Acute and chronic effects of bilateral lung transplantation without cardiopulmonary bypass on the first transplanted lung

Background. Bilateral lung transplantation (BLT) without cardiopulmonary bypass (CPB) may exacerbate reperfusion injury to the initially engrafted lung because of increases in pulmonary flow during implantation of the second graft. Methods. In a retrospective review of 23 BLT patients, we hypothesized that BLT without CPB injures the first transplanted lung measured by acute and late graft dysfunction compared to the second transplanted lung. Of the 23 BLT, 19 underwent transplantation without CPB while 4 patients were placed on CPB secondary to hemodynamic instability. Results. Acute graft function was assessed by radiographic scoring of lung quadrants (blinded radiologist; 0 = no infiltrate; 1 = infiltrate; maximum = 2 per lung) and by arterial/alveolar oxygen tension ratios (PaO2/FiO2) ratios. Late graft function was evaluated by quantitative perfusion scan. Lung perfusion was graded as abnormal if less than 50% on the right or less than 45% on the left (Fisher’s exact). Radiographic scores were not different between first and second implanted lungs at 1 and 24 hours, PaO2/FiO2 ratios at 1 and 24 hours were 273 ± 26 and 312 ± 23, respectively, and perfusion scans at 3 and 12 months revealed normal differential blood flow. Conclusions. These findings suggest no acute or chronic differences occur between the first or second transplanted lung completed without CPB.