Identifying risk factors for postoperative diabetes insipidus in more than 2500 patients undergoing transsphenoidal surgery: a single-institution experience

OBJECTIVE

Diabetes insipidus (DI) following transsphenoidal surgery can adversely impact quality of life and be difficult to manage. This study sought to characterize pre- and perioperative risk factors that may predispose patients to DI after pituitary surgery.

METHODS

A retrospective review of patients treated at a single institution from 2007 to 2019 was conducted. DI was defined as postoperative sodium > 145 mEq/L and urine output > 300 ml/hr and/or postoperative desmopressin (ddAVP) use. DI was further characterized as transient or permanent. Uni- and multivariate analyses were performed to determine variables associated with postoperative DI.

RESULTS

The authors identified 2529 patients who underwent transsphenoidal surgery at their institution. Overall, DI was observed in 270 (10.7%) of the 2529 patients, with 114 (4.5%) having permanent DI and 156 (6.2%) with transient symptoms. By pathology type, DI occurred in 31 (46.3%) of 67 craniopharyngiomas, 10 (14.3%) of 70 apoplexies, 46 (14.3%) of 322 Rathke's cleft cysts, 77 (7.7%) of 1004 nonfunctioning pituitary adenomas (NFPAs), and 62 (7.6%) of 811 functioning pituitary adenomas (FPAs). Final lesion pathology significantly affected DI rates (p < 0.001). Multivariate analysis across pathologies showed that younger age (odds ratio [OR] 0.97, p < 0.001), intraoperative CSF encounter (OR 2.74, p < 0.001), craniopharyngioma diagnosis (OR 8.22, p = 0.007), and postoperative hyponatremia (OR 1.50, p = 0.049) increased the risk of DI. Because surgery for each pathology created specific risk factors for DI, the analysis was then limited to the 1815 pituitary adenomas (PAs) in the series, comprising 1004 NFPAs and 811 FPAs. For PAs, younger age (PA: OR 0.97, p < 0.001; NFPA: OR 0.97, p < 0.001; FPA: OR 0.97, p = 0.028) and intraoperative CSF encounter (PA: OR 2.99, p < 0.001; NFPA: OR 2.93, p < 0.001; FPA: OR 3.06, p < 0.001) increased DI rates in multivariate analysis. Among all PAs, patients with DI experienced peak sodium levels later than those without DI (postoperative day 11 vs 2). Increasing tumor diameter increased the risk of DI in FPAs (OR 1.52, p = 0.008), but not in NFPAs (p = 0.564).

CONCLUSIONS

In more than 2500 patients treated at a single institution, intraoperative CSF encounter, craniopharyngioma diagnosis, and young age all increased the risk of postoperative DI. Patients with postoperative hyponatremia exhibited higher rates of DI, suggesting possible bi- or triphasic patterns to DI. Greater vigilance should be maintained in patients meeting these criteria following transsphenoidal surgery to ensure early recognition and treatment of DI.

Socioeconomic predictors of case presentations and outcomes in 225 nonfunctional pituitary adenoma resections

OBJECTIVE

Clinical presentations and outcomes of nonfunctional pituitary adenoma (NFPA) resections can vary widely, and very little prior research has analyzed this variance through a socioeconomic lens. This study sought to determine whether socioeconomic status (SES) influences NFPA presentations and postoperative outcomes, as these associations could aid physicians in understanding case prognoses and complications.

METHODS

The authors retrospectively analyzed 225 NFPA resections from 2012 to 2019 at their institution. Race, ethnicity, insurance status, estimated income, and having a primary care provider (PCP) were collected as 5 markers of SES. These markers were correlated with presenting tumor burden, presenting symptoms, surgical outcomes, and long-term clinical outcomes.

RESULTS

All 5 examined SES markers influenced variance in patient presentation or outcome. Insurance status's effects on patient presentations disappeared when examining only patients with PCPs. Having a PCP was associated with significantly smaller tumor size at diagnosis (effect size = 0.404, p < 0.0001). After surgery, patients with PCPs had shorter postoperative hospital lengths of stay (p = 0.043) and lower rates of readmission within 30 days of discharge (OR 0.256, p = 0.047). Despite continuing follow-up for longer durations (p = 0.0004), patients with PCPs also had lower rates of tumor recurrence (p < 0.0001). Higher estimated income was similarly associated with longer follow-up (p = 0.002) and lower rates of tumor recurrence (p = 0.013). Among patients with PCPs, income was not associated with recurrence.

