OBJECTIVE: The aim of this study was to evaluate the morbidity associated with microsurgical treatment in patients with a recurrent aneurysm to improve their surgical management.
METHODS: From 2012 to 2022, among the 3128 patients with ruptured or unruptured intracranial aneurysms managed at the authors\' institution, 954 patients were treated by a microsurgical procedure. Of these 3128 patients, 60 consecutive patients (6.3%) who had a recurrent microsurgically treated aneurysm after previous endovascular treatment were included in this study. Additional microsurgical treatment was considered in case of progressive remnant growth or significant aneurysm recurrence. Intraoperative and postoperative complications were noted. Early (< 7 days) and long-term clinical and radiological monitoring were performed. Good functional outcome was considered as a modified Rankin Scale score < 3.
RESULTS: The mean age at initial treatment was 45 years (range 26-65 years). The mean delay between the first treatment and microsurgical treatment of the recurrence was 64 months (range 2 days-296 months). The mean size of the fundus recurrence was 5 mm, and the mean size of the neck recurrence was 4.6 mm. Five patients (8.3%) presented with subarachnoid hemorrhage associated with rupture of the recurrent aneurysm. Three patients died (6%) of aneurysm rupture and/or intensive care complications. The total morbidity rate associated with the microsurgical procedure was 14.5% (8/55) in patients with unruptured recurrent aneurysms. Among these patients, postoperative definitive complications (ischemic lesions) directly related to the microsurgical procedure were present in 3 patients (5.5%). Intraoperative rupture was recorded in these 3 patients. In the 54 surviving patients with unruptured recurrent aneurysms, good functional outcome was noted in 49 (91%). Poor functional outcome was significantly associated with intraoperative rupture.
CONCLUSIONS: Microsurgery remains an effective therapeutic option for recurrent intracranial aneurysms. However, in the authors\' experience, postoperative morbidity is higher than in patients with nonrecurrent aneurysms. Therefore, a pretherapeutic multidisciplinary evaluation is mandatory to reduce the potential morbidity associated with the retreatment as much as possible. When endovascular occlusion of the aneurysm requires both stenting and coiling, alternative microsurgical treatment should be carefully evaluated, as microsurgical clipping will become much more challenging in cases of aneurysm recurrence.

OBJECTIVE: The efficacy of endovascular thrombectomy in patients with posterior circulation ischemic stroke remains controversial. Early neurological deterioration (END) as an important predictor of poor outcome is poorly understood, except in cases of symptomatic intracranial hemorrhage, recanalization failure, and malignant cerebral edema. The objective of this study was to assess predictors of unexplained END (UnEND) after endovascular thrombectomy.
METHODS: The BASILAR study is a multicenter prospective observational study in which 647 patients with vertebrobasilar occlusion on imaging within 24 hours of stroke onset and who underwent endovascular treatment were enrolled, of whom 477 who had undergone successful recanalization were included in this study. Multivariate analysis was used to identify the predictors of UnEND, defined as a ≥ 4-point increase in National Institutes of Health Stroke Scale (NIHSS) score at 24 hours after endovascular thrombectomy.
RESULTS: Among the 477 eligible patients included, UnEND occurred in 86 (18%) patients. The predictors of UnEND were stress hyperglycemic ratio (SHR) (OR 2.2, 95% CI 1.1-4.6; p = 0.031), baseline NIHSS score (OR 0.9, 95% CI 0.83-0.95; p = 0.001), and asymptomatic intracerebral hemorrhage (aICH) (OR 5.9, 95% CI 1.7-20.0; p = 0.004). The occurrence rate of a favorable outcome, defined as a modified Rankin Scale score of 0-2 at 90 days, was lower in the UnEND group (5.8% vs 47.6%, p < 0.001) compared with the group without END, and the UnEND group had higher mortality at 90 days (66.3% vs 27.4%, p < 0.001).
CONCLUSIONS: UnEND may be associated with poor outcome after endovascular thrombectomy in patients with acute vertebrobasilar occlusion. Some modifiable factors such as SHR and aICH could be targeted to improve the efficacy of endovascular thrombectomy.

