Controlled flow diversion in hybrid venoarterial-venous extracorporeal membrane oxygenation.

OBJECTIVES: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.