Modification of the arterial anastomotic technique improves survival in porcine single lung transplant model.

BACKGROUND

Lung transplantation is a valuable therapeutic option for selected patients with end-stage pulmonary disease. However, this treatment is complicated by ischaemia-reperfusion injury (IRI) of the lung in 10-20% of the recipients. We developed an unilateral porcine lung transplant model to study IRI and describe our experience with two different arterial anastomotic techniques.

MATERIAL & METHODS: Twenty four domestic pigs [n = 6 x (donor + recipient)/group] were used in this study. Donor lungs were harvested using an antegrade flush with cold Perfadex and stored in the same solution for +/- 8 hours. Recipient animals underwent a left thoracotomy. After native pneumonectomy, the left donor lung was transplanted in the following order: 1. left atrial cuff; 2. bronchus; 3 pulmonary artery. 2 The outcome in recipients from historical groups differing in anastomotic technique was compared. An end-to-end anastomosis on the left pulmonary artery was performed in group I versus a patch anastomosis on the main pulmonary artery in group II. One hour after reperfusion, the right pulmonary artery and main bronchus were ligated forcing the recipient to survive on the transplanted lung only. The animals were further observed for 6 hours.

RESULTS

Survival 6 hours after exclusion of the right lung was 33% (2/6) in group I versus 83% (5/6) in group II. Animals in group I died of right heart failure manifested by acute dilation of the right ventricle following ligation of the hilum of the right lung.

CONCLUSION

Single lung transplantation with exclusion of the contralateral native lung is a critical model. Arterial end-to-end anastomosis resulted in an increased right ventricular afterload. The use of a patch technique improved the compliance of the arterial anastomosis and decreased early mortality. This transplant model is currently used in our laboratory to assess new methods for pulmonary preservation.