Graft Side-mismatching for Single-lung Transplantation Does Not Affect Outcomes: Role of the Pre-operative Quantitative Lung Perfusion Scan

Background There are concerns about which lung to explant during single-lung transplantation (SLT). Traditionally, a quantitative lung perfusion scan (QLPS) is performed, and the better-perfused lung is retained. Occasionally, there is transplantation with graft “side-mismatching,” where the less-well-perfused lung is retained. We performed a retrospective study of patients undergoing SLT at our institution to evaluate the effects of side-mismatching (according to the QLPS) on graft performance and outcome. Methods We defined graft side-mismatching with a prospectively designed formula using baseline QLPS, and defined patients as either side-matched or side-mismatched. Data on mortality, requirement for cardiopulmonary bypass, relative graft perfusion, lung function and exercise capacity were obtained from institutional databases and patients’ files. Results In a cohort of 114 patients, we defined 97 as having received a side-matched SLT and 17 as having received a side-mismatched graft. After lung transplantation, forced expiratory volume in 1 second (FEV1 ) and exercise capacity improved in both groups ( p < 0.001). Patients with mismatched lungs had significantly higher relative graft perfusion post-operatively ( p = 0.0012). There was no significant difference between the two groups (matched vs mismatched) in mortality, physiologic parameters and need for cardiopulmonary bypass. Conclusions There is no apparent risk to the patient when a side-mismatched lung graft is transplanted. We conclude that side-mismatched lung transplantation appears to be feasible when required.