Publications

2021

Enríquez-Marulanda, Alejandro, Santiago Gomez-Paz, Mohamed M Salem, Akashleena Mallick, Rouzbeh Motiei-Langroudi, J E Arle, Martina Stippler, et al. (2025) 2021. “Middle Meningeal Artery Embolization Versus Conventional Treatment of ChronicSubdural Hematomas.”. Neurosurgery 89 (3): 486-95. https://doi.org/10.1093/neuros/nyab192.
BACKGROUND: Middle meningeal artery (MMA) embolization is an emerging minimally invasive endovascular technique for chronic subdural hematoma (cSDH). Currently, limited literature exists on its safety and efficacy compared with conventional treatment (open-surgical-evacuation-only). OBJECTIVE: To compare MMA embolization to conventional treatment. METHODS: Retrospective analysis of patients with cSDHs treated with MMA embolization in a single center from 2018 to 2019 was performed. Comparisons were made with a historical conventional treatment cohort from 2006 to 2016. Propensity score matching analysis was used to assemble a balanced group of subjects. RESULTS: A total of 357 conventionally treated cSDH and 45 with MMA embolization were included. After balancing with propensity score matching, a total of 25 pairs of cSDH were analyzed. Comparing the embolization with the conventional treatment group yielded no significant differences in complications (4% vs 4%; P > .99), clinical improvement (82.6% vs 83.3%; P = .95), cSDH recurrence (4.3% vs 21.7%; P = .08), overall re-intervention rates (12% vs 24%; P = .26), modified Rankin scale >2 on last follow-up (17.4% vs 32%; P = .24), as well as mortality (0% vs 12%; P = .09). Radiographic improvement at last follow-up was significantly higher in the open surgery cohort (73.9% vs 95.6%; P = .04). However, there was a trend for lengthier last follow-up for the historical cohort (72 vs 104 d; P = .07). CONCLUSION: There was a trend for lower recurrence and mortality rates in the embolization era cohort. There were significantly higher radiological improvement rates on last follow-up in the surgical only cohort era. There were no significant differences in complications and clinical improvement.
Wright, James M, Christina Gerges, Berje Shammassian, Collin M Labak, Eric Z Herring, Benjamin Miller, Ayham Alkhachroum, et al. (2025) 2021. “Prone Position Ventilation in Neurologically Ill Patients: A Systematic Reviewand Proposed Protocol.”. Critical Care Medicine 49 (3): e269—e278. https://doi.org/10.1097/CCM.0000000000004820.
OBJECTIVES: Prone positioning has been shown to be a beneficial adjunctive supportive measure for patients who develop acute respiratory distress syndrome. Studies have excluded patients with reduced intracranial compliance, whereby patients with concomitant neurologic diagnoses and acute respiratory distress syndrome have no defined treatment algorithm or recommendations for management. In this study, we aim to determine the safety and feasibility of prone positioning in the neurologically ill patients. DESIGN AND SETTING: A systematic review of the literature, performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses 2009 guidelines, yielded 10 articles for analysis. Using consensus from these articles, in combination with review of multi-institutional proning protocols for patients with nonneurologic conditions, a proning protocol for patients with intracranial pathology and concomitant acute respiratory distress syndrome was developed. MEASUREMENTS AND MAIN RESULTS: Among 10 studies included in the final analysis, we found that prone positioning is safe and feasible in the neurologically ill patients with acute respiratory distress syndrome. Increased intracranial pressure and compromised cerebral perfusion pressure may occur with prone positioning. We propose a prone positioning protocol for the neurologically ill patients who require frequent neurologic examinations and intracranial monitoring. CONCLUSIONS: Although elevations in intracranial pressure and reductions in cerebral perfusion pressure do occur during proning, they may not occur to a degree that would warrant exclusion of prone ventilation as a treatment modality for patients with acute respiratory distress syndrome and concomitant neurologic diagnoses. In cases where intracranial pressure, cerebral perfusion pressure, and brain tissue oxygenation can be monitored, prone position ventilation should be considered a safe and viable therapy.
Feng, Rui, Samantha E Hoffman, Katherine Wagner, Jamie S Ullman, Martina Stippler, and Isabelle M Germano. (2025) 2021. “Women Neurosurgeons in Academic and Other Leadership Positions in the UnitedStates.”. World Neurosurgery 147: 80-88. https://doi.org/10.1016/j.wneu.2020.12.069.
