INTRODUCTION — The shortage of available donor organs is the major limiting factor in liver transplantation. Optimal deceased donors are generally young, previously healthy persons who develop a fatal brain injury due to causes such as head trauma, intracerebral hemorrhage, or anoxia. The relative paucity of donor organs has led transplant centers to consider organs from marginal donors.
This topic will review the selection process for deceased donors and examine donor characteristics associated with recipient outcomes. Patient selection for liver transplantation and for living donor liver transplantation is discussed elsewhere.
●(See "Liver transplantation in adults: Patient selection and pretransplantation evaluation".)
●(See "Living donor liver transplantation in adults".)
DONOR EVALUATION
Donation after brain death — The United Network for Organ Sharing (UNOS) provides minimum guidelines for organ procurement. The initial evaluation is typically performed by the local organ procurement organization (OPO). The OPO representative verifies that the prospective donor meets the criteria for brain death. Consent for donation is obtained from the potential donor's next of kin. ABO blood type, height, weight, and chest circumference are obtained because recipient matching is based upon blood type and donor organ size.
Potential donors with contraindications to donation are excluded. These include nonhepatic malignancy (other than primary brain tumor without ventriculoperitoneal shunt). Previously, anti-human immunodeficiency virus (HIV) seropositivity was an absolute contraindication to donation in the United States. The ban was in part due to concern that transplanting HIV-positive organs into patients with HIV that was well controlled could result in the transfer of resistant HIV to the recipient. However, in 2013, a law was passed that ended a ban on transplanting organs from donors with HIV into HIV-positive recipients because of better HIV therapy as well as high waiting list mortality rates for patients with HIV [1]. Although septicemia is usually considered a contraindication to donation, organs from bacteremic donors have been used successfully. A large retrospective study, for example, showed similar 30-day graft and patient survival in recipients of organs from bacteremic and nonbacteremic donors [2].
The OPO representative obtains a medical history, evaluates for a history of substance or alcohol use disorder, and performs a physical examination. Laboratory testing generally includes ABO blood type, complete blood count (CBC), chemistries, prothrombin time (PT), activated partial thromboplastin time (PTT), hepatitis B surface antigen (HBsAg) and anti-hepatitis B core antigen (HBc), anti-hepatitis C virus (HCV), anti-HIV, venereal disease research laboratory (VDRL) or rapid plasma reagin (RPR), and anti-cytomegalovirus (CMV). Blood and urine cultures are performed if the prospective donor was hospitalized for more than 72 hours. OPOs obtain nucleic acid testing (NAT) for HIV and HCV in all increased risk donors to shorten the window period between acquisition of infection and detection by ELISA in order to reduce the risk of transmission to the recipient [3]. Ultrasound imaging or liver biopsy is performed if needed.
The local OPO is responsible for donor maintenance until the time of procurement. Vital signs, intake, and output are monitored. Fluids and vasopressors are given as needed to achieve hemodynamic stability. Antibiotics are provided if necessary.
Living donors — This topic is discussed in detail elsewhere. (See "Living donor liver transplantation in adults", section on 'Evaluation of the living liver donor candidate'.)
DONOR FACTORS IMPACTING RECIPIENT OUTCOME — Multiple donor and transplant-related characteristics associated with recipient outcomes have been evaluated [4-13]. Comparisons among these studies can be difficult since variable clinical endpoints have been measured, recipients had different forms of underlying liver disease, and because donors are often selected based upon recipient characteristics. Clinical endpoints frequently include the following measures:
●Initial graft function
●Primary nonfunction (PNF, ie, graft failure in the immediate postoperative period)
●Graft survival
●Patient survival
Donor factors that have been associated with adverse outcomes include advanced donor age, donor sex or donor-recipient sex mismatch, moderate to marked hepatic steatosis, and donor hypernatremia.
Strategies used to increase available donor livers may affect outcomes. These strategies include adult living donor liver transplantation, donation after circulatory death, the use of hepatitis C virus (HCV)-positive donors for HCV-infected recipients, and use of hepatitis B surface antigen (HBsAg)-positive donors for hepatitis B virus (HBV)-positive and anti-hepatitis B core antigen (HBc)-positive recipients. (See "Living donor liver transplantation in adults" and "Hepatitis C virus infection in liver transplant candidates and recipients".).
