The heterotopic right heart assist transplantation

Heterotopic heart transplantation has been utilized experimentally and clinically to assist the recipient heart in maintaining either the systemic circulation alone or both the systemic and pulmonary circulations. We describe a model in which the heterotopic heart transplantation is utilized to supply the pulmonary circulation while the recipient heart acts as the systemic ventricle. This procedure might be used for selected patients with complex congenital heart disease. The method we have used in five dogs (16.5 to 23.5 kg) consists of preparation of the donor heart by excision after cardioplegic arrest, ligation of the venae cavae, anastomosis of the donor pulmonary artery (PA) to the donor left atrial appendage, and insertion of a left ventricular (LV) apical Dacron graft connected to a valved aortic allograft. Implantation in the recipient consists of anastomosis of the donor left atrium to the recipient right atrium, anastomosis of the LV apical conduit to the recipient main PA, and anastomosis of the donor aorta to the recipient ascending aorta to supply oxygenated blood to the donor coronary circulation. The recipient right ventricle (RV) in the experimental model is inactivated by inducing tricuspid regurgitation and by ligating the proximal PA. Early survival (3 hours) with stable hemodynamic measurements was obtained in all dogs, with the recipient RV excluded from the circulation and with the donor LV pumping the total systemic venous return to the PA. Pulmonary blood flow was maintained even when the ventricular pressure was raised to systemic levels by narrowing the conduit.(ABSTRACT TRUNCATED AT 250 WORDS)