Cardiovascular Journal of Africa: Vol 32 No 6 (NOVEMBER/DECEMBER 2021)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 6, November/December 2021 344 AFRICA Lung transplantation was decided upon as a course of treatment after multidisciplinary consultation. The procedure was performed after four weeks of mechanical ventilation and two weeks after initiating veno-venous ECMO support. In the operation room, pre-operative transoesophageal echocardiography (TEE) showed mild dilation of the right ventricle (RV) with a fractional area change (FAC) of 30% and moderate tricuspid regurgitation (TR) with a peak pressure gradient (PPG) of 64 mmHg (Fig. 2A). No other structural or functional abnormalities were observed. Implantation of an allograft was uneventfully completed under cardiopulmonary bypass support. After reperfusion of the allograft, the TEE showed laminar flow across the pulmonary vascular anastomoses and mild TR with a PPG of 30.5 mmHg. Additionally, the TEE revealed right heart dilation with a RV FAC of approximately 20% (Fig. 2B). Persistent RV failure required the initiation of veno-arterial ECMO (VA-ECMO) with cannulation of the left femoral artery and retention of the right femoral vein cannula. Subsequently, the TEE confirmed normal systolic cardiac function on VA-ECMO support. The patient was transferred to an isolated room in the intensive care unit (ICU) and received the standard post-transplantation therapeutic protocol. On postoperative day two, the oxyhaemoglobin saturation declined markedly while performing an ECMO weaning trial by reducing the ECMO flow from4 to 2 l/min. X-rays revealed patchy shadows of exudation. On postoperative day three, hypoxaemia was confirmed by blood gas analysis. A fibre bronchoscope revealed a substantial amount of thin, watery secretion in the airway. Bedside TEE was performed under transient sedation, and patency of the delicate vascular anastomoses and normal cardiac systolic function was confirmed. Furthermore, the TEE showed moderate TR with a PPG of 52 mmHg (Fig. 2C), which did not markedly change with a change in ECMO flow. An approximate 10-mm thickening of the RV wall was observed (Fig. 2D). The combination of clinical signs indicated that primary graft dysfunction, mainly caused by allograft rejection, should Fig. 2. Imaging of transoesophageal echocardiography (TEE). A. TEE showing tricuspid peak pressure gradient of 64 mmHg before surgery. B. TEE showing dilation of the right heart. C. TEE showing tricuspid peak pressure gradient of 52 mmHg on postoperative day three. D. TEE showing thickening of the right ventricular wall. LA: left atrium, LV: left ventricle, RA: right atrium, RV: right ventricle. A C B D