OBJECTIVE: Previous randomized controlled trials have reported a significantly higher occlusion rate of large and giant aneurysms when utilizing the Tubridge flow diverter (FD). In the present trial, the safety and efficacy of the Tubridge FD in treating unruptured internal carotid artery (ICA) or vertebral artery (VA) aneurysms were assessed in a real-world setting.
METHODS: The Intracranial Aneurysms Managed by Parent Artery Reconstruction Using Tubridge Flow Diverter (IMPACT) study is a prospective, multicenter, single-arm clinical trial assessing the efficacy of the Tubridge FD in the management of unruptured aneurysms located in the ICA or VA. The primary endpoint was the complete occlusion (Raymond-Roy class 1) rate at the 1-year follow-up. The secondary endpoints included the technical success rate, the successful occlusion rate of the aneurysm, which is the degree of aneurysm embolization scored as Raymond-Roy class 1 or 2, major (> 50%) in-stent stenosis, and incidence of disabling stroke or neurological death associated with the target aneurysms.
RESULTS: This study included 14 interventional neuroradiology centers, with 200 patients and 240 aneurysms. According to angiographic core laboratory assessment, 205 (85.4%) aneurysms were located in the ICA, 34 (14.2%) in the VA, and 1 (0.4%) in the middle cerebral artery. Additionally, 189 (78.8%) aneurysms were small (< 10 mm). At the 12-month follow-up, the total occlusion rate was 79.0% (166/210, 95% CI 72.91%-84.34%). Additionally, the occurrence of disabling stroke or neurological death related to the specified aneurysms was 1% (2/200).
CONCLUSIONS: The 1-year results from the IMPACT trial affirm the safety record of use of the Tubridge FD in the treatment of intracranial aneurysms in real-world scenarios. These results reveal low morbidity and mortality rates of 3.5% and 1.5%, respectively. Furthermore, they provide evidence of the effectiveness of the Tubridge FD, as demonstrated by the complete occlusion achieved in 166 of 210 (79%) cases.

OBJECTIVE: The placement of flow-diverting devices has become a common method of treating unruptured intracranial aneurysms of the internal carotid artery. The progressive improvement of aneurysm occlusion after treatment-with low complication and rupture rates-has led to a dilemma regarding the management of aneurysms in which occlusion has not occurred within 6-24 months. The authors aimed to identify clinical consensus regarding management of intracranial aneurysms displaying persistent filling 6-24 months after flow diversion and to ascertain questions that may drive future investigation.
METHODS: An international panel of 67 experts was invited to participate in a multistep Delphi consensus process on the treatment of intracranial aneurysms after failed flow diversion.
RESULTS: Of the 67 experts invited, 23 (34%) participated. Qualitative analysis of an initial survey with open-ended questions resulted in 51 statements regarding management of aneurysms showing persistent filling after flow diversion. The statements were grouped into 8 categories, and in the second round, respondents rated the degree of their agreement with each statement on a 5-point Likert scale. Flow diverters with surface modifiers did not influence administration of dual-antiplatelet therapy according to 83%. Consensus was also reached regarding the definition of treatment failure at specific time points, including at 6 months if there is aneurysm growth or persistent rapid flow through the entirety of the aneurysm (96%), at 12 months if there is aneurysm growth or symptom onset (78%), and at 24 months if there is persistent filling regardless of size and filling characteristics (74%). Although experts agreed that the degree of intimal hyperplasia or in-device stenosis could not be ascertained by noninvasive imaging alone (83%), only 65% chose digital subtraction angiography as the preferred modality. At 6 and 12 months, retreatment is preferred if there is persistent filling with aneurysm growth (96%, 96%), device malposition (48%, 87%), or a history of subarachnoid hemorrhage (65%, 70%), respectively, and at 24 months if there is persistent filling without reduction in aneurysm size (74%). Experts favored treatment with an additional flow diverter (87%) over aneurysm clipping, applying the same principles for follow-up (83%) and treatment failure (91%) as for the first flow diverter.
CONCLUSIONS: The authors present the consensus practices of experts in the management of intracranial aneurysms without occlusion 6-24 months after treatment with a flow-diverting device.

