Small bowel transplant
A small bowel (intestinal) transplant is an operation to replace a diseased or shortened small bowel with a healthy bowel from a donor.
It is a complicated and highly specialised operation that is not commonly performed, although the number of procedures carried out has increased in recent years.
Currently, around 15-20 small bowel transplants are performed each year in the UK.
These procedures are carried out at four specialist centres – Birmingham Children’s Hospital, Addenbrooke’s Hospital in Cambridge, John Radcliffe Hospital in Oxford and King's College Hospital in London.
Why small bowel transplants are carried out
A small bowel transplant is an option for children and adults whose bowel has stopped working properly and who are being fed by total parenteral nutrition (TPN). This is where a person requires all their nutrition to be given through a drip into a vein because their bowel is unable to absorb nutrients from any food they eat.
While many people needing TPN can have this treatment at home without experiencing any significant problems, the long-term use of TPN can lead to serious complications such as liver disease and repeated infections.
A small bowel transplant may be considered when the person has a serious problem with their bowel, but have developed complications from TPN or are unable to tolerate this form of feeding.
Before having a small bowel transplant, you will need a transplant assessment. This involves tests and conversations with a transplant team to check if you are suitable for the procedure.
If you are suitable, you will be placed on a national waiting list until suitable organs from a recently deceased donor become available. You may be contacted at any time by the transplant team, day or night.
How long you have to wait will depend on your blood group, the availability of donors and how many urgent cases are on the list. On average, people wait just under six months for a small bowl transplant.
In some cases, it may be possible for a family member to donate a section of their bowel for transplantation, without you needing to be placed on the waiting list.
A small bowel transplant is a complicated and difficult operation that takes, on average, around 8-10 hours and is carried out under general anaesthetic.
During the procedure, the surgeon will remove the bowel and connect the transplanted bowel to your blood vessels and digestive tract. They will also form an ileostomy, where part of the small bowel is diverted through an opening in the tummy, called a stoma.
The stoma will allow digestive waste to pass out of your body into an external pouch, and lets the transplant team easily assess the health of your transplanted bowel. Although it is not always possible, the ileostomy may be reversed a few months later.
After the operation
Recovering from a small bowel transplant can take a long time, and you'll probably need to stay in hospital for at least four to six weeks.
While in hospital, you will receive medication to reduce the risk of your body rejecting the new organ; these are known as immunosuppressants. You will be slowly weaned from TPN to eating a normal diet.
After leaving hospital, you'll need to continue taking immunosuppressant medication and have regular check-ups for the rest of your life.
Although medication and regular check-ups will be needed indefinitely, a small bowel transplant can allow you to live as normal a life as possible – including working, enjoying hobbies and living independently.
However, due to the risks of surgery and the general poor health of people who are considered for a small bowel transplant, some people will die within a few years of their operation.
Current figures for transplants carried out in the UK between January 1998 and December 2013 show that:
after 90 days – 84% of adults and 88% of children are still alive
after one year – 76% of adults and 72% of children are still alive
after five years – 62% of adults and 51% of children are still alive
However, the outlook for small bowel transplants carried out now is likely to be better than these figures suggest, as medical knowledge and techniques are constantly improving.
Why small bowel transplants are carried out
A small bowel transplant may be considered for people with bowel failure who develop complications from total parenteral nutrition (TPN).
Bowel or intestinal failure means a person's bowel isn't able to absorb enough nutrients from food. It is most often caused by either short gut syndrome or a non-functioning bowel.
Short gut syndrome, also known as short bowel syndrome, is where a large part of the small bowel is missing, removed or damaged. It can be caused by:
volvulus (twisting of the bowel)
gastroschisis (a birth defect where some of a baby's bowel develops outside the body)
necrotising enterocolitis (where part of the tissue of the bowel dies)
surgery to remove a large section of bowel to treat Crohn's disease or bowel cancer
Most people with short gut syndrome will need some parenteral nutrition (when nutrients are provided directly into a vein). In many cases, this can be given at home without causing any significant problems.
However, if you've received all of your nutrition via TPN for a long period of time, there's a risk that potentially serious complications could develop. If this is the case, a small bowel transplant may be considered.
