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Open access

Jorge A. Roa, Alexander J. Schupper, Kurt Yaeger, and Constantinos G. Hadjipanayis

BACKGROUND

The supracerebellar infratentorial approach provides wide flexibility as a far-reaching corridor to the pineal region, posterior third ventricle, posterior medial temporal lobe, posterolateral mesencephalon, quadrigeminal cistern, and thalamus. Traditionally, the patient is placed in the sitting position, allowing gravity retraction on the cerebellum to widen the supracerebellar operative corridor beneath the tentorium. What this approach gains in anatomical orientation it lacks in surgeon ergonomics, as the sitting position presents technical challenges, forces the surgeon to adopt to an uncomfortable posture while performing the microsurgical dissection/tumor resection under the microscope, and is also associated with an increased risk of venous air embolism.

OBSERVATIONS

In this article, the authors present the use of the three-dimensional (3D) exoscope with a standard prone Concorde position as an alternative for the treatment of lesions requiring a supracerebellar infratentorial approach for lesions in the pineal region, posterior third ventricle, and the superior surface of the cerebellar vermis. The authors present four illustrative cases (one pineal cyst, one ependymoma, and two cerebellar metastases) in which this approach provided excellent intraoperative visualization and resulted in good postoperative results. A step-by-step description of our surgical technique is reviewed in detail.

LESSONS

The use of the 3D exoscope with the patient in the prone Concorde position is an effective and ergonomically favorable alternative to the traditional sitting position for the treatment of lesions requiring a supracerebellar infratentorial approach. This technique allows improved visualization of deep structures, with a possible decreased risk of potential complications.

Open access

Alexander J. Schupper, Jorge A. Roa, and Constantinos G. Hadjipanayis

Maximal safe resection is the primary goal of glioma surgery. By incorporating improved intraoperative visualization with the 3D exoscope combined with 5-ALA fluorescence, in addition to neuronavigation and diffusion tensor imaging (DTI) fiber tracking, the safety of resection of tumors in eloquent brain regions can be maximized. This video highlights some of the various intraoperative adjuncts used in brain tumor surgery for high-grade glioma.

In this case, the authors highlight the resection of a left posterior temporal lobe high-grade glioma in a 33-year-old patient, who initially presented with seizures, word-finding difficulty, and right-sided weakness. They demonstrate the multiple surgical adjuncts used both before and during surgical resection, and how multiple adjuncts can be effectively orchestrated to make surgery in eloquent brain areas safer for patients. Patient consent was obtained for publication.

The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21174

Free access

Kurt A. Yaeger, Alexander J. Schupper, Jeffrey T. Gilligan, and Isabelle M. Germano

OBJECTIVE

Neurosurgery is a highly competitive residency field with a match rate lower than that of other specialties. The aim of this study was to analyze trends associated with the residency match process from the applicants’ and program directors’ perspectives.

METHODS

Between 2010 and 2020, the National Residency Matching Program (NRMP) Applicant and Program Director Surveys, the NRMP Charting Outcomes reports, and the Accreditation Council for Graduate Medical Education (ACGME) Data Resource Books were analyzed to identify the number of applicants interviewed and ranked in US programs, the applicants’ ranking preferences, the program directors’ preferential factors in offering interviews, and rank list order. Applicants were divided between US senior medical students and independent applicants. Each cohort was dichotomized for matched and unmatched applicants.

RESULTS

Over the study period, 2935 applicants applied to neurosurgery residency, including 2135 US senior medical students and 800 independent applicants, with an overall match rate of 65%. Overall, matched applicants had a significantly higher number of publications (p < 0.05). Among US senior medical student applicants, the application-to-interview ratio more than doubled over the study period, yet the number of interview invitations received, interviews accepted, and programs ranked remained unchanged. In the US senior medical student cohort, the number of submitted applications, interview invitations, accepted interviews, and programs ranked did not significantly differ between matched and unmatched applicants. In both cohorts, applicants shifted ranking factors from a more academic focus in early years to more well-being in later years. Letters of recommendation and board scores were key factors for program directors while screening applicants for interviews and ranking.

CONCLUSIONS

Neurosurgery residency continues to be a highly competitive field in medicine, with match rates of 65%. Recently, applicants have placed greater importance on ranking programs that value residents’ well-being, as opposed to strictly academic factors. A data-driven understanding of factors important to applicants and program directors during the match process has the potential to improve resident candidate recruitment and overall resident-program fit, thereby improving well-being during residency, reducing the attrition rate, and overall enhancing the diversity of the neurosurgery resident workforce.

