ABSTRACT NUMBER: ESOC2026A185 INTRACRANIAL PROCEDURAL COMPLICATIONS IN ENDOVASCULAR AND NEUROSURGICAL TREATMENT OF RUPTURED INTRACRANIAL ANEURYSMS – A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Background and aims The risk of intracranial procedural complications during endovascular (EVT) and neurosurgical treatment (NST) of ruptured intracranial aneurysms varies across studies, making risk estimation difficult. We aimed to provide an overview of the types of procedural complications for both EVT and NST and their proportions. Methods PubMed, Embase, and Cochrane were searched for studies published between 2014 and January 1, 2024, that included ≥ 30 patients undergoing EVT or NST for a ruptured intracranial aneurysm and reported intracranial procedural complications. For both EVT and NST separately, we used a random-effects model based on a binomial generalized linear mixed model to provide pooled proportions with 95% confidence intervals of each complication type. Results We included 152 studies (69,846 patients). Among the reported procedural complication types, the most common for EVT (118 studies; 62,127 patients) were procedure-related ischemia (6.8%, 95% CI 4.8-9.4, I2 97.0%; 45 studies; 44,403 patients) and thromboembolic events (6.2%, 95% CI 5.1-7.6, I2 82.7%; 76 studies; 11,251 patients). For NST (51 studies; 7,719 patients) the most common procedural complications were intraoperative rupture (15.4%; 95% CI 11.1-20.9, I2 91.8%; 38 studies; 5,464 patients) and procedure-related ischemia (11.7%; 95% CI 8.2-16.5, I2 92.1%; 28 studies; 4,082 patients). Conclusions In ruptured intracranial aneurysm treatment, procedural complications remain an important concern, with different complication profiles for each treatment method. These findings provide a contemporary overview of modality-specific procedural risk and underscore the importance of standardized reporting. We will analyse and report risk factors for procedural complications for both EVT and NST separately. Conflict of interest Prof. H.D. Boogaarts is consultant for Stryker Neurovascular, fees are paid to the department of neurosurgery. Charles Majoie received funds from CVON/Dutch Heart Foundation, Stryker, Boehringer Ingelheim, European Commission, and Healthcare Evaluation Netherlands (unrelated to this project; all paid to institution); P.B van Wijngaarden: nothing to disclose; R.A.J. Wijdeven: nothing to disclose; M.D.I. Vergouwen: nothing to disclose; G.J.E. Rinkel: nothing to disclose; D. Verbaan: nothing to disclose