Atman Desai, MD

All Publications

• Determining critical monitoring periods for accurate wearable step counts in patients with degenerative spine disorders. Scientific reports Gonzalez-Suarez, A. D., Maldaner, N., Tang, M., Fatemi, P., Leung, C., Desai, A., Tomkins-Lane, C., Han, S. S., Zygourakis, C. 2024; 14 (1): 19988

  Abstract

  Longitudinal physical activity monitoring is a novel and promising objective outcome measure for patients with degenerative spine disorder (DSD) that currently lacks established standards for data collection and interpretation. Here, we monitored 100 patients with DSD with the Apple Watch to establish the optimal duration and pattern of step count monitoring needed to estimate their weekly physical activity before their elective surgery. Participants were predominantly female (65.3%), had an average age of 61.5 years, and showed consistent step counts between preoperative days, as well as across weekends and weekdays. Intraclass correlations (ICC) analysis showed that a step count average over 2 days achieved an ICC of 0.92 when compared to a 7-day average before surgery, while 4 days were required for a similar agreement of 0.93 with a 14-day average. Sequential linear regression demonstrated that incorporating additional preoperative days improved the model's ability to predict 7- and 14-days step count averages. We conclude that, while daily preoperative step counts remain relatively stable, longer activity monitoring is necessary to account for the variance in step count over an increasing time frame, and the full extent of data fluctuation may only become apparent with long-term trend analysis.

  View details for DOI 10.1038/s41598-024-70912-7

  View details for PubMedID 39198534

  View details for PubMedCentralID 4766830

• Changes in Alignment at Untreated Vertebral Levels Following Short-Segment Fusion Using Personalized Interbody Cages: Leveraging Personalized Medicine to Reduce the Risk of Reoperation. International journal of spine surgery Mullin, J. P., Asghar, J., Patel, A. I., Osorio, J. A., Smith, J. S., Ames, C. P., Small, J., Desai, A., Ponticorvo, A., Nicolau, R. J. 2024

  Abstract

  An abnormal postoperative lordosis distribution index (LDI), which quantifies the ratio between the lordosis at L4 to S1 and the lordosis at L1 to S1, contributes to the development of adjacent segment disease and increased revision rates in patients undergoing short-segment lumbar intervertebral fusions. Incorporating preoperative spinopelvic parameters and LDI into the surgical plan for short-segment fusion is important for guiding alignment restoration and preserving normal preoperative alignment in unfused segments. This study examined changes in LDI, segmental lordosis, and lordosis of the unfused levels in patients treated with personalized interbody cage (PIC) implants.This retrospective study evaluated radiographic measurements from 111 consecutively treated patients diagnosed with degenerative spinal conditions and treated with a short-segment fusion of L4 to L5, L5 to S1, or L4 to S1 using PIC implant(s) within 6 months of the fusion procedure. Comparisons of intervertebral lordosis for treated and untreated levels as well as LDI pre- and postoperatively were performed.In patients with a preoperative hypolordotic distribution (LDI < 50%), statistically significant increases were found in LDI postoperatively, approaching the normal LDI range (LDI 50%-80%). Likewise, patients with hyperlordotic distribution preoperatively (LDI > 80%) experienced a decrease in LDI postoperatively, trending toward the normal range, although the changes were not statistically significant. Intervertebral lordosis for the L5 to S1 level increased significantly following the placement of a PIC in the normal and hypolordotic LDI groups. Changes in intervertebral lordosis for L5 to S1 were not significant for patients with preoperative hyperlordotic LDI. Reciprocal changes in intervertebral lordosis at L1 to L4 were not observed in any groups.PIC implants may provide a benefit for patients, particularly those with hypolordotic distributions preoperatively. They have the potential to further improve patient outcomes by helping surgeons to achieve patient-specific lordosis goals, which may help to reduce the risk of adjacent segment disease and revisions in patients undergoing short-segment lumbar intervertebral fusions.Personalized implants can help surgeons achieve patient-specific alignment goals, potentially prevent adjacent segment disease, and reduce long-term reinterventions.

  View details for DOI 10.14444/8639

  View details for PubMedID 39187298

• Mismatch Between Pelvic Incidence and Lumbar Lordosis After Personalized Interbody Fusion: The Importance of Preoperative Planning and Alignment in Degenerative Spine Diseases. International journal of spine surgery Asghar, J., Patel, A. I., Osorio, J. A., Smith, J. S., Small, J., Mullin, J. P., Desai, A., Temple-Wong, M., Nicolau, R. J. 2024

  Abstract

  Emerging data have highlighted the significance of planning and aligning total and segmental lumbar lordosis with pelvic morphology when performing short-segment fusion with the goal of reducing the risk of adjacent segment disease while also decreasing spine-related disability. This study evaluates the impact of personalized interbody implants in restoring pelvic incidence-lumbar lordosis (PI-LL) mismatch compared with a similar study using stock interbody implants.This multicenter retrospective analysis assessed radiographic pre- and postoperative spinopelvic alignment (PI-LL) in patients who underwent 1- or 2-level lumbar fusions with personalized interbody implants for degenerative (nondeformity) indications. The aim was to assess the incidence of malalignment (PI-LL ≥ 10°) both before and after fusion surgery and to determine the rate of alignment preservation and/or correction in this population.There were 135 patients included in this study. Of 83 patients who were aligned preoperatively, alignment was preserved in 76 (91.6%) and worsened in 7 (8.4%). Among the 52 preoperatively malaligned patients, alignment was restored in 23 (44.2%), and 29 (55.8%) were not fully corrected. Among patients who were preoperatively aligned, there was no statistically significant difference in either the "preserved" or "worsened" groups between stock devices and personalized interbody devices. In contrast, among patients who were preoperatively malaligned, there was a statistically significant increase in the "restored" group (P = 0.046) and a statistically significant decrease in the "worsened" groups in patients with personalized interbodies compared with historical stock device data (P < 0.05).Compared with a historical cohort with stock implants, personalized interbody implants in short-segment fusions have shown a statistically significant improvement in restoring patients to normative PI-LL. Using 3-dimensional preoperative planning combined with personalized implants provides an important tool for planning and achieving improvement in spinopelvic parameters.

  View details for DOI 10.14444/8638

  View details for PubMedID 39187299

• Using Machine Learning Models to Identify Factors Associated With 30-Day Readmissions After Posterior Cervical Fusions: A Longitudinal Cohort Study. Neurospine Gonzalez-Suarez, A. D., Rezaii, P. G., Herrick, D., Tigchelaar, S. S., Ratliff, J. K., Rusu, M., Scheinker, D., Jeon, I., Desai, A. M. 2024

  Abstract

  Readmission rates after posterior cervical fusion (PCF) significantly impact patients and healthcare, with complication rates at 15%-5% and up to 12% 90-day readmission rates. In this study, we aim to test whether machine learning (ML) models that capture interfactorial interactions outperform traditional logistic regression (LR) in identifying readmission-associated factors.The Optum Clinformatics Data Mart database was used to identify patients who underwent PCF between 2004-2017. To determine factors associated with 30-day readmissions, 5 ML models were generated and evaluated, including a multivariate LR (MLR) model. Then, the best-performing model, Gradient Boosting Machine (GBM), was compared to the LACE (Length patient stay in the hospital, Acuity of admission of patient in the hospital, Comorbidity, and Emergency visit) index regarding potential cost savings from algorithm implementation.This study included 4,130 patients, 874 of which were readmitted within 30 days. When analyzed and scaled, we found that patient discharge status, comorbidities, and number of procedure codes were factors that influenced MLR, while patient discharge status, billed admission charge, and length of stay influenced the GBM model. The GBM model significantly outperformed MLR in predicting unplanned readmissions (mean area under the receiver operating characteristic curve, 0.846 vs. 0.829; p<0.001), while also projecting an average cost savings of 50% more than the LACE index.Five models (GBM, XGBoost [extreme gradient boosting], RF [random forest], LASSO [least absolute shrinkage and selection operator], and MLR) were evaluated, among which, the GBM model exhibited superior predictive performance, robustness, and accuracy. Factors associated with readmissions impact LR and GBM models differently, suggesting that these models can be used complementarily. When analyzing PCF procedures, the GBM model resulted in greater predictive performance and was associated with higher theoretical cost savings for readmissions associated with PCF complications.

  View details for DOI 10.14245/ns.2347340.670

  View details for PubMedID 38768945

• 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

  Abstract

  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

• 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

  Abstract

  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

• Automated Labeling of Spondylolisthesis Cases through Spinal MRI Radiology Report Interpretation using ChatGPT Moallem, G., Gonzalez, A., Desai, A., Rusu, M., Chen, W., Astley, S. M. SPIE-INT SOC OPTICAL ENGINEERING. 2024

  View details for DOI 10.1117/12.3006999

  View details for Web of Science ID 001208134600098

• 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

  Abstract

  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

• Treatment of intramedullary spinal cord tumors: a modified Delphi technique of the North American Spine Society Section of Spine Oncology. Journal of neurosurgery. Spine Hersh, A. M., Pennington, Z., Lubelski, D., Elsamadicy, A. A., Dea, N., Desai, A., Gokaslan, Z. L., Goodwin, C. R., Hsu, W., Jallo, G. I., Krishnaney, A., Laufer, I., Lo, S. L., Macki, M., Mehta, A. I., Ozturk, A., Shin, J. H., Soliman, H., Sciubba, D. M. 2023: 1-10

  Abstract

  OBJECTIVE: Intramedullary spinal cord tumors (IMSCTs) are rare tumors with heterogeneous presentations and natural histories that complicate their management. Standardized guidelines are lacking on when to surgically intervene and the appropriate aggressiveness of resection, especially given the risk of new neurological deficits following resection of infiltrative tumors. Here, the authors present the results of a modified Delphi method using input from surgeons experienced with IMSCT removal to construct a framework for the operative management of IMSCTs based on the clinical, radiographic, and tumor-specific characteristics.METHODS: A modified Delphi technique was conducted using a group of 14 neurosurgeons experienced in IMSCT resection. Three rounds of written correspondence, surveys, and videoconferencing were carried out. Participants were queried about clinical and radiographic criteria used to determine operative candidacy and guide decision-making. Members then completed a final survey indicating their choice of observation or surgery, choice of resection strategy, and decision to perform duraplasty, in response to a set of patient- and tumor-specific characteristics. Consensus was defined as ≥ 80% agreement, while responses with 70%-79% agreement were defined as agreement.RESULTS: Thirty-six total characteristics were assessed. There was consensus favoring surgical intervention for patients with new-onset myelopathy (86% agreement), chronic myelopathy (86%), or progression from mild to disabling numbness (86%), but disagreement for patients with mild numbness or chronic paraplegia. Age was not a determinant of operative candidacy except among frail patients, who were deemed more suitable for observation (93%). Well-circumscribed (93%) or posteriorly located tumors reaching the surface (86%) were consensus surgical lesions, and participants agreed that the presence of syringomyelia (71%) and peritumoral T2 signal change (79%) were favorable indications for surgery. There was consensus that complete loss of transcranial motor evoked potentials with a 50% decrease in the D-wave amplitude should halt further resection (93%). Preoperative symptoms seldom influenced choice of resection strategy, while a distinct cleavage plane (100%) or visible tumor-cord margins (100%) strongly favored gross-total resection.CONCLUSIONS: The authors present a modified Delphi technique highlighting areas of consensus and agreement regarding surgical management of IMSCTs. Although not intended as a substitute for individual clinical decision-making, the results can help guide care of these patients. Additionally, areas of controversy meriting further investigation are highlighted.

  View details for DOI 10.3171/2023.8.SPINE23190

  View details for PubMedID 37856379

• Identification of Factors Associated With 30-Day Readmissions After Posterior Lumbar Fusion Using Machine Learning and Traditional Models: A National Longitudinal Database Study. Spine Rezaii, P. G., Herrick, D., Ratliff, J. K., Rusu, M., Scheinker, D., Desai, A. M. 2023

  Abstract

  STUDY DESIGN: Retrospective cohort study.OBJECTIVE: To identify factors associated with readmissions after PLF using machine learning and logistic regression (LR) models.SUMMARY OF BACKGROUND DATA: Readmissions following posterior lumbar fusion (PLF) place significant health and financial burden on the patient and overall healthcare system.METHODS: The Optum Clinformatics Data Mart database was used to identify patients who underwent posterior lumbar laminectomy, fusion, and instrumentation between 2004 and 2017. Four machine learning models and a multivariable LR model were used to assess factors most closely associated with 30-day readmission. These models were also evaluated in terms of ability to predict unplanned 30-day readmissions. The top performing model (Gradient Boosting Machine; GBM) was then compared to the validated LACE index in terms of potential cost savings associated with implementation of the model.RESULTS: A total of 18,981 patients were included, of which 3,080 (16.2%) were readmitted within 30 days of initial admission. Discharge status, prior admission, and geographic division were most influential for the LR model, while discharge status, length of stay, and prior admissions had greatest relevance for the GBM model. GBM outperformed LR in predicting unplanned 30-day readmission (mean AUC 0.865 vs. 0.850, P<0.0001). Use of GBM also achieved a projected 80% decrease in readmission-associated costs relative to those achieved by the LACE index model.CONCLUSIONS: Factors associated with readmission vary in terms of predictive influence based on standard logistic regression and machine learning models used, highlighting the complementary roles these models have in identifying relevant factors for prediction of 30-day readmissions. For posterior lumbar fusion procedures, Gradient Boosting Machine yielded greatest predictive ability and associated cost savings for readmission.LEVEL OF EVIDENCE: 3.

  View details for DOI 10.1097/BRS.0000000000004664

  View details for PubMedID 37027190

• Extreme Far-Lateral Approach for Recurrent Chordoma: 3-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Vigo, V., Asmaro, K. P., Nunez, M. A., Bobrow, A., Dodd, R. L., Desai, A., Fernandez-Miranda, J. C. 2023

  View details for DOI 10.1227/ons.0000000000000584

  View details for PubMedID 36719953

• Augmented Reality-Assisted Resection of a Large Presacral Ganglioneuroma: 2-Dimensional Operative Video. Operative neurosurgery (Hagerstown, Md.) Medress, Z. A., Bobrow, A., Tigchelaar, S. S., Henderson, T., Parker, J. J., Desai, A. 2022

  View details for DOI 10.1227/ons.0000000000000542

  View details for PubMedID 36701554

• 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

  Abstract

  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

• Augmented reality neuronavigation for en bloc resection of spinal column lesions. World neurosurgery Tigchelaar, S. S., Medress, Z. A., Quon, J., Dang, P., Barbery, D., Bobrow, A., Kin, C., Louis, R., Desai, A. 2022

  Abstract

  Primary tumors involving the spine are relatively rare but represent surgically challenging procedures with high patient morbidity. En bloc resection of these tumors necessitates large exposures, wide tumor margins, and poses risks to functionally relevant anatomical structures. Augmented reality Neuronavigation (ARNV) represents a paradigm shift in neuronavigation, allowing on-demand visualization of 3-Dimensional navigation data in real-time directly in line with the operative field. Here, we describe the first application of ARNV to perform distal sacrococcygectomies for the en bloc removal of sacral and retrorectal lesions involving the coccyx in two patients, as well as a thoracic 9-11 laminectomy with costotransversectomy for en bloc removal of a schwannoma in a third patient. In our experience, ARNV allowed our teams to minimize the length of the incision, reduce the extent of bony resection, and enhanced visualization of critical adjacent anatomy. All tumors were resected en bloc, and the patients recovered well postoperatively, with no known complications. Pathologic analysis confirmed the en bloc removal of these lesions with negative margins. We conclude that AR is an effective strategy for the precise, en bloc removal of spinal lesions including both sacrococcygeal tumors involving the retrorectal space and thoracic schwannomas.

  View details for DOI 10.1016/j.wneu.2022.08.143

  View details for PubMedID 36096393

• 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

  Abstract

  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

• Prediction of Discharge Status and Readmissions after Resection of Intradural Spinal Tumors. Neurospine Jin, M. C., Ho, A. L., Feng, A. Y., Medress, Z. A., Pendharkar, A. V., Rezaii, P., Ratliff, J. K., Desai, A. M. 2022; 19 (1): 133-145

  Abstract

  OBJECTIVE: Intradural spinal tumors are uncommon and while associations between clinical characteristics and surgical outcomes have been explored, there remains a paucity of literature unifying diverse predictors into an integrated risk model. To predict postresection outcomes for patients with spinal tumors.METHODS: IBM MarketScan Claims Database was queried for adult patients receiving surgery for intradural tumors between 2007 and 2016. Primary outcomes-of-interest were nonhome discharge and 90-day postdischarge readmissions. Secondary outcomes included hospitalization duration and postoperative complications. Risk modeling was developed using a regularized logistic regression framework (LASSO, least absolute shrinkage and selection operator) and validated in a withheld subset.RESULTS: A total of 5,060 adult patients were included. Most surgeries utilized a posterior approach (n = 5,023, 99.3%) and tumors were most commonly found in the thoracic region (n = 1,941, 38.4%), followed by the lumbar (n = 1,781, 35.2%) and cervical (n = 1,294, 25.6%) regions. Compared to models using only tumor-specific or patient-specific features, our integrated models demonstrated better discrimination (area under the curve [AUC] [nonhome discharge] = 0.786; AUC [90-day readmissions] = 0.693) and accuracy (Brier score [nonhome discharge] = 0.155; Brier score [90-day readmissions] = 0.093). Compared to those predicted to be lowest risk, patients predicted to be highest-risk for nonhome discharge required continued care 16.3 times more frequently (64.5% vs. 3.9%). Similarly, patients predicted to be at highest risk for postdischarge readmissions were readmitted 7.3 times as often as those predicted to be at lowest risk (32.6% vs. 4.4%).CONCLUSION: Using a diverse set of clinical characteristics spanning tumor-, patient-, and hospitalization-derived data, we developed and validated risk models integrating diverse clinical data for predicting nonhome discharge and postdischarge readmissions.

  View details for DOI 10.14245/ns.2143244.622

  View details for PubMedID 35378587

• Surgical Outcomes of Human Immunodeficiency Virus-positive Patients Undergoing Lumbar Degenerative Surgery. Clinical spine surgery Varshneya, K., Wadhwa, H., Ho, A. L., Medress, Z. A., Stienen, M. N., Desai, A., Ratliff, J. K., Veeravagu, A. 2021

  Abstract

  STUDY DESIGN: This was a retrospective cohort studying using a national administrative database.OBJECTIVE: The objective of this study was to determine the postoperative complications and quality outcomes of the human immunodeficiency virus (HIV)-positive patients undergoing surgical management for lumbar degenerative disease (LDD).METHODS: This study identified patients with who underwent surgery for LDD between 2007 and 2016. Patients were stratified based on whether they were HIV positive at the time of surgery. Multivariate regression was utilized to reduce the confounding of baseline covariates. Patients who underwent 3 or more levels of surgical correction were under the age of 18 years, or those with any prior history of trauma or tumor were excluded from this study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.RESULTS: A total of 120,167 patients underwent primary lumbar degenerative surgery, of which 309 (0.26%) were HIV positive. In multivariate regression analysis, the HIV-positive cohort was more likely to be readmitted at 30 days [odds ratio (OR)=1.9, 95% confidence interval (CI): 1.2-2.8], 60 days (OR=1.7, 95% CI: 1.2-2.5), and 90 days (OR=1.5, 95% CI: 1.0-2.2). The HIV-positive cohort was also more likely to experience any postoperative complication (OR=1.7, 95% CI: 1.2-2.3). Of the major drivers identified, HIV-positive patients had significantly greater odds of cerebrovascular disease and postoperative neurological complications (OR=3.8, 95% CI: 1.8-6.9) and acute kidney injury (OR=3.4, 95% CI: 1.3-7.1). Costs of index hospitalization were not significantly different between the 2 cohorts ($30,056 vs. $29,720, P=0.6853). The total costs were also similar throughout the 2-year follow-up period.CONCLUSION: Patients who are HIV positive at the time of LDD surgery are at a higher risk for postoperative central nervous system and renal complications and unplanned readmissions.

  View details for DOI 10.1097/BSD.0000000000001221

  View details for PubMedID 34183544

• 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

  Abstract

  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

• Metastatic Paraganglioma of the Spine With SDHB Mutation: Case Report and Review of the Literature. International journal of spine surgery Jabarkheel, R., Pendharkar, A. V., Lavezo, J. L., Annes, J., Desai, K., Vogel, H., Desai, A. M. 2021; 14 (s4): S37-S45

  Abstract

  Paragangliomas (PGLs) are rare neuroendocrine tumors that can arise from any autonomic ganglion of the body. Most PGLs do not metastasize. Here, we present a rare case of metastatic PGL of the spine in a patient with a germline pathogenic succinate dehydrogenase subunit B (SDHB) mutation.In addition to a case report we provide a literature review of metastatic spinal PGL to highlight the importance of genetic testing and long-term surveillance of these patients.A 45-year-old woman with history of spinal nerve root PGL, 17 years prior, presented with back pain of several months' duration. Imaging revealed multilevel lytic lesions throughout the cervical, thoracic, and lumbar spine as well as involvement of the right mandibular condyle and clavicle. Percutaneous biopsy of the L1 spinal lesion confirmed metastatic PGL and the patient underwent posterior tumor resection and instrumented fusion of T7-T11. Postoperatively the patient was found to have a pathogenic SDHB deletion.Patients with SDHx mutation, particularly SDHB, have increased risk of developing metastatic PGLs. Consequently, these individuals require long-term surveillance given the risk for developing new tumors or disease recurrence, even years to decades after primary tumor resection. Surgical management of spinal metastatic PGL involves correcting spinal instability, minimizing tumor burden, and alleviating epidural cord compression. In patients with metastatic PGL of the spine, genetic testing should be considered.

