The societal impact of single versus bilateral lung transplantation for chronic obstructive pulmonary disease

Abstract

Rationale: Bilateral lung transplantation (BLT) improves survival compared with single lung transplantation (SLT) for some individuals with chronic obstructive pulmonary disease (COPD). However, it is unclear which strategy optimally uses this scarce societal resource.

Objectives: To compare the effect of SLT versus BLT strategies for COPD on waitlist outcomes among the broader population of patients listed for lung transplantation.

Methods: We developed a Markov model to simulate the transplant waitlist using transplant registry data to define waitlist size, donor frequency, the risk of death awaiting transplant, and disease- and procedure-specific post-transplant survival. We then applied this model to 1,000 simulated patients and compared the number of patients under each strategy who received a transplant, the number who died before transplantation, and total post-transplant survival.

Measurements and main results: Under baseline assumptions, the SLT strategy resulted in more patients transplanted (809 vs. 758) and fewer waitlist deaths (157 vs. 199). The strategies produced similar total post-transplant survival (SLT = 4,586 yr vs. BLT = 4,577 yr). In sensitivity analyses, SLT always maximized the number of patients transplanted. The strategy that maximized post-transplant survival depended on the relative survival benefit of BLT versus SLT among patients with COPD, donor interval, and waitlist size.

Conclusions: In most circumstances, a policy of SLT for COPD improves access to organs for other potential recipients without significant reductions in total post-transplant survival. However, there may be substantial geographic variations in the effect of such a policy on the balance between these outcomes.

Figure 1.

Effect of the interval between available donors on the number of organs transplanted under an allocation strategy of single lung transplantation (SLT) or bilateral lung transplantation (BLT) for chronic obstructive pulmonary disease. * Dashed vertical lines represent median donor interval for blood types A, B, and O across all regions and height quintiles (type AB not shown).

Figure 2.

Effect of waitlist size on the number of organs transplanted under allocation strategies of single lung transplantation (SLT) and bilateral lung transplantation (BLT) for chronic obstructive pulmonary disease.

Figure 3.

Effect of the duration between available donors and waitlist size on the total post-transplant survival of 1,000 potential recipients. * Dashed vertical lines represent median donor interval for bloodtypes A, B, and O across all regions and height quintiles (type AB not shown). BLT = bilateral lung transplantation; SLT = single lung transplantation.

Figure 4.

Effect of variations in the relative benefit of bilateral lung transplantation (BLT) compared with single lung transplantation (SLT) for chronic obstructive pulmonary disease (COPD) and waitlist size on the total post-transplant survival of 1,000 potential recipients. HR = hazard ratio.

Figure 5.

Effect of observed donor availability in each region on the expected post-transplant survival and increased waitlist mortality of 1,000 listed patients associated with adopting a policy of bilateral lung transplantation compared with single lung transplantation for chronic obstructive pulmonary disease. (A) Bloodtype O. (B) Bloodtype A.