ABSTRACT NUMBER: ESOC2026A1783 PILOT IN VITRO STUDY OF SERIAL DOUBLE STENT RETRIEVERS FOR EMBOLIC TANDEM TERMINAL ICA–M1 OCCLUSION

Abstract Background and aims Embolic tandem occlusion involving the terminal internal carotid artery (ICA) and the M1 segment of the middle cerebral artery can create a large clot burden at separated sites, limiting first-pass reperfusion with a single stent retriever (SR). We evaluated a technique using two SRs deployed in series. Methods Tandem occlusions were created in an in vitro neurovascular model. Clot analogs with red blood cell fractions ranging from 25% to 90% were used and were allocated approximately 1:1 to soft and stiff consistency. In the double-SR technique, two SRs (6 × 40 mm in the ICA and 4 × 40 mm in M1) were deployed and retrieved simultaneously, whereas the single-SR technique used a one 4 × 40 mm SR in M1. Both techniques were performed with adjunct aspiration using a 0.071-inch aspiration catheter. Outcomes were procedural feasibility and the rate of first-pass complete reperfusion with no distal emboli ≥1 mm captured in the downstream filter. Results Fourteen pilot experiments were performed (double-SR, n = 7; single-SR, n = 7). Technical success was achieved in all cases. The rate of first-pass complete reperfusion was higher with double-SR than with single-SR (4/7 [57%] vs. 1/7 [14%]). Conclusions Serial double-SR retrieval appears technically feasible. The rate of first-pass complete reperfusion tended to be higher with double-SR than with single-SR. A larger randomized series (20 per group) is ongoing to clarify potential mechanical advantages of the double-SR strategy. Conflict of interest Yuki Yamamoto. nothing to disclose.