Christopher T. Primiani

Vessel perforation during stent retriever thrombectomy for acute ischemic stroke: technical details and clinical outcomes

Background Vessel perforation during stent retriever thrombectomy is a rare complication; typically only single instances have been reported. Objective To report on a series of patients whose stent retriever thrombectomy was complicated by intraprocedural vessel perforation and discuss its potential mechanisms, rescue treatment strategies, and clinical significance. Methods Cases with intraprocedural vessel perforation, where a stent retriever was used either as a primary treatment approach or as a part of a direct aspiration first pass technique (ADAPT), were included in the final analysis. Clinical data, procedural details, radiographic and clinical outcomes were collected from nine participating centers. Results Intraprocedural vessel perforation during stent retriever thrombectomy occurred in 16 (1.0%) of 1599 cases. 63% of intraprocedural perforations occurred at distal locations. Endovascular rescue techniques (most commonly, intracranial balloon occlusion for tamponade) were attempted in 50% of cases. Procedure was aborted without any rescue attempts in 44% of cases. Mortality during hospitalization and at 3 months was 56% and 63%, respectively. 25% of patients achieved good functional outcome at 3 months after the procedure. Conclusions Intraprocedural perforations during stent retriever thrombectomy were rare, but when they occurred were associated with high mortality. Perforations most commonly occurred at distal occlusion sites and were often characterized by difficulty traversing the occlusion with a microcatheter or microwire, or while withdrawing the stent retriever. Nevertheless, 25% of patients had a favorable functional outcome, suggesting that in some patients with this complication good neurological recovery is achievable.

Endovascular treatment of middle cerebral artery M2 occlusion strokes: Clinical and procedural predictors of outcomes

BACKGROUND: Patients with strokes from M2 segment middle cerebral artery (MCA) occlusion have been underrepresented in recent randomized trials of endovascular therapy. OBJECTIVE: To better understand the clinical, imaging, and procedural predictors of successful recanalization and clinical outcomes in this population of patients. METHODS: We performed a multicenter retrospective analysis of consecutive patients with acute MCA M2 segment occlusion who underwent thrombectomy with stent retrievers or primary aspiration thrombectomy (including A Direct Aspiration First Pass Technique approach). We correlated clinical and radiographic outcomes with demographic, clinical, and technical characteristics. RESULTS: One hundred and seventeen patients were included in analysis (median admission National Institutes of Health stroke scale [NIHSS] score 15, mean age 67.0 ± 14.5, 42% females). Good clinical outcome at 3 months (modified Rankin scale [mRS] ≤ 2) was achieved in 56% of patients. Treatment beyond 6 h of symptoms onset (P = .69, OR 0.80, 95% CI 0.38‐1.73) and age over 80 (P = .47, OR 0.65, 95% CI 0.25‐1.70) were not predictive of poor outcome. NIHSS > 15 was a strong predictor of clinical outcome, based on mRS distribution at 3 months (P = .0085, OR 0.35, 95% CI 0.16‐0.74). Direct aspiration and primary stent retriever thrombectomy approaches showed similar radiographic and clinical success rates. CONCLUSION: Advanced age and time to treatment beyond 6 h from symptom onset were not predictive of clinical outcome with thrombectomy. NIHSS score above 15 was a strong predictor of outcome. Direct aspiration and primary stent retriever thrombectomy showed similar efficacy.

