The impact of a night float system on operative experience in neurosurgery residency

OBJECTIVE

Since the Accreditation Council for Graduate Medical Education (ACGME) implemented duty-hour restrictions in 2003, many residency programs have adopted a night float system to comply with time constraints. However, some surgical subspecialities have been concerned that use of a night float system deprives residents of operative experience. In this study, the authors describe their training program's transition to a night float system and its impact on resident operative experience.

METHODS

The authors conducted a single-program study of resident surgical case volume before and after implementing the night float system at 3 of their 5 hospitals from 2014 to 2020. The authors obtained surgical case numbers from the ACGME case log database.

RESULTS

Junior residents received a concentrated educational experience, whereas senior residents saw a significant decrease from 112 calls/year to 17. Logged cases significantly increased after implementation of the night float system (8846 vs 10,547, p = 0.04), whereas cases at non-night float hospitals remained the same. This increase was concurrent with an increase in hospital cases. This difference was mainly driven by senior resident cases (p = 0.010), as junior and chief residents did not show significant differences in logged cases (p > 0.40). Lead resident cases increased significantly after implementation of the night float system (6852 vs 8860, p = 0.04). When normalized for increased hospital cases, resident case increases were not statistically significant.

CONCLUSIONS

Transitioning to a night float call system at the authors' institution increased overall resident operative cases, particularly for lead resident surgeons. Based on the results of this study, the authors recommend the use of a night float call system to consolidate night calls, which increases junior resident-level educational opportunities and senior resident cases.

Recurrent liponeurocytoma: A case report and systematic review of the literature

Background:

Liponeurocytomas are rare neurocytic neoplasms that most often arise in the posterior fossa and affect individuals in the third and fifth decades of life. Most reported cases of this unique tumor in the literature have described a favorable clinical prognosis without recurrence. However, increasing reports of recurrent cases prompted the World Health Organization, in 2016, to recategorize the tumor from Grade I to the less favorable Grade II classification. We conducted a systematic review to identify recurrent cases of this unique tumor and to summarize differences between the primary and recurrent cases of liponeurocytoma.

Methods:

A systematic review exploring recurrent liponeurocytoma cases was conducted by searching the PubMed, Google Scholar, and Scopus databases for articles in English. Abstracts from articles were read and selected for full-text review according to a priori criteria. Relevant full-text articles were analyzed for symptoms, imaging, location, histological, pathological, treatment, and recurrence-free time between the primary and recurrent cases.

Results:

Of 4392 articles, 15 articles accounting for 18 patients were included (level of evidence: IV) in the study. Recurrence-free time decreased from an average of 82 months between the primary tumor resection to first recurrence to 31.3 months between the first and second recurrence. Recurrent tumors demonstrated increased pleomorphic neural cells, necrosis, vascular proliferation, and MIB-1 index when compared to the primary tumor. Several cases also demonstrated decreased lipidizing components when compared to the primary tumor, further indicating increased dedifferentiation. The primary treatment for this tumor was surgical resection with occasional adjunctive radiotherapy.

Conclusion:

Recurrent cases of liponeurocytoma have features of increased malignant proliferation compared to the primary cases. The standard treatment for these primary and recurrent tumors is gross total resection. The role of adjunctive radiotherapy remains a matter of debate.

Reconstructive Outcomes of Multilayered Closure of Large Skull Base Dural Defects Following Open Anterior Craniofacial Resection

Introduction Standardized reconstruction protocols for large open anterior skull base defects with dural resection are not well described. Here we report the outcomes and technique of a multilayered reconstructive algorithm utilizing local tissue, dural graft matrix, and microvascular free tissue transfer (MVFTT) for reconstruction of these deformities.

Design This study is a retrospective review.

Results Eleven patients (82% males) met inclusion criteria, with five (45%) having concurrent orbital exenteration and eight (73%) requiring maxillectomy. All patients required dural resection with or without intracranial tumor resection, with the average dural defect being 36.0 ± 25.9 cm2. Dural graft matrices and pericranial flaps were used for primary reconstruction of the dural defects, which were then reinforced with free fascia or muscle overlay by means of MVFTT. Eight (73%) patients underwent anterolateral thigh MVFTT, with the radial forearm, fibula, and vastus lateralis comprising the remainder. Average total surgical time of tumor resection and reconstruction was 14.9 ± 3.8 hours, with median length of hospitalization being 10 days (IQR: 9.5, 14). Continuous cerebrospinal fluid drainage through a lumber drain was utilized in 10 (91%) patients perioperatively, with an average length of indwelling drain of 5 days. Postoperative complications occurred in two (18%) patients who developed asymptomatic pneumocephalus that resolved with high-flow oxygen therapy.

