Efficacy of Distal Perfusion Cannulae in Preventing Limb Ischemia During Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis.

To date, no consensus exists regarding indication, technique, or efficacy of distal perfusion cannulae (DPC) in preventing limb ischemia among patients receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO). We aim to examine the available literature and report association between DPC and risk of limb ischemia. PubMed/Medline, Scopus, Cochrane Central Register of Controlled Trials, Google Scholar, and bibliographies of included studies were searched from database inception until August 2016. Original studies describing the DPC placement technique and incidence of limb ischemia following DPC placement among VA-ECMO patients were included for systematic review. Studies with a comparison group of patients without DPC were included for meta-analysis. Two authors independently screened title/abstracts, reviewed full texts, and extracted data from the eligible studies. Meta-analysis was performed using the Mantel-Haenszel method under a random-effects model. Statistical heterogeneity was examined with the I2 statistic (RevMan Version 5.3). Of 542 title/abstracts screened, 62 full text articles were selected for review, yielding 22 retrospective observational studies, for a total of 779 patients with 132 limb ischemia events. There was significant variation in DPC indication, cannula type, and placement technique among the studies. Compared to no DPC, the presence of a DPC was associated with at least a 15.7% absolute reduction in the incidence of limb ischemia (9.74 vs. 25.42%; risk ratio 0.41; 95% confidence interval 0.26-0.65, P < 0.01; heterogeneity statistic I2 = 28%). There was no statistically significant difference in mortality in the pooled dataset comparing DPC versus no DPC. In adults treated with VA-ECMO, DPC placement was associated with a lower incidence of limb ischemia. Currently no consensus guidelines exist regarding indication for DPC placement. Given the association described in this analysis, future prospective trials are warranted to establish a causal relationship and optimal technique for the use of DPC in patients treated with VA-ECMO.