CONCLUSIONS

This study found that while all 5 variables (race, ethnicity, insurance, PCP status, and estimated income) affected NFPA presentations and outcomes, having a PCP was the single most important of these socioeconomic factors, impacting hospital lengths of stay, readmission rates, follow-up adherence, and tumor recurrence. Having a PCP even protected low-income patients from experiencing increased rates of tumor recurrence. These protective findings suggest that addressing socioeconomic disparities may lead to better NFPA presentations and outcomes.

Salvage Surgery for Local Control of Brain Metastases After Previous Stereotactic Radiosurgery: A Single-Center Series

BACKGROUND

Although overall survival (OS) has improved in patients with brain metastases (BMs), control of recurrent BMs remains a therapeutic challenge. Salvage surgery may achieve acceptable control rates in the setting of progression after previous stereotactic radiosurgery (SRS), yet it remains a question how additional adjuvant therapies may affect outcomes and how patient selection for salvage surgery may be optimized.

METHODS

Patients receiving salvage surgery for BM progression after previous SRS were retrospectively reviewed from a single center. Outcomes of interest included local tumor progression, leptomeningeal dissemination, and OS. Cox proportional hazard models and nominal logistic regression were applied to determine factors associated with outcomes of interest.

RESULTS

A total of 43 patients with 50 BMs were included. After salvage surgery, local progression was observed for 17 BMs (34%), leptomeningeal dissemination was observed in 17 patients (39.5%), and censored median OS was 17.9 months. On multivariate analysis, use of brachytherapy was associated with improved local control (hazard ratio [HR], 0.15; 95% confidence interval [CI], 0.04-0.6; P = 0.008). For patients treated with SRS ≥4.5 months before salvage surgery, both brachytherapy (HR, 0.07; 95% CI, 0.01-0.39; P = 0.002) and postoperative adjuvant SRS (HR, 0.14; 95% CI, 0.02-1.00; P = 0.05) were associated with improved local control compared with no adjuvant radiation therapy. Presence of extracranial malignancy (HR, 6.70; 95% CI, 2.58-17.42; P < 0.0001) was associated with shorter survival. Graded prognostic assessment underestimated survival in 79.1% of patients, with a mean difference of 18.9 months between graded prognostic assessment-estimated and actual OS.

CONCLUSIONS

In properly selected patients, salvage surgery may be an appropriate therapy for BM progression after previous SRS. Adjuvant brachytherapy and repeat SRS can offer significant benefit for local control with salvage resection.

Microsurgical resection of an intravestibular schwannoma: a review of surgical technique and management considerations

Intravestibular schwannomas are rare tumors within the intralabyrinthine region and involve different management considerations compared to more common vestibular schwannomas. In this report, the authors review a case of a 52-year-old woman who presented with hearing loss and vestibular symptoms and was found to have a left intravestibular schwannoma. Given her debilitating vestibular symptoms, she underwent microsurgical resection. In this video, the authors review the relevant anatomy, surgical technique, and management considerations in these patients.

The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2187

Comparison of Outcomes following Primary and Repeat Resection of Craniopharyngioma

Introduction The management of recurrent craniopharyngioma is complex with limited data to guide decision-making. Some reports suggest reoperation should be avoided due to an increased complication profile, while others have demonstrated that safe reoperation can be performed. For other types of skull base lesions, maximal safe resection followed by adjuvant therapy has replaced radical gross total resection due to the favorable morbidity profiles.

Methods Seventy-one patients underwent resection over a 9-year period for craniopharyngioma and were retrospectively reviewed. Patients were separated into primary resection and reoperation cohorts and stratified by surgical approach (endonasal vs. cranial) and survival analyses were performed based on cohort and surgical approach.

Results Fifty patients underwent primary resection, while 21 underwent reoperation for recurrence. Fifty endonasal transsphenoidal surgeries and 21 craniotomies were performed. Surgical approaches were similarly distributed across cohorts. Subtotal resection was achieved in 83% of all cases. There were no differences in extent of resection, visual outcomes, subsequent neuroendocrine function, and complications across cohorts and surgical approaches. The median time to recurrence was 87 months overall, and there were no differences by cohort and approach. The 5-year survival rate was 81.1% after reoperation versus 93.2% after primary resection.

