Abstract DP172: Pipeline Flex-Shield™ Embolization Device 60 Day Dual Antiplatelet Therapy (DAPT) Followed by 305 Day Aspirin Early Feasibility Study (EFS) 1 Year Study

Introduction: Flow-diverting stents traditionally require dual antiplatelet therapy (DAPT) to prevent thromboembolic complications, though DAPT is associated with high hemorrhagic risk (up to 27%). The Pipeline™ Flex Embolization Device with Shield Technology™ incorporates a phosphorylcholine polymer (<3 nm) to reduce thrombogenicity, with in vitro data demonstrating lower thrombin generation and platelet activation. Early clinical experience, including 15 ruptured aneurysms treated with aspirin alone, suggests PED Shield may allow safe use with reduced or single antiplatelet therapy. Methods: A prospective, single arm, open label EFS was conducted to evaluate the safety and preliminary effectiveness of PED Shield with reduced duration of DAPT (60 days). Ten patients were enrolled and monitored by a DSMB for safety. All received 60 days of DAPT with aspirin (325 mg) and clopidogrel (75 mg); clopidogrel non-responders (P2Y12 > 200) received ticagrelor (90 mg BID) instead. After 60 days, DAPT will transition to lifelong aspirin monotherapy. Results: Ten patients (median age 60.5 years; 8 female, 9 White) with baseline mRS 0 underwent endovascular treatment of intracranial aneurysms. Locations included superior hypophyseal (n=3), posterior communicating (n=3), ophthalmic (n=2), cavernous ICA (n=1), and dorsal ICA (n=1); median dome and neck diameters were 4.2 mm and 3.1 mm. Four aneurysms had blebs, and three showed dome-branch incorporation. Procedures were performed under conscious sedation with balloon guide catheter (n=3) or triaxial system (n=4); median groin-to-deployment and total procedural times were 36 and 48 minutes. Immediate post-deployment angiography showed complete occlusion in all cases. Post-procedural MRI revealed new clinically silent DWI lesions in 2 patients. During follow-up (median 377 days), two ischemic events occurred: one transient ischemic attack and one minor stroke; no in-stent thrombosis or alternative etiology was found. Remaining patients maintained mRS 0. At median angiographic follow-up of 367 days, seven aneurysms were fully occluded, two had neck remnants, and one remained unoccluded. Among seven patients with 12-month DSA, six showed complete occlusion. Conclusion: Preliminary results suggest early promise for discontinuing DAPT at 60 days following PED Shield placement. The study is now accelerating enrollment to expand the cohort and strengthen evidence supporting early DAPT cessation.