Should double lung transplant be performed with or without cardiopulmonary bypass?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was whether double lung transplantation should be performed with or without cardiopulmonary bypass (CPB) in order to improve postoperative clinical outcomes. Altogether 386 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All 14 papers assessed a range of postoperative outcomes and broadly speaking, six papers found significantly worse outcomes with CPB use, six found no difference and two found a mixture of both depending on the specific outcomes assessed. Dalibon et al. [J Cardiothorac Vasc Anesth 2006;20:668-672] found that mortality was significantly worse in the CPB group at 48 h, one month and one year [P = 0.001, odds ratio (OR) = 246.1; P = 0.083, OR = 2.6; P = 0.001, OR = 5.3, respectively]. Other papers revealed poor outcomes in the CPB group in a range of measures including diffuse alveolar damage (P = 0.009), chest radiograph infiltrate score (P = 0.005), longer intubation time (P = 0.002), longer intensive care unit stay (P = 0.05), and greater incidence of pulmonary reimplantation response (P = 0.03). However, Myles et al. [J Cardiothorac Vasc Anesth 1997;11:177-183] found that only acute postoperative outcomes were significantly worse in their CPB group (P < 0.001); medium- and long-term survival outcomes were not significantly different (P = 0.055). de Boer et al. [Transplantation 2002;73:1621-1627] even found that there was an improved one-year survival rate with CPB use (OR = 0.25, P = 0.038) and that the number of human leukocyte antigen DR (HLA-DR) mismatches influenced this effect. Those papers suggesting no deleterious effects of CPB generally measured similar postoperative outcomes to those mentioned above, with one study also assessing incidence of primary graft failure, which was not significantly different (P = 0.37). We conclude that CPB should continue to be used where clinically indicated for a specific reason (for example, where there is pulmonary hypertension or a requirement for concomitant cardiac repair). However, given that the evidence for using CPB for all elective cases is relatively weak, and the fact that there are strong arguments in the literature for both methods, either approach would be clinically acceptable.