Although donor characteristics and technical factors will be discussed individually, a combination of risk factors may interact to affect outcomes in individual patients.
Older age — The use of livers from older donors is now a common practice [14]. However, livers from older donors can have more initial dysfunction due to ischemic or preservation injury, and in recipients with hepatitis C virus (HCV) infection, there is an association of donor age with the development of severe recurrent HCV. Delayed nonfunction may occur, necessitating retransplantation. Use of organs felt to be of good quality on careful inspection [15] and minimizing cold ischemia time [16,17] may help to maximize outcomes when livers are used from older donors.
Several studies have evaluated the relationship between donor age and recipient outcomes, although data are mixed [4,6-8,15,16,18-22]. An illustrative report included 772 patients who underwent liver transplantation at three centers [15]. Older donors were defined as those aged 50 years and older. Laboratory parameters including alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and prothrombin time were higher in recipients with older donors during the first week after transplantation. More importantly, graft survival was reduced at three months in recipients of livers from older donors and this difference persisted to 24 months post-transplant. In multivariate analysis controlling for donor and recipient factors, reduced graft survival was identified only for older donors when the allograft was rated to be poor or fair in quality by the surgeon at the time of harvest. Similar results have been reported in several other series, although the exact donor age associated with worsening outcomes has varied.
Other studies suggest that acceptable outcomes can be achieved with older donors [7,8,16,22-24]. Limiting cold ischemia time and degree of steatosis were hypothesized to be important in optimizing the results of transplantation from older donors. In a study using the UNOS database, the five-year cumulative mortality rates were lower for transplant candidates who accepted a liver from an older donor (≥70 years old) compared with matched controls who declined the same offer (23 versus 41 percent) [22].
Prior to the availability of highly effective direct antiviral agents for HCV infection, the use of livers from older donors was a particular concern for recipients with HCV. A single-center study of 124 liver transplants showed that donor age >60 years was associated with the development of severe recurrent HCV and provided an optimal age cutoff to predict an increased risk of HCV-related graft loss [25].
Hepatic steatosis — Donor livers that appear fatty on inspection are biopsied for histologic determination of fat content. Severe macrovesicular steatosis is associated with primary nonfunction [12,26-31]. Outcomes are more variable when organs with moderate steatosis are used. Illustrative studies have shown the following:
●One study, which analyzed 158 donor liver biopsies, found that moderate fatty change (defined as 30 to 60 percent fat content) was associated with the development of early graft dysfunction [28].
●Another report that categorized donor steatosis as mild (<30 percent), moderate (30 to 60 percent), and massive (>60 percent) found an increased frequency of early graft dysfunction and PNF when donor organs had moderate or massive steatosis [29]. Compared with patients who received livers with mild steatosis, graft survival at one month was slightly lower in those who received livers with moderate steatosis and substantially reduced in those given grafts with massive steatosis.
●A report of 225 consecutive transplants showed that while ≥30 percent donor steatosis was associated with early graft dysfunction, five-year graft survival was similar between patients who received grafts with <30 or >30 percent steatosis [32].
●A retrospective review of the United Network for Organ Sharing Standard Transplant Analysis and Research files examined 5051 liver transplants [33]. At one year, 864 (17 percent) of the grafts had failed. The study found that on multivariable analysis, donor livers with greater than 30 percent macrovesicular steatosis had an increased risk of graft loss (relative risk 1.71). Many transplant centers try to avoid using organs with more than 40 percent fatty infiltration and refuse organs with more than 50 percent fat content [34].
Hypernatremia — Worse outcomes have been reported in liver transplant recipients who receive grafts from donors with hypernatremia. Donor hypernatremia may be a surrogate marker for other factors affecting graft function, including prolonged donor intensive care stay, excessive saline infusion, and negative water balance resulting from aggressive treatment of cerebral edema, and reduced antidiuretic hormone secretion after brain death. In two reports, the rate of graft loss within one month of transplantation was increased when the donor plasma sodium level exceeded 155 mmol/L [35,36]. Other investigators observed a direct relationship between donor serum sodium levels and degree of early graft dysfunction [37]. Most respondents to a survey of the South-Eastern Organ Procurement Foundation liver transplant centers indicated that the maximum donor serum sodium level that they would accept was 160 to 170 mEq/L [34].
