Limb ischemia and bleeding in patients requiring venoarterial extracorporeal membrane oxygenation

Objective: Acute limb ischemia (ALI) and cannulation site bleeding are frequent complications of venoarterial (VA) extracorporeal membrane oxygenation (ECMO) and are associated with worse outcomes. The goals of this study were to assess our rates of ECMO-related ALI and bleeding and to evaluate the efficacy of strategies to prevent them, such as distal perfusion cannula (DPC) and ultrasound-guided cannulation. Methods: This is a single-center retrospective cohort study of adult patients placed on peripheral VA-ECMO at a tertiary medical center between 2014 and 2018. ALI was defined as new ischemia of the extremity ipsilateral to arterial cannulation. Significant cannulation site bleeding was defined as excessive bleeding requiring intervention (eg, transfusion or reoperation). Univariate analyses were used to identify factors associated with ALI, bleeding, and in-hospital mortality. Results: During the study period, 105 patients were placed on peripheral VA-ECMO (61.3% female; mean age, 54.9 ± 14.8 years). Nearly half (46.6%) had ECMO implantation in an extracorporeal cardiopulmonary resuscitation setting and 37 (44.0%) had a DPC. Average duration of support was 5.6 ± 5.0 days. Overall in-hospital mortality and death on ECMO support were 65.1% and 50%, respectively. ALI occurred in 21 (20%) and cannulation-related bleeding occurred in 24 (22.9%) patients who were treated with a total of 27 procedures, including thromboembolectomy (22.2%), vascular repair (18.5%), and fasciotomy (25.9%). On univariate analysis, cannulation in the operating room (odds ratio [OR], 0.25; 95% confidence interval [CI], 0.08-0.77; P = .02) was associated with decreased risk of ALI, whereas cannulation in the operating room (OR, 2.65; 95% CI, 1.09-6.45; P = .03) and cutdown approach (OR, 4.96; 95% CI, 2.32-10.61; P < .0001) were associated with increased risk of bleeding. Ultrasound-guided placement was associated with decreased risk of bleeding (OR, 0.81; 95% CI, 0.04-0.84; P = .03). DPC was not associated with either ALI (P = .47) or bleeding (P = .06). ALI (OR, 2.68; 95% CI 1.03-6.98; P = .04), age (OR, 1.94; 95% CI, 1.03-3.69; P = .04), and worse baseline heart failure (OR, 2.01; 95% CI, 1.02-3.97; P = .04) were associated with greater risk of in-hospital mortality. Ultrasound-guided cannulation (OR, 0.41; 95% CI, 0.20-0.87; P = .02) was associated with decreased risk of in-hospital mortality. Conclusions: ALI and significant bleeding are common occurrences after peripheral VA-ECMO cannulation. Whereas DPC placement did not significantly decrease risk of ALI, ultrasound-guided cannulation decreased the risk of bleeding. Cannulation in the operating room is associated with decreased risk of ALI at the expense of increased risk of bleeding. ALI, older age (≥65 years), and worse heart failure increased risk of in-hospital mortality.