692 Impact of Dual Antiplatelet Therapy After Stent-assisted Coiling of Unruptured Aneurysms on Risk of Complications

INTRODUCTION: Despite some consensus on the need for perioperative dual antiplatelet therapy (DAPT) after stent-assisted coiling (SAC), the ideal duration of therapy is not clear. METHODS: Ten institutions retrospectively reviewed data from databases prospectively maintained as part of a collaborative research group. Patients with unruptured intracranial aneurysms treated with DAPT following SAC (excluding flow diverters) between January 1, 2016 and December 31, 2020 with at least 6 months follow-up. Records were reviewed for type and duration of DAPT before and after SAC, type of stent, outcome (mRS), follow-up duration, peri-procedural and delayed complications, and rate of significant in-stent stenosis. Complications were considered “during period of risk” if they occurred during DAPT when short term had completed (hemorrhagic) or after completing DAPT when long term continued (thrombotic). RESULTS: 556 patients were reviewed. 450 met all inclusion criteria. Nine patients treated for fewer than 29 days after SAC and 10 treated 43-89 days were excluded from analysis. 80 were treated with short-term DAPT (30-42 days), 188 with medium term (90-179 days), and 163 with long term (180+ days). There were no significant differences in the rate of thrombotic complications during the period of risk in short (1/80; 1.25%), medium (2/188; 1.1%) or long (0/163; 0%) term groups, but rates of hemorrhagic complications were lower in the short-term group (0/80; 0%) versus medium (3/188; 1.6%) or long (1/163; 0.6%). Longer duration DAPT did not reduce the risk of in-stent stenosis (0%; 2.5%; 3.2%). CONCLUSIONS: Continuing DAPT beyond 42 days after SAC did not reduce the risk of thrombotic complications or in-stent stenosis and may increase the risk of hemorrhagic complications. It may be reasonable to discontinue DAPT after 42 days following SAC.