Hemodynamic instability — Hepatic blood flow decreases with periods of hypotension and the use of high doses of vasopressors predisposing to ischemic liver injury. Early graft dysfunction was observed when donors had hypotension refractory to dopamine levels exceeding 15 mcg/kg/min [38]. However, the use of high doses of dopamine was not associated with graft dysfunction when the donor's blood pressure was maintained above 90 mmHg.
Donor-recipient mismatch
Sex — Transplantation of livers from female donors was associated with worse outcomes in many, but not all, series [39-42]. Some studies suggest that sex-mismatched transplants in which the liver from a female donor is given to a male recipient may be particularly problematic. As an example, a retrospective evaluation of 994 liver transplants performed over 10 years showed significantly lower graft and patient survival for transplantation of female donors into male recipients compared with other donor-recipient combinations (approximately 56 versus 75 percent two-year graft survival) [40].
A further study of 462 liver transplants with 1.1 to 2.6 years of follow-up found that graft survival was superior with male donors relative to female donors when controlling for other factors [39]. The poorest results were observed with the use of female donors over age 60. A study of pediatric liver transplant patients also documented superior one and five-year graft and patient survival for male-male donor-recipient pairs compared to males who received livers from female donors [41]. The organ allocation system does not take the donor's or recipient's sex into account in distributing livers since other considerations are more important.
ABO compatibility — Livers are routinely matched by ABO blood type (ABO identical), although mismatched organs have been used in extreme circumstances. Mismatched organs may either be ABO compatible (eg, an organ from a donor who is type O going to a recipient who is type B) or ABO incompatible (eg, an organ from an donor who is type A going to a recipient who is type B). A retrospective study of 234 liver transplants found that two-year graft survival was 30 percent in 17 ABO-incompatible emergency transplants compared with 76 percent in 55 ABO-compatible emergency transplants and 80 percent in 162 ABO-compatible elective transplants [43]. Compared with ABO-compatible transplants, humoral rejection, acute cellular rejection, arterial thrombosis, and biliary complications were more common in ABO-incompatible recipients. These data suggest that ABO incompatibility (and not a need for emergency transplantation) was the major reason for graft loss, although the urgent nature of the transplant and severe illness likely had a role as well. Registry data from Europe showed that the risk of mortality was increased nearly two times in recipients of ABO-incompatible livers [44]. However, good outcomes have been reported among recipients with blood type O who receive an organ from a donor with blood type A2 with overall and graft survival rates that are similar to those seen when a recipient with blood type O receives an ABO-compatible organ [45].
Many centers use ABO-incompatible livers in emergency situations such as fulminant hepatic failure when an ABO-identical or compatible organ is unavailable, with the understanding that retransplantation will be required in some patients. In such cases, perioperative plasmapheresis, intensive induction immunosuppression, and prostaglandin E1 administration may reduce the development of severe acute rejection [46,47].
There have also been successful elective transplantations of ABO-incompatible organs from living donors. In a series of 22 recipients of ABO-incompatible organs, overall patient and graft survival were 100 percent after a mean follow-up of 10 months (range 3 to 21 months) [48]. All of the patients received rituximab two weeks prior to transplantation and also underwent plasma exchange with blood group AB fresh frozen plasma every other day prior to transplantation. Plasma exchange transfusion was continued until the IgM and IgG isoagglutinin titers that corresponded to the donor ABO blood group were ≤1:8. During the first two weeks following transplantation, plasma exchange transfusion was repeated if the titers were >1:32.
TECHNICAL FACTORS
Cold ischemia time — Prolonged cold ischemia time (ie, greater than 12 hours) may impact donor organ viability and graft survival. Donor livers are typically preserved in University of Wisconsin storage solution cooled to 0 to 4º C after harvesting. Cold preservation leads to liver injury over time, and the duration of cold ischemia time (CIT) affects recipient outcomes.
Early studies showed that CIT exceeding 18 to 20 hours was associated with increased rates of early graft dysfunction, PNF [28], and need for retransplantation within 14 days [49]. Subsequent reports showed a benefit for maintaining CIT less than 12 hours. Better initial graft function, reduced frequency of PNF, and superior graft and patient survival were observed with CIT less than 12 hours in an analysis that excluded emergency transplantation [50]. Data from a large European registry indicated that the risk of recipient mortality was stable for CIT up to 12 hours and increased with longer preservation times [44]. In multivariate analysis, there was a negative interaction between CIT exceeding 12 hours and recipient age greater than or equal to 60 years, and CIT exceeding 12 hours and status as a previous transplant recipient with graft failure.