Conclusion A standardized multilayered closure technique of dural graft matrix, pericranial flap, and MVFTT overlay in the reconstruction of large open anterior craniofacial dural defects can assist the reconstructive team in approaching these complex deformities and may help prevent postoperative complications.

Predictors of postoperative seizure outcome in supratentorial meningioma

OBJECTIVE

Meningiomas are the most common primary intracranial tumor. Seizures are common sequelae of meningioma development. Meningioma patients with seizures can be effectively treated with resection, with reports of seizure freedom of 60%-90%. Still, many patients manifest persistent epilepsy. Determining factors associated with worsened seizure outcomes remains critical in improving the quality of life for these patients. The authors sought to identify clinical, radiological, and histological factors associated with worse seizure outcomes in patients with supratentorial meningioma and preoperative seizures.

METHODS

The authors retrospectively reviewed the charts of 384 patients who underwent meningioma resection from 2008 to 2020. The charts of patients with a documented history of preoperative seizures were further reviewed for clinical, radiological, operative, perioperative, histological, and postoperative factors associated with seizures. Engel class at last follow-up was retrospectively assigned by the authors and further grouped into favorable (class I) and worse (class II-IV) outcomes. Factors were subsequently compared by group using comparative statistics. Univariable and multivariable regression models were utilized to identify independent predictors of worse seizure outcome.

RESULTS

Fifty-nine patients (15.4%) were found to have preoperative seizures, of whom 57 had sufficient postoperative data to determine Engel class outcome. Forty-two patients (74%) had Engel class I outcomes. The median follow-up was 17 months. Distinct margins on preoperative imaging (p = 0.012), Simpson grade I resection (p = 0.004), postresection ischemia (p = 0.019), WHO grade (p = 0.019), and recurrent disease (p = 0.015) were found to be the strongest predictors of Engel class outcome in univariable logistic regression. MIB-1 index (p = 0.001) and residual volume (p = 0.014) at last follow-up were found to be the strongest predictors of Engel class outcome in univariable generalized linear regression. Postresection ischemia (p = 0.012), WHO grade (p = 0.022), recurrent disease (p = 0.038), and MIB-1 index (p = 0.002) were found to be the strongest independent predictors of Engel class outcomes in multivariable analysis.

CONCLUSIONS

Postresection ischemia, higher WHO grade, elevated MIB-1 index, and disease recurrence independently predict postresection seizure persistence in patients with supratentorial meningioma. Further understanding of the etiology of these markers may aid in elucidation of this complex disease process and guide management to prevent worse outcomes.

Review of Current Principles of the Diagnosis and Management of Brain Metastases

Brain metastases are the most common intracranial tumors and are increasing in incidence as overall cancer survival improves. Diagnosis of brain metastases involves both clinical examination and magnetic resonance imaging. Treatment may involve a combination of surgery, radiotherapy, and systemic medical therapy depending on the patient’s neurologic status, performance status, and overall oncologic burden. Advances in these domains have substantially impacted the management of brain metastases and improved performance status and survival for some patients. Indications for surgery have expanded with improved patient selection, imaging, and intraoperative monitoring. Robust evidence supports the use of whole brain radiotherapy and stereotactic radiosurgery, for both standalone and adjuvant indications, in almost all patients. Lastly, while systemic medical therapy has historically provided little benefit, modern immunotherapeutic agents have demonstrated promise. Current investigation seeks to determine the utility of neoadjuvant radiotherapy and laser interstitial thermal therapy, which have shown benefit in limited studies to date. This article provides a review of the epidemiology, pathology, diagnosis, and treatment of brain metastases and the corresponding supporting evidence.

Myeloid sarcoma of the skull base: A case report and systematic literature review

Background:

Myeloid sarcoma (MS), or chloroma, is a rare extramedullary malignant tumor that consists of undifferentiated granulocytic cells, and it is most commonly associated with acute myeloid leukemia (AML). Intracranial MS accounts for 0.4% of MS cases, and involvement of the skull base and visual dysfunction is rarely reported. However, the optimal treatment and response to treatment of skull base MS in the presence of visual symptoms is unknown.

