Faculty Bibliography

OBJECTIVES/OBJECTIVE:To assess a decade of experience of treating patients with high hearing risk cerebellopontine angle (CPA) epidermoid lesions and examine factors influencing postoperative outcomes, particularly hearing preservation. STUDY DESIGN/METHODS:Retrospective chart review. SETTING/METHODS:Single tertiary-referral center. PATIENTS/METHODS:Adults with CPA epidermoid lesions who presented with hearing loss or evidence of lesion involving vestibulocochlear nerve. INTERVENTIONS/METHODS:The studied intervention was microsurgical resection. MAIN OUTCOME MEASURES/METHODS:Main outcome measures included extent of resection, hearing preservation rate for patients with postoperative audiograms, and disease progression. RESULTS:Twenty-three adults with an average tumor volume of 15.63 ± 16.2 cm3 were included. Five lesions (22%) involved the full internal auditory canal (IAC), 11 (48%) had partial involvement, and 5 (22%) were IAC sparing. Most patients with IAC involvement (88%) had circumferential invasion of the canal. Patients underwent either a retrosigmoid (18, 79%) or combined retrolabyrinthine transpetrosal approach (5, 22%), and gross total resection was achieved in most cases (13, 57%). Of 12 patients with postoperative audiograms, 10 (83%) had preoperative hearing preserved. There was no statistically significant change in hearing scores with treatment based on preoperative extent of IAC involvement. Ten patients (43%) had residual lesions postoperatively, and 6 exhibited progression. One patient ultimately required reoperation 6 years after initial surgery. CONCLUSIONS:Preoperative hearing was preserved in the majority of the patients who underwent resection of CPA epidermoids via a retrosigmoid or transpetrosal approach. CPA epidermoids often invaded the IAC; however, degree of invasion was not associated with hearing outcomes.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The management of World Health Organization (WHO) grade 2 meningiomas is complicated by their diverse clinical behaviors. Stereotactic radiosurgery (SRS) can be an effective management option. Literature on SRS dose selection is limited but suggests that a higher dose is better for tumor control. We characterize the predictors of post-SRS outcomes that can help guide planning and management. METHODS:We reviewed a cohort of consecutive patients with pathologically-proven WHO grade 2 meningiomas who underwent SRS at a single institution between 2011 and 2023. RESULTS:Ninety-nine patients (median age 62 years) underwent SRS, 11 of whom received hypofractionated SRS in 5 fractions. Twenty-two patients had received previous irradiation. The median follow-up was 49 months. The median overall survival was 119 months (95% CI 92-NA) with estimated 5- and 10-year survival of 83% and 27%, respectively. The median progression-free survival (PFS) was 40 months (95% CI 32-62), with 3- and 5-year rates at 54% and 35%, respectively. The median locomarginal PFS was 63 months (95% CI 51.8-NA) with 3- and 5-year rates at 65% and 52%. Nine (9%) patients experienced adverse events, 2 Common Terminology Criteria for Adverse Events grade 3 and 7 grade 2, consisting of worsening neurologic deficit from edema. In the single-session cohort, Ki-67 significantly predicted both overall survival and intracranial PFS. Tumors with Ki-67 >10% had 2.17 times the risk of locomarginal progression compared with Ki-67 ≤10% (P = .018) adjusting for covariates. Sex, prescription dose, tumor volume, and location also predicted tumor control. In tumors with Ki-67 >10%, margin dose ≥14 Gy was associated with significantly better tumor control but not for tumors with Ki-67 ≤10%. CONCLUSION/CONCLUSIONS:The management of WHO grade 2 meningiomas requires a multimodality approach. This study demonstrates the value of a targeted SRS approach in patients with limited disease and further establishes predictive biomarkers that can guide planning through a personalized approach.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Communication has a well-established effect on improving outcomes. The current study evaluated the effect of multidisciplinary preoperative team communication using a digital huddle software platform on operating room costs. METHODS:A digital huddle software platform was implemented in March 2022 for neurosurgical procedures performed at a single tertiary care center. Surgeons were encouraged, but not required, to participate. General linear models were used to test the association between participation and the difference in supply-related cost and case length, using intergroup comparison and historical controls. RESULTS:A total of 29626 cases (performed by 97 surgeons), conducted between March 2021 and June 2023, were included in our analysis. Cases from participating neurosurgeons (12 surgeons, 4064 cases) were compared with cases from nonparticipating neurosurgeons (6 surgeons, 2452 cases), non-neurosurgery cases carried out by the same operating room staff (20 orthopedic spine surgeons, 6073 cases), and non-neurosurgery cases performed in a different operating room unit (59 surgeons, 21 996 cases). In aggregate, operating room (OR) costs increased by 7.3% (95% CI: 0.9-14.1, P = .025) in the postintervention period. In the same period, participation in the digital huddle platform was associated with an OR utilization and supply-related cost decrease of 16.3% (95% CI: 8.3%-23.6%, P < .001). Among neurosurgeons specifically, participation was associated with a supply-related cost decrease of 17.5% (95% CI: 6.0%-27.5%, P = .0037). There was no change in case length (median case length 171 minutes, change: +2.7% increase, 95% CI:-2.2%-7.9%, P = .28). CONCLUSION/CONCLUSIONS:The implementation of a digital huddle software platform resulted in an OR utilization and supply cost decrease among participants during a period when the overall nonparticipating control cohort experienced an increase in cost.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Iatrogenic cerebrovascular injury can cause intracranial hemorrhage and pseudoaneurysm formation, putting patients at high risk for postoperative bleeding. No consensus for management exists. This study describes endovascular treatment of these acute injuries with flow diverter stents. METHODS:Electronic medical records were retrospectively reviewed for injury type and etiology, timing of diagnosis, and endovascular management, including antiplatelet regimens, embolization results, and clinical outcome. RESULTS:Six patients were included. Three suffered an injury to the internal carotid artery, 1 suffered an injury to the left anterior cerebral artery, 1 suffered an injury to the right posterior cerebral artery, and 1 suffered an injury to the basilar artery. Four of the 6 injuries occurred during attempted tumor resection, 1 occurred during cerebrospinal fluid leak repair, and 1 occurred during an ophthalmic artery aneurysm clipping. All injuries resulted in pseudoaneurysm formation. Four were immediately detected on angiography; 2 were initially negative on imaging. Five were treated with a pipeline embolization device, and 1 was treated with a Silk Vista Baby. Two were treated with 2 pipeline embolization devices telescopically overlapped across the pseudoaneurysm. All devices deployed successfully. No pseudoaneurysm recurrence or rebleeding occurred. No parent artery occlusion or stenosis was observed, and complete pseudoaneurysm occlusion was observed in 4 patients (in 2 patients, follow-up imaging could not be obtained). CONCLUSION/CONCLUSIONS:With proper antiplatelet regimens, flow diverter stents can be used safely to successfully treat complex acute iatrogenic injuries. Early repeat angiogram is needed when immediate postinjury imaging does not discover the point of vessel injury.

