Clinical Pearls & Morning Reports
Published August 16, 2017
Intestinal failure has been defined as “the reduction of functional gut mass below the minimal amount necessary for digestion and absorption adequate to satisfy the nutrient and fluid requirements for maintenance in adults or growth in children.” An umbrella label, intestinal failure includes the surgical short-bowel syndrome (intestinal resection for acquired or congenital gastrointestinal diseases, leading to clinically significant malabsorption and requiring specialized nutritional therapy), as well as disorders of gastrointestinal motility (e.g., intestinal pseudo-obstruction) and congenital enterocyte disorders (microvillus inclusion disease, tufting enteropathy, and others). A New England Journal of Medicine article reviews the natural history and management of pediatric intestinal failure due to the surgical short-bowel syndrome. Read the latest Review Article.
Q. How does the intestine adapt to massive post-surgical bowel loss?
A. The process of intestinal adaptation to massive bowel loss has been described as a compensatory process wherein the remaining bowel undergoes substantial structural and functional changes that increase its absorptive capacity. Histologic hallmarks of the compensatory process include increased villous height and crypt depth, with gross anatomical features that include bowel lengthening and dilatation. Such adaptation is promoted by a combination of mechanical, humoral, and luminal factors, and putative molecular signaling pathways are being actively investigated. It is thought that aggressive enteral therapy enhances adaptation and prevents complications associated with prolonged parenteral therapy.
Q. What complications are associated with parenteral nutrition?
A. Meticulously administered fluid, electrolyte, and nutritional therapy, with both specialized parenteral and enteral nutrition, is the mainstay of treatment for pediatric intestinal failure. Prolonged parenteral nutrition is lifesaving but nevertheless may lead to numerous complications, including central catheter–associated bloodstream infections, mechanical catheter–associated complications (breakage or thrombosis), metabolic bone disease, and intestinal failure–associated liver disease.
A: Newer intravenous fat emulsions, one containing a four-lipid combination of soy, olive, fish, and medium-chain oils and the other containing olive and soy oils were approved for use in adults by the Food and Drug Administration in 2016 and 2013, respectively. The four-lipid product has undergone preliminary evaluation in infants with early intestinal failure–associated liver disease (mean direct bilirubin level, 1 to 3 mg per deciliter [17 to 50 μmol per liter]). In a multicenter pilot study (a blinded, randomized, controlled trial comparing the four-lipid product with a soy-based lipid emulsion), the conjugated bilirubin level was significantly lower in 11 infants who received the four-lipid product than in 13 infants treated with the soy-based lipid emulsion, each for a mean duration of 8 weeks. Therapy with gastrointestinal hormones to induce intestinal adaptation shows promise as a medical therapy for intestinal failure. Glucagon-like peptide 2 (GLP-2) is a naturally occurring hormone secreted by enteroendocrine cells in the distal ileum and colon. GLP-2 induces small-bowel epithelial proliferation and delays gastric emptying.
A: Autologous intestinal reconstruction surgery aims to taper and lengthen the remaining bowel in order to improve motility, enhance absorption, and limit bacterial overgrowth. The longitudinal intestinal lengthening and tailoring procedure (LILT), commonly referred to as the Bianchi operation, was first described in 1980. A simpler operation, serial transverse enteroplasty (STEP), was developed more recently. Data from the International STEP Registry indicate that among patients in whom standard bowel rehabilitation is not successful, 66% have improved enteral tolerance and 47% are fully weaned from parenteral nutrition after undergoing the initial STEP procedure. These two procedures have not been directly compared, although limited data appear to support the STEP procedure, which is less technically difficult than LILT and can be repeated. Some children with intestinal failure are candidates for intestinal or multivisceral transplantation. There are currently more than 1000 living intestinal-transplant recipients in the United States, nearly half of whom underwent transplantation as children.