Indications for specific therapy in the rehabilitation of patients with the short-bowel syndrome

Criteria for the Use of Recombinant Human Growth Hormone in Short Bowel Syndrome

Extensive resection of the intestinal tract with resulting malabsorption is known as short bowel syndrome (SBS). Adaptation and rehabilitation of the remaining small bowel occurs spontaneously after resection and can be enhanced by diet, medications, and use of intestinal trophic factors such as recombinant human growth hormone (r-hGH). Many trials have been published on the influence of r-hGH therapy in SBS patients, with varying results. Analysis of the trials has produced a set of criteria that can be used to define the patient most likely to benefit from r-hGH therapy.

Enteral approaches in malabsorption

Enteral autonomy and freedom from parenteral nutrition dependency is the ultimate therapeutic goal in children with intestinal failure. This can be achieved following attainment of bowel adaptation in conditions such as short bowel syndrome. Enteral nutrition is a major therapeutic cornerstone in the management of children with intestinal failure. It promotes physiological development, bowel adaptation and enhances weaning from parenteral nutrition. The optimal method of delivery, type of nutrients, timing of initiation, promotion of feeds and transition to solid food in children with short bowel syndrome are debated. Lack of high quality human data hampers evidence based conclusions and impacts daily practices in the field. Clinical approaches and therapeutic decisions are regularly influenced by expert opinion and center practices. This review summarizes the physiological principles, medical evidence and practice recommendations on enteral nutrition approaches in short bowel syndrome and provides a practical framework for daily treatment of this unique group of patients. Oral and tube feeding, bolus and continuous feeding, type of nutrients, formulas, trace elements and solid food options are reviewed. Future collaborative multicenter, high quality clinical trials are needed to support enteral nutrition approaches in intestinal failure.

Increased intestinal absorption by segmental reversal of the small bowel in adult patients with short-bowel syndrome: a case-control study

BACKGROUND

Segmental reversal of the small bowel (SRSB) is proposed in patients with short-bowel syndrome (SBS) as a rehabilitative therapy, but its effects on absorption have not been studied.

OBJECTIVE

We aimed to determine intestinal macronutrient absorption and home parenteral nutrition (HPN) dependence in SBS patients with intestinal failure.

DESIGN

We included in a retrospective study all consecutive patients who had an SRSB between 1985 and 2010 and underwent a study of macronutrient absorption. Patients were matched to SBS controls with the same digestive characteristics. Energy and macronutrient absorption were measured. The dependence on HPN was expressed by the number of infusions per week and by the calories infused daily divided by the basal energy expenditure multiplied by 1.5.

RESULTS

Seventeen patients who had an SRSB were matched to 17 control patients. Intestinal absorption was higher in the SRSB group for total calories (69.5% compared with 58.0%), fat (48.4% compared with 33.2%), and protein (62.7% compared with 53.4%) (P < 0.05). Median oral autonomy was 100% ± 38.4% in the SRSB group, whereas it was 79% ± 39.6% in the control group (P < 0.05). The number of calories infused was lower in the SRSB group (500 ± 283 compared with 684 ± 541; P < 0.05), as was HPN dependence (33% ± 20% compared with 48% ± 38%; P < 0.05) at the time of the study.

CONCLUSION

SRSB allows a gain in macronutrient absorption, which is associated with a lower HPN dependence. To our view, SRSB should be integrated in intestinal rehabilitative adult programs.

Growth hormone to improve short bowel syndrome intestinal autonomy: a pediatric randomized open-label clinical trial

BACKGROUND

The ability of growth hormone (GH) to promote the weaning-off of parenteral nutrition (PN) in short bowel syndrome (SBS) is unclear. No randomized controlled study is available in children. This study was undertaken to determine if GH could enhance the weaning off of PN in PN-dependent children with SBS.

METHODS

A prospective randomized open-label multicenter study was performed in 14 patients (mean age, 9 ± 1.4 years) with SBS (average small bowel length, 33 cm) and long-term PN dependency (8 years) on an unrestricted diet. A standardized PN decrease with and without GH (0.14 mg/kg/d) was conducted. The patients were randomized to either a GH group (4 months of GH) or a control (CTR) group (4 months without GH, followed by 4 months with GH). Blood tests and a nutrition assessment of enteral and parenteral intakes were performed. Groups were compared with the Wilcoxon test.