Conclusion Compared with primary resection, reoperation for craniopharyngioma recurrence is associated with similar functional and survival outcomes in light of individualized surgical approaches. Maximal safe resection followed by adjuvant radiotherapy for residual tumor likely preserves vision and endocrine function without sacrificing overall patient survival.

Posterior petrous face meningiomas presenting with Ménière's-like syndrome: a case series and review of the literature

OBJECTIVE

Ménière's disease is an inner ear disorder classically characterized by fluctuating hearing loss, tinnitus, and aural fullness accompanied by episodic vertigo. While the pathogenesis of Ménière's remains under debate, histopathological analyses implicate endolymphatic sac dysfunction with inner ear fluid homeostatic dysregulation. Little is known about whether external impingement of the endolymphatic sac by tumors may present with Ménière's-like symptoms. The authors present a case series of 7 patients with posterior fossa meningiomas that involved the endolymphatic sac and new onset of Ménière's-like symptoms and review the literature on this rare clinical entity.

METHODS

A retrospective review of patients undergoing resection of a posterior petrous meningioma was performed at the authors' institution. Inclusion criteria were age older than 18 years; patients presenting with Ménière's-like symptoms, including episodic vertigo, aural fullness, tinnitus, and/or hearing loss; and tumor location overlying the endolymphatic sac.

RESULTS

There were 7 cases of posterior petrous face meningiomas involving the vestibular aperture presenting with Ménière's-like symptoms. Imaging and intraoperative examination confirmed no cranial nerve VIII compression or labyrinthine artery involvement accounting for audiovestibular symptoms. Of the 7 patients in the series, 6 experienced significant improvement or resolution of their vertigo, and all 7 had improvement or resolution of their tinnitus after resection. Of the 5 patients who had preoperative hearing loss, 2 experienced improvement or resolution of their ipsilateral preoperative hearing deficit, whereas the other 3 had unchanged hearing loss compared to preoperative evaluation.

CONCLUSIONS

Petrous face meningiomas overlying the endolymphatic sac can present with a Ménière's syndrome. Early recognition and microsurgical excision of these tumors is critical for resolution of most symptoms and stabilization of hearing loss.

Clinical characteristics and outcomes of null-cell versus silent gonadotroph adenomas in a series of 1166 pituitary adenomas from a single institution

OBJECTIVE

Nonfunctioning pituitary adenomas present without biochemical or clinical signs of hormone excess and are the second most common type of pituitary adenomas. The 2017 WHO classification scheme of pituitary adenomas differentiates null-cell adenomas (NCAs) and silent gonadotroph adenomas (SGAs). The present study sought to highlight the differences in patient characteristics and clinical outcomes between NCAs and SGAs.

METHODS

The records of 1166 patients who underwent transsphenoidal surgery for pituitary adenoma between 2012 and 2019 at a single institution were retrospectively reviewed. Patient demographics and clinical outcomes were collected.

RESULTS

Of the overall pituitary adenoma cohort, 12.8% (n = 149) were SGAs and 9.2% (n = 107) NCAs. NCAs were significantly more common in female patients than SGAs (61.7% vs 26.8%, p < 0.001). There were no differences in patient demographics, initial tumor size, or perioperative and short-term clinical outcomes. There was no significant difference in the amount of follow-up between patients with NCAs and those with SGAs (33.8 months vs 29.1 months, p = 0.237). Patients with NCAs had significantly higher recurrence (p = 0.021), adjuvant radiation therapy usage (p = 0.002), and postoperative diabetes insipidus (p = 0.028). NCA pathology was independently associated with tumor recurrence (HR 3.64, 95% CI 1.07-12.30; p = 0.038), as were cavernous sinus invasion (HR 3.97, 95% CI 1.04-15.14; p = 0.043) and anteroposterior dimension of the tumor (HR 2.23, 95% CI 1.09-4.59; p = 0.030).

CONCLUSIONS

This study supports the definition of NCAs and SGAs as separate subgroups of nonfunctioning pituitary adenomas, and it highlights significant differences in long-term clinical outcomes, including tumor recurrence and the associated need for adjuvant radiation therapy, as well as postoperative diabetes insipidus. The authors also provide insight into independent risk factors for these outcomes in the adenoma population studied, providing clinicians with additional predictors of patient outcomes. Follow-up studies will hopefully uncover mechanisms of biological aggressiveness in NCAs and associated molecular targets.

