New technique of vascularization of the trachea and bronchus for lung transplantation

Ischemic necrosis is implicated as a major cause of dehiscence and stenosis of the airway anastomosis in double and single lung transplants. A new surgical technique to maintain systemic arterial blood flow to the transplanted airways by preserving the donor tracheobronchial arterial circulation was investigated. In a primate model, the tracheobronchial arterial circulation to the transplanted airways was maintained by inclusion of an aortic segment with its bronchial arteries and tracheal collaterals in continuity with the lung bloc. The aortic segment, from just proximal to the left subclavian artery to the level of the pulmonary hilum, was vascularized by anastomosis of the subclavian artery to the recipient left subclavian artery or ascending aorta. Double lung transplantation was performed in three baboons; two survived 48 hours, and one was killed at 30 days. One baboon with a left single lung transplant was killed at 30 days, and one baboon with a right single lung transplant survived 22 days. Angiograms obtained 14 days after transplantation showed patent subclavian anastomoses and aortic segments. Postmortem examination revealed patent subclavian anastomoses without thrombi in the aortic segments. There was no airway necrosis, dehiscence, or stenosis. Tracheal and bronchial anastomoses of surviving animals were healed. Histologic examination revealed typical respiratory tissues without ischemia or necrosis. Radiographic examination of aortic segments injected with lead oxide showed patent bronchial arteries extending along the donor trachea and bronchi and to the anastomotic sites. These experimental studies demonstrate that this technique maintains the donor tracheobronchial arterial circulation and may improve tracheal and bronchial anastomotic healing.