Publications

2024

Ramirez-Velandia, Felipe, Kasuni H Ranawaka, Aryan Wadhwa, Mira Salih, Thomas B Fodor, Tzak S Lau, Niels Pacheco-Barrios, et al. (2024) 2024. “Comparison of Postoperative Seizures Between Burr-Hole Evacuation and Craniotomy in Patients With Nonacute Subdural Hematomas: A Bi-Institutional Propensity Score-Matched Analysis.”. Neurosurgery. https://doi.org/10.1227/neu.0000000000003046.

BACKGROUND AND OBJECTIVES: Postoperative seizures are a common complication after surgical drainage of nonacute chronic subdural hematomas (SDHs). The literature increasingly supports the use of prophylactic antiepileptic drugs for craniotomy, a procedure that is often associated with larger collections and worse clinical status at admission. This study aimed to compare the incidence of postoperative seizures in patients treated with burr-hole drainage and those treated with craniotomy through propensity score matching (PSM). METHODS: A retrospective cohort analysis was conducted on patients with surgical drainage of nonacute SDHs (burr-holes and craniotomies) between January 2017 to December 2021 at 2 academic institutions in the United States. PSM was performed by controlling for age, subdural thickness, subacute component, and preoperative Glasgow Coma Scale. Seizure rates and accompanying abnormalities on electroencephalographic tracing were evaluated postmatching. RESULTS: A total of 467 patients with 510 nonacute SDHs underwent 474 procedures, with 242 burr-hole evacuations (51.0%) and 232 craniotomies (49.0%). PSM resulted in 62 matched pairs. After matching, univariate analysis revealed that burr-hole evacuations exhibited lower rates of seizures (1.6% vs 11.3%; P = .03) and abnormal electroencephalographic findings (0.0% vs 4.8%; P = .03) compared with craniotomies. No significant differences were observed in postoperative Glasgow Coma Scale (P = .77) and length of hospital stay (P = .61). CONCLUSION: Burr-hole evacuation demonstrated significantly lower seizure rates than craniotomy using a propensity score-matched analysis controlling for significant variables.

Filo, Jean, Mira Salih, Omar Alwakaa, Felipe Ramirez Velandia, Max Shutran, Rafael A Vega, Martina Stippler, et al. (2024) 2024. “Factors Associated With Extended Hospitalization in Patients Who Had Adjuvant Middle Meningeal Artery Embolization After Conventional Surgery for Chronic Subdural Hematomas.”. World Neurosurgery. https://doi.org/10.1016/j.wneu.2024.06.011.

BACKGROUND: This study aims to evaluate the length of stay (LOS) in patients who had adjunct middle meningeal artery embolization (MMAE) for chronic subdural hematoma (cSDH) after conventional surgery and determine the factors influencing the LOS in this population. METHODS: A retrospective review of 107 cases with MMAE after conventional surgery between September 2018 and January 2024 was performed. Factors associated with prolonged LOS were identified through univariable and multivariable analyses. RESULTS: The median LOS for MMAE after conventional surgery was 9 days (IQR = 6 - 17), with a 3-day interval between procedures (IQR = 2 - 5). Among 107 patients, 58 stayed ≤9 days, while 49 stayed longer. Univariable analysis showed the interval between procedures, type of surgery, MMAE sedation, and the number of complications associated with prolonged LOS. Multivariable analysis confirmed longer intervals between procedures (OR=1.52; p<0.01), ≥ 2 medical complications (OR=13.34; p=0.01), and neurological complications (OR=5.28; p=0.05) were independent factors for lengthier hospitalizations. There was a trending association between general anesthesia during MMAE and prolonged LOS (p=0.07). Subgroup analysis revealed diabetes (OR=5.25; p=0.01) and ≥ 2 medical complications (OR=5.21; p=0.03) correlated with a LOS over 20 days, the 75(th) percentile in our cohort. CONCLUSION: The interval between procedures and the number of medical and neurological complications were strongly associated with prolonged LOS in patients who had adjunct MMAE after open surgery. Reducing the interval between the procedures and potentially performing both under one anesthetic may decrease the burden on patients and shorten their hospitalizations.