Case Description:

A 30-year-old male with a history of AML presented with rapidly progressive vision loss and a sellar and parasellar mass with bilateral cavernous sinus and optic nerve encasement. The patient underwent endoscopic endonasal transsphenoidal biopsy revealing intracranial MS. He was treated postoperatively with high-dose intravenous and intrathecal cytarabine and had complete restoration of his vision by postoperative day 11. A systematic review of the literature identified six cases of skull base MS, five of whom presenting with visual symptoms. All patients underwent systemic chemotherapy with cytarabine and/or cyclophosphamide, with infrequent use of intrathecal chemotherapy or radiation. Those with reported visual outcomes were diagnosed 4 months or longer after symptom onset and demonstrated no visual improvement with treatment.

Conclusion:

Skull base MS is a rare disease entity with a high prevalence of visual dysfunction. Our patient’s complete disappearance of intracranial disease and resolution of visual symptoms with systemic and intrathecal chemotherapy highlight the importance of timely diagnosis and appropriate treatment without a need for direct surgical decompression.

Native pulmonary valve endocarditis requiring pulmonary valve replacement in adulthood: a case series

Native pulmonary valve endocarditis is a rare phenomenon as native valve endocarditis tends to typically affect the left sided heart valves. However, the right-sided heart valves can be affected in patients with a history of intravenous drug use, whereby the tricuspid valve is most commonly affected. We present two cases who were diagnosed with native pulmonary valve endocarditis in the absence of congenital heart disease. In the first case, the native pulmonary valve endocarditis was probably a derivative of compounding factors of an enlarged underlying pulmonary artery and staphylococcal bacteraemia. In the second case, a common causal organism of native valve endocarditis following dental treatment and the resultant echocardiography findings was of significant interest. In summary, native pulmonary valve endocarditis is relatively rare complication in the adult population, especially in the absence of congenital heart disease.

Hemorrhagic cavum vergae colloid cyst: A presentation of anterograde amnesia without hydrocephalus

Background:

Colloid cysts characteristically arise from the roof of the third ventricle near the foramen of Monro, causing symptoms from obstructive hydrocephalus. However, atypical locations have been reported with various clinical presentations, growth patterns, and displacement of surrounding anatomic structures.

Case Description:

Here, we describe the interesting case of a patient with a large hemorrhagic cavum vergae colloid cyst presenting with anterograde amnesia soon after starting antiplatelet therapy. The patient did not have hydrocephalus on presentation and his amnesia persisted after complete removal of the hemorrhagic mass through transcallosal interforniceal approach.

Conclusion:

To the best of our knowledge, this is the only reported instance of a colloid cyst presenting with amnesia in the absence of hydrocephalus. Pathophysiology as well as diagnostic and management strategies of hemorrhagic colloid cysts are discussed.

Predicting surgical decision-making in vestibular schwannoma using tree-based machine learning

OBJECTIVE

Vestibular schwannomas (VSs) are the most common neoplasm of the cerebellopontine angle in adults. Though these lesions are generally slow growing, their growth patterns and associated symptoms can be unpredictable, which may complicate the decision to pursue conservative management versus active intervention. Additionally, surgical decision-making can be controversial because of limited high-quality evidence and multiple quality-of-life considerations. Machine learning (ML) is a powerful tool that utilizes data sets to essentialize multidimensional clinical processes. In this study, the authors trained multiple tree-based ML algorithms to predict the decision for active treatment versus MRI surveillance of VS in a single institutional cohort. In doing so, they sought to assess which preoperative variables carried the most weight in driving the decision for intervention and could be used to guide future surgical decision-making through an evidence-based approach.

METHODS

The authors reviewed the records of patients who had undergone evaluation by neurosurgery and otolaryngology with subsequent active treatment (resection or radiation) for unilateral VS in the period from 2009 to 2021, as well as those of patients who had been evaluated for VS and were managed conservatively throughout 2021. Clinical presentation, radiographic data, and management plans were abstracted from each patient record from the time of first evaluation until the last follow-up or surgery. Each encounter with the patient was treated as an instance involving a management decision that depended on demographics, symptoms, and tumor profile. Decision tree and random forest classifiers were trained and tested to predict the decision for treatment versus imaging surveillance on the basis of unseen data using an 80/20 pseudorandom split. Predictor variables were tuned to maximize performance based on lowest Gini impurity indices. Model performance was optimized using fivefold cross-validation.

