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.
Yamamoto et al. (Fri,) studied this question.