The protekduo as double lumen arterial return cannula in extracorporeal membrane oxygenation

Objective: We present 3 cases of acute respiratory distress syndrome (ARDS) secondary to COVID-19 pneumonia who required veno-venous extracorporeal membrane oxygenation (V-V ECMO) using the ProtekDuo right ventricular assist device (RVAD). Method: The first patient was transferred to our institution for advanced management, having a ProtekDuo with an oxygenator in veno - pulmonary- arterial(V-pA) position. The patient remained hypoxemic and therefore we modified the configuration using a 25 Fr femoral multistage drainage cannula that was inserted for venous drainage only. The arterial return tubing was spliced and using a Y-connector, arterialized blood was returned through both lumina of the ProtekDuo. Based on this experience we changed 2 more patients who were on ProtekDuo to this new configuration. Results: This modified novel configuration resulted in significantly increased oxygenation (SpO2 from 78% to 100%) and flow (from 4.2 LPM to 7.0 LPM) in patient #1. The patient recovered and was successfully weaned and separated from ProtekDuo after 44 days, of which 29 days were on the modified configuration, without any device-related complications. Patient #2 has been successfully weaned off ECMO and presently is undergoing physiotherapy and rehabilitation. Patient #3 has recently been placed on V-pA ECMO and is presently being managed. Discussion: This modified novel configuration is presently under investigation and exact mechanisms need to be described. Direct return of arterialized blood into the pulmonary artery without mixing in the right atrium and reduction of shunt fraction may play major roles. Conclusion: This novel configuration appears beneficial and safe without right atrial strain.