Lung Transplant Graft Outcomes Relate Back to Donor Care Setting

Surprisingly, there was a difference in graft survival between lungs recovered from hospital-based donor care units (DCUs) and those recovered from independent DCUs, according to an analysis of national Organ Procurement and Transplantation Network (OPTN) records.

Average graft survival reached 1,548 days in lungs from independent DCUs, a significant reduction from the 1,665 days for lungs from hospital-based DCUs (P=0.04), reported Emily Vail, MD, MSc, of the University of Pennsylvania Perelman School of Medicine in Philadelphia, and coauthors of the retrospective cohort study.

“This finding, which was unexpected and refuted the study hypothesis, was consistent across analyses and robust in analyses accounting for transplant program, transplant year, and donor and recipient factors associated with graft and recipient survival,” the group wrote in JAMA Network Open.

“Because many factors impact survival after transplant, we hypothesized that graft survival duration would not differ between lungs recovered from donors in hospital-based vs independent DCUs,” Vail and colleagues noted. They suggested that differences in donor selection, donor management, and relationships with transplant programs may have contributed to divergent graft survival outcomes between facility types.

Based on their OPTN analysis, the likelihood of graft failure over a median follow-up of about 2 years was greater among independent DCUs than hospital-based DCUs (adjusted HR 1.85, 95% CI 1.28-2.65). Adjusted 1-year graft survival was similar between groups.

The upside to independent facilities: a higher lung donation rate (33.5% vs 28.5% with hospital-based DCUs, P<0.001).

“DCUs offer the opportunity to reduce nonuse of donor organs and improve multiple additional aspects of organ donation. In the U.S., only 18 lungs are transplanted per 100 donors, and if national use of DCUs parallels improvements in lung utilization of 71.5%, this could lead to an increase of 31 lungs transplanted per 100 donor organs, which could narrow the gap between candidates in need of a life-saving organ and available organs for transplant,” according to Carli Lehr, MD, PhD, and Kenneth McCurry, MD, both of the Cleveland Clinic, writing in an invited commentary.

Deceased organ donors have been traditionally managed by hospitals that have the intensive care and testing needed to rehabilitate organs, identify transplant recipients, and perform organ recovery surgeries.

Recent decades have seen the advent of centralized DCUs, operated by organ procurement organizations (OPOs), that are dedicated entirely to deceased donors. DCUs can be hospital-based or independent, the tradeoffs depending on the particular operating model. They have been shown to cut costs and increase organ yield but remain challenged by the lack of access to hospital-level support and proximity to hospitals.

“Free-standing DCUs are limited to donation after brain death (i.e., donors who are hemodynamically stable and have variable diagnostic and laboratory capabilities), but donors are cared for by trained OPO personnel and OPO contracted healthcare clinicians (e.g., registered nurses, advance practice nurses, and physicians), and operating room case times are more predictable due to the use of dedicated facilities,” Lehr and McCurry explained.

Contrast that to hospital-based DCUs that “can accommodate donation after circulatory death for donors with full diagnostic capabilities but may experience delays due to competition for ICU and operating room space as well as other resources,” the pair added.

Study investigators and editorialists urged further examination of DCUs and their performance.

Indeed, the present analysis was limited by its retrospective design and inability to account for recipient care delivery variables such as ventilator settings. Researchers also noted that the findings may not be applicable to newly opened DCUs.

“Fundamentally, understanding DCU management and outcomes needs prospective study to address selection bias inherent in decisions to transfer donors to DCUs, to characterize expected but unmeasured differences in operations and resources between DCU models, and to define measures of donor management quality and DCU-specific performance in a rapidly changing system,” Vail and colleagues wrote.

Their analysis utilized OPTN registry data covering U.S. donors, wait-listed candidates, transplant recipients, and deceased donors who underwent recovery procedures from April 26, 2017 to June 30, 2022. Donors were excluded from the analysis if they were unlikely to be transferred to a DCU, which included patients under 16 years old and donors following circulatory death.

Out of the included donors who donated at least one lung, there were 418 who had been managed in 11 hospital-based DCUs and 1,233 from 10 independent DCUs. Both groups were approximately 39% women and averaged 36 years old. The most common cause of donor death across both DCU groups was either intracranial hemorrhage or stroke, representing approximately one in four cases.

Compared to donors in hospital-based DCUs, those from independent DCUs were less likely to be Hispanic (13.1% vs 22.2%), more likely to be white (65.2% vs 51.7%), and less likely to have a documented pulmonary infection (68% vs 77.8%, P<0.001).

Recipients of lungs recovered from independent DCUs had disproportionately higher rates of chronic obstructive pulmonary disease (27.1% vs 21.6%) and less restrictive lung disease (62.3% vs 71%), both of which are linked to better survival after transplantation, according to the investigators. These lung recipients also had significantly longer median 6-minute walk distances prior to their transplant (767 vs 668 ft, P=0.04) and lower median lung allocation scores at transplant match (37.9 vs 39.0, P=0.02).

Study authors also reported that the median donor management time was significantly shorter for donors in independent DCUs compared to those in hospital-based DCUs, at 49 hours and 61 hours, respectively (P<0.001).

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