Resection of a Neuroenteric Cyst Using a Far Lateral Approach.

This operative video highlights a rare case of a neuroenteric cyst at the ventral craniocervical junction. The case involved a 30-year-old man who initially presented 13 years earlier with acute onset of headache and visual changes. At that time, he was found to have a small, enhancing ventral intradural extramedullary mass at the rostral aspect of C1 thought to be a meningioma. The lesion was managed conservatively, and surveillance imaging tracked its slow progressive enlargement to a size of 1.4 cm ( Fig. 1A, B ). Although he remained asymptomatic, nonurgent elective resection was recommended because of his age and mass progression. The patient underwent a left far lateral approach to the craniocervical junction for resection of the mass. This involved dissection of the suboccipital musculature to expose the C1 transverse process in the suboccipital triangle and ultimately the vertebral artery. After a small craniectomy and C1 hemilaminectomy, the dura was opened and a cystic lesion encountered ( Fig. 2 ). The cystic contents were debulked and the capsule resected. Histopathologic examination revealed abundant goblet cells consistent with a neuroenteric cyst. Dural closure was bolstered with fascia lata and autologous fat graft. Postoperative magnetic resonance imaging (MRI) was consistent with gross total resection ( Fig. 1C, D ). The patient tolerated the procedure well with no new postoperative neurological deficits and was discharged home on postoperative day 2. On completing a 3-day decadron taper, he developed steroid-responsive symptoms consistent with aseptic meningitis, possibly related to cerebrospinal fluid contamination with the cyst contents during resection. The link to the video can be found at: https://youtu.be/SskETPe5PXQ .

Obesity Is Not Associated With Postoperative Complications After Vestibular Schwannoma Surgery in a Large Single Institution Series.

OBJECTIVE: Determine whether elevated body mass index (BMI) is associated with postoperative complications after vestibular schwannoma (VS) surgery. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. PATIENTS: Two hundred six patients undergoing surgery for VS between 2010 and 2017, grouped into obese and nonobese patients. INTERVENTION: Surgery for VS resection. MAIN OUTCOME MEASURES: Postoperative facial nerve outcomes, length of hospital stay, presence of postoperative cerebrospinal fluid leak, 30-day readmission, return to the operating room, wound complications, cardiovascular and thromboembolic complications. RESULTS: After excluding 1 patient for missing BMI, our cohort included 205 patients. Seventy-nine patients (38.5%) were obese (mean BMI 36.2 kg/m, range 30-55.1) and the remaining 126 (61.5%) were nonobese (mean BMI 25.0, range 18.8-29.8 kg/m). Compared with nonobese patients, obesity was not associated with postoperative cerebrospinal fluid leak (OR 1.1, 95% CI 0.93-1.1), length of hospital stay (OR 0.98, 95% CI 0.65-1.47), 30-day readmission rates (1.04, 95% CI 0.95-1.14), return to operating room (OR 1.05, 95% CI 0.98-1.11), or other wound-related complications (OR 0.99, 95% CI 0.94-1.04). CONCLUSION: In this cohort, elevated BMI was not associated with an increased risk for postoperative complications after VS surgery. Our findings may mitigate concerns associated with surgical management of VS in obese patients.

Cerebrospinal Fluid Leak Rate after Vestibular Schwannoma Surgery via Middle Cranial Fossa Approach.

Objective Evaluate the cerebrospinal fluid (CSF) leak rate after the middle cranial fossa (MCF) approach to vestibular schwannoma (VS) resection. Design Retrospective case series. Setting Quaternary referral academic center. Participants Of 161 patients undergoing the MCF approach for a variety of skull base pathologies, 66 patients underwent this approach for VS resection between 2007 and 2017. Main Outcome Measure Postoperative CSF leak rate. Results There were two instances of postoperative CSF leak (3.0%). Age, gender, and BMI were not significantly associated with CSF leak. In the two cases with CSF leakage, tumors were isolated to the internal auditory canal (IAC) and both underwent gross total resection. Both CSF leaks were successfully treated with lumbar drain diversion. For the 64 cases that did not have a CSF leak, 51 were isolated to the IAC, 1 was located only in the cerebellopontine angle (CPA), and 12 were located in both the IAC and CPA. 62 patients underwent gross total resection and 2 underwent near-total resection. Mean maximal tumor diameter in the CSF leak group was 4.5 mm (range: 3-6 mm) versus 10.2 mm (range: 3-19 mm) in patients with no CSF leak ( p = 0.03). Conclusions The MCF approach for VS resection is a valuable technique that allows for hearing preservation and total tumor resection and can be performed with a low CSF leakage rate. This rate of CSF leak is less than the reported rates in the literature in regard to both translabyrinthine and retrosigmoid approaches.

Application of Ultrasonic Bone Aspirator for Decompression of the Internal Auditory Canal via the Middle Cranial Fossa Approach.

OBJECTIVE: Evaluate the safety and efficacy of the ultrasonic bone aspirator (UBA) during middle cranial fossa (MCF) approach to vestibular schwannoma (VS). STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. PATIENTS: Charts of 192 consecutive VS patients over 18 years of age were reviewed to identify 65 patients who underwent MCF approach to VS resection between 2006 and 2017. A combination of UBA and high-speed drill (HSD) was used to decompress the internal auditory canal (IAC) in 25 patients and HSD alone was used in the other 40 patients. INTERVENTION(S): Use of UBA during vestibular schwannoma surgery via MCF approach for decompression of the IAC. MAIN OUTCOME MEASURE(S): Postoperative facial nerve outcomes assessed by the House-Brackmann (HB) facial nerve grading scale. Rates of gross total resection (GTR) and cerebrospinal fluid (CSF) leak. RESULTS: There were no significant differences in postoperative facial nerve function, in rate of GTR of tumor, or in rate of CSF leak. In the UBA group 24/25 (96%) had postoperative HB grade I-II compared with 36/40 (90%) in the HSD group (p-value = 0.66). GTR was achieved in 25/25 (100%) in the UBA group compared with 38/40 (95%) in the HSD group (p-value = 1). In the UBA group, there were 0/25 (0%) cases of CSF leak compared with 1/40 (2.5%) in the HSD group (p-value = 1). CONCLUSIONS: UBA use is a safe and effective alternative or adjunct to HSD during MCF approach to expose the IAC contents. This surgical tool allows for bone removal with low risk of injury to adjacent structures.

