The association between collateral status, recanalization and long term outcome in stroke patients treated with stent retrievers - Are there indications not to perform thrombectomy based on CT angiography?

BACKGROUND AND PURPOSE: To investigate the association between baseline pial collateral status on computed tomography angiography (CTA) with recanalization and functional outcome in patients with acute anterior circulation stroke treated with stent retriever thrombectomy. MATERIAL AND METHODS: Retrospective analysis of 87 patients from a prospective thrombectomy registry. Collateral status on CTA source images was categorized into good, moderate, and poor with the Tan and Miteff scores by two-blinded readers. Association between CTA collateral status and successful recanalization was investigated with univariate regression analysis. Multivariate logistic regression was used to analyse the association between collateral score and favourable clinical outcome (mRS 0-2) and death at follow-up. RESULTS: Mean age was 72.5 years and baseline median NIHSS score was 15. Patients with poor collaterals on Tan score had a significant higher mortality compared with moderate or good collaterals during a mean follow-up period of 5.2 months (85.7% vs. 30.6% vs. 25.7%, P<0.001). Univariate logistic regression analysis did not show a significant association between Tan score (OR 1.681, 95% CI 0.683-4.140) and successful recanalization. Higher age (OR 1.067, 95% CI 1.013-1.124; P=0.015) and lower Tan score (OR 0.421, 95% CI 0.192-0.922; P=0.031) were independent predictors of death at follow-up on multivariate analysis. The Miteff collateral score could be assessed only in 65 of the 87 patients and the Tan collateral score had a higher interrater reliability. CONCLUSIONS: Poor collaterals on CTA were associated with a very high rate of fatal outcome in anterior circulation stroke patients despite a high rate of successful recanalization with stent retrievers.

The pressure cooker technique for the treatment of brain AVMs.

Arteriovenous malformations (AVMs) may be cured by injecting liquid embolic agents such as Onyx. Reflux, however, can sometimes be difficult to control and may jeopardize a complete embolization. The pressure cooker technique (PCT) was designed to create an anti-reflux plug by trapping the detachable part of an Onyx-compatible microcatheter with coils and glue in order to obtain wedge-flow conditions, thereby enabling a better understanding of macrofistulous AVMs and a more comprehensive, forceful and controlled Onyx embolization. The PCT might enlarge the range of AVMs amenable to endovascular cure. Three illustrative cases are presented.

The sheeping technique or how to avoid exchange maneuvers.

INTRODUCTION: The arteries of bifurcation aneurysms are sometimes so angulated or tortuous that an exchange maneuver is necessary to catheterize them with a balloon or stent delivery catheter. Because of the risk of distal wire perforation associated with exchange maneuvers, we sought to find an alternative technique. METHODS: Our experience shows that a microcatheter tends to preferentially follow a previously placed microcatheter, even if the initial catheterization might be challenging. Accessing an artery with two microcatheters simultaneously may thus be an alternative to an exchange maneuver. Because of this tendency for catheters to behave like sheep following one another, we named this method the sheeping technique (ST). The ST consists of (a) first placing a 1.7 French microcatheter into the division branch requiring balloon or stent protection to straighten the course of the arteries in order to facilitate and (b) positioning in the same artery of a larger and stiffer balloon or stent microcatheter. Once the second balloon or stent microcatheter is in place, the first microcatheter can be pulled back and used to coil the aneurysm. RESULTS: Between January 2009 and December 2012, The ST was successfully used in 208/246 procedures (85%). Conversion to an exchange maneuver was necessary in 38/246 (15%). There were no arterial perforations or ischemic events related to the handling of both microcatheters. CONCLUSION: The sheeping technique may improve safety by replacing the need for an exchange maneuver during difficult balloon- or stent-assisted coiling.

The transvenous retrograde pressure cooker technique for the curative embolization of high-grade brain arteriovenous malformations.

BACKGROUND: Transvenous embolization of brain arteriovenous malformations (AVMs) can be curative. We aimed to evaluate the cure rate and safety of the transvenous retrograde pressure cooker technique (RPCT) using coils and n-butyl-2-cyanoacrylate as a venous plug. METHODS: All AVM patients treated via transvenous embolization between December 2004 and February 2017 in a single center were extracted from our database. Inclusion criteria were: inability to achieve transarterial cure alone; AVM < 3 cm; and single main draining vein. Outcome measures were immediate and 90 days' angiographic AVM occlusion rate, and morbidity and mortality at 30 days and 12 months, according to the modified Rankin Scale (mRS) score. RESULTS: Fifty-one patients (20 women; median age 47 years) were included. A majority (71%) were high grade (3 to 5 in the Spetzler-Martin classification). AVMs were deeply seated in 30 (59%) and cortical in 21 patients (41%). Thirty-three patients were previously embolized transarterially (65%). All patients but one were cured within a single session with the RPCT (96%). Cure was confirmed on follow-up digital subtraction angiography at 3 months in 82% of patients. Three patients experienced intracranial hemorrhage (6%), one requiring surgical evacuation. There were no deaths. One treatment-related major permanent deficit was observed (2.0%). Mean mRS before treatment, at 30 days, and 12 months after RPCT was 1.5, 1.5, and 1.3, respectively. CONCLUSIONS: The retrograde pressure cooker technique can be curative in carefully selected high-grade AVMs. Long-term follow-up and prospective studies are needed to confirm our results.

