Faculty Bibliography

BACKGROUND:Whether to approach distal occlusions endovascularly or not in medium-sized vessels secondary to proximal large vessel occlusion stroke remains unanswered. OBJECTIVE:To investigates the technical feasibility and safety of thrombectomy for secondary posterior circulation distal, medium vessel occlusions (DMVO). METHODS:TOPMOST (Treatment fOr Primary Medium vessel Occlusion STroke) is an international, retrospective, multicenter, observational registry of patients treated for distal cerebral artery occlusions. This study subanalysis endovascularly treated occlusions of the posterior cerebral artery in the P2 and P3 segment secondary preprocedural or periprocedural thrombus migration between January 2014 and June 2020. Technical feasibility was evaluated with the modified Thrombolysis in Cerebral Infarction (mTICI) scale. Procedural safety was assessed by the occurrence of symptomatic intracranial hemorrhage (sICH) and intervention-related serious adverse events. RESULTS:Among 71 patients with secondary posterior circulation DMVO who met the inclusion criteria, occlusions were present in 80.3% (57/71) located in the P2 segment and in 19.7% (14/71) in the P3 segment. Periprocedural migration occurred in 54.9% (39/71) and preprocedural migration in 45.1% (32/71) of cases. The first reperfusion attempt led in 38% (27/71) of all cases to mTICI 3. On multivariable logistic regression analysis, increased numbers of reperfusion attempts (adjusted odds ratio (aOR)=0.39, 95% CI 0.29 to 0.88, p=0.009) and preprocedural migration (aOR=4.70, 95% CI,1.35 to 16.35, p=0.015) were significantly associated with mTICI 3. sICH occurred in 2.8% (2/71). CONCLUSION/CONCLUSIONS:Thrombectomy for secondary posterior circulation DMVO seems to be safe and technically feasible. Even though thrombi that have migrated preprocedurally may be easier to retract, successful reperfusion can be achieved in the majority of patients with secondary DMVO of the P2 and P3 segment.

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.

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: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.

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.

BACKGROUND:The dural vasculature plays a key role in several important conditions, including dural fistulas and subdural collections. While in vivo investigations of intrinsic dural arterial angioarchitecture are rare, no angiographic studies of dural venous drainage exist to our knowledge. OBJECTIVE:To describe methods by which dural venous drainage might be visualized with current angiographic equipment and technique, and to correlate our results with existing ex vivo literature. METHODS:Digital subtraction angiography and 3D angiography (rotational and Dyna CT) of dural neurovasculature were acquired in the context of subdural hematoma embolization and normal dura. Protocols for visualization of dural venous drainage were established, and findings correlated with ex vivo studies. RESULTS:Meningeal arteries supply both the skull and dura. Normal dural enhancement is accentuated by the presence of hypervascular membranes. Intrinsic meningeal veins/sinuses parallel outer layer arteries with well-known tram-tracking appearance. Dura adjacent to main arterial trunks drains via skull base foramina into the pterygopalatine venous plexus, or via emissary veins into the temporalis venous plexus. Dura near the sinuses drains into venous pouches adjacent to the sinus, before emptying into the sinus proper-possibly the same pouches implicated in the angioarchitecture of dural fistulas. Finally, posterior temporoparietal convexity dura, situated in a watershed-like region between middle and posterior meningeal territories, frequently empties into diploic and emissary veins of the skull. Wide variation in balance is expected between these three routes. Drainage patterns appear to correlate with venous embryologic investigations of Padget and ex vivo studies in adults. CONCLUSIONS:Continued attention to dural venous drainage may prove useful in the diagnosis and management of dural-based vascular diseases.