Other studies found that CIT exceeding 12 hours was associated with an increased rate of biliary complications, such as intrahepatic strictures [51]. Most centers try to limit CIT to less than 12 hours, particularly in the presence of other donor or recipient characteristics that can adversely affect transplant outcomes.
RISK ASSESSMENT INDICES
Donor risk index — Data from over 20,000 liver transplants were used to develop a predictive model comprised of donor factors known at the time an organ is offered to quantify the risk of graft failure, and this model is known as the donor risk index [52]. The parameters most strongly associated with graft loss include increasing donor age, donation after cardiac death, and use of split/partial grafts. Other risk factors include African American donors, shorter donors, death due to cerebrovascular accident, and causes of brain death other than trauma or anoxia.
Eurotransplant donor risk assessment — Analysis of 4701 deceased donors from Eurotransplant and the European Transplant Registry identified risk factors for graft loss in first time recipients who received a deceased donor liver [53]. Cold ischemia time, highest serum sodium level, cause of donor death, gamma-glutamyl transferase (GGT) level, and female donor sex were predictors of graft loss at three months. In addition, cold ischemia time, GGT, and cause of donor death were associated with 12-month graft loss. The data were used to construct nomograms to allow for rapid assessment of the complex interaction among risk factors in a given donor. When the donor risk index was applied to the dataset, there was limited agreement with the Eurotransplant nomogram (kappa = 0.23). The area under the receiver operating characteristic curve for both predictors was relatively low, indicating the difficulty in defining criteria for extended donors.
APPROACHES TO EXPAND DONOR LIVER SUPPLY
Donation after circulatory death — Patients with an irreversible, catastrophic illness may serve as non-heart-beating donors after withdrawal of care in a controlled hospital setting and after achieving set criteria for cardiac death [54,55]. Such donation is referred to as "donation after circulatory death" (DCD). In the United States, life support is usually withdrawn in the operating room. The patient is observed until the time of death, which is declared by a clinician who is not part of the transplant team. After a waiting period that is generally in the range of five minutes, organ retrieval is initiated with femoral artery cannulation and infusion of cold University of Wisconsin storage solution. Warm ischemia time includes the interval between withdrawal from life support and infusion of University of Wisconsin solution [54].
Use of DCD donor livers could provide a substantial number of needed organs. Outcomes for recipients of DCD donor livers include:
●Patient and graft survival — Studies comparing recipients of organs from DCD donors with standard brain-dead deceased donors have been variable, with some showing similar outcomes, while others suggest decreased graft and patient survival following receipt of a DCD donor organ [54-59]. However, many of the studies are limited by the fact that they were not randomized, potentially leading to disparate outcomes that were not the result of the type of donor organ. One series looked at 2572 liver transplantations, 352 of which were from DCD donors [59]. Compared with recipients of standard brain-dead deceased donor organs, recipients of DCD donor organs had higher three-year graft loss (27 versus 18 percent) and higher three-year mortality (19 versus 14 percent). Another retrospective series with 200 liver transplantations from DCD donors and 1828 liver transplantations from brain-dead deceased donors did not find any significant differences in graft or patient survival between the groups at one, three, or five years [58].
Donor factors associated with graft failure have included indicators of prolonged warm ischemia time, such as a mean arterial pressure lower than 60 mmHg for more than 20 minutes after the withdrawal of life support and longer cold ischemia times (>6 hours in one study) [58,60]. The use of DCD liver grafts with moderate macrosteatosis (30 to 60 percent) was associated with adverse outcomes including primary non-function and early allograft dysfunction [61].
Many centers avoid using DCD livers from older donors (eg, donor age >50 years). However, a study from the UK transplant registry of experienced centers using careful selection of donors and recipients showed no significant differences in 5-year graft survival between DCD donor age >70 years compared with donor age <70 years [62].
Recipient factors associated with reduced DCD graft survival reflected severity of illness, functional reserve, and complexity of the operation. As an example, recipient factors included in the UK-DCD risk score were age >60 years, MELD score >25, and retransplantation [63]. The UK-DCD risk score was developed to match DCD donors and recipients to optimize outcomes [58,60].
