Efficacy and safety of direct aspiration versus stent-retriever for recanalization in acute cerebral infarction A PRISMA-compliant systematic review and meta-analysis

Background and purpose: Whether the direct aspiration approach of thrombectomy for recanalization in patients with acute ischemic stroke has a similar efficacy and safety compared to the stent-retriever remains uncertain. Methods: We conducted a meta-analysis of 9 studies obtained through PubMed and Embase database searches to determine whether successful recanalization rate, good functional outcome at 3 months (modified Rankin score, mRS <= 2), procedure time from groin puncture to maximal revascularization and procedure-related adverse events differed between patients who underwent the direct aspiration and those receiving stent-retriever for recanalization in acute cerebral infarction. Results: There was no significant difference between the direct aspiration group and the stent-retriever group in rate of successful recanalization (summary odds ratio [OR], 0.86 [95% confidence interval (CI), 0.45- 1.52]; P=.60), but a better functional outcomes in the direct aspiration group at 3 months defined as a mRS score of 0 to 2 (OR, 0.77; 95% CI, 0.66-0.97; P=.03). Furthermore, the direct aspiration patients compared with the stent-retriever patients had a tendency of shorter procedural time (Mean difference [MD], -8.77 [95% CI, from-18.90 to 1.37]; P=.09). Finally, there were less adverse events especially in symptomatic intracerebral hemorrhage (sICH) (OR, 0.56; 95% CI, 0.33-0.98; P=.04) and embolization to a new territory (ENT) (OR, 0.49; 95% CI, 0.28-0.84; P=. 01) in the direct aspiration group when compared with the stent-retriever group, although no difference between them in the rate of any ICH (OR, 0.81; 95% CI, 0.41-1.60; P=.54). Conclusions: The results support that the direct aspiration technique for those acute ischemic stroke patients may have better functional outcomes, less procedure related-adverse events and a tendency of faster revascularization time as compared to the stent-retriever thrombectomy, with a similar successful recanalization rate. However, major limitations of current evidence (mainly from retrospective and observational studies and a small number of patients population) indicate a need for adequately powered, multicenter randomized controlled trials (RCT) to answer this question.