7): e2222062


    Importance: Research has uncovered heterogeneity and inefficiencies in the management of idiopathic low back pain, but few studies have examined longitudinal care patterns following newly diagnosed neck pain.Objective: To understand health care utilization in patients with new-onset idiopathic neck pain.Design, Setting, and Participants: This cross-sectional study used nationally sourced longitudinal data from the IBM Watson Health MarketScan claims database (2007-2016). Participants included adult patients with newly diagnosed neck pain, no recent opioid use, and at least 1 year of continuous postdiagnosis follow-up. Exclusion criteria included prior or concomitant diagnosis of traumatic cervical disc dislocation, vertebral fractures, myelopathy, and/or cancer. Only patients with at least 1 year of prediagnosis lookback were included. Data analysis was performed from January 2021 to January 2022.Main Outcomes and Measures: The primary outcome of interest was 1-year postdiagnosis health care expenditures, including costs, opioid use, and health care service utilization. Early services were those received within 30 days of diagnosis. Multivariable regression models and regression-adjusted statistics were used.Results: In total, 679 030 patients (310 665 men [45.6%]) met the inclusion criteria, of whom 7858 (1.2%) underwent surgery within 1 year of diagnosis. The mean (SD) age was 44.62 (14.87) years among nonsurgical patients and 49.69 (9.53) years among surgical patients. Adjusting for demographics and comorbidities, 1-year regression-adjusted health care costs were $24 267.55 per surgical patient and $515.69 per nonsurgical patient. Across all health care services, $95 379 949 was accounted for by nonsurgical patients undergoing early imaging who did not receive any additional conservative therapy or epidural steroid injections, for a mean (SD) of $477.53 ($1375.60) per patient and median (IQR) of $120.60 ($20.70-$452.37) per patient. On average, patients not undergoing surgery, physical therapy, chiropractic manipulative therapy, or epidural steroid injection, who underwent either early advanced imaging (magnetic resonance imaging or computed tomography) or both early advanced and radiographic imaging, accumulated significantly elevated health care costs ($850.69 and $1181.67, respectively). Early conservative therapy was independently associated with 24.8% (95% CI, 23.5%-26.2%) lower health care costs.Conclusions and Relevance: In this cross-sectional study, early imaging without subsequent intervention was associated with significantly increased health care spending among patients with newly diagnosed idiopathic neck pain. Early conservative therapy was associated with lower costs, even with increased frequency of therapeutic services, and may have reduced long-term care inefficiency.

    View details for DOI 10.1001/jamanetworkopen.2022.22062

    View details for PubMedID 35816312

  • Modifiers of and Disparities in Palliative and Supportive Care Timing and Utilization among Neurosurgical Patients with Malignant Central Nervous System Tumors. Cancers Jin, M. C., Hsin, G., Ratliff, J., Thomas, R., Zygourakis, C. C., Li, G., Wu, A. 2022; 14 (10)


    Patients with primary or secondary central nervous system (CNS) malignancies benefit from utilization of palliative care (PC) in addition to other supportive services, such as home health and social work. Guidelines propose early initiation of PC for patients with advanced cancers. We analyzed a cohort of privately insured patients with malignant brain or spinal tumors derived from the Optum Clinformatics Datamart Database to investigate health disparities in access to and utilization of supportive services. We introduce a novel construct, "provider patient racial diversity index" (provider pRDI), which is a measure of the proportion of non-white minority patients a provider encounters to approximate a provider's patient demographics and suggest a provider's cultural sensitivity and exposure to diversity. Our analysis demonstrates low rates of PC, home health, and social work services among racial minority patients. Notably, Hispanic patients had low likelihood of engaging with all three categories of supportive services. However, patients who saw providers categorized into high provider pRDI (categories II and III) were increasingly more likely to interface with supportive care services and at an earlier point in their disease courses. This study suggests that prospective studies that examine potential interventions at the provider level, including diversity training, are needed.

    View details for DOI 10.3390/cancers14102567

    View details for PubMedID 35626171

  • Trends in Intraoperative Assessment of Spinal Alignment: A Survey of Spine Surgeons in the United States. Global spine journal Gullotti, D. M., Soltanianzadeh, A. H., Fujita, S., Inserni, M., Ruppel, E. 3., Franconi, N. G., Zygourakis, C., Protopsaltis, T., Lo, S. L., Sciubba, D. M., Theodore, N. 2022; 12 (2_suppl): 82S-86S


    STUDY DESIGN: Survey.OBJECTIVES: To characterize national practices of and shortcomings surrounding intraoperative assessments of spinal alignment.METHODS: Spine surgeons in the US were surveyed to analyze their experience with assessing spinal alignment intraoperatively.RESULTS: 108 US spine surgeons from 77 surgical centers with an average of 19.2 + 8.8 years of surgical experience completed the survey. To assess alignment intraoperatively, 84% (91/108) use C-arm or spot radiographs, 40% (43/108) use full-length radiographs, and 20% utilize the T-bar (22/108). 88% of respondents' surgical centers (93/106) possessed a navigation camera and 63% of respondents (68/108) report using surgical navigation for 40% of their deformity cases on average. Reported deterrents for using current technology to assess alignment were workflow interruption (54%, 58/108), expense (33%, 36/108), and added radiation exposure (26%, 28/108). 87% of respondents (82/94) reported a need for improvement in current capabilities of making intraoperative assessments of spinal alignment.CONCLUSIONS: Corrective surgery for spinal deformity is a complex procedure that requires a high level of expertise to perform safely. The majority of surveyed surgeons primarily rely on radiographs for intraoperative assessments of alignment. Despite the majority of surveyed surgical practices possessing navigation cameras, they are utilized only for a minority of spinal deformity cases. With the majority of surveyed surgeons reporting a need for improvement in technology to assess spinal alignment intraoperatively, 3 of the top design considerations should include workflow interruption, expense, and radiation exposure.

    View details for DOI 10.1177/21925682211037273

    View details for PubMedID 35393882

  • Appropriate Telemedicine Utilization in Spine Surgery: Results From a Delphi Study. Spine Iyer, S., Bovonratwet, P., Samartzis, D., Schoenfeld, A. J., An, H. S., Awwad, W., Blumenthal, S. L., Cheung, J. P., Derman, P. B., El-Sharkawi, M., Freedman, B. A., Hartl, R., Kang, J. D., Kim, H. J., Louie, P. K., Ludwig, S. C., Neva, M. H., Pham, M. H., Phillips, F. M., Qureshi, S. A., Radcliff, K. E., Riew, K. D., Sandhu, H. S., Sciubba, D. M., Sethi, R. K., Valacco, M., Zaidi, H. A., Zygourakis, C. C., Makhni, M. C. 2022


    STUDY DESIGN: Delphi expert panel consensus.OBJECTIVE: To obtain expert consensus on best practices for appropriate telemedicine utilization in spine surgery.SUMMARY OF BACKGROUND DATA: Several studies have shown high patient satisfaction associated with telemedicine during the COVID-19 peak pandemic period as well as after easing of restrictions. As this technology will most likely continue to be employed, there is a need to define appropriate utilization.METHODS: An expert panel consisting of 27 spine surgeons from various countries was assembled in February 2021. A two-round consensus-based Delphi method was used to generate consensus statements on various aspects of telemedicine (separated as video visits or audio visits) including themes, such as patient location and impact of patient diagnosis, on assessment of new patients. Topics with ≥75% agreement were categorized as having achieved a consensus.RESULTS: The expert panel reviewed a total of 59 statements. Of these, 32 achieved consensus. The panel had consensus that video visits could be utilized regardless of patient location and that video visits are appropriate for evaluating as well as indicating for surgery multiple common spine pathologies, such as lumbar stenosis, lumbar radiculopathy, and cervical radiculopathy. Finally, the panel had consensus that video visits could be appropriate for a variety of visit types including early, mid-term, longer-term post-operative follow-up, follow-up for imaging review, and follow-up after an intervention (i.e. physical therapy, injection).CONCLUSIONS: Although telemedicine was initially introduced out of necessity, this technology most likely will remain due to evidence of high patient satisfaction and significant cost savings. This study was able to provide a framework for appropriate telemedicine utilization in spine surgery from a panel of experts. However, several questions remain for future research, such as whether or not an in-person consultation is necessary prior to surgery and which physical exam maneuvers are appropriate for telemedicine.Level of Evidence: IV.

    View details for DOI 10.1097/BRS.0000000000004339

    View details for PubMedID 35125460

  • Introduction. The neurosurgeon as roboticist. Neurosurgical focus Theodore, N., Chambless, L. B., Hartl, R., Zygourakis, C. C., Jiang, B., Protopsaltis, T. S. 1800; 52 (1): E1

    View details for DOI 10.3171/2021.10.FOCUS21634

    View details for PubMedID 34973680

  • First case report using optical topographic-guided navigation in revision spinal fusion for calcified thoracic disk. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Sklar, M., Fatemi, P., Wadhwa, H., Leung, C., Zygourakis, C. 2021; 91: 80-83


    Computer assisted navigation systems are frequently used in spine surgery to improve the accuracy of pedicle screw placement. The 7D Surgical System utilizes optical topographic imaging (OTI) with a camera positioned directly above the surgical field to perform rapid registration from a pre-operative CT scan onto anatomical landmarks with zero intra-operative radiation exposure. This current technology requires an open approach with well-exposed bony anatomy, raising concerns about using the 7D Surgical System in revision surgery, where typical anatomical landmarks may be altered, missing, or obscured by prior hardware. To overcome this, the 7D Surgical System is capable of registering off prior hardware. Here, we present the first published report of 7D Surgical System's registration off prior hardware in a revision spinal fusion. The registration was accurate, and the workflow was easy and efficient with one registration required for 3 levels of instrumentation and discectomy/corpectomy. This demonstrates that the 7D Surgical System can be used in revision cases with altered, missing, or obscured anatomy.

    View details for DOI 10.1016/j.jocn.2021.06.031

    View details for PubMedID 34373063

  • Predictors of an academic career among fellowship-trained spinal neurosurgeons. Journal of neurosurgery. Spine Khalafallah, A. M., Jimenez, A. E., Shlobin, N. A., Larkin, C. J., Mukherjee, D., Zygourakis, C. C., Lo, S., Sciubba, D. M., Bydon, A., Witham, T. F., Dahdaleh, N. S., Theodore, N. 2021: 1-8


    OBJECTIVE: Although fellowship training is becoming increasingly common in neurosurgery, it is unclear which factors predict an academic career trajectory among spinal neurosurgeons. In this study, the authors sought to identify predictors associated with academic career placement among fellowship-trained neurological spinal surgeons.METHODS: Demographic data and bibliometric information on neurosurgeons who completed a residency program accredited by the Accreditation Council for Graduate Medical Education between 1983 and 2019 were gathered, and those who completed a spine fellowship were identified. Employment was denoted as academic if the hospital where a neurosurgeon worked was affiliated with a neurosurgical residency program; all other positions were denoted as nonacademic. A logistic regression model was used for multivariate statistical analysis.RESULTS: A total of 376 fellowship-trained spinal neurosurgeons were identified, of whom 140 (37.2%) held academic positions. The top 5 programs that graduated the most fellows in the cohort were Cleveland Clinic, The Johns Hopkins Hospital, University of Miami, Barrow Neurological Institute, and Northwestern University. On multivariate analysis, increased protected research time during residency (OR 1.03, p = 0.044), a higher h-index during residency (OR 1.12, p < 0.001), completing more than one clinical fellowship (OR 2.16, p = 0.024), and attending any of the top 5 programs that graduated the most fellows (OR 2.01, p = 0.0069) were independently associated with an academic career trajectory.CONCLUSIONS: Increased protected research time during residency, a higher h-index during residency, completing more than one clinical fellowship, and attending one of the 5 programs graduating the most fellowship-trained neurosurgical spinal surgeons independently predicted an academic career. These results may be useful in identifying and advising trainees interested in academic spine neurosurgery.

    View details for DOI 10.3171/2020.12.SPINE201771

    View details for PubMedID 34116505

  • External validation of a predictive model of adverse events following spine surgery. The spine journal : official journal of the North American Spine Society Fatemi, P., Zhang, Y., Han, S. S., Purington, N., Zygourakis, C. C., Veeravagu, A., Desai, A., Park, J., Shuer, L. M., Ratliff, J. K. 2021


    BACKGROUND CONTEXT: We lack models that reliably predict 30-day postoperative adverse events (AEs) following spine surgery.PURPOSE: We externally validated a previously developed predictive model for common 30-day adverse events (AEs) after spine surgery.STUDY DESIGN/SETTING: This prospective cohort study utilizes inpatient and outpatient data from a tertiary academic medical center.PATIENT SAMPLE: We assessed a prospective cohort of all 276 adult patients undergoing spine surgery in the Department of Neurosurgery at a tertiary academic institution between April 1, 2018 and October 31, 2018. No exclusion criteria were applied.OUTCOME MEASURES: Incidence of observed AEs was compared with predicted incidence of AEs. Fifteen assessed AEs included: pulmonary complications, congestive heart failure, neurological complications, pneumonia, cardiac dysrhythmia, renal failure, myocardial infarction, wound infection, pulmonary embolus, deep venous thrombosis, wound hematoma, other wound complication, urinary tract infection, delirium, and other infection.METHODS: Our group previously developed the Risk Assessment Tool for Adverse Events after Spine Surgery (RAT-Spine), a predictive model of AEs within 30 days following spine surgery using a cohort of approximately one million patients from combined Medicare and MarketScan databases. We applied RAT-Spine to the single academic institution prospective cohort by entering each patient's preoperative medical and demographic characteristics and surgical type. The model generated a patient-specific overall risk score ranging from 0 to 1 representing the probability of occurrence of any AE. The predicted risks are presented as absolute percent risk and divided into low (<17%), medium (17-28%), and high (>28%).RESULTS: Among the 276 patients followed prospectively, 76 experienced at least one 30-day postoperative AE. Slightly more than half of the cohort were women (53.3%). The median age was slightly lower in the non-AE cohort (63 vs 66.5 years old). Patients with Medicaid comprised 2.5% of the non-AE cohort and 6.6% of the AE cohort. Spinal fusion was performed in 59.1% of cases, which was comparable across cohorts. There was good agreement between the predicted AE and observed AE rates, Area Under the Curve (AUC) 0.64 (95% CI 0.56-0.710). The incidence of observed AEs in the prospective cohort was 17.8% among the low-risk group, 23.0% in the medium-risk group, and 38.4% in the high risk group (p = 0.003).CONCLUSIONS: We externally validated a model for postoperative AEs following spine surgery (RAT-Spine). The results are presented as low-, moderate-, and high-risk designations.

    View details for DOI 10.1016/j.spinee.2021.06.006

    View details for PubMedID 34116215

  • First reported use of real-time intraoperative computed tomography angiography image registration using the Machine-vision Image Guided Surgery system: illustrative case. Journal of neurosurgery. Case lessons Wadhwa, H., Malacon, K., Medress, Z. A., Leung, C., Sklar, M., Zygourakis, C. C. 2021; 1 (18): CASE2125


    Vertebral artery injury is a devastating potential complication of C1-2 posterior fusion. Intraoperative navigation can reduce the risk of neurovascular complications and improve screw placement accuracy. However, the use of intraoperative computed tomography (CT) increases radiation exposure and operative time, and it is unable to image vascular structures. The Machine-vision Image Guided Surgery (MvIGS) system uses optical topographic imaging and machine vision software to rapidly register using preoperative imaging. The authors presented the first report of intraoperative navigation with MvIGS registered using a preoperative CT angiogram (CTA) during C1-2 posterior fusion.MvIGS can register in seconds, minimizing operative time with no additional radiation exposure. Furthermore, surgeons can better adjust for abnormal vertebral artery anatomy and increase procedure safety.CTA-guided navigation generated a three-dimensional reconstruction of cervical spine anatomy that assisted surgeons during the procedure. Although further study is needed, the use of intraoperative MvIGS may reduce the risk of vertebral artery injury during C1-2 posterior fusion.