●Biliary complications — The use of DCD donors is associated with an increased risk of ischemic cholangiopathy, manifested by diffuse nonanastomotic biliary strictures in the absence of hepatic artery thrombosis. Ischemia-reperfusion injury can cause bile duct injury and subsequent fibrotic narrowing and scarring of the biliary tree after transplantation [64,65]. Indicators of prolonged functional warm ischemia time (eg, longer asystole to cross clamp time) are associated with biliary complications [66].
Single-center studies from transplantation programs that are experienced in the use of DCD livers have reported ischemic cholangiopathy in approximately five percent of recipients of DCD liver grafts [67,68]. However, prior studies including recipients of DCD donor livers reported higher rates of post-transplant biliary complications that ranged from 12 to 60 percent [57,58,69].
Strategies to expand the use of DCD donor livers while minimizing the risk of ischemic cholangiopathy for recipients of such liver grafts include an organ preservation technique using hypothermic oxygenated machine perfusion [70,71]. In a randomized trial of 156 patients who were transplanted with a DCD liver graft, conventional cold storage followed by hypothermic machine perfusion of the liver graft prior to implantation resulted in a lower risk of nonanastomotic biliary strictures within six months after transplant compared with cold storage alone (6 versus 18 percent; risk ratio 0.36, 95% CI 0.14-0.94) [70]. In addition, patients in the machine-perfusion group had lower rates of endoscopic or percutaneous interventions for nonanastomotic biliary strictures (4 versus 14 percent), although statistical analysis was not provided. Notably, the rate of ischemic cholangiopathy in the hypothermic machine perfusion group (6 percent) was similar to rates reported in some studies of DCD donor livers without machine perfusion [67,68,72]. Additional trials are needed to assess the short- and long-term impact of novel preservation techniques such as hypothermic machine perfusion on outcomes for recipients of DCD donor livers. (See 'Machine liver perfusion' below.)
Hepatitis C virus-positive donors — Given the high success rate of direct-acting antiviral (DAA) therapy and limited supply of donor livers, use of livers from HCV-viremic donors for HCV-positive recipients is common. Increasing evidence has suggested that using organs from HCV viremic donors for HCV-negative recipients followed by DAA treatment in the early post-transplant period is an overall effective and safe strategy [73,74]. Outcomes in recipients of HCV-positive liver grafts are discussed separately. (See "Hepatitis C virus infection in liver transplant candidates and recipients".)
Hepatitis B virus-positive donors — Transplantation of organs from donors with serologic markers for past HBV infection has the potential to increase the donor pool, particularly in regions where HBV carriers are frequent (such as the Mediterranean region and Asia). It is generally recommended that grafts from hepatitis B core antibody (anti-HBc)-positive donors should be offered to hepatitis B surface antigen (HBsAg)-positive recipients, although recipients who lack HBV markers may also be eligible provided that they receive antiviral prophylaxis post-transplantation. Antiviral prophylaxis for reducing the risk of donor-related HBV transmission to the recipient is discussed separately. (See "Liver transplantation in adults: Preventing hepatitis B virus infection in liver transplant recipients".)
More controversial is the use of livers from donors who are HBsAg-positive. Transplantation of such grafts has been described [75,76] but should probably not be offered to patients who are HBsAg-negative or to recipients who have concurrent HDV infection since such patients may develop severe HDV-related disease after transplant [77].
Machine liver perfusion — Both hypothermic machine perfusion and normothermic ex-vivo liver evaluation are being studied as techniques to expand the donor pool by limiting the deleterious effects of cold ischemia on extended criteria grafts such as DCD liver grafts and livers with steatosis [70,78-81]:
●Hypothermic oxygenated machine perfusion – Hypothermic machine perfusion has been studied as a method to improve outcomes with use of extended criteria donors and may protect against ischemic cholangiopathy in DCD livers [70,78]. (See 'Donation after circulatory death' above.)
●Normothermic ex-vivo liver perfusion – Preliminary data have demonstrated that normothermic ex-vivo liver perfusion allows for assessment of graft function including metabolic and perfusion parameters and bile flow prior to implantation [79,80,82,83]. Use of a normothermic ex-vivo circuit has the potential to predict graft viability in an effort to minimize primary graft nonfunction with use of extended criteria donor livers.
