Citations

Background: Despite the well-established potent benefit of mechanical thrombectomy (MT) for large vessel occlusion (LVO) stroke, access to MT has not been studied globally. We conducted a worldwide survey of countries on 6 continents to define MT access (MTA), the disparities in MTA, and its determinants on a global scale. Methods: Our survey was conducted in 75 countries through the Mission Thrombectomy 2020+ global network between November 22, 2020, and February 28, 2021. The primary end points were the current annual MTA, MT operator availability, and MT center availability. MTA was defined as the estimated proportion of patients with LVO receiving MT in a given region annually. The availability metrics were defined as ([current MT operators×50/current annual number of estimated thrombectomy-eligible LVOs]×100 = MT operator availability) and ([current MT centers×150/current annual number of estimated thrombectomy-eligible LVOs]×100= MT center availability). The metrics used optimal MT volume per operator as 50 and an optimal MT volume per center as 150. Multivariable-adjusted generalized linear models were used to evaluate factors associated with MTA. Results: We received 887 responses from 67 countries. The median global MTA was 2.79% (interquartile range, 0.70–11.74). MTA was <1.0% for 18 (27%) countries and 0 for 7 (10%) countries. There was a 460-fold disparity between the highest and lowest nonzero MTA regions and low-income countries had 88% lower MTA compared with high-income countries. The global MT operator availability was 16.5% of optimal and the MT center availability was 20.8% of optimal. On multivariable regression, country income level (low or lower–middle versus high: odds ratio, 0.08 [95% CI, 0.04–0.12]), MT operator availability (odds ratio, 3.35 [95% CI, 2.07–5.42]), MT center availability (odds ratio, 2.86 [95% CI, 1.84–4.48]), and presence of prehospital acute stroke bypass protocol (odds ratio, 4.00 [95% CI, 1.70–9.42]) were significantly associated with increased odds of MTA. Conclusions: Access to MT on a global level is extremely low, with enormous disparities between countries by income level. The significant determinants of MT access are the country’s per capita gross national income, prehospital LVO triage policy, and MT operator and center availability.

Background Traditional endovascular treatments of giant intracranial aneurysms are associated with high rates of complications and retreatment. Our objective was to examine the safety and long-term efficacy of the Pipeline Embolization Device for treatment of these aneurysms. Methods This retrospective study using the IntrePED database included all patients with giant intracranial aneurysms treated with the Pipeline device between July 2008 and February 2013. Efficacy outcomes were stratified by using the Raymond-Roy Occlusion Classification. Predefined safety outcomes included spontaneous rupture of the target aneurysm; ipsilateral intracranial hemorrhage; ischemic stroke; parent artery stenosis; and sustained cranial neuropathy. Results Sixty-six embolizations were performed to treat 63 giant intracranial aneurysms (including 2 ruptured): 49 (77.8%) in the anterior and 14 (22.2%) in the posterior circulation. The median follow-up was 22.4 (0.1–60.5) months. Class I angiographic occlusion was achieved in 72.0% (36/50). The neurological morbidity/mortality rate was 23.8% (15/63), with higher rates in the posterior circulation than in the anterior circulation (22.4% vs. 28.6%). Among seven deaths, five had neurological causes. The procedure-related neurological morbidity and mortality rates were 22.7% (15/66) and 7.6% (5/66), respectively. The spontaneous rupture rate was 4.5% (3/66). Two spontaneous ruptures (1 death), 4/4 postprocedural intracranial hemorrhages, and 6/9 ischemic events occurred within 30 days. In-stent stenosis and new-onset cranial neuropathy were not observed during the angiographic follow-up period. Conclusions Although procedure-related neurological morbidity/mortality rates were not insignificant, this study confirms the feasibility and long-term efficacy of the Pipeline Embolization Device to treat giant intracranial aneurysms.

