Background: Right heart failure remains the leading early cause of mortality after heart transplantation, especially with antecedent pulmonary hypertension. Paradoxically, the discarded recipient right heart, acclimated to pulmonary hypertension, is often stronger than its nonconditioned donor replacement. Heterotopic ("piggyback") transplantation is plagued by problems related to the retained, dilated, hypocontractile left ventricle (lung compression, systemic emboli, arrhythmias). Were it possible to retain the recipient's right heart, excising only the left ventricle, this could have important advantages, especially in severe pulmonary hypertension. This report describes such a technique.
Methods and results: In four transplantation experiments (dogs), right ventricular-sparing transplantation proved technically feasible and hemodynamically successful. Bleeding after excision of the left ventricle was easily controlled. Back-bleeding from the native aortic valve (now open into the pericardial space) was not problematic. All atrial, aortic, and pulmonary arterial connections proved feasible. The preserved recipient right heart of all animals remained in stable sinus rhythm. All recipients were easily weaned from cardiopulmonary bypass, maintaining mean arterial pressures 60 to 110 mm Hg.
Conclusions: This investigation develops a technique for donor right ventricle sparing in cardiac transplantation, demonstrating technical and hemodynamic feasibility. This method holds promise for the unsolved clinical problem of right heart failure after orthotopic heart transplantation with antecedent pulmonary hypertension.