RESULTS

Treatment with GH did not improve the weaning off of PN (decrease in PN caloric intake of 32.5% ± 9.6% in the GH group vs 35.2% ± 8.7% in the CTR group, nonsignificant). In the CTR group, GH treatment induced an additional but not statistically significant decrease of 8.8% ± 12.4% in daily calories. Parenteral needs returned to near basal rates 6 months after GH discontinuation (GH: 77.6% ± 10.6% vs CTR: 73.2% ± 7.4%). Weight decreased slightly in both groups. No biological parameters varied significantly.

CONCLUSIONS

GH did not improve the weaning off of PN in PN-dependent children with SBS.

Severe metabolic alkalosis and recurrent acute on chronic kidney injury in a patient with Crohn's disease

Background

Diarrhea is common in patients with Crohn's disease and may be accompanied by acid base disorders, most commonly metabolic acidosis due to intestinal loss of bicarbonate.

Case Presentation

Here, we present a case of severe metabolic alkalosis in a young patient suffering from M. Crohn. The patient had undergone multiple resections of the intestine and suffered from chronic kidney disease. He was now referred to our clinic for recurrent acute kidney injury, the nature of which was pre-renal due to profound volume depletion. Renal failure was associated with marked hypochloremic metabolic alkalosis which only responded to high volume repletion and high dose blockade of gastric hypersecretion. Intestinal failure with stomal fluid losses of up to 5.7 litres per day required port implantation to commence parenteral nutrition. Fluid and electrolyte replacement rapidly improved renal function and acid base homeostasis.

Conclusions

This case highlights the important role of gastrointestinal function to maintain acid base status in patients with Crohn's disease.

Tube feeding improves intestinal absorption in short bowel syndrome patients

BACKGROUND & AIMS

Tube feeding, recommended for patients with short bowel syndrome in only the postoperative period, has not been compared with oral feeding for absorption. We studied whether tube feeding increased absorption in patients with short bowel syndrome following the postoperative period.

METHODS

A randomized crossover study compared absorption between isocaloric tube feeding and oral feeding in 15 short bowel syndrome patients more than 3 months after short bowel constitution. An oral feeding period combined with enriched (1000 kcal * day(-1)) tube feeding was also tested. We measured the net intestinal absorption rates of proteins, lipids, and total calories using elemental nitrogen, Van de Kamer, and bomb calorimetry methods, respectively.

RESULTS

Tube feeding increased the mean (+/-SD) percent absorption (P < .001) of proteins (72% +/- 13% vs 57% +/- 18%), lipids (69% +/- 25% vs 41% +/- 27%), and energy (82% +/- 12% vs 65% +/- 16%) compared with oral feeding. In the group given the combined feedings (n = 9), the total enteral intake and net percent absorption increased (P < .001) for proteins (67% +/- 10%), lipids (59% +/- 19%), and total energy (75% +/- 8%) compared with oral feeding. Absorption (kcal * day(-1)) was greater (P < .001) with tube (2225 +/- 457) and combined feedings (2323 +/- 491) than with oral feeding (1638 +/- 458).

CONCLUSIONS

In patients with short bowel syndrome, continuous tube feeding (exclusively or in conjunction with oral feeding) following the postoperative period significantly increased net absorption of lipids, proteins, and energy compared with oral feeding.

Very low birth weight preterm infants with surgical short bowel syndrome: incidence, morbidity and mortality, and growth outcomes at 18 to 22 months

OBJECTIVES

The objective of this study was to determine the (1) incidence of short bowel syndrome in very low birth weight (<1500 g) infants, (2) associated morbidity and mortality during initial hospitalization, and (3) impact on short-term growth and nutrition in extremely low birth weight (<1000 g) infants.

METHODS

Infants who were born from January 1, 2002, through June 30, 2005, and enrolled in the National Institute of Child Health and Human Development Neonatal Research Network were studied. Risk factors for developing short bowel syndrome as a result of partial bowel resection (surgical short bowel syndrome) and outcomes were evaluated for all neonates until hospital discharge, death, or 120 days. Extremely low birth weight survivors were further evaluated at 18 to 22 months' corrected age for feeding methods and growth.

