Clinical Impact of Large Vessel Occlusion Achieved First Pass Effect with Stent Retriever Alone: A Single-Center...

The first pass effect (FPE), which means the achievement of complete or near-complete reperfusion of large vessel occlusion (LVO) in the first pass, is one of the goals of mechanical thrombectomy (MT). However, the impact of FPE on the prognosis has not been assessed for Japanese patients with various degrees of independence before the onset of LVO. The purpose of this study was to investigate the prognostic effects of FPE in a comprehensive stroke center in Japan, which includes patients in a variety of self-independence states with different comorbidities before stroke onset.

Between April 2017 and March 2020, 151 patients who underwent MT with a stent retriever (SR) alone as initial strategy for anterior circulation (internal carotid artery terminal, M1, M2) LVO at our hospital and finally achieved modified treatment in cerebral infarction (mTICI) 2b-3 were analyzed. Forty-eight patients in whom first pass mTICI 2c-3 was achieved were classified into the FPE+ group, and the other 103 patients were classified into the FPE- group. We compared the characteristics and clinical outcomes between patients with and without FPE, and estimated the odds ratio for outcomes after adjusting for confounders.

The puncture-reperfusion time was shorter (20 vs. 35 minutes; p <0.01), and cardiogenic embolism was more common (81.3 vs. 60.2%; p = 0.01) in the FPE+ group. The FPE was significantly associated with good neurological outcome after 3 months (p <0.01; adjusted odds ratio [aOR], 3.87; 95% confidence interval [CI], 1.69-9.38), reduction in all intracranial hemorrhage (p <0.01; aOR, 0.24; 95% CI, 0.10-0.54), and symptomatic intracranial hemorrhage (p = 0.04; aOR, 0.16; 95% CI, 0.01-0.98).

The FPE with an SR alone improved the neurological prognosis in a Japanese patient group.