BACKGROUND:Over the past several years there has been increased interest in the use of the Sofia aspiration system (MicroVention, Tustin, California) as a primary aspiration catheter. OBJECTIVE:To perform a multicenter retrospective study examining the efficacy of the Sofia aspiration catheter as a standalone aspiration treatment for large vessel occlusion. METHODS:Consecutive cases in which the Sofia catheter was used for aspiration thrombectomy for large vessel occlusion were included. Exclusion criteria were the following: (1) Sofia not used for first pass, and (2) a stent retriever used as an adjunct on the first pass. The primary outcome of the study was first pass recanalization (Thrombolysis in Cerebral Infarction (TICI) 2c/3). Secondary outcomes included first pass TICI 2b/3, crossover to other thrombectomy devices, number of passes, time from puncture to recanalization, and complications. RESULTS:323 patients were included. First pass TICI 2c/3 was achieved in 49.8% of cases (161/323). First pass TICI 2b/3 was achieved in 69.7% (225/323) of cases. 74.8% had TICI 2b/3 with the Sofia alone. Crossover to other thrombectomy devices occurred in 29.1% of cases (94/323). The median number of passes was 1 (IQR=1-3). Median time from puncture to recanalization was 26 min (IQR=17-45). Procedure related complications occurred in 3.1% (10/323) of cases. CONCLUSION/CONCLUSIONS:Our study highlights the potential advantage of the Sofia aspiration catheter for primary aspiration thrombectomy in acute ischemic stroke. High rates of first pass recanalization with low crossover rates to other thrombectomy devices were achieved. Median procedure time was low, as were procedural complications.

Cavernous sinus dural arteriovenous fistulas (CS-DAVF) can have an indolent course, with insidious onset, but still showing a high likelihood of spontaneous resolution.1 Nevertheless, symptoms in a subset of patients evolve more rapidly, with malignant signs on imaging, warranting intervention.2 We report on a patient in his 40s presenting with redness and proptosis of the right eye, intermittent blurred vision and diplopia. Once ophthalmological examination revealed increased intraocular pressure and imaging showed cortical venous congestion, the decision was made to obliterate a CS-DAVF involving the posteromedial right cavernous sinus.Multiple arteries including branches of the ascending pharyngeal artery, occipital artery and bilateral meningohypophyseal trunks supplied the fistula. Once transarterial embolization was deemed unsafe and both inferior petrosal sinuses did not grant access to the right cavernous sinus, a direct puncture to the cavernous sinus was performed to successfully coil the involved compartments.3-5 The aid of DynaCT imaging and needle guidance software is emphasized (video 1).neurintsurg;neurintsurg-2020-017118v1/V1F1V1Video 1.

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/CONCLUSIONS: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.

Background There are multiple tools available to visualize the retinal and choroidal vasculature of the posterior globe. However, there are currently no reliable in vivo imaging techniques that can visualize the entire retrobulbar course of the retinal and ciliary vessels. Purpose To identify and characterize the central retinal artery (CRA) using cone-beam CT (CBCT) images obtained as part of diagnostic cerebral angiography. Materials and Methods In this retrospective study, patients with catheter DSA performed between October 2019 and October 2020 were included if CBCT angiography included the orbit in the field of view. The CBCT angiography data sets were postprocessed with a small field-of-view volume centered in the posterior globe to a maximum resolution of 0.2 mm. The following were evaluated: CRA origin, CRA course, CRA point of penetration into the optic nerve sheath, bifurcation of the CRA at the papilla, visualization of anatomic variants, and visualization of the central retinal vein. Descriptive statistical analysis was performed. Results Twenty-one patients with 24 visualized orbits were included in the analysis (mean age, 55 years ± 15; 14 women). Indications for angiography were as follows: diagnostic angiography (n = 8), aneurysm treatment (n = 6), or other (n = 7). The CRA was identified in all orbits; the origin, course, point of penetration of the CRA into the optic nerve sheath, and termination in the papilla were visualized in all orbits. The average length of the intraneural segment was 10.6 mm (range, 7-18 mm). The central retinal vein was identified in six of 24 orbits. Conclusion Cone-beam CT, performed during diagnostic angiography, consistently demonstrated the in vivo central retinal artery, demonstrating excellent potential for multiple diagnostic and therapeutic applications. © RSNA, 2021 Online supplemental material is available for this article.