Right-sided cardiac transplantation: importance of functional valves

An original surgical procedure had been developed entailing the implantation of a right-sided heterotrophic cardiac graft in 14 dogs. The benchwork preparation included creation of both atrial and ventricular septal defects which allowed transplantation with the avoidance of extracorporeal circulation and the utilization of all transplanted myocardium and parts. The structure and function of this graft were sequentially evaluated using rapid cine-computed tomograms which permitted assessment of forward graft flow, ventricular wall contraction, and diastolic thickness for both the native and grafted hearts. These parameters were followed during the early (E) (less than 3 days), intermediate (I) (4-21 days), and late (L) (greater than 21 days) postoperative periods. Forward flow (E: 3.0, I: 1.5, L: 2.6) through the transplant was maintained by the competence of the implanted valves despite a progressive decrease in the contraction (E: 3.0, I: 1.3, L: 1.0) and associated decrease in the wall thickness (E: 3.0, I: 2.6, L: 2.4). These findings were consistent with severe cardiac graft rejection without immunosuppression. In summary, long-term structural and functional forward flow of this configurated right-sided transplantation had been maintained by the competent valves on both sides of the graft despite severe rejection without immunosuppression as documented by rapid cine-computed tomograms.