OBJECTIVE: The number of cerebrovascular (CV) surgeons has grown with the rise of endovascular neurosurgery. However, it is unclear whether the number of CV surgeon-scientists has concomitantly increased. With increasing numbers of CV neurosurgeons in the US workforce, the authors analyzed associated changes in National Institutes of Health (NIH) and Neurosurgery Research and Education Foundation (NREF) funding trends for CV surgeons over time.
METHODS: Publicly available data were collected on currently practicing academic CV surgeons in the US. Inflation-adjusted NIH funding between 2009 and 2021 was surveyed using NIH RePORTER and Blue Ridge Institute for Medical Research data. The K12 Neurosurgeon Research Career Development Program and NREF grant data were queried for CV-focused grants. Pearson R correlation, chi-square analysis, and the Mann-Whitney U-test were used for statistical analysis.
RESULTS: From 2009 to 2021, NIH funding increased: in total (p = 0.0318), to neurosurgeons (p < 0.0001), to CV research projects (p < 0.0001), and to CV surgeons (p = 0.0018). During this time period, there has been an increase in the total number of CV surgeons (p < 0.0001), the number of NIH-funded CV surgeons (p = 0.0034), and the percentage of CV surgeons with NIH funding (p = 0.370). Additionally, active NIH grant dollars per CV surgeon (p = 0.0398) and the number of NIH grants per CV surgeon (p = 0.4257) have increased. Nevertheless, CV surgeons have been awarded a decreasing proportion of the overall pool of neurosurgeon-awarded NIH grants during this time period (p = 0.3095). In addition, there has been a significant decrease in the number of K08, K12, and K23 career development awards granted to CV surgeons during this time period (p = 0.0024). There was also a significant decline in the proportion of K12 (p = 0.0044) and downtrend in early-career NREF (p = 0.8978) grant applications and grants awarded during this time period. Finally, NIH-funded CV surgeons were more likely to have completed residency less recently (p = 0.001) and less likely to have completed an endovascular fellowship (p = 0.044) as compared with non-NIH-funded CV surgeons.
CONCLUSIONS: The number of CV surgeons is increasing over time. While there has been a concomitant increase in the number of NIH-funded CV surgeons and the number of NIH grants awarded per CV surgeon in the past 12 years, there has also been a significant decrease in CV surgeons with K08, K12, and K23 career development awards and a downtrend in CV-focused K12 and early-career NREF applications and awarded grants. The latter findings suggest that the pipeline for future NIH-funded CV surgeons may be in decline.

