Update on the management of intestinal failure
ABSTRACTIntestinal failure is a serious complication of conditions such as inflammatory bowel disease, mesenteric ischemia, and radiation enteritis—and of extensive bowel resection performed because of these diseases. Imbalances of fluids and electrolytes and poor nutritional status manifest as chronic diarrhea or increased ostomy output. Prompt referral to a center specializing in intestinal rehabilitation is key to achieving nutritional homeostasis and, in some cases, can help the patient return to oral food intake. We review the intestinal sequelae of bowel resection and provide an update on intestinal rehabilitation with dietary modification, drug therapy, and parenteral nutrition. We also review current experience with intestinal transplant, a potentially lifesaving option in select patients when intestinal rehabilitation fails or parenteral nutrition causes severe complications.
KEY POINTS
- Some patients with intestinal failure require lifelong parenteral nutrition, which increases the risk of complications such as infection and liver disease. For these patients, intestinal transplant has emerged as a therapeutic option toward the goal of restoring nutritional autonomy.
- The complexities of intestinal failure require collaboration of multiple specialists—gastroenterologists, surgeons, dietitians, nurses, psychiatrists or psychologists, pharmacists, and social workers. This multidisciplinary team is essential to intestinal rehabilitation.
- Dietary modification is the single most effective means of weaning patients safely from parenteral nutrition.
DRUG THERAPY
In addition to diet therapy, most patients with intestinal failure require pharmacologic therapy.28 High stool or stoma effluent is most commonly treated with an antidiarrheal to increase transit time; diphenoxylate-atropine, loperamide, codeine sulfate, paregoric, and opium tincture are commonly prescribed (Table 5).27 In severe high-output states, a somatostatin analogue (eg, octreotide) may be added.29
Postoperative increases in gastric secretion may be countered by histamine 2 receptor antagonists and proton pump inhibitors, but long-term use of these drugs may lead to nutritional deficiencies and bacterial overgrowth in the small intestine.29 Bile acid sequestrants (in cases of distal ileal resection) and pancreatic enzymes target fat malabsorption, resultant cases of choleretic diarrhea, deficiency of essential fatty acids, kidney stones, and deficiency of fat-soluble vitamins.29 Probiotics and antibiotics can also be given for prevention and treatment of small-intestinal bacterial overgrowth.29
When traditional dietary modification and medical therapy fail to achieve nutritional homeostasis, another option to consider is a glucagon-like peptide-2 analogue to enhance intestinal adaptation.30 Produced in the native distal ileum and colon, glucagon-like peptide 2 moderates the rate of gastric emptying and small-bowel transit and enhances epithelial cell proliferation, thereby promoting intestinal adaptation.30 Further, a randomized controlled trial of 83 patients reported efficacy of these agents in reducing parenteral nutrition requirements in patients with intestinal failure.31
Hence, in patients with intestinal failure who have increased stoma effluent, drug therapy may play an important role in maintaining fluid and nutritional homeostasis.
THE ROLE OF PARENTERAL NUTRITION IN INTESTINAL FAILURE
Despite the best efforts of an intestinal rehabilitation program, not all patients gain nutritional autonomy.32 Physiologic, psychological, social, and economic factors may contribute to dependence on parenteral nutrition.32 Currently, more than 40,000 US patients depend on it for survival.33
The need for short-term or long-term parenteral nutrition is determined by the patient’s medical needs.33 Patients requiring short-term parenteral nutrition (2–6 weeks) include those whose bowel function has not returned to normal postoperatively, and those who were severely malnourished preoperatively.34 Patients needing it long-term (from months to years to lifelong) are those with gastrointestinal dysmotility and short-bowel syndrome due to extensive bowel resections.33
Complications of parenteral nutrition
Catheter-related bloodstream infection is the most common complication and cause of hospitalization. Infection can be localized to the exit site or tunnel or can be systemic (eg, line sepsis).35Staphylococcus aureus and coagulase-negative staphylococci are most often implicated in catheter infection.35 When possible, catheter salvage is desirable, but the central venous catheter must be removed in cases of tunnel infection, port abscess, septic shock, paired blood cultures positive for fungi or highly virulent bacteria, endocarditis, septic thrombosis, and other conditions.35,36
Liver disease is a serious complication of long-term parenteral nutrition and may occur in up to 55% of patients on therapy for more than 2 years; it carries a mortality rate of 15%.37
Risk factors include younger age and use of excessive carbohydrate and fat compositions, mainly soybean-oil–based lipid emulsions.37 However, fish-oil–based lipid emulsions have recently shown promise in preventing and reversing parenteral nutrition-associated liver failure and cholestasis, especially in a pediatric population.38
Catheter thrombosis may occur in up to 30% of patients on long-term parenteral nutrition.39 However, this risk is reduced with appropriate positioning of the catheter tip in the mid or lower superior vena cava.37 Treatment of thrombosis of the central access includes either anticoagulation or thrombolysis.37
Hence, appropriate and timely follow-up of patients on parenteral nutrition is essential in reducing associated complications. Monitoring weight, fluid status, serum glucose, and patency of central access are critical to ensure that the patient maintains nutritional status effectively.40 To prevent complications, a specialized nutritional support team should monitor the patient’s parenteral nutrition both in the hospital and at home.
RECONSTRUCTIVE SURGERY
Patients with intestinal failure due to short- bowel syndrome should be considered for reconstructive surgery during different phases of the adaptation process. Options include reversed-segment procedures, stricturoplasty, bowel-lengthening procedures (eg, the Bianchi procedure), and serial transverse enteroplasty.41,42 If reconstructive surgery is ineffective, referral to an intestinal transplant program should be considered.
INTESTINAL AND MULTIVISCERAL TRANSPLANT
For patients who develop permanent intestinal failure and require lifelong parenteral nutrition, and for patients who experience significant complications of parenteral nutrition, such as infections and liver disease,43 intestinal transplant has emerged as a way to restore clinical nutritional autonomy.44 In one study, the 1-year survival rate after intestinal transplant was approximately 90%.44
There are currently three transplant procedures: isolated intestine transplant, combined liver-intestine transplant, and multivisceral transplant with or without a liver, depending on the presence of parenteral nutrition-associated liver disease.42,45 Close postoperative care is required to help the patient transition from parenteral to enteral nutrition.42 An intestinal rehabilitation team is equipped to provide this level of postoperative care.42
Intestinal and multivisceral transplant gained momentum in the early 1960s in preclinical and clinical studies.46,47 Since that time, the field has experienced remarkable advances due to standardization of surgical techniques, novel immunosuppressive therapies and induction protocols, and improved postoperative care.48 With the advent of tacrolimus in 1989, the rates of allograft rejection improved significantly, and the field of transplant emerged as a potentially lifesaving therapy for patients with permanent intestinal failure.48
Since 1990, more than 2,300 intestinal transplant procedures have been performed for various etiologies of intestinal failure, with short-bowel syndrome being the most common.49
The indications for intestinal transplant approved by the US Centers for Medicare and Medicaid services are detailed in Table 6.50 Despite ongoing challenges of graft rejection and maintenance immunosuppression, posttransplant quality-of-life questionnaires have indicated a significant improvement in functional status and a decrease in depressive symptoms.51 As such, it is evident that intestinal and multivisceral transplant offers substantial promise in restoring a patient’s quality of life and nutritional status.