Treatment of blood blister aneurysms of the internal carotid artery with flow diversion

Background Blood blister aneurysms (BBA) are a rare subset of intracranial aneurysms that represent a therapeutic challenge from both a surgical and endovascular perspective. Objective To report multicenter experience with flow diversion exclusively for BBA, located at non-branching segments along the anteromedial wall of the supraclinoidal internal carotid artery (ICA). Methods Consecutive cases of BBA located at non-branching segments along the anteromedial wall of the supraclinoidal ICA treated with flow diversion were included in the final analysis. Results 49 patients with 51 BBA of the ICA treated with devices to achieve the flow diversion effect were identified. 43 patients with 45 BBA of the ICA were treated with the pipeline embolization device and were included in the final analysis. Angiographic follow-up data were available for 30 patients (32 aneurysms in total); 87.5% of aneurysms (28/32) showed complete obliteration, 9.4% (3/32) showed reduced filling, and 3.1% (1/32) persistent filling. There was no difference between the size of aneurysm (≤2 mm vs >2 mm) or the use of adjunct coiling and complete occlusion of the aneurysm on follow-up (P=0.354 and P=0.865, respectively). Clinical follow-up data were available for 38 of 43 patients. 68% of patients (26/38) had a good clinical outcome (modified Rankin scale score of 0–2) at 3 months. There were 7 (16%) immediate procedural and 2 (5%) delayed complications, with 1 case of fatal delayed re-rupture after the initial treatment. Conclusions Our data support the use of a flow diversion technique as a safe and effective therapeutic modality for BBA of the supraclinoid ICA.

ASPECTS (Alberta Stroke Program Early CT Score) Measurement Using Hounsfield Unit Values When Selecting Patients for Stroke Thrombectomy

Background and Purpose— The ASPECTS (Alberta Stroke Program Early CT Score) is a quantitate score that measures the extent of early ischemic changes. Our aim was to investigate how measurement of ASPECTS using Hounsfield unit (HU) values on initial noncontrast head computerized tomography (CT) correlates with the extent of final infarct on follow-up imaging. Methods— Cases of acute stroke from the middle cerebral artery M1 occlusion in which complete recanalization (TICI [Thrombolysis in Cerebral Infarction] 3) was achieved were included for analysis. Using HU ratio (HU affected/HU control hemisphere) and HU difference (HU control−HU affected hemisphere) values, ASPECTS was measured on initial CT imaging and correlated with final ASPECTS at 24 hours. The study cohort consisted of 41 patients with acute stroke from the M1 occlusion. The mean time from stroke symptoms onset to baseline head CT imaging was 264 minutes and from CT to TICI 3 recanalization was 142 minutes. Results— HU ratio within the 0.94 to 0.96 ranges showed the highest correlation coefficient and lowest mean and median errors with the final ASPECTS. The difference of 2.0 HU between the 2 hemispheres demonstrated the higher correlation coefficient (r=0.71; P<0.0001) and the lowest mean and median absolute errors (1.4 and 1, respectively). Conclusions— We established a simple algorithm for rapid and accurate assessment of ASPECTS on baseline CT imaging to predict the extent of final stroke in patients with emergent large vessel occlusion who undergo endovascular revascularization.

Neuroimaging of Cavernous Malformations

Purpose of ReviewCerebral cavernous malformations (CCMs) are common vascular abnormalities often discovered on imaging as an incidental finding. The most common clinical presentations of CCMs include seizure, headache, focal neurological deficits, and intracranial hemorrhage. This article discusses the most recent guidelines including imaging diagnostic criteria and radiographic standards of CCMs and reviews the utility of currently available imaging techniques.Recent FindingsGradient echo T2*-weighted imaging and susceptibility-weighted imaging are the recommended imaging protocols for evaluation of suspected CCMs. Diffusion tensor imaging-based tractography provides visualization of the eloquent white matter tracks in the brain. This imaging is increasingly used in clinical practice to assist in selecting the optimal surgical approach, especially for brainstem lesions. Quantitative susceptibility mapping and dynamic contrast-enhanced quantitative perfusion are presently considered experimental. Its proposed value might prove helpful in the future to monitor disease activity and response to treatments.SummaryThe choice of imaging modality of CCMs depends on the goals the clinician expects to achieve, such as establishing the initial diagnosis, follow-up and monitoring disease activity, preoperative, intraoperative, and postoperative evaluation, or research and experimental work on patients with CCM.