LIVING DONOR LIVER TRANSPLANTATION


Dr. S. Sudheendran MS, FRCS (Eng) (Glas) (Gen)
Transplant Surgeon, AIMS, Cochin

 

What is living-donor liver transplantation?
Living-donor transplantation entails the removal of a portion of the donor’s healthy liver into a recipient who is in need of transplantation. A family member, usually a parent, sibling or adult child, or someone emotionally close, such as a spouse, may volunteer to donate a portion of their healthy liver. This procedure is made possible by the liver’s unique ability to regenerate. After transplantation, the partial livers of both the donor and recipient will grow and remodel to form complete organs.


Is there any other ways of organ donation?
Yes. Cadaveric organ donation from brain-dead patients remains the principal form of donation in most parts of the world. These organs come from patients who die as a result of a head injury, stroke etc who are on a ventilator in a hospital intensive care unit. Although their heart continues to beat and keep their blood circulation going, these patients are clinically dead. Because the ventilator provides oxygen which keeps the heart beating and blood circulating after death, they are called heart-beating braindead donors. If their breathing support machines were stopped, the heart would stop immediately. In these circumstances death is confirmed by brain stem tests. Whilst their heart is beating on the ventilator, their organs can be removed for transplantation into a recipient.


What then is the need for living donor transplantation?
Due to the success of organ transplantation, there are a large number of patients waiting for transplants. Unfortunately there is insufficient number of donors available. Hence most have to wait a long time before a suitable organ becomes available to them. During this waiting period, there is deterioration of the liver disease. In many cases, patients may die without ever getting an organ for transplant.


Is there any advantage of living-donor transplantation?
The principal advantage of living-donor transplantation is that it provides immediate organ availability to those awaiting transplantation. The timing of the transplant operation can be planned and the progression of recipient’s liver disease and its lifethreatening complications can be avoided. Living-donor transplantation offers the possibility of earlier transplantation to those in need, before their health deteriorates to life-threatening status. This is particularly valid in Asia, where for a variety of reasons cadaveric organ donation is extremely infrequent.


How did living-donor liver transplantation begin and how prevalent is it?
Living-donor transplantation was first performed in children as a means to alleviate long waiting times for cadaveric organs. Here less than a quarter of the adult liver needs to be removed for transplantation into a child. This proved to be a very successful procedure all over the world with very little danger to the donor. However adults in need of liver transplantation require a larger segment, as much as half or more of the donor’s liver. This requires a more extensive and complex surgery, with potentially greater risks for the donor. Now adult to adult living donor transplantation has become customary in most parts of the world, but particularly so in Asian countries like Japan, Korea, Taiwan, India etc where cadaveric donation is extremely infrequent.


Who can become a donor?
Potential liver donors are carefully evaluated to select those individuals who can safely donate a portion of their liver which will function immediately. The primary concern throughout the evaluation is the safety of the donor. This means that if transplant physicians estimate the risk of death for a donor could exceed 1%, that person would not be permitted to donate. General criteria for liver donation include:
• good general health.
• blood type compatible with recipient’s blood group.
• having an altruistic motivation for donating.


What are the major risks in donating?
Risks to the donor include, but are not limited to, bleeding, infection, bile leakage, and possible death. This is more common when the right lobe of the liver (comprising 60% of total liver volume) is used for donation. When the recipient is a small adult, the left lobe of the liver from the donor might suffice and in such cases the complication rates are extremely low. For transplantation into children, even smaller portion of the liver is required from the donor, decreasing the complication even further, although not totally eliminating them. In most cases, these complications settle down spontaneously. Nevertheless in some cases additional operation may even be necessary. Overall the risk of complication is about 10% and the risk of death is less than 1%.


What is involved in the donor evaluation process?
A living-donor candidate must complete the following evaluation process to determine if they can safely donate:
• The first testing determines if the donor’s blood type is compatible with that of the recipient. Additional blood tests are performed to test for healthy functioning of the donor’s liver, kidneys and thyroid, and to screen for exposure to transmittable viruses such as hepatitis and HIV, the virus that causes AIDS.
• Abdominal ultrasound testing is performed to screen for abnormalities of the liver and other abdominal organs and blood vessels.
• CT scans and Magnetic Resonance Imaging (MRI) are performed to create detailed anatomical “road map” of the donor’s internal organs to decide how much of the liver would be required for the transplant and to aid the surgery.
• Usually additional testing, such as pulmonary function testing, echocardiogram, exercise stress testing etc is necessary to authenticate the well being of the donor.
The standard time required to complete the donor evaluation process is two to four weeks. If necessary, however, it can be completed in as little as 48 hours.


What happens during donor surgery?
Depending on which part of the donor’s liver is removed, the incision is either straight up and down, or in the shape of an inverted “T.” Typically for right lobe donation, the gallbladder needs to be removed. The donor’s liver is carefully split into two segments and one portion is removed for the recipient. The surgeon then closes the incision with self-absorbing sutures. The liver begins to heal and regenerate itself, generally taking six to eight weeks for full regeneration.


How long does the donor remain hospitalized?
Typically, a donor remains in the hospital from five to ten days after surgery. Donors spend their first night after surgery in the Surgical Intensive Care Unit for close monitoring by specialized nursing staff. The following day, they are usually transferred to the general surgical floor where the nurses are specifically experienced in caring for liver donors. Donors are encouraged to get out of bed and sit in a chair the day following surgery, and to walk the corridors as soon as they are able to.


How long before the liver donor is fully recovered?
Every donor’s recovery time is different but, typically, donors spend four weeks recuperating after surgery. In the month following discharge from the hospital, donors return weekly for outpatient monitoring. Individual recovery rate and the type of occupation dictate how soon a donor can return to work, but it commonly averages three to six weeks.