A canine experimental study to assess the potential of unilateral double lobar lung transplantation

Objective: We recently reported a technique of unilateral double lobar lung transplantation (UDLLT) in a canine model that was associated with satisfactory early pulmonary function. The purpose of the present experimental study was to assess the quality of bronchial healing, complication rates, survival rates and long-term pulmonary function of this new transplantation technique. Methods: Unilateral double lobar lung transplantation was performed in 14 weight-matched pairs of dogs. In recipient animals, two grafts obtained from donor animals were implanted in the right hemithorax after right pneumonectomy. One graft (left graft) was implanted as a right upper lobe in an upside-down position and the other (right graft) was implanted in the natural anatomic position. The immunosuppressed recipients were observed for 3 weeks. Transplanted graft function was assessed under left main pulmonary artery occlusion at 1 and 3 weeks after transplantation. Results: All animals survived the operation. Pulmonary artery kinking (3/14, 21%) and pulmonary venous thrombus (4/14, 29%) were exclusively observed in the graft implanted in the upside-down position. These complications decreased as the number of transplantations increased. Two of the first seven (29%) and five of the last seven recipient dogs (71%) survived for 3 weeks with excellent pulmonary function and good bronchial healing. Conclusions: This procedure was associated with a high complication incidence in the non-anatomically positioned graft. However, a precise surgical technique could decrease these complications. This technically demanding procedure provided excellent pulmonary function and good bronchial healing.