BACKGROUND:Isocitrate dehydrogenase (IDH) mutant astrocytoma grading, until recently, has been entirely based on morphology. The 5th edition of the Central Nervous System World Health Organization (WHO) introduces CDKN2A/B homozygous deletion as a biomarker of grade 4. We sought to investigate the prognostic impact of DNA methylation-derived molecular biomarkers for IDH mutant astrocytoma. METHODS:We analyzed 98 IDH mutant astrocytomas diagnosed at NYU Langone Health between 2014 and 2022. We reviewed DNA methylation subclass, CDKN2A/B homozygous deletion, and ploidy and correlated molecular biomarkers with histological grade, progression free (PFS), and overall (OS) survival. Findings were confirmed using 2 independent validation cohorts. RESULTS:There was no significant difference in OS or PFS when stratified by histologic WHO grade alone, copy number complexity, or extent of resection. OS was significantly different when patients were stratified either by CDKN2A/B homozygous deletion or by DNA methylation subclass (P value = .0286 and .0016, respectively). None of the molecular biomarkers were associated with significantly better PFS, although DNA methylation classification showed a trend (P value = .0534). CONCLUSIONS:The current WHO recognized grading criteria for IDH mutant astrocytomas show limited prognostic value. Stratification based on DNA methylation shows superior prognostic value for OS.

