NORMAL BRONCHIAL HEALING WITHOUT BRONCHIAL WRAPPING IN CANINE LUNG TRANSPLANTATION

The deleterious effect of steroids on bronchial healing in lung transplantation has led to the development of techniques to protect the anastomosis and to the exclusion of steroid-dependent patients from transplantation. The effect of steroids on bronchial healing was tested in a canine single-lung allotransplantation model. Twenty size-matched mongrel dogs (20 to 30 kg) underwent left lung transplantation without anastomotic wrap or direct revascularization. Postoperatively, all received daily doses of cyclosporine (15 mg/kg) and azathioprine (1 mg/kg) and were subdivided into three steroid dosage groups. Group A (n = 10) animals received 1.5 mg/kg of prednisone per day whereas groups B (n = 5) and C (n = 5) received 5.0 mg/kg of prednisone per day for 28 postoperative days. In addition, group C received prednisone (5.0 mg . kg-1 . day-1) for 1 month preoperatively. In group A, 8 of 10 dogs survived 28 days without evidence of respiratory compromise, with anastomotic bursting pressure greater than 510 mm Hg. In group B, all 5 dogs survived to 28 days without evidence of respiratory compromise and with intact bronchial anastomoses (bursting pressures greater than 510 mm Hg). In group C, 3 of 5 animals survived to 28 days with intact anastomoses. Histological examination demonstrated normal bronchial healing in all anastomoses. These data suggest that preoperative steroid dependence should not be a contraindication to lung transplantation and that bronchial anastomotic wrapping with vascular tissue may not be essential.