Rinaldo, Lorenzo

Aneurysms associated with a vertebrobasilar fenestration are rare lesions and can grow to a giant size, presenting significant therapeutic challenges. Endovascular treatment of these aneurysms has traditionally been with coiling; however, flow diverter placement within the fenestration arms has recently proven to be a viable treatment strategy. The authors present a case of a giant vertebrobasilar fenestration aneurysm in a patient presenting with a cranial nerve VI palsy. The lesion was treated by using a combination of flow diverter placement and vertebral artery sacrifice. The nuances of flow diversion therapy for these aneurysms and the management of intra- and postoperative complications are discussed. The video can be found here: https://stream.cadmore.media/r10.3171/2022.7.FOCVID2256

Introduction: Digital subtraction angiography (DSA) is currently the gold standard for evaluation of moyamoya disease (MMD) and is the basis for several grading systems. Non-invasive modalities such as MRA are also used in assessment of MMD. Accurate implementation of these staging systems for use with MRA would imply a less-invasive method of MMD monitoring. Methods: This was a single-center retrospective study that compared MRA to reference DSA studies in determining MMD severity using Berlin and modified Suzuki (mSG) grading systems A single reviewer assigned modified Suzuki and Berlin grades to all included hemispheres on both MRA and DSA. The mean difference between MRA and DSA grades for each DSA reference grade was determined utilizing both grading systems. The distribution of scores was also compared between MRA and DSA using both grading systems. Results: A total of 166 cerebral hemispheres in 90 patients were included: The mean age at MMD diagnosis was 34.8 years (standard deviation [SD] = 14.2), and fifty-three patients (63.9%) were male. Mean MRA grades were significantly lower than DSA reference grades 3 and 4 utilizing the mSG system (p = <0.0001 in both cases); A similar pattern was observed for Berlin grades 2 and 3 (p = <0.0001, Table 1 ). The distribution of modified Suzuki grades on MRA was skewed toward relatively lower grades as compared to DSA (p = <0.0001): This pattern was also true for Berlin grades as well (p = <0.0001, Table 2 ). Conclusions: DSA is essential in the evaluation of MMD, as MRA is shown to underestimate disease stage, with a greater degree of underestimation in more severe disease. We suggest DSA be performed in order to aid in appropriate treatment planning.

Abstract BACKGROUND Open surgery has traditionally been preferred for the management of bifurcation middle cerebral artery (MCA) aneurysms. Flow diverting stents present a novel endovascular strategy for aneurysm treatment. OBJECTIVE To add to the limited literature describing the outcomes and complications in the use of flow diverters for the treatment of these complex aneurysms. METHODS This is a multicenter retrospective review of MCA bifurcation aneurysms undergoing flow diversion. We assessed post-treatment radiological outcomes and both thromboembolic and hemorrhagic complications. RESULTS We reviewed the outcomes of 54 aneurysms treated with flow diversion. Four (7.4%) of the aneurysms had a history of rupture (3 remote and 1 acute). Fourteen (25.9%) of the aneurysms already underwent either open surgery or coiling prior to flow diversion. A total of 36 out of the 45 aneurysms (80%) with available follow-up data had adequate aneurysm occlusion with a median follow-up time of 12 mo. There were no hemorrhagic complications but 16.7% (9/54) had thromboembolic complications. CONCLUSION Flow diverting stents may be a viable option for the endovascular treatment of complex bifurcation MCA aneurysms. However, compared to published series on the open surgical treatment of this subset of aneurysms, flow diversion has inferior outcomes and are associated with a higher rate of complications.

OBJECTIVE Symptomatic nonsaccular vertebrobasilar aneurysms (NSVBAs) are associated with high rates of aneurysm-related death. Anecdotal evidence suggests that brainstem infarction may be a harbinger of aneurysm rupture. The authors aimed to investigate the association between brainstem infarction and subsequent NSVBA rupture. METHODS The clinical records and radiographic imaging studies of patients presenting to the authors’ institution between 1996 and 2019 for evaluation and management of an NSVBA were retrospectively reviewed to determine the effect of perforating artery infarction on the natural history of NSVBAs. Kaplan-Meier curves for patients with and patients without perforator infarction were constructed, and predictors of aneurysm rupture were identified using a multivariate Cox proportional hazards model. RESULTS There were 98 patients with 591.3 person-years of follow-up who met the inclusion criteria for analysis. There were 20 patients who experienced perforator infarction during follow-up. Ten patients (10.2%) experienced aneurysm rupture during follow-up and 26 patients (26.5%) died due to aneurysm-related complications, with annual rates of rupture and aneurysm-related death of 1.7% and 4.4%, respectively. Five patients with a perforator infarction later experienced aneurysm rupture, with a median time between infarction and rupture of 3 months (range 0–35 months). On multivariate analysis, the presence of intraaneurysmal thrombus (risk ratio [RR] 4.01, 95% confidence interval [CI] 1.12–14.44, p = 0.033) and perforator infarction (RR 6.37, 95% CI 1.07–37.95, p = 0.042) were independently associated with risk of aneurysm rupture. CONCLUSIONS NSVBAs continue to be extremely challenging clinical entities with a poor prognosis. These results suggest that brainstem infarction due to perforating artery occlusion may be a harbinger of near-term aneurysm rupture.

Abstract Trigeminal nerve schwannomas (TNSs) are rare lesions that typically present with symptoms of trigeminal neuropathy or other cranial nerve palsies. These lesions classically have a dumbbell shape, with an anterior component within Meckel's cave and posterior component extending into the posterior fossa through the porus trigeminus. Surgical resection of TNSs can often be achieved via an extradural subtemporal approach to Meckel's cave without an anterior petrousectomy, even for tumors with a significant posterior fossa component, as the tumor often erodes a portion of the petrous apex. 1 We present the case of a 53-yr-old female presenting to our institution with complete trigeminal neuropathy secondary to a right-sided, previously resected and radiated TNS. Serial imaging demonstrated an interval growth of significant residual tumor despite multiple adjuvant therapies, and, thus, the patient was recommended to undergo additional surgical resection. The lesion was approached through a right-sided subtemporal approach to Meckel's cave, 2 with a plan to utilize an anterior petrousectomy only if difficulty resecting the posterior fossa component of the tumor was encountered. Intraoperatively, the posterior fossa component was found to be densely adherent to the adjacent brainstem, likely secondary to prior surgery and radiation therapy, and, thus, an anterior petrousectomy was performed. Postoperatively, the patient had stable trigeminal neuropathy without any new neurological deficits and a magnetic resonance imaging (MRI) confirmed a gross total resection. In the accompanying video, we hope to demonstrate the steps and nuances of both the subtemporal approach to accessing Meckel's cave and anterior petrousectomy when employed for the resection of TNSs. The patient in question provided formal consent for the making of this video.