Blitz, Sarah E, Samantha E Hoffman, Martina Stippler, and Kristin Huntoon. (2025) 2024. “Differential Time-To-Promotion Trajectories Among Female and Male NeurosurgeonsContribute to Gender Disparities in Academic Rank Achievement.”. World Neurosurgery 183: 157-63. https://doi.org/10.1016/j.wneu.2023.12.081.
OBJECTIVE: Despite the increasing representation of females in neurosurgical training, the fraction of female to male neurosurgeons decreases dramatically as faculty rank (Assistant, Associate, or Full Professor) increases. To assess this discrepancy, we quantified self-reported time-to-promotion trajectories for female and male neurosurgeons holding academic appointments. METHODS: In this cross-sectional institutional review board (IRB)-approved study, 147 female and 84 male neurosurgeons currently holding faculty positions in the US were contacted via email and invited to complete an anonymous, standardized survey. Respondents provided the calendar year of postgraduate training completion, promotion to different faculty ranks, geographic region of current practice (Western, Midwest, Southern, Northeast), and practice subspecialty. RESULTS: The response rate was 44.2% for females and 59.5% for males, with 114 participants included (65 female, 49 male). On average, female neurosurgeons required 25% longer to become an Associate Professor (P = 0.017), 34% longer to become a Full Professor (P = 0.004), 37% longer for promotion from Assistant to Associate Professor (P 0.001), and 32% longer from Assistant to Full Professor (P = 0.012). Promotion timelines did not vary by region or specialty among male and female cohorts. Linear regressions revealed that female neurosurgeons with more recent training completion experienced shorter time-to-promotion to Associate and Full Professor compared to females of earlier generations (P = 0.005 and 0.001, respectively), while male timelines remained stable. CONCLUSIONS: This study identifies a significant delay in time-to-promotion for female neurosurgeons compared to their male counterparts. Investigation and standardization of promotion timelines are necessary to ensure meaningful representation gains from the increased number of women entering neurosurgical training.
Pyne, Sarah, Garry Barton, David Turner, Harry Mee, Barbara A Gregson, Angelos G Kolias, Carole Turner, et al. (2025) 2024. “Cost-Effectiveness of Craniotomy versus Decompressive Craniectomy for UK Patientswith Traumatic Acute Subdural Haematoma.”. BMJ Open 14 (6): e085084. https://doi.org/10.1136/bmjopen-2024-085084.
OBJECTIVE: To estimate the cost-effectiveness of craniotomy, compared with decompressive craniectomy (DC) in UK patients undergoing evacuation of acute subdural haematoma (ASDH). DESIGN: Economic evaluation undertaken using health resource use and outcome data from the 12-month multicentre, pragmatic, parallel-group, randomised, Randomised Evaluation of Surgery with Craniectomy for Patients Undergoing Evacuation-ASDH trial. SETTING: UK secondary care. PARTICIPANTS: 248 UK patients undergoing surgery for traumatic ASDH were randomised to craniotomy (N=126) or DC (N=122). INTERVENTIONS: Surgical evacuation via craniotomy (bone flap replaced) or DC (bone flap left out with a view to replace later: cranioplasty surgery). MAIN OUTCOME MEASURES: In the base-case analysis, costs were estimated from a National Health Service and Personal Social Services perspective. Outcomes were assessed via the quality-adjusted life-years (QALY) derived from the EuroQoL 5-Dimension 5-Level questionnaire (cost-utility analysis) and the Extended Glasgow Outcome Scale (GOSE) (cost-effectiveness analysis). Multiple imputation and regression analyses were conducted to estimate the mean incremental cost and effect of craniotomy compared with DC. The most cost-effective option was selected, irrespective of the level of statistical significance as is argued by economists. RESULTS: In the cost-utility analysis, the mean incremental cost of craniotomy compared with DC was estimated to be -\pounds5520 (95% CI -\pounds18 060 to \pounds7020) with a mean QALY gain of 0.093 (95% CI 0.029 to 0.156). In the cost-effectiveness analysis, the mean incremental cost was estimated to be -\pounds4536 (95% CI -\pounds17 374 to \pounds8301) with an OR of 1.682 (95% CI 0.995 to 2.842) for a favourable outcome on the GOSE. CONCLUSIONS: In a UK population with traumatic ASDH, craniotomy was estimated to be cost-effective compared with DC: craniotomy was estimated to have a lower mean cost, higher mean QALY gain and higher probability of a more favourable outcome on the GOSE (though not all estimated differences between the two approaches were statistically significant). ETHICS: Ethical approval for the trial was obtained from the North West-Haydock Research Ethics Committee in the UK on 17 July 2014 (14/NW/1076). TRIAL REGISTRATION NUMBER: ISRCTN87370545.