OBJECTIVE: To provide the status of women neurosurgeons (WNS) in academic faculty and/or leadership positions in neurosurgery in the United States. METHODS: Neurosurgery academic programs were defined as having an Accreditation Council for Graduate Medical Education (ACGME) neurosurgery residency program (NSRP). Using a Google search, gender, academic rank, postgraduate degrees, academic and clinical titles, and subspecialty were recorded for each neurosurgery faculty. Officer gender was recorded for the top 7 neurosurgery U.S. organizations, 7 subspecialty sections, and 50 state neurosurgical societies. RESULTS: WNS were faculty at 77% (89/115) of ACGME NSRPs and constituted 10% of the workforce (186/1773). WNS residents were in 92% of ACGME NSRPs and constituted 19% of the workforce (293/1515). Two NSRPs (8%) had neither WNS faculty nor WNS residents. Of NSRPs without WNS faculty, 52% (13/25) had a faculty size >10. WNS accounted for 3% of NSRP chair positions. Academic rank of WNS faculty was lower than academic rank of men neurosurgeons faculty (P 0.05). WNS faculty had a higher number of postgraduate degrees (P 0.05). Pediatrics was the most common subspecialty (30%) among WNS. Over time, WNS held 1% of the leadership positions within the top 7 U.S. neurosurgery organizations and 7% within the 7 subspecialty sections. Over the past 20 years, 28% (14/50) of U.S. state neurosurgical societies had WNS serve as president. CONCLUSIONS: In 2020, the gender gap for U.S. WNS faculty and residents still exists. By providing informed benchmarks, our study might help neurosurgery organizations, medical school leadership, hiring committees, editors, and conference speakers to plan their next steps.
Uhlmann, Erik J, Rosalia Rabinovsky, Hemant Varma, Rachid El Fatimy, Ekkehard M Kasper, Justin M Moore, Rafael A Vega, et al. (2025) 2021. “Tumor-Derived Cell Culture Model for the Investigation of Meningioma Biology.”. Journal of Neuropathology and Experimental Neurology 80 (12): 1117-24. https://doi.org/10.1093/jnen/nlab111.
Meningioma is the most common primary central nervous system tumor. Although mostly nonmalignant, meningioma can cause serious complications by mass effect and vasogenic edema. While surgery and radiation improve outcomes, not all cases can be treated due to eloquent location. Presently no medical treatment is available to slow meningioma growth owing to incomplete understanding of the underlying pathology, which in turn is due to the lack of high-fidelity tissue culture and animal models. We propose a simple and rapid method for the establishment of meningioma tumor-derived primary cultures. These cells can be maintained in culture for a limited time in serum-free media as spheres and form adherent cultures in the presence of 4% fetal calf serum. Many of the tissue samples show expression of the lineage marker PDG2S, which is typically retained in matched cultured cells, suggesting the presence of cells of arachnoid origin. Furthermore, nonarachnoid cells including vascular endothelial cells are also present in the cultures in addition to arachnoid cells, potentially providing a more accurate tumor cell microenvironment, and thus making the model more relevant for meningioma research and high-throughput drug screening.
Mackel, Charles E, Emmalin B Nelton, Ren\ ee M Reynolds, Christopher Fox, Alejandro M Spiotta, and Martina Stippler. (2025) 2021. “A Scoping Review of Burnout in Neurosurgery.”. Neurosurgery 88 (5): 942-54. https://doi.org/10.1093/neuros/nyaa564.
BACKGROUND: Burnout is a negative workplace syndrome of emotional exhaustion, cynicism, and perceived professional inefficacy that risks the patient-provider relationship, patient care, and physician well-being. OBJECTIVE: To assimilate the neurosurgical burnout literature in order to classify burnout among domestic and international neurosurgeons and trainees, identify contributory factors, and appraise the impact of wellness programs. METHODS: A scoping review identified the available literature, which was reviewed for key factors related to burnout among neurosurgeons. Two researchers queried PubMed, Embase, Google Scholar, Cochrane, and Web of Science for articles on burnout in neurosurgery and reduced 1610 results to 32 articles. RESULTS: A total of 32 studies examined burnout in neurosurgery. A total of 26 studies examined prevalence and 8 studies detailed impact of wellness programs. All were published after 2011. Burnout prevalence was measured mostly through the Maslach Burnout Inventory (n = 21). In 4 studies, participants defined their own understanding of "burnout." Domestically, burnout prevalence was 11.2% to 67% among residents and 15% to 57% among attendings. Among trainees, poor operative experience, poor faculty relationships, and social stressors were burnout risks but not age, sex, or marital status. Among attendings, the literature identified financial or legal concerns, lack of intellectual stimulation, and poor work-life balance as risks. The impact of wellness programs on trainees is unclear but group exercises may offer the most benefit. CONCLUSION: Noticeable methodological differences in studies on trainee and attending burnout contribute to a wide range of neurosurgery burnout estimates and yield significant knowledge gaps. Environment may have greater impact on trainee burnout than demographics. Wellness programs should emphasize solidarity.

