ABSTRACT NUMBER: ESOC2026A2098 ACCESS-SITE COMPLICATIONS ARE ASSOCIATED WITH WORSE CLINICAL OUTCOME AFTER MECHANICAL THROMBECTOMY – A RETROSPECTIVE ANALYSIS OF THE GERMAN STROKE REGISTRY

Abstract Background and aims Access-site complications (ASC) are recognized adverse events following endovascular procedures. Their impact on clinical outcomes after mechanical thrombectomy (MT) in patients with acute ischemic stroke remains incompletely understood. Methods We conducted a retrospective analysis of the German Stroke Register including patients treated between 2015 and 2021. Overall, 12,842 patients undergoing MT or experiencing neurological deterioration were identified. Due to missing data, the final comparative analysis was performed using propensity-score matching in R Studio, including 563 patients with access-site complications and 563 matched controls without complications. Matching was based on demographic variables, treatment center, vascular risk factors, premedication, baseline clinical severity, imaging characteristics, and acute stroke treatment parameters. Results Access-site complications occurred in 720 patients overall. In the propensity-score–matched cohort, no significant differences were observed between patients with and without ASC regarding length of hospital stay or NIHSS at discharge. A favorable functional outcome (modified Rankin Scale [mRS] 0–3) was observed less frequently in patients with ASC compared to controls at discharge (9.8% vs. 18.3%), whereas poor outcome (mRS 4–6) was more common in patients with ASC (40.6% vs. 31.3%; p < 0.001). At 90 days, favorable functional outcome remained significantly less frequent in patients with ASC (12.0% vs. 22.1%), while poor outcome occurred more often (38.4% vs. 27.5%; p < 0.001). Conclusions Access-site complications after MT were independently associated with worse short- and mid-term functional outcomes. These findings underscore the clinical importance of strategies aimed at preventing access-site complications to improve long-term outcomes after mechanical thrombectomy. Conflict of interest All authors have nothing to disclose