  View details for DOI 10.14444/7163

  View details for PubMedID 33900943

• Advanced Age Does Not Impact Outcomes After 1-level or 2-level Lateral Lumbar Interbody Fusion. Clinical spine surgery Wadhwa, H., Oquendo, Y. A., Tigchelaar, S. S., Warren, S. I., Koltsov, J. C., Desai, A., Veeravagu, A., Alamin, T. F., Ratliff, J. K., Hu, S. S., Cheng, I. 2021

  Abstract

  This was a retrospective comparative study.The objective of this study was to assess the effect of increased age on perioperative and postoperative complication rates, reoperation rates, and patient-reported pain and disability scores after lateral lumbar interbody fusion (LLIF).LLIF was developed to minimize soft tissue trauma and reduce the risk of vascular injury; however, there is little evidence regarding the effect of advanced age on outcomes of LLIF.Patients who underwent LLIF from 2009 to 2019 at one institution with a minimum 6-month follow-up were retrospectively reviewed. Patients less than 18 years old with musculoskeletal tumor or trauma were excluded. The primary outcome was the preoperative to postoperative change in the Numeric Pain Rating Scale (NPRS) for back pain. Operative time, estimated blood loss, length of stay, perioperative and 90-day complications, unplanned readmissions, reoperations, and change in Oswestry Disability Index were also evaluated. Relationships with age were assessed both with age as a continuous variable and segmenting by age below 70 versus 70+.In total, 279 patients were included. The median age was 65±13 years and 159 (57%) were female. Age was not related to improvements in back NPRS and Oswestry Disability Index. Operative time, estimated blood loss, length of stay, perioperative and 90-day complications, unplanned readmissions, reoperations, and radiographic fusion rate also were not related to age. After multivariable risk adjustment, increasing age was associated with greater improvements in back NPRS. The decrease in back NPRS was 0.68 (95% confidence interval: 0.14, 1.22; P=0.014) points greater for every 10-year increase in age. Age was not associated with rates of complication, readmission, or reoperation.LLIF is a safe and effective procedure in the elderly population. Advanced age is associated with larger improvements in preoperative back pain. Surgeons should consider the benefits of LLIF and other minimally invasive techniques when evaluating elderly candidates for lumbar fusion.Level III.

  View details for DOI 10.1097/BSD.0000000000001270

  View details for PubMedID 34724454

• Defining and Describing Treatment Heterogeneity in New-Onset Idiopathic Lower Back and Extremity Pain Through Reconstruction of Longitudinal Care Sequences. The spine journal : official journal of the North American Spine Society Jin, M. C., Azad, T. D., Fatemi, P., Ho, A. L., Vail, D., Zhang, Y., Feng, A. Y., Kim, L. H., Bentley, J. P., Stienen, M. N., Li, G., Desai, A. M., Veeravagu, A., Ratliff, J. K. 2021

  Abstract

  Despite established guidelines, long-term management of surgically-treated low back pain (LBP) and lower extremity pain (LEP) remains heterogeneous. Understanding care heterogeneity could inform future approaches for standardization of practices.To describe treatment heterogeneity in surgically-managed LBP and LEP.Retrospective study of a nationwide commercial database spanning inpatient and outpatient encounters for enrollees of eligible employer-supplied healthcare plans (2007-2016).A population-based sample of opioid-naïve adult patients with newly-diagnosed LBP or LEP were identified. Inclusion required at least 12-months of pre-diagnosis and post-diagnosis continuous follow-up.Included treatments/evaluations include conservative management (chiropractic manipulative therapy, physical therapy, epidural steroid injections), imaging (x-ray, MRI, CT), pharmaceuticals (opioids, benzodiazepines), and spine surgery (decompression, fusion).Primary outcomes-of-interest were 12-month net healthcare expenditures (inpatient and outpatient) and 12-month opioid usage.Analyses include interrogation of care sequence heterogeneity and temporal trends in sequence-initiating services. Comparisons were conducted in the framework of sequence-specific treatment sequences, which reflect the personalized order of healthcare services pursued by each patient. Outlier sequences characterized by high opioid use and costs were identified from frequently observed surgical treatment sequences using Mahalanobis distance.A total of 2,496,908 opioid-naïve adult patients with newly-diagnosed LBP or LEP were included (29,519 surgical). In the matched setting, increased care sequence heterogeneity was observed in surgical patients (0.51 vs 0.12 previously-unused interventions/studies pursued per month). Early opioid and MRI use has decreased between 2008 and 2015 but is matched by increases in early benzodiazepine and x-ray use. Outlier sequences, characterized by increased opioid use and costs, were found in 5.8% of surgical patients. Use of imaging prior to conservative management was common in patients pursuing outlier sequences compared to non-outlier sequences (96.5% vs 63.8%, p<0.001). Non-outlier sequences were more frequently characterized by early conservative interventions (31.9% vs 7.4%, p<0.001).Surgically-managed LBP and LEP care sequences demonstrate high heterogeneity despite established practice guidelines. Outlier sequences associated with high opioid usage and costs can be identified and are characterized by increased early imaging and decreased early conservative management. Elements that may portend suboptimal longitudinal management could provide opportunities for standardization of patient care.

  View details for DOI 10.1016/j.spinee.2021.05.019

  View details for PubMedID 34033933

• Obesity in Patients Undergoing Lumbar Degenerative Surgery-A Retrospective Cohort Study of Postoperative Outcomes. Spine Varshneya, K., Wadhwa, H., Stienen, M. N., Ho, A. L., Medress, Z. A., Aikin, J., Li, G., Desai, A., Ratliff, J. K., Veeravagu, A. 2021; 46 (17): 1191-1196

  Abstract

  Retrospective cohort studying using a national, administrative database.The aim of this study was to determine the postoperative complications and quality outcomes of patients with and without obesity undergoing surgical management for lumbar degenerative disease (LDD).Obesity is a global epidemic that negatively impacts health outcomes. Characterizing the effect of obesity on LDD surgery is important given the growing elderly obese population.This study identified patients with who underwent surgery for LDD between 2007 and 2016. Patients were stratified based on whether the patient had a concurrent diagnosis of obesity at time of surgery. Propensity score matching (PSM) was then utilized to mitigate intergroup differences between patients with and without obesity. Patients who underwent three or more levels surgical correction, were under the age of 18 years, or those with any previous history of trauma or tumor were excluded from this study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.A total of 67,215 patients underwent primary lumbar degenerative surgery, of which 22,405 (33%) were obese. After propensity score matching, baseline covariates of the two cohorts were similar. The complication rate was 8.3% in the nonobese cohort and 10.4% in the obese cohort (P < 0.0001). Patients with obesity also had longer lengths of stay (2.7 days vs. 2.4 days, P < 0.05), and higher rates of reoperation and readmission at all time-points through the study follow-up period to their nonobese counterparts (P < 0.05). Including payments after discharge, lumbar degenerative surgery in patients with obesity was associated with higher payments throughout the 2-year follow-up period ($68,061 vs. $59,068 P < 0.05).Patients with a diagnosis of obesity at time of LDD surgery are at a higher risk for postoperative complications, reoperation, and readmission.Level of Evidence: 4.

  View details for DOI 10.1097/BRS.0000000000004001

  View details for PubMedID 34384097

• Single vs Multistage Surgical Management of Single and Two-Level Lumbar Degenerative Disease. World neurosurgery Varshneya, K., Wadhwa, H., Stienen, M. N., Ho, A. L., Medress, Z. A., Herrick, D. B., Desai, A., Ratliff, J. K., Veeravagu, A. 2021

  Abstract

  Retrospective cohort studying using a national, administrative database.To determine the postoperative complications and quality outcomes of single and multi-stage surgical management for lumbar degenerative disease (LDD).This study identified patients with who underwent surgery for LDD between 2007 - 2016. Patients were stratified based on whether their surgeon choose to correct their LDD in a single or multistage manner, and these cohorts were mutually exclusive. Propensity score matching (PSM) was then utilized to mitigate intergroup differences between single and multi-stage patients. Patients who underwent three or more levels surgical correction, were under the age of 18 years, or those with any prior history of trauma or tumor were excluded from this study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.A total of 47,190 patients underwent primary surgery for LDD, of which 9,438 (20%) underwent multi-stage surgery. After propensity score matching, baseline covariates of the two cohorts were similar. The complication rate was 6.1% in the single stage cohort and 11.0% in the multistage cohort. Rates of post-hemorrhagic anemia, infection, wound complication, DVT, and hematoma were all higher in the multistage cohort. Lengths of stay, revision, and readmission rates were also significantly higher in the multi-stage cohort. Through 2-years of follow up, multi-stage surgery was associated with higher payments throughout the 2-year follow-up period ($57,036 vs $39,318, p < 0.05).Single stage surgery for lumbar degenerative disc disease demonstrates improved outcomes and lower healthcare utilization. Spine surgeons should carefully consider single-stage surgery when treating patients with less than three-level LDD.

  View details for DOI 10.1016/j.wneu.2021.05.115

  View details for PubMedID 34087456

• Predictive Modeling of Long-Term Opioid and Benzodiazepine Use after Intradural Tumor Resection. The spine journal : official journal of the North American Spine Society Jin, M. C., Ho, A. L., Feng, A. Y., Zhang, Y., Staartjes, V. E., Stienen, M. N., Han, S. S., Veeravagu, A., Ratliff, J. K., Desai, A. M. 2020

  Abstract

  INTRODUCTION: Despite increased awareness of the ongoing opioid epidemic, opioid and benzodiazepine use remain high after spine surgery. In particular, long-term co-prescription of opioids and benzodiazepines have been linked to high risk of overdose-associated death. Tumor patients represent a unique subset of spine surgery patients and few studies have attempted to develop predictive models to anticipate long-term opioid and benzodiazepine use after spinal tumor resection.METHODS: The IBM Watson Health MarketScan Database and Medicare Supplement were assessed to identify admissions for intradural tumor resection between 2007 and 2015. Adult patients were required to have at least 6-months of continuous pre-admission baseline data and 12-months of continuous post-discharge follow-up. Primary outcomes were long-term opioid and benzodiazepine use, defined as at least 6 prescriptions within 12 months. Secondary outcomes were durations of opioid and benzodiazepine prescribing. Logistic regression models, with and without regularization, were trained on an 80% training sample and validated on the withheld 20%.RESULTS: A total of 1,942 patients were identified. The majority of tumors were extramedullary (74.8%) and benign (62.5%). A minority of patients received arthrodesis (9.2%) and most patients were discharged to home (79.1%). Factors associated with post-discharge opioid use duration include tumor malignancy (vs benign, B=19.8 prescribed-days/year, 95% CI 1.1 to 38.5) and intramedullary compartment (vs extramedullary, B=18.1 prescribed-days/year, 95% CI 3.3 to 32.9). Pre- and peri-operative use of prescribed NSAIDs and gabapentin/pregabalin were associated with shorter and longer duration opioid use, respectively. History of opioid and history of benzodiazepine use were both associated with increased post-discharge opioid and benzodiazepine use. Intramedullary location was associated with longer duration post-discharge benzodiazepine use (B=10.3 prescribed-days/year, 95% CI 1.5 to 19.1). Among assessed models, elastic net regularization demonstrated best predictive performance in the withheld validation cohort when assessing both long-term opioid use (AUC=0.748) and long-term benzodiazepine use (AUC=0.704). Applying our model to the validation set, patients scored as low-risk demonstrated a 4.8% and 2.4% risk of long-term opioid and benzodiazepine use, respectively, compared to 35.2% and 11.1% of high-risk patients.CONCLUSIONS: We developed and validated a parsimonious, predictive model to anticipate long-term opioid and benzodiazepine use early after intradural tumor resection, providing physicians opportunities to consider alternative pain management strategies.

  View details for DOI 10.1016/j.spinee.2020.10.010

  View details for PubMedID 33065272

• The Effect of Socioeconomic Status on Age at Diagnosis and Overall Survival in Patients with Intracranial Meningioma. The International journal of neuroscience Brewster, R., Deb, S., Pendharkar, A. V., Ratliff, J., Li, G., Desai, A. 2020: 1–12

  Abstract

  Background: Intracranial meningiomas are the most common primary tumors of the central nervous system. How socioeconomic status (SES) impacts treatment access and outcomes for brain tumor subtypes is an emerging area of research. Few studies have examined the relationship between SES and meningioma survival and management with reference to relevant clinical factors, including age at diagnosis. We studied the independent effects of SES on receiving surgery and survival probability in patients with intracranial meningiomaMethods: 54,282 patients diagnosed with intracranial meningioma between 2003-2012 from the Surveillance, Epidemiology, and End Results (SEER) Program at the National Cancer Institute database were included. Patient SES was divided into tertiles. Patient age groups included "older" (>65, the median patient age) and "younger". Multivariable linear regression and Cox proportional hazards model were used with SAS v9.4. Results were adjusted for race, sex, and tumor grade. Kaplan Meier survival curves were constructed according to SES tertiles and age groups.Results: Meningioma prevalence increased with higher SES tertile. Higher SES tertile was also associated with younger age at diagnosis (OR= 0.890, p <0.05), an increased likelihood of undergoing gross total resection (GTR) (OR =1.112, p<0.05), and a trend towards greater 5-year survival probability (HR =1.773, p=0.0531). Survival probability correlated with younger age at diagnosis (HR =2.597, p<0.001), but not with GTR receipt.Conclusion: The findings from this national longitudinal study on patients with meningioma suggest that SES affects age at diagnosis and treatment access for intracranial meningiomas patients. Further studies are required to understand and address the mechanisms underlying these disparities.

  View details for DOI 10.1080/00207454.2020.1818742

  View details for PubMedID 32878534

• A Comparative Analysis of Patients Undergoing Fusion for Adult Cervical Deformity by Approach Type. Global spine journal Varshneya, K., Medress, Z. A., Stienen, M. N., Nathan, J., Ho, A., Pendharkar, A. V., Loo, S., Aikin, J., Li, G., Desai, A., Ratliff, J. K., Veeravagu, A. 2020: 2192568220915717

  Abstract

  Retrospective cohort study.To provide insight into postoperative complications, short-term quality outcomes, and costs of the surgical approaches of adult cervical deformity (ACD).A national database was queried from 2007 to 2016 to identify patients who underwent cervical fusion for ACD. Patients were stratified by approach type-anterior, posterior, or circumferential. Patients undergoing anterior and posterior approach surgeries were additionally compared using propensity score matching.A total of 6575 patients underwent multilevel cervical fusion for ACD correction. Circumferential fusion had the highest postoperative complication rate (46.9% vs posterior: 36.7% vs anterior: 18.5%, P < .0001). Anterior fusion patients more commonly required reoperation compared with posterior fusion patients (P < .0001), and 90-day readmission rate was highest for patients undergoing circumferential fusion (P < .0001). After propensity score matching, the complication rate remained higher in the posterior, as compared to the anterior fusion group (P < .0001). Readmission rate also remained higher in the posterior fusion group; however, anterior fusion patients were more likely to require reoperation. At index hospitalization, posterior fusion led to 1.5× higher costs, and total payments at 90 days were 1.6× higher than their anterior fusion counterparts.Patients who undergo posterior fusion for ACD have higher complication rates, readmission rates, and higher cost burden than patients who undergo anterior fusion; however, posterior correction of ACD is associated with a lower rate of reoperation.

  View details for DOI 10.1177/2192568220915717

  View details for PubMedID 32875897

• A Comparative Analysis of Patients Undergoing Fusion for Adult Cervical Deformity by Approach Type GLOBAL SPINE JOURNAL Varshneya, K., Medress, Z. A., Stienen, M. N., Nathan, J., Ho, A., Pendharkar, A. V., Loo, S., Aikin, J., Li, G., Desai, A., Ratliff, J. K., Veeravagu, A. 2020

  View details for DOI 10.1177/2192568220915717

  View details for Web of Science ID 000527642400001

• 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

  Abstract

  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

• Postoperative Complication Burden, Revision Risk, and Health Care Use in Obese Patients Undergoing Primary Adult Thoracolumbar Deformity Surgery GLOBAL SPINE JOURNAL Varshneya, K., Pangal, D. J., Stienen, M. N., Ho, A. L., Fatemi, P., Medress, Z. A., Herrick, D. B., Desai, A., Ratliff, J. K., Veeravagu, A. 2020

  View details for DOI 10.1177/2192568220904341

  View details for Web of Science ID 000517915400001

• Postoperative Complication Burden, Revision Risk, and Health Care Use in Obese Patients Undergoing Primary Adult Thoracolumbar Deformity Surgery. Global spine journal Varshneya, K., Pangal, D. J., Stienen, M. N., Ho, A. L., Fatemi, P., Medress, Z. A., Herrick, D. B., Desai, A., Ratliff, J. K., Veeravagu, A. 2020: 2192568220904341

  Abstract

  This is a retrospective cohort study using a nationally representative administrative database.To identify the impact of obesity on postoperative outcomes in patients undergoing thoracolumbar adult spinal deformity (ASD) surgery.The obesity rate in the United States remains staggering, with approximately one-third of all Americans being overweight or obese. However, the impact of elevated body mass index on spine surgery outcomes remains unclear.We queried the MarketScan database to identify patients who were diagnosed with a spinal deformity and underwent ASD surgery from 2007 to 2016. Patients were then stratified by whether or not they were diagnosed as obese at index surgical admission. Propensity score matching (PSM) was then utilized to mitigate intergroup differences between obese and nonobese patients. Patients <18 years and those with any prior history of trauma or tumor were excluded from this study. Baseline demographics and comorbidities, postoperative complication rates, and short- and long-term reoperation rates were determined.A total of 7423 patients met the inclusion criteria of this study, of whom 597 (8.0%) were obese. Initially, patients with obesity had a higher 90-day postoperative complication rate than nonobese patients (46.1% vs 40.8%, P < .05); however, this difference did not remain after PSM. Revision surgery rates after 2 years were similar across the 2 groups following primary surgery (obese, 21.4%, vs nonobese, 22.0%; P = .7588). Health care use occurred at a higher rate among obese patients through 2 years of long-term follow-up (obese, $152 930, vs nonobese, $140 550; P < .05).Patients diagnosed with obesity who underwent ASD surgery did not demonstrate increased rates of complications, reoperations, or readmissions. However, overall health care use through 2 years of follow-up after index surgery was higher in the obesity cohort.

  View details for DOI 10.1177/2192568220904341

  View details for PubMedID 32875891

• Functional Mapping for Glioma Surgery: A Propensity-matched Analysis of Outcomes and Cost. World neurosurgery Pendharkar, A. V., Rezaii, P. G., Ho, A. L., Sussman, E. S., Li, G. n., Desai, A. M. 2020

  Abstract

  To compare clinical outcomes and payments between glioma resections with and without functional mapping.The Thomas Reuters MarketScan national longitudinal database was used to identify patients undergoing resection of supratentorial primary malignant glioma with or without functional mapping between 2007-2016. Patients were stratified into mapped and unmapped (conventional) groups, and subsequently propensity-matched based on demographics, clinical comorbidities, and surgical characteristics (i.e., use of stereotactic navigation, microscope, intratumoral chemotherapy). Outcomes and charges were compared between matched groups using bivariate analyses.A total of 14,037 patients were identified, of which 796 (6.0%) received functional mapping. Propensity-matching (1:1) resulted in 796 mapped patients and 796 propensity-matched controls. Thirty-day postoperative rates of new-onset seizures, cerebral edema, hemorrhage, and neurological deficits were significantly lower for the functional mapping group (all p < 0.05). Functional mapping was also associated with shorter hospital length of stay (p = .0144), lower 30-day rates of emergency department visits (p = .0001) and fewer reoperations (p = .0068). Total costs of initial admission were not significantly different between groups.Intraoperative functional mapping during glioma resection was associated with decreased complications, reoperations, emergency department visits, and shorter lengths of stay. Furthermore, total charges of mapped resections were not significantly different from those of conventional resections. These findings support the utility of functional mapping for resection of supratentorial primary malignant gliomas.