RESULTS

One hundred twenty-four patients with 198 rendered decisions concerning management were included in the study. In the decision tree analysis, only a maximum tumor dimension threshold of 1.6 cm and progressive symptoms were required to predict the decision for treatment with 85% accuracy. Optimizing maximum dimension thresholds and including age at presentation boosted accuracy to 88%. Random forest analysis (n = 500 trees) predicted the decision for treatment with 80% accuracy. Factors with the highest variable importance based on multiple measures of importance, including mean minimal conditional depth and largest Gini impurity reduction, were maximum tumor dimension, age at presentation, Koos grade, and progressive symptoms at presentation.

CONCLUSIONS

Tree-based ML was used to predict which factors drive the decision for active treatment of VS with 80%–88% accuracy. The most important factors were maximum tumor dimension, age at presentation, Koos grade, and progressive symptoms. These results can assist in surgical decision-making and patient counseling. They also demonstrate the power of ML algorithms in extracting useful insights from limited data sets.

3D Modeling in Virtual Reality for Resection of a Pineal Region Falcotentorial Meningioma

We present a parietal interhemispheric approach to resect a pineal region falcotentorial meningioma. 3D modeling was utilized to visualize and plan the surgical approach in virtual reality. A 78-year-old woman was incidentally found to have a slow-growing falcotentorial meningioma. The tumor was first treated with stereotactic radiosurgery, but the patient had progressive confusion, memory issues, and bilateral temporal field cuts with interval expansion of the tumor and significantly increased peri-tumoral vasogenic edema on MRI. After recommending tumor resection, the patient consented to surgery and underwent resection via a posterior interhemispheric subsplenial approach. Using a 3D model in virtual reality, we discuss the advantages and disadvantages of various classical approaches to the pineal region for resection of this tumor.^1,2,3 Falcotentorial meningiomas often displace the deep veins inferiorly, making an interhemispheric approach more favorable.^4,5,6 Pre-operative visualization of critical deep venous structures with the 3D model was a valuable adjunct to MRI for achieving safe resection. We depict key steps of the surgical planning process using virtual reality and demonstrate how simulation can be used to evaluate risks and benefits of different surgical corridors. A small rim of residual tumor adherent to the deep cerebral veins was intentionally left behind in order to minimize risk of morbidity to the patient.⁷ At one month follow-up, the patient's cognition had returned to baseline and her vision had significantly improved. Ultimately, surgical planning using virtual reality promotes both neurosurgical education and patient safety through clear visualization and understanding of different surgical approaches.

Multiple approaches converge on three biological subtypes of meningioma and extract new insights from published studies

One-fifth of meningiomas classified as benign by World Health Organization (WHO) histopathological grading will behave malignantly. To better diagnose these tumors, several groups turned to DNA methylation, whereas we combined RNA-sequencing (RNA-seq) and cytogenetics. Both approaches were more accurate than histopathology in identifying aggressive tumors, but whether they revealed similar tumor types was unclear. We therefore performed unbiased DNA methylation, RNA-seq, and cytogenetic profiling on 110 primary meningiomas WHO grade I and II). Each technique distinguished the same three groups (two benign and one malignant) as our previous molecular classification; integrating these methods into one classifier further improved accuracy. Computational modeling revealed strong correlations between transcription and cytogenetic changes, particularly loss of chromosome 1p, in malignant tumors. Applying our classifier to data from previous studies also resolved certain anomalies entailed by grouping tumors by WHO grade. Accurate classification will therefore elucidate meningioma biology as well as improve diagnosis and prognosis.

Racial and Socioeconomic Disparities in Patients With Meningioma: A Retrospective Cohort Study

BACKGROUND

Meningiomas are the most common intracranial neoplasms. Although genomic analysis has helped elucidate differences in survival, there is evidence that racial disparities may influence outcomes. African Americans have a higher incidence of meningiomas and poorer survival outcomes. The etiology of these disparities remains unclear, but may include a combination of pathophysiology and other factors.

OBJECTIVE

To determine factors that contribute to different clinical outcomes in racial populations.

METHODS

We retrospectively reviewed 305 patients who underwent resection for meningiomas at a single tertiary care facility. We used descriptive statistics and univariate, multivariable, and Kaplan-Meier analyses to study clinical, radiographical, and histopathological differences.

RESULTS

Minority patients were more likely to present through the emergency department than an outpatient clinic (P < .0001). They were more likely to present with more advanced clinical symptoms with lower Karnofsky Performance scores, more frequently had peritumoral edema (P = .0031), and experienced longer postoperative stays in the hospital (P = .0053), and African-American patients had higher hospitalization costs (P = .046) and were more likely to be publicly insured. Extent of resection was an independent predictor of recurrence freedom (P = .039). Presentation in clinic setting trended toward an association with recurrence-free survival (P = .055). We observed no significant difference in gross total resection rates, postoperative recurrence, or recurrence-free survival.

