Oxygenated right ventricular assist device as part of veno-venopulmonary extracorporeal membrane oxygenation to support the right ventricle and pulmonary vasculature

Abstract

COVID-19 infection can lead to severe acute respiratory distress syndrome (ARDS), right ventricular (RV) failure and pulmonary hypertension. Venovenous extracorporeal membrane oxygenation (V-V ECMO) has been used for patients with refractory hypoxemia. More recently dual-lumen right atrium to pulmonary artery oxygenated right ventricular assist devices (Oxy-RVAD) have been utilized in the severe medical refractory COVID ARDS setting. Historically, animal data has demonstrated that high continuous non-pulsatile RVAD flows, leading to unregulated and unprotected circulation through the pulmonary vessels is associated with an increased risk of pulmonary hemorrhage and increased amount of extravascular lung water. These risks are heightened in the setting of ARDS with fragile capillaries, left ventricular (LV) diastolic failure, COVID cardiomyopathy, and anticoagulation. Concurrently, due to infection, tachycardia, and refractory hypoxemia, high V-V ECMO flows to match high cardiac output are often necessary to maintain systemic oxygenation. Increase in cardiac output without a concurrent increase in VV ECMO flow will result in a higher fraction of deoxygenated blood returning to the right heart and therefore resulting in hypoxemia. Several groups have suggested using a RVAD only strategy in COVID ARDS; however, this exposes the patients to the risk of pulmonary hemorrhage. We present one of the first known cases using an RV mechanical support, partial flow pulmonary circulation, oxygenated Veno-venopulmonary (V-VP) strategy resulting in RV recovery, total renal recovery, awake rehabilitation, and recovery.

Keywords: Acute Right Ventricular failure; Dual Lumen Cannula; Echocardiography; Mechanical circulatory support; Protek Duo; RA-PA cannula; Right ventricular assist device.

Fig. 1

Diagram demonstrating oxygenation of both limbs of the dual-lumen Protek Duo cannula. Oxygenating the proximal limb creates a configuration similar to conventional venovenous ECMO while oxygenating the distal limb creates an oxygenated right ventricular assist device. This configuration is V-VP ECMO with split flow to the pulmonary artery and the right atrium

Fig. 2

Dual-lumen single cannula as dual oxygenated outflow to the RA and RV. The distance between the RA limb and the femoral inflow cannula is 7 cm to minimize recirculation

Fig. 3

Dual oxygenated V-VP ECMO with flow sensor and clamp applied. The flow sensor is positioned on the distal limb to monitor the PA blood flow closely. The clamp is applied on the proximal low pressure RA limb to calibrate the flow appropriately to avoid pulmonary artery overcirculation. There is a 3/8’’ Y tubing connector splitting flows