Liver transplantation is a life-saving procedure for individuals with end-stage liver disease or acute liver failure. Availability is severely limited by the scarcity of donor organs, as demand consistently outweighs the supply, leading to long waiting lists. Livers for transplant come from two primary sources: deceased donors (individuals who have recently died) and living donors (healthy, consenting adults who donate a portion of their liver). The criteria for donation are rigorous, designed to maximize the safety of both the donor and the recipient and ensure the best possible transplant outcome.
Deceased Donor Eligibility
The majority of liver transplants utilize organs from deceased donors, whose suitability is determined by medical criteria. Donors are categorized based on how death is declared: Donation after Brain Death (DBD) or Donation after Circulatory Death (DCD). DBD donors have suffered an irreversible cessation of all brain function, while DCD donors are those whose heart and breathing have permanently stopped.
Medical teams assess the donor’s overall health, looking for conditions that could compromise the organ, such as severe infections or malignancy. A significant factor is the degree of fat accumulation, or steatosis. Livers with greater than 30% macrovesicular steatosis are considered less suitable, especially for critically ill recipients, due to the increased risk of initial poor function.
Consent is obtained through a donor registry designation or authorization provided by the family. Timing is sensitive for DCD livers, which must be recovered quickly after circulatory arrest to minimize warm ischemia time (the period without oxygenated blood supply). Controlled DCD, where life support is withdrawn in a hospital, allows for a more predictable recovery. Livers from older donors may be used but require careful matching with a less-ill recipient to mitigate complication risks.
Living Donor Medical Requirements
Living donation offers an alternative to the waiting list and requires excellent physical and psychological health to ensure donor safety. Potential donors must generally be between the ages of 18 and 60. Younger individuals are not considered mature enough for fully informed consent, and older donors face a higher risk of surgical complications. Donors must be free of major chronic illnesses, including severe heart or lung disease, active cancer, or poorly controlled diabetes.
The transplant team focuses on ruling out pre-existing liver disease, such as hepatitis or cirrhosis. The amount of fat in the liver (steatosis) is measured, often through imaging or biopsy, with a maximum acceptable limit typically around 10% to 20%. A high Body Mass Index (BMI), usually above 30 to 35, can disqualify a donor because obesity is associated with excessive liver fat, increasing complication risks for the donor and the graft.
The potential donor must have a compatible blood type with the recipient. Surgeons use imaging to confirm that the donor’s liver anatomy is favorable for a safe operation. Since the liver regenerates, the remnant liver volume in the donor must be at least 30% to 35% of the original size to sustain normal function after the procedure.
The Living Donor Screening Process
The evaluation for living liver donation is a deliberate, multi-phase process designed to protect the donor.
Psychosocial Assessment
The process begins with extensive education and a thorough psychosocial evaluation conducted by a social worker or mental health professional. This assessment confirms the donation is voluntary, that the candidate understands the significant risks, and that they have a strong support system for recovery.
A separate professional, the Independent Living Donor Advocate (ILDA), protects the donor’s interests. The ILDA ensures the donor is not pressured and that their well-being is prioritized over the recipient’s need. Financial stability is also reviewed; while evaluation and surgery are covered, costs like lost wages or travel during recovery are not always reimbursed. The candidate must be in a sound mental state to cope with the stress of surgery and recovery.
Medical and Surgical Mapping
Detailed medical and surgical assessments follow, involving sophisticated radiological studies like CT scans and MRIs. These imaging tests map the precise vascular and biliary anatomy of the liver, which is highly variable. Surgeons use these scans to calculate the expected volume of the portion to be donated and the projected volume of the segment that will remain in the donor.
The evidence from the medical, surgical, and psychosocial evaluations is presented to a multidisciplinary team for a final review. This team, which includes surgeons, hepatologists, social workers, and the ILDA, collaboratively determines if the donation can proceed safely. The candidate can withdraw consent at any point during this rigorous evaluation without consequence.