Predictors of nonuse of donation after circulatory death lung allografts

Abstract

Objective: Despite growing evidence of comparable outcomes in recipients of donation after circulatory death and donation after brain death donor lungs, donation after circulatory death allografts continue to be underused nationally. We examined predictors of nonuse.

Methods: All donors who donated at least 1 organ for transplantation between 2005 and 2019 were identified in the United Network for Organ Sharing registry and stratified by donation type. The primary outcome of interest was use of pulmonary allografts. Organ disposition and refusal reasons were evaluated. Multivariable regression modeling was used to assess the relationship between donor factors and use.

Results: A total of 15,458 donation after circulatory death donors met inclusion criteria. Of 30,916 lungs, 3.7% (1158) were used for transplantation and 72.8% were discarded primarily due to poor organ function. Consent was not requested in 8.4% of donation after circulatory death offers with donation after circulatory death being the leading reason (73.4%). Nonuse was associated with smoking history (P < .001), clinical infection with a blood source (12% vs 7.4%, P = .001), and lower PaO₂/FiO₂ ratio (median 230 vs 423, P < .001). In multivariable regression, those with PaO₂/FiO₂ ratio less than 250 were least likely to be transplanted (adjusted odds ratio, 0.03; P < .001), followed by cigarette use (0.28, P < .001), and donor age >50 (0.75, P = .031). Recent transplant era was associated with significantly increased use (adjusted odds ratio, 2.28; P < .001).

Conclusions: Nontransplantation of donation after circulatory death lungs was associated with potentially modifiable predonation factors, including organ procurement organizations' consenting behavior, and donor factors, including hypoxemia. Interventions to increase consent and standardize donation after circulatory death donor management, including selective use of ex vivo lung perfusion in the setting of hypoxemia, may increase use and the donor pool.

Keywords: donation after circulatory death; ex vivo lung perfusion; lung transplantation; organ procurement; transplantation.

FIGURE 1.

CONSORT diagram of study design. All donors who donated at least 1 organ for transplantation between 2005 and 2019 were identified in the UNOS registry and stratified on the basis of DCD and DBD status. Individual organ-level and donor-level analyses were performed. DCD donors who did not consent for LTx were excluded from further analysis because their lungs could not be evaluated or used for transplantation. DBD, Donation after brain death; DCD, donation after circulatory death.

FIGURE 2.

Forest plot of donor factors leading to use for transplantation. Multivariable regression modeling was fit to assess the relationship between donor factors and use. P/F less than 250 was most strongly associated with nonuse (adjusted OR [AOR], 0.03; P<.001), followed by P/F ratios 250 to 300 (AOR 0.09, P <.001), cigarette use (AOR, 0.28; P <.001), P/F ratios 300–350 (AOR, 0.29; P <.001), and donor age more than 50 years (AOR, 0.75; P = .031). Conversely, the most recent era, 2015–2019, was associated with an increase in use (AOR, 2.28; P <.001). P/F, PaO2/FiO2 ratio; OPO, Organ Procurement Organization.

FIGURE 3.

Leading reasons for DCD lungs not recovered (n = 22,513). Transplant coordinators record these reasons, and organs were most frequently discarded because of poor organ function and concerns about ischemic time. OR, Operation room.

FIGURE 4.

Reason for consent not requested by donation type. Regardless of donation type, OPO approach potential donors and their families to request consent for donation in most cases in the United States. In direct comparison of the 2 donation types, DCD and DBD, consent was not requested in 8.4% of DCD offers, whereas this rate was significantly lower in DBD offers at 2.2% (P<.001). DCD, Donation after circulatory death; DBD, donation after brain death.

FIGURE 5.

A, Proportion of DCD donors donating lungs that resulted in completed transplantation by UNOS region during study period. B, Proportion of lung donors that are DCD by UNOS region during study period. Highest rates of DCD LTx were observed in regions 1, 7, 9, and 10, which corresponded to regions with the highest proportions of DCD. These regions are from the lower half of regions with respect to the total number of lung transplants performed. All regions are shown on the UNOS website: https://unos.org/community/regions/. DCD, Donation after circulatory death; UNOS, United Network for Organ Sharing; DBD, donation after brain death.

FIGURE 6.

Standardized management and optimization of DCD donors within ethical constraints, including the selective use of EVLP, may increase use of DCD organs and expand the donor pool. DCD, Donation after circulatory death; DBD, donation after brain death.