Portal de Periódicos da CAPES

Short Bowel Syndrome/Intestinal Failure

2013; Elsevier BV; Volume: 163; Issue: 5 Linguagem: Inglês

10.1016/j.jpeds.2013.07.019

1097-6833

Jorge H. Vargas,

Infant Nutrition and Health

See related article, p 1361Intestinal failure is defined by the inability to maintain growth and development by regular means of nutrition. The causes vary, but the most common is short bowel syndrome, as a result of resection of necrotic bowel in the context of complications of prematurity, or the expression of congenital and developmental anomalies of the gastrointestinal tract. Until the development of techniques such as parenteral nutritional support, this diagnosis was fatal, or the prognosis and the outcomes of all these patients were very poor. See related article, p 1361 Once we were able to find an alternate way to supply these patients with calories and nutrients, the prognosis dramatically changed but was accompanied by an abundance of complications and side effects from the infusion of alimentary products via the intravenous route, which caused a major toll on patient outcomes. In this issue of The Journal, Infantino et al1Infantino B. Mercer D.F. Hobson B.D. Fisher R.T. Gerhardt B.K. Grant W.J. et al.Successes with the rehabilitation of pediatric ultrashort small bowel syndrome.J Pediatr. 2013; 163: 1361-1366Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar present the current perspective on a large group of patients with the most severe form of short bowel syndrome, the so-called “ultra-short small bowel” category. Their reported experience is quite encouraging and positive. We have had the opportunity to observe the developments in the care of the pediatric patient with intestinal failure, including the use of total parenteral nutrition, advances in surgical techniques and in organ transplantation, along with the development and discovery of different modalities and combination of nutrients to prevent complications. Therefore, it is rewarding to see how a systematic, careful, multidisciplinary, and particularly well-monitored management of these patients can produce such a positive result, namely intestinal adaptation and the ability to regain nutritional autonomy by the majority of these patients, obviating the need of intravenous supplementation. The main goals in the management of these patients include: (1) promotion of growth and development; (2) administration of a balanced and adequate diet; (3) maintenance of a good fluid and electrolyte balance; (4) prevention of infections; (5) prevention of liver disease; and (6) promotion of an optimal quality of life. For the first 2 goals, the reported lessons and collected experience suggest the demonstration of adequate calories and balanced nutrients while avoiding excessive support, cycling the intravenous solutions, and starting the oral route as soon as allowed by the postoperative course as well as maximizing the enteral route without causing excessive osmotic losses as important. We have also learned that caloric needs may be unique to individuals and that the assessment of energy expenditure may be helpful in preventing the complications of overfeeding that also may interfere with motor development in the developing infant. Regarding the third goal, consideration of the multifactorial causes of malabsorption in short bowel syndrome, including acid hypersecretion, rapid intestinal transit, loss of surface area, quality or impairment of the residual bowel, the presence of bacterial overgrowth, and bile-acid wasting, is helpful in complementing the choice of therapies or therapeutic agents. Specific pharmacologic therapies for the management of short bowel syndrome are mainly aimed at reducing gastric secretion and decreasing diarrhea both by decreasing a possible secretory component and by increasing segmental contractions of the bowel to decrease transit time. Reduction of diarrhea and water and electrolyte losses also includes the control of bacterial overgrowth with the use of antibiotics and perhaps pre- and probiotics. Manipulation of the intestinal flora in short gut may also be used to prevent reabsorption of oxalate from the colon with the prevention of renal stones and a less clear objective, such as the prevention of bacterial translocation and reduced intravenous catheter-associated infections.2Goulet O. Joly F. Intestinal microbiota in short bowel syndrome [in French].Gastroenterol Clin Biol. 2010; 34: S37-S43Crossref PubMed Scopus (26) Google Scholar The use of promotility agents that increase the segmental contractions, thus reducing transit time, like opiates, diphenoxylate, or loperamide and, in certain clinical