Lung transplant graft outcomes are related to donor care environment

Surprisingly, an analysis of National Organ Donation and Transplant Network (OPTN) records showed a difference in graft survival rates between lungs retrieved from hospital-based donor care units (DCUs) and those retrieved from independent DCUs.

The mean transplant survival for lungs from independent DCUs reached 1,548 days, a significant reduction from 1,665 days for lungs from hospital-based DCUs (P= 0.04), reported Emily Vail, MD, MSc, of the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, and her co-authors on the retrospective cohort study.

“This finding was unexpected and contradicted our study hypotheses, but was consistent and robust across analyses that considered transplant program, year of transplant, and donor and recipient factors associated with graft and recipient survival,” the researchers wrote. JAMA Network Open.

“Because many factors influence survival after transplantation, we hypothesized that graft survival would not differ between lungs retrieved from donors in hospital-based and free-standing DCUs,” noted Baer and colleagues. They suggested that differences in donor selection, donor management, and relationships with transplant programs may have contributed to the differences in graft survival outcomes between facility types.

According to the OPTN analysis, the likelihood of graft failure during a median follow-up period of approximately 2 years was higher in independent DCUs than in hospital-based DCUs (adjusted HR 1.85, 95% CI 1.28-2.65), although adjusted 1-year graft survival was similar between groups.

Advantages of independent facilities: Higher lung donation rate (33.5% in hospital-based DCUs vs. 28.5% in DCUs) P0.001).

“The DCU offers an opportunity to reduce donor organ underutilization and improve multiple aspects of organ donation. In the United States, only 18 lungs are transplanted for every 100 donors; if nationwide use of the DCU were to parallel an improvement in lung utilization rates of 71.5 percent, this could increase to 31 lungs per 100 donor organs, potentially narrowing the gap between candidates needing a life-saving organ and available organs,” said Carli Lahr, MD, and Kenneth McCully, MD, of the Cleveland Clinic. Invited Commentary.

Deceased organ donors have traditionally been managed in hospitals equipped with the intensive care and testing required to rehabilitate the organs, identify transplant recipients and perform organ recovery surgeries.

In recent years, centralized DCUs operated by organ donation organizations (OPOs) for deceased donors have emerged. DCUs can be located within hospitals or stand alone, with trade-offs depending on the particular operating model. Reduce costs and increase organ yields However, lack of access to hospital-level support and proximity to hospitals are challenges.

“Stand-alone DCUs are limited to organ donation after brain death (donors who are hemodynamically stable and do not have constant diagnostic or testing capabilities), but donors are cared for by trained OPO staff or health care providers contracted with the OPO (e.g., registered nurses, advanced practice nurses, physicians), and operating room times are more predictable because they use dedicated facilities,” Lehr and McCurry explained.

In contrast, hospital-based DCUs “can accept organs after circulatory death from donors with full diagnostic capabilities, but there may be delays due to competition for ICU and operating room space and other resources,” they added.

Research investigators and editorial writers urged further investigation of DCUs and their performance.

Indeed, the current analysis was limited by its retrospective design and the inability to take into account patient care delivery variables, such as ventilator settings. The researchers also noted that the findings may not be applicable to newly opened DCUs.

“Fundamentally, understanding DCU management and outcomes requires prospective studies to address selection bias inherent in the decision to transfer donors to a DCU, characterize expected but unmeasured differences in operations and resources across DCU models, and define measures of quality of donor management and DCU-specific performance in a rapidly changing system,” Baile and colleagues wrote.

Their analysis utilized OPTN registry data covering US donors, waitlisted candidates, transplant recipients, and deceased donors who underwent restorative surgery between April 26, 2017, and June 30, 2022. Donors unlikely to be transferred to a DCU, such as patients under the age of 16 and donors after circulatory death, were excluded from the analysis.

Of the donors who provided at least one lung, 418 were managed in 11 hospital-based DCUs and 1,233 were managed from 10 freestanding DCUs. Approximately 39% were female in both groups, and the mean age was 36. The most common cause of donor death across both DCU groups was intracranial hemorrhage or stroke, accounting for approximately one-quarter of deaths.

Compared with donors in hospital-based DCUs, donors in 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 history of lung infection (68% vs. 77.8%, P<0.001).

Recipients of lungs retrieved from independent DCUs had disproportionately higher rates of chronic obstructive pulmonary disease (27.1% vs. 21.6%) and restrictive lung disease (62.3% vs. 71%), both of which are associated with improved post-transplant survival, the researchers say. These lung recipients also had a significantly longer median 6-minute walk distance before transplant (767 feet vs. 668 feet; P= 0.04) and lower median lung allocation score at transplant eligibility (37.9 vs. 39.0; P=0.02).

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