Full access

Cecilia L. Dalle Ore, Robert C. Rennert, Alexander J. Schupper, Brandon C. Gabel, David Gonda, Bradley Peterson, Lawrence F. Marshall, Michael Levy, and Hal S. Meltzer

OBJECTIVE

Pediatric traumatic subarachnoid hemorrhage (tSAH) often results in intensive care unit (ICU) admission, the performance of additional diagnostic studies, and ICU-level therapeutic interventions to identify and prevent episodes of neuroworsening.

METHODS

Data prospectively collected in an institutionally specific trauma registry between 2006 and 2015 were supplemented with a retrospective chart review of children admitted with isolated traumatic subarachnoid hemorrhage (tSAH) and an admission Glasgow Coma Scale (GCS) score of 13–15. Risk of blunt cerebrovascular injury (BCVI) was calculated using the BCVI clinical prediction score.

RESULTS

Three hundred seventeen of 10,395 pediatric trauma patients were admitted with tSAH. Of the 317 patients with tSAH, 51 children (16%, 23 female, 28 male) were identified with isolated tSAH without midline shift on neuroimaging and a GCS score of 13–15 at presentation. The median patient age was 4 years (range 18 days to 15 years). Seven had modified Fisher grade 3 tSAH; the remainder had grade 1 tSAH. Twenty-six patients (51%) had associated skull fractures; 4 involved the petrous temporal bone and 1 the carotid canal. Thirty-nine (76.5%) were admitted to the ICU and 12 (23.5%) to the surgical ward. Four had an elevated BCVI score. Eight underwent CT angiography; no vascular injuries were identified. Nine patients received an imaging-associated general anesthetic. Five received hypertonic saline in the ICU. Patients with a modified Fisher grade 1 tSAH had a significantly shorter ICU stay as compared to modified Fisher grade 3 tSAH (1.1 vs 2.5 days, p = 0.029). Neuroworsening was not observed in any child.

CONCLUSIONS

Children with isolated tSAH without midline shift and a GCS score of 13–15 at presentation appear to have minimal risk of neuroworsening despite the findings in some children of skull fractures, elevated modified Fisher grade, and elevated BCVI score. In this subgroup of children with tSAH, routine ICU-level care and additional diagnostic imaging may not be necessary for all patients. Children with modified Fisher grade 1 tSAH may be particularly unlikely to require ICU-level admission. Benefits to identifying a subgroup of children at low risk of neuroworsening include improvement in healthcare efficiency as well as decreased utilization of unnecessary and potentially morbid interventions, including exposure to ionizing radiation and general anesthesia.

Free access

Zachary Spiera, Theodore Hannah, Adam Li, Nickolas Dreher, Naoum Fares Marayati, Muhammad Ali, Dhruv S. Shankar, John Durbin, Alexander J. Schupper, Alex Gometz, Mark Lovell, and Tanvir Choudhri

OBJECTIVE

Given concerns about the potential long-term effects of concussion in young athletes, concussion prevention has become a major focus for amateur sports leagues. Athletes have been known to frequently use anti-inflammatory medications to manage injuries, expedite return to play, and treat concussion symptoms. However, the effects of baseline nonsteroidal anti-inflammatory drug (NSAID) use on the susceptibility to head injury and concussion remain unclear. This study aims to assess the effects of preinjury NSAID use on concussion incidence, severity, and recovery in young athletes.

METHODS

Data from 25,815 ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) tests were obtained through a research agreement with ImPACT Applications Inc. Subjects ranged in age from 12 to 22 years old. Those who reported NSAID use at baseline were assigned to one (anti-inflammatory [AI]) cohort, whereas all others were assigned to the control (CT) cohort. Differences in head trauma and concussion incidence, severity, and recovery were assessed using chi-square tests, unpaired t-tests, and Kaplan-Meier plots.

RESULTS

The CT cohort comprised a higher percentage (p < 0.0001) of males (66.30%) than the AI cohort (44.16%) and had a significantly greater portion of athletes who played football (p = 0.004). However, no statistically significant differences were found between the two cohorts in terms of the incidence of head trauma (CT = 0.489, AI = 0.500, p = 0.9219), concussion incidence (CT = 0.175, AI = 0.169, p = 0.7201), injury severity, or median concussion recovery time (CT = 8, AI = 8, p = 0.6416). In a multivariable analysis controlling for baseline differences between the cohorts, no association was found between NSAID use and concussion incidence or severity.

CONCLUSIONS

In this analysis, the authors found no evidence that preinjury use of NSAIDs affects concussion risk in adolescent athletes. They also found no indication that preinjury NSAID use affects the severity of initial injury presentation or concussion recovery.

