Faculty Bibliography

BACKGROUND AND PURPOSE/OBJECTIVE:Skull base tumors are commonly supplied by dural branches of the meningohypophyseal and inferolateral trunks. Embolization through these arteries is often avoided due to technical challenges and inherent risks; however, successful embolization can be a valuable surgical adjunct. We aimed to review the success and complications in our series of tumor embolizations through the meningohypophyseal and inferolateral trunks. MATERIALS AND METHODS/METHODS:We performed a retrospective review of patients with tumor treated with preoperative embolization at our institution between 2010 and 2020. We reviewed the following data: patients' demographics, tumor characteristics, endovascular embolization variables, and surgical results including estimated blood loss, the need for transfusion, and operative time. RESULTS:= 4) trunk. In this group of patients, on average, 79% of tumors were embolized. No mortality or morbidity from the embolization procedure was observed in this subgroup of patients. The average estimated blood loss in the operation was 395 mL (range, 200-750 mL). None of the patients required a transfusion, and the average operative time was 7.3 hours. CONCLUSIONS:Some skull base tumors necessitate embolization through ICA branches such as the meningohypophyseal and inferolateral trunks. Our series demonstrates that an effective and safe embolization may be performed through these routes.

BACKGROUND:Previous studies suggest that the mechanisms and outcomes in COVID-19-associated stroke differ from those with non-COVID-19 strokes, but there is limited comparative evidence focusing on these populations. Therefore, we aimed to determine if a significant association exists between COVID-19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors. METHODS:A cross-sectional, international multicenter retrospective study of consecutively admitted COVID-19 patients with concomitant acute LVO, compared to a control group without COVID-19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable adjusted analysis was conducted. RESULTS:In this cohort of 697 patients with acute LVO, 302 had COVID-19 while 395 patients did not. There was a significant difference (p<0.001) in the mean age (in years) and gender of patients, with younger patients and more males in the COVID-19 group. In terms of favorable revascularization (mTICI 3), COVID-19 was associated with lower odds of complete revascularization [OR=0.33; 95% CI=0.23-0.48; p<0.001], which persisted on multivariable modelling with adjustment for other predictors [aOR=0.30; 95% CI=0.12-0.77; p=0.012]. Moreover, endovascular complications, in-hospital mortality, and length of hospital stay were significantly higher among COVID-19 patients (p<0.001). CONCLUSION/CONCLUSIONS:COVID-19 was an independent predictor of incomplete revascularization and poor functional outcome in patients with stroke due to LVO. Furthermore, COVID-19 patients with LVO were more often younger and suffered higher morbidity/mortality rates.

BACKGROUND:Moyamoya disease may present with either hemorrhagic or ischemic strokes. Surgical bypass has previously demonstrated superiority when compared to natural history and medical treatment alone. The best bypass option (direct vs. indirect), however, remains controversial in regard to adult ischemic symptomatic moyamoya disease. Multiple studies have demonstrated clinical as well as angiographic effectiveness of direct bypass in adult hemorrhagic moyamoya disease. In particular, there are limited data regarding strategies in the setting of failed indirect bypass with recurrent hemorrhagic strokes. Here, we describe a salvage procedure. METHODS:We describe a case of a 52-year-old man who presented with hemorrhagic moyamoya disease and failed previous bilateral encephaloduroarteriosynangiosis (EDAS) procedures at an outside institution. On a 3-year follow-up diagnostic cerebral angiogram, no synangiosis was noted on the right side and only minimal synangiosis was present on the left. The left hemisphere was significant for a left parietal hypoperfusion state. We performed a salvage left proximal superficial temporal artery to distal parietal M4 middle cerebral artery bypass using the descending branch of the lateral circumflex artery as an interposition graft with preservation of the existing EDAS sites. RESULTS:The patient underwent the procedure successfully and recovered well with resolution of headaches and no further strokes or hemorrhages on the 1-year follow-up magnetic resonance imaging of the brain. CONCLUSIONS:This case presents the use of a salvage direct bypass technique for recurrent symptomatic hemorrhagic moyamoya disease after failed EDAS. The strategy, approach, and technical nuances of this unique case have implications for revascularization options.