  View details for DOI 10.1016/j.wneu.2020.01.197

  View details for PubMedID 32028000

• Cervical osteochondroma: surgical planning. Spinal cord series and cases Fowler, J. n., Takayanagi, A. n., Siddiqi, I. n., Ghanchi, H. n., Siddiqi, J. n., Veeravagu, A. n., Desai, A. n., Vrionis, F. n., Hariri, O. R. 2020; 6 (1): 44

  Abstract

  Osteochondromas are benign bone tumors which occur as solitary lesions or as part of the syndrome multiple hereditary exostoses. While most osteochondromas occur in the appendicular skeleton, they can also occur in the spine. Most lesions are asymptomatic however some may encroach on the spinal cord or the nerve roots causing neurological symptoms. While most patients with osteochondromas undergo laminectomy without fusion, laminectomy with fusion is indicated in appropriately selected cases of spinal decompression.We present a case of a 32-year-old male with history of multiple hereditary exostoses who presented with symptoms of bilateral upper extremity numbness and complaints of gait imbalance and multiple falls. He reported rapid progression of his symptoms during the 10 days before presentation. Computed tomography of the cervical spine revealed a lobulated bony tumor along the inner margin of the cervical 4 lamina. He underwent cervical 3 and 4 laminectomies, partial cervical 2 and 5 laminectomies and cervical 3-5 mass screw placement. Pathology was consistent with osteochondroma. The patient's symptoms had markedly improved at follow-up.According to our literature review, osteochondromas most commonly occur at cervical 2 and cervical 5. We present a case of an osteochondroma at a less common level, cervical 4. While most osteochondromas are addressed with laminectomy without arthrodesis, the decision of whether arthrodesis is necessary should be considered in all patients with osteochondroma as with any cervical decompression.

  View details for DOI 10.1038/s41394-020-0292-7

  View details for PubMedID 32467563

• 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

• A Predictive-Modeling Based Screening Tool for Prolonged Opioid Use after Surgical Management of Low Back and Lower Extremity Pain. The spine journal : official journal of the North American Spine Society Zhang, Y. n., Fatemi, P. n., Medress, Z. n., Azad, T. D., Veeravagu, A. n., Desai, A. n., Ratliff, J. K. 2020

  Abstract

  Outpatient postoperative pain management in spine patients, specifically involving the use of opioids, demonstrates significant variability.Using preoperative risk factors and 30-day postoperative opioid prescribing patterns, we developed models for predicting long-term opioid use in patients after elective spine surgery.This retrospective cohort study utilizes inpatient, outpatient, and pharmaceutical data from MarketScan databases (Truven Health).In all, 19,317 patients who were newly diagnosed with low back or lower extremity pain (LBP or LEP) between 2008 and 2015 and underwent thoracic or lumbar surgery within one year after diagnosis were enrolled. Some patients initiated opioids after diagnosis but all patients were opioid-naïve prior to the diagnosis.Long-term opioid use was defined as filling ≥180 days of opioids within one year after surgery.Using demographic variables, medical and psychiatric comorbidities, preoperative opioid use, and 30-day postoperative opioid use, we generated seven models on 80% of the dataset and tested the models on the remaining 20%. We used three regression-based models (full logistic regression, stepwise logistic regression, least absolute shrinkage and selection operator [LASSO]), support vector machine, two tree-based models (random forest, stochastic gradient boosting), and time-varying convolutional neural network. Area under the curve (AUC), Brier index, sensitivity, and calibration curves were used to assess the discrimination and calibration of the models.We identified 903 (4.6%) of patients who met criteria for long-term opioid use. The regression-based models demonstrated the highest AUC, ranging from 0.835 to 0.847, and relatively high sensitivities, predicting between 74.9-76.5% of the long-term opioid use patients in the test dataset. The three strongest positive predictors of long-term opioid use were high preoperative opioid use (OR 2.70; 95% CI 2.27-3.22), number of days with active opioid prescription between postoperative days 15-30 (OR 1.10; 95% CI 1.07-1.12), and number of dosage increases between postoperative day 15-30 (OR 1.71, 95% CI 1.41-2.08). The strongest negative predictors were number of dosage decreases in the 30-day postoperative period.We evaluated several predictive models for postoperative long-term opioid use in a large cohort of patients with LBP or LEP who underwent surgery. A regression-based model with high sensitivity and AUC is provided online to screen patients for high risk of long-term opioid use based on preoperative risk factors and opioid prescription patterns in the first 30 days after surgery. It is hoped that this work will improve identification of patients at high risk of prolonged opioid use and enable early intervention and counseling.

  View details for DOI 10.1016/j.spinee.2020.05.098

  View details for PubMedID 32445803

• Conventional Versus Stereotactic Image Guided Pedicle Screw Placement During Spinal Deformity Correction: A Retrospective Propensity Score-Matched Study of a National Longitudinal Database. The International journal of neuroscience Rezaii, P. G., Pendharkar, A. V., Ho, A. L., Sussman, E. S., Veeravagu, A. n., Ratliff, J. K., Desai, A. M. 2020: 1–13

  Abstract

  Purpose/aim: To compare complications, readmissions, revisions, and payments between navigated and conventional pedicle screw fixation for treatment of spine deformity.Methods: The Thomson Reuters MarketScan national longitudinal database was used to identify patients undergoing osteotomy, posterior instrumentation, and fusion for treatment of spinal deformity with or without image-guided navigation between 2007-2016. Conventional and navigated groups were propensity-matched (1:1) to normalize differences between demographics, comorbidities, and surgical characteristics. Clinical outcomes and charges were compared between matched groups using bivariate analyses.Results: A total of 4,604 patients were identified as having undergone deformity correction, of which 286 (6.2%) were navigated. Propensity-matching resulted in a total of 572 well-matched patients for subsequent analyses, of which half were navigated. Rate of mechanical instrumentation-related complications was found to be significantly lower for navigated procedures (p = 0.0371). Navigation was also associated with lower rates of 90-day unplanned readmissions (p = 0.0295), as well as 30- and 90-day postoperative revisions (30-day: p = 0.0304, 90-day: p = 0.0059). Hospital, physician, and total payments favored the conventional group for initial admission (p = 0.0481, 0.0001, 0.0019, respectively); however, when taking into account costs of readmissions, hospital payments became insignificantly different between the two groups.Conclusions: Procedures involving image-guided navigation resulted in decreased instrumentation-related complications, unplanned readmissions, and postoperative revisions, highlighting its potential utility for the treatment of spine deformity. Future advances in navigation technologies and methodologies can continue to improve clinical outcomes, decrease costs, and facilitate widespread adoption of navigation for deformity correction.

  View details for DOI 10.1080/00207454.2020.1763343

  View details for PubMedID 32364414

• 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

  Abstract

  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

• Adverse Events and Bundled Costs after Cranial Neurosurgical Procedures: Validation of the LACE Index Across 40,431 Admissions and Development of the LACE-Cranial Index. World neurosurgery Jin, M. C., Wu, A. n., Medress, Z. A., Parker, J. J., Desai, A. n., Veeravagu, A. n., Grant, G. A., Li, G. n., Ratliff, J. K. 2020

  Abstract

  Anticipating post-discharge complications following neurosurgery remains difficult. The LACE index, based on four hospitalization descriptors, stratifies patients by risk of 30-day post-discharge adverse events but has not been validated in a procedure-specific manner in neurosurgery. Our study sought to explore the utility of the LACE index in cranial neurosurgery population and to develop an enhanced model, LACE-Cranial.The Optum Clinformatics Database was used to identify cranial neurosurgery admissions (2004-2017). Procedures were grouped as trauma/hematoma/ICP, open vascular, functional/pain, skull base, tumor, or endovascular. Adverse events were defined as post-discharge death/readmission. LACE-Cranial was developed using a logistic regression framework incorporating an expanded feature set in addition to the original LACE components.A total of 40,431 admissions were included. Predictions of 30-day readmissions was best for skull-base (AUC=0.636) and tumor (AUC=0.63) admissions but was generally poor. Predictive ability of 30-day mortality was best for functional/pain admissions (AUC=0.957) and poorest for trauma/hematoma/ICP admissions (AUC=0.613). Across procedure types except for functional/pain, a high-risk LACE score was associated with higher post-discharge bundled payment costs. Incorporating features identified to contribute independent predictive value, the LACE-Cranial model achieved procedure-specific 30-day mortality AUCs ranging from 0.904 to 0.98. Prediction of 30-day and 90-day readmissions was also improved, with tumor and skull base cases achieving 90-day readmission AUCs of 0.718 and 0.717, respectively.While the unmodified LACE index demonstrates inconsistent classification performance, the enhanced LACE-Cranial model offers excellent prediction of short-term post-discharge mortality across procedure groups and significantly improved anticipation of short-term post-discharge readmissions.

  View details for DOI 10.1016/j.wneu.2020.10.103

  View details for PubMedID 33127572

• Opioid Use in Adults with Low Back or Lower Extremity Pain who Undergo Spine Surgical Treatment within One Year of Diagnosis. Spine Fatemi, P. n., Zhang, Y. n., Ho, A. n., Lama, R. n., Jin, M. n., Veeravagu, A. n., Desai, A. n., Ratliff, J. K. 2020

  Abstract

  Retrospective longitudinal cohort.We investigated opioid prescribing patterns amongst adults in the United States diagnosed with low back or lower extremity pain (LBP/LEP) who underwent spine surgery.Opioid-based treatment of LBP/LEP and postsurgical pain have separately been associated with chronic opioid use, but a combined and large-scale cohort study is missing.This study utilizes commercial inpatient, outpatient, and pharmaceutical insurance claims. Between 2008 and 2015, patients without prior prescription opioids with a new diagnosis of LBP/LEP who underwent surgery within one year after diagnosis were enrolled. Opioid prescribing patterns after LBP/LEP diagnosis and after surgery were evaluated. All patients had one-year postoperative follow-up. Low and high frequency (≥6 refills in 12 months) opioid prescription groups were identified.25,506 patients without prior prescription opioids were diagnosed with LBP/LEP and underwent surgery within one year of diagnosis. After LBP/LEP diagnosis, 18,219 (71.4%) were prescribed opioids while 7,287 (28.6%) were not. After surgery, 2,952 (11.6%) were prescribed opioids with high frequency and 22,554 (88.4%) with low frequency. Among patients prescribed opioids prior to surgery, those with high frequency prescriptions were more likely to continue this pattern postoperatively than those with low frequency prescriptions preoperatively (OR:2.15, 95% CI:1.97-2.34). For those prescribed opioids preoperatively, average daily morphine milligram equivalent (MME) decreased after surgery (by 2.62 in decompression alone cohort and 0.25 in arthrodesis cohort, p < 0.001). Postoperative low-frequency patients were more likely than high-frequency patients to discontinue opioids one-year after surgery (OR:3.78, 95% CI:3.59-3.99). Postoperative high-frequency patients incurred higher cost than low-frequency patients. Postoperative high-frequency prescribing varied widely across states (4.3%-20%).A stepwise association exists between opioid use after LEP or LBP diagnosis and frequency and duration of opioid prescriptions after surgery. Simultaneously, the strength of prescriptions as measured by MME decreased following surgery.3.

  View details for DOI 10.1097/BRS.0000000000003663

  View details for PubMedID 32833930

• Normative data of a smartphone app-based 6-minute walking test, test-retest reliability, and content validity with patient-reported outcome measures. Journal of neurosurgery. Spine Tosic, L. n., Goldberger, E. n., Maldaner, N. n., Sosnova, M. n., Zeitlberger, A. M., Staartjes, V. E., Gadjradj, P. S., Eversdijk, H. A., Quddusi, A. n., Gandía-González, M. L., Sayadi, J. J., Desai, A. n., Regli, L. n., Gautschi, O. P., Stienen, M. N. 2020: 1–10

  Abstract

  The 6-minute walking test (6WT) is used to determine restrictions in a subject's 6-minute walking distance (6WD) due to lumbar degenerative disc disease. To facilitate simple and convenient patient self-measurement, a free and reliable smartphone app using Global Positioning System coordinates was previously designed. The authors aimed to determine normative values for app-based 6WD measurements.The maximum 6WD was determined three times using app-based measurement in a sample of 330 volunteers without previous spine surgery or current spine-related disability, recruited at 8 centers in 5 countries (mean subject age 44.2 years, range 16-91 years; 48.5% male; mean BMI 24.6 kg/m2, range 16.3-40.2 kg/m2; 67.9% working; 14.2% smokers). Subjects provided basic demographic information, including comorbidities and patient-reported outcome measures (PROMs): visual analog scale (VAS) for both low-back and lower-extremity pain, Core Outcome Measures Index (COMI), Zurich Claudication Questionnaire (ZCQ), and subjective walking distance and duration. The authors determined the test-retest reliability across three measurements (intraclass correlation coefficient [ICC], standard error of measurement [SEM], and mean 6WD [95% CI]) stratified for age and sex, and content validity (linear regression coefficients) between 6WD and PROMs.The ICC for repeated app-based 6WD measurements was 0.89 (95% CI 0.87-0.91, p < 0.001) and the SEM was 34 meters. The overall mean 6WD was 585.9 meters (95% CI 574.7-597.0 meters), with significant differences across age categories (p < 0.001). The 6WD was on average about 32 meters less in females (570.5 vs 602.2 meters, p = 0.005). There were linear correlations between average 6WD and VAS back pain, VAS leg pain, COMI Back and COMI subscores of pain intensity and disability, ZCQ symptom severity, ZCQ physical function, and ZCQ pain and neuroischemic symptoms subscores, as well as with subjective walking distance and duration, indicating that subjects with higher pain, higher disability, and lower subjective walking capacity had significantly lower 6WD (all p < 0.001).This study provides normative data for app-based 6WD measurements in a multicenter sample from 8 institutions and 5 countries. These values can now be used as reference to compare 6WT results and quantify objective functional impairment in patients with degenerative diseases of the spine using z-scores. The authors found a good to excellent test-retest reliability of the 6WT app, a low area of uncertainty, and high content validity of the average 6WD with commonly used PROMs.

  View details for DOI 10.3171/2020.3.SPINE2084

  View details for PubMedID 32470938

• Adult Spinal Deformity Surgery in Patients With Movement Disorders: A Propensity-matched Analysis of Outcomes and Cost. Spine Varshneya, K. n., Azad, T. D., Pendharkar, A. V., Desai, A. n., Cheng, I. n., Karikari, I. n., Ratliff, J. K., Veeravagu, A. n. 2020; 45 (5): E288–E295

  Abstract

  This was a retrospective study using national administrative data from the MarketScan database.To investigate the complication rates, quality outcomes, and costs in a nationwide cohort of patients with movement disorders (MD) who undergo spinal deformity surgery.Patients with MD often present with spinal deformities, but their tolerance for surgical intervention is unknown.The MarketScan administrative claims database was queried to identify adult patients with MD who underwent spinal deformity surgery. A propensity-score match was conducted to create two uniform cohorts and mitigate interpopulation confounders. Perioperative complication rates, 90-day postoperative outcomes, and total costs were compared between patients with MD and controls.A total of 316 patients with MD (1.7%) were identified from the 18,970 undergoing spinal deformity surgery. The complication rate for MD patients was 44.6% and for the controls 35.6% (P = 0.009). The two most common perioperative complications were more likely to occur in MD patients, acute-posthemorrhagic anemia (26.9% vs. 20.8%, P < 0.05) and deficiency anemia (15.5% vs. 8.5%, P < 0.05). At 90 days, MD patients were more likely to be readmitted (17.4% vs. 13.2%, P < 0.05) and have a higher total cost ($94,672 vs. $85,190, P < 0.05). After propensity-score match, the overall complication rate remained higher in the MD group (44.6% vs. 37.6%, P < 0.05). 90-day readmissions and costs also remained significantly higher in the MD cohort. Multivariate modeling revealed MD was an independent predictor of postoperative complication and inpatient readmission. Subgroup analysis revealed that Parkinson disease was an independent predictor of inpatient readmission, reoperation, and increased length of stay.Patients with MD who undergo spinal deformity surgery may be at risk of higher rate of perioperative complications and 90-day readmissions compared with patients without these disorders.3.

  View details for DOI 10.1097/BRS.0000000000003251

  View details for PubMedID 32045403

• Improving the Patient-Physician Relationship in the Digital Era - Transformation From Subjective Questionnaires Into Objective Real-Time and Patient-Specific Data Reporting Tools. Neurospine Maldaner, N., Desai, A., Gautschi, O. P., Regli, L., Ratliff, J. K., Park, J., Stienen, M. N. 2019; 16 (4): 712–14

  View details for DOI 10.14245/ns.1938400.200

  View details for PubMedID 31905462

• 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

  Abstract

  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

  View details for DOI 10.1177/2192568219889363

  View details for Web of Science ID 000498682300001

• Outcomes After Cervical Disc Arthroplasty Versus Stand-Alone Anterior Cervical Discectomy and Fusion: A Meta-Analysis GLOBAL SPINE JOURNAL Gendreau, J. L., Kim, L. H., Prins, P. N., D'Souza, M., Rezaii, P., Pendharkar, A., Sussman, E. S., Ho, A. L., Desai, A. M. 2019

  View details for DOI 10.1177/2192568219888448

  View details for Web of Science ID 000498222100001

• Outcomes After Cervical Disc Arthroplasty Versus Stand-Alone Anterior Cervical Discectomy and Fusion: A Meta-Analysis. Global spine journal Gendreau, J. L., Kim, L. H., Prins, P. N., D'Souza, M., Rezaii, P., Pendharkar, A. V., Sussman, E. S., Ho, A. L., Desai, A. M. 2019: 2192568219888448

  Abstract

  Systemic review and meta-analysis.To review and compare surgical outcomes for patients undergoing stand-alone anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA) for the treatment of cervical spine disease.A systematic search was performed on PubMed, Medline, and the Cochrane Library. Comparative trials measuring outcomes of patients undergoing CDA and stand-alone ACDF for degenerative spine disease in the last 10 years were selected for inclusion. After data extraction and quality assessment, statistical analysis was performed with R software metafor package. The random-effects model was used if there was heterogeneity between studies; otherwise, the fixed-effects model was used.In total, 12 studies including 859 patients were selected for inclusion in the meta-analysis. Patients undergoing stand-alone ACDF had a statistically significant increase in postoperative segmental angles (mean difference 0.85° [95% confidence interval = 0.35° to 1.35°], P = .0008). Patients undergoing CDA had a decreased rate of developing adjacent segmental degeneration (risk ratio = 0.56 [95% confidence interval = -0.06 to 1.18], P = .0745). Neck Disability Index, Japanese Orthopedic Association score, Visual Analogue Scale of the arm and neck, as well as postoperative cervical angles were similar between the 2 treatments.When compared with CDA, stand-alone ACDF offers similar clinical outcomes for patients and leads to increased postoperative segmental angles. We encourage further blinded randomized trials to compare rates of adjacent segmental degeneration and other postoperative outcomes between these 2 treatments options.

  View details for DOI 10.1177/2192568219888448

  View details for PubMedID 32875831

• Propensity-matched Comparison of Outcomes and Costs After Macroscopic and Microscopic Anterior Cervical Corpectomy Using a National Longitudinal Database. Spine Ho, A. L., Rezaii, P. G., Pendharkar, A. V., Sussman, E. S., Veeravagu, A., Ratliff, J. K., Desai, A. M. 2019; 44 (21): E1281–E1288

  Abstract

  STUDY DESIGN: A retrospective analysis of national longitudinal database.OBJECTIVE: The aim of this study was to examine the outcomes and cost-effectiveness of operating microscope utilization in anterior cervical corpectomy (ACC).SUMMARY OF BACKGROUND DATA: The operating microscope allows for superior visualization and facilitates ACC with less manipulation of tissue and improved decompression of neural elements. However, many groups report no difference in outcomes with increased cost associated with microscope utilization.METHODS: A longitudinal database (MarketScan) was utilized to identify patients undergoing ACC with or without microscope between 2007 and 2016. Propensity matching was performed to normalize differences between the two cohorts. Outcomes and costs were subsequently compared.RESULTS: A total of 11,590 patients were identified for the "macroscopic" group, while 4299 patients were identified for the "microscopic" group. For the propensity-matched analysis, 4298 patients in either cohort were successfully matched according to preoperative characteristics. Hospital length of stay was found to be significantly longer in the macroscopic group than the microscopic group (1.86 nights vs. 1.56 nights, P < 0.0001). Macroscopic ACC patients had an overall higher rate of readmissions [30-day: 4.2% vs. 3.2%, odds ratio (OR) = 0.76 (0.61-0.96), P = 0.0223; 90-day: 7.0% vs. 5.9%, OR = 0.82 (0.69-0.98), P = 0.0223]. Microscopic ACC patients had a higher rate of discharge to home [86.6% vs. 92.5%, OR = 1.91 (1.65-2.21), P < 0.0001] and lower rates of new referrals to pain management [1.0% vs. 0.4%, OR = 0.42 (0.23-0.74), P = 0.0018] compared with macroscopic ACC. Postoperative complication rate was not found to be significantly different between the groups. Finally, total initial admission charges were not significantly different between the macroscopic and microscopic groups ($30,175 vs. $29,827, P = 0.9880).CONCLUSION: The present study suggests that the use of the operating microscope for ACC is associated with decreased length of stay, readmissions, and new referrals to pain management, as well as higher rate of discharge to home.LEVEL OF EVIDENCE: 3.

