Magnetic Resonance-Guided Laser Interstitial Thermal Therapy for Management of Low-Grade Gliomas and Radiation Necrosis: A Single-Institution Case Series

Background: Laser interstitial thermal therapy (LITT) has emerged as a minimally invasive treatment modality for ablation of low-grade glioma (LGG) and radiation necrosis (RN). Objective: To evaluate the efficacy, safety, and survival outcomes of patients with radiographically presumed recurrent or newly diagnosed LGG and RN treated with LITT. Methods: The neuro-oncological database of a quaternary center was reviewed for all patients who underwent LITT for management of LGG between 1 January 2013 and 31 December 2020. Clinical data including demographics, lesion characteristics, and clinical and radiographic outcomes were collected. Kaplan-Meier analyses comprised overall survival (OS) and progression-free survival (PFS). Results: Nine patients (7 men, 2 women; mean [SD] age 50 [16] years) were included. Patients underwent LITT at a mean (SD) of 11.6 (8.5) years after diagnosis. Two (22%) patients had new lesions on radiographic imaging without prior treatment. In the other 7 patients, all (78%) had surgical resection, 6 (67%) had intensity-modulated radiation therapy and chemotherapy, respectively, and 4 (44%) had stereotactic radiosurgery. Two (22%) patients had lesions that were wild-type IDH1 status. Volumetric assessment of preoperative T1-weighted contrast-enhancing and T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences yielded mean (SD) lesion volumes of 4.1 (6.5) cm(3) and 26.7 (27.9) cm(3), respectively. Three (33%) patients had evidence of radiographic progression after LITT. The pooled median (IQR) PFS for the cohort was 52 (56) months, median (IQR) OS after diagnosis was 183 (72) months, and median (IQR) OS after LITT was 52 (60) months. At the time of the study, 2 (22%) patients were deceased. Conclusions: LITT is a safe and effective treatment option for management of LGG and RN, however, there may be increased risk of permanent complications with treatment of deep-seated subcortical lesions

Multiomic analyses implicate a neurodevelopmental program in the pathogenesis of cerebral arachnoid cysts

Cerebral arachnoid cysts (ACs) are one of the most common and poorly understood types of developmental brain lesion. To begin to elucidate AC pathogenesis, we performed an integrated analysis of 617 patient-parent (trio) exomes, 152,898 human brain and mouse meningeal single-cell RNA sequencing transcriptomes and natural language processing data of patient medical records. We found that damaging de novo variants (DNVs) were highly enriched in patients with ACs compared with healthy individuals (P = 1.57 × 10-33). Seven genes harbored an exome-wide significant DNV burden. AC-associated genes were enriched for chromatin modifiers and converged in midgestational transcription networks essential for neural and meningeal development. Unsupervised clustering of patient phenotypes identified four AC subtypes and clinical severity correlated with the presence of a damaging DNV. These data provide insights into the coordinated regulation of brain and meningeal development and implicate epigenomic dysregulation due to DNVs in AC pathogenesis. Our results provide a preliminary indication that, in the appropriate clinical context, ACs may be considered radiographic harbingers of neurodevelopmental pathology warranting genetic testing and neurobehavioral follow-up. These data highlight the utility of a systems-level, multiomics approach to elucidate sporadic structural brain disease

Binder Ring Bypass: V4-V4 Vertebral Artery Transection, Rerouting, and Reanastomosis for Treatment of a Compressive Dolichoectatic Vertebral Artery: 2-Dimensional Operative Video

Vertebrobasilar dolichoectasia may present with compression on the brainstem or surrounding cranial nerves. The surgical management for this pathology may include microvascular decompression, sling-based macrovascular decompression, or, as presented here, a novel rerouting of the artery using reanastomosis bypass. This unique video demonstrates the pathology of this case and why it is not amenable to typical macrovascular decompression, as well as the execution of the novel binder ring bypass, which includes transecting the offending vessel, rerouting it around the cranial nerves, and reanastomosis.1 A man in his early 70s who presented with symptomatic compression underwent a left retrosigmoid craniotomy to expose the distal tortuous vertebral artery, which displaced the left cranial nerve VII/VIII complex in the cerebellopontine angle. This segment was trapped with temporary aneurysm clips, transected, and the ends of the artery were then mobilized away from the nerves. The ends were brought back together in a comfortable position lateral to the cranial nerves. A V4-V4 end-to-end reanastomosis (V4 [E-Ec*] V4 bypass) was performed with a fourth-generation bypass technique, using intraluminal suturing for the deep suture line. The patient enjoyed complete symptomatic relief thereafter, with normal hearing. The relief of symptoms is believed to be attributable to cranial nerve decompression rather than to brainstem decompression. The patient provided written informed consent for treatment. Used with permission from Barrow Neurological Institute

The Binder Ring Bypass: Transection, Rerouting, and Reanastomosis as an Alternative to Macrovascular Decompression of a Dolichoectatic Vertebral Artery

