LAUSR

INTRODUCTION Acute limb ischemia (ALI) and cannulation site bleeding are frequent complications of veno-arterial (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 catheters (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 (e.g., 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 (OR 0.25; 95% CI 0.08-0.77, p=.02) was associated with decreased risk of ALI, while cannulation in the operating room (OR 2.65; 95% CI 1.09-6.45, p=.03) and cut-down 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); however, DPC was not associated with either ALI (p=0.47) or bleeding (p=0.06). 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 following peripheral VA-ECMO cannulation. While 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.