Risk factors for lower extremity vascular complications in adult patients on veno-arterial extracorporeal membrane oxygenation

Objective: Utilization of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has increased significantly over the last decade. Prior studies have reported worse mortality for patients with vascular complications on VA-ECMO; however, these were limited by small sample size. The purpose of this study is to investigate predictive risk factors for vascular complications in VA-ECMO patients and their potential impact on mortality. Methods: Patients who underwent peripheral VA-ECMO from January 2011 to December 2021 were identified. Primary outcomes were lower extremity vascular complications and in-hospital mortality. Multivariate stepwise logistic regression models were used to identify predictors of vascular complications and in-hospital mortality. Results: A total of 605 VA-ECMO patients (25% female) were identified. The mean age was 56.3 ± 13 years, and 56 (10.4%) were black. In-hospital mortality was 63.8% (n = 386), and VA-ECMO ipsilateral vascular complications occurred in 72 patients (11.9%). Vascular surgical interventions (thromboembolectomy, fasciotomies, amputation, and surgical management of cannula bleeding) were required in 30 patients (41.7%). Same-side arterial and venous cannulas, cannula size, and absence of distal perfusion cannula did not increase risk of vascular complication. Multivariate analysis identified age (odds ratio, 0.948; 95% confidence interval, 0.909-0.988; P = .0116) and pre-existing peripheral arterial disease (odds ratio, 3.489; 95% confidence inteval, 1.146-10.624; P = .0278) as independent predictors of need for vascular surgery interventions. The mortality rate of patients who developed vascular complications was not significantly different compared with the mortality rate of those who did not develop vascular complications (61% vs 64%; P = .92). Conclusions: This study represents one of the largest series to date of lower extremity vascular outcomes in patients undergoing VA-ECMO. Our results confirm the high mortality rate associated with VA-ECMO; however, vascular complications did not represent a risk factor for mortality as previously reported. Same-sided VA-ECMO cannulas, cannula size, and the presence or absence of distal perfusion cannula did not predict vascular complications. Increasing age and presence of peripheral arterial disease are independent predictors of need for vascular surgery intervention in patients on VA-ECMO.