All Publications

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


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

    View details for DOI 10.1016/j.wnsx.2024.100382

    View details for PubMedID 38756754

    View details for PubMedCentralID PMC11097082

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


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

    View details for DOI 10.1016/j.xnsj.2024.100321

    View details for PubMedID 38741936

  • Gating of Opioid Withdrawal Aversion by a Unique Class of Neurons in the Nucleus Accumbens Tucciarone, J., Pomrenze, M., Baek, J., Zhang, Z., Touponse, G., Shank, A., Neumann, P., Eshel, N., Malenka, R. SPRINGERNATURE. 2023: 492-493
  • Demographic and Socioeconomic Trends in Cervical Fusion Utilization from 2004 through 2021 and the COVID-19 Pandemic. World neurosurgery Wu, J. Y., Touponse, G. C., Theologitis, M., Ahmad, H. S., Zygourakis, C. C. 2023


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

    View details for DOI 10.1016/j.wneu.2023.11.055

    View details for PubMedID 38000672

  • Striatal dopamine integrates cost, benefit, and motivation. Neuron Eshel, N., Touponse, G. C., Wang, A. R., Osterman, A. K., Shank, A. N., Groome, A. M., Taniguchi, L., Cardozo Pinto, D. F., Tucciarone, J., Bentzley, B. S., Malenka, R. C. 2023


    Striatal dopamine (DA) release has long been linked to reward processing, but it remains controversial whether DA release reflects costs or benefits and how these signals vary with motivation. Here, we measure DA release in the nucleus accumbens (NAc) and dorsolateral striatum (DLS) while independently varying costs and benefits and apply behavioral economic principles to determine a mouse's level of motivation. We reveal that DA release in both structures incorporates both reward magnitude and sunk cost. Surprisingly, motivation was inversely correlated with reward-evoked DA release. Furthermore, optogenetically evoked DA release was also heavily dependent on sunk cost. Our results reconcile previous disparate findings by demonstrating that striatal DA release simultaneously encodes cost, benefit, and motivation but in distinct manners over different timescales. Future work will be necessary to determine whether the reduction in phasic DA release in highly motivated animals is due to changes in tonic DA levels.

    View details for DOI 10.1016/j.neuron.2023.10.038

    View details for PubMedID 38016471

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


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

    View details for DOI 10.1097/BSD.0000000000001533

    View details for PubMedID 37691156

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


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

    View details for DOI 10.1210/jendso/bvad085

    View details for PubMedID 37388575

    View details for PubMedCentralID PMC10306270

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


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

    View details for DOI 10.1227/neu.0000000000002322

    View details for PubMedID 36606803

  • Behavioral Economics of Striatal Dopamine Eshel, N., Touponse, G., Wang, A., Osterman, A., Shank, A., Groome, A., Taniguchi, L., Pinto, D., Tucciarone, J., Bentzley, B., Malenka, R. SPRINGERNATURE. 2022: 519-520
  • Evidence-based surgery for laparoscopic cholecystectomy. Surgery open science Fisher, A. T., Bessoff, K. E., Khan, R. I., Touponse, G. C., Yu, M. M., Patil, A. A., Choi, J., Stave, C. D., Forrester, J. D. 2022; 10: 116-134


    Laparoscopic cholecystectomy is frequently performed for acute cholecystitis and symptomatic cholelithiasis. Considerable variation in the execution of key steps of the operation remains. We conducted a systematic review of evidence regarding best practices for critical intraoperative steps for laparoscopic cholecystectomy.We identified 5 main intraoperative decision points in laparoscopic cholecystectomy: (1) number and position of laparoscopic ports; (2) identification of cystic artery and duct; (3) division of cystic artery and duct; (4) indications for subtotal cholecystectomy; and (5) retrieval of the gallbladder. PubMed, EMBASE, and Web of Science were queried for relevant studies. Randomized controlled trials and systematic reviews were included for analysis, and evidence quality was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation framework.Fifty-two articles were included. Although all port configurations were comparable from a safety standpoint, fewer ports sometimes resulted in improved cosmesis or decreased pain but longer operative times. The critical view of safety should be obtained for identification of the cystic duct and artery but may be obtained through fundus-first dissection and augmented with cholangiography or ultrasound. Insufficient evidence exists to compare harmonic-shear, clipless ligation against clip ligation of the cystic duct and artery. Stump closure during subtotal cholecystectomy may reduce rates of bile leak and reoperation. Use of retrieval bag for gallbladder extraction results in minimal benefit. Most studies were underpowered to detect differences in incidence of rare complications.Key operative steps of laparoscopic cholecystectomy should be informed by both compiled data and surgeon preference/patient considerations.