Stippler, Martina, Sarah E Blitz, Carolyn Quinsey, David Limbrick, Richard Byrne, Greg Zipfel, and Nathan R Selden. (2025) 2024. “Active Teaching Techniques Using Virtual Didactics: Novel Experience From ANational Neurosurgery Resident Course.”. Journal of Surgical Education 81 (2): 312-18. https://doi.org/10.1016/j.jsurg.2023.11.006.
OBJECTIVE: To investigate the attitudes of neurosurgery residents regarding active teaching techniques and virtual didactics based on a national neurosurgery resident sample. We also evaluated the relative cost and time commitment required for faculty participation in virtual versus in-person resident courses. DESIGN: The Society of Neurological Surgeons (SNS) national junior resident courses (JRCs) were reformatted for active teaching in a virtual setting in 2020 due to the COVID-19 pandemic. We analyzed course evaluations from the virtual 2020 courses in comparison to the 2019 in-person SNS JRCs. We also compared course budgets and agendas from these courses to identify comparative costs and the time commitment for faculty participation using these 2 course models. SETTING: Survey of nationwide participants in virtual junior resident courses. PARTICIPANTS: A total of 122 residents from 80 ACGME neurosurgery residency training programs attended the 2020 virtual JRC. RESULTS: The survey response rate of attendees was 36%. In-class engagement was thought to be good to great by 73% to 80% of the virtual learners. In-class activities and active learning techniques also were evaluated positively by 61% to 82% of respondents. Expenses were significantly lower for the virtual course, at $118 per course participant, than for the in-person course ($2722 per participant). There also was a 97.3% reduction of faculty hours and a 97.6% reduction of faculty cost for the virtual JRC compared to the in-person course. CONCLUSIONS: Neurosurgeon residents embraced the active teaching techniques used to teach portions of the prepandemic JRCs in a virtual format. Other aspects of the course curriculum could not be replicated virtually. Virtual courses were dramatically less expensive to produce, used fewer faculty teachers and required less time per faculty member. The data from this study may inform the choice of active teaching techniques for other neurosurgery residency and continuing medical education courses to optimize learner engagement and participant satisfaction in the virtual setting. We recommend that the curriculum of in-person courses emphasize hands-on, experiential learning and professional enculturation that cannot be recreated in the virtual space. Curricular elements suitable to virtual learning should take advantage of lower costs, reduced faculty time requirements, and scalability. They should also utilize active teaching techniques to improve learner engagement.

2023

Salih, M, M Shutran, M Young, R A Vega, M Stippler, E Papavassiliou, R L Alterman, et al. 2023. “Reduced Recurrence of Chronic Subdural Hematomas Treated With Open Surgery Followed by Middle Meningeal Artery Embolization Compared to Open Surgery Alone: A Propensity Score–matched Analysis”. J. Neurosurg. 139 (1): 124-30. https://doi.org/10.3171/2022.11.JNS222024.
