Transplantation

Intestinal Transplantation

Mr Darius F Mirza, Consultant Transplant and Hepatobiliary Surgeon

What is intestinal failure?

Intestinal failure may develop when a person’s bowel function does not provide the necessary long term nutrition required to sustain a normal life. This leads to the need for long term additional nutrition delivered via large veins in the body. When a person receives his/her entire caloric intake via the intravenous route, the situation is described as being on “total parenteral nutrition” (TPN). In the UK, most patients on TPN receive this at home, and they lead reasonably normal lives. Some of these patients develop complications related to TPN.

The wider practice of intestinal or small bowel transplantation is a relatively recent development in the UK, and is an established treatment option in selected patients with intestinal failure. Proportionately, intestinal failure occurs more frequently in children compared to adults. There are broadly two types of conditions that may lead to intestinal failure

1) short gut (shortened small intestine to less than around 40 cm in length) due to a variety of causes – eg: birth defects such as intestinal atresia and gastroschisis; bowel loss after vascular occlusion (thromboses); extensive bowel resections due inflammatory diseases such as Crohn’s disease or after some rare tumours of the bowel.

2) non functioning bowel – disorders of the inner lining (mucosa) like microvillous inclusion disease, motility disorders like pseudo-obstruction, and total aganglionosis of the bowel.

How is intestinal failure managed?

The standard treatment for patients with intestinal failure is intravenous nutrition, also referred to a parenteral or total parenteral nutrition. This is usually delivered at home and most of these patients lead reasonably normal lives despite not being able to eat. Approximately 20%-40% of children and a smaller number of adults on intravenous nutrition develop life threatening complications related to long term parenteral nutrition. These include recurrent infections of the intravenous feeding line, thrombosis/blockage of major blood vessels resulting in shortage of access to the bloodstream to deliver this nutrition, and intestinal failure associated liver disease (IFALD). These sick small bowel failure patients are best managed by a multidisciplinary team of surgeons, physicians, anaesthetists, nurses, dieticians and co-ordinators specialising in intestinal failure and working closely with intestinal transplant teams.

What is intestinal transplantation and where is it available in the UK?

In some patients, intestinal transplantation is a life saving option. Patients with associated irreversible IFALD will require combined liver and bowel transplantation. As of summer 2009, over 2200 intestinal transplants have been performed worldwide in 73 small bowel transplant centres. Approximately 80% of the world’s bowel transplants have been performed at 12 high volume centres in the world, where better outcomes after this complex procedure have been achieved. In the UK, intestinal transplantation was first performed in adults at Addenbrooke’s Hospital, Cambridge in 1987 and in children at the Children’s Hospital in Birmingham in 1993. As of September 2009, a total of 91 intestinal transplants have been performed, 67 in Birmingham, 16 at Cambridge 5 in Oxford and 3 at Kings College Hospital, London.

There are currently four designated centres for intestine transplantation in the UK:

Birmingham: Children’s Hospital
Cambridge: Addenbrooke’s Hospital
London: King’s College Hospital
Oxford: John Radcliffe Hospital

Which patients are suitable for intestinal transplantation?

In patients with complications of intestinal failure, the following criteria require to be established before a patient may be considered for intestinal transplantation:

The presence of irreversible intestinal failure

and one or more of the following

• impaired venous access (reduced to the last two suitable veins for placement of the feeding catheter)

• progressive liver disease

• life threatening episodes of catheter related sepsis

What are the different types of intestinal transplants?

Depending on the clinical situation a patient may be considered for one of several different forms of intestine transplants. This depends on the presence or absence of liver disease, the ability of the patients’ stomach to empty correctly and also on the amount of functional native bowel still available.

1) Isolated bowel transplant

2) full size liver bowel pancreas multivisceral transplant

3) reduced size liver bowel pancreas multivisceral transplant

4) multivisceral transplant with liver, stomach, bowel, pancreas

5) reduced size multivisceral transplant with liver, stomach, bowel, pancreas

6) modified multivisceral transplant with stomach, pancreas, bowel

7) liver alone (if there is irreversible liver disease but reversible bowel disease)

Isolated Bowel Transplant

Combined Liver Bowel Pancreas (Multivisceral) Transplant

Reduced Size Liver Bowel Pancreas (Multivisceral) Transplant

Outcomes after intestine transplantation:

The results of bowel transplantation continue to improve but remain somewhat inferior to other common organ transplants such as liver or kidney transplantation. The recovery time is also significantly longer after intestine transplantation. All patients receive an artificial opening of the bowel onto the abdominal wall called a stoma. This allows the transplant team to assess how the transplanted bowel is functioning and allows easy access for biopsies and also for endoscopic examination of the transplanted bowel. Sometimes the patients’ abdomen cannot be closed immediately and it may take several days to achieve closure. During this time the patient remains on the intensive care unit.

The levels of immunosuppression medicines required after intestinal transplantation is greater than prescribed for other transplants. Acute rejection is commonly seen after transplantation and requires additional treatment with immunosuppression medication, usually with big doses of corticosteroids. Approximately two thirds of patients make a long term recovery and around 90% of these patients are off intravenous feeding. A small proportion of patients develop late rejection several months or years after transplantation and sometimes the bowel transplant needs to be removed. Some of these patients may be considered for a second transplant.

Intestine transplant patients are also more prone to develop some additional complications including opportunistic viral infections, graft versus host disease, post transplant lymphoproliferative disease and rare forms of haemolytic anaemia.