  View details for DOI 10.1097/BRS.0000000000003147

  View details for PubMedID 31634304

• Conventional Versus Stereotactic Image-guided Pedicle Screw Placement During Posterior Lumbar Fusions: A Retrospective Propensity Score-matched Study of a National Longitudinal Database. Spine Pendharkar, A. V., Rezaii, P. G., Ho, A. L., Sussman, E. S., Veeravagu, A., Ratliff, J. K., Desai, A. M. 2019; 44 (21): E1272–E1280

  Abstract

  STUDY DESIGN: Retrospective 1:1 propensity score-matched analysis on a national longitudinal database between 2007 and 2016.OBJECTIVE: The aim of this study was to compare complication rates, revision rates, and payment differences between navigated and conventional posterior lumbar fusion (PLF) procedures with instrumentation.SUMMARY OF BACKGROUND DATA: Stereotactic navigation techniques for spinal instrumentation have been widely demonstrated to improve screw placement accuracies and decrease perforation rates when compared to conventional fluoroscopic and free-hand techniques. However, the clinical utility of navigation for instrumented PLF remains controversial.METHODS: Patients who underwent elective laminectomy and instrumented PLF were stratified into "single level" and "3- to 6-level" cohorts. Navigation and conventional groups within each cohort were balanced using 1:1 propensity score matching, resulting in 1786 navigated and conventional patients in the single-level cohort and 2060 in the 3 to 6 level cohort. Outcomes were compared using bivariate analysis.RESULTS: For the single-level cohort, there were no significant differences in rates of complications, readmissions, revisions, and length of stay between the navigation and conventional groups. For the 3- to 6-level cohort, length of stay was significantly longer in the navigation group (P < 0.0001). Rates of readmissions were, however, greater for the conventional group (30-day: P = 0.0239; 90-day: P = 0.0449). Overall complications were also greater for the conventional group (P = 0.0338), whereas revision rate was not significantly different between the 2 groups. Total payments were significantly greater for the navigation group in both the single level and 3- to 6-level cohorts (P < 0.0001).CONCLUSION: Although use of navigation for 3- to 6-level instrumented PLF was associated with increased length of stay and payments, the concurrent decreased overall complication and readmission rates alluded to its potential clinical utility. However, for single-level instrumented PLF, no differences in outcomes were found between groups, suggesting that the value in navigation may lie in more complex procedures.LEVEL OF EVIDENCE: 3.

  View details for DOI 10.1097/BRS.0000000000003130

  View details for PubMedID 31634303

• Trends in Anterior Lumbar Interbody Fusion in the United States: A MarketScan Study From 2007 to 2014. Clinical spine surgery Varshneya, K., Medress, Z. A., Jensen, M., Azad, T. D., Rodrigues, A., Stienen, M. N., Desai, A., Ratliff, J. K., Veeravagu, A. 2019

  Abstract

  BACKGROUND: Although the incidence of spinal fusions has increased significantly in the United States over the last quarter century, national trends of anterior lumbar interbody fusion (ALIF) utilization are not known.PURPOSE: The objective of this study was to characterize trends, clinical characteristics, risk factors associated with, and outcomes of ALIF in the United States.STUDY DESIGN: This was an epidemiological study using national administrative data from the MarketScan database.METHODS: Using a large administrative database, we identified adults who underwent ALIF in the United States from 2007 to 2014. The incidence of ALIF was studied longitudinally over time and across geographic regions in the United States. Data related to postoperative complications, length of stay, readmission, and cost were collected.RESULTS: We identified 49,945 patients that underwent ALIF in the United States between 2007 and 2014. The total number of ALIF procedures increased from 3650 in 2007 to 6151 in 2014, accounting for an average increase of 24.07% annually. The Southern United States performed the highest number of ALIFs. The most common conditions treated were degenerative disc disease and spondylolisthesis. Over one third of patients (34.6%) underwent multilevel fusion. The most common complications were iron deficiency anemia, urinary tract infections, and pulmonary complications. Hospital and physician pay increased significantly during the study period.CONCLUSIONS: For the first time in our knowledge, we identified national trends in ALIF utilization, outcomes, and cost using a large administrative database. Our study reaffirms prior work that has demonstrated low rates of complications, mortality, and readmission following ALIF.LEVEL OF EVIDENCE: Level III.

  View details for DOI 10.1097/BSD.0000000000000904

  View details for PubMedID 31609798

• Objective measures of functional impairment for degenerative diseases of the lumbar spine: a systematic review of the literature SPINE JOURNAL Stienen, M. N., Ho, A. L., Staartjes, V. E., Maldaner, N., Veeravagu, A., Desai, A., Gautschi, O. P., Bellut, D., Regli, L., Ratliff, J. K., Park, J. 2019; 19 (7): 1276–93

  View details for DOI 10.1016/j.spinee.2019.02.014

  View details for Web of Science ID 000471904100017

• Patient Satisfaction and Press Ganey Scores for Spine Versus Nonspine Neurosurgery Clinics. Clinical spine surgery Chen, Y., Johnson, E., Montalvo, C., Stratford, S., Veeravagu, A., Tharin, S., Desai, A., Ratliff, J., Shuer, L., Park, J. 2019

  Abstract

  STUDY DESIGN: Retrospective survey review.OBJECTIVE: We seek to evaluate satisfaction scores in patients seen in neurosurgical spine versus neurosurgical nonspine clinics.SUMMARY OF BACKGROUND DATA: The Press Ganey survey is a well-established metric for measuring hospital performance and patient satisfaction. These measures have important implications in setting hospital policy and guiding interventions to improve patient perceptions of care.METHODS: Retrospective Press Ganey survey review was performed to identify patient demographics and patient visit characteristics from January 1st, 2012 to October 10th, 2017 at Stanford Medical Center. A total of 40 questions from the Press Ganey survey were investigated and grouped in categories addressing physician and nursing care, personal concerns, admission, room, meal, operating room, treatment and discharge conditions, visitor accommodations and overall clinic assessment. Raw ordinal scores were converted to continuous scores of 100 for unpaired student t test analysis. We identified 578 neurosurgical spine clinic patients and 1048 neurosurgical nonspine clinic patients.RESULTS: Spine clinic patients reported lower satisfaction scores in aggregate (88.2 vs. 90.1; P=0.0014), physician (89.5 vs. 92.6; P=0.0002) and nurse care (91.3 vs. 93.4; P=0.0038), personal concerns (88.2 vs. 90.9; P=0.0009), room (81.0 vs. 83.1; P=0.0164), admission (90.8 vs. 92.6; P=0.0154) and visitor conditions (87.0 vs. 89.2; P=0.0148), and overall clinic assessment (92.9 vs. 95.5; P=0.005).CONCLUSIONS: This study is the first to evaluate the relationship between neurosurgical spine versus nonspine clinic with regards to patient satisfaction. The spine clinic cohort reported less satisfaction than the nonspine cohort in all significant questions on the Press Ganey survey. Our findings suggest that efforts should be made to further study and improve patient satisfaction in spine clinics.LEVEL OF EVIDENCE: Level III.

  View details for DOI 10.1097/BSD.0000000000000825

  View details for PubMedID 30969193

• Socioeconomic Predictors of Surgical Resection and Survival for Patients With Osseous Spinal Neoplasms CLINICAL SPINE SURGERY Deb, S., Brewster, R., Pendharkar, A., Veeravagu, A., Ratliff, J., Desai, A. 2019; 32 (3): 125–31

  View details for DOI 10.1097/BSD.0000000000000738

  View details for Web of Science ID 000464982800008

• Socioeconomic Predictors of Pituitary Surgery. Cureus Deb, S., Vyas, D. B., Pendharkar, A. V., Rezaii, P. G., Schoen, M. K., Desai, K., Gephart, M. H., Desai, A. 2019; 11 (1): e3957

  Abstract

  There exists a lack of data on the effect of socioeconomic status (SES) on outcomes for pituitary tumors, which have been associated with significant morbidity. The goal of this population-level study is to investigate the role of SES on receiving treatment and survival in patients with pituitary tumors.The Surveillance, Epidemiology, and End Results (SEER) program database from the National Cancer Institute was used to identify patients diagnosed with pituitary tumors between 2003 and 2012. SES was determined using a validated composite index. Race was categorized as Caucasian and non-Caucasian. Treatment received included surgery, radiation, and radiation with surgery. Odds of receiving surgery and survival probability were analyzed using multivariate logistic regression and Cox proportional hazards model, respectively.A total of 25,802 patients with pituitary tumors were identified for analysis. High SES tertile (odds ratio (OR) = 1.095; 95% confidence interval (CI) [1.059, 1.132]) and quintile (OR = 1.052; 95% CI [1.031, 1.072]) were associated with higher odds of receiving surgery (p<0.0001). Caucasian patients had higher odds of receiving surgery when compared to non-Caucasian patients (OR = 1.064; 95% CI [1.000, 1.133]; p<0.05). Neither SES nor race were significant predictors of survival probability.Socioeconomic status and race were found to be associated with higher odds of receiving surgery for pituitary tumors, and thus serve as independent predictors of surgical management. Further studies are required to investigate possible causes for these findings.

  View details for DOI 10.7759/cureus.3957

  View details for PubMedID 30956910

  View details for PubMedCentralID PMC6436671

• Outcomes and costs following Ommaya placement with thrombocytopenia among US cancer patients. World neurosurgery Zhang, M. n., Zhang, Y. n., Zheng, E. n., Gephart, M. H., Veeravagu, A. n., Desai, A. n., Ratliff, J. K., Li, G. n. 2019

  Abstract

  Placement of Ommaya reservoirs for administration of intrathecal chemotherapy may be complicated by comorbid thrombocytopenia among patients with hematologic or leptomeningeal disease. Aggregated data on risks of Ommaya placement among thrombocytopenic patients is lacking. This study assesses complications, revision rates, and costs associated with Ommaya placement among patients with thrombocytopenia in a large population sample.Using a national administrative database, this retrospective study identifies a cohort of adult cancer patients who underwent Ommaya placement between 2007 and 2016. Preoperative thrombocytopenia was defined as diagnosis of secondary thrombocytopenia, bleeding event, procedure to control bleeding, or platelet transfusion, within 30 days prior to index admission. Univariate and multivariate analyses were performed to assess costs, 30-day complications, readmissions, and revisions among patients with and without preoperative thrombocytopenia.The analytic cohort included 1652 patients, of whom 29.3% met criteria for preoperative thrombocytopenia. In-hospital mortality rates were 7.7% among thrombocytopenic patients vs. 1.2% among non-thrombocytopenic patients (p < 0.001). Preoperative thrombocytopenia was associated with 14.5 times greater hazard of intracranial hemorrhage within 30 days following Ommaya placement, occurring in 25.6% vs. 2.0% of thrombocytopenic and non-thrombocytopenic patients, respectively (p < 0.014). Revision rates did not differ significantly between thrombocytopenic and non-thrombocytopenic patients. Thrombocytopenia was associated with longer length of stay (7.4 vs 13.9 days, p < 0.001) and additional $10,000 per patient in costs of index hospitalization (p < 0.001).This is the largest study to date documenting costs and complication rates of Ommaya placement in patients with and without thrombocytopenia.

  View details for DOI 10.1016/j.wneu.2019.12.063

  View details for PubMedID 31866457

• 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

  Abstract

  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

• Analysis of Outcomes and Cost of Inpatient and Ambulatory Anterior Cervical Disk Replacement Using a State-level Database. Clinical spine surgery Purger, D. A., Pendharkar, A. V., Ho, A. L., Sussman, E. S., Veeravagu, A. n., Ratliff, J. K., Desai, A. M. 2019

  Abstract

  Outpatient cervical artificial disk replacement (ADR) is a promising candidate for cost reduction. Several studies have demonstrated low overall complications and minimal readmission in anterior cervical procedures.The objective of this study was to compare clinical outcomes and cost associated between inpatient and ambulatory setting ADR.Outcomes and cost were retrospectively analyzed for patients undergoing elective ADR in California, Florida, and New York from 2009 to 2011 in State Inpatient and Ambulatory Databases.A total of 1789 index ADR procedures were identified in the inpatient database (State Inpatient Databases) compared with 370 procedures in the ambulatory cohort (State Ambulatory Surgery and Services Databases). Ambulatory patients presented to the emergency department 19 times (5.14%) within 30 days of the index procedure compared with 4.2% of inpatients. Four unique patients underwent readmission within 30 days in the ambulatory ADR cohort (1% total) compared with 2.2% in the inpatient ADR group. No ambulatory ADR patients underwent a reoperation within 30 days. Of the inpatient ADR group, 6 unique patients underwent reoperation within 30 days (0.34%, Charlson Comorbidity Index zero=0.28%, Charlson Comorbidity Index>0=0.6%). There was no significant difference in emergency department visit rate, inpatient readmission rate, or reoperation rates within 30 days of the index procedure between outpatient or inpatient ADR. Outpatient ADR is noninferior to inpatient ADR in all clinical outcomes. The direct cost was significantly lower in the outpatient ADR group ($11,059 vs. 17,033; P<0.001). The 90-day cumulative charges were significantly lower in the outpatient ADR group (mean $46,404.03 vs. $80,055; P<0.0001).ADR can be performed in an ambulatory setting with comparable morbidity, readmission rates, and lower costs, to inpatient ADR.

  View details for DOI 10.1097/BSD.0000000000000840

  View details for PubMedID 31180992

• Clinical efficacy of frameless stereotactic radiosurgery in the management of spinal metastases from thyroid carcinoma. Spine Hariri, O. n., Takayanagi, A. n., Lischalk, J. n., Desai, K. n., Florence, T. J., Yazdian, P. n., Chang, S. D., Vrionis, F. n., Adler, J. R., Quadri, S. A., Desai, A. n. 2019

  Abstract

  MINI: Study evaluates the efficacy of CyberKnife® (CK) SRS for thyroid spinal metastases (SM). Patients with SMs from thyroid carcinoma that were treated with CK SRS between 2003 and 2013were identified. CK can be safely used to treat SMs from thyroid cancer with a high rate of local control.A retrospective data review.To evaluate the efficacy of CyberKnife® SRS for thyroid SMs.Thyroid carcinoma is an infrequent cause of spinal metastasis (SM). The absolute efficacy of stereotactic radiosurgery (SRS) generally and CyberKnife® (CK) in particular remains poorly characterized for thyroid SM. The current study is the first to specifically evaluate the efficacy of CyberKnife® SRS for thyroid SMs.A retrospective review of patients at our institution between 2003 and 2013 was done. Details about tumor location, radiographic findings before and after CK SRS, tumor recurrence, prescription isodose level, total and maximum dose, number of fractions, and gross tumor volume coverage were similarly collected. For comparison with other studies, the biologically effective dose (BED) and the equivalent total dose in 2Gy fractions (EQD2) were calculated. Each patient was assessed for survival and local disease control from the time of the first CK session and survival analysis was carried out using the Kaplan-Meier method. Risk factors for local failure were assessed using multivariate logistic regression.A total of 12 patients with 32 spinal metastases from thyroid carcinoma that were treated with CK SRS were identified. Survival for 1, 2, and 3 years was 55%, 44%, and 33%, and local control was 67%, 56%, and 34% respectively. The study found that the single strongest factor associated with local control was prior radiotherapy (β-coefficient -27.72, p = 0.01). No complications occurred in the immediate or late follow-up period.This was the first study to specifically investigate the efficacy of CK for treatment of thyroid SMs. Our findings suggest that CK can be safely used to treat spinal SMs from thyroid cancer and is associated with a high rate of local control.4.

  View details for DOI 10.1097/BRS.0000000000003087

  View details for PubMedID 31261273

• Transoral Endoscopic Resection of High Cervical Osteophytes with Long- Term Symptom Resolution: Case Series, Imaging, and Literature Review WORLD NEUROSURGERY Jabarkheel, R., Chen, Y., Xu, L., Yan, C. H., Patel, Z. M., Desai, A. M. 2018; 120: 240–43

  View details for DOI 10.1016/j.wneu.2018.08.188

  View details for Web of Science ID 000450668300193

• Trans-Oral Endoscopic Resection of High Cervical Osteophytes with Long-term Symptom Resolution: Case Series, Imaging, and Literature Review. World neurosurgery Jabarkheel, R., Chen, Y., Xu, L., Yan, C. H., Patel, Z. M., Desai, A. M. 2018

  Abstract

  BACKGROUND: Anterior cervical osteophytes (ACOs) are a common radiological finding in the elderly; rarely, they can cause dysphagia, dysphonia, and dyspnea. Symptomatic ACOs are most commonly found between C4-C7 and much less commonly at higher cervical levels. Here, we present a case series, with an example case of a 57-year-old woman with high cervical osteophytes at C1-C2 causing globus sensation, dysphagia, and dysphonia. Additionally, we provide a literature review regarding the etiology, diagnosis, and treatment of ACOs with a focus on management of high ACOs.CASE DESCRIPTION: A 57 year-old smoker with a history of chronic neck pain and previous cervical spinal instrumentation presented with several months of globus sensation, dysphagia, and dysphonia. Imaging revealed two large anterior osteophytes at C1-C2. She underwent endoscopic trans-oral osteophytectomy with resolution of symptoms. Five other patients are also presented who underwent similar procedures.CONCLUSIONS: ACOs are a potential cause of dysphagia, and their diagnosis is best made with CT imaging and oropharyngeal swallow study. Although high ACOs at C1-C2 are a rare finding, here we show with an exemplary case and small case series that they can be effectively treated with trans-oral endoscopic osteophytectomy.

  View details for PubMedID 30193964

• Anterior Techniques in Managing Cervical Disc Disease. Cureus Kim, L. H., D'Souza, M., Ho, A. L., Pendharkar, A. V., Sussman, E. S., Rezaii, P., Desai, A. 2018; 10 (8): e3146

  Abstract

  Surgical treatment may be indicated for select patients with cervical disc disease, whether it is cervical disc herniation or spondylosis due to degenerative changes, acute cervical injury due to trauma, or other underlying cervical pathology.Currently, there are various surgical techniques, including anterior, posterior, or combined approaches, in addition to new interventions being utilized in practice. Ideally, the surgical approach should be selected in consideration of each patient's clinical presentation, imaging findings, and overall medical comorbidities on an individual basis. But the unique advantages and disadvantages of each surgical technique often complicate the therapy choice in managing cervical disc diseases. Although anterior cervical discectomy and fusion (ACDF) is the most widely accepted procedure performed for both single and multi-level cervical disc diseases, there are multiple modifications to this technique. Surgeons have access to different types of plates, screws, and cages and can adopt newer advances in the field such as stand-alone and minimally invasive techniques when indicated. In short, no consensus exists in terms of a single approach that is preferredfor all patients. This article aims to review the standard of care for management of cervical disc disease with a focus on the surgical techniques and, in particular, the anterior approach, exploring the various surgical options within this technique.

  View details for PubMedID 30410821

• Anterior Techniques in Managing Cervical Disc Disease CUREUS Kim, L. H., D'Souza, M., Ho, A. L., Pendharkar, A. V., Sussman, E. S., Rezaii, P., Desai, A. 2018; 10 (8)

  View details for DOI 10.7759/cureus.3146

  View details for Web of Science ID 000450944400065

• Outpatient spine surgery: defining the outcomes, value, and barriers to implementation. Neurosurgical focus Pendharkar, A. V., Shahin, M. N., Ho, A. L., Sussman, E. S., Purger, D. A., Veeravagu, A., Ratliff, J. K., Desai, A. M. 2018; 44 (5): E11

  Abstract

  Spine surgery is a key target for cost reduction within the United States health care system. One possible strategy involves the transition of inpatient surgeries to the ambulatory setting. Lumbar laminectomy with or without discectomy, lumbar fusion, anterior cervical discectomy and fusion, and cervical disc arthroplasty all represent promising candidates for outpatient surgeries in select populations. In this focused review, the authors clarify the different definitions used in studies describing outpatient spine surgery. They also discuss the body of evidence supporting each of these procedures and summarize the proposed cost savings. Finally, they examine several patient- and surgeon-specific considerations to highlight the barriers in translating outpatient spine surgery into actual practice.