Oncology and Spinal Neurosurgeons Performing Resections of Intramedullary Ependymomas Compared with Single Neurosurgeons: A 13-Year Experience at a Single Institution

OBJECTIVE

Resection of intramedullary spinal ependymomas carries great risk of postoperative neurological deficits. The objective of this study was to describe our experience using co-neurosurgeon teams to address intramedullary ependymomas to determine if the use of 2 experienced attending neurosurgeons with expertise in both neurosurgical oncology and spine pathology can improve outcomes for intramedullary ependymoma resections.

METHODS

We retrospectively compared surgical and disease control outcomes in intramedullary ependymoma cases performed by co-neurosurgeon (one neurosurgical oncologist and one neurosurgeon trained in spinal surgery) and single-neurosurgeon teams over a 13-year period at a single institution.

RESULTS

Co-neurosurgeons performed resections in 34 (47.9%) patients, and a single neurosurgeon performed resections in 37 (52.1%) patients. There were no significant differences in the frequency of gross total resection in the co-neurosurgeon versus single-neurosurgeon group (85.7% vs. 78.4%, P = 0.45). Posterior spinal fusion was more common in the co-neurosurgeon group (35.3%) compared with the single-neurosurgeon group (8.1%) (P = 0.01). Two (5.9%) patients in the co-neurosurgeon group and 5 (13.5%) patients in the single-neurosurgeon group had complications requiring surgical revision (P = 0.28). Recurrence rates were similar in both groups (5.9% vs. 10.8%, P = 0.50). At last follow-up, 76% of patients who presented with mild or no deficits remained functionally independent.

CONCLUSIONS

Resection of intramedullary ependymomas by co-neurosurgeon teams resulted in similar rates of gross total resection, postoperative complications, and recurrence compared with surgeries performed by a single neurosurgeon. Functional neurological outcomes were not impacted by co-neurosurgeons performing ependymoma resections.

Are preoperative chlorhexidine gluconate showers associated with a reduction in surgical site infection following craniotomy? A retrospective cohort analysis of 3126 surgical procedures

OBJECTIVE

Surgical site infection (SSI) is a complication linked to increased costs and length of hospital stay. Prevention of SSI is important to reduce its burden on individual patients and the healthcare system. The authors aimed to assess the efficacy of preoperative chlorhexidine gluconate (CHG) showers on SSI rates following cranial surgery.

METHODS

In November 2013, a preoperative CHG shower protocol was implemented at the authors' institution. A total of 3126 surgical procedures were analyzed, encompassing a time frame from April 2012 to April 2016. Cohorts before and after implementation of the CHG shower protocol were evaluated for differences in SSI rates.

RESULTS

The overall SSI rate was 0.6%. No significant differences (p = 0.11) were observed between the rate of SSI of the 892 patients in the preimplementation cohort (0.2%) and that of the 2234 patients in the postimplementation cohort (0.8%). Following multivariable analysis, implementation of preoperative CHG showers was not associated with decreased SSI (adjusted OR 2.96, 95% CI 0.67-13.1; p = 0.15).

CONCLUSIONS

This is the largest study, according to sample size, to examine the association between CHG showers and SSI following craniotomy. CHG showers did not significantly alter the risk of SSI after a cranial procedure.

Abstract PO-073: Mutational status and clinical outcomes following systemic therapy and focal radiation for melanoma brain metastases