Background The Woven EndoBridge (WEB) device is a novel intrasaccular flow disruptor tailored for bifurcation aneurysms. We aim to describe the degree of aneurysm occlusion at the latest follow-up, and the rate of complications of aneurysms treated with the WEB device stratified according to rupture status. Methods Our data were taken from the WorldWideWeb Consortium, an international multicenter cohort including patients treated with the WEB device. Aneurysms were classified into two groups: ruptured and unruptured. We compared clinical and radiologic outcomes of both groups. Propensity score matching (PSM) was done to match according to age, gender, bifurcation, location, prior treatment, neck, height, dome width, daughter sac, incorporated branch, pretreatment antiplatelets, and last imaging follow-up. Results The study included 676 patients with 691 intracranial aneurysms (529 unruptured and 162 ruptured) treated with the WEB device. The PSM analysis had 55 pairs. In both the unmatched (85.8% vs 84.3%, p=0.692) and matched (94.4% vs 83.3%, p=0.066) cohorts there was no significant difference in the adequate occlusion rate at the last follow-up. Likewise, there were no significant differences in both ischemic and hemorrhagic complications between the two groups. There was no documented aneurysm rebleeding after WEB device implantation. Conclusion There was no significant difference in both the radiologic outcomes and complications between unruptured and ruptured aneurysms. Our findings support the feasibility of treatment of ruptured aneurysms with the WEB device.

Introduction: Predicting the course of aneurysms after treatment with flow diverters is important to prognosticate long term outcomes and optimize interventions. Hypothesis: Aneurysm occlusion after flow diversion can be predicted using post-treatment flow information. Methods: Flows in experimental aneurysms in rabbits (n=15) and clinical cases (n=23) were evaluated with computational fluid dynamics. Subject-specific models were created from 3D angiographies. Flow conditions were measured with ultrasound in the rabbits, and derived from measurements in normal subjects in the clinical cases. Models of the devices were virtually deployed into the anatomical models. Experimental aneurysms were assigned to either a “complete” occlusion group if completely occluded at 4 weeks follow up, or to an “incomplete” occlusion group if still open at 8 weeks. Similarly, clinical cases were classified as “complete” occlusions if completely occluded at 3 months, or as “incomplete” occlusions if still patent at 6 months. Flow variables were then statistically compared between these groups for both the experimental and clinical series, and the predictive power of different variables to discriminate between aneurysms in each group was assessed by calculating the area under the receiving operating characteristics curves. Results: In the clinical (experimental) series, the aneurysm inflow rate was 4.02 (3.29) times larger in the incomplete occlusion group than in the completely occluded group, p=0.0210 (0.0239). Similarly, the mean aneurysm velocity was 2.75 (2.29) times larger, p=0.0044 (0.0582), and the shear rate was 1.57 (1.78) times larger, p=0.0210 (0.0722). Inflow rate could discriminate complete and incomplete occlusions with a 77% (90%) accuracy in the clinical (experimental) series. Similarly, mean velocity had a predictive power of 84% (83%) and shear rate of 76% (76%) in the clinical and experimental series. Conclusions: Flow conditions created immediately after treatment, in particular aneurysm inflow rate and mean aneurysm velocity, can prognosticate the future occlusion of aneurysms treated with flow diverters.

AbstractModeling the flow dynamics in cerebral aneurysms after the implantation of intrasaccular devices is important for understanding the relationship between flow conditions created immediately posttreatment and the subsequent outcomes. This information, ideally available a priori based on computational modeling prior to implantation, is valuable to identify which aneurysms will occlude immediately and which aneurysms will likely remain patent and would benefit from a different procedure or device.In this report, a methodology for modeling the hemodynamics in intracranial aneurysms treated with intrasaccular flow diverting devices is described. This approach combines an image‐guided, virtual device deployment within patient‐specific vascular models with an immersed boundary method on adaptive unstructured grids. A partial mesh refinement strategy that reduces the number of mesh elements near the aneurysm dome where the flow conditions are largely stagnant was compared with the full refinement strategy that refines the mesh everywhere around the device wires.The results indicate that using the partial mesh refinement approach is adequate for analyzing the posttreatment hemodynamics, at a reduced computational cost. The results obtained on a series of four cerebral aneurysms treated with different intrasaccular devices were in good qualitative agreement with angiographic observations.Promising results were obtained relating posttreatment flow conditions and outcomes of treatments with intrasaccular devices, which need to be confirmed on larger series.