2020

Maragkos, Georgios A, Emmalin B Nelton, Sven Richter, and Martina Stippler. (2025) 2020. “Low Risk of Traumatic Intracranial Hematoma Expansion With Factor Xa Inhibitorswithout Andexanet Reversal.”. World Neurosurgery 142: e95—e100. https://doi.org/10.1016/j.wneu.2020.06.069.
BACKGROUND: Andexanet alfa, a novel anticoagulation reversal agent for factor Xa inhibitors, was recently approved. Traumatic intracranial hemorrhage presents a prime target for this drug. The Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors study established the efficacy of andexanet alfa in reversing factor Xa inhibitors. However, the association between anticoagulation reversal and traumatic intracranial hemorrhage progression is not well understood. The objective of this study was to determine progression rates of patients with traumatic intracranial hemorrhage on factor Xa inhibitors prior to hospitalization who were managed without the use of andexanet alfa. METHODS: A retrospective cohort study was performed between 2016 and 2019 at a single institution. An institutional traumatic brain injury (TBI) registry was queried. Patients with recorded use of apixaban or rivaroxaban 18 hours before injury were included. The primary study outcome was 35% increase in hemorrhage volume or thickness on repeated head computed tomography (CT) scans. RESULTS: We identified 25 patients meeting the inclusion criteria. Two patients were excluded because of a lack of necessary CT data. Twelve patients (52%) were receiving apixaban, and 11 were (48%) on rivaroxaban. On admission CT scan, 14 patients had subdural hematoma, 6 had traumatic intraparenchymal hemorrhage, and 3 had subarachnoid hemorrhage. Anticoagulation reversal was attempted in 17 patients (74%), primarily using 4-factor prothrombin complex concentrate. Twenty patients (87%) were adjudicated as having excellent or good hemostasis on repeat imaging. CONCLUSIONS: Our results indicate that patients on factor Xa inhibitors with complicated mild TBI have a similar intracranial hemorrhage progression rate to patients who are not anticoagulated or anticoagulated with a reversible agent. The hemostatic outcomes in our cohort were similar to those reported after andexanet alfa administration.
Atesok, Kivanc, Martina Stippler, Brendan M Striano, Grace Xiong, Matthew Lindsey, Elysia Cappellucci, Alexandra Psilos, et al. (2025) 2020. “Bisphosphonates and Parathyroid Hormone Analogs for Improving Bone Quality Inspinal Fusion: State of Evidence.”. Orthopedic Reviews 12 (2): 8590. https://doi.org/10.4081/or.2020.8590.
Spinal fusion is among the most commonly performed surgical procedures for elderly patients with spinal disorders - including degenerative disc disease with spondylolisthesis, deformities, and trauma. With the large increase in the aging population and the prevalence of osteoporosis, the number of elderly osteoporotic patients needing spinal fusion has risen dramatically. Due to reduced bone quality, postoperative complications such as implant failures, fractures, post-junctional kyphosis, and pseudarthrosis are more commonly seen after spinal fusion in osteoporotic patients. Therefore, pharmacologic treatment strategies to improve bone quality are commonly pursued in osteoporotic cases before conducting spinal fusions. The two most commonly used pharmacotherapeutics are bisphosphonates and parathyroid hormone (PTH) analogs. Evidence indicates that using bisphosphonates and PTH analogs, alone or in combination, in osteoporotic patients undergoing spinal fusion, decreases complication rates and improves clinical outcomes. Further studies are needed to develop guidelines for the administration of bisphosphonates and PTH analogs in osteoporotic spinal fusion patients in terms of treatment duration, potential benefits of sequential use, and the selection of either therapeutic agents based on patient characteristics.
Corley, Jacquelyn, Eliana Kim, Chris Ann Philips, Martina Stippler, Ann M Parr, Jennifer Sweet, and Gail Rosseau. (2025) 2020. “One Hundred Years of Neurosurgery: Contributions of American Women.”. Journal of Neurosurgery 134 (2): 337-42. https://doi.org/10.3171/2019.12.JNS192878.
