Real-World Device Selection for Endovascular Treatment with Adjunctive Techniques in Ruptured Intracranial Aneurysms: Insights from the Japanese Registry of Neuroendovascular Therapy (JR-NET) 4

Abstract Purpose This study investigated the characteristics and clinical outcomes of adjunctive technique-assisted endovascular treatment (EVT) for ruptured intracranial aneurysms (RIAs) using data from the Japanese Registry of Neuroendovascular Therapy 4. Methods 3,611 EVTs were categorized into double-microcatheter coil embolization (DMC), balloon-assisted coil embolization (BAC), and stent-assisted coil embolization/flow diverter (SAC/FD). Patient characteristics, aneurysm morphology, intraoperative findings, complications, antithrombotic therapies, and 30-day modified Rankin Scale (mRS) scores were compared. Results 703 DMC, 2,216 BAC, and 691 SAC/FD procedures were analyzed. Large/wide-necked RIAs comprised 63.9%. SAC/FD was primarily used for non-saccular and posterior circulation aneurysms, BAC for internal carotid artery aneurysms, and DMC for middle cerebral/anterior communicating artery aneurysms. The technical success rate was 99.6%. Intraprocedural rupture was highest in BAC (4.7%), and thromboembolism was slightly higher in SAC/FD (6.5%, p = 0.18). Postoperative complication rates were similar. Preoperative multiple antiplatelet therapy was more frequent in SAC/FD (61.6%, p < 0.001). Favorable outcomes (mRS 0–2) were achieved in 53.8%, with no significant mortality (9.4%) or overall outcome differences. Conclusion This study analyzed real-world trends in adjunctive technique-assisted EVT for RIAs in Japan. BAC was the most common technique, while DMC and SAC/FD were selectively used based on aneurysm morphology and location. These findings provide insights into optimal device selection and may help reduce procedure-specific complications in EVT for RIAs. Trial registration number and date: C20-04-001 (retrospectively registered). May 1, 2020.