Single lung transplantation for chronic obstructive pulmonary disease: pulmonary function and impact of bronchiolitis obliterans syndrome.

Chronic obstructive pulmonary disease (COPD) is now the most common indication for single lung transplantation. In long-term follow-up, obliterative bronchiolitis is a major problem. The aim of the present study was to perform a long-term follow-up of the pulmonary function and to examine the effect of development of bronchiolitis obliterans syndrome (BOS). Nineteen patients with end-stage COPD underwent single lung transplantation and were followed regularly with pulmonary function tests, and ventilation and perfusion scintigraphy (mean observation time 29 months). They were divided into two categories, with and without BOS, using the definition recommended by the International Society for Heart and Lung Transplantation working group. A mixed model analysis of variance with BOS as co-variate was used to evaluate its effect on pulmonary function. Spirometry, lung transfer factor for carbon monoxide (TLCO), arterial blood gases and 6-min walk test improved significantly (P < 0.001) from before transplantation to 3 months after transplantation. Nine patients developed BOS. Implied by the definition of the syndrome, forced expiratory volume in 1 s (FEV1) was significantly (P < 0.001) lower for patients with BOS while there was no significant effect of BOS category on TLCO corrected for alveolar volume (VA) or perfusion to transplant. Patients without BOS maintained their pulmonary function, and ventilation and perfusion to transplant for more than 3 yr after transplantation. The present results suggest that decreasing FEV1 accompanied by an unchanged TLCO/VA and pulmonary perfusion support the diagnosis of BOS after single lung transplantation for COPD.