    View details for DOI 10.1016/j.sopen.2022.08.003

    View details for PubMedID 36132940

    View details for PubMedCentralID PMC9483801

  • Scoping review of traumatic hemothorax: Evidence and knowledge gaps, from diagnosis to chest tube removal. Surgery Choi, J., Villarreal, J., Andersen, W., Min, J. G., Touponse, G., Wong, C., Spain, D. A., Forrester, J. D. 2021


    BACKGROUND: Traumatic hemothorax is a common injury that invites diagnostic and management strategy debates. Evidence-based management has been associated with improved care efficiency. However, the literature abounds with long-debated, re-emerging, and new questions. We aimed to consolidate up-to-date evidence on traumatic hemothoraces, focusing on clinical conundra debated in literature.METHODS: We conducted a scoping review of 21 clinical conundra in traumatic hemothorax diagnosis and management according to PRISMA-ScR guidelines. Experimental and observational studies evaluating patients (aged ≥18 years) with traumatic hemothoraces were identified through database searches (PubMed, EMBASE, Web of Science, Cochrane Library; database inception to Sep, 26 2020) and bibliography reviews of selected articles. Three reviewers screened and selected articles using standardized forms.RESULTS: We screened 1,440 articles for eligibility, of which 71 met criteria for synthesis. The review comprises 6 sections: (1) Presumptive antibiotics before tube thoracostomy; (2) Initial diagnostic and intervention decisions; (3) Chest tubes; (4) Retained hemothoraces; (5) Delayed hemothoraces; and (6) Chest tube removal). The 21 conundra across these sections follow the format of a question, our recommendation based on interpretation of available evidence, and succinct rationale. Rationale sections detail knowledge gaps and opportunities for future research.CONCLUSION: Even practices engrained into surgical dogma, such as obtaining chest x-rays after inserting or removing chest tubes and mandating operation for patients who develop chest tube output above a certain threshold, deserve re-evaluation. Some knowledge gaps require rigorous future investigation; sound clinical judgment can likely supplement others.

    View details for DOI 10.1016/j.surg.2021.03.030

    View details for PubMedID 33888318

  • Practical Computer Vision Application to Compute Total Body Surface Area Burn: Reappraising a Fundamental Burn Injury Formula in the Modern Era. JAMA surgery Choi, J., Patil, A., Vendrow, E., Touponse, G., Aboukhater, L., Forrester, J. D., Spain, D. A. 2021


    Critical burn management decisions rely on accurate percent total body surface area (%TBSA) burn estimation. Existing %TBSA burn estimation models (eg, Lund-Browder chart and rule of nines) were derived from a linear formula and a limited number of individuals a century ago and do not reflect the range of body habitus of the modern population.To develop a practical %TBSA burn estimation tool that accounts for exact burn injury pattern, sex, and body habitus.This population-based cohort study evaluated the efficacy of a computer vision algorithm application in processing an adult laser body scan data set. High-resolution surface anthropometry laser body scans of 3047 North American and European adults aged 18 to 65 years from the Civilian American and European Surface Anthropometry Resource data set (1998-2001) were included. Of these, 1517 participants (49.8%) were male. Race and ethnicity data were not available for analysis. Analyses were conducted in 2020.The contributory %TBSA for 18 body regions in each individual. Mobile application for real-time %TBSA burn computation based on sex, habitus, and exact burn injury pattern.Of the 3047 individuals aged 18 to 65 years for whom body scans were available, 1517 (49.8%) were male. Wide individual variability was found in the extent to which major body regions contributed to %TBSA, especially in the torso and legs. Anterior torso %TBSA increased with increasing body habitus (mean [SD], 15.1 [0.9] to 19.1 [2.0] for male individuals; 15.1 [0.8] to 18.0 [1.7] for female individuals). This increase was attributable to increase in abdomen %TBSA (mean [SD], 5.3 [0.7] to 8.7 [1.8]) among male individuals and increase in abdomen (mean [SD], 4.6 [0.6] to 6.8 [1.7]) and pelvis (mean [SD], 1.5 [0.2] to 2.9 [0.9]) %TBSAs among female individuals. For most body regions, Lund-Browder chart and rule of nines estimates fell outside the population's measured interquartile ranges. The mobile application tested in this study, Burn Area, facilitated accurate %TBSA burn computation based on exact burn injury pattern for 10 sex and body habitus-specific models.Computer vision algorithm application to a large laser body scan data set may provide a practical tool that facilitates accurate %TBSA burn computation in the modern era.

    View details for DOI 10.1001/jamasurg.2021.5848

    View details for PubMedID 34817552