    View details for DOI 10.3171/CASE2125

    View details for PubMedID 35855470

    View details for PubMedCentralID PMC9245760

  • Commentary: Transdural Spinal Cord Herniation: An Exceptional Complication of Thoracoscopic Discectomy. Operative neurosurgery (Hagerstown, Md.) Jensen, M., Zygourakis, C. 2021

    View details for DOI 10.1093/ons/opab083

    View details for PubMedID 33825873

  • Telehealth Adoption Across Neurosurgical Subspecialties at a Single Academic Institution During the COVID-19 Pandemic. World neurosurgery Leung, C., Wadhwa, H., Sklar, M., Sheth, K., Loo, S., Ratliff, J., Zygourakis, C. C. 2021


    OBJECTIVE: The COVID-19 pandemic has dramatically changed healthcare, forcing providers to adopt and implement telehealth technology to provide continuous care for their patients. Amid this rapid transition from in-person to remote visits, differences in telehealth utilization have arisen among neurosurgical subspecialties. In this study, we analyze the impact of telehealth on neurosurgical healthcare delivery during the COVID-19 pandemic at our institution and highlight differences in telehealth utilization across different neurosurgical subspecialties.METHODS: To quantify differences in telehealth utilization, we analyzed all outpatient neurosurgery visits at a single academic institution. Internal surveys were administered to neurosurgeons and to patients to determine both physician and patient satisfaction with telehealth visits. Patient Likelihood-to-Recommend Press Ganey scores were also evaluated.RESULTS: There was a decrease in outpatient visits during the COVID-19 pandemic in all neurosurgical subspecialties. Telehealth adoption was higher in spine, tumor, and interventional pain than in functional, peripheral nerve, or vascular neurosurgery. Neurosurgeons agreed that telehealth was an efficient (92%) and effective (85%) methodology; however, they noted it was more difficult to evaluate and bond with patients. The majority of patients were satisfied with their video visits and would recommend video visits over in-person visits.CONCLUSIONS: During the COVID-19 pandemic, neurosurgical subspecialties varied in adoption of telehealth, which may be due to the specific nature of each subspecialty and their necessity to perform in-person evaluations. Telehealth visits will likely continue after the pandemic as they can improve clinical efficiency; overall both patients and physicians are satisfied with healthcare delivery over video.

    View details for DOI 10.1016/j.wneu.2021.03.062

    View details for PubMedID 33746106

  • Functional neurological disorders in patients undergoing spinal surgery: illustrative case. Journal of neurosurgery. Case lessons Yerneni, K., Wadhwa, H., Fatemi, P., Zygourakis, C. C. 2021; 1 (2): CASE2068


    "Conversion disorder" refers to bodily dysfunction characterized by either sensory or motor neurological symptoms that are unexplainable by a medical condition. Given their somatosensory context, such disorders often require extensive medical evaluation, and the diagnosis can only be made after structural disease is excluded or fails to account for the severity and/or spectrum of the patient's deficits.The authors briefly review functional psychiatric disorders and discuss the comprehensive workup of a patient with a functional postoperative neurological deficit, drawing from their recent experience with a patient who presented with conversion disorder immediately after undergoing anterior cervical discectomy and fusion.Conversion disorder has been found to be associated with bodily stress, requiring surgeons to be aware of this condition in the postoperative setting. This is especially true in neurosurgery, given the overlap of true neurological pathology, postoperative complications, and manifestations of conversion disorder. Although accurately diagnosing and managing patients with conversion disorder remains challenging, an understanding of the multifactorial nature of its etiology can help clinicians develop a methodical approach to this condition.

    View details for DOI 10.3171/CASE2068

    View details for PubMedID 35854933

    View details for PubMedCentralID PMC9241316

  • Functional neurological disorders in patients undergoing spinal surgery: illustrative case Journal of Neurosurgery: Case Lessons Yerneni, K., Wadhwa, H., Fatemi, P., Zygourakis, C. C. 2021; 1 (2)

    View details for DOI 10.3171/CASE2068

  • First reported use of real-time intraoperative computed tomography angiography image registration using the Machine-vision Image Guided Surgery system: illustrative case Journal of Neurosurgery: Case Lessons Wadhwa, H., Malacon, K., Medress, Z. A., Leung, C., Sklar, M., Zygourakis, C. C. 2021

    View details for DOI 10.3171/CASE2125

  • Posterior Vertebral Column Subtraction Osteotomy for Recurrent Tethered Cord Syndrome: A Multicenter, Retrospective Analysis. Neurosurgery Theodore, N., Cottrill, E., Kalb, S., Zygourakis, C., Jiang, B., Pennington, Z., Lubelski, D., Westbroek, E. M., Ahmed, A. K., Ehresman, J., Sciubba, D. M., Witham, T. F., Turner, J. D., Groves, M., Kakarla, U. K. 2020


    BACKGROUND: Few have explored the safety and efficacy of posterior vertebral column subtraction osteotomy (PVCSO) to treat tethered cord syndrome (TCS).OBJECTIVE: To evaluate surgical outcomes after PVCSO in adults with TCS caused by lipomyelomeningocele, who had undergone a previous detethering procedure(s) that ultimately failed.METHODS: This is a multicenter, retrospective analysis of a prospectively collected cohort. Patients were prospectively enrolled and treated with PVCSO at 2 institutions between January 1, 2011 and December 31, 2018. Inclusion criteria were age ≥18yr, TCS caused by lipomyelomeningocele, previous detethering surgery, and recurrent symptom progression of less than 2-yr duration. All patients undergoing surgery with a 1-yr minimum follow-up were evaluated.RESULTS: A total of 20 patients (mean age: 36yr; sex: 15F/5M) met inclusion criteria and were evaluated. At follow-up (mean: 23.3±7.4mo), symptomatic improvement/resolution was seen in 93% of patients with leg pain, 84% in back pain, 80% in sensory abnormalities, 80% in motor deficits, 55% in bowel incontinence, and 50% in urinary incontinence. Oswestry Disability Index improved from a preoperative mean of 57.7 to 36.6 at last follow-up (P<.01). Mean spinal column height reduction was 23.4±2.7mm. Four complications occurred: intraoperative durotomy (no reoperation), wound infection, instrumentation failure requiring revision, and new sensory abnormality.CONCLUSION: This is the largest study to date assessing the safety and efficacy of PVCSO in adults with TCS caused by lipomyelomeningocele and prior failed detethering. We found PVCSO to be an excellent extradural approach that may afford definitive treatment in this particularly challenging population.

    View details for DOI 10.1093/neuros/nyaa491

    View details for PubMedID 33372221

  • Experience with an Enhanced Recovery After Spine Surgery protocol at an academic community hospital. Journal of neurosurgery. Spine Young, R., Cottrill, E., Pennington, Z., Ehresman, J., Ahmed, A. K., Kim, T., Jiang, B., Lubelski, D., Zhu, A. M., Wright, K. S., Gavin, D., Russo, A., Hanna, M. N., Bydon, A., Witham, T. F., Zygourakis, C., Theodore, N. 2020: 1–8


    OBJECTIVE: Enhanced Recovery After Surgery (ERAS) protocols have rapidly gained popularity in multiple surgical specialties and are recognized for their potential to improve patient outcomes and decrease hospitalization costs. However, they have only recently been applied to spinal surgery. The goal in the present work was to describe the development, implementation, and impact of an Enhanced Recovery After Spine Surgery (ERASS) protocol for patients undergoing elective spine procedures at an academic community hospital.METHODS: A multidisciplinary team, drawing on prior publications and spine surgery best practices, collaborated to develop an ERASS protocol. Patients undergoing elective cervical or lumbar procedures were prospectively enrolled at a single tertiary care center; interventions were standardized across the cohort for pre-, intra-, and postoperative care using standardized order sets in the electronic medical record. Protocol efficacy was evaluated by comparing enrolled patients to a historic cohort of age- and procedure-matched controls. The primary study outcomes were quantity of opiate use in morphine milligram equivalents (MMEs) on postoperative day (POD) 1 and length of stay. Secondary outcomes included frequency and duration of indwelling urinary catheter use, discharge disposition, 30-day readmission and reoperation rates, and complication rates. Multivariable linear regression was used to determine whether ERASS protocol use was independently predictive of opiate use on POD 1.RESULTS: In total, 97 patients were included in the study cohort and were compared with a historic cohort of 146 patients. The patients in the ERASS group had lower POD 1 opiate use than the control group (26 ± 33 vs 42 ± 40 MMEs, p < 0.001), driven largely by differences in opiate-naive patients (16 ± 21 vs 38 ± 36 MMEs, p < 0.001). Additionally, patients in the ERASS group had shorter hospitalizations than patients in the control group (51 ± 30 vs 62 ± 49 hours, p = 0.047). On multivariable regression, implementation of the ERASS protocol was independently predictive of lower POD 1 opiate consumption (beta = -7.32, p < 0.001). There were no significant differences in any of the secondary outcomes.CONCLUSIONS: The authors found that the development and implementation of a comprehensive ERASS protocol led to a modest reduction in postoperative opiate consumption and hospital length of stay in patients undergoing elective cervical or lumbar procedures. As suggested by these results and those of other groups, the implementation of ERASS protocols may reduce care costs and improve patient outcomes after spine surgery.

    View details for DOI 10.3171/2020.7.SPINE20358

    View details for PubMedID 33361481

  • Commentary: Predicting Postoperative Outcomes in Brain Tumor Patients With a 5-Factor Modified Frailty Index. Neurosurgery Zhang, M., Hayden Gephart, M., Zygourakis, C. C. 2020

    View details for DOI 10.1093/neuros/nyaa407

    View details for PubMedID 32888308

  • Leptomeningeal spread with spinal involvement of pineal glioblastoma at initial presentation: A case report INTERDISCIPLINARY NEUROSURGERY-ADVANCED TECHNIQUES AND CASE MANAGEMENT Yerneni, K., Fatemi, P., Vogel, H., Li, G., Zygourakis, C. C. 2020; 21
  • Objective activity tracking in spine surgery: a prospective feasibility study with a low-cost consumer grade wearable accelerometer. Scientific reports Stienen, M. N., Rezaii, P. G., Ho, A. L., Veeravagu, A., Zygourakis, C. C., Tomkins-Lane, C., Park, J., Ratliff, J. K., Desai, A. M. 2020; 10 (1): 4939


    Patient-reported outcome measures (PROMs) are commonly used to estimate disability of patients with spinal degenerative disease. Emerging technological advances present an opportunity to provide objective measurements of activity. In a prospective, observational study we utilized a low-cost consumer grade wearable accelerometer (LCA) to determine patient activity (steps per day) preoperatively (baseline) and up to one year (Y1) after cervical and lumbar spine surgery. We studied 30 patients (46.7% male; mean age 57 years; 70% Caucasian) with a baseline activity level of 5624 steps per day. The activity level decreased by 71% in the 1st postoperative week (p<0.001) and remained 37% lower in the 2nd (p<0.001) and 23% lower in the 4th week (p=0.015). At no time point until Y1 did patients increase their activity level, compared to baseline. Activity was greater in patients with cervical, as compared to patients with lumbar spine disease. Age, sex, ethnic group, anesthesia risk score and fusion were variables associated with activity. There was no correlation between activity and PROMs, but a strong correlation with depression. Determining activity using LCAs provides real-time and longitudinal information about patient mobility and return of function. Recovery took place over the first eight postoperative weeks, with subtle improvement afterwards.

    View details for DOI 10.1038/s41598-020-61893-4

    View details for PubMedID 32188895

  • Robot-Assisted versus Freehand Instrumentation in Short-Segment Lumbar Fusion: Experience with Real-Time, Image-Guided Spinal Robot. World neurosurgery Jiang, B. n., Pennington, Z. n., Azad, T. n., Liu, A. n., Ahmed, A. K., Zygourakis, C. C., Westbroek, E. M., Zhu, A. n., Cottrill, E. n., Theodore, N. n. 2020


    Rising patient demand for minimally invasive surgery and increased payer emphasis on quality-based payment schema have created a need for technologies that provide consistent, high-quality outcomes for patients undergoing spine surgery. Robotic assistance is one such technology. Here we report our early experience with a novel real-time, image-guided robot system for use in short-segment lumbar fusion in patients diagnosed with degenerative disease.A consecutive series of patients undergoing robot-assisted 1- or 2-level lumbar fusion procedures were compared to matched controls who underwent free-hand surgery. Screw accuracy, intraoperative outcomes, and 30-day outcomes were compared.We identified 56 patients who underwent 1- or 2-level lumbar fusion during the study period: 28 who underwent robot-assisted procedures and 28 matched controls who underwent freehand instrumentation placement. No significant differences were found between the robot-assisted surgery cohort and the freehand surgery cohort with respect to matched variables. Patients who underwent robot-assisted surgery had less intraoperative blood loss (266.1±236.8 vs. 598.8±360.2mL; p < 0.001) and shorter hospitalizations (3.5±1.8 vs. 4.5±2.0d; p = 0.01). No differences were noted in complication rates, 30-day outcomes or screw accuracy. Profiling of our initial series revealed an average reduction in operation duration of 4.6 minutes with each additional case.Patients undergoing robot-assisted fusion experienced less intraoperative blood loss and shorter hospitalizations. The results of this initial experience suggest that an image-guided robotic system may provide similar short-term outcomes compared with freehand instrumentation placement.

    View details for DOI 10.1016/j.wneu.2020.01.119

    View details for PubMedID 32001398

  • Simultaneous Coccidioidomycosis and Phaeohyphomycosis in a Kidney Transplant Recipient: A Case Report and Literature Review. Transplant infectious disease : an official journal of the Transplantation Society Puing, A. G., Couture-Cossette, A. n., Wang, A. X., Zygourakis, C. C., Cheng, X. n., Stevens, B. A., Banaei, N. n., Novoa, R. A., Ho, D. Y., Subramanian, A. n. 2020: e13365


    Advances in solid organ transplantation have improved the survival of end-stage organ disease at the expense of an increased risk for opportunistic infections. Unusual clinical presentations and the possibility of concurrent infections make diagnosing invasive fungal infection (IFI) more difficult. Here we present a case of simultaneous vertebral infection caused by Coccidioides immitis-posadasii and subcutaneous phaeohyphomycosis due to Nigrograna mackinnonii in a kidney transplant recipient. The diagnosis of both infections required invasive procedures to obtain tissue and a high index of suspicion that more than one IFI could be present. A multidisciplinary team approach for the management of immunocompromised patients with suspected or diagnosed IFI is warranted.

    View details for DOI 10.1111/tid.13365

    View details for PubMedID 32533741

  • Systematic Review of Cost-Effectiveness Analyses in US Spine Surgery. World neurosurgery Chang, D. n., Zygourakis, C. C., Wadhwa, H. n., Kahn, J. G. 2020

    View details for DOI 10.1016/j.wneu.2020.05.123

    View details for PubMedID 32446983

  • Automatic analysis of global spinal alignment from simple annotation of vertebral bodies. Journal of medical imaging (Bellingham, Wash.) Doerr, S. A., De Silva, T. n., Vijayan, R. n., Han, R. n., Uneri, A. n., Ketcha, M. D., Zhang, X. n., Khanna, N. n., Westbroek, E. n., Jiang, B. n., Zygourakis, C. n., Aygun, N. n., Theodore, N. n., Siewerdsen, J. H. 2020; 7 (3): 035001


    Purpose: Measurement of global spinal alignment (GSA) is an important aspect of diagnosis and treatment evaluation for spinal deformity but is subject to a high level of inter-reader variability. Approach: Two methods for automatic GSA measurement are proposed to mitigate such variability and reduce the burden of manual measurements. Both approaches use vertebral labels in spine computed tomography (CT) as input: the first (EndSeg) segments vertebral endplates using input labels as seed points; and the second (SpNorm) computes a two-dimensional curvilinear fit to the input labels. Studies were performed to characterize the performance of EndSeg and SpNorm in comparison to manual GSA measurement by five clinicians, including measurements of proximal thoracic kyphosis, main thoracic kyphosis, and lumbar lordosis. Results: For the automatic methods, 93.8% of endplate angle estimates were within the inter-reader 95% confidence interval ( CI 95 ). All GSA measurements for the automatic methods were within the inter-reader CI 95 , and there was no statistically significant difference between automatic and manual methods. The SpNorm method appears particularly robust as it operates without segmentation. Conclusions: Such methods could improve the reproducibility and reliability of GSA measurements and are potentially suitable to applications in large datasets-e.g., for outcome assessment in surgical data science.