Total parenteral nutrition (TPN)
TPN is where a person receives all their nutrition in liquid form intravenously – i.e. through a tube (catheter) inserted into a vein in the arm, groin, neck or chest.
In some cases, long-term TPN can lead to complications, which can sometimes be life-threatening. These problems include:
running out of suitable veins to insert the catheters
an infection where the catheter is inserted, which can spread through the bloodstream and lead to sepsis
A combined liver and small bowel transplant or multiple organ transplant (multivisceral transplant) may be considered for people who have developed liver disease or who have problems affecting several organs.
What happens before having a small bowel transplant
If you are being considered for a small bowel transplant, you will be referred for a transplant assessment. Tests will be carried out to see whether a transplant is the best treatment for you.
An in-depth assessment will need to be carried out before deciding whether you should be placed on the waiting list for a transplant.
This will usually involve a number of different tests carried out over a period of one to three weeks. Depending on your overall health, you may need to stay in hospital while these tests are carried out, or you may only need to attend a series of outpatient appointments.
Tests you may have include:
blood tests – to check your liver function, electrolytes, kidney function and to see if you have any serious infections, such as HIV or hepatitis
a number of scans – such as a chest X-ray, a computerised tomography (CT) scan of your tummy (abdomen) and an ultrasound scan of your liver
an endoscopy – where a long, thin tube with a camera on the end is inserted into your rectum to examine the inside of your bowel
lung function tests
During the assessment, you will have the chance to meet members of the transplant team and ask questions. The transplant co-ordinator (the person organising your transplant, who you will have most contact with) will talk to you and your family about what happens, and the risks involved in a small bowel transplant.
When the assessment is complete, a decision will be made on whether a small bowel transplant is the best option for you.
Why you might be unsuitable for a transplant
Not everyone considered for a small bowel transplant is suitable. For example, it may be unsuitable for you because:
you have cancer that has spread to several areas of your body
you have a serious illness with a very poor outlook
you require breathing support with a ventilator (a machine that moves oxygen-enriched air in and out of your lungs)
you are over 60 years of age
you haven't acted on your doctor's advice (to quit smoking, for example), haven't taken the medication prescribed for you or have missed hospital appointments
Waiting for a transplant
If you are felt to be suitable for a small bowel transplant and are unable to receive a living donation from a family member, you will be placed on the national waiting list.
If you are on the waiting list, the transplant centre will need to contact you at short notice as soon as organs become available for transplantation, so you must inform staff if there are any changes to your contact details.
You will usually be contacted before the transplant surgeons have had a chance to assess the suitability of the donated organs, which means there is a chance you may be called in several times for "false alarms" before the operation is eventually carried out.
The length of time you wait will depend on your blood group, donor availability and how many other patients are on the list (and how urgent their cases are). On average, people wait just under six months for a small bowl transplant.
While you wait, you will be cared for by the doctor who referred you to the transplant centre. Your doctor will keep the transplant team updated about changes to your condition. Another assessment is sometimes necessary to make sure you are still suitable for a transplant.
Your transplant team
If you are being considered for a small bowel transplant, you will be in contact with several different people who make up your transplant team. This team may include a:
transplant nurse specialist
How a small bowel transplant is performed
There are different types of small bowel transplant operation that may be recommended, depending on your individual circumstances.
The main types of transplant procedure are:
small bowel transplant only – recommended for people with bowel failure who do not have liver disease
combined liver and small bowel transplant – recommended for people with bowel failure who also have advanced liver disease
multiple organ (multivisceral) transplant – although it's not often carried out, this can be recommended for people with multiple organ failure, and involves transplanting the stomach, pancreas, duodenum (the first section of small bowel), liver and small bowel
What happens during surgery
A small bowel transplant is a complicated and highly specialised operation. It is performed under general anaesthetic and takes around 8-10 hours to complete, although it can take longer.
After removing your diseased bowel, your blood vessels are connected to the blood vessels of the transplanted bowel, in order to supply it with blood. The transplanted bowel is then connected to your digestive tract, or to what is left of the bowel.
