Optimal Utilization of Donor Grafts With Extended Criteria: A Single-Center Experience in Over 1000 Liver Transplants

Over the last 20 years, orthotopic liver transplantation (OLT) has become a routinely applied therapy for an expanding group of patients with end-stage liver disease. Organ availability during that same time period has increased at a much slower rate and appears to have reached a plateau at approximately 6000 liver grafts per year. This disparity has led to a large expansion in the UNOS liver transplant waiting list and a 5-fold increase in deaths while awaiting OLT.1 Multiple strategies for expansion of the donor pool are being pursued concurrently. These include the use of living donors for both pediatric and adult recipients, splitting of cadaveric livers for 2 recipients, and the use of “extended criteria donors” (ECD).2 An accepted precise definition of what constitutes an ECD for liver transplantation remains elusive. Conceptually, the graft from such a donor is at increased risk of early failure (ie, primary nonfunction or delayed graft function) or predisposes to inferior graft or patient survival outcomes. Several single-center studies have attempted to define donor variables that are associated with initial poor function or subsequent graft failure and patient death post-OLT.3–6 However, these studies have exhibited wide variability and seemingly contradictory results in the reported factors that influenced graft function post-OLT. Such variability may have resulted from the type of analysis performed (univariate vs. multivariate), definitions of graft nonfunction, the examined donor parameters, and donor populations that were used by the center.3 Furthermore, operative factors such as warm and cold ischemia and the condition of the recipient may further influence the outcome,7 since transplantation of an extended criteria liver graft in a stable recipient may prove to be successful, while utilization of a similar graft in an urgent patient may be associated with graft failure and death. A collective review of the literature revealed at least 15 donor variables that may be associated with poor graft survival and increased risk of recipient death. Such variables included donor age, sex, race, weight, gender, ABO status, cause of brain death, length of hospital stay, pulmonary insufficiency, use of pressors, cardiac arrest, blood chemistry, cold preservation time, graft steatosis, and donor hypernatremia.3 We recently analyzed outcomes in our single-center experience with 3200 liver transplants and assessed the impact of these factors.8 In that report, multivariate analysis revealed the extended donor characteristics of advanced age and prolonged hospital stay to impact recipient mortality risk. Operative parameters of cold and warm ischemia times (CIT and WIT) also showed independent significance, as did recipient characteristics of age and urgency at time of transplantation. We now examine these extended criteria more closely to assess the actual degree of risk they impart cumulatively to a recipient and for the extent to which they can be scored and “matched” to a recipient to maintain optimum graft and patient survival outcomes.