OBJECTIVE: The recent introduction of the Woven EndoBridge (WEB) has presented an alternative treatment modality for intracranial bifurcation and wide-neck aneurysms with a growing body of literature evaluating its efficacy. However, no previous systematic review has focused on comparing WEB with previously using endovascular approaches, specifically primary coiling (PC) and stent-assisted coiling (SAC). Herein, the authors present the first systematic review summarizing available literature to reach a consensus regarding the safety and effectiveness of WEB.
METHODS: A systematic review of articles identified through a search of PubMed, Embase, Scopus, and Web of Science was conducted. Studies were included if they compared WEB with PC or SAC from any aspect for intracranial aneurysms. Risk of bias was assessed using the Risk of Bias in Non-Randomized Studies-of Interventions tool. Meta-analyses of the outcomes based on stent use and rupture status were performed.
RESULTS: A total of 16 studies were included. The three endovascular approaches were comparable in terms of baseline characteristics except for older age and smaller aneurysm neck in the PC group (p < 0.05). Moreover, the follow-up duration was shorter in the WEB group (p < 0.05). Although the WEB group demonstrated lower complete and adequate immediate occlusion rates (p < 0.01), the rates at follow-up evaluations were comparable with SAC and PC (p = 0.61 and p = 0.27, respectively). The WEB group experienced significantly fewer unfavorable neurological outcomes than the SAC group (p = 0.04), while comparable to the PC group (p = 0.36). Retreatment rates were comparable between WEB and coiling (p = 0.92). The WEB group had fewer hemorrhagic and thromboembolic complications (p < 0.01 and p = 0.01, respectively), with similar neurological and procedure-related complications compared with combined PC and SAC groups. Lastly, mortality was comparable among the different endovascular approaches.
CONCLUSIONS: This study provides evidence on the noninferiority of WEB compared with PC and SAC in terms of angiographic outcomes. Meanwhile, our findings on lower complication rates, cost, and improved operative aspects associated with WEB establish this novel endovascular treatment as a safe and effective alternative for the treatment of bifurcation and wide-neck aneurysms.

OBJECTIVE: Heparin-induced thrombocytopenia is a known complication of heparin exposure with potentially life-threatening sequelae. Direct thrombin inhibitors can be substituted for heparin in patients with heparin-induced thrombocytopenia that require anticoagulation. However, the use of direct thrombin inhibitors as a substitute for heparin has not been widely reported in the neuroendovascular literature.
METHODS: Here we report the first use of the direct thrombin inhibitor bivalirudin in a neuroendovascular procedure as a substitute for heparin in a patient with a ruptured pseudoaneurysm and heparin-induced thrombocytopenia, and review the literature on the use of bivalirudin and argatroban for such patients.
RESULTS: Bivalirudin was safely and effectively used in the case reported, with no thrombotic or hemorrhagic complications. Our literature review revealed a paucity of studies on the use of heparin alternatives, including bivalirudin, in neuroendovascular procedures in patients with heparin-induced thrombocytopenia.
CONCLUSIONS: Heparin-induced thrombocytopenia is an important iatrogenic disease process in patients undergoing neuroendovascular procedures, and developing protocols to diagnose and manage heparin-induced thrombocytopenia is important for healthcare systems. While further research needs to be done to establish the full range of anticoagulation options to substitute for heparin, our case indicates bivalirudin as a potential candidate.

OBJECTIVE: Intracranial aneurysms (IAs) pose a significant health risk, often leading to subarachnoid hemorrhage and severe neurological outcomes. Endovascular coiling has been a principal treatment method, but it comes with the challenge of high recanalization rates. Aspirin has recently emerged as a potential agent to reduce these rates. In this study, the authors aimed to investigate the impact of regular aspirin use on aneurysm recanalization rates following endovascular coiling in a 10-year single-institution study.
METHODS: A retrospective analysis was conducted on a dataset of 2236 aneurysms treated by a single neurosurgeon over a period of 10 years. The primary outcome measure was aneurysm recanalization, defined by a change in the Raymond-Roy Occlusion Classification of at least one grade.
RESULTS: A total of 525 aneurysms were coiled, 109 of which involved patients who reported regular use of aspirin. The recanalization rate was significantly lower in the aspirin group (9.2%) compared with the control group (23.6%) (OR 0.33, 95% CI 0.15-0.66; p = 0.001). On analysis of the specific mechanisms of recanalization, aneurysm sac growth was less frequent in the aspirin group (5.5%) compared with the control group (18%) (OR 0.265, 95% CI 0.09-0.63; p = 0.002). Additionally, patients in the control group had a higher retreatment rate (18%) than patients in the aspirin group (5.5%) (OR 0.265, 95% CI 0.09-0.63; p = 0.002).
CONCLUSIONS: Regular use of aspirin appears to be associated with reduced rates of aneurysm recanalization after endovascular coiling. However, caution is advised in interpretation of these results given the retrospective nature of this study. Further randomized controlled trials are needed to confirm these findings.