Angioplasty and Stenting of Intracranial Arterial Stenosis in Perforator-Bearing Segments: A Comparison Between the Anterior and the Posterior Circulation.

Background and Purpose: Subgroup analysis of the SAMMPRIS trial showed a higher rate of periprocedural perforator strokes with the Wingspan stent in the basilar artery in patients with symptomatic intracranial atherosclerotic stenosis (ICAS). It remains unclear whether angioplasty (PTA) alone or in combination with other stent types (PTAS) will yield similar results in perforator-bearing segments of the anterior and posterior circulation. Methods: We retrospectively analyzed the periprocedural complication rate, long term outcome and stroke etiology in 59 consecutive patients with ICAS of the middle cerebral artery (79 treatments) and 67 patients with ICAS of the intracranial vertebral and basilar artery (76 treatments) treated with PTA or PTAS from 2007 to 2015 in a high-volume neuro-interventional center. Results: Periprocedural symptomatic ischemic strokes occurred significantly more often in patients with posterior vs. anterior ICAS treatment (14.5 vs. 5.1%, p = 0.048). During a mean follow-up period of 19 (±23.7) months, 5 recurrent ischemic and 2 hemorrhagic strokes (10.4%) occurred in the territory of the treated artery in posterior circulation compared to 2 ischemic strokes in the anterior circulation (3.4%, p = 0.549). Overall, significantly more patients treated for a posterior ICAS suffered a periprocedural or follow-up stroke [25% vs. 11.4%, p = 0.024]. Periprocedural ischemic strokes were predominantly perforator strokes (73.3%), while all ischemic strokes during follow-up were caused by distal embolization (57.1%) or delayed stent occlusion (42.9%). There was no difference between PTA alone and PTAS. Conclusion: The periprocedural and long-term symptomatic stroke rate was significantly higher in the treatment of perforator-bearing arteries in the posterior circulation. There was no difference between PTA alone or PTAS.

Comparison of outcome and interventional complication rate in patients with acute stroke treated with mechanical thrombectomy with and without bridging thrombolysis.

BACKGROUND: No randomized trial has investigated the effect of mechanical thrombectomy (MT) alone in patients with acute stroke. There are conflicting results as to whether prior intravenous thrombolysis (IVT) facilitates subsequent MT, and data in patients treated with MT alone owing to contraindications to IVT are limited. OBJECTIVE: To compare consecutive patients treated with MT alone or with preceding IVT in a large tertiary neurointerventional center, with special emphasis on contraindications to IVT. METHODS: Retrospective analysis of 283 consecutive patients with acute ischemic stroke treated with MT in a tertiary neurovascular center over 14 months. Data on characteristics of periprocedural times, recanalization rate, complications, and long-term functional outcome were collected prospectively. RESULTS: Information on prior IVT and functional outcome was available in 250 patients. Mean (SD) follow-up period was 5.7 (5.1) months and 105 (42%) patients received both IVT and MT. No significant differences were found in successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) 2b/3, 73.8% vs 73.1, p=0.952), complication rates, and long-term favorable outcome (modified Rankin Scale 0-2, 35.2% vs 40%, p=0.444) between patients receiving MT plus IVT and those receiving MT alone. A favorable outcome in patients directly treated with MT alone who were eligible for IVT was achieved in 48.2%. Thrombectomy was safe and resulted in a favorable outcome in 32% of patients with absolute contraindications to IVT. CONCLUSIONS: Preceding use of IVT was not an independent predictor of favorable outcome in patients with acute stroke treated with MT and complication rates did not differ whether or not IVT was used. MT is safe and achieved a favorable outcome in one-third of patients with stroke ineligible for IVT.

Retrograde access to the posterior inferior cerebellar artery in balloon-assisted coiling of posterior inferior cerebellar artery aneurysms.

INTRODUCTION: Balloon-assisted coil embolization of proximal posterior inferior cerebellar artery (PICA) aneurysms may be limited by the inferiorly oriented, acutely angulated origin of the PICA from the vertebral artery. The aim of this study is to evaluate retrograde access to the PICA via the contralateral vertebral artery or the posterior communicating artery. METHODS: Twenty-nine proximal PICA aneurysms treated by balloon remodeling with navigation of the balloon in the PICA via the contralateral vertebral artery or posterior communicating artery were found in our database between January 2007 and December 2013 and were reviewed. RESULTS: Access to the PICA was made via the contralateral vertebral artery in 26 patients (90%), six of them (23%) with a hypoplastic V4 segment. In three patients (10%) the retrograde approach was made via the posterior communicating artery. After balloon remodeling, additional stenting was performed in 16 patients (55%). The complication rate was 3% (1 acute stent thrombosis). Grade 0 or 1 occlusion was obtained in all patients at completion angiography. No recurrence was found during follow-up. CONCLUSIONS: Retrograde access to the PICA to perform balloon-assisted coil embolization of proximal PICA aneurysms with or without additional stenting after coiling is safe and effective. Hypoplastic V4 segment of the contralateral vertebral artery is not a contraindication.