settings, the use of long-acting forms of somatostatin (octreotide), are useful in preventing excessive losses. Hypergastrinemia as a result of increased stimulation by the infusion of amino acids and decreased catabolism of this hormone in short gut, with the subsequent increase in its half life, leads to gastric hypersecretion, which in turn reduces the coefficient of absorption of fats by decreasing mycelar formation and neutralizing pancreatic enzymes.3Kocoshis S. Medical management of pediatric intestinal failure.Semin Pediatr Surg. 2010; 19: 20-26Abstract Full Text Full Text PDF PubMed Scopus (66) Google Scholar In the past, several trials in which the investigators used growth factor (insulin-like growth factor-1) or growth hormone directly (somatotropin) were focused on the goal of accelerating intestinal growth; supplementation with glutamine to provide optimal intestinal physiology also was used with no objective positive results. Recently, the use of an analog to a naturally occurring gastrointestinal hormone (glucagon-like peptide-2-2) has emerged but has not been used in children. This agent is known to play a role in promoting adaptation by increasing villous height and crypt depth and by altering enterocyte turnover, thus increasing absorptive surface. The surgical options for therapy have evolved and have had a major impact on adaptation. Such approaches range from the simple establishment of continuity of the bowel, when multiple atretic segments occur or when the bowel has been divided because of major discrepancies in diameter, to re-establishment of continuity between the small and large bowel to optimize absorption of water and electrolytes as well as other nutritional factors, such as short-chain fatty acids, particularly if the ileo-cecal valve is present and intact. Other types of autologous reconstruction aimed at decreasing the velocity or rapidity of the intestinal transit by either creating “valves” by intussuscepting segments of bowel or by trying to reverse the peristalsis by interposing segments of retro-peristaltic colon were found to be nonefficacious and have been abandoned. Other procedures aimed at decreasing the dilation of the small intestine, either by longitudinally resecting a portion of the antimesenteric side of the dilated small bowel or by imbricating the bowel to reduce its diameter, have been performed at many institutions and proclaimed to be efficacious. Other types of surgical techniques, some quite ingenious but perhaps based on our simplistic mechanical view or belief in the concept that longer length facilitates better absorption, have led to the development of procedures determined to lengthen the bowel. In the Bianchi procedure, the intestine is divided longitudinally along the mesenteric axis, preserving the vasculature, creating two lumens with use of a stapler and then suturing pieces in continuity thus doubling the length of the segment. More recently, a procedure involving a series of transverse incision (serial transverse enteroplasty) with a stapler decreased the width (and the surface) but increased the length of the dilated bowel while destroying at least some of the vasculature and normal circulation, the anatomical array of the longitudinal and circular muscle layers, and the arrangement of the intrinsic nervous system, rendering the segment nonmotile. All these techniques have had variable and sometimes opposite results in different studies, and some of the small series presented as favorable are difficult to analyze; adaptation probably was already on the way or achieved and a thorough and critical analysis of the results has not taken place. The growth variables in these studies, the amount of stool output, as well as the claim for “adaptation” achieved is vague to modest at best. In our experience, with a few cases surgically managed in our institution and the majority in which surgery was performed elsewhere in patients referred subsequently for transplantation, poor results were usually observed, particularly among those with ultra-short bowel and/or those with remaining bowel that already may have had marginal motility, because of dilation, ischemia, severe wall thickening, or because of being very adherent.4Bueno J. Gutierrez J. Mazariegos G.V. Abu-Elmagd K. Madariaga J. Ohwada S. et al.Analysis of patients with longitudinal Intestinal lengthening procedures, referred for intestinal transplantation.J Pediatr Surg. 2001; 36: 178-183Abstract Full Text Full Text PDF PubMed Scopus (50) Google Scholar, 5Barksdale E.M. Stanford A. The surgical management of short bowel syndrome.Curr Gastroenterol Rep. 2002; 4: 229-237Crossref PubMed Scopus (28) Google