Controlled flow diversion in hybrid venoarterial-venous extracorporeal membrane oxygenation

Patients on venoarterial or venovenous extracorporeal membrane oxygenation (ECMO) support may require venoarterial-venous (VAV-ECMO) configuration during follow-up. We report 12 cases of VAV-ECMO with significant outflow steal.

Between October 2014 and November 2016, a total of 97 patients (56.6 ± 12.0 years; 59 men/38 women; body surface area 1.84 ± 0.36 m2) were supported with venoarterial ECMO (n = 85) or venovenous ECMO (n = 12). Among the 97 patients, 12 patients (age 61.5 ± 3.5 years; 8 men/4 women; body surface area 1.8 ± 0.8 m2) required hybrid use of VAV-ECMO. Control and monitoring of flow ratios in supplying cannulae using flow sensors were performed, and occluder devices were used according to patient requirements to achieve optimum haemodynamics and oxygenation.

Among the 85 venoarterial ECMO-supported patients, Harlequin syndrome was detected in 9 cases (10.6%) who required switching to VAV-ECMO. Among the 12 patients, 3 (25%) patients required VAV-ECMO while on venovenous ECMO support as a result of initial respiratory failure subsequently developed cardiac decompensation. Mean duration of VAV-ECMO support was 6.4 ± 1.8 days. Overall, on VAV-ECMO support, 70.0 ± 4.6% of blood flow was detected within the supplying right internal jugular vein cannula as a result of lower afterload in venous system. We partially occluded the internal jugular vein cannula and directed flow to the common femoral artery. After adjustment, 34.3 ± 7.4% flow was directed to internal jugular vein and 65.6 ± 7.4% to common femoral artery.

Non-invasive monitoring of flow rates within the supplying cannulae of VAV-ECMO and the use of partial occlusion for venous-supplying cannula enable individualized patient management and effective weaning from VAV-ECMO.