The surgeon will form an ileostomy (where part of the small bowel is diverted through an opening in the tummy, called a stoma). After the operation, the ileostomy allows digestive waste to pass out of your body into an external pouch, and lets the transplant team assess the health of your transplanted bowel.
Depending on your health and the operation's success, the ileostomy may be closed a few months after the operation and the bowel reconnected. However, this is not always possible.
Donating a section of small bowel
It is sometimes possible to carry out a small bowel transplant using a section of bowel donated by a living family member.
In these cases, the donor will need to have an operation during which the donated part of bowel is removed and the remaining sections of bowel are connected together.
Recovering from a small bowel transplant
Immediately after a small bowel transplant, you will be taken to the intensive care unit (ICU) and carefully monitored, so the transplant team can check your body is accepting the new organ.
While in the ICU, you will have various tubes in your veins to provide medications and fluids, and you will be attached to monitoring equipment.
You may also have regular bowel biopsies, where tissue samples are taken using the opening in your tummy created by the surgeon. Alternatively, you may have an endoscopy, where a long, thin tube with a camera on the end is inserted into the opening in your tummy, to examine the inside of your bowel.
The transplant team can determine whether your body is rejecting the bowel from your biopsy results. If it is, additional treatment with medications to suppress your immune system (immunosuppressants) will be given.
Once you have started to recover, you will usually be transferred to a specialist transplant ward, where you will continue to be given painkillers, immunosuppressant medication and nutrition through a tube into a vein (parenteral nutrition).
Over time, the vast majority of people are able to move from parenteral nutrition to eating a normal diet fed through the mouth.
How long it takes to recover from a small bowel transplant depends on whether you also had any other organs transplanted at the same time. Overall, the recovery period is generally longer than for most other types of organ transplant.
On average, people who have a small bowel transplant are discharged from hospital after around four to six weeks.
If you live a long distance from the hospital, you may need to stay in nearby hospital-provided accommodation for a month or two after you are discharged, so you can be monitored carefully and treated quickly if any problems develop.
After leaving hospital
On leaving hospital, you will be given immunosuppressant medication to help prevent your body rejecting the transplant. This medication will need to be taken for the rest of your life.
For the first few weeks or months after leaving hospital, you will need to continue having regular blood tests and endoscopies, but these will be carried out less often over time. Eventually, you may only need to see your surgeon once year and have blood tests every few months.
Although it can take a long time to make a full recovery from a small bowel transplant, and there is a risk of potentially serious complications, the aim of the operation is to eventually allow you to live as normal a life as possible – including working, enjoying hobbies and living independently.
Risks of a small bowel transplant
As with all types of surgery, there are risks associated with having a small bowel transplant.
Better anti-rejection drugs, refined surgical procedures and a greater understanding of the body's immune system have increased the number of successful bowel transplants and improved survival rates in recent years.
However, potentially serious complications can still occur, such as:
heart and breathing problems
infection of the small bowel – such as an infection by the cytomegalovirus (CMV)
blood clots (thrombosis)
post-transplant lymphoproliferative disorder (PTLD) – where the Epstein-Barr virus infects white blood cells, which can lead to abnormal growths throughout the body and multiple organ failure, if not promptly treated
rejection of the donor organ (see below)
problems associated with the long-term use of anti-rejection medication – such as an increased risk of infections, kidney problems and certain types of cancer
Due to these risks and the overall poor health of people who are considered for a small bowel transplant, some people will die within a few years of the procedure. However, the majority of adults and children who have the operation will live for at least another five years.
What is rejection?
Rejection is a normal reaction of the body. When a new organ is transplanted, your body’s immune system sees it as a threat and makes antibodies, which can stop it from working properly.
This is also known as graft versus host disease (GvHD), and it can occur within a few weeks of a transplant or, less commonly, a few months or even years later.
Immunosuppressant medications that weaken your immune system are given during and after your transplant and must be taken for life, to reduce the risk of your body rejecting your new bowel.
As well as stopping the donated organ working properly, rejection can sometimes mean that bacteria found in the small bowel can get into your bloodstream and cause a serious widespread infection. You will be closely monitored by the transplant team after surgery to reduce this risk.
In some cases where the transplant fails, you may be put on the waiting again for another transplant.
Small bowel transplant