Brain metastases are the most common intracranial neoplasm yet clinical outcomes remain poor. The purpose of this study was to evaluate the efficacy of multimodal therapy comprising surgery followed by focal radiation, and/or systemic therapy and elucidate clinically significant biomarkers for resected melanoma brain metastases. Forty consecutive patients with newly diagnosed melanoma brain metastases who underwent surgical resection and targeted mutational analysis at UCSF between 2011 and 2020 were identified. Demographic, clinical, and outcome data were extracted from the medical record and institutional cancer registry. Surgical cavity local recurrence free survival (LRFS), intracranial progression free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. The median age of patients in this cohort was 58 years (range: 27-75 years) with median MRI follow up of 13.15 months. Twenty patients (50%) were treated with concurrent stereotactic radiation (1-5 fractions) and systemic therapy while 16 patients (40%) were treated with systemic therapy only. Mutational testing demonstrated the most common pathogenic variant was BRAF V600E, found in 16 patients (40%), while the remaining 24 patients (60%) did not harbor this mutation. Microsatellite instability (MSI) estimation was available for 8 patients (20%), all of which were found to be MSI low (&lt;2%). Median LRFS was significantly improved with combined focal radiation and systemic therapy compared to systemic therapy alone (NR versus 15 months, p=0.01; log-rank test). Patients harboring BRAF V600E mutations had worse intracranial PFS compared to those without V600E mutation (4 months versus 12 months, p=0.048; log-rank test), as well as a trend toward worse OS (NR vs 13 months, p=0.09; log-rank test). Systemic agent choice was heterogeneous, with 24 patients (60%) treated with immunotherapy alone, 12 patients (30%) treated with dual BRAF/MEK inhibitor therapy alone, and the remainder treated with mixed regimens (10%) with no differences in efficacy or toxicity between these subgroups. Our results suggest combined focal radiation and systemic therapy is effective for melanoma brain metastases. Moreover, specific molecular alterations such as BRAF V600E mutation are associated with poorer outcomes, and all brain metastases in our cohort were MSI low. Limitations of our study include its retrospective nature, limited sample size, and heterogeneity of systemic regimens, and future prospective validation and multiplatform genomic analysis are needed to build on our findings.

Citation Format: Harish N. Vasudevan, Matthew S. Susko, Lijun Ma, Jean L. Nakamura, David R. Raleigh, Lauren Boreta, Shannon Fogh, Philip V. Theodosopoulos, Michael W. McDermott, Katy K. Tsai, Penny K. Sneed, Steve E. Braunstein. Mutational status and clinical outcomes following systemic therapy and focal radiation for melanoma brain metastases [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-073.

Genetic Events and Signaling Mechanisms Underlying Schwann Cell Fate in Development and Cancer

In this review, we describe Schwann cell development from embryonic neural crest cells to terminally differentiated myelinated and nonmyelinated mature Schwann cells. We focus on the genetic drivers and signaling mechanisms mediating decisions to proliferate versus differentiate during Schwann cell development, highlighting pathways that overlap with Schwann cell development and are dysregulated in tumorigenesis. We conclude by considering how our knowledge of the events underlying Schwann cell development and mouse models of schwannoma, neurofibroma, and malignant peripheral nerve sheath tumor can inform novel therapeutic strategies for patients with cancers derived from Schwann cell lineages.

Meningioma surgical outcomes and complications in patients aged 75 years and older

OBJECTIVE

Meningioma incidence increases with age, yet limited data exist on how comorbidities impact complication rates in elderly patients undergoing meningioma resection. The objective of this study was to report surgical outcomes and identify risk factors for perioperative complications.

METHODS

We performed a retrospective study of patients 75 years and older undergoing meningioma resection. Outcomes included survival and complications. Major complications were those requiring surgical intervention or causing permanent neurological deficit. Recursive partitioning, Kaplan-Meier survival, univariate and multi-variate (MVA) analyses were performed.

RESULTS

From 1996 to 2014, 103 patients with a median age of 79 years (IQR 77-83 years) underwent cranial meningioma resection. Median follow-up was 5.8 years (IQR 1.7-8.7 years). Median actuarial survival was 10.5 years. Complications occurred in 32 patients (31.1%), and 13 patients (12.6%) had multiple complications. Major complications occurred in 16 patients (15.5%). Increasing age was not a significant predictor of any (p = 0.6408) or major complication (p = 0.8081). On univariate analysis, male sex, Charlson Comorbidity Index greater than 8, and cardiovascular comorbidities were significantly associated with major complications. On MVA only cardiovascular comorbidities (OR 3.94, 95% CI 1.05-14.76, p = 0.0238) were significantly associated with any complication. All patients with major complications had cardiovascular comorbidities, and on MVA male gender (OR 3.78, 95%CI 1.20-11.93, p = 0.0212) was associated with major complications.

CONCLUSIONS

Cardiovascular comorbidities and male gender are significant risk factors for complications after meningioma resection in patients aged 75 years and older. While there is morbidity associated with meningioma resection in this cohort, there is also excellent long-term survival.

Use of Ultrasound for Navigating the Internal Carotid Artery in Revision Endoscopic Endonasal Skull Base Surgery

While the use of image-guided navigation is an excellent adjunct to the use of anatomical landmarks, dynamic changes that may occur in the position of critical structures are not accounted for during and after tumor resection. Unlike navigation, Doppler ultrasonography provides real-time imaging of the anterior skull base and can be used to accurately identify the location of vital structures during skull base surgery.

