Introduction

Organ donation is the act of giving an organ to someone else who needs a transplant. Organ donation can generally be divided into two types: living donor transplants and deceased donor transplants. This article will focus on living donor transplants. 

In the UK in 2022, more than 4000 organs were donated, 822 of which came from living donors. The vast majority of these were kidney and liver transplants, although it is possible to donate parts of the lung and intestines as a living donor.

Having an organ transplant can improve the quality of, or even save, a person's life.¹ 

What is a living organ donation?

Deceased organ donors can be classified as either deceased through brainstem death (DBD) or deceased through cardiac death (DCD). DBD organ donors are those who have been declared as having no brain activity but still have functioning organs. In contrast, DCD donors are those whose hearts have stopped beating.

Although the majority of transplants in the UK come from deceased donors, only around 1% of people who pass away each year die in a way that means that their organs are suitable for transplant. This makes living donor organ donation all the more important.²

Generally, with deceased organ donation, the transplant is more difficult to plan for, meaning that patients are often called in for a transplant in an emergency. Organs may spend a longer amount of time outside of the body without an oxygen supply, which can sometimes make the transplant less successful or take longer to start working properly.³

With living donors, the person donating the organ is still alive. As such, it is generally much easier to plan for the procedure, and the donor and the recipient generally undergo the procedures in tandem at the same hospital. This makes the procedure much safer, and the transplanted organ typically spends much less time outside of the body, which increases the chances of a successful transplant.⁴

Living donors may be related or unrelated to the recipient. Some people even choose to donate their organs to patients they do not know altruistically. Generally, living donors who are related to the patient are a better genetic match. which reduces the chances of an organ being rejected by the recipient's body.⁵

What kinds of organs can be donated?

Kidneys

The main organ donated in the UK by living donors is a kidney. We are born with two kidneys, but healthy people can live a normal life with only one kidney after the other is donated for transplant. Donating a kidney does not increase the risk of the donor getting kidney failure and requiring a transplant. This is one of the reasons why kidney donation is the most common kind of living donor transplant. 

The vast majority of people who receive a kidney transplant already have end-stage renal failure and have been on dialysis for some time. Although dialysis does the job of the kidneys, it can have a huge impact on a patient’s quality of life and, unfortunately, comes with a high risk of mortality. When someone gets a transplant before they need dialysis, it is called a pre-emptive transplant and it has been shown to result in better long-term health and improved quality of life for the patient.⁶

Liver

Some people are also able to donate parts of their liver – this is known as a reduced or split liver. A reduced liver is when only a part of the liver is used, whereas a split liver is where either a whole right or left liver lobe is used. Although we only have one liver, if enough of it is left in the body after the transplant, it is able to grow back into a full-sized liver over time.⁷

Lung

It is possible to donate part of a lung as a living donor, but this is very rarely done in the UK. In these types of operations, a recipient will receive the lower part of the left lung from one donor and the lower part of the right lung from another.⁸

Intestine

An intestinal transplant is generally quite a rare procedure. Most intestinal transplants are deceased donor transplants. Unlike liver and kidney transplants, the supply of potential intestinal transplants currently hugely outweighs the demand. As such, it is rare that living donors donate segments of their intestines.⁹

The donation process in the UK

Those who are over 18 and in good health are typically able to be considered eligible to become living donors.  

Generally, people choose to donate their organs to close friends and family members. Nevertheless, sometimes people do choose to donate to people they do not know. Sometimes, people will not be a good genetic match for the person they want to donate their organs to. If that is the case, they can choose to enter a two-way exchange or pooled donation scheme. For example, the kidney-sharing scheme in the UK matches kidneys with other people who have chosen to enter the scheme. The end goal of this scheme is that everyone in the scheme is found a suitable, unrelated donor and receives a transplant. 

People who have expressed interest in organ donation will generally undergo a number of assessments. These include: 

• Height and weight
• Blood pressure checks
• ECGs
• Blood tests
• Scans
• Blood grouping/genetic testing 
• Psychological assessments 

All of these tests are to ensure the donors are a suitable match for the recipient. 

In the UK, if the transplant is likely to go ahead, donors must legally meet with an independent assessor trained by the Human Tissue Authority. This is to ensure that:

• You are who you say you are
• You are not being forced to donate an organ
• You understand the process and what the operation will involve¹⁰

Risks of living organ donation

As with any surgical procedure, donating an organ comes with its risks. The specific risks associated with living organ donation vary by organ type but generally include short-term risks such as: 

• Pain
• Bleeding 
• Infection 

There can also be risks of long-term health issues, as well as possible psychological effects. 

Donors may experience anxiety, depression and conflicts within their families. Decision-making is often influenced by immediate family needs, which can potentially lead to regret or distress if complications arise post-transplant or if the recipient’s outcome is poor.^11,12 

Some argue that the act of donating an organ poses ethical questions since it involves subjecting a healthy individual to risks in order to benefit another person.¹³

Kidney

Generally, healthy individuals are able to donate one of their kidneys to others without putting themselves at a higher risk of end-stage kidney failure. A 2015 study showed that the absolute risk of a donor experiencing end-stage kidney failure is less than 1% in the 15 years after donation. There is a potential increase in diseases associated with poorer kidney function, such as raised blood pressure and gout.¹⁴

Donors are rigorously assessed prior to donating a kidney, especially if they are donating to a relative with a form of kidney disease that may have a genetic component. 

Liver

Liver donation poses a greater risk to the donor than kidney donation. The risk tends to be greater when an adult is donating to another adult. This is because typically a larger portion of the liver needs to be donated. The surgery itself can pose a significant risk to the donor, with risk of bleeding, bile leaks and long recovery times – donors typically have to spend a few days in the intensive care unit after their surgery.  

However, in a 2015 study, most living liver donors reported that after six years their health was the same or better than it was before they donated.¹⁵

Lung 

Lung donors can experience decreased lung function and complications related to the surgical sites (such as infection and air leaks. The psychological impact of lung donation is reported to be high, particularly if the transplant fails.¹⁶ 

Intestine

Donors of intestinal segments may face complications such as bowel obstruction, infection, and adverse effects on nutrient absorption, leading to nutritional deficiencies and significant lifestyle changes.¹⁶

Summary

A living donor transplant is the transfer of an organ or a part of an organ from a living individual (donor) to a person in need (recipient). A living donor transplant has several benefits. For example, the procedure can be planned and is safer in general. That is because the organ or organ part in question only remains outside of the body for a short time. This increases the chance of a successful transfer. Living donors can be related or unrelated to the recipient. However, the higher the genetic match, the better the chances a recipient’s body will not reject the donated organ/organ part. The kidney is the only organ that can be given by a living donor in its entirety. This is because we usually have two kidneys. As far as other organs like the liver, the lung and the intestine are concerned, only parts of them can be safely acquired from living donors. A living donor transplant involves certain risks for the donor. These include pain, bleeding and infection. While living organ donation can be life-saving, it comes with considerable risks that should be carefully considered. Both donors and recipients must be fully informed about these potential risks and the long-term implications of the donation process.