Abstract BACKGROUND The safety of Pipeline TM Embolization Device (PED; Medtronic Inc, Dublin, Ireland) in posterior circulation aneurysms is still controversial. OBJECTIVE To study complications associated with the treatment of posterior circulation aneurysms by conducting a subgroup analysis from the International Retrospective Study of PED registry. METHODS Data from 91 consecutive patients with 95 posterior circulation aneurysms at 17 centers between July 2008 to February 2013 were analyzed. The primary endpoint was defined as any complication leading to neurological morbidity or death. The outcome predictors were calculated using Kaplan–Meier and Cox regression methods. RESULTS The mean aneurysm size was 13.8 mm. Aneurysm types were saccular (36.8%), fusiform (29.5%), dissecting (28.4%), and others (5.3%). The median follow-up was 21.1 mo. Twelve (13.2%) patients encountered a primary endpoint event. In multivariate analysis for the primary endpoint, use of ≥3 PEDs and fusiform shape compared with other shapes had hazard ratios (HRs) of 7.77 (95% confidence interval [CI], 2.48-25.86; P = .0007) and 3.48 (95% CI, 1.06-13.39; P = .0488), respectively. The multivariate HR of aneurysm size for neurological morbidity after PED implantation was 1.11 (95% CI, 1.04-1.18; P = .0015), and HRs of ruptured aneurysm and age for neurological mortality were 8.1 (95% CI, 1.31-41.26; P = .0197) and 1.07 (95% CI, 1.02-1.15; P = .0262), respectively. Basilar artery aneurysm had an HR of 3.54 (95% CI, 1.12-14.18, P = .0529) in the univariate analysis for major outcomes. CONCLUSION PED implantation may be considered for the treatment of posterior circulation aneurysms, especially of saccular or dissecting type. Our major complications appear to be comparable to those reported previously after clipping and coiling in the literature. Neurointerventionists should consider the shape, size, rupture, and location of complex posterior circulation aneurysms as well as age and PED number before the PED placement.

OBJECTIVEThe authors performed a pooled analysis of 3 studies—IntrePED (International Retrospective Study of the Pipeline Embolization Device), PUFS (Pipeline for Uncoilable or Failed Aneurysms Study), and ASPIRe (Aneurysm Study of Pipeline in an Observational Registry)—in order to assess angiographic outcomes and clinical safety of the Pipeline embolization device (PED).METHODSIntrePED was a retrospective study, while PUFS and ASPIRe were prospective studies. For each patient included in these studies, the authors collected baseline demographic data, aneurysm characteristics, and procedural details. The primary outcomes for this combined analysis were clinical outcomes, including neurological morbidity and mortality and major ipsilateral intracranial hemorrhage and ischemic stroke. The secondary outcomes were angiographic occlusion rates, which were available for ASPIRe and PUFS only.RESULTSA total of 1092 patients with 1221 aneurysms were included across the 3 studies. The mean aneurysm size was 12.0 ± 7.8 mm and the mean neck size was 6.6 ± 4.8 mm. The major ipsilateral ischemic stroke rate was 3.7% (40/1091). The major ipsilateral intracranial hemorrhage rate was 2.0% (22/1091). The major neurological morbidity rate was 5.7% (62/1091). The neurological mortality rate was 3.3% (36/1091). The combined major morbidity and neurological mortality rate was 7.1% (78/1091). The complete occlusion rates were 75.0% at 180 days (111/148) and 85.5% at 1 year (94/110). The overall aneurysm retreatment rate was 3.0% (33/1091) at a mean follow-up time of 10.2 ± 10.8 months.CONCLUSIONSEndovascular treatment of intracranial aneurysms with the PED is safe and effective. Angiographic occlusion rates progressed with follow-up. Rates of stroke, hemorrhage, morbidity and mortality, and retreatment were low, especially given the fact that the aneurysms treated were generally large and wide necked.