Impact of Multistage Cannula on Recirculation in Various Venovenous Extracorporeal Membrane Oxygenation Cannulation Strategies.

We aimed to compare recirculation of venovenous extracorporeal membrane oxygenation (V-V ECMO) administered with various cannula placements for femoro-femoral (F-F) and femoro-jugular (F-J) configurations in patients with respiratory failure. This single-center retrospective study included 58 consecutive patients who underwent V-V ECMO between January 2021 and December 2023. Ultrasonic dilution technology was used to quantify the flow of recirculation. The drain cannula placements were categorized into three positions: right atrium and superior and inferior venae cavae. The primary outcome was the difference in recirculation according to the configuration of the V-V ECMO and cannula tip placement. The secondary outcomes were the correlations between recirculation and distance between cannula tips and recirculation difference after cannula adjustment. The recirculation fractions for all types of F-J (27.18%) and F-F (29.33%) configurations were not significantly different. No significant correlation ( r = 0.14) was observed between recirculation and the distance between the drain and return cannula tips in chest radiography. The configuration and placement of the drain cannula may have limited effects on recirculation when using a multistage continuous cannula while applying V-V ECMO.