BACKGROUND:The optimal endovascular strategy for reperfusing distal medium-vessel occlusions (DMVO) remains unknown. This study evaluates angiographic and clinical outcomes of thrombectomy strategies in DMVO stroke of the posterior circulation. METHODS:TOPMOST (Treatment for Primary Medium Vessel Occlusion Stroke) is an international, retrospective, multicenter, observational registry of patients treated for DMVO between January 2014 and June 2020. This study analyzed endovascularly treated isolated primary DMVO of the posterior cerebral artery in the P2 and P3 segment. Technical feasibility was evaluated with the first-pass effect defined as a modified Thrombolysis in Cerebral Infarction Scale score of 3. Rates of early neurological improvement and functional modified Rankin Scale scores at 90 days were compared. Safety was assessed by the occurrence of symptomatic intracranial hemorrhage and intervention-related serious adverse events. RESULTS:<0.025). Symptomatic intracranial hemorrhage occurred in 2.8% (4) of all cases. CONCLUSIONS:Both first-pass aspiration and stent retriever thrombectomy for primary isolated posterior circulation DMVO seem to be safe and technically feasible leading to similar favorable rates of angiographic and clinical outcome.

BACKGROUND:The mechanisms and outcomes in coronavirus disease (COVID-19)-associated stroke are unique from those of non-COVID-19 stroke. OBJECTIVE:To describe the efficacy and outcomes of acute revascularization of large vessel occlusion (LVO) in the setting of COVID-19 in an international cohort. METHODS:We conducted an international multicenter retrospective study of consecutively admitted patients with COVID-19 with concomitant acute LVO across 50 comprehensive stroke centers. Our control group constituted historical controls of patients presenting with LVO and receiving a mechanical thrombectomy between January 2018 and December 2020. RESULTS:The total cohort was 575 patients with acute LVO; 194 patients had COVID-19 while 381 patients did not. Patients in the COVID-19 group were younger (62.5 vs 71.2; P < .001) and lacked vascular risk factors (49, 25.3% vs 54, 14.2%; P = .001). Modified thrombolysis in cerebral infarction 3 revascularization was less common in the COVID-19 group (74, 39.2% vs 252, 67.2%; P < .001). Poor functional outcome at discharge (defined as modified Ranklin Scale 3-6) was more common in the COVID-19 group (150, 79.8% vs 132, 66.7%; P = .004). COVID-19 was independently associated with a lower likelihood of achieving modified thrombolysis in cerebral infarction 3 (odds ratio [OR]: 0.4, 95% CI: 0.2-0.7; P < .001) and unfavorable outcomes (OR: 2.5, 95% CI: 1.4-4.5; P = .002). CONCLUSION/CONCLUSIONS:COVID-19 was an independent predictor of incomplete revascularization and poor outcomes in patients with stroke due to LVO. Patients with COVID-19 with LVO were younger, had fewer cerebrovascular risk factors, and suffered from higher morbidity/mortality rates.

OBJECTIVE:Chronic subdural hematoma (CSDH) is a serious problem with an incidence of 20.6/100,000/year in North America and is posited to grow as the population ages. Middle Meningeal Artery (MMA) embolization is an upcoming therapy for treatment of CSDH. Among patients with CSDH who undergo MMA embolization outcomes are no different in patients who resume the antithrombotic (AT) after MMA embolization as compared to patients who don't resume AT. METHODS:We did retrospective review of all cases of MMA embolization in the setting of CSDH done over 2.5 years in 2 centers. Comparison of cases in which AT was resumed vs controls with no AT was performed. A successful outcome was defined as reduction of at least 50% volume in CSDH. Univariate analysis regarding all outcome measures for baseline variables was performed using Fisher exact test or t-test. Multivariate logistic regression with controlling for age, surgical evacuation of the hematoma. RESULTS:There were a total of 56 MMA embolization cases, 33 of them had no AT started and 23 of them had AT resumption at a mean of 2.4 days. About 40% of patients had surgical evacuation done prior to MMA embolization. There was no significant difference in hematoma reduction or volume even after adjusting for surgical evacuation (OR 1.00 95%CI 0.60- 1.67). Patients who had AT resumption had more CAD (71%vs 21% p= 0.001) and Afib (58% vs 18% p=0.002) necessitating AT. CONCLUSION/CONCLUSIONS:AT therapy can be safely resumed in CSDH after MMA embolization as there is no significant difference in CSDH volume reduction and recurrence.

