Cortese, Jonathan

ABSTRACT Endoluminal flow diverters are increasingly used to treat cerebral aneurysms. Despite good aneurysm occlusion efficacy, delayed ischemic complications due to side branch or perforator occlusion remain a serious concern. However, the mechanisms leading to side branch occlusion are poorly understood. To investigate these mechanisms, a combination of animal and computational models was utilized. Flow diverters were deployed in four rabbit superior mesenteric artery (SMA) and studied with computational fluid dynamics (CFD) and a previously developed fibrin dynamics model. Subject‐specific vascular models were reconstructed from 3D rotational angiography images and flow conditions were derived from Doppler ultrasound velocity measurements. Flow diverting devices were virtually deployed within the vascular models under guidance from angiography images. Coupled flow and fibrin production, transport, and adhesion simulations were carried out and the effects of fibrin accumulation at the origin of jailed side branches after flow diverter implantation were analyzed. The results of the computational models suggest significant fibrin accumulation across the struts of all flow diverting devices jailing side branches. Larger accumulation was observed at the more distal branches. However, minor flow alterations were produced which were not detectable in angiography sequences. These results were in agreement with experimental observations. On the other hand, fibrin accumulation alone did not explain complete side branch occlusions, which are likely the result of the interaction between initial fibrin accumulation and subsequent cell migration from the peripheral parent artery.

Background Delayed aneurysm rupture (DAR) is a potentially devastating complication after flow-diverters (FD) deployment and their exact mechanisms are still unclear. The purpose of this meta-analysis is to synthesize the latest evidence on DAR after FD treatment and identify predictive factors. Methods A systematic review and meta-analysis were conducted according to established protocols. Searches were conducted in PubMed, Scopus, Web of Science, and Embase databases up to June 2024 using variations of “aneurysm “and “delayed aneurysm rupture” terms. Original studies reporting DAR and including more than five patients were included. All analyses were conducted in R software (version 4.4.2), employing the “meta” and “tableone” packages. Results 64 studies with 9820 patients were included, large aneurysm size (OR=1.08, 95% CI (1.02, 1.14), P value=0.008), intra-aneurysmal thrombus (OR=1.05, 95% CI (1.01, 1.09), P value=0.010) and posterior circulation location (OR=1.02, 95% CI (1.00, 1.04), P value=0.014) were significant risk factors for DAR. The pooled prevalence of DAR was 1.40%, with a rate of 1.18% after removing outliers. DAR occurred within 30 days in 66.7% of cases, with a mortality rate of 73.3% at discharge. Conclusion DAR following flow diversion treatment is an uncommon but devastating complication and remains a limitation of the technique. It is influenced by factors such as large aneurysm size, intra-aneurysmal thrombosis, and posterior circulation involvement. The first 30 days post-procedure represent a particularly high-risk period. Despite advancements in FD technology, significant gaps remain, highlighting the need for further research to improve risk assessment and treatment strategies.

Background The Woven EndoBridge (WEB) device is an effective treatment for wide‐neck aneurysms (WNA). This study aims to identify and compare anatomical and procedural factors that predicts the aneurysm occlusion, both adequate and inadequate after WEB device treatment. Methods A systematic review and meta‐analysis were conducted using PubMed, Embase, Scopus, and Web of Science, including studies up to October 25, 2024. Data on angiographic outcomes of WEB occlusion were extracted and analyzed using R version 4.4.2 Results Nine studies (790 patients) were included. Female patients were 1.64 times more likely to achieve adequate occlusion than males (OR: 1.64, 95% CI: [1.06, 2.52], p = 0.026). Regular‐shaped aneurysms had a 2.44‐fold higher likelihood of adequate occlusion compared to irregular ones (OR: 0.41, 95% CI: [0.23, 0.74]). Aneurysm neck size was significantly smaller in the adequate occlusion group (3.9 mm vs. 4.4 mm, MD: ‐0.48 mm, 95% CI: [‐0.78, ‐0.18], p = 0.002). Maximum aneurysm diameter was also smaller in the adequate occlusion group (5.7 mm vs. 6.8 mm, MD: ‐1.13 mm, 95% CI: [‐1.69, ‐0.57], p < 0.001). Aneurysm height was also significantly lower than the inadequate occlusion group (5.4 mm vs. 6.3 mm, MD: ‐0.92 mm, 95% CI: [‐1.55, ‐0.29], p = 0.004). Conclusion Smaller aneurysm dimensions, regular shape, and female gender were associated with higher adequate occlusion rates after WEB treatment. These findings may guide patient selection strategies for optimizing aneurysm occlusion. Further high‐quality studies are needed to confirm these associations. image image

BACKGROUND AND OBJECTIVES: Embolization is part of multidisciplinary brain arteriovenous malformations (AVMs) treatment, yet safety data for novel liquid embolization agents (LEAs) such as Squid and PHIL remain limited. This study reports complications and outcomes from curative embolization using Onyx, Squid, PHIL, and Glue. METHODS: Adult patients with brain AVMs treated with LEAs from July 2015 to December 2022 were reviewed for intraprocedural technical issues, postoperative hemorrhagic, and ischemic complications. Minor (modified Rankin Scale ≤2) and major complication rate (morbidity/modified Rankin Scale >2), mortality, and 6-month angiographic cure rate were evaluated. RESULTS: In total, 135 patients (62.2% male, mean age 41.7 ± 15.1 years) with 206 embolizations (34% Onyx, 18.9% Squid, 17.5% PHIL, 28.2% Glue) were included. Overall, 87.4% procedures were in ruptured AVMs and 84% treated by the transarterial technique (84%). The 6-month angiographic cure rate was 53.3%, higher when nonadhesive LEAs were used than Glue (65.3% vs 17.6%, P < .001). In adjusted analysis, only eloquent location (odds ratio [OR] = 4.4; P = .007) and Glue (OR = 9.1; 95% CI 2.9-28.9, P < .001) were predictors of lower angiographic occlusion rate, whereas size had an inverse correlation (OR = 0.67; P = .019). Technical procedural complications, hemorrhagic, and ischemic rates were 10.2% (2.2% morbidity), 13.1% (3.7% morbidity and 2.2% mortality), and 9.2% (2.2% morbidity, 0% mortality), respectively, regardless of the preferred LEA. Minor, major complications, and mortality rates were 3.7%, 4.4%, and 2.2%, respectively. Hemorrhage was the major contributor to morbidity and mortality, whereas deep venous drainage was an independent predictor of hemorrhage and mortality. CONCLUSION: PHIL and Squid demonstrated complication and angiographic cure rates comparable with Onyx. However, curative embolization of brain AVMs resulted in only moderate angiographic occlusion. Larger multicenter studies with standardized operator protocols, cost-effectiveness assessments, and extended follow-up are warranted to validate these findings.

Cerebrospinal fluid venous fistulas (CSFVF) can lead to spontaneous intracranial hypotension, causing debilitating symptoms in patients. The transvenous embolization technique has been developed to occlude leakage sites via an endovascular approach. However, the spinal venous anatomy remains relatively unfamiliar to many neurointerventionalists. This technical video presents a swine model designed to train physicians in navigating the spinal venous system, performing embolization injections, observing their spread, and testing new embolization systems for treating CSFVF. Although there are slight anatomical differences, the spinal venous system in swine closely resembles that of humans, including its navigability and employing liquid embolic agents. We successfully embolized multilevel spinal vasculature that can potentially drain into a fistula formation, without any complications.