A 56-year-old female initially presented with new onset left eye visual deficits. She previously underwent sublabial transsphenoidal subtotal resection of the tumor, confirmed as clival chordoma. She subsequently presented to our institution. She was treated with an expanded endonasal resection of the remaining chordoma followed by CyberKnife radiosurgery. Two years later, surveillance imaging identified tumor recurrence within the right clivus posterior to the carotid artery. Intraoperatively, in the previously operated irradiated skull base, the normal bony architecture of the sella was absent, resulting in the inability to distinguish the anterior genu of the internal carotid artery (ICA) from the adjacent tumor. Using Doppler ultrasonography, the course of the ICA was imaged in real time, allowing for safe, gross total tumor resection.

In the setting of prior operation, radiation, or extensive disease, the normal bony architecture of the sella may be disrupted, placing the cavernous ICA at risk. We report what we believe is the first use of intraoperative ultrasound during the endoscopic endonasal approach in the setting of a previously operated, radiated sella.

Postoperative diffusion-weighted imaging and neurological outcome after convexity meningioma resection

OBJECTIVE

Convexity meningiomas are commonly managed with resection. Motor outcomes and predictors of new deficits after surgery are poorly studied. The objective of this study was to determine whether postoperative diffusion-weighted imaging (DWI) was associated with neurological deficits after convexity meningioma resection and to identify the risk factors for postoperative DWI restriction.

METHODS

A retrospective review of patients who had undergone convexity meningioma resection from 2014 to 2018 was performed. Univariate and multivariate logistic regressions were performed to identify variables associated with postoperative neurological deficits and a DWI signal. The amount of postoperative DWI signal was measured and was correlated with low apparent diffusion coefficient maps to confirm ischemic injury.

RESULTS

The authors identified 122 patients who had undergone a total of 125 operations for convexity meningiomas. The median age at surgery was 57 years, and 70% of the patients were female. The median follow-up was 26 months. The WHO grade was I in 62% of cases, II in 36%, and III in 2%. The most common preoperative deficits were seizures (24%), extremity weakness/paralysis (16%), cognitive/language/memory impairment (16%), and focal neurological deficit (16%). Following resection, 89% of cases had no residual deficit. Postoperative DWI showed punctate or no diffusion restriction in 78% of cases and restriction > 1 cm in 22% of cases. An immediate postoperative neurological deficit was present in 14 patients (11%), but only 8 patients (7%) had a deficit at 3 months postoperatively. Univariate analysis identified DWI signal > 1 cm (p < 0.0001), tumor diameter (p < 0.0001), preoperative motor deficit (p = 0.0043), older age (p = 0.0113), and preoperative embolization (p = 0.0171) as risk factors for an immediate postoperative deficit, whereas DWI signal > 1 cm (p < 0.0001), tumor size (p < 0.0001), and older age (p = 0.0181) were risk factors for deficits lasting more than 3 months postoperatively. Multivariate analysis revealed a DWI signal > 1 cm to be the only significant risk factor for deficits at 3 months postoperatively (OR 32.42, 95% CI 3.3-320.1, p = 0.0002). Further, estimated blood loss (OR 1.4 per 100 ml increase, 95% CI 1.1-1.7, p < 0.0001), older age (OR 1.1 per year older, 95% CI 1.0-1.1, p = 0.0009), middle third location in the sagittal plane (OR 16.9, 95% CI 1.3-216.9, p = 0.0026), and preoperative peritumoral edema (OR 4.6, 95% CI 1.2-17.7, p = 0.0249) were significantly associated with a postoperative DWI signal > 1 cm.

CONCLUSIONS

A DWI signal > 1 cm is significantly associated with postoperative neurological deficits, both immediate and long-lasting. Greater estimated blood loss, older age, tumor location over the motor strip, and preoperative peritumoral edema increase the risk of having a postoperative DWI signal > 1 cm, reflective of perilesional ischemia. Most immediate postoperative deficits will improve over time. These data are valuable when preoperatively communicating with patients about the risks of surgery and when postoperatively discussing prognosis after a deficit occurs.

