Right single lung transplantation or double lung transplantation compared with left single lung transplantation in chronic obstructive pulmonary disease

Abstract

Background: Although single and double lung transplantation outcomes for chronic obstructive pulmonary disease (COPD) have been investigated, right and left single lung transplants have never been rigorously compared to evaluate disease-specific differences. Single lung transplants for COPD often have hyperinflation of the contralateral native lung, which may be more pronounced in left lung transplants.

Methods: Using the United Network for Organ Sharing registry, we conducted a retrospective cohort study of 5,585 adults who underwent lung transplantation for COPD from May 4, 2005 to June 30, 2017. Subjects were followed until March 2019. Post-transplant survival was compared using Cox proportional hazards and Royston and Parmar's flexible parametric survival models. We adjusted for donor and recipient factors with known or plausible associations with survival.

Results: Lung transplant recipients who received a left single lung transplant for COPD had an increased risk of post-transplant death when compared with those who received a right single lung transplant for COPD (hazard ratio [HR]: 1.24, 95% CI: 1.08-1.48, p = 0.002). Survival did not differ significantly between double lung transplant and right single lung transplant recipients (HR: 0.88, 95% CI: 0.77-1.02, p = 0.086). Adjusted 5-year survival was 57.8% (95% CI: 55.7-60.1) for double lung recipients, 56.7% (95% CI: 55.4-58.0) for right single lung recipients, and 50.9% (95% CI: 47.2-55.0) for left single lung recipients.

Conclusions: In COPD, right single lung transplantation was associated with improved post-transplant survival compared with left single lung transplantation, and no significant difference in post-transplant survival compared with double lung transplantation was found. In light of the ongoing donor lung shortage, preferential allocation of right single lungs to patients with COPD should be considered.

Keywords: double lung transplant; lung allocation policy; lung transplant; post-transplant survival; single lung transplant.

Figure 1

Flow chart of inclusion/exclusion criteria. A1ATD, alpha-1 antitrypsin deficiency; COPD, chronic obstructive pulmonary disease.

Figure 2

Survival post lung transplantation. (a) Kaplan–Meier unadjusted survival curve. (b) Adjusted Cox proportional hazards survival curve. Covariates include age, blood type, ethnicity/race (black, white, Hispanic, other), gender, LAS at the time of transplantation, pulmonary hypertension, lung listing preference, donor-to-recipient pTLC ratio (COPD if pTLC ratio ≥ 1.1), and transplantation center. COPD, chronic obstructive pulmonary disease; LAS, lung allocation score; pTLC, predicted total lung capacity.

Figure 3

Adjusted survival for double lung, right single lung, and left single lung transplantations using flexible parametric survival model adjusting for time-dependent effects. Covariates include age, blood type, ethnicity/race (black, white, Hispanic, other), gender, LAS at the time of transplantation, pulmonary hypertension, lung listing preference, donor-to-recipient pTLC ratio (COPD if pTLC ratio ≥ 1.1), and transplantation center. COPD, chronic obstructive pulmonary disease; LAS, lung allocation score; pTLC, predicted total lung capacity; RP, Royston and Parmar.