Donation after circulatory death may have positive outcomes for LT
Liver donations after circulatory death may experience long warm ischemia time; however, these organs may still lead to positive outcomes for liver transplant recipients, per published findings in Liver Transplantation.
“Donation after circulatory death donors are one of the solutions to expand the donor pool for liver transplantation,” Koji Hashimoto, MD, PhD, department of general surgery, Digestive Disease Institute at Cleveland Clinic, told Healio.com/Hepatology. “Compared to liver transplantation from brain dead donors, [donation after circulatory death] organs are generally considered to have poor quality due to mandatory warm ischemic time during organ recovery.”
To determine if this is a safe organ pool for surgery, Hashimoto and colleagues conducted a retrospective study testing whether hemodynamic trajectories were associated with transplant outcomes in donation after circulatory (DCD) liver transplantation. They phenotyped 87 DCD donors based on hemodynamic trajectory for mean arterial pressure and peripheral oxygen saturation after withdrawing from life support. Donors were divided into three groups: those who gradually declined after withdrawal of life support (group 1), those who maintained stable hemodynamics followed by rapid decline (group 2) and those who declined rapidly (group 3).
“We looked at our data of DCD liver transplant, which showed no correlation between donor warm ischemia time and transplant outcomes. Therefore, we carefully looked at how donors expired from withdrawal of life support to expiration,” Hashimoto said.
Hashimoto said it is a common assumption in many centers that if DCD livers reach a warm ischemia time of more than 30 minutes, they shouldn’t be used.
“[We tend to] believe that if donors don’t expire within 30 minutes, the quality of donor liver is not good enough to maintain liver function after transplantation,” Hashimoto said. “I believe there are many DCD livers that have been discarded because of ‘long’ ischemia time.”
Through the study, Hashimoto said they found that some donors experienced shorter warm ischemia and others had longer; however, one group had different outcomes from these two.
“There was a group of donors who maintained their blood pressure and oxygenation after withdrawal for some time then rapidly declined to asystole,” Hashimoto said. “This category of donors had long warm ischemia time, but transplant outcome was excellent, which we have never known.”
Hashimoto further explained that donor warm ischemia time is not always a good surrogate marker of donor organ quality.
“Even donor warm ischemia time is long, if donors are hemodynamically stable after withdrawal, donor organ quality can be good,” he said. “Therefore, we should not discard DCD livers just because of long warm ischemia time,” adding that the way donors expire should be carefully considered before giving up livers.
Further analyses using Cox proportional modeling showed that hepatocellular carcinoma (HR = 2.53), cold ischemia time (HR = 1.5 per hour) and mean arterial pressure among group 1 were associated with increased risk for graft loss (P = .021). However, it was not with peripheral oxygen saturation (P = .172) or donor warm ischemia time (P = .154).
Despite longer donor ischemia time, the mean arterial pressure and peripheral oxygen saturation in group 2 had similar graft survival compared with the mean arterial pressure and peripheral oxygen saturation in group 3.
“I hope this study helps increase available donor organs to save more patients who need life-saving liver transplantation,” Hashimoto said. – by Melinda Stevens
Disclosure: The researchers report no relevant financial disclosures.