  View details for PubMedID 29712520

• Outpatient spine surgery: defining the outcomes, value, and barriers to implementation NEUROSURGICAL FOCUS Pendharkar, A., Shahin, M., Ho, A., Sussman, E., Purger, D., Veeravagu, A., Ratliff, J., Desai, A. 2018; 44 (5)

  View details for DOI 10.3171/2018.2.FOCUS17790

  View details for Web of Science ID 000431292300011

• Propensity-matched comparison of outcomes and cost after macroscopic and microscopic lumbar discectomy using a national longitudinal database NEUROSURGICAL FOCUS Pendharkar, A., Rezaii, P., Ho, A., Sussman, E., Purger, D., Veeravagu, A., Ratliff, J., Desai, A. 2018; 44 (5)

  View details for DOI 10.3171/2018.1.FOCUS17791

  View details for Web of Science ID 000431292300012

• Propensity-matched comparison of outcomes and cost after macroscopic and microscopic lumbar discectomy using a national longitudinal database. Neurosurgical focus Pendharkar, A. V., Rezaii, P. G., Ho, A. L., Sussman, E. S., Purger, D. A., Veeravagu, A., Ratliff, J. K., Desai, A. M. 2018; 44 (5): E12

  Abstract

  OBJECTIVE There has been considerable debate about the utility of the operating microscope in lumbar discectomy and its effect on outcomes and cost. METHODS A commercially available longitudinal database was used to identify patients undergoing discectomy with or without use of a microscope between 2007 and 2015. Propensity matching was performed to normalize differences between demographics and comorbidities in the 2 cohorts. Outcomes, complications, and cost were subsequently analyzed using bivariate analysis. RESULTS A total of 42,025 patients were identified for the "macroscopic" group, while 11,172 patients were identified for the "microscopic" group. For the propensity-matched analysis, the 11,172 patients in the microscopic discectomy group were compared with a group of 22,340 matched patients who underwent macroscopic discectomy. There were no significant differences in postoperative complications between the groups other than a higher proportion of deep vein thrombosis (DVT) in the macroscopic discectomy cohort versus the microscopic discectomy group (0.4% vs 0.2%, matched OR 0.48 [95% CI 0.26-0.82], p = 0.0045). Length of stay was significantly longer in the macroscopic group compared to the microscopic group (mean 2.13 vs 1.83 days, p < 0.0001). Macroscopic discectomy patients had a higher rate of revision surgery when compared to microscopic discectomy patients (OR 0.92 [95% CI 0.84-1.00], p = 0.0366). Hospital charges were higher in the macroscopic discectomy group (mean $19,490 vs $14,921, p < 0.0001). CONCLUSIONS The present study suggests that the use of the operating microscope in lumbar discectomy is associated with decreased length of stay, lower DVT rate, lower reoperation rate, and decreased overall hospital costs.

  View details for PubMedID 29712527

• Outpatient vs Inpatient Anterior Cervical Discectomy and Fusion: A Population-Level Analysis of Outcomes and Cost NEUROSURGERY Purger, D. A., Pendharkar, A. V., Ho, A. L., Sussman, E. S., Yang, L., Desai, M., Veeravagu, A., Ratliff, J. K., Desai, A. 2018; 82 (4): 454–63

  View details for DOI 10.1093/neuros/nyx215

  View details for Web of Science ID 000439686300011

• Preoperative depression, lumbar fusion, and opioid use: an assessment of postoperative prescription, quality, and economic outcomes. Neurosurgical focus O'Connell, C. n., Azad, T. D., Mittal, V. n., Vail, D. n., Johnson, E. n., Desai, A. n., Sun, E. n., Ratliff, J. K., Veeravagu, A. n. 2018; 44 (1): E5

  Abstract

  OBJECTIVE Preoperative depression has been linked to a variety of adverse outcomes following lumbar fusion, including increased pain, disability, and 30-day readmission rates. The goal of the present study was to determine whether preoperative depression is associated with increased narcotic use following lumbar fusion. Moreover, the authors examined the association between preoperative depression and a variety of secondary quality indicator and economic outcomes, including complications, 30-day readmissions, revision surgeries, likelihood of discharge home, and 1- and 2-year costs. METHODS A retrospective analysis was conducted using a national longitudinal administrative database (MarketScan) containing diagnostic and reimbursement data on patients with a variety of private insurance providers and Medicare for the period from 2007 to 2014. Multivariable logistic and negative binomial regressions were performed to assess the relationship between preoperative depression and the primary postoperative opioid use outcomes while controlling for demographic, comorbidity, and preoperative prescription drug-use variables. Logistic and log-linear regressions were also used to evaluate the association between depression and the secondary outcomes of complications, 30-day readmissions, revisions, likelihood of discharge home, and 1- and 2-year costs. RESULTS The authors identified 60,597 patients who had undergone lumbar fusion and met the study inclusion criteria, 4985 of whom also had a preoperative diagnosis of depression and 21,905 of whom had a diagnosis of spondylolisthesis at the time of surgery. A preoperative depression diagnosis was associated with increased cumulative opioid use (β = 0.25, p < 0.001), an increased risk of chronic use (OR 1.28, 95% CI 1.17-1.40), and a decreased probability of opioid cessation (OR 0.96, 95% CI 0.95-0.98) following lumbar fusion. In terms of secondary outcomes, preoperative depression was also associated with a slightly increased risk of complications (OR 1.14, 95% CI 1.03-1.25), revision fusions (OR 1.15, 95% CI 1.05-1.26), and 30-day readmissions (OR 1.19, 95% CI 1.04-1.36), although it was not significantly associated with the probability of discharge to home (OR 0.92, 95% CI 0.84-1.01). Preoperative depression also resulted in increased costs at 1 (β = 0.06, p < 0.001) and 2 (β = 0.09, p < 0.001) years postoperatively. CONCLUSIONS Although these findings must be interpreted in the context of the limitations inherent to retrospective studies utilizing administrative data, they provide additional evidence for the link between a preoperative diagnosis of depression and adverse outcomes, particularly increased opioid use, following lumbar fusion.

  View details for DOI 10.3171/2017.10.FOCUS17563

  View details for PubMedID 29290135

• Efficacy and safety of corpus callosotomy after vagal nerve stimulation in patients with drug-resistant epilepsy JOURNAL OF NEUROSURGERY Hong, J., Desai, A., Thadani, V. M., Roberts, D. W. 2018; 128 (1): 277–86

  Abstract

  OBJECTIVE Vagal nerve stimulation (VNS) and corpus callosotomy (CC) have both been shown to be of benefit in the treatment of medically refractory epilepsy. Recent case series have reviewed the efficacy of VNS in patients who have undergone CC, with encouraging results. There are few data, however, on the use of CC following VNS therapy. METHODS The records of all patients at the authors' center who underwent CC following VNS between 1998 and 2015 were reviewed. Patient baseline characteristics, operative details, and postoperative outcomes were analyzed. RESULTS Ten patients met inclusion criteria. The median follow-up was 72 months, with a minimum follow-up of 12 months (range 12-109 months). The mean time between VNS and CC was 53.7 months. The most common reason for CC was progression of seizures after VNS. Seven patients had anterior CC, and 3 patients returned to the operating room for a completion of the procedure. All patients had a decrease in the rate of falls and drop seizures; 7 patients experienced elimination of drop seizures. Nine patients had an Engel Class III outcome, and 1 patient had a Class IV outcome. There were 3 immediate postoperative complications and 1 delayed complication. One patient developed pneumonia, 1 developed transient mutism, and 1 had persistent weakness in the nondominant foot. One patient presented with a wound infection. CONCLUSIONS The authors demonstrate that CC can help reduce seizures in patients with medically refractory epilepsy following VNS, particularly with respect to drop attacks.

  View details for PubMedID 28298036

• Impact of Inpatient Venous Thromboembolism Continues After Discharge: Retrospective Propensity Scored Analysis in a Longitudinal Database CLINICAL SPINE SURGERY Li, A. Y., Azad, T. D., Veeravagu, A., Bhatti, I., Li, A., Cole, T., Desai, A., Ratliff, J. K. 2017; 30 (10): E1392–E1398

  View details for DOI 10.1097/BSD.0000000000000437

  View details for Web of Science ID 000416241600010

• Spine Stereotactic Radiosurgery: Outcomes and Predictors of Local Recurrence Kumar, K. A., Fujimoto, D. K., White, E. C., Ho, C. K., Azoulay, M., Gibbs, I. C., Adler, J. R., Chang, S. D., Hancock, S. L., Desai, A., Ratliff, J., Soltys, S. G., Choi, C. H. ELSEVIER SCIENCE INC. 2017: E86

  View details for DOI 10.1016/j.ijrobp.2017.06.796

  View details for Web of Science ID 000411559100201

• Stereotactic Radiosurgery for Benign Neurogenic Spinal Tumors Chin, A. L., Fujimoto, D. K., Tse, V., Chang, S. D., Adler, J. R., Gibbs, I. C., Dodd, R. L., Li, G., Gephart, M. H., Desai, A., Ratliff, J., Sachdev, S., Soltys, S. G. ELSEVIER SCIENCE INC. 2017: S186

  View details for DOI 10.1016/j.ijrobp.2017.06.464

  View details for Web of Science ID 000411559107212

• Outpatient vs Inpatient Anterior Cervical Discectomy and Fusion: A Population-Level Analysis of Outcomes and Cost. Neurosurgery Purger, D. A., Pendharkar, A. V., Ho, A. L., Sussman, E. S., Yang, L., Desai, M., Veeravagu, A., Ratliff, J. K., Desai, A. 2017

  Abstract

  Outpatient anterior cervical discectomy and fusion (ACDF) is a promising candidate for US healthcare cost reduction as several studies have demonstrated that overall complications are relatively low and early discharge can preserve high patient satisfaction, low morbidity, and minimal readmission.To compare clinical outcomes and associated costs between inpatient and ambulatory setting ACDF.Demographics, comorbidities, emergency department (ED) visits, readmissions, reoperation rates, and 90-d charges were retrospectively analyzed for patients undergoing elective ACDF in California, Florida, and New York from 2009 to 2011 in State Inpatient and Ambulatory Databases.A total of 3135 ambulatory and 46 996 inpatient ACDFs were performed. Mean Charlson comorbidity index, length of stay, and mortality were 0.2, 0.4 d, and 0% in the ambulatory cohort and 0.4, 1.8 d, and 0.04% for inpatients ( P < .0001). Ambulatory patients were younger (48.0 vs 53.1) and more likely to be Caucasian. One hundred sixty-eight ambulatory patients (5.4%) presented to the ED within 30 d (mean 11.3 d), 51 (1.6%) were readmitted, and 5 (0.2%) underwent reoperation. Among inpatient surgeries, 2607 patients (5.5%) presented to the ED within 30 d (mean 9.7 d), 1778 (3.8%) were readmitted (mean 6.3 d), and 200 (0.4%) underwent reoperation. Higher Charlson comorbidity index increased rate of ED visits (ambulatory operating room [OR] 1.285, P < .05; inpatient OR 1.289, P < .0001) and readmission (ambulatory OR 1.746, P < .0001; inpatient OR 1.685, P < .0001). Overall charges were significantly lower for ambulatory ACDFs ($33 362.51 vs $74 667.04; P < .0001).ACDF can be performed in an ambulatory setting with comparable morbidity and readmission rates, and lower costs, to those performed in an inpatient setting.

  View details for DOI 10.1093/neuros/nyx215

  View details for PubMedID 28498922

• Predicting complication risk in spine surgery: a prospective analysis of a novel risk assessment tool. Journal of neurosurgery. Spine Veeravagu, A., Li, A., Swinney, C., Tian, L., Moraff, A., Azad, T. D., Cheng, I., Alamin, T., Hu, S. S., Anderson, R. L., Shuer, L., Desai, A., Park, J., Olshen, R. A., Ratliff, J. K. 2017: 1-11

  Abstract

  OBJECTIVE The ability to assess the risk of adverse events based on known patient factors and comorbidities would provide more effective preoperative risk stratification. Present risk assessment in spine surgery is limited. An adverse event prediction tool was developed to predict the risk of complications after spine surgery and tested on a prospective patient cohort. METHODS The spinal Risk Assessment Tool (RAT), a novel instrument for the assessment of risk for patients undergoing spine surgery that was developed based on an administrative claims database, was prospectively applied to 246 patients undergoing 257 spinal procedures over a 3-month period. Prospectively collected data were used to compare the RAT to the Charlson Comorbidity Index (CCI) and the American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) Surgical Risk Calculator. Study end point was occurrence and type of complication after spine surgery. RESULTS The authors identified 69 patients (73 procedures) who experienced a complication over the prospective study period. Cardiac complications were most common (10.2%). Receiver operating characteristic (ROC) curves were calculated to compare complication outcomes using the different assessment tools. Area under the curve (AUC) analysis showed comparable predictive accuracy between the RAT and the ACS NSQIP calculator (0.670 [95% CI 0.60-0.74] in RAT, 0.669 [95% CI 0.60-0.74] in NSQIP). The CCI was not accurate in predicting complication occurrence (0.55 [95% CI 0.48-0.62]). The RAT produced mean probabilities of 34.6% for patients who had a complication and 24% for patients who did not (p = 0.0003). The generated predicted values were stratified into low, medium, and high rates. For the RAT, the predicted complication rate was 10.1% in the low-risk group (observed rate 12.8%), 21.9% in the medium-risk group (observed 31.8%), and 49.7% in the high-risk group (observed 41.2%). The ACS NSQIP calculator consistently produced complication predictions that underestimated complication occurrence: 3.4% in the low-risk group (observed 12.6%), 5.9% in the medium-risk group (observed 34.5%), and 12.5% in the high-risk group (observed 38.8%). The RAT was more accurate than the ACS NSQIP calculator (p = 0.0018). CONCLUSIONS While the RAT and ACS NSQIP calculator were both able to identify patients more likely to experience complications following spine surgery, both have substantial room for improvement. Risk stratification is feasible in spine surgery procedures; currently used measures have low accuracy.

  View details for DOI 10.3171/2016.12.SPINE16969

  View details for PubMedID 28430052

• The effect of socioeconomic status on gross total resection, radiation therapy and overall survival in patients with gliomas. Journal of neuro-oncology Deb, S., Pendharkar, A. V., Schoen, M. K., Altekruse, S., Ratliff, J., Desai, A. 2017

  Abstract

  Socioeconomic status (SES) is associated with survival in many cancers but the effect of socioeconomic status on survival and access to care for patients with gliomas has not been well studied. This study included 50,170 patients from the Surveillance, Epidemiology, and End Results Program at the National Cancer Institute database diagnosed with gliomas of the brain from 2003 to 2012. Patient SES was divided into tertiles and quintiles. Treatment options included radiation, surgery (gross total resection (GTR)/other surgery), and radiation with surgery. Multivariable logistic regression and Cox proportional hazards model were used to analyze data with SAS v9.4. The results were adjusted for age at diagnosis, race, sex, tumor type, and tumor grade. Kaplan-Meier survival curves were constructed according to SES tertiles and quintiles. Patients from a higher SES tertile were significantly more likely to receive surgery, radiation, GTR, and radiation with surgery (OR 1.092, 1.116, 1.103, 1.150 respectively, all p < 0.0001). This correlation was also true when patients were divided into quintiles (OR 1.054, 1.072, 1.062, 1.089 respectively, all p < 0.0001). Furthermore, the lowest SES tertiles (HR 1.258, 1.146) and the lowest SES quintiles (HR 1.301, 1.273, 1.194, 1.119) were associated with significantly shorter survival times (all p for trend <0.0001). Surgery, radiation therapy, surgery with radiation therapy, and GTR were also found to be associated with improved overall survival in glioma patients (HR 0.553, 0.849, 0.666, 0.491 respectively, all p < 0.0001). The findings from this national study suggest an effect of SES on access to treatment, and survival in patients with gliomas.

  View details for DOI 10.1007/s11060-017-2391-2

  View details for PubMedID 28258423

• Cervical Osteochondroma Causing Myelopathy in Adults: Management Considerations and Literature Review WORLD NEUROSURGERY Veeravagu, A., Li, A., Shuer, L. M., Desai, A. M. 2017; 97

  Abstract

  Osteochondromas are the most frequent benign bone tumors but only rarely occur along the spinal column and even more rarely induce symptoms from spinal cord compression.We report 2 adult patients, both with a history of hereditary multiple exostoses, who presented with cervical myelopathy secondary to osteochondromas. The first patient is a 22-year-old man with numbness and weakness of his right upper limb and neck pain. Radiologic images showed a bony tumor arising from the C3 lamina with evidence of severe spinal cord compression. The second patient is a 20-year-old woman with weakness of her left upper and lower limbs and progressive numbness of the left hand, as well as neck and back pain. Radiologic images showed a bony tumor arising from the C4 lamina with evidence of significant spinal cord compression and cord signal abnormality. Both patients underwent surgical excision of the epidural mass and pathology confirmed a diagnosis of osteochondroma.We discuss the role of surgical intervention, management, and postoperative follow-up in adult patients with cervical osteochondromas. Recommended management includes radiographic imaging and surgical intervention, particularly when evidence of spinal cord impingement occurs. Consistent postoperative follow-up is necessary to ensure appropriate recovery of neurologic function. Surgical management of cervical osteochondromas typically results in excellent and stable clinical outcomes with rare recurrence.

  View details for DOI 10.1016/j.wneu.2016.10.061

  View details for Web of Science ID 000396449400122

• Impact of Inpatient Venous Thromboembolism Continues After Discharge: Retrospective Propensity Scored Analysis in a Longitudinal Database. Clinical spine surgery Li, A. Y., Azad, T. D., Veeravagu, A., Bhatti, I., Li, A., Cole, T., Desai, A., Ratliff, J. K. 2016: -?

  Abstract

  Propensity score matched retrospective study using a nationwide longitudinal database.To quantify the longitudinal economic impact of venous thromboembolism (VTE) complications in spinal fusion patients.VTE is a rare and serious complication that may occur after spine surgery. The long-term socioeconomic impact understanding of these events has been limited by small sample sizes and a lack of longitudinal follow-up. We provide a comparative economic outcomes analysis of these complications.We identified 204,308 patients undergoing spinal fusion procedures in a national billing claims database (MarketScan) between 2006 and 2010. Cohorts were balanced using 50:1 propensity score matching and outcome measures compared at 6, 12, and 18 months postoperation.A total of 1196 (0.6%) patients developed postoperative VTE, predominantly occurring following lumbar fusion (69.7%). Postoperative VTE patients demonstrated an increase in hospital length of stay (7.8 vs. 3.3 d, P<0.001) and a decreased likelihood of being discharged home (71% vs. 85%, P<0.001). A $26,306 increase in total hospital payments (P<0.001) was observed, with a disproportionate increase seen in hospital payments ($22,103, P<0.001), relative to physician payments ($1766, P=0.001).At 6, 12, and 18 months postfusion, increased rates of readmission and follow-up clinic visits were observed. Delayed readmissions were associated with decreased length of stay (3.6 vs. 4.6 d, P<0.001), but increased total payments, averaging at $21,270 per readmission. VTE patients generated greater cumulative outpatient service payments, costing $8075, $11,134, and $13,202 more at 6, 12, and 18 months (P<0.001).VTEs are associated with longer hospitalizations, a decreased likelihood of being discharged home, and overall increases of hospital resource utilization and cost in inpatient and outpatient settings. VTE patients generate greater charges in the outpatient setting and are more likely to become readmitted at 6, 12, and 18 months after surgery, demonstrating a significant socioeconomic impact long after occurrence.Level III-therapeutic.

  View details for PubMedID 27750270

• Surgical outcomes of cervical spondylotic myelopathy: an analysis of a national, administrative, longitudinal database. Neurosurgical focus Veeravagu, A., Connolly, I. D., Lamsam, L., Li, A., Swinney, C., Azad, T. D., Desai, A., Ratliff, J. K. 2016; 40 (6): E11-?

  Abstract

  OBJECTIVE The authors performed a population-based analysis of national trends, costs, and outcomes associated with cervical spondylotic myelopathy (CSM) in the United States. They assessed postoperative complications, resource utilization, and predictors of costs, in this surgically treated CSM population. METHODS MarketScan data (2006-2010) were used to retrospectively analyze the complications and costs of different spine surgeries for CSM. The authors determined outcomes following anterior cervical discectomy and fusion (ACDF), posterior fusion, combined anterior/posterior fusion, and laminoplasty procedures. RESULTS The authors identified 35,962 CSM patients, comprising 5154 elderly (age ≥ 65 years) patients (mean 72.2 years, 54.9% male) and 30,808 nonelderly patients (mean 51.1 years, 49.3% male). They found an overall complication rate of 15.6% after ACDF, 29.2% after posterior fusion, 41.1% after combined anterior and posterior fusion, and 22.4% after laminoplasty. Following ACDF and posterior fusion, a significantly higher risk of complication was seen in the elderly compared with the nonelderly (reference group). The fusion level and comorbidity-adjusted ORs with 95% CIs for these groups were 1.54 (1.40-1.68) and 1.25 (1.06-1.46), respectively. In contrast, the elderly population had lower 30-day readmission rates in all 4 surgical cohorts (ACDF, 2.6%; posterior fusion, 5.3%; anterior/posterior fusion, 3.4%; and laminoplasty, 3.6%). The fusion level and comorbidity-adjusted odds ratios for 30-day readmissions for ACDF, posterior fusion, combined anterior and posterior fusion, and laminoplasty were 0.54 (0.44-0.68), 0.32 (0.24-0.44), 0.17 (0.08-0.38), and 0.39 (0.18-0.85), respectively. CONCLUSIONS The authors' analysis of the MarketScan database suggests a higher complication rate in the surgical treatment of CSM than previous national estimates. They found that elderly age (≥ 65 years) significantly increased complication risk following ACDF and posterior fusion. Elderly patients were less likely to experience a readmission within 30 days of surgery. Postoperative complication occurrence, and 30-day readmission were significant drivers of total cost within 90 days of the index surgical procedure.