    View details for DOI 10.1117/1.JMI.7.3.035001

    View details for PubMedID 32411814

    View details for PubMedCentralID PMC7218103

  • Does double-blind peer review impact gender authorship trends? An evaluation of two leading neurosurgical journals from 2010 to 2019. Journal of neurosurgery Mahajan, U. V., Wadhwa, H. n., Fatemi, P. n., Xu, S. n., Shan, J. n., Benzil, D. L., Zygourakis, C. C. 2020: 1–9


    Publications are key for advancement within academia. Although women are underrepresented in academic neurosurgery, the rates of women entering residency, achieving board certification, and publishing papers are increasing. The goal of this study was to assess the current status of women in academic neurosurgery publications. Specifically, this study sought to 1) survey female authorship rates in the Journal of Neurosurgery (JNS [not including JNS: Spine or JNS: Pediatrics]) and Neurosurgery from 2010 to 2019; 2) analyze whether double-blind peer review (started in Neurosurgery in 2011) altered female authorship rates relative to single-blind review (JNS); and 3) evaluate how female authorship rates compared with the number of women entering neurosurgery residency and obtaining neurosurgery board certification.Genders of the first and last authors for JNS and Neurosurgery articles from 2010 to 2019 were obtained. Data were also gathered on the number and percentage of women entering neurosurgery residency and women obtaining American Board of Neurological Surgeons (ABNS) certification between 2010 and 2019.Women accounted for 13.4% (n = 570) of first authors and 6.8% (n = 240) of last authors in JNS and Neurosurgery publications. No difference in rates of women publishing existed between the two journals (first authors: 13.0% JNS vs 13.9% Neurosurgery, p = 0.29; last authors: 7.3% JNS vs 6.0% Neurosurgery, p = 0.25). No difference existed between women first or last authors in Neurosurgery before and after initiation of double-blind review (p = 0.066). Significant concordance existed between the gender of first and last authors: in publications with a woman last author, the odds of the first author being a woman was increased by twofold (OR 2.14 [95% CI 1.43-3.13], p = 0.0001). Women represented a lower proportion of authors of invited papers (8.6% of first authors and 3.1% of last authors were women) compared with noninvited papers (14.1% of first authors and 7.4% of last authors were women) (first authors: OR 0.576 [95% CI 0.410-0.794], p = 0.0004; last authors: OR 0.407 [95% CI 0.198-0.751], p = 0.001). The proportion of women US last authors (7.4%) mirrors the percentage of board-certified women neurosurgeons (5.4% in 2010 and 6.8% in 2019), while the percentage of women US first authors (14.3%) is less than that for women entering neurosurgical residency (11.2% in 2009 and 23.6% in 2018).This is the first report of female authorship in the neurosurgical literature. The authors found that single- versus double-blind peer review did not impact female authorship rates at two top neurosurgical journals.

    View details for DOI 10.3171/2020.6.JNS20902

    View details for PubMedID 33186905

  • Association between Physician Industry Payments and Cost of Anterior Cervical Discectomy and Fusion in Medicare Beneficiaries. World neurosurgery Liu, C. n., Ahmed, K. n., Chen, C. L., Dudley, R. A., Gonzales, R. n., Orrico, K. n., Yerneni, K. n., Stienen, M. N., Veeravagu, A. n., Desai, A. n., Park, J. n., Ratliff, J. K., Zygourakis, C. C. 2020


    Neurosurgical spine specialists receive considerable amounts of industry support which may impact the cost of care. The aim of this study was to evaluate the association between industry payments received by spine surgeons and the total hospital and operating room (OR) costs of an anterior cervical discectomy and fusion (ACDF) procedure among Medicare beneficiaries.All ACDF cases were identified among the Medicare Carrier Files, from January 1, 2013, to December 31, 2014, and matched to the Medicare Inpatient Baseline File. The total hospital and OR charges were obtained for these cases. Charges were converted to cost using year-specific cost-to-charge ratios. Surgeons were identified among Open Payments database, which is used to quantify industry support. Analyses was performed to examine the association between industry payments received and ACDF costs.Matching resulting in the inclusion of 2,209 ACDF claims from 2013-2014. In 2013 and 2014, the mean total cost for an ACDF was $21,798 and $21,008, respectively; mean OR cost was $5,878 and $6,064, respectively. Mann-Whitney U test demonstrated no significant differences in the mean total or OR cost for an ACDF based on quartile of general industry payment received (p=0.21 and p=0.54), and linear regression found no association between industry general payments, research support, or investments on the total hospital cost (p=0.41, p=0.13, and p=0.25), or OR cost for an ACDF (p=0.35, p=0.24, and p=0.40).This study suggests that spine surgeons performing ACDF surgeries may receive industry support without impacting the cost of care.

    View details for DOI 10.1016/j.wneu.2020.08.023

    View details for PubMedID 32791230

  • Tenosynovial giant cell tumor of the suboccipital region - A rare, benign neoplasm in this location. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Singh, R. n., Stienen, M. N., Ganjoo, K. n., Kolahi, K. S., Cayrol, R. n., Charville, G. W., Born, D. E., Zygourakis, C. C. 2020


    Tenosynovial giant cell tumors (TGCTs) are benign neoplasms that arise from the synovium of tendon sheaths, bursae, and joints. We report a rare presentation of TGCT involving the suboccipital spine.

    View details for DOI 10.1016/j.jocn.2020.05.022

    View details for PubMedID 32631721

  • Digital transformation in spine research and outcome assessment. The spine journal : official journal of the North American Spine Society Maldaner, N. n., Tomkins-Lane, C. n., Desai, A. n., Zygourakis, C. C., Weyerbrock, A. n., Gautschi, O. P., Stienen, M. N. 2020; 20 (2): 310–11

    View details for DOI 10.1016/j.spinee.2019.06.027

    View details for PubMedID 32000961

  • The Effect of Renin-angiotensin System Blockers on Spinal Cord Dysfunction and Imaging Features of Spinal Cord Compression in Patients with Symptomatic Cervical Spondylosis. The spine journal : official journal of the North American Spine Society Perdomo-Pantoja, A., Chara, A., Kalb, S., Casaos, J., Ahmed, A., Pennington, Z., Cottrill, E., Shah, S., Jiang, B., Manbachi, A., Zygourakis, C., Witham, T. F., Theodore, N. 2019


    BACKGROUND CONTEXT: Cervical spondylosis may lead to spinal cord compression, poor vascular perfusion, and ultimately, cervical myelopathy. Studies suggest a neuroprotective effect of renin-angiotensin system (RAS) inhibitors in the brain, but limited data exist regarding their impact on the spinal cord.PURPOSE: To investigate whether RAS blockers and other antihypertensive drugs are correlated with preoperative functional status and imaging markers of cord compression in patients with symptomatic cervical spondylosis.STUDY DESIGN: Retrospective observational study.PATIENT SAMPLE: Individuals with symptomatic degenerative cervical stenosis who underwent surgery.OUTCOME MEASURES: Imaging features of spinal cord compression and functional status (modified Japanese Orthopedic Association [mJOA] and Nurick grading scales).METHODS: 266 operative patients with symptomatic degenerative cervical stenosis were included. Demographic data, comorbidities, antihypertensive medications, and functional status (including mJOA and Nurick grading scales) were collected. We evaluated canal compromise, cord compromise, surface area of T2 signal cord change, and pixel intensity of signal cord change compared to normal cord on T2-weighted magnetic resonance imaging sequences.RESULTS: Of 266 patients, 41.7% were women, 58.3% were men; median age was 57.2 years; 20.6% smoked tobacco; 24.7% had diabetes mellitus. 149 patients (55.8%) had hypertension, 142 (95.3%) of these were taking anti-hypertensive medications (37 angiotensin-II receptor blockers [ARBs], 44 angiotensin-converting enzyme inhibitors, and 61 other medications). Patients treated with ARBs displayed a higher signal intensity ratio (ie, less signal intensity change in the compressed cord area) compared to untreated patients without hypertension (p=0.004). Patients with hypertension had worse preoperative mJOA and Nurick scores than those without (p<0.001). In the multivariate analysis, ARBs remained an independent beneficial factor for lower signal intensity change (p=0.04), while hypertension remained a risk factor for worse preoperative neurological status (p<0.01).CONCLUSIONS: In our study, patients with hypertension who were treated with RAS inhibitors had decreased T2-weighted signal intensity change than untreated patients without hypertension. Patients with hypertension also had worse preoperative functional status. Prospective case-control studies may deepen understanding of RAS modulators in the imaging and functional status of chronic spinal cord compression.

    View details for DOI 10.1016/j.spinee.2019.12.002

    View details for PubMedID 31821888

  • Assessment of a triage protocol for emergent neurosurgical cases at a single institution. World neurosurgery Ehresman, J., Ahmed, A. K., Lubelski, D., Pennington, Z., Jiang, B., Zygourakis, C., Cottrill, E., Theodore, N. 2019


    OBJECTIVE: Level I trauma centers use patient triaging systems to deploy neurosurgical resources and pursue good outcomes; however, data describing the effectiveness these triage systems are lacking. We reviewed the leveling protocol (cases designated urgent/emergent) of a regional Level I trauma center to obtain epidemiological data about the efficiency of that system and identify areas for improvement.METHODS: We retrospectively reviewed leveled neurosurgical cases from January 2015-October 2017, assessing surgery date, neurosurgical procedure, posted surgical urgency level (Levels 1-3, with 1 being most urgent), and "post-to-room time" (ie, the time between initial leveling and admission of the patient to the operating room). Mean post-to-room times were compared between case types using one-way ANOVA with post-hoc Tukey's HSD analysis.RESULTS: Of 1,469 cases, 577 (39.3%) were shunt placement/revision, 231 (15.7%) were craniectomy or craniotomy for hematoma, 147 (10.0%) were craniectomy or craniotomy for tumor, and 514 (35.0%) were for other indications. Among Level 1 cases, post-to-room time was lowest for craniotomies to evacuate intracranial hematoma (mean:16.2 minutes) and highest for spinal decompression procedures and wound washouts (mean: 36.2 and 42.4 minutes).CONCLUSION: This is the first study of variability in post-to-room timing as a function of surgical urgency/indication. The most common leveled cases were craniectomies or craniotomies to relieve increased intracranial pressure, which were also the most common Level 1 cases. Significant variability occurred within each leveling category; thus, further investigation is required.

    View details for DOI 10.1016/j.wneu.2019.12.005

    View details for PubMedID 31821911

  • Timing of Adjuvant Radiation Therapy and Risk of Wound-Related Complications Among Patients With Spinal Metastatic Disease. Global spine journal Azad, T. D., Varshneya, K., Herrick, D. B., Pendharkar, A. V., Ho, A. L., Stienen, M., Zygourakis, C., Bagshaw, H. P., Veeravagu, A., Ratliff, J. K., Desai, A. 2019: 2192568219889363


    This was an epidemiological study using national administrative data from the MarketScan database.To investigate the impact of early versus delayed adjuvant radiotherapy (RT) on wound healing following surgical resection for spinal metastatic disease.We queried the MarketScan database (2007-2016), identifying patients with a diagnosis of spinal metastasis who also underwent RT within 8 weeks of surgery. Patients were categorized into "Early RT" if they received RT within 4 weeks of surgery and as "Late RT" if they received RT between 4 and 8 weeks after surgery. Descriptive statistics and hypothesis testing were used to compare baseline characteristics and wound complication outcomes.A total of 540 patients met the inclusion criteria: 307 (56.9%) received RT within 4 weeks (Early RT) and 233 (43.1%) received RT within 4 to 8 weeks (Late RT) of surgery. Mean days to RT for the Early RT cohort was 18.5 (SD, 6.9) and 39.7 (SD, 7.6) for the Late RT cohort. In a 90-day surveillance period, n = 9 (2.9%) of Early RT and n = 8 (3.4%) of Late RT patients developed wound complications (P = .574).When comparing patients who received RT early versus delayed following surgery, there were no significant differences in the rates of wound complications. Further prospective studies should aim to identify optimal patient criteria for early postoperative RT for spinal metastases.

    View details for DOI 10.1177/2192568219889363

    View details for PubMedID 32875859

  • Timing of Adjuvant Radiation Therapy and Risk of Wound-Related Complications Among Patients With Spinal Metastatic Disease GLOBAL SPINE JOURNAL Azad, T. D., Varshneya, K., Herrick, D. B., Pendharkar, A., Ho, A. L., Stienen, M., Zygourakis, C., Bagshaw, H. P., Veeravagu, A., Ratliff, J. K., Desai, A. 2019
  • Known-component 3D image reconstruction for improved intraoperative imaging in spine surgery: A clinical pilot study. Medical physics Zhang, X., Uneri, A., Webster Stayman, J., Zygourakis, C. C., Lo, S. L., Theodore, N., Siewerdsen, J. H. 2019


    PURPOSE: Intraoperative imaging plays an increased role in support of surgical guidance and quality assurance for interventional approaches. However, image quality sufficient to detect complications and provide quantitative assessment of the surgical product is often confounded by image noise and artifacts. In this work, we translated a 3D model-based image reconstruction (referred to as "Known-Component Reconstruction," KC-Recon) for the first time to clinical studies with the aim of resolving both limitations.METHODS: KC-Recon builds upon a penalized weighted least-squares (PWLS) method by incorporating models of surgical instrumentation ("known components") within a joint image registration-reconstruction process to improve image quality. Under IRB approval, a clinical pilot study was conducted with 17 spine surgery patients imaged under informed consent using the O-arm cone-beam CT system (Medtronic, Littleton MA) before and after spinal instrumentation. Volumetric images were generated for each patient using KC-Recon in comparison to conventional filtered back-projection (FBP). Imaging performance prior to instrumentation ("pre-instrumentation") was evaluated in terms of soft-tissue contrast-to-noise ratio (CNR) and spatial resolution. The quality of images obtained after the instrumentation ("post-instrumentation") was assessed by quantifying the magnitude of metal artifacts (blooming and streaks) arising from pedicle screws. The potential low-dose advantages of the algorithm were tested by simulating low-dose data (down to 1 /10 the dose of standard protocols) from images acquired at normal dose.RESULTS: Pre-instrumentation images (at normal clinical dose and at matched resolution) exhibited an average 24.0% increase in soft-tissue CNR with KC-Recon compared to FBP (N = 16, p = 0.02), improving visualization of paraspinal muscles, major vessels, and other soft-tissues about the spine and abdomen. For a total of 72 screws in post-instrumentation images, KC-Recon yielded a significant reduction of metal artifacts: 66.3% reduction in overestimation of screw shaft width due to blooming (p < 0.0001) and reduction of streaks at the screw tip (65.8% increase in attenuation accuracy, p < 0.0001), enabling clearer depiction of the screw within the pedicle and vertebral body for assessment of breach. Depending on the imaging task, dose reduction up to an order of magnitude appeared feasible while maintaining soft-tissue visibility and metal artifact reduction.CONCLUSIONS: KC-Recon offers a promising means to improve visualization in the presence of surgical instrumentation and reduce patient dose in image-guided procedures. The improved soft-tissue visibility could facilitate the use of cone-beam CT to soft-tissue surgeries, and the ability to precisely quantify and visualize instrument placement could provide a valuable check against complications in the operating room (cf., post-operative CT). This article is protected by copyright. All rights reserved.

