Living liver donation involves transplanting a segment of the liver from a healthy, living person to a recipient. This is possible because the liver is the only human organ capable of full mass regeneration. The donated segment immediately begins to function in the recipient, while the remaining portion in the donor regrows to nearly its original size. This regenerative ability allows a healthy person to safely donate a life-saving organ portion.
The Unique Regenerative Capacity of the Liver
The liver’s ability to regrow is a biological feature that makes living donation feasible without compromising the donor’s health. This process is not the creation of new tissue from scratch, but rather a rapid enlargement of the remaining liver cells. The primary mechanism involves hypertrophy, where existing hepatocytes increase in size, and hyperplasia, where the cells divide to increase in number. The remaining liver tissue begins to regenerate almost immediately after the segment is removed. This rapid growth response is triggered by various factors, including changes in blood flow and the concentration of growth-promoting substances like bile acids in the bloodstream.
Determining the Amount of Liver Donated
The quantity of liver tissue removed during a living donation is precisely calculated to ensure both the recipient receives enough to survive and the donor retains a safe minimum volume. The amount donated is measured by weight and volume, typically ranging from 25% to 60% of the donor’s total liver mass. For a child, the smaller left lateral segment, which is about 20% of the liver, may be sufficient for transplant. Donation to an adult recipient usually requires a larger segment, often the entire left lobe or a portion of the larger right lobe, which can constitute 40% to 60% of the liver. Surgeons use advanced imaging like CT and MRI scans to calculate the Standardized Liver Volume (SLV), ensuring the donor retains a minimum of 30% to 35% of their original liver volume to prevent post-operative complications.
The Living Donor Surgical Procedure
The donation process begins with an extensive pre-surgical evaluation, which includes detailed CT and MRI scans to map the liver’s anatomy and calculate volumes. Blood tests, cardiac evaluations, and psychological assessments are also performed to confirm the donor is in excellent health. The actual hepatectomy, or partial liver removal, is a major operation performed under general anesthesia, usually lasting several hours. The surgical technique can be open, involving a large abdominal incision, or a minimally invasive approach using laparoscopic or robotic tools. The surgeon meticulously divides the liver, blood vessels, and bile ducts to separate the segment intended for transplantation.
Following the removal of the donated portion, the donor is monitored closely in the hospital for approximately five to seven days. During this immediate post-operative period, pain is managed with medication, and the medical team ensures all biological markers indicate the remaining liver is functioning properly.
Donor Recovery and Long-Term Health
After discharge from the hospital, the donor’s recovery progresses steadily. The liver typically regrows to 80% of its original size within the first six to twelve weeks post-surgery. Full mass restoration is generally complete within three to six months, though liver function often normalizes much sooner. Most donors are able to return to work and resume their normal daily activities within one to three months following the procedure. Long-term studies show that the vast majority of living donors experience a return to their pre-donation health and quality of life.