Middle Fossa Approach for Resection of Vestibular Schwannomas: A Decade of Experience.

BACKGROUND: The middle cranial fossa (MCF) approach is a challenging surgical technique for the resection of small and intermediate sized, primarily intracanalicular, vestibular schwannomas (VS), with the goal of hearing preservation (HP). OBJECTIVE: To describe a decade-long, single institutional experience with the MCF approach for resection of VS. METHODS: This is a retrospective cohort study of 63 patients who underwent the MCF approach for resection of VS from 2006 to 2016. Audiometric data included pure-tone average (PTA), low-tone pure-tone average (LtPTA), word recognition score, and American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing classification at presentation and follow-up. Patients with postoperative serviceable (AAO-HNS class A-B) and/or useful (AAO-HNS class A-C) hearing were compared to those without HP. Facial nerve function was assessed using the House-Brackmann scale. RESULTS: The mean age and duration of follow-up were 50 ± 13 yr and 21 ± 21 mo, respectively. The mean tumor size was 10 ± 4 mm. The serviceable and usable HP rates were 54% and 50%, respectively. Some residual hearing was preserved in 71% of patients. Large tumor size (P = .05), volume (P = .03), and extrameatal tumor extension (P = .03) were associated with poor audiometric outcomes. The presence of a fundal fluid cap (P = .01) was a favorable finding. At definitive testing, LtPTA was significantly better preserved than traditional PTA (P = .01). Facial nerve outcomes, tumor control rates, and durability of audiometric outcomes were excellent. 47% of patients pursued aural rehabilitation. CONCLUSION: In our series, the MCF approach for VS provided excellent rates of tumor and facial nerve function, with durable serviceable HP.

Early disruptions of the blood-brain barrier may contribute to exacerbated neuronal damage and prolonged functional recovery following stroke in aged rats.

We examined the effects of age on stroke progression and outcome in order to explore the association between blood-brain barrier (BBB) disruption, neuronal damage, and functional recovery. Using middle cerebral artery occlusion (MCAO), young (3 months) and aged (18 months) rats were assessed for BBB disruption at 20min post-MCAO, and 24h post-MCAO with tissue plasminogen activator induced reperfusion at 120min. Results showed that BBB disruptions in aged rats occurred early and increased nearly two-fold at both the 20min and 24h time points when compared to young animals. Neuronal damage in aged rats was increased two-fold as compared to young rats at 24h, while no neuronal damage was observed at 20min. Young and aged rats exhibited neurological deficits when compared to sham-controls out to 14 days following MCAO and reperfusion; however, aged rats exhibited more severe onset of deficits and prolonged recovery. Results indicate that aged rats suffer larger infarctions, reduced functional recovery and increased BBB disruption preceding observable neuronal injury.

Selective MCA occlusion: a precise embolic stroke model.

The present study describes a method for improving the precision and accuracy of clot placement within the middle cerebral artery (MCA) of rats, utilizing a micro-catheter and laser Doppler flowmetry. This technique reduces the size of clot needed to achieve stable occlusion with no failed embolizations and a low percentage of early recanalizations. Infarctions were consistent in both size and distribution within the MCA perfusion territory. Selective embolization in aged animals (n = 10) resulted in substantially larger infarctions than those seen in aged animals (n = 10) following non-selective embolization (P < 0.05), or young animals (n = 10) subjected to filamentous occlusion (P < 0.001). Clots were localized to the MCA by direct examination at 0, 60 and 120 min post-embolization (n = 14). All aged animals surviving 24h exhibited moderate to severe functional deficits, with selectively occluded animals having a higher mean score on the modified neurologic severity scale (P = 0.002). This model provides a highly reproducible method for embolization of the MCA and reliable reperfusion with rt-PA.

Influence of age on stroke outcome following transient focal ischemia.

OBJECT: More than 100 clinical trials based on animal models have failed to identify a clinically effective neuroprotectant for stroke. Current models of stroke do not account adequately for aging nor do they incorporate the use of female animals. The authors evaluated the pathological and physiological differences in stroke in young, adult, and elderly female rats. METHODS: Three groups of female Sprague-Dawley rats were studied. Nine rats were divided into three groups: young (3 months); adult (9 months); and elderly (18 months). Intraluminal filament occlusion was performed for 120 minutes while cerebral blood flow was monitored. Physiological parameters were assessed. Infarction volumes were quantified at 24 hours. The mean arterial pressure increased in the young animals (103 +/- 3.51 mm Hg; p < 0.001) during occlusion and decreased in the elderly group (65.56 +/- 3.03 mm Hg; p < 0.01). Cortical and striatal infarction volumes in the elderly animals were substantially larger (p < 0.05). Young animals exhibited a lesser decrement in cerebral blood flow (p < 0.05) during ischemia. CONCLUSIONS: This study reinforces the importance of using older animals for the researching and treatment of stroke. Elderly animals show differences in response mechanisms, ischemic consequences, and histological changes. These differences may partially explain the current lack of success involved in using young-animal models to predict the clinical efficacy of neuroprotective agents.