    View details for DOI 10.1002/mp.13652

    View details for PubMedID 31180586

  • Accuracy of Current Techniques for Placement of Pedicle Screws in the Spine: A Comprehensive Systematic Review and Meta-Analysis of 51,161 Screws WORLD NEUROSURGERY Perdomo-Pantoja, A., Ishida, W., Zygourakis, C., Holmes, C., Iyer, R. R., Cottrill, E., Theodore, N., Witham, T. F., Lo, S. L. 2019; 126: 664-+
  • Estimating a price point for cost-benefit of bone morphogenetic protein in pseudarthrosis prevention for adult spinal deformity surgery JOURNAL OF NEUROSURGERY-SPINE Safaee, M. M., Dalle Ore, C. L., Zygourakis, C. C., Deviren, V., Ames, C. P. 2019; 30 (6): 814–21
  • Accuracy of Current Techniques for Placement of Pedicle Screws in the Spine: A Comprehensive Systematic Review and Meta-Analysis of 51,161 Screws. World neurosurgery Perdomo-Pantoja, A., Ishida, W., Zygourakis, C., Holmes, C., Iyer, R. R., Cottrill, E., Theodore, N., Witham, T. F., Lo, S. L. 2019


    BACKGROUND: Pedicle screws (PS) are routinely used for stabilization to enhance fusion in a variety of spinal pathologies. Although the accuracy of different PS placement methods has been previously reported, the majority of these studies have been limited to one or two techniques.OBJECTIVE: To determine the current accuracy of PS placement among four modalities of PS insertion [free-hand (FH), fluoroscopy-assisted (FA), CT-navigation guided (CTNav), and robot-assisted (RA)] and analyze variables associated with screw misplacement.METHODS: A systematic review of peer-reviewed articles reporting PS accuracy of one technique from January 1990 to June 2018 was performed. Accuracy of PS placement, PS insertion technique, and pedicle breach (PB) data were collected. A meta-analysis was performed to estimate the overall pooled (OP) rates of PS accuracy as a primary outcome, stratified by screw insertion techniques. Potential determinants were analyzed via meta-regression analyses.RESULTS: 78 studies with 7,858 patients, 51,161 PSs, and 3,614 cortical PBs were included. CTNav displayed the highest PS placement accuracy compared to other techniques: OP accuracy rates were 95.5%, 93.1%, 91.5% and 90.5%, via CTNav, FH, FA and RA techniques, respectively. RA and CTNav were associated with the highest PS accuracy in the thoracic spine, compared to FH.CONCLUSIONS: The OP data show that CTNav has the highest PS accuracy rates. Thoracic PSs were associated with lower accuracy rates; however, RA exhibited fewer breaches in the thoracic spine compared to FH and FA. Given the heterogeneity among studies, further standardized and comparative investigations are required to confirm our findings.

    View details for PubMedID 30880208

  • Estimating a price point for cost-benefit of bone morphogenetic protein in pseudarthrosis prevention for adult spinal deformity surgery. Journal of neurosurgery. Spine Safaee, M. M., Dalle Ore, C. L., Zygourakis, C. C., Deviren, V., Ames, C. P. 2019: 1–8


    OBJECTIVEBone morphogenetic protein (BMP) is associated with reduced rates of pseudarthrosis and has the potential to decrease the need for revision surgery. There are limited data evaluating the cost-benefit of BMP for pseudarthrosis-related prevention surgery in adult spinal deformity.METHODSThe authors performed a single-center retrospective review of 200 consecutive patients with adult spinal deformity. Demographic data and costs of BMP, primary surgery, and revision surgery for pseudarthrosis were collected. Patients with less than 12 months of follow-up or with infection, tumor, or neuromuscular disease were excluded.RESULTSOne hundred fifty-one patients (107 [71%] women) with a mean age of 65 years met the inclusion criteria. The mean number of levels fused was 10; BMP was used in 98 cases (65%), and the mean follow-up was 23 months. Fifteen patients (10%) underwent surgical revision for pseudarthrosis; BMP use was associated with an 11% absolute risk reduction in the rate of reoperation (17% vs 6%, p = 0.033), with a number needed to treat of 9.2. There were no significant differences in age, sex, upper instrumented vertebra, or number of levels fused in patients who received BMP. In a multivariate model including age, sex, number of levels fused, and the upper instrumented vertebra, only BMP (OR 0.250, 95% CI 0.078-0.797; p = 0.019) was associated with revision surgery for pseudarthrosis. The mean direct cost of primary surgery was $87,653 ± $19,879, and the mean direct cost of BMP was $10,444 ± $4607. The mean direct cost of revision surgery was $52,153 ± $26,985. The authors independently varied the efficacy of BMP, cost of BMP, and cost of reoperation by ± 50%; only reductions in the cost of BMP resulted in a cost savings per 100 patients. Using these data, the authors estimated a price point of $5663 in order for BMP to be cost-neutral.CONCLUSIONSUse of BMP was associated with a significant reduction in the rates of revision surgery for pseudarthrosis. At its current price, the direct in-hospital costs for BMP exceed the costs associated with revision surgery; however, this likely underestimates the true value of BMP when considering the savings associated with reductions in rehabilitation, therapy, medication, and additional outpatient costs.

    View details for PubMedID 30849745

  • Protocol for Urgent and Emergent Cases at a Large Academic Level 1 Trauma Center. Cureus Ahmed, K., Zygourakis, C., Kalb, S., Pennington, Z., Molina, C., Emerson, T., Theodore, N. 2019; 11 (1): e3973


    Background Level 1 trauma centers are capable of caring for every aspect of injury and contain 24-hour in-house coverage by general surgeons, with prompt availability of nearly all other disciplines upon request. Despite the wide variety of trauma, currently reported protocols often focus on a single surgical service and studies describing their implementation are lacking. The aim of the current study was to characterize all urgent and emergent cases at a large academic Level 1 trauma center, characterize the specialty and nature of emergent operative cases, and assess the efficacy of the institutional trauma protocol on timing of surgery. Methods For this retrospective review, all urgent and emergent cases treated at a single institution, during a 34-month period (January 1, 2015-October 31, 2017), were identified. All included cases were subject to the Institutional Guidelines for Operative Urgent/Emergent Cases. Demographic characteristics for non-elective surgical emergent cases were compiled by level of urgency and operating room (OR) waiting times were compared by year, department, and Level. Results A total of 11,206 urgent and emergent operative cases were included, among over 16 surgical departments. Level 2 cases represented the majority of urgent/emergent cases (33%-36%), followed by Level 3 (25%-26%), Level 1 (21%-22%), Level 4 (12%-16%), and Level 5 (2%-4%). Univariate analysis demonstrated that the proportion of urgent and emergent cases, by level of urgency, did not significantly differ between each year. Operating room waiting time decreased significantly over each year from 2015, 2016, and 2017: 193.40 ± 4.78, 177.20 ± 3.29, and 82.01 ± 2.98 minutes, respectively. Conclusions To the authors' knowledge, this is the first study to characterize all urgent and emergent cases at a large academic Level 1 trauma center, outline the specialty and nature of emergent operative cases, and assess the efficacy of the institutional trauma protocol on surgical waiting times over a 34-month period.

    View details for DOI 10.7759/cureus.3973

    View details for PubMedID 30956925

    View details for PubMedCentralID PMC6438689

  • Protocol for Urgent and Emergent Cases at a Large Academic Level 1 Trauma Center CUREUS Ahmed, K., Zygourakis, C., Kalb, S., Pennington, Z., Molina, C., Emerson, T., Theodore, N. 2019; 11 (1)
  • New spinal robotic technologies. Frontiers of medicine Jiang, B. n., Azad, T. D., Cottrill, E. n., Zygourakis, C. C., Zhu, A. M., Crawford, N. n., Theodore, N. n. 2019


    Robotic systems in surgery have developed rapidly. Installations of the da Vinci Surgical System® (Intuitive Surgical, Sunnyvale, CA, USA), widely used in urological and gynecological procedures, have nearly doubled in the United States from 2010 to 2017. Robotics systems in spine surgery have been adopted more slowly; however, users are enthusiastic about their applications in this subspecialty. Spinal surgery often requires fine manipulation of vital structures that must be accessed via limited surgical corridors and can require repetitive tasks over lengthy periods of time - issues for which robotic assistance is well-positioned to complement human ability. To date, the United States Food and Drug Administration (FDA) has approved 7 robotic systems across 4 companies for use in spinal surgery. The available clinical data evaluating their efficacy have generally demonstrated these systems to be accurate and safe. A critical next step in the broader adoption of surgical robotics in spine surgery is the design and implementation of rigorous comparative studies to interrogate the utility of robotic assistance. Here we discuss current applications of robotics in spine surgery, review robotic systems FDA-approved for use in spine surgery, summarize randomized controlled trials involving robotics in spine surgery, and comment on prospects of robotic-assisted spine surgery.

    View details for DOI 10.1007/s11684-019-0716-6

    View details for PubMedID 31673935

  • First spine surgery utilizing real-time image-guided robotic assistance COMPUTER ASSISTED SURGERY Ahmed, A., Zygourakis, C. C., Kalb, S., Zhu, A. M., Molina, C. A., Jiang, B., Blitz, A. M., Bydon, A., Crawford, N. R., Theodore, N. 2019; 24 (1): 13–17
  • Reliability of the 6-minute walking test smartphone application. Journal of neurosurgery. Spine Stienen, M. N., Gautschi, O. P., Staartjes, V. E., Maldaner, N. n., Sosnova, M. n., Ho, A. L., Veeravagu, A. n., Desai, A. n., Zygourakis, C. C., Park, J. n., Regli, L. n., Ratliff, J. K. 2019: 1–8


    Objective functional measures such as the 6-minute walking test (6WT) are increasingly applied to evaluate patients with degenerative diseases of the lumbar spine before and after (surgical) treatment. However, the traditional 6WT is cumbersome to apply, as it requires specialized in-hospital infrastructure and personnel. The authors set out to compare 6-minute walking distance (6WD) measurements obtained with a newly developed smartphone application (app) and those obtained with the gold-standard distance wheel (DW).The authors developed a free iOS- and Android-based smartphone app that allows patients to measure the 6WD in their home environment using global positioning system (GPS) coordinates. In a laboratory setting, the authors obtained 6WD measurements over a range of smartphone models, testing environments, and walking patterns and speeds. The main outcome was the relative measurement error (rME; in percent of 6WD), with |rME| < 7.5% defined as reliable. The intraclass correlation coefficient (ICC) for agreement between app- and DW-based 6WD was calculated.Measurements (n = 406) were reliable with all smartphone types in neighborhood, nature, and city environments (without high buildings), as well as with unspecified, straight, continuous, and stop-and-go walking patterns (ICC = 0.97, 95% CI 0.97-0.98, p < 0.001). Measurements were unreliable indoors, in city areas with high buildings, and for predominantly rectangular walking courses. Walking speed had an influence on the ME, with worse accuracy (2% higher rME) for every kilometer per hour slower walking pace (95% CI 1.4%-2.5%, p < 0.001). Mathematical adjustment of the app-based 6WD for velocity-dependent error mitigated the rME (p < 0.011), attenuated velocity dependence (p = 0.362), and had a positive effect on accuracy (ICC = 0.98, 95% CI 0.98-0.99, p < 0.001).The new, free, spine-specific 6WT smartphone app measures the 6WD conveniently by using GPS coordinates, empowering patients to independently determine their functional status before and after (surgical) treatment. Measurements of 6WD obtained for the target population under the recommended circumstances are highly reliable.

    View details for DOI 10.3171/2019.6.SPINE19559

    View details for PubMedID 31518975

  • Primum non nocere: robots and spinal surgery. Journal of spine surgery (Hong Kong) Zygourakis, C. C., Theodore, N. 2018; 4 (4): 810–11

    View details for PubMedID 30714015

  • Pedicle screw accuracy assessment in ExcelsiusGPS® robotic spine surgery: evaluation of deviation from pre-planned trajectory. Chinese neurosurgical journal Jiang, B., Karim Ahmed, A., Zygourakis, C. C., Kalb, S., Zhu, A. M., Godzik, J., Molina, C. A., Blitz, A. M., Bydon, A., Crawford, N., Theodore, N. 2018; 4: 23


    The ExcelsiusGPS® (Globus Medical, Inc., Audubon, PA) is a next-generation spine surgery robotic system recently approved for use in the United States. The objective of the current study is to assess pedicle screw accuracy and clinical outcomes among two of the first operative cases utilizing the ExcelsiusGPS® robotic system and describe a novel metric to quantify screw deviation.Two patients who underwent lumbar fusion at a single institution with the ExcelsiusGPS® surgical robot were included. Pre-operative trajectory planning was performed from an intra-operative CT scan using the O-arm (Medtronic, Inc., Minneapolis, MN). After robotic-assisted screw implantation, a post-operative CT scan was obtained to confirm ideal screw placement and accuracy with the planned trajectory. A novel pedicle screw accuracy algorithm was devised to measure screw tip/tail deviation distance and angular offset on axial and sagittal planes. Screw accuracy was concurrently determined by a blinded neuroradiologist using the traditional Gertzbein-Robbins method. Clinical variables such as symptomatology, operative data, and post-operative follow-up were also collected.Eight pedicle screws were placed in two L4-L5 fusion cases. Mean screw tip deviation was 2.1 mm (range 0.8-5.2 mm), mean tail deviation was 3.2 mm (range 0.9-5.4 mm), and mean angular offset was 2.4 degrees (range 0.7-3.8 degrees). All eight screws were accurately placed based on the Gertzbein-Robbins scale (88% Grade A and 12% Grade B). There were no cases of screw revision or new post-operative deficit. Both patients experienced improvement in Frankel grade and Karnofsky Performance Status (KPS) score by 6 weeks post-op.The ExcelsiusGPS® robot allows for precise execution of an intended pre-planned trajectory and accurate screw placement in the first patients to undergo robotic-assisted fusion with this technology.

    View details for DOI 10.1186/s41016-018-0131-x

    View details for PubMedID 32922884

    View details for PubMedCentralID PMC7398380

  • Analysis of National Rates, Cost, and Sources of Cost Variation in Adult Spinal Deformity NEUROSURGERY Zygourakis, C. C., Liu, C. Y., Keefe, M., Moriates, C., Ratliff, J., Dudley, R., Gonzales, R., Mummaneni, P. V., Ames, C. P. 2018; 82 (3): 378–87


    Several studies suggest significant variation in cost for spine surgery, but there has been little research in this area for spinal deformity.To determine the utilization, cost, and factors contributing to cost for spinal deformity surgery.The cohort comprised 55 599 adults who underwent spinal deformity fusion in the 2001 to 2013 National Inpatient Sample database. Patient variables included age, gender, insurance, median income of zip code, county population, severity of illness, mortality risk, number of comorbidities, length of stay, elective vs nonelective case. Hospital variables included bed size, wage index, hospital type (rural, urban nonteaching, urban teaching), and geographical region. The outcome was total hospital cost for deformity surgery. Statistics included univariate and multivariate regression analyses.The number of spinal deformity cases increased from 1803 in 2001 (rate: 4.16 per 100 000 adults) to 6728 in 2013 (rate: 13.9 per 100 000). Utilization of interbody fusion devices increased steadily during this time period, while bone morphogenic protein usage peaked in 2010 and declined thereafter. The mean inflation-adjusted case cost rose from $32 671 to $43 433 over the same time period. Multivariate analyses showed the following patient factors were associated with cost: age, race, insurance, severity of illness, length of stay, and elective admission (P < .01). Hospitals in the western United States and those with higher wage indices or smaller bed sizes were significantly more expensive (P < .05).The rate of adult spinal deformity surgery and the mean case cost increased from 2001 to 2013, exceeding the rate of inflation. Both patient and hospital factors are important contributors to cost variation for spinal deformity surgery.

    View details for PubMedID 28486687

  • Implementation and Impact of a Hospital-Wide Instrument Set Review: Early Experiences at a Multisite Tertiary Care Academic Institution. American journal of medical quality : the official journal of the American College of Medical Quality Yoon, S. n., Zygourakis, C. C., Seaman, J. n., Zhu, M. n., Ahmed, A. K., Kliot, T. n., Antrum, S. n., Goldberg, A. N. 2018: 1062860618783261


    A multidisciplinary team of nurses, sterile processing technicians, and surgeons reviewed 609 otolaryngology-head and neck surgery (OHNS) surgical instrument sets at the study institution's 3 hospitals. Implementation of the 4-phase instrument review resulted in decreased OHNS surgical instrument set types from 261 to 234 sets, and a decreased number of instruments in these sets from 18 952 to 17 084. The instrument set review resulted in an estimated savings of $35 665 in sterile processing costs for the OHNS department. Instrument review applied to all 10 surgical specialties at the institution would result in an estimated annual savings of $425 378. Through effective leadership, multidisciplinary participation of all key stakeholders, and a systematic approach, this study demonstrates that a hospital-wide quality improvement intervention for instrument set optimization can be successfully performed in a large, multisite tertiary care academic hospital.

