Organ donation after circulatory death as compared with organ donation after brain death in Switzerland - an observational study.

Abstract

Organ donation after circulatory death (DCD) was reintroduced in Switzerland in 2011 and accounts for a third of deceased organ donors today. Controversy persists if DCD transplants are of similar quality to transplants following donation after brain death (DBD), mainly due to warm ischaemia time DCD organs are exposed to. We compared DCD with DBD in Switzerland. Data on deceased adults who were referred to and approved for organ donation from 1 September 2011 to 31 December 2019 were retrospectively analysed (217 DCD, 840 DBD donors). We compared DCD and DBD donor/organ characteristics, transplant rates of lungs, liver, kidneys, and pancreas, and early liver and kidney graft function in the recipient. The effect of DCD/DBD on transplant rates (organ transplanted or not) and 72-hour recipient graft function (moderate/good vs delayed graft function / organ loss) was analysed using multivariable logistic regression. Among utilised DCD donors, we analysed the effect of functional warm ischaemia time (FWIT) and donor age on 72-hour post-transplant liver and kidney graft function, also using multivariable logistic regression. DCD donors were more often male (64.5% vs 56.8% p = 0.039), presented with heart disease (36.4% vs 25.5%, p <0.001), were resuscitated before hospital admission (41.9% vs 30.7%, p = 0.006), and died from anoxia (41.9% vs 23.9%). Kidney function before transplantation was comparable, lung, liver and pancreas function were poorer in DCD than DBD. Eighty-one and 91% of approved DCD and DBD donors were utilised (p <0.001). Median FWIT in DCD was 29 minutes (interquartile range 25-35). DCD transplant rates ranged from 4% (pancreas) to 73% (left kidney) and were all lower compared with DBD. Seventy-two-hour liver graft function was comparable between DCD and DBD (94.2% vs 96.6% moderate/good, p = 0.199). DCD kidney transplants showed increased risk of delayed graft function or early organ loss (odds ratios 8.32 and 5.05; 95% confidence intervals CI 5.28-13.28 and 3.22-7.95; both p <0.001, for left and right kidney transplants, respectively). No negative effect of prolonged FWIT or higher donor age was detected. Despite less favourable donor/organ characteristics compared with donation after brain death, donation after circulatory death donors are increasingly referred and today provide an important source for scarce transplants in Switzerland. We identified a higher risk for delayed graft function or early organ loss for DCD kidney transplants, but not for DCD liver transplants. When carefully selected and allowed for other risk factors in organ allocation, prolonged functional warm ischaemia time or higher age in donation after circulatory death does not seem to be associated with impaired graft function early after transplantation.