The end of the first 100 years of any endeavor is an appropriate time to look back and peer forward. As neurosurgery celebrates its 1st century as a specialty, the increasing role of women neurosurgeons is a major theme. This article documents the early women pioneers in neurosurgery. The contributions of these trailblazers to the origins, academics, and professional organizations of neurosurgery are highlighted. The formation of Women in Neurosurgery in 1989 is described, as is the important role this organization has played in introducing and promoting talented women in the profession. Contributions of women neurosurgeons to academic medicine and society as a whole are briefly highlighted. Contemporary efforts and initiatives indicate future directions in which women may lead neurosurgery in its 2nd century.
Atesok, Kivanc, Alexander Vaccaro, Martina Stippler, Brendan M Striano, Michael Carr, Michael Heffernan, Steven Theiss, and Efstathios Papavassiliou. (2025) 2020. “Fate of Hardware in Spinal Infections.”. Surgical Infections 21 (5): 404-10. https://doi.org/10.1089/sur.2019.206.
Background: Removal of hardware with irrigation and debridement in patients with surgical site infections (SSIs) is performed commonly. However, the removal of hardware from patients with SSIs after spinal procedures is controversial. Moreover, primary spinal infections such as spondylodiscitis may require instrumentation along with surgical debridement. The purpose of this article was to evaluate critically and summarize the available evidence related to retention of hardware in patients with deep SSIs, and the use of instrumentation in surgical treatment of primary spinal infections. Methods: A literature search utilizing PubMed database was performed. Studies reporting the management of deep SSIs after instrumented spinal procedures, and of primary spinal infections using instrumentation published in peer-reviewed journals were included. Identified publications were evaluated for relevance, and data were extracted from the studies deemed relevant. Results: Because SSIs occur typically during the early post-operative period before stable bony fusion has been achieved, the removal of instrumentation may be associated with instability of the spinal column, pseudarthrosis, progressive deformity, pain, loss of function, and deterioration in the activities of daily living (ADL). Hence, early SSIs after spinal instrumentation are usually treated without removal of hardware. Moreover, primary spinal infections such as spondylodiscitis may require surgical debridement and instrumentation in cases with associated instability. Conclusions: Retaining or using instrumentation in patients with SSIs after spinal procedures or in patients with primary spinal infections, respectively, are commonly practiced in the field of spine surgery. Further evidence is required for the development of definitive algorithms to guide spine surgeons in decision making regarding the fate of instrumentation in the treatment of spinal infections.

2019

Motiei-Langroudi, Rouzbeh, Ajith J Thomas, Luis Ascanio, Abdulrahman Alturki, Efstathios Papavassiliou, Ekkehard M Kasper, Jeffrey Arle, Ronnie L Alterman, Christopher S Ogilvy, and Martina Stippler. (2025) 2019. “Factors Predicting the Need for Surgery of the Opposite Side After UnilateralEvacuation of Bilateral Chronic Subdural Hematomas.”. Neurosurgery 85 (5): 648-55. https://doi.org/10.1093/neuros/nyy432.
BACKGROUND: Patients with bilateral chronic subdural hematoma (bCSDH) undergo unilateral evacuation for the large or symptomatic side because the contralateral hematoma is either small or asymptomatic. However, the contralateral hematoma may subsequently grow and require evacuation. OBJECTIVE: To characterize factors that predict contralateral hematoma growth and need for evacuation. METHODS: A retrospective study on 128 surgically treated bCSDHs. RESULTS: Fifty-one and 77 were bilaterally and unilaterally evacuated, respectively. Glasgow Coma Scale was lower and midline shift was higher in those evacuated unilaterally compared to those evacuated bilaterally. Hematoma size was a significant determinant of decision for unilateral vs bilateral evacuation. The contralateral side needed evacuation at a later stage in 7 cases (9.1%). There was no significant difference in terms of reoperation rate between those evacuated unilaterally and bilaterally. Greater contralateral hematoma thickness on the first postoperative day computed tomography (CT) and more postoperative midline shift reversal had higher rates of operation in the opposite side. There was no difference between the daily pace of hematoma decrease in the operated and nonoperated sides (0.7% decrease per day vs 0.9% for the operated and nonoperated sides, respectively). CONCLUSION: Results of this study show that most bCSDHs evacuated unilaterally do not experience growth in the nonoperated side and unilateral evacuation results in hematoma resolution for both sides in most cases. Hematoma thickness on the opposite side on the first postoperative day CT and amount of midline shift reversal after surgery are the most important factors predicting the need for surgery on the opposite side.