Clot Meniscus Sign: An Angiographic Clue for Choosing between Stent Retriever and Contact Aspiration in Acute Basilar Artery Occlusion

Abstract

Background and purpose: The efficacy of mechanical thrombectomy methods may differ depending on the characteristics of the occlusion. The purpose of this study was to compare the recanalization efficacy and treatment outcome of a stent retriever versus contact aspiration in patients with acute basilar artery occlusion according to the angiographic characteristics of the occlusion.

Materials and methods: One hundred sixty-one patients with acute basilar artery occlusion who underwent mechanical thrombectomy were retrospectively analyzed. A stent retriever was compared with contact aspiration thrombectomy according to the clot meniscus sign, defined as a meniscoid/tram-track-like sidewall contrast opacification of the thrombus. A propensity score matching analysis was performed. Clinical/angiographic characteristics and treatment and clinical outcomes were compared.

Results: Overall, a stent retriever (n = 118) and contact aspiration (n = 43) did not show significant differences in the successful recanalization (82.2% versus 86.0%) and good clinical outcome rates (32.2% versus 39.5%). In patients with the positive meniscus sign, contact aspiration was associated with shorter procedural time (44 versus 26 minutes, P = .018), a lower number of passes (2 versus 1, P = .041), a higher complete recanalization rate (58.8% versus 85.7%, P = .021), and a higher rate of first-pass effect (27.9% versus 53.6%, P = .031) compared with a stent retriever. After propensity score matching, contact aspiration was associated with higher complete recanalization rates (59.3% versus 85.7%, P = .033). No significant differences in the outcomes were noted between a stent retriever and contact aspiration in patients negative for the meniscus sign.

Conclusions: The efficacy of the mechanical thrombectomy techniques may differ according to the angiographic characteristics of occlusion in patients with basilar artery occlusion. Contact aspiration may be more effective in terms of recanalization compared with a stent retriever in patients with the clot meniscus sign.