  View details for DOI 10.3171/2016.3.FOCUS1669

  View details for PubMedID 27246481

• Cervical Fusion for Absent Pedicle Syndrome Manifesting with Myelopathy WORLD NEUROSURGERY Goodwin, C. R., Desai, A., Khattab, M. H., Elder, B. D., Bydon, A., Wolinsky, J. 2016; 86

  Abstract

  Absent congenital pedicle syndrome is a posterior arch defect characterized by a host of congenital and mechanical abnormalities that result from disconnection of the anterior and posterior columns of the spinal canal. Absent congenital pedicle syndrome is a rare anomaly that is most commonly diagnosed either incidentally, after evaluation of minor trauma, or after complaints of chronic neck pain. To report a case of absent congenital pedicle syndrome who presented with myelopathy and lower extremity weakness and review the literature on the surgical management of this entity.A 32 year old female with a history of systemic lupus erythematous presented to the Neurosurgery Service with progressive weakness in her upper and lower extremities, clonus and hyperreflexia. MRI revealed congenital absence of the pedicles of C2, C3, C4, C5, and C6 with congenitally narrow canal at C4-5. The patient underwent a staged anterior and posterior cervical decompression and fusion. Postoperatively, she was placed in a halo and at one year follow up she was ambulatory with demonstrated improvement in her weakness and fusion of her cervical spine.Absent congenital pedicle syndrome is rare with the majority of reported cases treated conservatively. Surgical management is a treatment option reserved for patients with myelopathy or instability.

  View details for DOI 10.1016/j.wneu.2015.09.017

  View details for Web of Science ID 000369625300105

  View details for PubMedID 26386456

• Epidural spinal involvement of Erdheim-Chester disease causing myelopathy JOURNAL OF CLINICAL NEUROSCIENCE Hwang, B. Y., Liu, A., Kern, J., Goodwin, C. R., Wolinsky, J. P., Desai, A. 2015; 22 (9): 1532-1536

  Abstract

  We present a 25-year-old woman with Erdheim-Chester disease (ECD) presenting with progressive myelopathy from multiple compressive spinal epidural lesions who required cervicothoracic decompression and fusion, and summarize the literature on epidural spinal involvement of ECD. ECD is a rare non-Langerhans histiocytosis affecting multiple organ systems through infiltration and characteristically causing multifocal osteosclerosis. Central nervous system involvement, particularly of the spine, is rare.

  View details for DOI 10.1016/j.jocn.2015.04.004

  View details for Web of Science ID 000359167600037

  View details for PubMedID 26119978

• Surgical Management of Sacral Chordomas: Illustrative Cases and Current Management Paradigms CUREUS Pendharkar, A. V., Ho, A. L., Sussman, E. S., Desai, A. 2015; 7 (8)

  View details for DOI 10.7759/cureus.301

  View details for Web of Science ID 000453604900008

• Anterior Versus Posterior Approach for Multilevel Degenerative Cervical Disease A Retrospective Propensity Score-Matched Study of the MarketScan Database SPINE Cole, T., Veeravagu, A., Zhang, M., Azad, T. D., Desai, A., Ratliff, J. K. 2015; 40 (13): 1033-1038

  Abstract

  Retrospective 2:1 propensity score-matched analysis on a national longitudinal database between 2006 and 2010.To compare rates of adverse events, revisions procedure rates, and payment differences in anterior cervical fusion procedures compared with posterior laminectomy and fusion procedures with at least 3 levels of instrumentation.The comparative benefits of anterior versus posterior approach to multilevel degenerative cervical disease remain controversial. Recent systematic reviews have reached conflicting conclusions. We demonstrate the comparative economic and clinical outcomes of anterior and posterior approaches for multilevel cervical degenerative disk disease.We identified 13,662 patients in a national billing claims database who underwent anterior or posterior cervical fusion procedures with 3 or more levels of instrumentation. Cohorts were balanced using 2:1 propensity score matching and outcomes were compared using bivariate analysis.With the exception of dysphagia (6.4% in anterior and 1.4% in posterior), overall 30-day complication rates were lower in the anterior approach group. The rate of any complication excluding dysphagia with anterior approaches was 12.3%, significantly lower (P < 0.0001) than that of posterior approaches, 17.8%. Anterior approaches resulted in lower hospital ($18,346 vs. $23,638) and total payments ($28,963 vs. $33,526). Patients receiving an anterior surgical approach demonstrated significantly lower rate of 30-day readmission (5.1% vs. 9.9%, P < 0.0001), were less likely to require revision surgery (12.8% vs. 18.1%, P < 0.0001), and had a shorter length of stay by 1.5 nights (P < 0.0001).Anterior approaches in the surgical management of multilevel degenerative cervical disease provide clinical advantages over posterior approaches, including lower overall complication rates, revision procedure rates, and decreased length of stay. Anterior approach procedures are also associated with decreased overall payments. These findings must be interpreted in light of limitations inherent to retrospective longitudinal studies including absence of subjective and radiographical outcomes.3.

  View details for DOI 10.1097/BRS.0000000000000872

  View details for Web of Science ID 000357946000009

• SPORT: Does Incidental Durotomy Affect Longterm Outcomes in Cases of Spinal Stenosis? Neurosurgery Desai, A., Ball, P. A., Bekelis, K., Lurie, J., Mirza, S. K., Tosteson, T. D., Weinstein, J. N. 2015; 76: S57-63

  Abstract

  Incidental durotomy is a familiar encounter during surgery for lumbar spinal stenosis. The impact of durotomy on long-term outcomes remains a matter of debate.To determine the impact of durotomy on the long-term outcomes of patients in the Spine Patient Outcomes Research Trial (SPORT).The SPORT cohort participants with a confirmed diagnosis of spinal stenosis, without associated spondylolisthesis, undergoing standard, first-time, open decompressive laminectomy, with or without fusion, were followed up from baseline at 6 weeks, and 3, 6, and 12 months and yearly thereafter at 13 spine clinics in 11 US states. Patient data from this prospectively gathered database were reviewed. As of May 2009, the mean follow-up among all analyzed patients was 43.8 months.Four hundred nine patients underwent first-time open laminectomy with or without fusion. Thirty-seven of these patients (9%) had an incidental durotomy. No significant differences were observed with or without durotomy in age; sex; race; body mass index; the prevalence of smoking, diabetes mellitus, and hypertension; decompression level; number of levels decompressed; or whether an additional fusion was performed. The durotomy group had significantly increased operative duration, operative blood loss, and inpatient stay. There were, however, no differences in incidence of nerve root injury, mortality, additional surgeries, or primary outcomes (Short Form-36 Bodily Pain or Physical Function scores or Oswestry Disability Index) at yearly follow-ups to 4 years.Incidental durotomy during first-time lumbar laminectomy for spinal stenosis did not impact long-term outcomes in affected patients.SBI, Stenosis Bothersomeness Index; SF-36, Short Form-36; SPORT, Spine Patient Outcomes Research Trial.

  View details for DOI 10.1227/01.neu.0000462078.58454.f4

  View details for PubMedID 25692369

• Surgical Management of Sacral Chordomas: Illustrative Cases and Current Management Paradigms. Cure¯us Pendharkar, A. V., Ho, A. L., Sussman, E. S., Desai, A. 2015; 7 (8)

  Abstract

  Sacral chordomas represent more than 50% of all sacral tumors. These slow-growing, malignant lesions present insidiously and are often large and intimately involved with sacral neurovascular and pelvic structures. En bloc resection is the only well-established predictor of progression-free survival. Optimal surgical management requires a complex multi-disciplinary approach. Here, we describe two cases of sacral chordoma and review current management paradigms.

  View details for DOI 10.7759/cureus.301

  View details for PubMedID 26430575

• Utility of Routine Outpatient Cervical Spine Imaging Following Anterior Cervical Corpectomy and Fusion. Cure¯us Desai, A., Pendharkar, A. V., Swienckowski, J. G., Ball, P. A., Lollis, S., Simmons, N. E. 2015; 7 (11)

  Abstract

  Construct failure is an uncommon but well-recognized complication following anterior cervical corpectomy and fusion (ACCF). In order to screen for these complications, many centers routinely image patients at outpatient visits following surgery. There remains, however, little data on the utility of such imaging.The electronic medical record of all patients undergoing anterior cervical corpectomy and fusion at Dartmouth-Hitchcock Medical Center between 2004 and 2009 were reviewed. All patients had routine cervical spine radiographs performed perioperatively. Follow-up visits up to two years postoperatively were analyzed. Sixty-five patients (mean age 52.2) underwent surgery during the time period. Eighteen patients were female. Forty patients had surgery performed for spondylosis, 20 for trauma, three for tumor, and two for infection. Forty-three patients underwent one-level corpectomy, 20 underwent two-level corpectomy, and two underwent three-level corpectomy, using an allograft, autograft, or both. Sixty-two of the fusions were instrumented using a plate and 13 had posterior augmentation. Fifty-seven patients had follow-up with imaging at four to 12 weeks following surgery, 54 with plain radiographs, two with CT scans, and one with an MRI scan. Unexpected findings were noted in six cases. One of those patients, found to have asymptomatic recurrent kyphosis following a two-level corpectomy, had repeat surgery because of those findings. Only one further patient was found to have abnormal imaging up to two years, and this patient required no further intervention.Routine imaging after ACCF can demonstrate asymptomatic occurrences of clinically significant instrument failure. In 43 consecutive single-level ACCF however, routine imaging did not change management, even when an abnormality was discovered. This may suggest a limited role for routine imaging after ACCF in longer constructs involving multiple levels.

  View details for DOI 10.7759/cureus.387

  View details for PubMedID 26719830

  View details for PubMedCentralID PMC4689583

• Utility of Provocative Discography WORLD NEUROSURGERY Gokaslan, Z. L., Desai, A. 2014; 82 (5): 638-639

  View details for DOI 10.1016/j.wneu.2014.02.013

  View details for Web of Science ID 000347252300058

  View details for PubMedID 24534063

• Outpatient follow-up of nonoperative cerebral contusion and traumatic subarachnoid hemorrhage: does repeat head CT alter clinical decision-making? JOURNAL OF NEUROSURGERY Rubino, S., Zaman, R. A., Sturge, C. R., Fried, J. G., Desai, A., Simmons, N. E., Lollis, S. S. 2014; 121 (4): 944-949

  Abstract

  Many neurosurgeons obtain repeat head CT at the first clinic follow-up visit for nonoperative cerebral contusion and traumatic subarachnoid hemorrhage (tSAH). The authors undertook a single-center, retrospective study to determine whether outpatient CT altered clinical decision-making.The authors evaluated 173 consecutive adult patients admitted to their institution from April 2006 to August 2012 with an admission diagnosis of cerebral contusion or tSAH and at least 1 clinic follow-up visit with CT. Patients with epidural, subdural, aneurysmal subarachnoid, or intraventricular hemorrhage, and those who underwent craniotomy, were excluded. Patient charts were reviewed for new CT findings, new patient symptoms, and changes in treatment plan. Patients were stratified by neurological symptoms into 3 groups: 1) asymptomatic; 2) mild, nonspecific symptoms; and 3) significant symptoms. Mild, nonspecific symptoms included minor headaches, vertigo, fatigue, and mild difficulties with concentration, short-term memory, or sleep; significant symptoms included moderate to severe headaches, nausea, vomiting, focal neurological complaints, impaired consciousness, or new cognitive impairment evident on routine clinical examination.One hundred seventy-three patients met inclusion criteria, with initial clinic follow-up obtained within approximately 6 weeks. Of the 173 patients, 104 (60.1%) were asymptomatic, 68 patients (39.3%) had mild, nonspecific neurological symptoms, and 1 patient (1.0%) had significant neurological symptoms. Of the asymptomatic patients, 3 patients (2.9%) had new CT findings and 1 of these patients (1.0%) underwent a change in treatment plan because of these findings. This change involved an additional clinic appointment and CT to monitor a 12-mm chronic subdural hematoma that ultimately resolved without treatment. Of the patients with mild, nonspecific neurological symptoms, 6 patients (8.8%) had new CT findings and 3 of these patients (4.4%) underwent a change in treatment plan because of these findings; none of these patients required surgical intervention. The single patient with significant neurological symptoms did not have any new CT findings.Repeat outpatient CT of asymptomatic patients after nonoperative cerebral contusion and tSAH is very unlikely to demonstrate significant new pathology. Given the cost and radiation exposure associated with CT, imaging should be reserved for patients with significant symptoms or focal findings on neurological examination.

  View details for DOI 10.3171/2014.6.JNS132204

  View details for Web of Science ID 000342973300028

  View details for PubMedID 25061865

• Incidence of Sacral Fractures and In-Hospital Postoperative Complications in the United States An Analysis of 2002-2011 Data SPINE Bydon, M., De la Garza-Ramos, R., Macki, M., Desai, A., Gokaslan, A. K., Bydon, A. 2014; 39 (18): E1103-E1109

  Abstract

  Retrospective study of an administrative database.To estimate the incidence of sacral fractures in the United States and report short-term outcomes after their surgical management.The incidence of sacral fractures in the United States is currently unknown, and these lesions have been associated with significant morbidity after their surgical management.This study used the Nationwide Inpatient Sample database for the years 2002-2011. All patients with a primary discharge diagnosis of a sacral fracture with and without a neurological injury were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes. Patients with a diagnosis of osteoporosis or pathological fracture were excluded. A stepwise multivariate logistic regression analysis was performed to identify factors associated with an in-hospital complication.During the study period, 10,177 patients with a nonosteoporotic sacral fracture were identified, of whom 1002 patients underwent surgery. Between 2002 and 2011, the estimated incidence of sacral fractures increased from 0.67 per 100,000 persons to 2.09 (P < 0.001). Similarly, the rate of surgical treatment for sacral fractures increased from 0.05 per 100,000 persons in 2002 to 0.24 per 100,000 in 2011 (P < 0.001). Complications occurred in 25.95% of patients and remained steady over time (P = 0.992). Average length of stay significantly decreased from 11.93 days to 9.66 days in the 10-year period (P = 0.023). The independent factors associated with an in-hospital complication were congestive heart failure (odds ratio, 3.65; 95% confidence interval, 1.18-11.26), coagulopathy (odds ratio, 3.58; 95% confidence interval, 1.88-6.81), and electrolyte abnormalities (odds ratio, 3.28; 95% confidence interval, 2.14-5.02).During the examined 10-year period, both the incidence of nonosteoporotic sacral fractures and the surgical treatment of these lesions increased in the United States. Between 2002 and 2011, although patient comorbidity increased, in-hospital complication rates remained stable and length of stay significantly decreased over time.4.

  View details for DOI 10.1097/BRS.0000000000000448

  View details for Web of Science ID 000341018000008

  View details for PubMedID 24875962

• A predictive model of complications after spine surgery: the National Surgical Quality Improvement Program (NSQIP) 2005-2010 SPINE JOURNAL Bekelis, K., Desai, A., Bakhoum, S. F., Missios, S. 2014; 14 (7): 1247-1255

  Abstract

  There is increasing scrutiny by several regulatory bodies regarding the complications of spine surgery. Precise delineation of the risks contributing to those complications remains a topic of debate.We attempted to create a predictive model of complications in patients undergoing spine surgery.Retrospective cohort study.A total of 13,660 patients registered in the American College of Surgeons National Quality Improvement Project (NSQIP) database.Thirty-day postoperative risks of stroke, myocardial infarction, death, infection, urinary tract infection (UTI), deep vein thrombosis (DVT), pulmonary embolism (PE), and return to the operating room.We performed a retrospective cohort study involving patients who underwent spine surgery between 2005 and 2010 and were registered in NSQIP. A model for outcome prediction based on individual patient characteristics was developed.Of the 13,660 patients, 2,719 underwent anterior approaches (19.9%), 565 corpectomies (4.1%), and 1,757 fusions (12.9%). The respective 30-day postoperative risks were 0.05% for stroke, 0.2% for MI, 0.25% for death, 0.3% for infection, 1.37% for UTI, 0.6% for DVT, 0.29% for PE, and 3.15% for return to the operating room. Multivariate analysis demonstrated that increasing age, more extensive operations (fusion, corpectomy), medical deconditioning (weight loss, dialysis, peripheral vascular disease, coronary artery disease, chronic obstructive pulmonary disease, diabetes), increasing body mass index, non-independent mobilization (preoperative neurologic deficit), and bleeding disorders were independently associated with a more than 3 days' length of stay. A validated model for outcome prediction based on individual patient characteristics was developed. The accuracy of the model was estimated by the area under the receiver operating characteristic curve, which was 0.95, 0.82, 0.87, 0.75, 0.74, 0.78, 0.76, 0.74, and 0.65 for postoperative risk of stroke, myocardial infarction, death, infection, DVT, PE, UTI, length of stay of 3 days or longer, and return to the operating room, respectively.Our model can provide individualized estimates of the risks of postoperative complications based on preoperative conditions, and can potentially be used as an adjunct in decision-making for spine surgery.

  View details for DOI 10.1016/j.spinee.2013.08.009

  View details for Web of Science ID 000338467000026

  View details for PubMedID 24211097

• Predicting inpatient complications from cerebral aneurysm clipping: the Nationwide Inpatient Sample 2005-2009 JOURNAL OF NEUROSURGERY Bekelis, K., Missios, S., MacKenzie, T. A., Desai, A., Fischer, A., Labropoulos, N., Roberts, D. W. 2014; 120 (3): 591-598

  Abstract

  Precise delineation of individualized risks of morbidity and mortality is crucial in decision making in cerebrovascular neurosurgery. The authors attempted to create a predictive model of complications in patients undergoing cerebral aneurysm clipping (CAC).The authors performed a retrospective cohort study of patients who had undergone CAC in the period from 2005 to 2009 and were registered in the Nationwide Inpatient Sample (NIS) database. A model for outcome prediction based on preoperative individual patient characteristics was developed.Of the 7651 patients in the NIS who underwent CAC, 3682 (48.1%) had presented with unruptured aneurysms and 3969 (51.9%) with subarachnoid hemorrhage. The respective inpatient postoperative risks for death, unfavorable discharge, stroke, treated hydrocephalus, cardiac complications, deep vein thrombosis, pulmonary embolism, and acute renal failure were 0.7%, 15.3%, 5.3%, 1.5%, 1.3%, 0.6%, 2.0%, and 0.1% for those with unruptured aneurysms and 11.5%, 52.8%, 5.5%, 39.2%, 1.7%, 2.8%, 2.7%, and 0.8% for those with ruptured aneurysms. Multivariate analysis identified risk factors independently associated with the above outcomes. A validated model for outcome prediction based on individual patient characteristics was developed. The accuracy of the model was estimated using the area under the receiver operating characteristic curve, and it was found to have good discrimination.The featured model can provide individualized estimates of the risks of postoperative complications based on preoperative conditions and can potentially be used as an adjunct in decision making in cerebrovascular neurosurgery.

  View details for DOI 10.3171/2013.8.JNS13228

  View details for Web of Science ID 000332048800002

  View details for PubMedID 24032701

• Outcome prediction in intracranial tumor surgery: the National Surgical Quality Improvement Program 2005-2010 JOURNAL OF NEURO-ONCOLOGY Bekelis, K., Bakhoum, S. F., Desai, A., MacKenzie, T. A., Roberts, D. W. 2013; 113 (1): 57-64

  Abstract

  Accurate knowledge of individualized risks is crucial for decision-making in the surgical management of patients with brain tumors. Precise delineation of those risks remains a topic of debate. We attempted to create a predictive model of outcomes in patients undergoing craniotomies for tumor resection (CTR). We performed a retrospective cohort study involving patients who underwent CTR from 2005 to 2010 and were registered in the American College of Surgeons National Quality Improvement Project database. A model for outcome prediction based on individual patient characteristics was developed. Of the 1,834 patients, 457 had meningiomas (24.9 %) and 1377 had non-meningioma tumors (75.1 %). The respective 30-day postoperative risks were 2.1 % for stroke, 1.3 % for MI, 2.7 % for death, 2.4 % for deep surgical site infection, and 6.6 % for return to the OR. Multivariate analysis demonstrated that pre-operative tumor-related neurologic deficit, stroke, altered mental status, and weight loss, were independently associated with most outcomes, including post-operative MI, death, and deep surgical site infection. An additive effect of the variables on the risk of all outcomes was observed. A validated model for outcome prediction based on individual patient characteristics was developed. The accuracy of the model was estimated by the area under the receiver operating characteristic curve, which was 0.687, 0.929, 0.749, 0.746, and 0.679 for postoperative risk of stroke, MI, death, infection, and return to the OR, respectively. Our model can provide individualized estimates of the risks of post-operative complications based on pre-operative conditions, and can potentially be utilized as an adjunct in the decision-making for surgical intervention in brain tumor patients.

