Novel technique for isolated accessory right heart transplantation for congenital heart disease
John Elefteriades1, Costantinos Lovoulos, Randolph Edwards
1Section of Cardiothoracic Surgery, Yale University School of Medicine, New Haven, CT 06510, USA. john.elefteriades@yale.edu
Background:
Our prior laboratory work has permitted adding a whole donor heart to a preserved recipient right heart, producing a heart-and-a-half preparation able to cope with pulmonary hypertension in the recipient. The experiments in the present study explore the feasibility of the converse operation: adding an isolated donor right heart to an entire preserved heart.
Methods:
Eight adult mongrel dogs (4 donors and 4 recipients) were used in 4 transplant operations performed through a right thoracotomy without cardiopulmonary bypass (using side-biting control of recipient vessels). The donor heart underwent resection of the left atrium and left ventricle, leaving an isolated donor right heart. Blood supply to the donor right ventricle was preserved from the donor ascending aorta. Through a right thoracotomy, the donor right heart was transplanted in parallel to the native right heart of the recipient by using the following anastomoses: (1) donor superior vena cava to recipient superior vena cava (end-to-side anastomosis); (2) donor pulmonary artery to recipient pulmonary artery (end-to-side anastomosis); (3) donor ascending aorta to recipient aorta (through a great vessel [end-to-end anastomosis] to provide arterial inflow to donor coronary arteries). Animals were euthanized within 1 hour after completion of transplantation.
Results:
Isolation of the right ventricle by excision of the left chambers was technically feasible. Transplantation without cardiopulmonary bypass was feasible in all cases. The isolated right heart beat well after transplantation in all animals, demonstrating sinus rhythm. Three of 4 animals were able to sustain good hemodynamics on support with epinephrine. Bleeding from the septum or aortic valve of the donor (now open to the pericardial space) was not problematic. Mean arterial pressure was 85 mm Hg (mean) at a right atrial pressure of 6 mm Hg (mean). In 2 animals the recipient superior vena cava was ligated to obligate upper body flow to pass through the accessory ventricle; hemodynamics were preserved under these circumstances.
Conclusion:
Transplantation of an isolated right heart is feasible. Such a technique has potential as a novel therapeutic alternative for obstructive or hypoplastic lesions of the right heart in human children.