    View details for PubMedID 29936862

  • Center variation in episode-of-care costs for adult spinal deformity surgery: results from a prospective, multicenter database. The spine journal : official journal of the North American Spine Society Yeramaneni, S. n., Ames, C. P., Bess, S. n., Burton, D. n., Smith, J. S., Glassman, S. n., Gum, J. L., Carreon, L. n., Jain, A. n., Zygourakis, C. n., Avramis, I. n., Hostin, R. n. 2018; 18 (10): 1829–36


    Adult spinal deformity (ASD) surgery is associated with significant resource utilization, costing more than $958 million in charges for Medicare patients and more than $1.7 billion in charges for managed care population in the last decade. Given the recent move toward bundled payment models, it is important to understand the various care components a patient receives over the course of a defined clinical episode, its associated cost, and the proportion of cost for each component toward the bundled payment.To examine the degree and determinants of variation in inpatient episode-of-care (EOC) cost, resource utilization, and patient-reported outcomes for patients undergoing ASD surgery across four spine deformity centers in the United States.Retrospective analysis of prospective, multicenter database.Consecutive patients enrolled in an ASD database from four spinal deformity centers.Total in-patient EOC costs and Short Form (SF)-6D.The study used a multicenter database of 210 consecutively enrolled operative patients from 2008 to 2013 at four participating centers in the United States. Demographic, surgical, and direct cost data, expressed in 2013 dollars, for the entire inpatient EOC were obtained from administrative databases from the respective hospitals. Mixed models and multivariable linear regression were used to evaluate the impact of center on total costs adjusting for patient characteristics, length of stay (LOS), and surgical factors.A total of 126 patients with complete baseline and 2-year follow-up data were included. The percentages of patients from each center were 36.5%, 7.1%, 24.6%, and 31.7%. Overall, the mean patient age was 58.4±12.6 years, 86% were women, and 94% were Caucasian. The proportion of total cost variation explained by the center at which the patient was treated was 17%. After adjusting for patient, LOS, and surgical factors the cost variation reduced to 4%. In multivariable analysis, each additional level fused increased total cost variation by $2,500, whereas recombinant human bone morphogenetic protein-2 (BMP) use and posterior-only surgical approach lowered total EOC costs by $10,500 and $9,400, respectively. No significant difference was observed in 2-year quality-adjusted life year across centers.Total EOC costs for ASD surgery varied significantly by center. Levels fused, BMP use, and surgical approach were the primary drivers of cost variation across centers. Differences in resource utilization had no impact on 2-year quality-adjusted life year improvement across centers.

    View details for PubMedID 29578109

  • The unreimbursed costs of preventing revision surgery in adult spinal deformity: analysis of cost-effectiveness of proximal junctional failure prevention with ligament augmentation. Neurosurgical focus Safaee, M. M., Dalle Ore, C. L., Zygourakis, C. C., Deviren, V. n., Ames, C. P. 2018; 44 (5): E13


    OBJECTIVE Proximal junctional kyphosis (PJK) is a well-recognized complication of surgery for adult spinal deformity and is characterized by increased kyphosis at the upper instrumented vertebra (UIV). PJK prevention strategies have the potential to decrease morbidity and cost by reducing rates of proximal junctional failure (PJF), which the authors define as radiographic PJK plus clinical sequelae requiring revision surgery. METHODS The authors performed an analysis of 195 consecutive patients with adult spinal deformity. Age, sex, levels fused, upper instrumented vertebra (UIV), use of 3-column osteotomy, pelvic fixation, and mean time to follow-up were collected. The authors also reviewed operative reports to assess for the use of surgical adjuncts targeted toward PJK prevention, including ligament augmentation, hook fixation, and vertebroplasty. The cost of surgery, including direct and total costs, was also assessed at index surgery and revision surgery. Only revision surgery for PJF was included. RESULTS The mean age of the cohort was 64 years (range 25-84 years); 135 (69%) patients were female. The mean number of levels fused was 10 (range 2-18) with the UIV as follows: 2 cervical (1%), 73 upper thoracic (37%), 108 lower thoracic (55%), and 12 lumbar (6%). Ligament augmentation was used in 99 cases (51%), hook fixation in 60 cases (31%), and vertebroplasty in 71 cases (36%). PJF occurred in 18 cases (9%). Univariate analysis found that ligament augmentation and hook fixation were associated with decreased rates of PJF. However, in a multivariate model that also incorporated age, sex, and UIV, only ligament augmentation maintained a significant association with PJF reduction (OR 0.196, 95% CI 0.050-0.774; p = 0.020). Patients with ligament augmentation, compared with those without, had a higher cost of index surgery, but ligament augmentation was overall cost effective and produced significant cost savings. In sensitivity analyses in which we independently varied the reduction in PJF, cost of ligament augmentation, and cost of reoperation by ± 50%, ligament augmentation remained a cost-effective strategy for PJF prevention. CONCLUSIONS Prevention strategies for PJK/PJF are limited, and their cost-effectiveness has yet to be established. The authors present the results of 195 patients with adult spinal deformity and show that ligament augmentation is associated with significant reductions in PJF in both univariate and multivariate analyses, and that this intervention is cost-effective. Future studies will need to determine if these clinical results are reproducible, but for high-risk cases, these data suggest an important role of ligament augmentation for PJF prevention and cost savings.

    View details for PubMedID 29712521

  • Immediate improvement of intraoperative monitoring signals following CSF release for cervical spine stenosis: Case report. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Pennington, Z. n., Zygourakis, C. n., Ahmed, A. K., Kalb, S. n., Zhu, A. n., Theodore, N. n. 2018; 53: 235–37


    Cervical spondylotic myelopathy (CSM) is a degenerative pathology characterized by partial or complete conduction block on intraoperative neuromonitoring. We describe a case treated using osseoligamentous decompression and durotomy for cerebrospinal fluid (CSF) release. Intraoperative monitoring demonstrated immediate signal improvement with CSF release, suggesting that clinical improvement in CSM may result from resolution of CSF flow anomalies.

    View details for PubMedID 29716808

  • The Safety and Efficacy of CT-Guided, Fluoroscopy-Free Vertebroplasty in Adult Spinal Deformity Surgery. World neurosurgery Zygourakis, C. C., DiGiorgio, A. M., Crutcher, C. L., Safaee, M. n., Nicholls, F. H., Dalle Ore, C. n., Ahmed, A. K., Deviren, V. n., Ames, C. P. 2018; 116: e944–e950


    The goal of this study is to analyze the safety and efficacy of a novel technique of computed tomography-guided, fluoroscopy-free vertebroplasty as an adjunct to help prevent proximal junction kyphosis (PJK) in long-segment posterior spinal fusions.We performed a retrospective analysis of 118 consecutive patients with adult spinal deformity who underwent long-segment fusion with vertebroplasty augmentation from 2013-2016 at a single institution. For each patient, we collected demographics, surgical information, length of stay, discharge disposition, and complications, including reoperation, PJK, and PJK requiring reoperation. We reviewed all postoperative radiographs to assess for cement leakage from vertebroplasty. These patients were compared to a historical control of 253 patients who underwent adult spinal deformity surgery without vertebroplasty augmentation.The PJK rate of 14% and the PJK requiring reoperation rate of 3% in the cohort of 118 patients who underwent vertebroplasty-augmented fusion was significantly lower than that of the 253 historical controls at our institution who did not undergo vertebroplasty (40% PJK rate, 17% PJK-rate requiring reoperation; both P < 0.001). After controlling for patient and other surgical factors in multivariate analyses, vertebroplasty was significantly associated with lower rates of PJK and PJK requiring reoperation (P < 0.001 and P = 0.003).Our novel vertebroplasty technique is safe, and it eliminates the need for additional fluoroscopy in cases already using the O-arm to verify screw placement. In addition, it is an effective technique for reducing PJK in adult spinal deformity surgery compared with historical institutional controls.

    View details for PubMedID 29857213

  • Analysis of Cost Variation in Craniotomy for Tumor Using 2 National Databases. Neurosurgery Zygourakis, C. C., Liu, C. Y., Yoon, S., Moriates, C., Boscardin, C., Dudley, R. A., Lawton, M. T., Theodosopoulos, P., Berger, M. S., Gonzales, R. 2017; 81 (6): 972-979


    There is a significant increase and large variation in craniotomy costs. However, the causes of cost differences in craniotomies remain poorly understood.To examine the patient and hospital factors that underlie the cost variation in tumor craniotomies using 2 national databases: the National Inpatient Sample (NIS) and Vizient, Inc. (Irving, Texas).For 41 483 patients who underwent primary surgery for supratentorial brain tumors from 2001 to 2013 in the NIS, we created univariate and multivariate models to evaluate the effect of several patient factors and hospital factors on total hospital cost. Similarly, we performed multivariate analysis with 15 087 cases in the Vizient 2012 to 2015 database.In the NIS, the mean inflation-adjusted cost per tumor craniotomy increased 30%, from $23 021 in 2001 to $29 971 in 2013. In 2001, the highest cost region was the Northeast ($24 486 ± $1184), and by 2013 the western United States was the highest cost region ($36 058 ± $1684). Multivariate analyses with NIS data showed that male gender, white race, private insurance, higher mortality risk, higher severity of illness, longer length of stay, elective admissions, higher wage index, urban teaching hospitals, and hospitals in the western United States were associated with higher tumor craniotomy costs (all P < .05). Multivariate analyses with Vizient data confirmed that longer length of stay and the western United States were significantly associated with higher costs (P < .001).After controlling for patient/clinical factors, hospital type, bed size, and wage index, hospitals in the western United States had higher costs than those in other parts of the country, based on analyses from 2 separate national databases.

    View details for DOI 10.1093/neuros/nyx133

    View details for PubMedID 28402457

  • Trends in Utilization and Cost of Cervical Spine Surgery Using the National Inpatient Sample Database, 2001 to 2013 SPINE Liu, C. Y., Zygourakis, C. C., Yoon, S., Kliot, T., Moriates, C., Ratliff, J., Dudley, R., Gonzales, R., Mummaneni, P. V., Ames, C. P. 2017; 42 (15): E906–E913


    A retrospective review.The aim of this study was to determine national rates of cervical spine surgery and to examine factors that underlie cost variation.There has been an increase in the rate and cost of spinal surgery over the past decades, but there is little understanding of the drivers of cost variation at the national level.We analyzed 419,830 patients who underwent cervical spine surgery (anterior cervical fusion, posterior cervical fusion, posterior cervical decompression, combined anterior/posterior cervical fusion) for degenerative conditions in the 2001 to 2013 NIS database. We determined the rates of surgery by time and geographic region, and then created univariate and multivariate models to evaluate the effect of these factors on total hospital costs: patient age, gender, race, insurance, income, county of residence, elective versus nonelective case, length of stay, risk of mortality, severity of illness, hospital bed size, wage index, hospital type, and geographic region.The most common type of cervical spine surgery was anterior fusion (80.6% of all surgeries). The national rates of all cervical spine surgery decreased slightly from 2001 to 2013 (75.34 to 72.20 per 100,000 adults), while the mean inflation-adjusted cost increased 64%, from $11,799 to $19,379, during this time period. Multivariate analyses showed that older age, male gender, black/other race, private insurance, greater risk of mortality/severity of illness, and longer length of stay were associated with higher costs. The wage index was positively correlated with cost, and hospitals in the western U.S. were 27% more expensive than those in the Northeast.The rate of cervical spine surgery decreased slightly, while the mean case cost increased at a rate double that of inflation from 2001 to 2013. Even after controlling for patient and hospital factors including wage index, there was significant geographic variation in the cost for cervical spine surgery.3.

    View details for PubMedID 28562473

  • Geographic and Hospital Variation in Cost of Lumbar Laminectomy and Lumbar Fusion for Degenerative Conditions NEUROSURGERY Zygourakis, C. C., Liu, C. Y., Wakam, G., Moriates, C., Boscardin, C., Ames, C. P., Mummaneni, P. V., Ratliff, J., Dudley, R., Gonzales, R. 2017; 81 (2): 331–40


    Spinal surgery costs vary significantly across hospitals and regions, but there is insufficient understanding of what drives this variation.To examine the factors underlying the cost variation for lumbar laminectomy/discectomy and lumbar fusions.We obtained patient information (age, gender, race, severity of illness, risk of mortality, population of county of residence, median zipcode income, insurance status, elective vs nonelective admission, length of stay) and hospital data (region, hospital type, bed size, wage index) for all patients who underwent lumbar laminectomy/discectomy (n = 181 267) or lumbar fusions (n = 433 364) for degenerative conditions in the 2001 to 2013 National Inpatient Sample database. We performed unadjusted and adjusted analyses to determine which factors affect cost.Mean costs for lumbar laminectomy/discectomy and lumbar fusion increased from $8316 and $21 473 in 2001 (in inflation-adjusted 2013 dollars), to $11 405 and $29 438, respectively, in 2013. There was significant regional variation in cost, with the West being the most expensive region across all years and showing the steepest increase in cost over time. After adjusting for patient and hospital factors, the West was 23% more expensive than the Northeast for lumbar laminectomy/discectomy, and 25% more expensive than the Northeast for lumbar fusion ( P < .01). Higher wage index, smaller hospital bed size, and rural/urban nonteaching hospital type were also associated with higher cost for lumbar laminectomy/discectomy and fusion ( P < .01).After adjusting for patient factors and wage index, the Western region, hospitals with smaller bed sizes, and rural/urban nonteaching hospitals were associated with higher costs for lumbar laminectomy/discectomy and lumbar fusion.

    View details for PubMedID 28327960

  • Cost-Effectiveness Analysis of Surgical versus Medical Treatment of Prolactinomas. Journal of neurological surgery. Part B, Skull base Zygourakis, C. C., Imber, B. S., Chen, R., Han, S. J., Blevins, L., Molinaro, A., Kahn, J. G., Aghi, M. K. 2017; 78 (2): 125-131


    Background Few studies address the cost of treating prolactinomas. We performed a cost-utility analysis of surgical versus medical treatment for prolactinomas. Materials and Methods We determined total hospital costs for surgically and medically treated prolactinoma patients. Decision-tree analysis was performed to determine which treatment produced the highest quality-adjusted life years (QALYs). Outcome data were derived from published studies. Results Average total costs for surgical patients were $19,224 ( ± 18,920). Average cost for the first year of bromocriptine or cabergoline treatment was $3,935 and $6,042, with $2,622 and $4,729 for each additional treatment year. For a patient diagnosed with prolactinoma at 40 years of age, surgery has the lowest lifetime cost ($40,473), followed by bromocriptine ($41,601) and cabergoline ($70,696). Surgery also appears to generate high health state utility and thus more QALYs. In sensitivity analyses, surgery appears to be a cost-effective treatment option for prolactinomas across a range of ages, medical/surgical costs, and medical/surgical response rates, except when surgical cure rates are ≤ 30%. Conclusion Our single institution analysis suggests that surgery may be a more cost-effective treatment for prolactinomas than medical management for a range of patient ages, costs, and response rates. Direct empirical comparison of QALYs for different treatment strategies is needed to confirm these findings.

    View details for DOI 10.1055/s-0036-1592193

    View details for PubMedID 28321375

    View details for PubMedCentralID PMC5357228

  • Operating room waste: disposable supply utilization in neurosurgical procedures. Journal of neurosurgery Zygourakis, C. C., Yoon, S., Valencia, V., Boscardin, C., Moriates, C., Gonzales, R., Lawton, M. T. 2017; 126 (2): 620-625


    OBJECTIVE Disposable supplies constitute a large portion of operating room (OR) costs and are often left over at the end of a surgical case. Despite financial and environmental implications of such waste, there has been little evaluation of OR supply utilization. The goal of this study was to quantify the utilization of disposable supplies and the costs associated with opened but unused items (i.e., "waste") in neurosurgical procedures. METHODS Every disposable supply that was unused at the end of surgery was quantified through direct observation of 58 neurosurgical cases at the University of California, San Francisco, in August 2015. Item costs (in US dollars) were determined from the authors' supply catalog, and statistical analyses were performed. RESULTS Across 58 procedures (36 cranial, 22 spinal), the average cost of unused supplies was $653 (range $89-$3640, median $448, interquartile range $230-$810), or 13.1% of total surgical supply cost. Univariate analyses revealed that case type (cranial versus spinal), case category (vascular, tumor, functional, instrumented, and noninstrumented spine), and surgeon were important predictors of the percentage of unused surgical supply cost. Case length and years of surgical training did not affect the percentage of unused supply cost. Accounting for the different case distribution in the 58 selected cases, the authors estimate approximately $968 of OR waste per case, $242,968 per month, and $2.9 million per year, for their neurosurgical department. CONCLUSIONS This study shows a large variation and significant magnitude of OR waste in neurosurgical procedures. At the authors' institution, they recommend price transparency, education about OR waste to surgeons and nurses, preference card reviews, and clarification of supplies that should be opened versus available as needed to reduce waste.