  View details for DOI 10.1007/s11060-013-1089-3

  View details for Web of Science ID 000318300700007

  View details for PubMedID 23436132

• Variation in Outcomes Across Centers After Surgery for Lumbar Stenosis and Degenerative Spondylolisthesis in the Spine Patient Outcomes Research Trial SPINE Desai, A., Bekelis, K., Ball, P. A., Lurie, J., Mirza, S. K., Tosteson, T. D., Zhao, W., Weinstein, J. N. 2013; 38 (8): 678-691

  Abstract

  Retrospective review of a prospectively collected database.To examine whether short- and long-term outcomes after surgery for lumbar stenosis (SPS) and degenerative spondylolisthesis (DS) vary across centers.Surgery has been shown to be of benefit for both SPS and DS. For both conditions, surgery often consists of laminectomy with or without fusion. Potential differences in outcomes of these overlapping procedures across various surgical centers have not yet been investigated.Spine Patient Outcomes Research Trial cohort participants with a confirmed diagnosis of SPS or DS undergoing surgery were followed from baseline at 6 weeks, 3, 6, and 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Baseline characteristics and short- and long-term outcomes were analyzed.A total of 793 patients underwent surgery. Significant differences were found between centers with regard to patient race, body mass index, treatment preference, neurological deficit, stenosis location, severity, and number of stenotic levels. Significant differences were also found in operative duration and blood loss, the incidence of durotomy, the length of hospital stay, and wound infection. When baseline differences were adjusted for, significant differences were still seen between centers in changes in patient functional outcome (Short Form-36 bodily pain and physical function, and Oswestry Disability Index) at 1 year after surgery. In addition, the cumulative adjusted change in the Oswestry Disability Index Score at 4 years significantly differed among centers, with Short Form-36 scores trending toward significance.There is a broad and statistically significant variation in short- and long-term outcomes after surgery for SPS and DS across various academic centers, when statistically significant baseline differences are adjusted for. The findings suggest that the choice of center affects outcome after these procedures, although further studies are required to investigate which center characteristics are most important.

  View details for DOI 10.1097/BRS.0b013e318278e571

  View details for Web of Science ID 000317565400017

  View details for PubMedID 23080425

• A Risk Factor-based Predictive Model of Outcomes in Carotid Endarterectomy The National Surgical Quality Improvement Program 2005-2010 STROKE Bekelis, K., Bakhoum, S. F., Desai, A., MacKenzie, T. A., Goodney, P., Labropoulos, N. 2013; 44 (4): 1085-?

  Abstract

  Accurate knowledge of individualized risks and benefits is crucial to the surgical management of patients undergoing carotid endarterectomy (CEA). Although large randomized trials have determined specific cutoffs for the degree of stenosis, precise delineation of patient-level risks remains a topic of debate, especially in real world practice. We attempted to create a risk factor-based predictive model of outcomes in CEA.We performed a retrospective cohort study involving patients who underwent CEAs from 2005 to 2010 and were registered in the American College of Surgeons National Quality Improvement Project database.Of the 35 698 patients, 20 015 were asymptomatic (56.1%) and 15 683 were symptomatic (43.9%). These patients demonstrated a 1.64% risk of stroke, 0.69% risk of myocardial infarction, and 0.75% risk of death within 30 days after CEA. Multivariate analysis demonstrated that increasing age, male sex, history of chronic obstructive pulmonary disease, myocardial infarction, angina, congestive heart failure, peripheral vascular disease, previous stroke or transient ischemic attack, and dialysis were independent risk factors associated with an increased risk of the combined outcome of postoperative stroke, myocardial infarction, or death. A validated model for outcome prediction based on individual patient characteristics was developed. There was a steep effect of age on the risk of myocardial infarction and death.This national study confirms that that risks of CEA vary dramatically based on patient-level characteristics. Because of limited discrimination, it cannot be used for individual patient risk assessment. However, it can be used as a baseline for improvement and development of more accurate predictive models based on other databases or prospective studies.

  View details for DOI 10.1161/STROKEAHA.111.674358

  View details for Web of Science ID 000316673900036

  View details for PubMedID 23412374

• Indications for treatment of recurrent carotid stenosis BRITISH JOURNAL OF SURGERY Bekelis, K., Moses, Z., Missios, S., Desai, A., Labropoulos, N. 2013; 100 (4): 440-447

  Abstract

  There is significant variation in the indications for intervention in patients with recurrent carotid artery stenosis. The aim of the present study was to describe these indications in a contemporary cohort of patients.This was a systematic review of all peer-reviewed studies reporting on the indications for carotid intervention in patients with recurrent stenosis after carotid endarterectomy (CEA) or carotid artery stenting (CAS) that were published between 1990 and 2012.There were 50 studies reporting on a total of 3524 patients undergoing a carotid procedure; of these, 3478 underwent CEA as the initial intervention. Reintervention was by CEA in 2403 patients and by CAS in 1121. Only 54·7 per cent of the patients were treated for any symptoms and, importantly, just 444 (23·1 per cent of 1926 symptomatic patients) underwent intervention for documented ipsilateral symptoms. None of the studies reported whether the patients were evaluated for other sources of emboli. The remaining 45·3 per cent of patients had asymptomatic restenosis and in the majority of the studies were treated when the degree of stenosis exceeded 80 per cent. The time to repeat intervention was significantly longer in patients with recurrent atherosclerosis, in asymptomatic patients and in patients undergoing CEA.The reported criteria for retreatment of carotid stenosis were not rigorous and there is still significant ambiguity surrounding the indications for intervention.

  View details for DOI 10.1002/bjs.9027

  View details for Web of Science ID 000314657200003

  View details for PubMedID 23288608

• Association of a higher density of specialist neuroscience providers with fewer deaths from stroke in the United States population JOURNAL OF NEUROSURGERY Desai, A., Bekelis, K., Zhao, W., Ball, P. A., Erkmen, K. 2013; 118 (2): 431-436

  Abstract

  Stroke is a leading cause of death and disability. Given that neurologists and neurosurgeons have special expertise in this area, the authors hypothesized that the density of neuroscience providers is associated with reduced mortality rates from stroke across US counties.This is a retrospective review of the Area Resource File 2009-2010, a national county-level health information database maintained by the US Department of Health and Human Services. The primary outcome variable was the 3-year (2004-2006) average in cerebrovascular disease deaths per million population for each county. The primary independent variable was the combined density of neurosurgeons and neurologists per million population in the year 2006. Multiple regression analysis was performed, adjusting for density of general practitioners (GPs), urbanicity of the county, and socioeconomic status of the residents of the county.In the 3141 counties analyzed, the median number of annual stroke deaths was 586 (interquartile range [IQR] 449-754), the median number of neuroscience providers was 0 (IQR 0-26), and the median number of GPs was 274 (IQR 175-410) per million population. On multivariate adjusted analysis, each increase of 1 neuroscience provider was associated with 0.38 fewer deaths from stroke per year (p < 0.001) per million population. Rural location (p < 0.001) and increased density of GPs (p < 0.001) were associated with increases in stroke-related mortality.Higher density of specialist neuroscience providers is associated with fewer deaths from stroke. This suggests that the availability of specialists is an important factor in survival after stroke, and underlines the importance of promoting specialist education and practice throughout the country.

  View details for DOI 10.3171/2012.10.JNS12518

  View details for Web of Science ID 000313937900034

  View details for PubMedID 23198833

• Occipitotemporal hippocampal depth electrodes in intracranial epilepsy monitoring: safety and utility JOURNAL OF NEUROSURGERY Bekelis, K., Desai, A., Kotlyar, A., Thadani, V., Jobst, B. C., Bujarski, K., Darcey, T. M., Roberts, D. W. 2013; 118 (2): 345-352

  Abstract

  Intracranial monitoring for epilepsy has been proven to enhance diagnostic accuracy and provide localizing information for surgical treatment of intractable seizures. The authors investigated the usefulness of hippocampal depth electrodes in the era of more advanced imaging techniques.Between 1988 and 2010, 100 patients underwent occipitotemporal hippocampal depth electrode (OHDE) implantation as part of invasive seizure monitoring, and their charts were retrospectively reviewed. The authors' technique involved the stereotactically guided (using the Leksell model G frame) implantation of a 12-contact depth electrode directed along the long axis of the hippocampus, through an occipital twist drill hole.Of the 100 patients (mean age 35.0 years [range 13-58 years], 51% male) who underwent intracranial investigation, 84 underwent resection of the seizure focus. Magnetic resonance imaging revealed mesial temporal sclerosis (MTS) in 27% of patients, showed abnormal findings without MTS in 55% of patients, and showed normal findings in 18% of patients. One patient developed a small asymptomatic occipital hemorrhage around the electrode tract. The use of OHDEs enabled epilepsy resection in 45.7% of patients who eventually underwent standard or selective temporal lobe resection. The hippocampal formation was spared during surgery because data obtained from the depth electrodes showed no or only secondary involvement in 14% of patients with preoperative temporal localization. The use of OHDEs prevented resections in 12% of patients with radiographic evidence of MTS. Eighty-three percent of patients who underwent resection had Engel Class I (68%) or II (15%) outcome at 2 years of follow-up.The use of OHDEs for intracranial epilepsy monitoring has a favorable risk profile, and in the authors' experience it proved to be a valuable component of intracranial investigation. The use of OHDEs can provide the sole evidence for resection of some epileptogenic foci and can also result in hippocampal sparing or prevent likely unsuccessful resection in other patients.

  View details for DOI 10.3171/2012.9.JNS112221

  View details for Web of Science ID 000313937900018

  View details for PubMedID 23082879

• Interictal PET and ictal subtraction SPECT: Sensitivity in the detection of seizure foci in patients with medically intractable epilepsy EPILEPSIA Desai, A., Bekelis, K., Thadani, V. M., Roberts, D. W., Jobst, B. C., Duhaime, A., Gilbert, K., Darcey, T. M., Studholme, C., Siegel, A. 2013; 54 (2): 341-350

  Abstract

  Interictal positron emission tomography (PET) and ictal subtraction single photon emission computed tomography (SPECT) of the brain have been shown to be valuable tests in the presurgical evaluation of epilepsy. To determine the relative utility of these methods in the localization of seizure foci, we compared interictal PET and ictal subtraction SPECT to subdural and depth electrode recordings in patients with medically intractable epilepsy.Between 2003 and 2009, clinical information on all patients at our institution undergoing intracranial electroencephalography (EEG) monitoring was charted in a prospectively recorded database. Patients who underwent preoperative interictal PET and ictal subtraction SPECT were selected from this database. Patient characteristics and the findings on preoperative interictal PET and ictal subtraction SPECT were analyzed. Sensitivity of detection of seizure foci for each modality, as compared to intracranial EEG monitoring, was calculated.Fifty-three patients underwent intracranial EEG monitoring with preoperative interictal PET and ictal subtraction SPECT scans. The average patient age was 32.7 years (median 32 years, range 1-60 years). Twenty-seven patients had findings of reduced metabolism on interictal PET scan, whereas all 53 patients studied demonstrated a region of relative hyperperfusion on ictal subtraction SPECT suggestive of an epileptogenic zone. Intracranial EEG monitoring identified a single seizure focus in 45 patients, with 39 eventually undergoing resective surgery. Of the 45 patients in whom a seizure focus was localized, PET scan identified the same region in 25 cases (56% sensitivity) and SPECT in 39 cases (87% sensitivity). Intracranial EEG was concordant with at least one study in 41 cases (91%) and both studies in 23 cases (51%). In 16 (80%) of 20 cases where PET did not correlate with intracranial EEG, the SPECT study was concordant. Conversely, PET and intracranial EEG were concordant in two (33%) of the six cases where the SPECT did not demonstrate the seizure focus outlined by intracranial EEG. Thirty-three patients had surgical resection and >2 years of follow-up, and 21 of these (64%) had Engel class 1 outcome. No significant effect of imaging concordance on seizure outcome was seen.Interictal PET and ictal subtraction SPECT studies can provide important information in the preoperative evaluation of medically intractable epilepsy. Of the two studies, ictal subtraction SPECT appears to be the more sensitive. When both studies are used together, however, they can provide complementary information.

  View details for DOI 10.1111/j.1528-1167.2012.03686.x

  View details for Web of Science ID 000314750200018

  View details for PubMedID 23030361

• Subdural interhemispheric grid electrodes for intracranial epilepsy monitoring: feasibility, safety, and utility Clinical article JOURNAL OF NEUROSURGERY Bekelis, K., Radwan, T. A., Desai, A., Moses, Z. B., Thadani, V. M., Jobst, B. C., Bujarski, K. A., Darcey, T. M., Roberts, D. W. 2012; 117 (6): 1182-1188

  Abstract

  Intracranial monitoring for epilepsy has been proven to enhance diagnostic accuracy and provide localizing information for surgical treatment of intractable seizures. The authors investigated their experience with interhemispheric grid electrodes (IHGEs) to assess the hypothesis that they are feasible, safe, and useful.Between 1992 and 2010, 50 patients underwent IHGE implantation (curvilinear double-sided 2 × 8 or 3 × 8 grids) as part of arrays for invasive seizure monitoring, and their charts were retrospectively reviewed.Of the 50 patients who underwent intracranial investigation with IHGEs, 38 eventually underwent resection of the seizure focus. These 38 patients had a mean age of 30.7 years (range 11-58 years), and 63% were males. Complications as a result of IHGE implantation consisted of transient leg weakness in 1 patient. Of all the patients who underwent resective surgery, 21 (55.3%) had medial frontal resections, 9 of whom (43%) had normal MRI results. Localization in all of these cases was possible only because of data from IHGEs, and the extent of resection was tailored based on these data. Of the 17 patients (44.7%) who underwent other cortical resections, IHGEs were helpful in excluding medial seizure onset. Twelve patients did not undergo resection because of nonlocalizable or multifocal disease; in 2 patients localization to the motor cortex precluded resection. Seventy-one percent of patients who underwent resection had Engel Class I outcome at the 2-year follow-up.The use of IHGEs in intracranial epilepsy monitoring has a favorable risk profile and in the authors' experience proved to be a valuable component of intracranial investigation, providing the sole evidence for resection of some epileptogenic foci.

  View details for DOI 10.3171/2012.8.JNS12258

  View details for Web of Science ID 000311463900028

  View details for PubMedID 23061384

• Computed tomography angiography: improving diagnostic yield and cost effectiveness in the initial evaluation of spontaneous nonsubarachnoid intracerebral hemorrhage JOURNAL OF NEUROSURGERY Bekelis, K., Desai, A., Zhao, W., Gibson, D., Gologorsky, D., Eskey, C., Erkmen, K. 2012; 117 (4): 761-766

  Abstract

  Computed tomography angiography (CTA) is increasingly used as a screening tool in the investigation of spontaneous intracerebral hemorrhage (ICH). However, CTA carries additional costs and risks, necessitating its judicious use. The authors hypothesized that subsets of patients with nontraumatic, nonsubarachnoid ICH are unlikely to benefit from CTA as part of the diagnostic workup and that particular patient risk factors may be used to increase the yield of CTA in the detection of vascular sources.The authors performed a retrospective analysis of 1376 patients admitted to Dartmouth-Hitchcock Medical Center with ICH over an 8-year period. Patients with subarachnoid hemorrhage, hemorrhagic conversion of ischemic infarcts, trauma, and known prior malignancy were excluded from the analysis, resulting in 257 patients for final analysis. Records were reviewed for medical risk factors, hemorrhage location, and correlation of CTA findings with final diagnosis. Multiple logistic regression analysis was used to investigate the combined effects of baseline variables of interest. Model selection was conducted using the stepwise method with p = 0.10 as the significance level for variable entry and p = 0.05 the significance level for variable retention.Computed tomography angiography studies detected vascular pathology in 34 patients (13.2%). Patient characteristics that were associated with a significantly higher likelihood of identifying a structural vascular lesion as the source of hemorrhage included patient age younger than 65 years (OR = 16.36, p = 0.0039), female sex (OR = 14.9, p = 0.0126), nonsmokers (OR = 103.8, p = 0.0008), patients with intraventricular hemorrhage (OR = 9.42, p = 0.0379), and patients without hypertension (OR = 515.78, p < 0.0001). Patients who were older than 65 years of age, with a history of hypertension, and hemorrhage located in the cerebellum or basal ganglia were never found to have an identified structural source of hemorrhage on CTA.Patient characteristics and risk factors are important considerations when ordering diagnostic tests in the workup of nonsubarachnoid, nontraumatic spontaneous ICH. Although CTA is an accurate diagnostic examination, it can usually be omitted in the workup of patients with the described characteristics. The use of this algorithm has the potential to increase the yield, and thus the safety and cost effectiveness, of this diagnostic tool.

  View details for DOI 10.3171/2012.7.JNS12281

  View details for Web of Science ID 000309485600030

  View details for PubMedID 22880718

• Spine Patient Outcomes Research Trial: Do Outcomes Vary Across Centers for Surgery for Lumbar Disc Herniation? NEUROSURGERY Desai, A., Bekelis, K., Ball, P. A., Lurie, J., Mirza, S. K., Tosteson, T. D., Zhao, W., Weinstein, J. N. 2012; 71 (4): 833-842

  Abstract

  Lumbar discectomy is the most commonly performed spine procedure. Academic spine centers with potentially differing caseloads and experience may have different outcomes.To determine whether the choice of center in which surgery is performed affects lumbar discectomy outcomes.Spine Patient Outcomes Research Trial participants with a confirmed diagnosis of intervertebral disc herniation undergoing standard first-time open discectomy were followed from baseline at 6 weeks, and 3, 6, and 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Patient data from this prospective study were reviewed. Enrollment began in March 2000 and ended in November 2004.Seven hundred ninety-two patients underwent first-time lumbar discectomy. Significant differences were found among centers in patient age and race, baseline levels of disability, and treatment preferences. There were no significant differences among the centers in other patient characteristics (eg, sex, body mass index, the prevalence of smoking, diabetes, or hypertension), or disease characteristics (herniation level or type). Some short-term outcomes varied significantly among centers, including operative duration and blood loss, the incidence of durotomy, the length of hospital stay, and reoperation rate. However, there were no differences among the centers in incidence of nerve root injury, postoperative mortality, Short Form 36 scores of body pain or physical function, or Oswestry Disability Index at 4 years.Although mean blood loss, risk of durotomy, length of stay, and rate of reoperation vary among academic spine centers performing lumbar discectomy, there appears to be no difference in long-term functional outcomes.

  View details for DOI 10.1227/NEU.0b013e31826772cb

  View details for Web of Science ID 000309117200034

  View details for PubMedID 22791040

• Increased population density of neurosurgeons associated with decreased risk of death from motor vehicle accidents in the United States. Journal of neurosurgery Desai, A., Bekelis, K., Zhao, W., Ball, P. A. 2012; 117 (3): 599-603

  Abstract

  Motor vehicle accidents (MVAs) are a leading cause of death and disability in young people. Given that a major cause of death from MVAs is traumatic brain injury, and neurosurgeons hold special expertise in this area relative to other members of a trauma team, the authors hypothesized that neurosurgeon population density would be related to reduced mortality from MVAs across US counties.The Area Resource File (2009-2010), a national health resource information database, was retrospectively analyzed. The primary outcome variable was the 3-year (2004-2006) average in MVA deaths per million population for each county. The primary independent variable was the density of neurosurgeons per million population in the year 2006. Multiple regression analysis was performed, adjusting for population density of general practitioners, urbanicity of the county, and socioeconomic status of the county.The median number of annual MVA deaths per million population, in the 3141 counties analyzed, was 226 (interquartile range [IQR] 151-323). The median number of neurosurgeons per million population was 0 (IQR 0-0), while the median number of general practitioners per million population was 274 (IQR 175-410). Using an unadjusted analysis, each increase of 1 neurosurgeon per million population was associated with 1.90 fewer MVA deaths per million population (p < 0.001). On multivariate adjusted analysis, each increase of 1 neurosurgeon per million population was associated with 1.01 fewer MVA deaths per million population (p < 0.001), with a respective decrease in MVA deaths of 0.03 per million population for an increase in 1 general practitioner (p = 0.007). Rural location, persistent poverty, and low educational level were all associated with significant increases in the rate of MVA deaths.A higher population density of neurosurgeons is associated with a significant reduction in deaths from MVAs, a major cause of death nationally. This suggests that the availability of local neurosurgeons is an important factor in the overall likelihood of survival from an MVA, and therefore indicates the importance of promoting neurosurgical education and practice throughout the country.