StarVIBE is a 3D gradient-echo sequence with a radial, stack-of-stars acquisition having spatial resolution and tissue contrast. With newer sequences, it is important to be familiar with sequence tissue contrasts and appearance of anatomical variants. We evaluated 450 patients utilizing this sequence; 35 patients demonstrated fluffy "cotton wool" enhancement at the internal auditory canal fundus without clear pathology. We favor this represents anatomic neurovascular enhancement that StarVIBE is sensitive to and is a touch-me-not finding.

BACKGROUND:High-resolution vessel wall MRI (VWI) is increasingly used to characterize intramural disorders of the intracranial vasculature unseen by conventional arteriography. OBJECTIVE:To evaluate the use of VWI for surveillance of flow diverter (FD) treated aneurysms. MATERIALS AND METHODS/METHODS:Retrospective study of 28 aneurysms (in 21 patients) treated with a FD (mean 57 years; 14 female). All examinations included VWI and a contemporaneously obtained digital subtraction angiogram. Multiplanar pre- and post-gadolinium 3D, variable flip-angle T1 black-blood VWI was obtained using delay alternating nutation for tailored excitation (DANTE) at 3T. 3D time-of-flight MR angiography (MRA) was also carried out. Images were assessed for in-stent stenosis, aneurysm occlusion, presence and pattern/distribution of aneurysmal or parent vessel gadolinium enhancement. RESULTS:The VWI-MRI was performed on average at 361±259 days after the intervention. Follow-up DSA was performed at 338±254 days postintervention. Good or excellent black-blood angiographic quality was recorded in 22/28 (79%) pre-contrast and 21/28 (75%) post-contrast VWI, with no cases excluded for image quality. Aneurysm enhancement was noted in 24/28 (85.7%) aneurysms, including in 79% of angiographically occluded aneurysms and 100% of angiographically non-occluded aneurysms. Enhancement of the stented parent-vessel wall occurred significantly more often when aneurysm enhancement was present (92% vs 33%, p=0.049). CONCLUSION/CONCLUSIONS:Advanced VWI produces excellent depiction of FD-treated aneurysms, with robust evaluation of the parent vessel and aneurysm wall to an extent not achievable with conventional MRI/MRA. Gadolinium enhancement may, however, continue even after enduring catheter angiographic occlusion, confounding interpretation, and requiring cognizance of this potentially prolonged effect in such patients.

The aim of this study is to compare occlusion rate, complication rate, and clinical outcome of microsurgical clipping (MC) and advanced endovascular techniques (EVT) in unruptured anterior communicating artery-complex aneurysms (ACoCAs). We reviewed the scientific literature reporting occlusion rate, time of occlusion assessment, and clinical outcome of MC and EVT in patients with unruptured ACoCAs, from January 2009 to December 2019. We included in our analysis 25 studies and 872 patients with unruptured ACoCAs (434 treated with endovascular techniques and 438 with MC). Ninety-three (10.7%), 320 (36.7%), 21 (2.4%), and 438 (50.2%) were treated with flow diverter (FD), stent-assisted coiling (SAC), endosaccular devices (ES), and microsurgical clipping (MC) respectively. FD, SAC, ES, and MC subgroups presented minor complications in 11.8%, 3.8%, 14.3%, and 7.1% of cases (p=.016), and major complications in 3.2%, 4.4%, 0%, and 7.1% (p=.136) of patients. A total occlusion rate post-treatment has been achieved in 4.3%, 87.1%, 47.6%, and 98.2% of cases (p=.000), while at 12 months' follow-up in 50%, 66%, 83.3%, and 80% of patients (p=.001). FD, SAC, ES, and MC subgroups had a good clinical outcome at 12 months in 93.5%, 90.5%, 100%, and 67.8% of cases. MC is associated with higher post-treatment total occlusion rate, but higher complication and lower good clinical outcome rates. EVT are promising in treating unruptured anterior cerebral artery aneurysms with high margin of safety and good clinical outcome, despite the lower total occlusion rate.