BACKGROUND: In cases of extreme vertebrobasilar dolichoectasia, padding the cranial nerves (CNs) (microvascular decompression [MVD]) and clip-assisted sling transposition of the tortuous artery (macrovascular decompression [MaVD]) may be ineffective because the sling does not reduce the redundancy. Transposition may not decompress the nerves or may kink the artery. An alternative solution is needed. OBJECTIVE: To introduce the binder ring bypass as a novel solution to this unusual macrovascular compression problem. METHODS: The binder ring denotes the opening and closing of the offending vascular loop with standard bypass techniques with the artery transected, rerouted lateral to the CNs, and reanastomosed. An example case study is presented for a 72-year-old man whose severe vertebral artery tortuosity could not be relieved by MVD or MaVD. His pathology was exposed with an extended retrosigmoid craniotomy, the V4 segment was transected, the free ends were mobilized lateral to CN VII/VIII, and an end-to-end reanastomosis was performed with intraluminal suturing. RESULTS: The example binder ring bypass was patent angiographically, and the patient experienced immediate and lasting symptom relief without complications. CONCLUSION: The binder ring bypass applies standard bypass techniques to macrovascular compression but represents a significant escalation in technical challenges relative to traditional techniques. Patient tolerance to temporary arterial occlusion during reanastomosis depends on the location of the compressive arterial loop and the anatomy of collateral circulation. The binder ring bypass should be used as a last resort after medical therapy and MaVD techniques fail and performed only by neurosurgeons with advanced bypass skills

Thoracic laminectomy and midline myelotomy for resection of a spinal ependymoma

Spinal cord ependymomas comprise 25% of all intramedullary tumors and are typically treated with resection. A man in his mid-60s presented with imbalance and sensory deficits in both lower extremities, and a spinal thoracic intramedullary ependymoma spanning the levels T2 and T3 was diagnosed. After a laminectomy was performed, the tumor was microsurgically resected, and the patient demonstrated no neurological deficits on postoperative examination. Subsequent MRI showed complete resection of the tumor. This video showcases a thoracic intramedullary ependymoma resected using careful microdissection into the median raphe as a safe entry zone to preserve neurological function

Trends in medical device company payments in neurosurgery: a nationwide, multidatabase, geospatial analysis

OBJECTIVE: Industry partnerships help advance the field of neurosurgery. Given the nature of the field and its close relationship with innovation, neurosurgeons frequently partner with the medical device industry to advance technology and improve outcomes. However, this can create important ethical concerns for patients. In this paper, the authors sought to comprehensively study how physician payments from medical device companies have changed and what geographic parameters influence the trends observed over the years. METHODS: The authors queried and merged several large databases, including Medicare and Medicaid provider usage data and databases from the Open Payments Program, National Plan and Provider Enumeration System, and US Census Bureau. Geospatial analysis was performed using Moran\u27s I and II clustering. Univariate and multivariable analyses were performed using the Mann-Whitney U-test and geospatially weighted multivariable regression for hot spot and cold spot membership. RESULTS: Data for 952 counties across the continental United States were analyzed. Ninety-seven counties constituted geographic hot spots. These hot spots were primarily concentrated in Florida, the New York-Pennsylvania region, central Colorado, and southwestern United States. Independent predictors of hot spot membership included greater unemployment rates, the percentage of White patients, the presence of mobile homes, and the percentage of county Hispanic and Black populations. Company-based differences were examined. The vast majority of Medtronic\u27s payments were in the form of royalties and licensing (86.6%). Royalties and licensing accounted for the majority of payments for DePuy (69.4%), Globus Medical (62%), and NuVasive (77.1%). In contrast, other companies, such as Boston Scientific, opted to pay physicians in the form of ownership and investment interests (42.1%). The impact of the COVID-19 pandemic was also assessed. During the onset of the pandemic in 2020, physician payments fell or remained the same across all regions with the exception of the South Atlantic region. However, it was observed that nearly all regions rebounded, with stark elevations in physician payments immediately in 2021. CONCLUSIONS: This analysis demonstrates that there are national hot spots and cold spots of physician payments, and offers some social, economic, and company-dependent predictors that may influence the magnitude of payments. Further analysis is needed to better understand this clinical-commercial partnership in healthcare, specifically within neurosurgical practice

Differentiating radiation necrosis from tumor recurrence: a systematic review and diagnostic meta-analysis comparing imaging modalities

PURPSOSE: Cerebral radiation necrosis (RN) is often a delayed phenomenon occurring several months to years after the completion of radiation treatment. Differentiating RN from tumor recurrence presents a diagnostic challenge on standard MRI. To date, no evidence-based guidelines exist regarding imaging modalities best suited for this purpose. We aim to review the current literature and perform a diagnostic meta-analysis comparing various imaging modalities that have been studied to differentiate tumor recurrence and RN. METHODS: A systematic search adherent to PRISMA guidelines was performed using Scopus, PubMed/MEDLINE, and Embase. Pooled sensitivities and specificities were determined using a random-effects or fixed-effects proportional meta-analysis based on heterogeneity. Using diagnostic odds ratios, a diagnostic frequentist random-effects network meta-analysis was performed, and studies were ranked using P-score hierarchical ranking. RESULTS: The analysis included 127 studies with a total of 220 imaging datasets, including the following imaging modalities: MRI (n = 10), MR Spectroscopy (MRS) (n = 28), dynamic contrast-enhanced MRI (n = 7), dynamic susceptibility contrast MRI (n = 36), MR arterial spin labeling (n = 5), diffusion-weighted imaging (n = 13), diffusion tensor imaging (DTI) (n = 2), PET (n = 89), and single photon emission computed tomography (SPECT) (n = 30). MRS had the highest pooled sensitivity (90.7%). DTI had the highest pooled specificity (90.5%). Our hierarchical ranking ranked SPECT and MRS as most preferable, and MRI was ranked as least preferable. CONCLUSION: These findings suggest SPECT and MRS carry greater utility than standard MRI in distinguishing RN from tumor recurrence