  View details for DOI 10.3171/2012.6.JNS111281

  View details for PubMedID 22827590

• Minimally invasive tubular retractor system for adequate exposure during surgical obliteration of spinal dural arteriovenous fistulas with the aid of indocyanine green intraoperative angiography. Journal of neurosurgery. Spine Desai, A., Bekelis, K., Erkmen, K. 2012; 17 (2): 160-163

  Abstract

  Effective surgical obliteration of spinal dural arteriovenous fistulas (DAVFs) traditionally requires laminectomy or hemilaminectomy to allow intradural exposure and occlusion of the draining vein. The authors present successful treatment of a spinal DAVF by using a tubular retractor system to provide minimally invasive exposure at the L5-S1 level adequate for both microsurgical treatment and intraoperative indocyanine green angiography.

  View details for DOI 10.3171/2012.4.SPINE12152

  View details for PubMedID 22632175

• Frameless robotically targeted stereotactic brain biopsy: feasibility, diagnostic yield, and safety JOURNAL OF NEUROSURGERY Bekelis, K., Badwan, T. A., Desai, A., Roberts, D. W. 2012; 116 (5): 1002-1006

  Abstract

  Frameless stereotactic brain biopsy has become an established procedure in many neurosurgical centers worldwide. Robotic modifications of image-guided frameless stereotaxy hold promise for making these procedures safer, more effective, and more efficient. The authors hypothesized that robotic brain biopsy is a safe, accurate procedure, with a high diagnostic yield and a safety profile comparable to other stereotactic biopsy methods.This retrospective study included 41 patients undergoing frameless stereotactic brain biopsy of lesions (mean size 2.9 cm) for diagnostic purposes. All patients underwent image-guided, robotic biopsy in which the SurgiScope system was used in conjunction with scalp fiducial markers and a preoperatively selected target and trajectory. Forty-five procedures, with 50 supratentorial targets selected, were performed.The mean operative time was 44.6 minutes for the robotic biopsy procedures. This decreased over the second half of the study by 37%, from 54.7 to 34.5 minutes (p < 0.025). The diagnostic yield was 97.8% per procedure, with a second procedure being diagnostic in the single nondiagnostic case. Complications included one transient worsening of a preexisting deficit (2%) and another deficit that was permanent (2%). There were no infections.Robotic biopsy involving a preselected target and trajectory is safe, accurate, efficient, and comparable to other procedures employing either frame-based stereotaxy or frameless, nonrobotic stereotaxy. It permits biopsy in all patients, including those with small target lesions. Robotic biopsy planning facilitates careful preoperative study and optimization of needle trajectory to avoid sulcal vessels, bridging veins, and ventricular penetration.

  View details for DOI 10.3171/2012.1.JNS111746

  View details for Web of Science ID 000303088800012

  View details for PubMedID 22404667

• Magnetic resonance imaging/magnetic resonance angiography fusion technique for intraoperative navigation during microsurgical resection of cerebral arteriovenous malformations NEUROSURGICAL FOCUS Bekelis, K., Missios, S., Desai, A., Eskey, C., Erkmen, K. 2012; 32 (5)

  Abstract

  Microsurgical resection of arteriovenous malformations (AVMs) is facilitated by real-time image guidance that demonstrates the precise size and location of the AVM nidus. Magnetic resonance images have routinely been used for intraoperative navigation, but there is no single MRI sequence that can provide all the details needed for characterization of the AVM. Additional information detailing the specific location of the feeding arteries and draining veins would be valuable during surgery, and this detail may be provided by fusing MR images and MR angiography (MRA) sequences. The current study describes the use of a technique that fuses contrast-enhanced MR images and 3D time-of-flight MR angiograms for intraoperative navigation in AVM resection.All patients undergoing microsurgical resection of AVMs at the Dartmouth Cerebrovascular Surgery Program were evaluated from the surgical database. Between 2009 and 2011, 15 patients underwent surgery in which this contrast-enhanced MRI and MRA fusion technique was used, and these patient form the population of the present study.Image fusion was successful in all 15 cases. The additional data manipulation required to fuse the image sets was performed on the morning of surgery with minimal added setup time. The navigation system accurately identified feeding arteries and draining veins during resection in all cases. There was minimal imaging-related artifact produced by embolic materials in AVMs that had been preoperatively embolized. Complete AVM obliteration was demonstrated on intraoperative angiography in all cases.Precise anatomical localization, as well as the ability to differentiate between arteries and veins during AVM microsurgery, is feasible with the aforementioned MRI/MRA fusion technique. The technique provides important information that is beneficial to preoperative planning, intraoperative navigation, and successful AVM resection.

  View details for DOI 10.3171/2012.1.FOCUS127

  View details for Web of Science ID 000303418600008

  View details for PubMedID 22537133

• Surgery for Lumbar Degenerative Spondylolisthesis in Spine Patient Outcomes Research Trial SPINE Desai, A., Ball, P. A., Bekelis, K., Lurie, J., Mirza, S. K., Tosteson, T. D., Zhao, W., Weinstein, J. N. 2012; 37 (5): 406-413

  Abstract

  Retrospective review of a prospectively collected multi-institutional database.In the present analysis, we investigate the impact of incidental durotomy on outcome in patients undergoing surgery for lumbar degenerative spondylolisthesis.Surgery for lumbar degenerative spondylolisthesis has several potential complications, one of the most common of which is incidental durotomy. The effect of incidental durotomy on outcome, however, remains uncertain.Spine Patient Outcomes Research Trial cohort participants with a confirmed diagnosis of lumbar degenerative spondylolisthesis undergoing standard first-time open decompressive laminectomy, with or without fusion, were followed from baseline at 6 weeks, at 3, 6, 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Patient data from this prospectively gathered database were reviewed. As of May 2009, the mean (standard deviation [SD]) follow-up among all analyzed degenerative spondylolisthesis patients was 46.6 months (SD = 13.1) (no durotomy: 46.7 vs. had durotomy: 45.2, P = 0.49). The median (range) follow-up time among all analyzed degenerative spondylolisthesis patients was 47.6 months (SD = 2.5-84).A 10.5% incidence of durotomy was detected among the 389 patients undergoing surgery. No significant differences were observed with or without durotomy in age, race, the prevalence of smoking, diabetes and hypertension, decompression level, number of levels, or whether a fusion was performed. There were no differences in incidence of nerve root injury, postoperative mortality, additional surgeries, 36-Item Short Form Health Survey (SF-36) scores of body pain or physical function, or Oswestry Disability Index at 1, 2, 3, and 4 years.Incidental durotomy during first-time surgery for lumbar degenerative spondylolisthesis does not appear to impact outcome in affected patients.

  View details for DOI 10.1097/BRS.0b013e3182349bc5

  View details for Web of Science ID 000300872300021

  View details for PubMedID 21971123

  View details for PubMedCentralID PMC3279597

• Surgical techniques for investigating the role of the insula in epilepsy: a review NEUROSURGICAL FOCUS Desai, A., Bekelis, K., Darcey, T. M., Roberts, D. W. 2012; 32 (3)

  Abstract

  Intracranial electroencephalography monitoring of the insula is an important tool in the investigation of the insula in medically intractable epilepsy and has been shown to be safe and reliable. Several methods of placing electrodes for insular coverage have been reported and include open craniotomy as well as stereotactic orthogonal and stereotactic anterior and posterior oblique trajectories. The authors review each of these techniques with respect to current concepts in insular epilepsy.

  View details for DOI 10.3171/2012.1.FOCUS11325

  View details for Web of Science ID 000301005400007

  View details for PubMedID 22380860

• SPORT: Does Incidental Durotomy Affect Long-term Outcomes in Cases of Spinal Stenosis? NEUROSURGERY Desai, A., Ball, P. A., Bekelis, K., Lurie, J., Mirza, S. K., Tosteson, T. D., Weinstein, J. N. 2011; 69 (1): 38-44

  Abstract

  Incidental durotomy is a familiar encounter during surgery for lumbar spinal stenosis. The impact of durotomy on long-term outcomes remains a matter of debate.To determine the impact of durotomy on the long-term outcomes of patients in the Spine Patient Outcomes Research Trial (SPORT).The SPORT cohort participants with a confirmed diagnosis of spinal stenosis, without associated spondylolisthesis, undergoing standard, first-time, open decompressive laminectomy, with or without fusion, were followed up from baseline at 6 weeks, and 3, 6, and 12 months and yearly thereafter at 13 spine clinics in 11 US states. Patient data from this prospectively gathered database were reviewed. As of May 2009, the mean follow-up among all analyzed patients was 43.8 months.Four hundred nine patients underwent first-time open laminectomy with or without fusion. Thirty-seven of these patients (9%) had an incidental durotomy. No significant differences were observed with or without durotomy in age; sex; race; body mass index; the prevalence of smoking, diabetes mellitus, and hypertension; decompression level; number of levels decompressed; or whether an additional fusion was performed. The durotomy group had significantly increased operative duration, operative blood loss, and inpatient stay. There were, however, no differences in incidence of nerve root injury, mortality, additional surgeries, or primary outcomes (Short Form-36 Bodily Pain or Physical Function scores or Oswestry Disability Index) at yearly follow-ups to 4 years.Incidental durotomy during first-time lumbar laminectomy for spinal stenosis did not impact long-term outcomes in affected patients.

  View details for DOI 10.1227/NEU.0b013e3182134171

  View details for Web of Science ID 000291344700029

  View details for PubMedID 21358354

• Outcomes after incidental durotomy during first-time lumbar discectomy JOURNAL OF NEUROSURGERY-SPINE Desai, A., Ball, P. A., Bekelis, K., Lurie, J. D., Mirza, S. K., Tosteson, T. D., Weinstein, J. N. 2011; 14 (5): 647-653

  Abstract

  Incidental durotomy is an infrequent but well-recognized complication during lumbar disc surgery. The effect of a durotomy on long-term outcomes is, however, controversial. The authors sought to examine whether the occurrence of durotomy during surgery impacts long-term clinical outcome.Spine Patient Outcomes Research Trial (SPORT) participants who had a confirmed diagnosis of intervertebral disc herniation and were undergoing standard first-time open discectomy were followed up at 6 weeks and at 3, 6, and 12 months after surgery and annually thereafter at 13 spine clinics in 11 US states. Patient data from this prospectively gathered database were reviewed. As of May 2009, the mean (± SD) duration of follow-up among all of the intervertebral disc herniation patients whose data were analyzed was 41.5 ± 14.5 months (41.4 months in those with no durotomy vs 40.2 months in those with durotomy, p < 0.68). The median duration of follow-up among all of these patients was 47 months (range 1-95 months).A total of 799 patients underwent first-time lumbar discectomy. There was an incidental durotomy in 25 (3.1%) of these cases. There were no significant differences between the durotomy and no-durotomy groups with respect to age, sex, race, body mass index, herniation level or type, or the prevalence of smoking, diabetes, or hypertension. When outcome differences between the groups were analyzed, the durotomy group was found to have significantly increased operative duration, operative blood loss, and length of inpatient stay. However, there were no significant differences in incidence rates for nerve root injury, postoperative mortality, additional surgeries, or SF-36 scores for Bodily Pain or Physical Function, or Oswestry Disability Index scores at 1, 2, 3, or 4 years.Incidental durotomy during first-time lumbar discectomy does not appear to impact long-term outcome in affected patients.

  View details for DOI 10.3171/2011.1.SPINE10426

  View details for Web of Science ID 000289914100015

  View details for PubMedID 21375385

• Stereotactic depth electrode investigation of the insula in the evaluation of medically intractable epilepsy JOURNAL OF NEUROSURGERY Desai, A., Jobst, B. C., Thadani, V. M., Bujarski, K. A., Gilbert, K., Darcey, T. M., Roberts, D. W. 2011; 114 (4): 1176-1186

  Abstract

  The authors describe their experience with stereotactic implantation of insular depth electrodes in patients with medically intractable epilepsy.Between 2001 and 2009, 20 patients with epilepsy and suspected insular involvement during seizures underwent intracranial electrode array implantation at the authors' institution. All patients had either 1 or 2 insular depth electrodes placed as part of an intracranial array.A total of 29 insular depth electrodes were placed using a frontal oblique trajectory. Eleven patients had a single insular electrode placed and 8 patients had 2 insular electrodes placed unilaterally. One patient had bilateral insular electrodes implanted. Postoperative imaging demonstrated satisfactory placement in all but 1 instance, and there was no associated morbidity or mortality. Fourteen patients underwent a subsequent resection, involving the frontal lobe (9 patients), temporal lobe (4), or frontotemporal lobes (1), and of these, 11 currently have Engel Class I outcome. Two patients (10%) had seizures originating within the insula and another 5 patients (25%) demonstrated early specific insular involvement. Neither patient with an insular seizure focus went on to resection. All 5 of the patients with early specific insular involvement underwent an insula-sparing resective procedure with Engel Class I outcome in all cases.Stereotactic placement of insular electrodes via a frontal oblique approach is a safe and efficient technique for investigating insular involvement in medically intractable epilepsy. The information obtained from insular recording can be valuable for appreciating the degree of insular contribution to seizures, allowing localization to the insula or clearer implication of other sites.

  View details for DOI 10.3171/2010.9.JNS091803

  View details for Web of Science ID 000288725900045

  View details for PubMedID 20950081

• Akathisia after mild traumatic head injury Case report JOURNAL OF NEUROSURGERY-PEDIATRICS Desai, A., Nierenberg, D. W., Duhaime, A. 2010; 5 (5): 460-464

  Abstract

  The authors describe the case of a 13-year-old boy who exhibited progressive disabling motor restlessness, torticollis, urinary symptoms, and confusion following a fall from a bicycle. The differential diagnosis of this striking symptom complex in this clinical context can be problematic. In this case, the symptoms ultimately appeared most consistent with severe akathisia resulting from a single administration of haloperidol used at an outside hospital to sedate the patient prior to a head CT scan. The literature on akathisia in pediatric patients, and especially in patients following acute head injury, is reviewed, with suggestions for an approach to these symptoms in this clinical setting.

  View details for DOI 10.3171/2009.11.PEDS09389

  View details for Web of Science ID 000277131500008

  View details for PubMedID 20433258

• How long should cerebrospinal fluid cultures be held to detect shunt infections? JOURNAL OF NEUROSURGERY-PEDIATRICS Desai, A., Lollis, S. S., Missios, S., Radwan, T., Zuaro, D. E., Schwarzman, J. D., Duhaime, A. 2009; 4 (2): 184-189

  Abstract

  Infections of CSF hardware may be indolent, and some patients have received antibiotic treatment for various reasons before CSF is obtained to check for a shunt infection. At present, there are few data in the literature to guide the decision as to how long to hold CSF specimens when attempting to diagnose hardware infections, and institutions vary in the duration at which cultures are considered "final."The authors reviewed the microbiology data from CSF specimens obtained from shunts, ventriculostomies, reservoirs, and lumbar drains at their institution over a 36-month period to discover how long after collection cultures became positive. The authors also sought to discover whether this time was affected by prior treatment with antibiotics.Of 158 positive CSF specimens obtained from hardware, the time to recovery ranged between 1-10 days, with a mean of 3.02 days (SD 2.37 days, 95% CI 2.66-3.38 days). One hundred and twenty-seven positive specimens were associated with clinical infections, and approximately 25% of these grew organisms after > 3 days, with some as long as 10 days after specimens were obtained. The most common organisms grown from individual patients were coagulase-negative Staphylococcus spp (34 cultures), Propionibacterium spp (21), Bacillus spp (6), Pseudomonas aeruginosa (4), and Staphylococcus aureus (4 cultures). Mean and maximum days to recovery were different across species, with S. aureus showing the shortest and Propionibacterium spp showing the longest incubation times. There appeared to be no significant difference in the time to recovery between specimens obtained in patients who had received prior antibiotic treatment versus those who had not.A substantial number of positive CSF specimens obtained in patients with clinical infections grew bacteria after > 3 days, with some requiring as long as 10 days. Thus, a routine 10-day observation period for CSF specimens can be justified.

  View details for DOI 10.3171/2009.4.PEDS08279

  View details for Web of Science ID 000268341400017

  View details for PubMedID 19645555

• Hepatology outpatient service provision in secondary care: a study of liver disease incidence and resource costs CLINICAL MEDICINE Whalley, S., Puvanachandra, P., Desai, A., Kennedy, H. 2007; 7 (2): 119-124

  Abstract

  This paper discusses the annual incidence of liver disease and resource costs in providing a hepatology service for all new outpatient referrals to a secondary care setting. In a retrospective study, we found that 200 patients (1 in 1,000 of the West Suffolk population) with a mean age of 52 years were referred per year. One-third of patients had cirrhosis (almost half due to alcohol). Annual incidence (per 100,000 population) were as follows: non-alcoholic fatty liver disease (29: of which 23.5 non-cirrhotic and 5.5 cirrhotic), hepatitis C (25), hepatitis B (3), alcohol-related cirrhosis (12.5), primary biliary cirrhosis (3.5), autoimmune hepatitis (3), primary sclerosing cholangitis (2), haemochromatosis (2), hepatocellular carcinoma (1.5) and oesophageal variceal haemorrhage (6.5). Using national indicative tariffs, the total annual hepatology budget was 130K pounds (58K pounds for resources and 72K pounds for clinic attendances). The greatest resource expenditure was on endoscopy (almost half for oesophageal varices) and radiological imaging (one-third of the total budget). These findings will help inform commissioners in hepatology service funding.

  View details for Web of Science ID 000246059500011

  View details for PubMedID 17491498

• Can Asperger syndrome be diagnosed at 26 months old? A genetic high-risk single-case study JOURNAL OF CHILD NEUROLOGY Baron-Cohen, S., Scott, F., Wheelwright, S., Johnson, M., Bisarya, D., Desai, A., Ahluwalia, J. 2006; 21 (4): 351-356

  Abstract

  Asperger syndrome, a heritable condition entailing empathy deficits together with unusually narrow interests in individuals of normal or even above-average intelligence, was recognized only recently. Here we report the first-ever prospective study of a child born to two adults with a formal diagnosis of Asperger syndrome. The child's parents are both scientists (a mathematician and a chemist). The aim of study 1 was to test if the child also developed Asperger syndrome, given the heritability of the condition, and if Asperger syndrome can be detected at 26 months. At 18 months, the child was given the Checklist for Autism in Toddlers, and at 26 months, she was assessed diagnostically for autism spectrum conditions using the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observational Scale. The child failed the Checklist for Autism in Toddlers at 18 months and met the criteria for Asperger syndrome at 26 months. This single case is consistent with the hypersystemizing, assortative mating theory of autism. This theory requires further testing with large samples. This study also demonstrates that Asperger syndrome can be diagnosed by age 26 months. The aim of study 2 was to test if dyadic eye contact in infancy is intact in a child later diagnosed with Asperger syndrome. The same child's eye contact was measured at three time points (3, 6, and 9 months) over her first year of life and compared with that of age-matched controls. Although the child had low rates of eye contact at 6 months, it was within the normal range at all three points in the first year of life. We conclude that low levels of eye contact are not predictive of later development of Asperger syndrome.

  View details for DOI 10.2310/7010.2006.00072

  View details for Web of Science ID 000238002800019

  View details for PubMedID 16900937

• Dissociable aspects of performance on the 5-choice serial reaction time task following lesions of the dorsal anterior cingulate, infralimbic and orbitofrontal cortex in the rat: differential effects on selectivity, impulsivity and compulsivity BEHAVIOURAL BRAIN RESEARCH Chudasama, Y., Passetti, F., Rhodes, S. E., Lopian, D., Desai, A., Robbins, T. W. 2003; 146 (1-2): 105-119

  Abstract

  It is becoming increasingly apparent that multiple functions of the frontal cortex such as inhibitory control and executive attention are likely sustained by its functionally distinct and interacting sub-regions but the precise localization of dissociable executive processes has proved difficult and controversial. In the present series of studies, we investigated the behavioural effects of bilateral excitotoxic lesions of different regions of the rat neocortex in the 5-choice serial reaction time task. Whereas lesions of the dorsal anterior cingulate cortex (ACC) impaired performance of the task as revealed by a reduction in discriminative accuracy, lesions made to distinct ventral regions of the frontal cortex showed selective deficits in inhibitory measures of control. Specifically, the infralimbic lesion produced increases in premature responding that was accompanied by fast response latencies. By comparison, the orbitofrontal lesion showed perseverative tendencies particularly when the inter-trial interval was made long and unpredictable, a challenge that would normally promote premature responding instead. These different behavioural effects following dorsal and ventral lesions of the rodent frontal cortex signifies the integrity of the frontal cortex in multiple executive mechanisms that work independently and complementarily by which performance is optimized. Furthermore, these data provide new insights into the functional organization of the rodent frontal cortex with a particular emphasis on localization of function.

  View details for DOI 10.1016/j.bbr.2003.09.020

  View details for Web of Science ID 000187240600011

  View details for PubMedID 14643464