OBJECTIVE Middle meningeal artery embolization (MMAE) is an emerging endovascular treatment technique with proven promising results for chronic subdural hematomas (cSDHs). MMAE as an adjunct to open surgery is being utilized with the goal of preventing the recurrence of cSDH. However, the efficacy of MMAE following surgical evacuation of cSDH has not been clearly demonstrated. The authors sought to compare the outcomes of open surgery followed by MMAE versus open surgery alone. METHODS Patients who underwent surgical evacuation alone (open surgery–alone group) or MMAE along with open surgery for cSDH (adjunctive MMAE group) were identified at the authors institution. Two balanced groups were obtained through propensity score matching. Primary outcomes included recurrence risk and reintervention rate. Secondary outcomes included decrease in hematoma size and modified Rankin Scale (mRS) score at last follow-up. Variables in the two groups were compared by use of the Mann-Whitney U-test, paired-sample t-test, and Fisher s exact test. RESULTS A total of 345 cases of open surgery alone and 52 cases of open surgery with adjunctive MMAE were identified. After control for subjective confounders, 146 patients treated with open surgery alone and 41 with adjunctive MMAE following open surgery with drain placement were included in the analysis. Before matching, the rebleeding risk and reintervention rate for open surgery trended higher in the open surgery alone than the open surgery plus MMAE group (14.4% vs 7.3%, p = 0.18; and 11.6% vs 4.9%, p = 0.17, respectively). No significant differences were seen in duration of radiographic or clinical follow-ups or decreases in hematoma size and mRS score at last follow-up. After one-to-one nearest neighbor propensity score matching, 26 pairs of cases were compared for outcomes. Rates of recurrence (7.7% vs 30.8%, p = 0.038) and overall reintervention (3.8% vs 23.1%, p = 0.049) after open surgery were found to be significantly lower in the adjunctive MMAE group than the open surgery–alone group. With one-to-many propensity score matching, 76 versus 37 cases were compared for open surgery alone versus adjunctive MMAE following open surgery. Similarly, the adjunctive MMAE group had significantly lower rates of recurrence (5.4% vs 19.7%, p = 0.037) and overall reintervention (2.7% vs 14.5%, p = 0.049). CONCLUSIONS Adjunctive MMAE following open surgery can lower the recurrence risks and reintervention rates for cSDH.
Powers, Andrew Y, David C Chang, Martina Stippler, Efstathios Papavassiliou, and Ziev B Moses. (2025) 2023. “Public Health Insurance, Frailty, and Lack of Home Support Predict Rehabdischarge Following Elective Anterior Cervical Discectomy and Fusion.”. The Spine Journal : Official Journal of the North American Spine Society 23 (12): 1830-37. https://doi.org/10.1016/j.spinee.2023.08.018.
BACKGROUND CONTEXT: Anterior cervical discectomy and fusion (ACDF) is a commonly-performed and generally well-tolerated procedure used to treat cervical disc herniation. Rarely, patients require discharge to inpatient rehab, leading to inconvenience for the patient and increased healthcare expenditure for the medical system. PURPOSE: The objective of this study was to create an accurate and practical predictive model for, as well as delineate associated factors with, rehab discharge following elective ACDF. STUDY DESIGN: This was a retrospective, single-center, cohort study. PATIENT SAMPLE: Patients who underwent ACDF between 2012 and 2022 were included. Those with confounding diagnoses or who underwent concurrent, staged, or nonelective procedures were excluded. OUTCOME MEASURES: Primary outcomes for this study included measurements of accuracy for predicting rehab discharge. Secondary outcomes included associations of variables with rehab discharge. METHODS: Current Procedural Terminology codes identified patients. Charts were reviewed to obtain additional demographic and clinical characteristics on which an initial univariate analysis was performed. Two logistic regression and two machine learning models were trained and evaluated on the data using cross-validation. A multimodel logistic regression was implemented to analyze independent variable associations with rehab discharge. RESULTS: A total of 466 patients were included in the study. The logistic regression model with minimum corrected Akaike information criterion score performed best overall, with the highest values for area under the receiver operating characteristic curve (0.83), Youden s J statistic (0.71), balanced accuracy (85.7%), sensitivity (90.3%), and positive predictive value (38.5%). Rehab discharge was associated with a modified frailty index of 2 (p=.007), lack of home support (p=.002), and having Medicare or Medicaid insurance (p=.007) after correction for multiple hypotheses. CONCLUSIONS: Nonmedical social determinants of health, such as having public insurance or a lack of support at home, may play a role in rehab discharge following elective ACDF. In combination with the modified frailty index and other variables, these factors can be used to predict rehab discharge with high accuracy, improving the patient experience and reducing healthcare costs.