Scholar, 6Ba'ath M.E. Almond S. King B. Bianchi A. Khalil B.A. Morabito A. Short bowel syndrome: a practical pathway leading to successful enteral autonomy.World J Surg. 2012; 36: 1044-1048Crossref PubMed Scopus (23) Google Scholar, 7Almond S.L. Haveliwala Z. Khalil B. Morabito A. Autologous intestinal reconstructive surgery to reduce bowel dilatation improves intestinal adaptation in children with short bowel syndrome.J Pediatr Gastroenterol Nutr. 2013; 56: 631-634Crossref PubMed Scopus (25) Google Scholar, 8Khalil B.A. Ba'ath M.E. Aziz A. Forsyth L. Gozzini S. Murphy F. et al.Intestinal rehabilitation and bowel reconstructive surgery: improved outcomes in children with short bowel syndrome.J Pediatr Gastroenterol Nutr. 2012; 54: 505-509Crossref PubMed Scopus (77) Google Scholar One aspect usually not found or addressed in the current literature on this subject is the descriptive pathology of segments that have undergone previous revisions or lengthening because often they are found to be narrowed, contracted, and scarred (sometimes replaced by prominent fibrous tissue with subsequent narrowing and further dilation of the proximal intestine) at the time of transplantation, usually undertaken because the patient has failed to adapt. In the current series, patients who had undergone lengthening procedures more frequently were in the group who failed to adapt. This consideration is important in patients with ultra-short small bowel. The small number of patients in the current series, as stated by the authors, decreases the statistical power, but it is interesting to note that the surgeons describe dilations of the bowel proximal or distal to even the portion upon which the procedure was performed, suggesting that the consequence on transit in that area of intestine is in practical terms obstructive. Another recent addition to surgical therapies has been organ transplantation; different types of grafts and surgical techniques have been developed, including liver transplant, the use of an isolated segment of small bowel, or the use of several organs including liver, pancreas, and even segments of colon. For intestinal grafts, the results are not encouraging to date, even with major advances in the field of immunosuppressant agents and medications, which have improved the short term or first-year survival rates of patients and grafts, although not affecting a fairly mediocre long-term graft survival rate. It seems that the bowel, because it is the largest immunologically active organ, is also the most difficult to “tame” with immunosuppressive medications. It requires not only larger doses or greater levels of some commonly used agents but also a combination of several drugs simultaneously, which often leads to infectious complications as well as a high incidence of lymphoproliferative disorders, and still not producing normal growth or nutritional independence and autonomy. The decision to offer only transplantation of the liver in the case of severe liver failure, specifically in patients with short gut syndromes, remains difficult and controversial because the rate of graft failure is greater for transplantation performed for other indications of end-stage liver disease; the determining factor may indeed be the lack of good graft perfusion in the case of short bowel syndrome. The main indications for transplantation continue to be the presence of severe liver disease and the lack of vascular access. Our understanding of what is now called parenteral nutrition−associated (ie, intestinal failure−associated) liver disease has evolved and importantly has linked the frequency and type of infections of central venous catheters, certain types of metabolic imbalances in the diets provided, the administration of “large” amounts of calories as fat, certain types of fatty acids, and the presence of deleterious chemicals in the lipid emulsions exclusively derived from soy or soy based products. The reduced or limited use of these types of emulsions and/or the substitution of fats with fish-oil derived, omega 3 fatty acids, has proven to be efficacious in preventing as well as reversing cholestasis and inflammation. The use of enteral omega-3 fatty acids has had a beneficial effect as well. Larger trials in this country are still underway, but already there seems to be substantial evidence of clear benefit of this therapy.9de Meiser V.E. Gura K.M. Meisel J.A. Pudor M. Fish oil-based lipid emulsion prevents and reverses parenteral nutrition associated liver disease: the Boston experience.JPEN J Parenter Enteral Nutr. 2009; 33: 541-547Crossref PubMed Scopus (150) Google Scholar, 10Rollins M.D. Scaife E.R. Jackson W.D. Meyers R.L. Mulrov C.W. Books L.S. et al.Elimination of soybean lipid emulsion in parenteral nutrition and supplementation with enteral fish oil improve cholestasis in infants with short bowel syndrome.Nutr Clin Pract. 