CONCLUSION

Minority patients are more likely to present with severe symptoms, require longer perioperative hospitalization, and generate higher hospitalization costs. This may be due to socioeconomic factors that affect access to health care. Targeting barriers to access, especially to subspecialty care, may facilitate more appropriate and timely diagnosis, thereby improving patient care and outcomes.

Predictors of postoperative seizure outcome in supratentorial meningioma

OBJECTIVE

Meningiomas are the most common primary intracranial tumor. Seizures are common sequelae of meningioma development. Meningioma patients with seizures can be effectively treated with resection, with reports of seizure freedom of 60%-90%. Still, many patients manifest persistent epilepsy. Determining factors associated with worsened seizure outcomes remains critical in improving the quality of life for these patients. The authors sought to identify clinical, radiological, and histological factors associated with worse seizure outcomes in patients with supratentorial meningioma and preoperative seizures.

METHODS

The authors retrospectively reviewed the charts of 384 patients who underwent meningioma resection from 2008 to 2020. The charts of patients with a documented history of preoperative seizures were further reviewed for clinical, radiological, operative, perioperative, histological, and postoperative factors associated with seizures. Engel class at last follow-up was retrospectively assigned by the authors and further grouped into favorable (class I) and worse (class II-IV) outcomes. Factors were subsequently compared by group using comparative statistics. Univariable and multivariable regression models were utilized to identify independent predictors of worse seizure outcome.

RESULTS

Fifty-nine patients (15.4%) were found to have preoperative seizures, of whom 57 had sufficient postoperative data to determine Engel class outcome. Forty-two patients (74%) had Engel class I outcomes. The median follow-up was 17 months. Distinct margins on preoperative imaging (p = 0.012), Simpson grade I resection (p = 0.004), postresection ischemia (p = 0.019), WHO grade (p = 0.019), and recurrent disease (p = 0.015) were found to be the strongest predictors of Engel class outcome in univariable logistic regression. MIB-1 index (p = 0.001) and residual volume (p = 0.014) at last follow-up were found to be the strongest predictors of Engel class outcome in univariable generalized linear regression. Postresection ischemia (p = 0.012), WHO grade (p = 0.022), recurrent disease (p = 0.038), and MIB-1 index (p = 0.002) were found to be the strongest independent predictors of Engel class outcomes in multivariable analysis.

CONCLUSIONS

Postresection ischemia, higher WHO grade, elevated MIB-1 index, and disease recurrence independently predict postresection seizure persistence in patients with supratentorial meningioma. Further understanding of the etiology of these markers may aid in elucidation of this complex disease process and guide management to prevent worse outcomes.

Oscillopsia following orbitotomy for intracranial tumor resection

Background:

Oscillopsia is a visual phenomenon in which an individual perceives that their environment is moving when it is in fact stationary. In this report, we describe two patients with pulsatile oscillopsia following orbitocranial approaches for skull base meningioma resection.

Case Description:

Two patients, both 42-year-old women, underwent orbitocranial approaches for resection of a right sphenoid wing (Patient 1) and left cavernous sinus (Patient 2) meningioma. Patient 1 underwent uncomplicated resection and was discharged home without neurologic or visual complaints; she presented 8 days later with pulsatile oscillopsia. This was managed expectantly, and MRA revealed no evidence of vascular pathology. She has not required intervention as of most recent follow-up. Patient 2 developed trochlear and trigeminal nerve palsies following resection and developed pulsatile oscillopsia 4 months postoperatively. After patching and corrective lens application, the patient’s symptoms had improved by 26 months postoperatively.

Conclusion:

Oscillopsia is a potential complication following skull base tumor resection about which patients should be aware. Patients may improve with conservative management alone, although the literature describes repair of orbital defects for ocular pulsations in traumatic and with some developmental conditions.

Virtual Interviews in Neurosurgery Resident Selection-A Work in Progress

INTRODUCTION

Due to the COVID-19 pandemic, the ACGME recommended all interviews for the 2021 residency application cycle be held virtually. Because this is major shift from neurosurgical interviews in past years, this study aims to evaluate both applicant and interviewer satisfaction of conducting interviews virtually.

METHODS

For faculty, an 11-question online survey was sent to 116 United States neurosurgery training programs. A 14-question online survey was sent to 255 neurosurgery applicants. The resulting data were analyzed qualitatively and quantitatively.