Restricted access

Theodore C. Hannah, Roshini Kalagara, Muhammad Ali, Alexander J. Schupper, Adam Y. Li, Zachary Spiera, Naoum Fares Marayati, Addison Quinones, Zerubabbel K. Asfaw, Vikram Vasan, Eugene I. Hrabarchuk, Lily McCarthy, Alex Gometz, Mark Lovell, and Tanvir Choudhri

OBJECTIVE

Concussion incidence is known to be highest in children and adolescents; however, there is conflicting evidence about the effect of age on concussion risk and recovery within the adolescent age range. The heterogeneity of results may be partially due to the use of age groupings based on convenience, making comparisons across studies difficult. This study evaluated the independent effect of age on concussion incidence, severity, and recovery in student-athletes aged 12–18 years using cluster analysis to define groupings.

METHODS

Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) scores of 11,403 baseline tests and 4922 postinjury tests were used to calculate the incidence rates for adolescent student-athletes grouped into 3 age bands (12–13, 14–15, and 16–18 years of age) on the basis of clustering analysis. The recently created Severity Index was used to compare concussion severity between groups. Follow-up tests for subjects who sustained a concussion were used to evaluate recovery time. The chi-square test and 1-way ANOVA were used to compare differences in demographic characteristics and concussion incidence, severity, and recovery. Multivariable logistic and linear regressions were used to evaluate the independent effects of age on concussion incidence and severity, respectively. Multivariable Cox hazard regression was used to evaluate differences in recovery time. Further analyses were conducted to directly compare findings across studies on the basis of the age groupings used in prior studies.

RESULTS

Multivariable regression analyses demonstrated that the 14- to 15-year-old age group had a significantly higher concussion incidence than both the 12- to 13-year-old (14- to 15-year-old group vs 12- to 13-year-old group, OR 1.57, 95% CI 1.16–2.17, p = 0.005) and 16- to 18-year-old (16- to 18-year-old group vs 14- to 15-year-old group, OR 0.79, 95% CI 0.69–0.91, p = 0.0008) age groups. There was no difference in incidence between the 12- to 13-year-old and 16- to 18-year-old groups (16- to 18-year group vs 12- to 13-year group, OR 1.26, 95% CI 0.93–1.72, p = 0.15). There were also no differences in concussion severity or recovery between any groups.

CONCLUSIONS

This study found that concussion incidence was higher during mid-adolescence than early and late adolescence, suggesting a U-shaped relationship between age and concussion risk over the course of adolescence. Age had no independent effect on concussion severity or recovery in the 12- to 13-, 14- to 15-, and 16- to 18-year-old groups. Further analysis of the various age groups revealed that results may vary significantly with minor changes to groupings, which may explain the divergent results in the current literature on this topic. Thus, caution should be taken when interpreting the results of this and all similar studies, especially when groupings are based on convenience.

Restricted access

Alexander J. Schupper, Rebecca B. Baron, William Cheung, Jessica Rodriguez, Steven N. Kalkanis, Muhammad O. Chohan, Bruce J. Andersen, Roukoz Chamoun, Brian V. Nahed, Brad E. Zacharia, Jerone Kennedy, Hugh D. Moulding, Lloyd Zucker, Michael R. Chicoine, Jeffrey J. Olson, Randy L. Jensen, Jonathan H. Sherman, Xiangnan Zhang, Gabrielle Price, Mary Fowkes, Isabelle M. Germano, Bob S. Carter, Constantinos G. Hadjipanayis, and Raymund L. Yong

OBJECTIVE

Greater extent of resection (EOR) is associated with longer overall survival in patients with high-grade gliomas (HGGs). 5-Aminolevulinic acid (5-ALA) can increase EOR by improving intraoperative visualization of contrast-enhancing tumor during fluorescence-guided surgery (FGS). When administered orally, 5-ALA is converted by glioma cells into protoporphyrin IX (PPIX), which fluoresces under blue 400-nm light. 5-ALA has been available for use in Europe since 2010, but only recently gained FDA approval as an intraoperative imaging agent for HGG tissue. In this first-ever, to the authors’ knowledge, multicenter 5-ALA FGS study conducted in the United States, the primary objectives were the following: 1) assess the diagnostic accuracy of 5-ALA–induced PPIX fluorescence for HGG histopathology across diverse centers and surgeons; and 2) assess the safety profile of 5-ALA FGS, with particular attention to neurological morbidity.

