Abstract 17180: Association of Arterial Return Cannula Size with Survival in Adults Undergoing Venoarterial Extracorporeal Membrane Oxygenation: an ELSO Registry Analysis

Introduction: Peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used to support critically ill adults with cardiogenic shock (CS), but the impact of arterial cannula size on survival remains poorly understood. Hypothesis: A smaller arterial return cannula will be associated with similar survival. Methods: We queried the ELSO registry for adults undergoing VA-ECMO from 2017-2022 and stratified them into small (<16 Fr) versus large (≥16Fr) arterial cannula size. We restricted the cohort to patients with body surface area (BSA) 1.8-2.2 m 2 and excluded patients with a concomitant left ventricular venting device, central cannulation, and multiple ECMO runs. The primary outcome was 30-day in-hospital mortality and secondary outcomes included 24-hour lactate clearance and rates of on-support acute renal and liver injury. Results: Among 2963 adults receiving peripheral VA-ECMO without a concomitant left ventricular venting device, 491 (16.6%) patients had a small arterial cannula and 2,472 (83.4%) had a larger cannula. Patients with a larger cannula were more often male, had marginally higher BSA, a higher incidence of pre-ECMO organ failures, and more often had a distal perfusion cannula (Figure, panel A). There was no difference in 30-day mortality between patients with small (40.3%) versus large (42.9%) arterial cannula, p= 0.295 (Figure, panel B), which persisted after multivariable modeling: adjusted hazard ratio 0.97 (95% CI: 0.79-1.19, p= 0.78). Lactate clearance at 24 hours of ECMO support (Figure, panel C) and the rates of acute renal injury (37% vs 41%, p = 0.024) and hyperbilirubinemia (4.3% vs 4.3%, p = 0.96) were similar between the two arterial cannula size cohorts. Conclusion: For adult patients undergoing peripheral VA-ECMO support, the use of a smaller (<16F) versus larger (≥16F) arterial return cannula was associated with similar rates of in-hospital mortality and metrics of end-organ perfusion.