2010; 25: 199-204Crossref PubMed Scopus (55) Google Scholar, 11Goulet O. Antebi H. Wolf C. Talbotec C. Alcindor L.G. Corriol O. et al.A new intravenous fat emulsion containing soybean oil, medium-chain triglycerides, olive oil and fish oil: a single center, double blind randomized study on efficacy and safety in pediatric patients receiving home parenteral nutrition.JPEN J Parenter Enteral Nutr. 2010; 34: 485-495Crossref PubMed Scopus (192) Google Scholar, 12Nehra D. Fallon E.M. Puder M. The prevention and treatment of intestinal failure-associated liver disease in neonates and children.Surg Clin North Am. 2011; 91: 543-563Abstract Full Text Full Text PDF PubMed Scopus (36) Google Scholar One aspect that still is unclear in this population of patients, more apparent in those with necrotizing enterocolitis or mid-gut volvulus, is the impact of an acute ischemic insult to the liver. Theoretically, this also applies to those patients with developmental anomalies, during intrauterine vascular accidents at different but early stages of intestinal development that compromise the venous return of the intestine, mesenteric, and thus, portal. Even potential infectious or chemical agents may have caused atresia of segments, which in turn compromises the portal flow or may have caused inflammation of the liver. This is suggested by the presence of markers of liver dysfunction and specifically hepatocellular necrosis in some infants before intravenous nutrition is administered. Another area of major impact on the prevention of liver disease is the prevention of catheter-associated infections, particularly those due to gram-negative bacteria. A team approach to educating parents and caregivers in the proper use of catheters, the administration of the solutions, and general care of the stomas and tube sites is critical. In general, catheter-associated infections more commonly are the result of contamination rather than bacterial translocation from the intestine. Aggressive treatment and prevention of potential infections by the use of ethanol- or antibiotic-containing locks to cap the central venous catheters are important considerations. In our experience, however, the main factor in prevention has been maintaining a consistent and strict protocol for catheter care, coupled with extensive and ongoing education of parents and caregivers (Wozniak et al, unpublisted data, 2013). The systematic treatment of bacterial overgrowth in these patients has not been proved to have a definite impact on reduction of infections, but it seems to have positive results in the improvement of tolerance of feedings as well as decreasing volume of diarrhea. Much is yet to be learned about the macrobiota of these patients to establish clear variables of therapy and therapeutic agents for this specific purpose.2Goulet O. Joly F. Intestinal microbiota in short bowel syndrome [in French].Gastroenterol Clin Biol. 2010; 34: S37-S43Crossref PubMed Scopus (26) Google Scholar Enteral administration of urso-deoxycholic acid for the prevention of liver disease is promising, but there is limited knowledge of the kinetics of the medication in children, its ability to be absorbed in the different categories or “topography” of remaining bowel, and whether the effect of the medication depends on its absorption. It is unclear whether use of urso-deoxycholic acid, besides perhaps helping maximize enteral feedings, changes the volume of diarrhea, changes composition of bile, improves biliary flow, and prevents or decreases cholestasis and thus cholelithiasis. In general the evidence base for medical and nutritional interventions in the context of intestinal failure in children is limited. The major lesson of the current series is that potentially better outcomes for these patients depend on early intervention and referral to the multidisciplinary intestinal failure center. Benefits include enhanced survival rate, improved overall quality of life, and the capacity to achieve adaptation and become independent of the IV calories. Cooperation and communication among these larger centers hopefully will bring improvement in evidence-based management, through larger and better cohort and case-control research. Successful Rehabilitation in Pediatric Ultrashort Small Bowel SyndromeThe Journal of PediatricsVol. 163Issue 5PreviewTo examine treatment outcomes in pediatric patients with ultrashort small bowel (USSB) syndrome in an intestinal rehabilitation program (IRP). Full-Text PDF