The technique of unilateral double lobar lung transplantation in a canine model

Objective: Bilateral living-donor lobar lung transplantation has become an accepted alternative to cadaveric lung transplantation. Because only one lobe is implanted in each chest cavity, this procedure seems to be best suited for children and small adults. The purpose of this study was to develop a technique of unilateral double lobar lung transplantation that can be applied to large adult patients. Methods: Unilateral double lobar lung transplantation was performed in 6 weight-matched pairs of dogs. In donor animals the right middle, lower, and cardiac lobes were separated as a right graft, and the left lower lobe was separated as a left graft. In recipient animals these 2 grafts were implanted in the right hemithorax after right pneumonectomy. The left graft was implanted as a right upper lobe, having been rotated 180° along the vertical axis and then 180° along the horizontal axis. The right graft was implanted in the natural anatomic position. Function of the transplanted grafts was assessed for 3 hours after ligation of the left main pulmonary artery while the animals were ventilated with 100% oxygen. Results: Morphologic adaptation of the 2 grafts in the right hemithorax was found to be excellent. All 6 animals survived the assessment period with excellent pulmonary function. At the end of the 3-hour assessment period, the arterial oxygen tension was 519 ± 31 mm Hg, and the mean pulmonary artery pressure was 30.5 ± 1.7 mm Hg. Conclusions: Unilateral double lobar lung transplantation was technically possible and associated with satisfactory early pulmonary function in a canine experimental model.