BackgroundA direct aspiration first pass thrombectomy (ADAPT) is a fast-growing technique for which a broad catalog of catheters that provide a wide range of aspiration forces can be used. We aimed to characterize different catheters' aspiration performance on stiff clots in an in vitro vascular model. We hypothesized that labeled catheter inner diameter (labeled-ID) is not the only parameter that affects the aspiration force (asp-F) and that thrombus–catheter tip interaction and distensibility also play a major role.MethodsWe designed an experimental setup consisting of a 3D-printed carotid artery immersed in a water deposit. We measured asp-F and distensibility of catheter tips when performing ADAPT on a stiff clot analog larger than catheter labeled-ID. Correlations between asp-F, catheter ID, and tip distensibility were statistically assessed.ResultsExperimental asp-F and catheter labeled-ID were correlated (r=0.9601; P<0.01). The relative difference between experimental and theoretical asp-F (obtained by the product of the tip’s section area by the vacuum pressure) correlated with tip’s distensibility (r=0.9050; P<0.01), evidencing that ADAPT performance is highly influenced by catheter tip shape-adaptability to the clot and that the effective ID (eff-ID) may differ from the labeled-ID specified by manufacturers. Eff-ID showed the highest correlation with experimental asp-F (r=0.9944; P<0.01), confirming that eff-ID rather than labeled-ID should be considered to better estimate the device efficiency.ConclusionsCatheter tip distensibility can induce a significant impact on ADAPT performance when retrieving a stiff clot larger than the device ID. Our findings might contribute to optimizing thrombectomy strategies and the design of novel aspiration catheters.

Background: Acute ischemic stroke with large or medium-vessel occlusion associated with intracranial artery calcification (IAC) is an infrequent phenomenon presumably associated with intracranial atherosclerotic disease. We aimed to characterize IAC and its impact on endovascular treatment outcomes. Methods: We performed a retrospective cross-sectional study of consecutive patients with stroke treated with thrombectomy from January 2020 to July 2021 in our institution. We described IAC findings (length, density, and location pattern) on baseline noncontrast computed tomography. Patients were divided into 3 groups: IAC related to the occlusion location (symptomatic-IAC group), unrelated to the occlusion (asymptomatic-IAC group), and absence of any IAC (non-IAC group). We analyzed the association between the IAC profile and outcomes using logistic regression models. Intracranial angioplasty and stenting were considered rescue treatments. Results: Of the 393 patients included, 26 (6.6%) patients presented a symptomatic-IAC, 77 (19.6%) patients an asymptomatic-IAC, and in 290 (73.8%) patients no IAC was observed. The rate of failed recanalization (expanded Thrombolysis in Cerebral Infarction 0-2a) before rescue treatment was higher in symptomatic-IAC (65.4%) than in asymptomatic-IAC (15.6%; P <0.001) or non-IAC (13.4%; P <0.001). Rescue procedures were more frequently performed in symptomatic-IAC (26.9%) than in asymptomatic-IAC (1.3%; P <0.001) and non-IAC (4.1%; P <0.001). After adjusting for identifiable clinical and radiological confounders, symptomatic-IAC emerged as an independent predictor of failed recanalization (odds ratio, 11.89 [95% CI, 3.94–35.91]; P <0.001), adoption of rescue procedures (odds ratio, 12.38 [95% CI, 2.22–69.09]; P =0.004), and poor functional outcome (90-day modified Rankin Scale score ≥3; odds ratio, 3.51 [95% CI, 1.02–12.00]; P =0.046). Conclusions: The presence of IAC related to the occlusion location is associated with worse angiographic and functional outcomes. Therefore, identification of symptomatic-IAC on baseline imaging may guide optimal endovascular treatment strategy, predicting the need for intracranial stenting and angioplasty.