RESULTS

From applicants, 118 responses were received. From faculty, 171 individual responses were received. Thirty-five percent (34.7%) of applicants agreed that they were satisfied with the virtual interview process as a whole. Although 44.5% of faculty disagreed with the statement "I would like to replace in-person interviews with virtual interviews in the future", 57.3% of faculty agreed that they were likely to implement virtual interviews in the future.

CONCLUSIONS

Some things might be better assessed through in-person interviews, but there are clear benefits to virtual interviews. Future iterations of the interview process, incorporating virtual interviews, might help determine how and in which situations virtual interviews can be utilized in future residency application cycles.

IDH mutation status and the development of venous thromboembolism in astrocytoma patients

BACKGROUND

Venous thromboembolism (VTE) is a very common adverse event for astrocytoma patients, but validation of proposed risk biomarkers has been elusive. We examine whether the status of the isocitrate dehydrogenase (IDH) gene is a risk factor for the development of venous thromboembolism (VTE) in astrocytoma patients.

METHODS

We conducted a retrospective chart review of 282 astrocytoma patients enrolled in the PROACTIVE (Prospective Assessment of Correlative Biomarker) study at MD Anderson Cancer Center (MDACC) from 9/1/2000 until 12/31/2013.

RESULTS

We identified 282 astrocytoma patients consisting of 49 IDH mutant astrocytomas and 233 IDH wildtype astrocytomas. Glioblastoma was the initial histopathologic diagnosis in 30 (61.2%) of the IDH mutated astrocytomas compared to 227(97.4%) of the IDH wild type astrocytomas. VTE was identified in 52 (18.4%) of patients. VTE was diagnosed in 7 (14.3%) of the IDH mutated astrocytomas compared to 45(19.3%) of the IDH wild type astrocytoma s (p = 0.4094). Median time to VTE from diagnosis was 2.71 months. Median time to VTE from diagnosis was 2.6 months for IDH mutated astrocytomas compared to 3.06 months for the IDH wild type astrocytomas (p = 0.8663).

CONCLUSIONS

IDH gene status did not appear as a significant risk factor for the development of venous thromboembolism (VTE) in our cohort of astrocytoma patients. Further research into potential biomarkers for VTE may be warranted.

Comparison of Simultaneous Bilateral Internal Carotid Artery (ICA) 3-Dimensional Rotational Venography (3D-RV) versus Separate Bilateral ICA 3D-RV and Postprocessing 3D-3D Fusion

BACKGROUND

Preoperative venogram of the superior sagittal sinus (SSS) is helpful to plan the surgical resection strategy in patients with parasagittal meningiomas invading the SSS.

METHODS

Catheter 3-dimensional rotational venography (3D-RV) allows for SSS patency assessment and detection of alternative venous cortical drainage routes in patients with contraindication for magnet resonance venography. It is unknown if separate bilateral internal carotid artery 3D-RV followed by postprocessing 3D-3D fusion (technique 1) achieves the same imaging results as simultaneous bilateral internal carotid artery 3D-RV without postprocessing fusion (technique 2) needed.

RESULTS

In this report we were able to confirm in 2 patients that both techniques achieve comparable imaging quality with similar amount of contrast use.

CONCLUSIONS

Although technique 2 requires less radiation, technique 1 is favored due to the need for only 1 vessel access site and catheter with reduced risk for access site and ischemic complications.

Re-evaluating Biopsy for Recurrent Glioblastoma: A Position Statement by the Christopher Davidson Forum Investigators

Patients with glioblastoma (GBM) need bold new approaches to their treatment, yet progress has been hindered by a relative inability to dynamically track treatment response, mechanisms of resistance, evolution of targetable mutations, and changes in mutational burden. We are writing on behalf of a multidisciplinary group of academic neuro-oncology professionals who met at the collaborative Christopher Davidson Forum at Washington University in St Louis in the fall of 2019. We propose a dramatic but necessary change to the routine management of patients with GBM to advance the field: to routinely biopsy recurrent GBM at the time of presumed recurrence. Data derived from these samples will identify true recurrence vs treatment effect, avoid treatments with little chance of success, enable clinical trial access, and aid in the scientific advancement of our understanding of GBM.