Endonasal endoscopic approach to the pterygopalatine and infratemporal fossae

The pterygopalatine fossa and infratemporal fossa are spaces located under the skull base, housing important neurovascular structures. Surgical access to these spaces is challenging because of their deep location and complex anatomy. Their surgical access has been classically carried out through multiple craniofacial approaches until the advent of endoscopic endonasal surgery at the end of the XX^th century. Our goal is to describe the transmaxillary-transsphenoidal-transpterygoid approach to the pterygopalatine and infratemporal fossae through endonasal endoscopic surgery based on anatomo-surgical dissection and an illustrative clinical case. We conclude that after careful radiologic evaluation of the feasibility of this technique, the endonasal endoscopic access to these spaces for tumor resection is efficient with reduced surgical morbidities. The endonasal approach is versatile and can be fashioned according to the nature and extent of the lesion.

A Prognostic Gene-Expression Signature and Risk Score for Meningioma Recurrence After Resection

BACKGROUND

Prognostic markers for meningioma are needed to risk-stratify patients and guide postoperative surveillance and adjuvant therapy.

OBJECTIVE

To identify a prognostic gene signature for meningioma recurrence and mortality after resection using targeted gene-expression analysis.

METHODS

Targeted gene-expression analysis was used to interrogate a discovery cohort of 96 meningiomas and an independent validation cohort of 56 meningiomas with comprehensive clinical follow-up data from separate institutions. Bioinformatic analysis was used to identify prognostic genes and generate a gene-signature risk score between 0 and 1 for local recurrence.

RESULTS

We identified a 36-gene signature of meningioma recurrence after resection that achieved an area under the curve of 0.86 in identifying tumors at risk for adverse clinical outcomes. The gene-signature risk score compared favorably to World Health Organization (WHO) grade in stratifying cases by local freedom from recurrence (LFFR, P < .001 vs .09, log-rank test), shorter time to failure (TTF, F-test, P < .0001), and overall survival (OS, P < .0001 vs .07) and was independently associated with worse LFFR (relative risk [RR] 1.56, 95% CI 1.30-1.90) and OS (RR 1.32, 95% CI 1.07-1.64), after adjusting for clinical covariates. When tested on an independent validation cohort, the gene-signature risk score remained associated with shorter TTF (F-test, P = .002), compared favorably to WHO grade in stratifying cases by OS (P = .003 vs P = .10), and was significantly associated with worse OS (RR 1.86, 95% CI 1.19-2.88) on multivariate analysis.

CONCLUSION

The prognostic meningioma gene-expression signature and risk score presented may be useful for identifying patients at risk for recurrence.

Consensus-based perioperative protocols during the COVID-19 pandemic

OBJECTIVE

During the COVID-19 pandemic, quaternary-care facilities continue to provide care for patients in need of urgent and emergent invasive procedures. Perioperative protocols are needed to streamline care for these patients notwithstanding capacity and resource constraints.

METHODS

A multidisciplinary panel was assembled at the University of California, San Francisco, with 26 leaders across 10 academic departments, including 7 department chairpersons, the chief medical officer, the chief operating officer, infection control officers, nursing leaders, and resident house staff champions. An epidemiologist, an ethicist, and a statistician were also consulted. A modified two-round, blinded Delphi method based on 18 agree/disagree statements was used to build consensus. Significant disagreement for each statement was tested using a one-sided exact binomial test against an expected outcome of 95% consensus using a significance threshold of p < 0.05. Final triage protocols were developed with unblinded group-level discussion.

RESULTS

Overall, 15 of 18 statements achieved consensus in the first round of the Delphi method; the 3 statements with significant disagreement (p < 0.01) were modified and iteratively resubmitted to the expert panel to achieve consensus. Consensus-based protocols were developed using unblinded multidisciplinary panel discussions. The final algorithms 1) quantified outbreak level, 2) triaged patients based on acuity, 3) provided a checklist for urgent/emergent invasive procedures, and 4) created a novel scoring system for the allocation of personal protective equipment. In particular, the authors modified the American College of Surgeons three-tiered triage system to incorporate more urgent cases, as are often encountered in neurosurgery and spine surgery.

CONCLUSIONS

Urgent and emergent invasive procedures need to be performed during the COVID-19 pandemic. The consensus-based protocols in this study may assist healthcare providers to optimize perioperative care during the pandemic.

