VENO-ARTERIAL EXTRACORPOREAL MEMBRANE OXYGENATION SUPPORT AS A BRIDGE TO HEART-LUNG TRANSPLANTATION IN A PATIENT AFFECTED BY EINSENMENGER'S SYNDROME COMPLICATED BY PNEUMONIA AND SEVERE RIGHT VENTRICULAR FAILURE

Abstract

Objective

We report a case of a 58-year-old male suffering from primary pulmonary arterial hypertension (PH), Eisenmenger's syndrome (ES) and ischemic heart disease who has already undergone multiple revascularizations and is a candidate for en bloc heart-lung transplantation.

Design and method

The patient acceded to our center with pneumonia and consequent worsening of respiratory symptoms and asthenia. The echocardiogram demonstrated a severely dilated and hypokinetic right ventricle with a systolic-diastolic D-shape and massive tricuspid regurgitation besides a dilated and fixed inferior vena cava. Considering the clinical worsening with advanced cardiorespiratory failure and the lability of hemodynamic compensation, hospitalization in cardiac intensive care was proposed. Upon admission, the patient presented a picture of predominantly right-sided SCAI D cardiogenic shock in type I PH and severe hypoxia.

Initially, the hemodynamic instability was successfully medically managed with epinephrine intravenous (IV) infusion, a combination of multiple pulmonary vasodilators (Milrinone EV, Epoprostenol EV, Treprostinil continuous SC infusion and iNO) and Non-Invasive Ventilation (NIV). The patient was then included in the emergency transplantation list.

Unfortunately, pneumonia severely worsened the pulmonary oxygenation with subsequent right ventricle de-compensation, increasing the right-to-left shunt and precipitating the cardiorespiratory equilibrium.

We discussed the possibility of supporting the patient with veno-venous (VV) ECMO, but the RV failure was too severe (TAPSE 11 mm, FAC 20%, PAPs 92 mmHg, CVP 18 mmHg) and unresponsive to maximal medical therapy to allow the venous-venous support adequate effectiveness. Therefore, we decided to assist the patient with an awake femoral-femoral veno-arterial (VA) ECMO bridge-to-transplantation.

As expected, it was not a simple mechanical circulatory support (MCS) management: the good LV function and the severe RV dilation made it impossible to obtain full drainage of the heart, which continued to eject de-oxygenated blood in ascending aorta. Veno-arterial-venous (VAV) ECMO was considered, but the incomplete RV drainage made it impossible to avoid liver stasis and a VAV configuration was considered inapplicable to manage the Harlequin Syndrome which occurred. Therefore, to improve the oxygenation in the “upper circulation” and, at the same time, to maintain the patient awake and able to prosecute physiotherapy, we assisted the patient with High-Flow Nasal Cannula (HFNC 50 L/min FiO2 100%) connected to an inhaled Nitric Oxide circuit (iNO 20ppm).

In this way, we managed to assist the patient for 10 days, up to organs arrival, and the the patient was successfully transplanted.

Results and conclusions

This case highlights the complexity and still the feasibility of VA ECMO support, complicated by Harlequin Syndrome, as a bridge to heart-lung transplantation in acutely decompensated patients with ES, in which the conditions of the right heart could not tolerate the VV ECMO solution.