Background Remote access of trainees to training centers via video streaming (tele-observership, e‑fellowship) emerges as an alternative to acquire knowledge in endovascular interventions. Situational awareness is a summary term that is also used in surgical procedures for perceiving and understanding the situation and projecting what will happen next. A high situational awareness would serve as prerequisite for meaningful learning success during tele-observerships. We hypothesized that live perception of the angiographical procedures using streaming technology is feasible and sufficient to gain useful situational awareness of the procedure. Methods During a European tele-observership organized by the European Society of Minimally Invasive Neurological Therapy (ESMINT) and its trainee association (EYMINT), a total of six neurointerventional fellows in five countries observed live cases performed by experienced neurointerventionalists (mentors) in six different high-volume neurovascular centers across Europe equipped with live-streaming technology (Tegus Medical, Hamburg, Germany). Cases were prospectively evaluated during a 12-month period, followed by a final questionnaire after completion of the course. Results A total of 102/161 (63%) cases with a 1:1 allocation of fellow and mentor were evaluated during a 12-month period. Most frequent conditions were ischemic stroke (27.5%), followed by embolization of unruptured aneurysms (25.5%) and arteriovenous malformations (AVMs) (15.7%). A high level of situational awareness was reported by fellows in 75.5% of all cases. After finishing the program, the general improvement of neurointerventional knowledge was evaluated to be extensive (1/6 fellows), substantial (3/6), and moderate (2/6). The specific fields of improvement were procedural knowledge (6/6 fellows), technical knowledge (3/6) and complication management (2/6). Conclusion Online streaming technology facilitates location-independent training of complex neurointerventional procedures through high levels of situational awareness and can therefore supplement live hands-on-training. In addition, it leads to a training effect for fellows with a perceived improvement of their neurointerventional knowledge.

Background Treatment of brain arteriovenous malformations (b-AVM) carries a risk of iatrogenic injury to eloquent brain regions. Intraoperative neuro-monitoring (IONM) has increasingly been used to monitor spontaneous or evoked neural activity during neurosurgery, but its use is not as well characterized in the endovascular treatment (EVT) of b-AVMs. We aimed to provide a systematic review and meta-analysis of studies reporting any neurological deficit after b-AVM embolization with IONM, with or without provocative test (PT), and no-IONM. Methods This systematic review followed the PRISMA guidelines. Medline, EMBASE, and Scopus were searched from conception until March 1, 2022 for studies evaluating EVT with IONM and PT. Primary outcome was the rate of postoperative neurological deficits in EVT with IONM versus no-IONM, while secondary outcome was the subanalysis of IONM with or without PT. Meta-analysis was performed using the Mantel–Haenszel method and random effects modeling. Results Six studies reached synthesis. Out of a total of 192 EVT, 14 events occurred. Results demonstrated a nonsignificant trend favoring IONM compared to no-IONM to prevent neurological deficits (OR 0.09, 95% CI 0–4.68). Among the EVT with IONM, PT was done in 411 branches with 10 events (0.2%) despite a negative PT. There was a nonsignificant trend favoring IONM plus PT compared to IONM without PT (OR 0.16, 95% CI 0.02–1.07). Conclusions Our study suggests that b-AVM EVT with IONM plus PT might reduce rates of postprocedural neurological deficits compared with EVT without IONM. Further studies are needed to confirm these results.

Transradial access (TRA) has become the standard approach for cardiac intervention, with a large body of evidence demonstrating a lower incidence of vascular complications, better patient experience and cost reduction. There has been increasing interest in using TRA both for diagnostic neuroangiography and for interventional neurovascular procedures. This aim of this article is to discuss the advantages and limitations of TRA for neurointerventions. General technical details, such as pre-procedure recommendations, prevention of spasm and occlusion, haemostasis protocols and distal TRA puncture, are also described, along with the specific technical details of TRA for aneurysm embolisation, stroke thrombectomy and other neurovascular interventions. TRA provides additional tools to the neurointerventionist and – with appropriate training – the whole spectrum of intervention procedures can be achieved using this approach.