Some persons are born with or develop irreversible intestinal failure. Intestinal failure occurs when a person's intestines can't digest food and absorb the fluids, electrolytes and nutrients essential to life and normal development. Patients must then receive TPN, which provides liquid nutrition through a catheter or needle inserted into a vein in the arm, groin, neck or chest.
Total Parenteral Nutrition (TPN)
Patients with intestinal failure may receive all or most of their nutrients and calories intravenously through total parenteral nutrition, or TPN. TPN is given through a catheter placed in the arm, groin, neck or chest. Patients on TPN may live for many years, but long-term use of TPN can result in serious complications, such as bone disorders, central venous catheter infections and liver disease. If those complications become life-threatening, an intestinal transplant may be required.
Causes of Intestinal Failure
The most common cause of intestinal failure is short bowel syndrome where at least half or more of the small intestine has been removed. Short bowel syndrome is typically a postsurgical condition for treatment of conditions such as trauma or necrotizing enterocolitis.
Pedatric vs. Adult Causes
Intestinal failure may also be caused by functional disorders such as Crohn's disease, a digestive disorder, or chronic idiopathic intestinal pseudo-obstruction syndrome. The conditions leading to intestinal failure are age-dependent. That is, some conditions are more closely associated with pediatric intestinal failure while others are more common with intestinal failure in adults.
Pediatric Conditions Causing Intestinal Failure
- Congenital malformations such as small bowel atresia, gastroschisis, aganglionosis
- Infections of the gastrointestinal tract such as necrotizing enterocolitis)
- Short bowel syndrome following extensive bowel surgeries secondary to mesenteric ischemia (e.g., midgut volvulus)
- Absorptive impairment (e.g., intestinal pseudo-obstruction, microvillus inclusion disease)
Adult Conditions Causing Intestinal Failure
- Short bowel syndrome following extensive surgeries secondary to mesenteric ischemia (following thrombosis, embolism, volvulus, or trauma)
- Inflammatory bowel disease such as Crohn's disease
- Small bowel tumors such as Gardner's syndrome (familial colorectal polyposis)
- Tumors of the mesenteric root and retroperitoneum (desmoid tumor)
Intestinal Failure and Transplantation
An intestinal transplant is a last-resort treatment option for patients with intestinal failure who develop life-threatening complications from total parenteral nutrition (TPN). Long-term TPN can result in complications including bone disorders, catheter-related infections and liver failure. Over an extended period of time, TPN also can damage veins used to administer the nutrition via the catheter.
An Intestinal transplant is a complex procedure requiring a highly skilled multidisciplinary transplant team. An isolated Intestinal transplant surgery takes approximately three to four hours to complete whereas a multivisceral (multi-organ) transplant operation can take up to twelve hours.
There are three major types of intestinal transplants:
Isolated intestinal (Small Bowel) Transplantation
In an isolated intestinal transplant, the diseased portion of the small intestine is removed and replaced with a healthy small intestine from a donor. In an isolated intestinal transplant, the disease limited to the small bowel only without liver failure. This procedure can be lifesaving for patients with irreversible intestinal failure that has become life-threatening.
Combined Liver and Intestinal Transplantation
Combined liver and intestine transplantation is done for patients with both liver and intestinal failure. IN In this procedure, the diseased liver and intestine are removed and replaced with a healthy liver and intestine from an organ donor. Complications of intravenous nutrition (TPN) are the main cause of liver failure attendant to intestinal failure. Without a transplant, patients with intestinal and liver failure have an expected median survival of 6 - 12 months while continued on TPN.
Multivisceral transplantation is performed where two or more intra-abdominal organs (including the intestines) are failing. The transplanted organs may include the stomach, duodenum, pancreas, intestine, and liver. This complex procedure can be life-saving for patients with combined abdominal organ failure resulting diseases such as Gardner's syndrome (familial colorectal polyposis), a pre-malignant colorectal condition and intestinal pseudo-obstruction (decreased ability of the intestines to push food through).
Evaluation for Intestinal Transplantation
During the evaluation process, a detailed medical history is taken and numerous studies (tests) are performed to determine whether an intestinal transplant is likely to benefit the patient including:
- Abdominal CT scan
- Barium enema
- Blood tests for liver function, electrolytes, kidney function and antibodies to certain viruses
- ECG and echocardiogram
- Motility studies
- Ultrasound of the circulatory system
- Upper gastrointestinal and small bowel X-ray series
Intestinal Transplant Procedure
In an Intestinal transplant, the small intestine (small bowel) is surgically removed (along with any other diseased organs such as the liver), and replaced with healthy organ(s). Initially, the blood vessels of the patient and donor are connected to establish a blood supply to the transplanted intestine. The donor's intestine is then connected to the patient's gastrointestinal tract.
An ileostomy is then performed. An ileostomy is a surgically created opening through which the ileum, a section of the patient's small intestine, is brought up through the abdominal wall. This opening allows body waste to pass directly out of the body and empty into a pouch. The ileostomy also allows the transplant team to assess the health of the patient's transplanted intestine. In time, most patients are able to have the ileostomy closed. A feeding tube is also placed into the stomach to help the patient transition to an oral diet.