Off-pump external pericardial patch repair for post-infarct left ventricular free wall rupture: a case series

We describe an off-pump surgical approach to this challenging condition supported by our results from a case series, which would add to existing literature in the management of this life-threatening complication. We identified seven patients who underwent surgical intervention for left ventricular (LV) free wall rupture at our institution. They were all diagnosed to have cardiac tamponade secondary to free wall rupture of the LV in the presence of acute myocardial infarction. The surgical technique comprised of utilizing an external pericardial patch which was secured using surgical biological glues (fibrin-based sealants or gelatin hydrogels). The 30-day mortality, 1-year survival and 2-year survival were 57, 42 and 42%, respectively. Advanced age, female gender and use of cardiopulmonary bypass were characteristics that were not significantly associated with survival. We advocate the use of an off-pump external pericardial patch repair strategy as a ‘bridge to recovery’ in this extremely high-risk group of patients.

Cavernous Malformation Surgery in the United States: Validation of a Novel International Classification of Disease, 10th Edition, Clinical Modification Code Search Algorithm and Volume-Driven Surgical Outcomes

OBJECTIVE

The surgical decision-making process for cavernous malformation (CM) must weigh the risks of surgery against the burden of patient symptoms/hemorrhage and anticipated natural history. Here, we sought to internally validate an International Classification of Disease (ICD)-10 search algorithm for CM surgery to use to analyze a nationwide administrative database.

METHODS

Institutional records were accessed to test the validity of a novel ICD-10 search algorithm for CM surgery. The algorithm identified patients with positive predictive value (92%), specificity (100%), and sensitivity of 55%. The algorithm was applied to extract our target population from the Nationwide Readmissions Database. Univariate and multivariable analyses were used to identify factors influencing patient outcomes.

RESULTS

We identified 1235 operations for supratentorial (87%) or infratentorial (13%) CM surgery from the Nationwide Readmissions Database (2016-2017). The overall rate of adverse disposition and 30-day readmission were 19.7% and 7.5%, respectively. The rate of adverse disposition was significantly higher for infratentorial (vs. supratentorial cases) (34.3% vs. 17.6%, P = 0.001) and brainstem (vs. cerebellar) cases (55% vs. 28%, P = 0.03). Hospital case-volume percentile was associated with decreasing rates of adverse disposition (1-74th: 22%, 75th: 16%, 90th: 13%, 95th: 7%). Treatment at HVCs was also associated with shorter average length of stay (4.6 vs. 7.3 days, P < 0.001) without significant changes to average cost of hospitalization (P = 0.60).

CONCLUSIONS

Our ICD-10 coding algorithm reliably identifies CM surgery with minimal false positives. Outcomes were influenced by patient age, clinical presentation, location of CM, and experience of institution. Centralization of care may improve outcomes and warrants further investigation.

The history of neurosurgery at Baylor College of Medicine

The development of neurosurgery at Baylor College of Medicine began with the medical school's relocation to the new Texas Medical Center in Houston in 1943. An academic service was organized in 1949 as a section of neurosurgery within Baylor's Department of Surgery. Soon the practice, led by Dr. George Ehni, evolved to include clinical services at Methodist, Jefferson Davis (forerunner of Ben Taub), Texas Children's, the Veterans Affairs, and the University of Texas MD Anderson Cancer Center hospitals. A neurosurgery residency program was established in 1954. As the clinical practice expanded, neurosurgery was upgraded from a section to a division and then to a department. It has been led by four chiefs/chairs over the past 60 years-Dr. George Ehni (1959-1979), Dr. Robert Grossman (1980-2004), Dr. Raymond Sawaya (2005-2014), and Dr. Daniel Yoshor (2015-2020). Since the 1950s, the department has drawn strength from its robust residency program, its research base in the medical school, and its five major hospital affiliates, which have largely remained unchanged (with the exception of Baylor St. Luke's Medical Center replacing Methodist in 2004). The recent expansion of the residency program to 25 accredited positions and the growing strength of relationships with the "Baylor five" hospitals affiliated with Baylor College of Medicine portend a bright future.

Intracranial Solitary Fibrous Tumor of the Skull Base: 2 Cases and Systematic Review of the Literature

BACKGROUND

Intracranial solitary fibrous tumors (ISFTs) are rare neoplasms of mesenchymal origin that originate from the meninges. ISFTs of the skull base can be challenging to treat, as resection can be complicated by skull base anatomy. We present 2 cases of ISFT, the first manifesting with compressive cranial neuropathy from Meckel cave involvement and the second a posterior fossa lesion causing symptomatic hydrocephalus.