Clinical characteristics and outcomes in elderly patients undergoing transsphenoidal surgery for nonfunctioning pituitary adenoma

OBJECTIVE

Life expectancy has increased over the past century, causing a shift in the demographic distribution toward older age groups. Elderly patients comprise up to 14% of all patients with pituitary tumors, with most lesions being nonfunctioning pituitary adenomas (NFPAs). Here, the authors evaluated demographics, outcomes, and postoperative complications between nonelderly adult and elderly NFPA patients.

METHODS

A retrospective review of 908 patients undergoing transsphenoidal surgery (TSS) for NFPA at a single institution from 2007 to 2019 was conducted. Clinical and surgical outcomes and postoperative complications were compared between nonelderly adult (age ≥ 18 and ≤ 65 years) and elderly patients (age > 65 years).

RESULTS

There were 614 and 294 patients in the nonelderly and elderly groups, respectively. Both groups were similar in sex (57.3% vs 60.5% males; p = 0.4), tumor size (2.56 vs 2.46 cm; p = 0.2), and cavernous sinus invasion (35.8% vs 33.7%; p = 0.6). Regarding postoperative outcomes, length of stay (1 vs 2 days; p = 0.5), extent of resection (59.8% vs 64.8% gross-total resection; p = 0.2), CSF leak requiring surgical revision (4.3% vs 1.4%; p = 0.06), 30-day readmission (8.1% vs 7.3%; p = 0.7), infection (3.1% vs 2.0%; p = 0.5), and new hypopituitarism (13.9% vs 12.0%; p = 0.3) were similar between both groups. Elderly patients were less likely to receive adjuvant radiation (8.7% vs 16.3%; p = 0.009), undergo future reoperation (3.8% vs 9.5%; p = 0.003), and experience postoperative diabetes insipidus (DI) (3.7% vs 9.4%; p = 0.002), and more likely to have postoperative hyponatremia (26.7% vs 16.4%; p < 0.001) and new cranial nerve deficit (1.9% vs 0.0%; p = 0.01). Subanalysis of elderly patients showed that patients with higher Charlson Comorbidity Index scores had comparable outcomes other than higher DI rates (8.1% vs 0.0%; p = 0.006). Elderly patients’ postoperative sodium peaked and troughed on postoperative day 3 (POD3) (mean 138.7 mEq/L) and POD9 (mean 130.8 mEq/L), respectively, compared with nonelderly patients (peak POD2: mean 139.9 mEq/L; trough POD8: mean 131.3 mEq/L).

CONCLUSIONS

The authors’ analysis revealed that TSS for NFPA in elderly patients is safe with low complication rates. In this cohort, more elderly patients experienced postoperative hyponatremia, while more nonelderly patients experienced postoperative DI. These findings, combined with the observation of higher DI in patients with more comorbidities and elderly patients experiencing later peaks and troughs in serum sodium, suggest age-related differences in sodium regulation after NFPA resection. The authors hope that their results will help guide discussions with elderly patients regarding risks and outcomes of TSS.

Residual Tumor Volume and Location Predict Progression After Primary Subtotal Resection of Sporadic Vestibular Schwannomas: A Retrospective Volumetric Study

BACKGROUND

Preservation of functional integrity during vestibular schwannoma surgery has become critical in the era of patient-centric medical decision-making. Subtotal tumor removal is often necessary when dense adhesions between the tumor and critical structures are present. However, it is unclear what the rate of tumor control is after subtotal resection (STR) and what factors are associated with recurrence.

OBJECTIVE

To determine the rate of residual tumor growth after STR and identify clinical and radiographic predictors of tumor progression.

METHODS

A single-institution retrospective study was performed on all sporadic vestibular schwannomas that underwent surgical resection between January 1, 2002 and December 31, 2015. Clinical charts, pathology, radiology, and operative reports were reviewed. Volumetric analysis was performed on all pre- and postoperative MR imaging. Univariate and multivariate logistic regression was performed to identify predictors of the primary endpoint of tumor progression. Kaplan-Meier analysis was performed to compare progression free survival between 2 groups of residual tumor volumes and location.

RESULTS

In this cohort of 66 patients who underwent primary STR, 30% had documented progression within a median follow up period of 3.1 yr. Greater residual tumor volume (OR 2.0 [1.1-4.0]) and residual disease within the internal auditory canal (OR 3.7 [1.0-13.4]) predicted progression on multivariate analysis.

CONCLUSION

These longitudinal data provide insight into the behavior of residual tumor, helping clinicians to determine if and when STR is an acceptable surgical strategy and to anchor expectations during shared medical decision-making consultation with patients.