RT Journal Article SR Electronic T1 P137/17  Incidence and outcome of perforations occuring during Medium-Vessel Occlusion thrombectomy compared to Large-Vessel occlusion thrombectomy JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP A67 OP A67 DO 10.1136/jnis-2023-ESMINT.165 VO 15 IS Suppl 2 A1 Schulze-Zachau, Victor A1 Brehm, Alex A1 Ntoulias, Nikolaos A1 Krug, Nadja A1 Tsogkas, Ioannis A1 Blackham, Kristine A1 Möhlenbruch, Markus A1 Jesser, Jessica A1 Cervo, Amedeo A1 Kreiser, Kornelia A1 Althaus, Katharina A1 Maslias, Errikos A1 Michel, Patrik A1 Saliou, Guillaume A1 Riegler, Christoph A1 Nolte, Christian A1 Maier, Ilko A1 Jamous, Ala A1 Rautio, Riitta A1 Ylikotila, Pauli A1 Fargen, Kyle A1 Wolfe, Stacey A1 Castellano, Davide A1 Boghi, Andrea A1 Kaiser, Daniel A1 Cuberi, Ani A1 Kirschke, Jan A1 Schwarting, Julian A1 Limbucci, Nicola A1 Renieri, Leonardo A1 Kasab, Sami Al A1 Spiotta, Alejandro A1 Fragata, Isabel A1 Rodríguez-Ares, Tania A1 Maurer, Christoph A1 Ansgar, Berlis A1 Moreu, Manuel A1 López-Jurado, Alfonso López-Frías A1 Pérez-García, Carlos A1 Commodaro, Christian A1 Pileggi, Marco A1 Mascitelli, Justin A1 Giordano, Flavio A1 Casagrande, Walter A1 Purves, Cynthia A1 Bester, Maxim A1 Flottmann, Fabian A1 Kan, Peter A1 Edhayan, Gautam A1 Hofmeister, Jeremy A1 Machi, Paolo A1 Kaschner, Marius A1 Weiss, Daniel A1 Katan, Mira A1 Fischer, Urs A1 Psychogios, Marios YR 2023 UL http://jnis.bmj.com/content/15/Suppl_2/A67.1.abstract AB Introduction Vessel perforation during thrombectomy is a severe complication and is hypothesized to be more frequent during MeVO compared to LVO thrombectomy.Aim of the study To compare the incidence and outcome of patients with perforation during MeVO and LVO thrombectomy and to report on the procedural steps that led to perforation.Methods In this multicenter retrospective cohort study, data of consecutive patients with vessel perforation during thrombectomy between January 01, 2015 and September 30, 2022 were collected. The primary outcomes were independent functional outcome (i.e. modified Rankin Scale 0–2) and all-cause mortality at 90 days. Binomial test, chi-squared test and t-test for unpaired samples were used for statistical analysis.Results During 25,769 thrombectomies (5,124 MeVO, 20,645 LVO) in 25 stroke centers, perforation occurred in 335 patients (1.3%; mean age 72 years, 62% female). Perforation occurred more often in MeVO thrombectomy (2.4%) than in LVO thrombectomy (1.0%, p < 0.001). More MeVO than LVO patients with perforation achieved functional independence at three months (25.7% vs 10.9%; p=0.001). All-cause mortality did not differ (overall 51.6%). Navigation beyond the occlusion and retraction of stent-retriever/aspiration catheter were the two most common procedural steps that led to perforation.Conclusions In our cohort, perforation was approximately twice as frequent in MeVO than in LVO thrombectomy. Considering the rather benign natural course of MeVO stroke, physicians should be avoiding perforation during MeVO thrombectomy by all means. Efforts to optimize the procedure may focus on navigation beyond the occlusion site and retraction of stent-retriever/aspiration catheter.Disclosure of Interest Nothing to disclose