    View details for DOI 10.3171/2016.2.JNS152442

    View details for PubMedID 27153160

  • Clinical utility and cost analysis of routine postoperative head CT in elective aneurysm clippings. Journal of neurosurgery Zygourakis, C. C., Winkler, E., Pitts, L., Hannegan, L., Franc, B., Lawton, M. T. 2017; 126 (2): 558-563


    OBJECTIVE Postoperative head CT scanning is performed routinely at the authors' institution on all neurosurgical patients after elective aneurysm clippings. The goal of this study was to determine how often these scans influence medical management and to quantify the associated imaging costs. METHODS The authors reviewed the medical records and accounting database of 304 patients who underwent elective (i.e., nonruptured) aneurysm clipping performed by 1 surgeon (M.T.L.) from 2010 to 2014 at the University of California, San Francisco. Specifically, the total number of postoperative head CT scans, radiographic findings, and the effect of these studies on patient management were determined. The authors obtained the total hospital costs for these patients, including the cost of imaging studies, from the hospital accounting database. RESULTS Overall, postoperative CT findings influenced clinical management in 3.6% of cases; specifically, they led to permissive hypertension in 4 patients for possible ischemia, administration of mannitol for edema and high-flow oxygen for pneumocephalus in 2 patients each, seizure prophylaxis in 1 patient, Plavix readjustment in 1 patient, and return to the operating room for an asymptomatic epidural hematoma evacuation in 1 patient. When patients were stratified on the basis of postoperative neurological examination, findings on CT scans altered management in 1.1%, 4.8%, and 9.0% of patients with no new neurological deficits, a nonfocal examination, and focal deficits, respectively. The mean total hospital cost for treating patients who undergo elective aneurysm clipping was $72,227 (± $53,966) (all values are US dollars), and the cost of obtaining a noncontrast head CT scan was $292. Neurologically intact patients required 99 head CT scans, at a cost of $28,908, to obtain 1 head CT scan that influenced medical management. In contrast, patients with a focal neurological deficit required only 11 head CT scans, at a cost of $3212, to obtain 1 head CT scan that changed clinical management. CONCLUSIONS Although there are no clear guidelines, the large number and high cost of CT scans needed to treat neurologically intact elective aneurysm patients suggest that careful neurological monitoring may be more clinically useful and a better use of hospital resources than routine postoperative CT.

    View details for DOI 10.3171/2016.1.JNS152242

    View details for PubMedID 27128595

  • Comparison of Patient Outcomes in 3725 Overlapping vs 3633 Nonoverlapping Neurosurgical Procedures Using a Single Institution's Clinical and Administrative Database. Neurosurgery Zygourakis, C. C., Keefe, M. n., Lee, J. n., Barba, J. n., McDermott, M. W., Mummaneni, P. V., Lawton, M. T. 2017; 80 (2): 257–68


    Overlapping surgery is a common practice to improve surgical efficiency, but there are limited data on its safety.To analyze the patient outcomes of overlapping vs nonoverlapping surgeries performed by multiple neurosurgeons.Retrospective review of 7358 neurosurgical procedures, 2012 to 2015, at an urban academic hospital. Collected variables: patient age, gender, insurance, American Society of Anesthesiologists score, severity of illness, mortality risk, admission type, transfer source, procedure type, surgery date, number of cosurgeons, presence of neurosurgery resident/fellow/another attending, and overlapping vs nonoverlapping surgery. Outcomes: procedure time, length of stay, estimated blood loss, discharge location, 30-day mortality, 30-day readmission, return to operating room, acute respiratory failure, and severe sepsis. Statistics: univariate, then multivariate mixed-effect models.Overlapping surgery patients (n = 3725) were younger and had lower American Society of Anesthesiologists scores, severity of illness, and mortality risk (P < .0001) than nonoverlapping surgery patients (n = 3633). Overlapping surgeries had longer procedure times (214 vs 172 min; P < .0001), but shorter length of stay (7.3 vs 7.9 d; P = .010) and lower estimated blood loss (312 vs 363 mL’s; P = .003). Overlapping surgery patients were more likely to be discharged home (73.6% vs 66.2%; P < .0001), and had lower mortality rates (1.3% vs 2.5%; P = .0005) and acute respiratory failure (1.8% vs 2.6%; P = .021). In multivariate models, there was no significant difference between overlapping and nonoverlapping surgeries for any patient outcomes, except for procedure duration, which was longer in overlapping surgery (estimate = 23.03; P < .001).When planned appropriately, overlapping surgery can be performed safely within the infrastructure at our academic institution.

    View details for PubMedID 28173545

  • Sexual function after cervical spine surgery: Independent predictors of functional impairment. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Keefe, M. K., Zygourakis, C. C., Theologis, A. A., Canepa, E. n., Shaw, J. D., Goldman, L. H., Burch, S. n., Berven, S. n., Chou, D. n., Tay, B. n., Mummaneni, P. n., Deviren, V. n., Ames, C. P. 2017; 36: 94–101


    Sexual function (SF) is an important component of patient-focused health related quality of life (HRQoL), but it has not been well studied in spine surgery. This study aims to assess SF after cervical spine surgery and identify predictors of SF. This single-center retrospective study evaluates SF of adults who underwent cervical spine surgery 2007-2012. Predictor variables included demographics, medical/surgical history, operative information, HRQoL measures (Neck Disability Index, SF-12), validated SF surveys [Female Sexual Function Index (FSFI) and Brief Sexual Function Inventory (BSFI) for males], and a study-specific SF questionnaire. 59 patients (31M, 28F; mean age=56±8.4) had significantly lower SF scores compared to age-matched peers: average BSFI = 2.26±1.22 (vs. 06±0.74), average FSFI=13.05±11.42 (<26.55 indicating sexual dysfunction). In men, lower mental SF-12 and higher NDI, back pain, and number of operated levels were associated with lower BSFI scores (all p<0.05). In women, higher total number of medications and pain medications were associated with lower FSFI scores (both p<0.05). 46% of patients reported difficulty performing a sexual position after surgery that they had previously enjoyed. 39% of men had difficulty on top during intercourse, and 32% of participants reported difficulty performing oral sex. 39% of patients reported worse SF, while only 5% reported an improvement in postoperative SF. Men and women who underwent cervical spine surgery had lower SF scores than age-matched peers, likely attributable to general mental health, regional neck disability, back pain, and medications. A large portion of patients reported subjectively worsened SF after surgery.

    View details for PubMedID 27825608

  • Performing concurrent operations in academic vascular neurosurgery does not affect patient outcomes. Journal of neurosurgery Zygourakis, C. C., Lee, J. n., Barba, J. n., Lobo, E. n., Lawton, M. T. 2017; 127 (5): 1089–95


    OBJECTIVE Concurrent surgeries, also known as "running two rooms" or simultaneous/overlapping operations, have recently come under intense scrutiny. The goal of this study was to evaluate the operative time and outcomes of concurrent versus nonconcurrent vascular neurosurgical procedures. METHODS The authors retrospectively reviewed 1219 procedures performed by 1 vascular neurosurgeon from 2012 to 2015 at the University of California, San Francisco. Data were collected on patient age, sex, severity of illness, risk of mortality, American Society of Anesthesiologists (ASA) status, procedure type, admission type, insurance, transfer source, procedure time, presence of resident or fellow in operating room (OR), number of co-surgeons, estimated blood loss (EBL), concurrent vs nonconcurrent case, severe sepsis, acute respiratory failure, postoperative stroke causing neurological deficit, unplanned return to OR, 30-day mortality, and 30-day unplanned readmission. For aneurysm clipping cases, data were also obtained on intraoperative aneurysm rupture and postoperative residual aneurysm. Chi-square and t-tests were performed to compare concurrent versus nonconcurrent cases, and then mixed-effects models were created to adjust for different procedure types, patient demographics, and clinical indicators between the 2 groups. RESULTS There was a significant difference in procedure type for concurrent (n = 828) versus nonconcurrent (n = 391) cases. Concurrent cases were more likely to be routine/elective admissions (53% vs 35%, p < 0.001) and physician referrals (59% vs 38%, p < 0.001). This difference in patient/case type was also reflected in the lower severity of illness, risk of death, and ASA class in the concurrent versus nonconcurrent cases (p < 0.01). Concurrent cases had significantly longer procedural times (243 vs 213 minutes) and more unplanned 30-day readmissions (5.7% vs 3.1%), but shorter mean length of hospital stay (11.2 vs 13.7 days), higher rates of discharge to home (66% vs 51%), lower 30-day mortality rates (3.1% vs 6.1%), lower rates of acute respiratory failure (4.3% vs 8.2%), and decreased 30-day unplanned returns to the OR (3.3% vs 6.9%; all p < 0.05). Rates of severe sepsis, postoperative stroke, intraoperative aneurysm rupture, and postoperative aneurysm residual were equivalent between the concurrent and nonconcurrent groups (all p values nonsignificant). Mixed-effects models showed that after controlling for procedure type, patient demographics, and clinical indicators, there was no significant difference in acute respiratory failure, severe sepsis, 30-day readmission, postoperative stroke, EBL, length of stay, discharge status, or intraoperative aneurysm rupture between concurrent and nonconcurrent cases. Unplanned return to the OR and 30-day mortality were significantly lower in concurrent cases (odds ratio 0.55, 95% confidence interval 0.31-0.98, p = 0.0431, and odds ratio 0.81, p < 0.001, respectively), but concurrent cases had significantly longer procedure durations (odds ratio 21.73; p < 0.001). CONCLUSIONS Overall, there was a significant difference in the types of concurrent versus nonconcurrent cases, with more routine/elective cases for less sick patients scheduled in an overlapping fashion. After adjusting for patient demographics, procedure type, and clinical indicators, concurrent cases had longer procedure times, but equivalent patient outcomes, as compared with nonconcurrent vascular neurosurgical procedures.

    View details for PubMedID 28106498

  • Comparison of Patient Outcomes and Cost of Overlapping Versus Nonoverlapping Spine Surgery. World neurosurgery Zygourakis, C. C., Sizdahkhani, S. n., Keefe, M. n., Lee, J. n., Chou, D. n., Mummaneni, P. V., Ames, C. P. 2017; 100: 658–64.e8


    Overlapping surgery recently has gained significant media attention, but there are limited data on its safety and efficacy. To date, there has been no analysis of overlapping surgery in the field of spine. Our goal was to compare overlapping versus nonoverlapping spine surgery patient outcomes and cost.A retrospective review was undertaken of 2319 spine surgeries (n = 848 overlapping; 1471 nonoverlapping) performed by 3 neurosurgery attendings from 2012 to 2015 at the University of California San Francisco. Collected variables included patient age, sex, insurance, American Society of Anesthesiology score, severity of illness, risk of mortality, procedure type, surgeon, day of surgery, source of transfer, admission type, overlapping versus nonoverlapping surgery (≥1 minute of overlapping procedure time), Medicare-Severity Diagnosis-Related Group, osteotomy, and presence of another attending/fellow/resident. Univariate, then multivariate mixed-effect models were used to evaluate the effect of the collected variables on the following outcomes: procedure time, estimated blood loss, length of stay, discharge status, 30-day mortality, 30-day unplanned readmission, unplanned return to OR, and total hospital cost.Urgent spine cases were more likely to be done in an overlapping fashion (all P < 0.01). After we adjusted for patient demographics, clinical indicators, and procedure characteristics, overlapping surgeries had longer procedure times (estimate = 26.17; P < 0.001) and lower rates of discharge to home (odds ratio 0.65; P < 0.001), but equivalent rates of 30-day mortality, readmission, return to the operating room, estimated blood loss, length of stay, and total hospital cost (all P = ns).Overlapping spine surgery may be performed safely at our institution, although continued monitoring of patient outcomes is necessary. Overlapping surgery does not lead to greater hospital costs.

    View details for PubMedID 28137549

  • Developing an algorithm for cost-effective, clinically judicious management of peripheral nerve tumors. Surgical neurology international Birk, H., Zygourakis, C. C., Kliot, M. 2016; 7: 80


    Peripheral nerve tumors such as neurofibromas and schwannomas have become increasingly identified secondary to improved imaging modalities including magnetic resonance neurogram and ultrasound. Given that a majority of these peripheral nerve tumors are benign lesions, it becomes important to determine appropriate management of such asymptomatic masses. We propose a normal cost-effective management paradigm for asymptomatic peripheral nerve neurofibromas and schwannomas that has been paired with economic analyses. Specifically, our management paradigm identifies patients who would benefit from surgery for asymptomatic peripheral nerve tumors, while providing cost-effective recommendations regarding clinical exams and serial imaging for such patients.

    View details for DOI 10.4103/2152-7806.189299

    View details for PubMedID 27625890

    View details for PubMedCentralID PMC5009575

  • Economic Impact of Revision Surgery for Proximal Junctional Failure After Adult Spinal Deformity Surgery: A Cost Analysis of 57 Operations in a 10-year Experience at a Major Deformity Center. Spine Theologis, A. A., Miller, L., Callahan, M., Lau, D., Zygourakis, C., Scheer, J. K., Burch, S., Pekmezci, M., Chou, D., Tay, B., Mummaneni, P., Berven, S., Deviren, V., Ames, C. P. 2016; 41 (16): E964-72


    Retrospective cohort analysis.To evaluate the economic impact of revision surgery for proximal junctional failures (PJF) after thoracolumbar fusions for adult spinal deformity (ASD).PJF after fusions for ASD is a major cause of disability. Although clinical sequelae are described, PJF-revision operation costs are incompletely defined.Consecutive adults who underwent thoracolumbar fusions for ASD (August, 2003 to January, 2013) were evaluated. Inclusion criteria include construct from pelvis to L2 or above and minimum 6 months follow-up after the index ASD operation. Direct costs (surgical supplies/implants, room/care, pharmacy, services) were identified from medical billing data and calculated for index ASD operations and subsequent surgeries for PJF. Not included in direct cost data were indirect costs, charges, surgeon fees, or revision operations for indications other than PJF (i.e., pseudarthrosis). Patients were compared based on the construct's upper-instrumented vertebra: upper thoracic (UT: T1-6) versus thoracolumbar junction (TLjxn: T9-L2).Of 501 patients, 382 met inclusion criteria. Fifty-one patients [UT:14; TLjxn: 40 at index; average follow-up 32.6 months (6-92 months)] had revisions for PJF, which summed to $3.2 million total direct cost. Average direct cost of index operations for the cohort ($68,294) was significantly greater than PJF-revisions ($55,547). Compared with TLjxn, UT had a significantly higher average cost for index operations ($79,860 vs. $65,868). However, PJF-revision cases were similar in average cost (UT:$60,103; TLjxn:$53,920; P = 0.09). Costs of PJF amounted to an additional 12.1% of the total index surgical cost in 382 patients.Revision operations for PJF after long thoracolumbar fusions for ASD are associated with an average direct cost of $55,547 per case. Revision costs for PJF are similar based on the index procedure's upper-instrumented vertebra level. At a major tertiary center over a 10-year period, PJF came at a very significant economic expense amounting to $3.2 million for 57 cases.3.

    View details for DOI 10.1097/BRS.0000000000001523

    View details for PubMedID 26909838

  • Predictors of Variation in Neurosurgical Supply Costs and Outcomes Across 4904 Surgeries at a Single Institution. World neurosurgery Zygourakis, C. C., Valencia, V. n., Boscardin, C. n., Nayak, R. U., Moriates, C. n., Gonzales, R. n., Theodosopoulos, P. n., Lawton, M. T. 2016; 96: 177–83


    There is high variability in neurosurgical costs, and surgical supplies constitute a significant portion of cost. Anecdotally, surgeons use different supplies for various reasons, but there is little understanding of how supply choices affect outcomes. Our goal is to evaluate the effect of patient, procedural, and provider factors on supply cost and to determine if supply cost is associated with patient outcomes.We obtained patient information (age, gender, payor, case mix index [CMI], body mass index, admission source), procedural data (procedure type, length, date), provider information (name, case volume), and total surgical supply cost for all inpatient neurosurgical procedures from 2013 to 2014 at our institution (n = 4904). We created mixed-effect models to examine the effect of each factor on surgical supply cost, 30-day readmission, and 30-day mortality.There was significant variation in surgical supply cost between and within procedure types. Older age, female gender, higher CMI, routine/elective admission, longer procedure, and larger surgeon volume were associated with higher surgical supply costs (P < 0.05). Routine/elective admission and higher surgeon volume were associated with lower readmission rates (odds ratio, 0.707, 0.998; P < 0.01). Only patient factors of older age, male gender, private insurance, higher CMI, and emergency admission were associated with higher mortality (odds ratio, 1.029, 1.700, 1.692, 1.080, 2.809). There was no association between surgical supply cost and readmission or mortality (P = 0.307, 0.548).A combination of patient, procedural, and provider factors underlie the significant variation in neurosurgical supply costs at our institution. Surgical supply costs are not correlated with 30-day readmission or mortality.