Salih, Mira, Michael Young, Max Shutran, Martina Stippler, Efstathios Papavassiliou, Ron L Alterman, Ajith J Thomas, Philipp Taussky, Justin Moore, and Christopher S Ogilvy. (2025) 2023. “Effect of Long-Term Anticoagulant Therapy on the Outcome of Chronic Subduralhematoma: A Propensity Score-Matched Analysis.”. Journal of Neurosurgery 139 (1): 194-200. https://doi.org/10.3171/2022.11.JNS222022.
OBJECTIVE: Chronic subdural hematomas (cSDHs) are particularly common in older adults who have increased risk of falls and the conditions that require anticoagulants (ACs). In such cases, clinicians are often left with the dilemma of co-managing the cSDH and the ongoing need for ACs. METHODS: Patients who underwent surgical management for cSDH at the authors institution between January 2006 and June 2022 were identified. Propensity score-matched analysis was used to obtain a balance in patients who were on ACs before the procedure versus those who were not, and in patients who were on ACs postprocedure versus those who were not. Length of hospitalization, periprocedural complications, reintervention rate during the same admission, rebleeding risk, and reintervention rates after discharge were compared. RESULTS: In total, 104 patients were on long-term ACs before the procedure, whereas 372 were not. After matching, 55 pairs were included in the analysis. Postprocedure, 74 patients were started on long-term ACs; the rest were not. A total of 49 patients in each group were then included in the analysis after matching. Comparing the preprocedure AC group with the non-AC group, no significant differences were found in length of hospitalization (8.5 ± 6.7 days vs 8.1 ± 7.7 days, p = 0.75), periprocedural complications (7.3% vs 7.3%, p > 0.99), or reintervention during the same admission (1.8% vs 5.5%, p = 0.31). In the comparison of postprocedure AC and non-AC groups, no significant differences were seen in recurrence rate (8.2% vs 14.3%, p = 0.52), reintervention rate after discharge (4.1% vs 14.3%, p = 0.16), or disability (i.e., mRS ≤ 2; 83.7% vs 89.8%, p = 0.55). CONCLUSIONS: Being treated with long-term ACs before cSDH procedures does not affect length of hospitalization, periprocedural complications, or reintervention during the same admission. Similarly, administration of long-term ACs after a procedure for cSDH does not increase rebleeding risk or reintervention rate. Patients who are on long-term ACs can have similar interventions to those who are not on ACs. In addition, it is safe to restart patients on AC agents in a 7- to 14-day window after admission for cSDH with or without acute/subacute components.
Salih, Mira, Michael Young, Alfonso Garcia, Martina Stippler, Efstathios Papavassiliou, Ron L Alterman, Ajith J Thomas, Philipp Taussky, Justin Moore, and Christopher S Ogilvy. (2025) 2023. “Outcome of Chronic Subdural Hematoma Intervention in Patients on Long-TermAntiplatelet Therapy-A Propensity Score Matched Analysis.”. Neurosurgery 93 (3): 586-91. https://doi.org/10.1227/neu.0000000000002452.