OBJECTIVE: Malignant cerebral edema (MCE) is a life-threatening complication of ischemic stroke. Few studies have evaluated MCE in patients with acute basilar artery occlusion (BAO) receiving endovascular treatment (EVT). Therefore, the authors investigated the incidence, predictors, and functional outcomes of MCE in BAO patients undergoing EVT.
METHODS: This was a post hoc analysis of the Endovascular Treatment for Acute Basilar Artery Occlusion (ATTENTION) trial, a prospective, randomized, multicenter clinical trial that compared endovascular treatment with conventional care of patients with BAO at 36 centers in China. Brain edema was retrospectively assessed using the Jauss score for all available follow-up scans, and patients with a Jauss score ≥ 4 were classified as having MCE. Clinical functional independence was defined as a modified Rankin Scale (mRS) score of 0-2, and a good outcome was defined as an mRS score of 0-3 at the 90-day follow-up. Univariate and multivariate analyses were used to explore the predictors of MCE and the impact of MCE on prognosis.
RESULTS: A total of 189 patients were analyzed, and 13.2% of patients developed MCE. Multivariate analysis showed that the baseline Glasgow Coma Scale (GCS) score (OR 0.722, 95% CI 0.548-0.950; p = 0.020) and the number of procedures (OR 1.594, 95% CI 1.051-2.419; p = 0.028) were significantly associated with MCE. After adjusting for confounding factors, the presence of MCE was significantly associated with a lower rate of functional independence (OR 0.115, 95% CI 0.023-0.563; p = 0.008), a lower rate of good outcome (OR 0.092, 95% CI 0.023-0.360; p = 0.001), and a higher rate of mortality (OR 5.373, 95% CI 2.055-14.052; p = 0.001) at the 90-day follow-up.
CONCLUSIONS: MCE is not uncommon in BAO patients undergoing EVT and is associated with poor outcomes. Baseline GCS score and the number of procedures were predictors of MCE. In clinical practice, it is crucial that physicians identifying MCE after EVT in patients with BAO and identification of MCE will help in the selection of an appropriate pharmacological treatment strategy and close monitoring.

OBJECTIVE: The benefit-to-risk ratio of periprocedural heparin in patients treated with endovascular thrombectomy (EVT) after intravenous thrombolysis (IVT) remains unclear. This study aimed to evaluate the potential effects of periprocedural heparin on clinical outcomes of EVT after IVT.
METHODS: The authors retrospectively analyzed patients from multicenter studies treated with EVT after IVT in the anterior circulation. The endpoints were unfavorable outcome (defined as modified Rankin Scale score ≥ 3 at 90 days), 90-day mortality, symptomatic intracranial hemorrhage (SICH), successful recanalization, and early neurological deterioration. Patients were divided into two groups based on whether they were treated with heparin (heparin-treated group) or not (untreated group), and the efficacy and safety outcomes were compared using multivariable logistic regression models and propensity score-matching methods.
RESULTS: Among the 322 included patients (mean age 67.4 years, 54.3% male), 32% of patients received periprocedural heparin. In multivariable analyses, the administration of periprocedural heparin was a significant predictor for unfavorable outcome (OR 2.821, 95% CI 1.15-7.326; p = 0.027), SICH (OR 24.925, 95% CI 2.363-780.262; p = 0.025), and early neurological deterioration (OR 5.344, 95% CI 1.299-28.040; p = 0.029). Regarding successful recanalization and death, no significant differences between the groups were found after propensity score matching.
CONCLUSIONS: The results showed that periprocedural heparin is associated with an increased risk of unfavorable outcomes and SICH in patients treated with EVT after IVT. Further studies are warranted to evaluate the utility and safety of periprocedural heparin.