Combined technique versus stent-retriever alone: Interaction analysis of angioarchitectural and technical features

We aimed to explore if anatomical and technical features could interact and favor the chances of reperfusion according to the treatment strategy: combined technique (CoT) of mechanical thrombectomy (MT) with contact aspiration and stent-retriever (SR) versus SR alone.

Retrospective analysis of a prospective MT database for carotid terminus or MCA-M1 occlusion, first-line SR alone or CoT, and angiographic run with SR deployed on the first pass. The primary analysis involved the interaction between clinical and angiographic characteristics and first-line MT modality on first-pass effect (FPE; first pass eTICI2c-3).

A total of 300 consecutive patients were included (SR alone, n = 210 vs CoT, n = 90). Baseline characteristics as well as baseline ASPECTS, CTA collateral score, clot burden score, FPE were similar amongst groups. Anatomical and technical variables (presence of reperfusion channel, frequency of SR position in dominant MCA division, angle of device-clot interaction, and clot length) were comparable between groups, with exception of SR opening (diameter across the occlusion) and length of SR purchase beyond the clot being more pronounced in the SR group. None of the clinical, anatomical, and technical factors were found to have an interaction with the MT strategy on the chances of FPE (P-interaction ≥ 0.001). Multivariable logistic regression showed that clot burden score ≥8 (aOR 3.02, P = 0.003), angle of interaction (aOR 1.01, P = 0.015) but not the MT modality were associated with FPE.

No specific anatomical or technical features were observed to predispose to benefit when combining contact aspiration and SR thrombectomy. Clot burden score ≥ 8 and angle of interaction were independent factors associated with FPE. Additional studies are warranted.