BACKGROUND: Patients presenting with chronic subdural hematomas (cSDHs) and on antiplatelet medications for various medical conditions often complicate surgical decision making. OBJECTIVE: To evaluate risks of preprocedural and postprocedural antiplatelet use in patients with cSDHs. METHODS: Patients with cSDH who were treated between January 2006 and February 2022 at a single institution with surgical intervention were identified. A propensity score matching analysis was then performed analyzing length of hospitalization, periprocedural complications, reintervention rate, rebleeding risk, and reintervention rates. RESULTS: Preintervention, 178 patients were on long-term antiplatelet medication and 298 were not on any form of antiplatelet. Sixty matched pairs were included in the propensity score analysis. Postintervention, 88 patients were resumed on antiplatelet medication, whereas 388 patients did not have resumption of antiplatelets. Fifty-five pairs of matched patients were included in the postintervention propensity score analysis. No significant differences were found in length of hospitalization (7.8 ± 4.2 vs 6.8 ± 5.4, P = .25), procedural complications (3.3% vs 6.7%, P = .68), or reintervention during the same admission (3.3% vs 5%, P = 1). No significant differences were seen in recurrence rate (9.1% vs 10.9%, P = 1) or reintervention rate after discharge (7.3% vs 9.1%, P = 1) in the postintervention group. CONCLUSION: Preintervention antiplatelet medications before cSDH treatment do not affect length of hospitalization, periprocedural complications, or reintervention. Resumption of antiplatelet medication after cSDH procedures does not increase the rebleeding risk or reintervention rate.
Blitz, Sarah E, Leila A Mashouf, Amber Nieves, Jason Matos, Michael Yaffe, Roger B Davis, Ron L Alterman, and Martina Stippler. (2025) 2023. “Prevalence and Predictors of Inappropriate Antithrombotic Prescription InPatients Presenting With Traumatic Brain Injury.”. Neurosurgery 93 (5): 1019-25. https://doi.org/10.1227/neu.0000000000002540.
BACKGROUND AND OBJECTIVES: A growing proportion of the US population is on antithrombotic therapy (AT), most significantly within the older subpopulation. Decision to use AT is a balance between the intended benefits and known bleeding risk, especially after traumatic brain injury (TBI). Preinjury inappropriate AT offers no benefit for the patient and also increases the risk of intracranial hemorrhage and worse outcome in the setting of TBI. Our objective was to examine the prevalence and predictors of inappropriate AT among patients presenting with TBI to a Level-1 Trauma Center. METHODS: A retrospective chart review was performed on all patients with TBI and preinjury AT who presented to our institution between January 2016 and September 2020. Demographic and clinical data were collected. Appropriateness of AT was determined through established clinical guidelines. Clinical predictors were determined by logistic regression. RESULTS: Of 141 included patients, 41.8% were female (n = 59) and the average age (mean ± SD) was 80.6 ± 9.9. The prescribed antithrombotic agents included aspirin (25.5%, n = 36), clopidogrel (22.7%, n = 32), warfarin (46.8%, n = 66), dabigatran (2.1%, n = 3), rivaroxaban (Janssen) (10.6%, n = 15), and apixaban (Bristol-Myers Squibb Co.) (18.4%, n = 26). The indications for AT were atrial fibrillation (66.7%, n = 94), venous thromboembolism (13.4%, n = 19), cardiac stent (8.5%, n = 12), and myocardial infarction/residual coronary disease (11.3%, n = 16). Inappropriate antithrombotic therapy use varied significantly by antithrombotic indication ( P .001) with the highest rates seen with venous thromboembolism. Predictive factors also include age ( P = .005) with higher rates younger than 65 years and older than 85 years and female sex ( P = .049). Race and antithrombotic agent were not significant predictors. CONCLUSION: Overall, 1 in 10 patients presenting with TBI were found to be on inappropriate AT. Our study is the first to describe this problem and warrants investigation into possible workflow interventions to prevent post-TBI continuation of inappropriate AT.