METHODS

This single-arm, multicenter, prospective study included adults aged 18–80 years with Karnofsky Performance Status (KPS) score > 60 and an MRI diagnosis of suspected new or recurrent resectable HGG. Intraoperatively, 3–5 samples per tumor were taken and their fluorescence status was recorded by the surgeon. Specimens were submitted for histopathological analysis. Patients were followed for 6 weeks postoperatively for adverse events, changes in the neurological exam, and KPS score. Multivariate analyses were performed of the outcomes of KPS decline, EOR, and residual enhancing tumor volume to identify predictive patient and intraoperative variables.

RESULTS

Sixty-nine patients underwent 5-ALA FGS, providing 275 tumor samples for analysis. PPIX fluorescence had a sensitivity of 96.5%, specificity of 29.4%, positive predictive value (PPV) for HGG histopathology of 95.4%, and diagnostic accuracy of 92.4%. Drug-related adverse events occurred at a rate of 22%. Serious adverse events due to intraoperative neurological injury, which may have resulted from FGS, occurred at a rate of 4.3%. There were 2 deaths unrelated to FGS. Compared to preoperative KPS scores, postoperative KPS scores were significantly lower at 48 hours and 2 weeks but were not different at 6 weeks postoperatively. Complete resection of enhancing tumor occurred in 51.9% of patients. Smaller preoperative tumor volume and use of intraoperative MRI predicted lower residual tumor volume.

CONCLUSIONS

PPIX fluorescence, as judged by the surgeon, has a high sensitivity and PPV for HGG. 5-ALA was well tolerated in terms of drug-related adverse events, and its application by trained surgeons in FGS for HGGs was not associated with any excess neurological morbidity.

Free access

Michael L. Martini, Sean N. Neifert, William H. Shuman, Emily K. Chapman, Alexander J. Schüpper, Eric K. Oermann, J Mocco, Michael Todd, James C. Torner, Andrew Molyneux, Stephan Mayer, Peter Le Roux, Mervyn D. I. Vergouwen, Gabriel J. E. Rinkel, George K. C. Wong, Peter Kirkpatrick, Audrey Quinn, Daniel Hänggi, Nima Etminan, Walter M. van den Bergh, Blessing N. R. Jaja, Michael Cusimano, Tom A. Schweizer, Jose I. Suarez, Hitoshi Fukuda, Sen Yamagata, Benjamin Lo, Airton Leonardo de Oliveira Manoel, Hieronymus D. Boogaarts, R. Loch Macdonald, and

OBJECTIVE

Rescue therapies have been recommended for patients with angiographic vasospasm (aVSP) and delayed cerebral ischemia (DCI) following subarachnoid hemorrhage (SAH). However, there is little evidence from randomized clinical trials that these therapies are safe and effective. The primary aim of this study was to apply game theory–based methods in explainable machine learning (ML) and propensity score matching to determine if rescue therapy was associated with better 3-month outcomes following post-SAH aVSP and DCI. The authors also sought to use these explainable ML methods to identify patient populations that were more likely to receive rescue therapy and factors associated with better outcomes after rescue therapy.

METHODS

Data for patients with aVSP or DCI after SAH were obtained from 8 clinical trials and 1 observational study in the Subarachnoid Hemorrhage International Trialists repository. Gradient boosting ML models were constructed for each patient to predict the probability of receiving rescue therapy and the 3-month Glasgow Outcome Scale (GOS) score. Favorable outcome was defined as a 3-month GOS score of 4 or 5. Shapley Additive Explanation (SHAP) values were calculated for each patient-derived model to quantify feature importance and interaction effects. Variables with high SHAP importance in predicting rescue therapy administration were used in a propensity score–matched analysis of rescue therapy and 3-month GOS scores.

RESULTS

The authors identified 1532 patients with aVSP or DCI. Predictive, explainable ML models revealed that aneurysm characteristics and neurological complications, but not admission neurological scores, carried the highest relative importance rankings in predicting whether rescue therapy was administered. Younger age and absence of cerebral ischemia/infarction were invariably linked to better rescue outcomes, whereas the other important predictors of outcome varied by rescue type (interventional or noninterventional). In a propensity score–matched analysis guided by SHAP-based variable selection, rescue therapy was associated with higher odds of 3-month GOS scores of 4–5 (OR 1.63, 95% CI 1.22–2.17).

CONCLUSIONS

Rescue therapy may increase the odds of good outcome in patients with aVSP or DCI after SAH. Given the strong association between cerebral ischemia/infarction and poor outcome, trials focusing on preventative or therapeutic interventions in these patients may be most able to demonstrate improvements in clinical outcomes. Insights developed from these models may be helpful for improving patient selection and trial design.