SPLIT-LIVER TRANSPLANTATION — Splitting livers into right and left lobes for transplantation has been investigated as a way to increase the supply of donor organs. Studies have looked at allocating the split organ to an adult and a pediatric recipient or to two adults.
A working group appointed by the American Society of Transplant Surgeons and the American Society of Transplantation has advocated the institution of a national policy for splitting appropriate donor livers into left lateral and extended right grafts for transplantation into a pediatric and an adult recipient, respectively [84]. Many suitable livers are reduced in size for pediatric transplantation, and are not split with an adult recipient. According to the analysis of the working group, approximately 20 percent of donors could be split, increasing the total number of liver transplant recipients in the United States by up to 1000 annually. Outcomes of in situ liver splitting for adult/child pairs have been comparable to whole graft transplantation.
In a study of 106 split liver transplantations, adult 1-, 5-, and 10-year survival rates were 93, 77, and 73 percent, respectively, with graft survival rates of 89, 76, and 65 percent, respectively [85]. For children, 1-, 5-, and 10-year survival rates were 84, 75, and 69 percent, respectively, with graft survival rates of 77, 63, and 57 percent, respectively.
Splitting the organ between two adults was examined in a retrospective study of 42 patients who received split liver transplantations [86]. One lobe of the liver went to the patient on the waiting list with the same blood type and the highest Model for End-stage Liver Disease score, provided the graft-recipient weight ratio (GRWR) for one of the lobes was at least 0.8 percent. The second lobe went to a recipient with the same blood type in whom the GRWR was 0.8 percent or more. The three-month, one-year, three-year, and five-year survival rates were 76, 71, 69, and 69 percent, respectively. Survival rates were similar to those seen in patients who received living donor transplantations during the same period.
EXTENDED CRITERIA LIVER GRAFT OUTCOMES — The use of marginal or extended criteria liver grafts may lower the risk of mortality on the liver transplant waiting list without impacting patient or graft survival. In an 18-year study of over 2000 liver transplant recipients from a single transplant program, there was no significant difference in rates of one- three- and five-year patient survival for patients receiving marginal liver grafts compared with those receiving standard grafts during the second nine year period [87]. Marginal liver grafts included those with any of the following characteristics:
●Liver donor age >70 years (see 'Older age' above)
●Livers discarded regionally and shared nationally
●Livers from HCV-positive donors
●Livers with cold ischemia time >12 hours (see 'Cold ischemia time' above)
●Livers from donation after circulatory death donors (see 'Donation after circulatory death' above)
●Livers with >30 percent steatosis (see 'Hepatic steatosis' above)
●Livers split between two recipients (see 'Split-liver transplantation' above)
The mortality rate for patients who were waitlisted at the transplant program using marginal liver grafts was lower compared with the national waitlist mortality rate (19 versus 24 percent).
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Liver transplantation".)
SUMMARY AND RECOMMENDATIONS
●The United Network for Organ Sharing provides minimum guidelines for organ procurement. The initial evaluation is typically performed by the local organ procurement organization (OPO). The OPO representative verifies that the prospective donor meets the criteria for brain death. Consent for donation is obtained from the potential donor's next of kin. (See 'Donation after brain death' above.)
●Donor characteristics that are associated with an adverse effect on graft function and/or graft survival include "donation after circulatory death" (DCD), advanced donor age, moderate to marked hepatic steatosis, and donor hypernatremia. (See 'Donor factors impacting recipient outcome' above.)
●The number and severity of donor risk factors is considered in evaluating prospective donors and risk assessment indices have been developed. (See 'Risk assessment indices' above.)
●A shortage of donor livers has led to alternative approaches such as the use of DCD donors and hepatitis C virus (HCV)-positive donors to increase the donor organ supply. (See "Hepatitis C virus infection in liver transplant candidates and recipients".)
Strategies such as hypothermic machine perfusion of DCD donor livers are being studied to expand the donor supply while minimizing the risk of recipient complications (eg, ischemic cholangiopathy). (See 'Approaches to expand donor liver supply' above.)
●Judicious use of extended criteria liver grafts may lower the risk of mortality for patients on the liver transplant waiting list without impacting patient survival or graft function or survival. (See 'Extended criteria liver graft outcomes' above.)