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed database was queried with title/abstract keywords "intracranial," "solitary fibrous tumor," "hemangiopericytoma," "SFT," and "HPC." Search results were reviewed to exclude cases not involving the skull base. References from all selected articles were reviewed for potential additional cases. Patient demographic and clinical data from 58 identified skull base cases were collected for qualitative synthesis.

RESULTS

Visual disturbances were the most common presenting symptom (30 cases, 52%) followed by headache (22 cases, 38%). The most common site of involvement was the sellar/parasellar region (18 cases, 31%) followed by middle fossa/temporal bone (14 cases, 24%). Resection was performed in 55 cases; gross total resection was reported in 26 cases (45%) and subtotal resection was reported in 21 cases (36%). Tumor recurrence was documented in 15 cases (26%) with median and mean follow-up periods of 16 and 29.9 months, respectively.

CONCLUSIONS

We discuss presentation, imaging, histopathology, and management considerations for ISFTs while highlighting the potentially complex nature of skull base lesions and need for multidisciplinary approach to treatment.

Fully Endoscopic Resection of an Epidermoid Cyst of the Cerebellopontine Angle: Bilateral Resection via a Unilateral Approach

BACKGROUND AND IMPORTANCE

Epidermoid cysts are rare, benign intracranial neoplasms that typically arise at the cerebellopontine angle (CPA) and can be extensive lesions that intricately involve many critical neurovascular structures. We describe the case of a patient who presents with the classic picture of CPA epidermoid cyst and describe the value of the 4K endoscope for resection, which is illustrated in our accompanying surgical video.

CLINICAL PRESENTATION

The patient presents with headache, nausea, and vomiting accompanied by dizziness and balance issues. Radiographic imaging demonstrated a large lesion highly consistent with epidermoid cyst which involved the left CPA, encircled the basilar artery, and extended to the opposite side. Surgery was planned with a small left-sided retrosigmoid craniotomy with use of a 2-dimensional 4K endoscope to aid in resection, particularly of the contralateral side. This approach was successful with gross total resection apparent at 14-mo follow-up.

CONCLUSION

We describe the use of a fully endoscopic technique from a unilateral approach for resection of a lesion that extended in the CPA bilaterally. Additionally, we highlight the relevant neuroanatomical and neurovascular structures in this highly critical intracranial region which is well-visualized through endoscopy in the associated surgical video.

Ambulatory neurosurgery in the COVID-19 era: patient and provider satisfaction with telemedicine

OBJECTIVE

Telemedicine has rapidly expanded in the recent years as technologies have afforded healthcare practitioners the ability to diagnose and treat patients remotely. Due to the COVID-19 pandemic, nonessential clinical visits were greatly limited, and much of the outpatient neurosurgical practice at the authors' institution was shifted quickly to telehealth. Although there are prior data suggesting that the use of telemedicine is satisfactory in other surgical fields, data in neurosurgery are limited. This study aimed to investigate both patient and provider satisfaction with telemedicine and its strengths and limitations in outpatient neurosurgery visits.

METHODS

This quality improvement study was designed to analyze provider and patient satisfaction with telemedicine consultations in an outpatient neurosurgery clinic setting at a tertiary care, large-volume, academic center. The authors designed an 11-question survey for neurosurgical providers and a 13-question survey for patients using both closed 5-point Likert scale responses and multiple choice responses. The questionnaires were administered to patients and providers during the period when the clinic restricted in-person visits. At the conclusion of the study, the overall data were analyzed qualitatively and quantitatively.

RESULTS

During the study period, 607 surveys were sent out to patients seen by telehealth at the authors' academic center, and 122 responses were received. For the provider survey, 85 surveys were sent out to providers at the authors' center and other academic centers, and 40 surveys were received. Ninety-two percent of patients agreed or strongly agreed that they were satisfied with that particular telehealth visit. Eighty-eight percent of patients agreed that their telehealth visit was more convenient for them than an in-person visit, but only 36% of patients stated they would like their future visits to be telehealth. Sixty-three percent of providers agreed that telehealth visits were more convenient for them than in-person visits, and 85% of responding providers stated that they wished to incorporate telehealth into their future practice.

CONCLUSIONS

Although the authors' transition to telehealth was both rapid and unexpected, most providers and patients reported positive experiences with their telemedicine visits and found telemedicine to be an effective form of ambulatory neurosurgical care. Not all patients preferred telemedicine visits over in-person visits, but the high satisfaction with telemedicine by both providers and patients is promising to the future expansion of telehealth in ambulatory neurosurgery.