    View details for PubMedID 27613498

  • Preventing Delays in First-Case Starts on the Neurosurgery Service: A Resident-Led Initiative at an Academic Institution. Journal of surgical education Han, S. J., Rolston, J. D., Zygourakis, C. C., Sun, M. Z., McDermott, M. W., Lau, C. Y., Aghi, M. K. 2016; 73 (2): 291–95


    On-time starts for the first case of the day are critical to maintaining efficiency in operating rooms (ORs). We studied whether a resident-led initiative to ensure on-time site marking and documentation of surgical consent could lead to improved first-case start time.In a resident-led initiative at a large 600-bed academic hospital with 25 ORs, we aimed to complete site marking and surgical consents half an hour before the scheduled start time for all first-case neurosurgical patients. We monitored the occurrence of delayed first starts and the length of delay during our initiative, and compared these cases to neurosurgical cases 3 months before the implementation of the initiative and to first-start nonneurosurgical cases.In the year of the initiative, both site marking and surgical consents were completed 30 minutes before the case start in 97% of neurosurgical cases. The average delay across all first-case starts was reduced to 7.17 minutes (N = 1271), compared with 9.67 minutes before the intervention (N = 345). During the study period, non-neurosurgical cases were delayed on average 10.3 minutes (N = 3592). There was a significant difference in latencies between the study period and the period before the initiative (p < 0.001), and also between neurosurgical cases and nonneurosurgical cases (p < 0.001). There was no reduction in delay times seen on the non-neurosurgical services in the study period when compared to the case 3 months before. Considering its effect across 1271 cases, this initiative over 1 year resulted in a total reduction of 52 hours and 57 minutes in delays.Through a resident-led quality improvement program, neurosurgical trainees successfully reduced delays in first-case starts on a surgical service. Engaging physician trainees in quality improvement and enhancing OR efficiency can be successfully achieved and can have a significant clinical and financial effect.

    View details for PubMedID 26774935

  • The impact of a patient education bundle on neurosurgery patient satisfaction. Surgical neurology international Kliot, T., Zygourakis, C. C., Imershein, S., Lau, C., Kliot, M. 2015; 6 (Suppl 22): S567-72


    As reimbursements and hospital/physician performance become ever more reliant on Hospital Consumer Assessment of Health Care Providers and Systems (HCAHPS) and other quality metrics, physicians are increasingly incentivized to improve patient satisfaction.A faculty and resident team at the University of California, San Francisco (UCSF) Department of Neurological Surgery developed and implemented a Patient Education Bundle. This consisted of two parts: The first was preoperative expectation letters (designed to inform patients of what to expect before, during, and after their hospitalization for a neurosurgical procedure); the second was a trifold brochure with names, photographs, and specialty/training information about the attending surgeons, resident physicians, and nurse practitioners on the neurosurgical service. We assessed patient satisfaction, as measured by HCAHPS scores and a brief survey tailored to our specific intervention, both before and after our Patient Education Bundle intervention.Prior to our intervention, 74.6% of patients responded that the MD always explained information in a way that was easy to understand. After our intervention, 78.7% of patients responded that the MD always explained information in a way that was easy to understand. "Neurosurgery Patient Satisfaction survey" results showed that 83% remembered receiving the preoperative letter; of those received the letter, 93% found the letter helpful; and 100% thought that the letter should be continued.Although effects were modest, we believe that patient education strategies, as modeled in our bundle, can improve patients' hospital experiences and have a positive impact on physician performance scores and hospital ratings.

    View details for DOI 10.4103/2152-7806.169538

    View details for PubMedID 26664909

    View details for PubMedCentralID PMC4653328

  • Cervical Fracture Stabilization within 72 Hours of Injury is Associated with Decreased Hospitalization Costs with Comparable Perioperative Outcomes in a Propensity Score-Matched Cohort. Cureus Medress, Z., Arrigo, R. T., Hayden Gephart, M., Zygourakis, C. C., Boakye, M. 2015; 7 (1)


    Prior studies have indicated that early decompression of traumatic cervical fractures can be performed safely and is associated with improved outcomes, though the economic impact of the timing of surgery in the American population has not been studied. After adjusting for patient, hospital, and injury confounders, we performed propensity score modeling (PSM) on a large clinical administrative database to determine associated costs depending upon timing of surgery for acute cervical fracture.A total of 3,348 patients with surgically treated, traumatic, cervical fractures were identified. Patients were sorted into early (within 72 hours of admission) and late (beyond 72 hours) surgery groups. PSM was able to match 2,132 early and late surgery patients on age, comorbidity, expected payer, trauma severity, hospital type, urgent admission, and surgical approach. Perioperative complications, mortality, and resource utilization were assessed.Late surgery was more frequently associated with increased age, more comorbidities, higher ICISS score, and non-private insurance. Following PSM matching, there were no significant, preoperative differences between early and late surgery groups. Surgery performed after 72 hours was associated with an increase in in-hospital complications (OR=1.3). The early surgery group was associated with decreased length of stay (11 days vs. 16 days, p <0.0001) and hospital charges ($237,786 v. $282,727, p <0.0001).After controlling for potential confounding differences through PSM matching and multivariate analyses, we found late surgery independently associated with increased in-hospital complications, length of stay, and hospital resource utilization. These data suggest surgery within 72 hours may decrease resource utilization without a corresponding increase in postoperative morbidity.

    View details for DOI 10.7759/cureus.244

    View details for PubMedID 26180668

    View details for PubMedCentralID PMC4494543

  • Pituicytomas and spindle cell oncocytomas: modern case series from the University of California, San Francisco. Pituitary Zygourakis, C. C., Rolston, J. D., Lee, H. S., Partow, C. n., Kunwar, S. n., Aghi, M. K. 2015; 18 (1): 150–58


    Pituicytomas and spindle cell oncocytomas (SCOs) are extremely rare neoplasms of the sellar and suprasellar region that can often mimic pituitary adenomas. To date, there are relatively few cases of pituicytomas and SCOs reported; and most of these are small case series.In this paper, we provide a retrospective review of the treatment, imaging characteristics, post-operative course, and histopathology of five cases of pituicytomas and two SCOs treated at the University of California, San Francisco (UCSF) over a 10-year period from 2003 to 2013.We find that pituicytomas and SCOs present similarly to pituitary adenomas, and look identical on CT or MR imaging. We histopathologically confirmed all pituicytomas with a combination of hematoxylin and eosin morphology and immunohistochemical positivity for vimentin and S100; SCOs stain for anti-mitochondrial antigen and endothelial membrane antigen. We observe positive thyroid transcription factor 1 (TTF1) immunohistochemistry in both cases of SCO, as well as in both of the cases of pituicytoma in which TTF1 staining was available.This represents the largest single-institution case series of pituicytomas and SCOs to date, and also includes the first description of the management of a pregnant female with SCO. Our findings are consistent with the idea of common histogenesis for pituicytomas and SCOs, and also raise the possibility of more aggressive growth in SCOs as compared to pituicytomas.

    View details for DOI 10.1007/s11102-014-0568-7

    View details for PubMedID 24823438

  • Management of central nervous system teratoma. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Zygourakis, C. C., Davis, J. L., Kaur, G. n., Ames, C. P., Gupta, N. n., Auguste, K. I., Parsa, A. T. 2015; 22 (1): 98–104


    Central nervous system (CNS) teratomas are very rare neoplasms that contain tissues derived from all three germ cell layers (endoderm, mesoderm, and ectoderm). Patients with teratomas usually have a good prognosis. Given the paucity of cases in the literature, we present a retrospective review of 15 CNS teratomas treated over a 25 year period at the University of California, San Francisco. We describe the presentation, location, treatment, and adjuvant therapy for these patients, and highlight three unique cases that emphasize the diverse presentation and treatment of these rare tumors.

    View details for PubMedID 25150764

  • Transient pupillary dilation following local papaverine application in intracranial aneurysm surgery. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Zygourakis, C. C., Vasudeva, V. n., Lai, P. M., Kim, A. H., Wang, H. n., Du, R. n. 2015; 22 (4): 676–79


    Isolated cases of transient pupillary changes after local intracisternal papaverine administration during aneurysm surgery have been reported. This study aimed to determine the prevalence and factors associated with this phenomenon. We assessed a total of 103 consecutive patients who underwent craniotomy for cerebral aneurysm clipping for the presence of postoperative pupillary dilation (mydriasis) after intracisternal papaverine administration. Univariate and multivariate logistic regression were conducted to evaluate the association of mydriasis with patient age, sex, duration of surgery, and aneurysm location. We observed either ipsilateral or bilateral pupillary dilation in the immediate postoperative period in nine out of 103 patients (8.7%). This phenomenon was not associated with patient age or sex. There was a trend towards positive correlation with aneurysms located at the anterior communicating artery (odds ratio 3.76, p=0.10), and a negative correlation with the duration of surgery (odds ratio 0.57, p=0.08). All pupillary dilation resolved within several hours, and the onset and resolution were consistent with the half-life of papaverine. To our knowledge, this represents the largest study of posteropative pupillary changes due to papaverine. The current findings are consistent with the small number of prior case reports of transient pupillary changes after papaverine administration and appear to reflect the local anesthetic action of papaverine on the oculomotor nerve.

    View details for PubMedID 25564265

  • Cost-effectiveness research in neurosurgery. Neurosurgery clinics of North America Zygourakis, C. C., Kahn, J. G. 2015; 26 (2): 189–96, viii


    Cost and value are increasingly important components of health care discussions. Despite a plethora of cost and cost-effectiveness analyses in many areas of medicine, there has been little of this type of research for neurosurgical procedures. This scarcity is vexing because this specialty represents one of the most expensive areas in medicine. This article discusses the general principles of cost-effectiveness analyses and reviews the cost- and cost-effectiveness-related research to date in neurosurgical subspecialties. The need for standardization of cost and cost-effectiveness measurement and reporting within neurosurgery is highlighted and a set of metrics for this purpose is defined.

    View details for PubMedID 25771274

  • Surgery is cost-effective treatment for young patients with vestibular schwannomas: decision tree modeling of surgery, radiation, and observation. Neurosurgical focus Zygourakis, C. C., Oh, T., Sun, M. Z., Barani, I., Kahn, J. G., Parsa, A. T. 2014; 37 (5): E8


    Vestibular schwannomas (VSs) are managed in 3 ways: observation ("wait and scan"); Gamma Knife surgery (GKS); or microsurgery. Whereas there is considerable literature regarding which management approach is superior, there are only a few studies addressing the cost of treating VSs, and there are no cost-utility analyses in the US to date.In this study, the authors used the University of California at San Francisco medical record and hospital accounting databases to determine total hospital charges and costs for 33 patients who underwent open surgery, 42 patients who had GKS, and 12 patients who were observed between 2010 and 2013. The authors then performed decision-tree analysis to determine which treatment paradigm produces the highest quality-adjusted life years and to calculate the incremental cost-effectiveness ratio, depending on the patient's age at VS diagnosis.The average total hospital cost over a 3-year period for surgically treated patients was $80,074 (± $49,678) versus $9737 (± $5522) for patients receiving radiosurgery and $1746 (± $2792) for patients who were observed. When modeling the most debilitating symptoms and worst outcomes of VSs (vertigo and death) at different ages at diagnosis, radiation is dominant to observation at all ages up to 70 years. Surgery is cost-effective when compared with radiation (incremental cost-effectiveness ratio < $150,000) at younger ages at diagnosis (< 45 years old).In this model, surgery is a cost-effective alternative to radiation when VS is diagnosed in patients at < 45 years. For patients ≥ 45 years, radiation is the most cost-effective treatment option.

    View details for DOI 10.3171/2014.8.FOCUS14435

    View details for PubMedID 26218621

  • Medical errors in neurosurgery. Surgical neurology international Rolston, J. D., Zygourakis, C. C., Han, S. J., Lau, C. Y., Berger, M. S., Parsa, A. T. 2014; 5 (Suppl 10): S435-40


    Medical errors cause nearly 100,000 deaths per year and cost billions of dollars annually. In order to rationally develop and institute programs to mitigate errors, the relative frequency and costs of different errors must be documented. This analysis will permit the judicious allocation of scarce healthcare resources to address the most costly errors as they are identified.Here, we provide a systematic review of the neurosurgical literature describing medical errors at the departmental level. Eligible articles were identified from the PubMed database, and restricted to reports of recognizable errors across neurosurgical practices. We limited this analysis to cross-sectional studies of errors in order to better match systems-level concerns, rather than reviewing the literature for individually selected errors like wrong-sided or wrong-level surgery.Only a small number of articles met these criteria, highlighting the paucity of data on this topic. From these studies, errors were documented in anywhere from 12% to 88.7% of cases. These errors had many sources, of which only 23.7-27.8% were technical, related to the execution of the surgery itself, highlighting the importance of systems-level approaches to protecting patients and reducing errors.Overall, the magnitude of medical errors in neurosurgery and the lack of focused research emphasize the need for prospective categorization of morbidity with judicious attribution. Ultimately, we must raise awareness of the impact of medical errors in neurosurgery, reduce the occurrence of medical errors, and mitigate their detrimental effects.

    View details for DOI 10.4103/2152-7806.142777

    View details for PubMedID 25371849

    View details for PubMedCentralID PMC4209704

  • What do hotels and hospitals have in common? How we can learn from the hotel industry to take better care of patients. Surgical neurology international Zygourakis, C. C., Rolston, J. D., Treadway, J., Chang, S., Kliot, M. 2014; 5 (Suppl 2): S49-53


    Despite widely divergent public perceptions and goals, hotels and hospitals share many core characteristics. Both serve demanding and increasingly well-informed clienteles, both employ a large hierarchy of workers with varying levels of responsibility, and both have payments that are increasingly tied to customer/patient evaluations. In the hotel industry, decades of management experience and market research have led to widespread improvements and innovations that improve customer satisfaction. But there has been incredibly little cross-fertilization between the hotel and hospital industries. In this paper, we first consider the changes in the healthcare system that are forcing hospitals to become more concerned with patient satisfaction. We discuss the similarities and differences between the hotel and hospital industries, and then outline several of the unique challenges that neurosurgeons face in taking care of patients and increasing their comfort. We cite specific lessons from the hotel industry that can be applied to patients' preadmission, check-in, hospital stay, discharge planning, and poststay experiences. We believe that hospitals can and should leverage the successful advances within the hotel industry to improve patient satisfaction, without having to repeat identical research or market experimentation. We hope this will lead to rapid improvements in patient experiences and overall wellbeing.

    View details for DOI 10.4103/2152-7806.128913

    View details for PubMedID 24818061

    View details for PubMedCentralID PMC4014833

  • Management of planum/olfactory meningiomas: predicting symptoms and postoperative complications. World neurosurgery Zygourakis, C. C., Sughrue, M. E., Benet, A. n., Parsa, A. T., Berger, M. S., McDermott, M. W. 2014; 82 (6): 1216–23


    Given their location and slow growth, olfactory groove and planum sphenoidale meningiomas often grow to large sizes before they present with clinical symptoms and pose significant surgical challenges. The goal of our study is to identify which preoperative symptoms and findings on magnetic resonance imaging are correlated with specific postoperative outcomes in order to better counsel patients preoperatively.We retrospectively identified 44 patients with planum/olfactory meningiomas treated at our institution from 1996 to 2006. We used univariate and multivariate regression models to analyze the effect of several magnetic resonance imaging characteristics (tumor volume, distance to optic chiasm, anterior cerebral artery encasement, paranasal sinus invasion, and sellar invasion) on preoperative symptoms and postoperative outcomes, including complication rate and tumor recurrence.Only brain tumor volume (>42 cm(3)), but not distance to the optic chiasm, is independently associated with an increased likelihood of preoperative visual symptoms. Tumors with nasal sinus invasion are significantly more likely to cause postoperative surgical complications, and tumors with anterior cerebral artery encasement are associated with a greater likelihood of both postoperative complications and tumor recurrence.We conclude that tumors larger than 3.4 cm in diameter and those whose posterior edge is within 6-8 mm of the optic chiasm should be recommended for early surgical intervention. In terms of predicting surgical complications, nasal sinus invasion and anterior cerebral artery encasement are associated with greater-risk profiles when surgery becomes necessary. Thus, it is prudent to take these specific variables into consideration when advising patients about the risks of observation and surgery for olfactory/planum meningiomas.