The most widely used fluorophore in glioma-resection surgery, 5-aminolevulinic acid (5-ALA), is thought to cause the selective accumulation of fluorescent protoporphyrin IX (PpIX) in tumour cells. Here we show that the clinical detection of PpIX can be improved via a microscope that performs paired stimulated Raman histology and two-photon excitation fluorescence microscopy (TPEF). We validated the technique in fresh tumour specimens from 115 patients with high-grade gliomas across four medical institutions. We found a weak negative correlation between tissue cellularity and the fluorescence intensity of PpIX across all imaged specimens. Semi-supervised clustering of the TPEF images revealed five distinct patterns of PpIX fluorescence, and spatial transcriptomic analyses of the imaged tissue showed that myeloid cells predominate in areas where PpIX accumulates in the intracellular space. Further analysis of external spatially resolved metabolomics, transcriptomics and RNA-sequencing datasets from glioblastoma specimens confirmed that myeloid cells preferentially accumulate and metabolize PpIX. Our findings question 5-ALA-induced fluorescence in glioma cells and show how 5-ALA and TPEF imaging can provide a window into the immune microenvironment of gliomas.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Instrumented spinal fusion constructs sometimes fail because of fatigue loading, frequently necessitating open revision surgery. Favorable outcomes after percutaneous juxtapedicular cement salvage (perc-cement salvage) of failing instrumentation have been described; however, this approach is not widely known among spine surgeons , and its biomechanical properties have not been evaluated. We report our institutional experience with perc-cement salvage and investigate the relative biomechanical strength of this technique as compared with 3 other common open revision techniques. METHODS:A retrospective chart review of patients who underwent perc-cement salvage was conducted. Biomechanical characterization of revision techniques was performed in a cadaveric model of critical pedicle screw failure. Three revision cohorts involved removal and replacement of hardware: (1) screw upsizing, (2) vertebroplasty, and (3) fenestrated screw with cement augmentation. These were compared with a cohort with perc-cement salvage performed using a juxtapedicular trajectory with the failed primary screw remaining engaged in the vertebral body. RESULTS:Ten patients underwent perc-cement salvage from 2018 to 2022 to address screw haloing and/or endplate fracture threatening construct integrity. Pain palliation was reported by 8/10 patients. Open revision surgery was required in 4/10 patients, an average of 8.9 months after the salvage procedure (range 6.2-14.7 months). Only one revision was due to progressive hardware dislodgement. The remainder avoided open revision surgery through an average of 1.9 years of follow-up. In the cadaveric study, there were no significant differences in pedicle screw pullout strength among any of the revision cohorts. CONCLUSION/CONCLUSIONS:Perc-cement salvage of failing instrumentation is reasonably efficacious. The technique is biomechanically noninferior to other revision strategies that require open surgery for removal and replacement of hardware. Open revision surgery may be avoided by perc-cement salvage in select cases.

Objectives To characterize treatment and hearing outcomes for cerebellopontine angle (CPA) meningiomas with inherent risks of hearing loss and identify predictors of hearing loss for surgically treated lesions. Design Retrospective chart review. Setting Tertiary care medical center. Participants Adult patients with CPA meningiomas impinging upon cranial nerve VIII and/or pretreatment hearing loss managed with microsurgery or stereotactic radiosurgery (SRS) with Gamma Knife at our center between 2012 and 2023. Main Outcome Measures Hearing preservation rate was determined from analysis of patients with pretreatment serviceable hearing for whom hearing-preserving treatment was attempted. Surgical patients were further analyzed using multivariable Cox proportional hazards regression models to identify factors predictive of postoperative hearing loss. Results We identified 80 patients with CPA meningiomas meeting inclusion criteria who were managed with either microsurgery (43, 54%) or radiosurgery (37, 46%). Following SRS, hearing was preserved in 88% of cases. Following microsurgery, hearing was preserved in 71% of patients-all patients who lost hearing had tumors involving the internal auditory canal (IAC). Among surgical patients only, multivariable analysis accounting for preoperative hearing, recurrence status, lesion size, and patient age, the preoperative imaging finding that the CPA meningioma surrounded the vestibulocochlear nerve was significantly associated with hearing loss (hazard ratio: 10.3, 95% confidence interval: 1.3-81.4, p = 0.02). Conclusion Most patients with meningiomas of the CPA can experience preservation of hearing, even when there is risk of hearing loss based on pretreatment evaluation. IAC invasion and surrounding of eighth nerve by tumor may portend poorer hearing outcomes in surgically managed patients.

UNLABELLED:Acromegaly is a rare endocrine disorder caused by hypersecretion of growth hormone (GH) from a pituitary adenoma. Elevated GH levels stimulate excess production of insulin-like growth factor 1 (IGF-1) which leads to the insidious onset of clinical manifestations. The most common primary central nervous system (CNS) tumors, meningiomas originate from the arachnoid layer of the meninges and are typically benign and slow-growing. Meningiomas are over twice as common in women as in men, with age-adjusted incidence (per 100,000 individuals) of 10.66 and 4.75, respectively. Several reports describe co-occurrence of meningiomas and acromegaly. We aimed to determine whether patients with acromegaly are at elevated risk for meningioma. Investigation of the literature showed that co-occurrence of a pituitary adenoma and a meningioma is a rare phenomenon, and the majority of cases involve GH-secreting adenomas. To the best of our knowledge, a systematic review examining the association between meningiomas and elevated GH levels (due to GH-secreting adenomas in acromegaly or exposure to exogenous GH) has never been conducted. The nature of the observed coexistence between acromegaly and meningioma -whether it reflects causation or mere co-association -is unclear, as is the pathophysiologic etiology. SYSTEMATIC REVIEW REGISTRATION/UNASSIGNED:https://www.crd.york.ac.uk/prospero/, identifier CRD42022376998.