    View details for PubMedID 25108294

  • Morbidity of repeat transsphenoidal surgery assessed in more than 1000 operations. Journal of neurosurgery Jahangiri, A. n., Wagner, J. n., Han, S. W., Zygourakis, C. C., Han, S. J., Tran, M. T., Miller, L. M., Tom, M. W., Kunwar, S. n., Blevins, L. S., Aghi, M. K. 2014; 121 (1): 67–74


    OBJECT.: While transsphenoidal surgery is associated with low morbidity, the degree to which morbidity increases after reoperation remains unclear. The authors determined the morbidity associated with repeat versus initial transsphenoidal surgery after 1015 consecutive operations.The authors conducted a 5-year retrospective review of the first 916 patients undergoing transsphenoidal surgery at their institution after a pituitary center of expertise was established, and they analyzed morbidities.The authors analyzed 907 initial and 108 repeat transsphenoidal surgeries performed in 916 patients (9 initial surgeries performed outside the authors' center were excluded). The most common diagnoses were endocrine inactive (30%) or active (36%) adenomas, Rathke's cleft cysts (10%), and craniopharyngioma (3%). Morbidity of initial surgery versus reoperation included diabetes insipidus ([DI] 16% vs 26%; p = 0.03), postoperative hyponatremia (20% vs 16%; p = 0.3), new postoperative hypopituitarism (5% vs 8%; p = 0.3), CSF leak requiring repair (1% vs 4%; p = 0.04), meningitis (0.4% vs 3%; p = 0.02), and length of stay ([LOS] 2.8 vs 4.5 days; p = 0.006). Of intraoperative parameters and postoperative morbidities, 1) some (use of lumbar drain and new postoperative hypopituitarism) did not increase with second or subsequent reoperations (p = 0.3-0.9); 2) some (DI and meningitis) increased upon second surgery (p = 0.02-0.04) but did not continue to increase for subsequent reoperations (p = 0.3-0.9); 3) some (LOS) increased upon second surgery and increased again for subsequent reoperations (p < 0.001); and 4) some (postoperative hyponatremia and CSF leak requiring repair) did not increase upon second surgery (p = 0.3) but went on to increase upon subsequent reoperations (p = 0.001-0.02). Multivariate analysis revealed that operation number, but not sex, age, pathology, radiation therapy, or lesion size, increased the risk of CSF leak, meningitis, and increased LOS. Separate analysis of initial versus repeat transsphenoidal surgery on the 2 most common benign pituitary lesions, pituitary adenomas and Rathke's cleft cysts, revealed that the increased incidence of DI and CSF leak requiring repair seen when all pathologies were combined remained significant when analyzing only pituitary adenomas and Rathke's cleft cysts (DI, 13% vs 35% [p = 0.001]; and CSF leak, 0.3% vs 9% [p = 0.0009]).Repeat transsphenoidal surgery was associated with somewhat more frequent postoperative DI, meningitis, CSF leak requiring repair, and greater LOS than the low morbidity characterizing initial transsphenoidal surgery. These results provide a framework for neurosurgeons in discussing reoperation for pituitary disease with their patients.

    View details for DOI 10.3171/2014.3.JNS131532

    View details for PubMedID 24834943

  • Modern treatment of 84 newly diagnosed craniopharyngiomas. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia Zygourakis, C. C., Kaur, G. n., Kunwar, S. n., McDermott, M. W., Madden, M. n., Oh, T. n., Parsa, A. T. 2014; 21 (9): 1558–66


    There is debate regarding the appropriate treatment for craniopharyngiomas, which often present symptomatically given their proximity to critical brain structures, and pose significant surgical challenges. The goal of this study is to identify which patient and tumor characteristics are associated with specific preoperative symptoms, surgical complications, patient outcomes, and tumor recurrence in order to guide craniopharyngioma treatment. We retrospectively identified 84 patients with newly diagnosed craniopharyngiomas treated at our institution from 1986-2010. We used binary logistic regression and survival analysis to determine the effect of several variables (including sex, age, tumor size, location, surgical approach, and extent of resection) on preoperative symptoms and postoperative outcomes, including complication rates and tumor recurrence. Age and tumor location were associated with increased rates of preoperative symptoms, with children being more likely than adults to present with endocrine dysfunction, and intraventricular tumors being more likely than extraventricular tumors to present with headaches and hydrocephalus. A transcranial surgical approach was associated with 1.5 times higher rate of surgical complications than transsphenoidal surgery, while only intraventricular tumor location was associated with a poorer patient outcome. The main factor significantly associated with tumor recurrence was extent of resection. We conclude that intraventricular tumor location is most highly correlated with preoperative symptoms. If feasible, transsphenoidal approaches are preferred, as they result in fewer surgical complications, and gross total resections are optimal because they lead to lower rates of recurrence. When gross total resection is not possible, we favor multimodal treatment approaches.

    View details for PubMedID 24908374

  • Trends in the diagnosis and treatment of pediatric primary spinal cord tumors. Journal of neurosurgery. Pediatrics Hayden Gephart, M. G., Lober, R. M., Arrigo, R. T., Zygourakis, C. C., Guzman, R., Boakye, M., Edwards, M. S., Fisher, P. G. 2012; 10 (6): 555-559


    Pediatric primary spinal cord tumors (PSCTs) are rare, with limited comprehensive data regarding incidence and patterns of diagnosis and treatment. The authors evaluated trends in the diagnosis and treatment of PSCTs using a nationwide database.The Surveillance, Epidemiology, and End Results (SEER) registry was queried for the years 1975-2007, evaluating clinical patterns in 330 patients 19 years of age or younger in whom a pediatric PSCT had been diagnosed. Histological diagnoses were grouped into pilocytic astrocytoma, other low-grade astrocytoma, ependymoma, and high-grade glioma. Patient demographics, tumor pathology, use of external beam radiation (EBR), and overall survival were analyzed.The incidence of pediatric PSCT was 0.09 case per 100,000 person-years and did not change over time. Males were more commonly affected than females (58% vs 42%, respectively; p < 0.006). Over the last 3 decades, the specific diagnoses of pilocytic astrocytoma and ependymoma increased, whereas the use of EBR decreased (60.6% from 1975 to 1989 vs 31.3% from 1990 to 2007; p < 0.0001). The 5- and 10-year survival rates did not differ between these time periods.While the incidence of pediatric PSCT has not changed over time, the pattern of pathological diagnoses has shifted, and pilocytic astrocytoma and ependymoma have been increasingly diagnosed. The use of EBR over time has declined. Relative survival of patients with low-grade PSCT has remained high regardless of the pathological diagnosis.

    View details for DOI 10.3171/2012.9.PEDS1272

    View details for PubMedID 23061821

  • Trends in the diagnosis and treatment of pediatric primary spinal cord tumors Clinical article JOURNAL OF NEUROSURGERY-PEDIATRICS Gephart, M. G., Lober, R. M., Arrigo, R. T., Zygourakis, C. C., Guzman, R., Boakye, M., Edwards, M. S., Fisher, P. G. 2012; 10 (6): 555-559
  • Venous Thromboembolism After Thoracic/Thoracolumbar Spinal Fusion WORLD NEUROSURGERY Gephart, M. G., Zygourakis, C. C., Arrigo, R. T., Kalanithi, P. S., Lad, S. P., Boakye, M. 2012; 78 (5): 545-552


    Venous thromboembolism (VTE), which includes deep venous thrombosis and pulmonary embolism, is a serious and potentially fatal surgical complication. The goal of our study was to examine preoperative characteristics, incidence, and outcomes of patients with VTE after elective thoracic/thoracolumbar level spine fusion.We identified 430,081 patients from the Nationwide Inpatient Sample database who underwent spinal fusion between 2002 and 2008. Patients undergoing thoracic/thoracolumbar level fusion (n = 8617) were found to have the greatest concurrent rate of VTE. We then performed multivariate analyses on this cohort to identify predictors of and outcomes after VTE in patients undergoing thoracic/thoracolumbar level fusion.The overall VTE rate in spinal fusion surgery was 0.40% (cervical = 0.22%, thoracic/thoracolumbar = 1.90%, lumbar/lumbosacral = 0.49%, re-fusions = 0.64%, and fusions not otherwise specified = 0.84%). On multivariate logistic regression analysis of patients undergoing spinal fusion at the thoracic/thoracolumbar level, increasing age, Medicare insurance coverage (vs. private insurance), urban teaching hospital (vs. urban nonteaching hospital), combined anterior/posterior surgical approach (vs. posterior-only approach), and the presence of congestive heart failure or weight loss (Elixhauser comorbidity groups) were each independently associated with an increased odds ratio of VTE complication. VTE after thoracic/thoracolumbar surgery was significantly associated with longer hospital stays (16.6 vs. 6.74 days), increased total hospital costs ($260,208 vs. $115,474), and increased mortality (4.33% vs. 0.33%).Multivariate logistic regression analysis reveals age, insurance status, hospital type, combined anterior/posterior surgical approach, and the presence of congestive heart failure or weight loss to be independently associated with an increased odds ratio of VTE complication. This complication is associated with increased hospital costs, length of stay, and overall mortality.

    View details for DOI 10.1016/j.wneu.2011.12.089

    View details for Web of Science ID 000311996100038

    View details for PubMedID 22381270

  • Retrospective, Propensity Score-Matched Cohort Study Examining Timing of Fracture Fixation for Traumatic Thoracolumbar Fractures JOURNAL OF NEUROTRAUMA Boakye, M., Arrigo, R. T., Gephart, M. G., Zygourakis, C. C., Lad, S. 2012; 29 (12): 2220-2225


    The timing of surgery in patients with traumatic thoracic/thoracolumbar fractures, with or without spinal cord injury, remains controversial. The objective of this study was to determine the importance of the timing of surgery for complications and resource utilization following fixation of traumatic thoracic/thoracolumbar fractures. In this retrospective cohort study, the 2003-2008 California Inpatient Databases were searched for patients receiving traumatic thoracic/thoracolumbar fracture fixation. Patients were classified as having early (<72 h) or late (>72 h) surgery. Propensity score modeling produced a matched cohort balanced on age, comorbidity, trauma severity, and other factors. Complications, mortality, length of stay, and hospital charges were assessed. Multivariate logistic regression was used to determine the impact of delayed surgery on in-hospital complications after balancing and controlling for other important factors. Early surgery (<72 h) for traumatic thoracic/thoracolumbar fractures was associated with a significantly lower overall complication rate (including cardiac, thromboembolic, and respiratory complications), and decreased hospital stay. In-hospital charges were significantly lower ($38,120 difference) in the early surgery group. Multivariate analysis identified time to surgery as the strongest predictor of in-hospital complications, although age, medical comorbidities, and injury severity score were also independently associated with increased complications. We reinforce the beneficial impact of early spinal surgery (prior to 72 h) in traumatic thoracic/thoracolumbar fractures to reduce in-hospital complications, hospital stay, and resource utilization. These results provide further support to the emerging literature and professional consensus regarding the importance of early thoracic/thoracolumbar spine stabilization of traumatic fractures to improve patient outcomes and limit hospitalization costs.

    View details for DOI 10.1089/neu.2012.2364

    View details for Web of Science ID 000307859900009

    View details for PubMedID 22676801

  • Immunotherapy for glioma: promises and challenges. Neurosurgery clinics of North America Han, S. J., Zygourakis, C. n., Lim, M. n., Parsa, A. T. 2012; 23 (3): 357–70


    Novel immunotherapeutic modalities are being pursed in the treatment of high-grade gliomas. This article explains how tumors suppress immune function in the brain. It specifically describes the ways in which tumors limit effective communication with immune cells, secrete immune-inhibitory cytokines and molecules, and express molecules that induce apoptosis of immune cells. It also defines 3 different immunotherapeutic approaches to counteract this tumor-associated immunosuppression: cytokine therapy, passive immunotherapy (either serotherapy or adoptive immunotherapy), and active immunotherapy. Although immunotherapeutic approaches have met with mixed success so far, immunotherapy continues to be actively pursued because of its potential to attack infiltrating high-grade gliomas.

    View details for DOI 10.1016/

    View details for PubMedID 22748649

  • Delayed development of os odontoideum after traumatic cervical injury: support for a vascular etiology. Journal of neurosurgery. Pediatrics Zygourakis, C. C., Cahill, K. S., Proctor, M. R. 2011; 7 (2): 201–4


    A previously healthy 2-year-old girl sustained a C1-2 ligamentous injury after a motor vehicle accident and underwent successful halo immobilization, with postimmobilization images showing good cervical alignment. At the time, plain radiography, CT scanning, and MR imaging showed a normal odontoid. Four years later, however, the patient was found to have an os odontoideum, evident on plain radiography and CT imaging. At the 10-year follow-up, the os odontoideum had not been surgically repaired, and the child had mild hypermobility. This is the first documented case in the modern imaging era of delayed os odontoideum formation after definitive CT scanning showed no fracture. As such, this suggests that os odontoideum may result from traumatic vascular interruption in the developing spine, with resulting osseous remodeling leading to an os odontoideum. This case argues against the congenital etiology of os odontoideum, as well as the strict posttraumatic theory whereby a trauma-induced odontoid fracture leads to osseous remodeling and subsequent development of an os odontoideum.

    View details for PubMedID 21284467

  • Nitric oxide-generating hydrogels inhibit neointima formation. Journal of biomaterials science. Polymer edition Masters, K. S., Lipke, E. A., Rice, E. E., Liel, M. S., Myler, H. A., Zygourakis, C., Tulis, D. A., West, J. L. 2005; 16 (5): 659-72


    This study evaluated the effects of localized delivery of nitric oxide (NO) from hydrogels covalently modified with S-nitrosocysteine (Cys-NO) on neoinitma formation, a key component of restenosis, in a rat balloon-injury model. Soluble Cys-NO was used in preliminary studies to identify dosage ranges that were able to simultaneously inhibit smooth muscle cell proliferation, enhance endothelial cell proliferation, and reduce platelet adhesion. Photo-cross-linked PEG-based hydrogels were formed with covalently immobilized Cys-NO. These materials release NO for approximately 24 h and can be applied to tissues and photo-cross-linked in situ to form local drug-delivery systems. Localized delivery of NO from hydrogels containing Cys-NO inhibited neointima formation in a rat balloon-injury model by approximately 75% at 14 days.

    View details for PubMedID 16001723

  • Quantitative trait loci modulate ventricular size in the mouse brain JOURNAL OF COMPARATIVE NEUROLOGY Zygourakis, C. C., Rosen, G. D. 2003; 461 (3): 362-369


    Cerebral ventricular size in humans varies significantly. Abnormal enlargement of the ventricles has been associated with schizophrenia, and hydrocephalus can lead to serious cognitive and motor deficiencies in humans and animals. In this study, we mapped quantitative trait loci (QTLs) modulating cerebroventricular size in mice. We hypothesized that genes underlying hydrocephalus might also modulate normal variation in ventricular size. By using digital images of mouse brain sections and stereological techniques, we estimated the volume of the combined lateral and third ventricles, as well as the volume of the entire brain, in 228 AXB and BXA recombinant inbred mice and their parent strains (A/J and C57BL/6J). Ventricle size, expressed as percentage of brain volume, is a heritable trait (h(2) = 0.32). We detected a major QTL controlling variance in volume on chromosome (Chr) 8 near the markers D8Mit94 and D8Mit189. We also detected a strong epistatic interaction affecting ventricular volume between loci on Chr 4 (near D4Mit237 and D4Mit214) and on Chr 7 (D7Mit178 and D7Mit191). These three QTLs, labeled Vent8a, Vent4b, and Vent7c, are close to genes that have been previously implicated in hydrocephalus.

    View details for DOI 10.1002/cne.10697

    View details for Web of Science ID 000183172500007

    View details for PubMedID 12746874