RESULTS

The incidence of surgical short bowel syndrome in this cohort of 12316 very low birth weight infants was 0.7%. Necrotizing enterocolitis was the most common diagnosis associated with surgical short bowel syndrome. More very low birth weight infants with short bowel syndrome (20%) died during initial hospitalization than those without necrotizing enterocolitis or short bowel syndrome (12%) but fewer than the infants with surgical necrotizing enterocolitis without short bowel syndrome (53%). Among 5657 extremely low birth weight infants, the incidence of surgical short bowel syndrome was 1.1%. At 18 to 22 months, extremely low birth weight infants with short bowel syndrome were more likely to still require tube feeding (33%) and to have been rehospitalized (79%). Moreover, these infants had growth delay with shorter lengths and smaller head circumferences than infants without necrotizing enterocolitis or short bowel syndrome.

CONCLUSIONS

Short bowel syndrome is rare in neonates but has a high mortality rate. At 18 to 22 months' corrected age, extremely low birth weight infants with short bowel syndrome were more likely to have growth failure than infants without short bowel syndrome.

Short bowel syndrome

Treatment of short bowel syndrome (SBS) is often a difficult endeavor due to the high variability among patients with SBS in regard to remaining anatomical structure and functional capacity. Research efforts to substantiate the use of existing therapies in the treatment of SBS are ongoing, with newer developments yet to be fully explored. Current therapy for SBS begins with the implementation of a modified diet based on the presence or absence of the colon. Patients with difficulty ingesting enough nutrients and fluids for weight maintenance and fluid balance may benefit from nocturnal enteral nutrition and hydration. Those with inadequate absorptive capacity despite maximization of oral and enteral intake will need parenteral nutrition (PN) or hydration. Medications, including antisecretory agents, antidiarrheals, pancreatic enzymes, bile acid sequestrants, and antibiotics, often are useful in abating symptoms commonly associated with SBS. Growth factors, including recombinant human growth hormone and glucagon-like peptide 2, may be trialed to stimulate intestinal adaptation and enhance absorption in PN-dependent SBS patients. The gradual refinement of surgical procedures for SBS, including small bowel transplantation, has led to improved outcomes, and early referral of SBS patients to centers of excellence will optimize care.

Dietary supplementation with orotate and uracil increases adaptive growth of jejunal mucosa after massive small bowel resection in rats

BACKGROUND

Massive small-bowel resection (SBR) increases adaptive growth of residual intestine in animal models of short-bowel syndrome (SBS). Pyrimidine nucleotides are critical for DNA and RNA synthesis, but no previous study has evaluated whether supplementation of pyrimidines or their precursors in the diet enhances adaptive gut growth after SBR. This study determined growth responses in jejunal mucosa after 7 days of dietary supplementation with uracil, or its precursor, orotate, after massive SBR in rats.

METHODS

Sprague-Dawley rats ( approximately 200 g) underwent 80% jejunoileal resection (RX) or ileal transection (TX; control). Rats were pair-fed a purified (AIN-93G) powdered diet supplemented with or without 1% (wt/wt) orotate or uracil until killing at 7 days postsurgery. Defined jejunal segments were obtained for analysis of mucosal villus height (VH), crypt depth (CD), total mucosal height, bromodeoxyuridine (BrdU) incorporation, an index of cell proliferation, and full-thickness DNA and protein content as measures of intestinal adaptive growth.

RESULTS

Jejunal VH increased significantly with SBR, as expected, and orotate further stimulated this response. Jejunal CD and total mucosal height increased significantly with both orotate and uracil supplementation compared with resected animals receiving standard diet. Orotate administration also increased jejunal DNA content compared with the increase observed with SBR alone. Finally, orotate, but not uracil, supplementation increased BrdU incorporation compared with resected rats fed standard or uracil-supplemented diet after SBR.

CONCLUSIONS

Supplementation of oral diet with the pyrimidine precursor orotate and uracil stimulated adaptive jejunal growth after massive SBR in rats. Dietary orotate had more potent growth-stimulatory effects than uracil in this animal model. Dietary supplementation with orotate and uracil represents a novel nutrition approach to enhance small-bowel mucosal adaptive growth and absorptive capacity in SBS.

Mechanisms of enteral nutrient-enhanced intestinal adaptation

The role of enteral nutrients in maintaining small intestinal structure and function is well established. Evidence that enteral nutrients induce intestinal adaptation include the structural and functional gradient along the length of the healthy intestine, the atrophy and functional compromise induced by fasting and parenteral nutrition, and the enhanced adaptive capacity of the distal intestine following partial enterectomy. Key mechanisms contributing to enteral nutrient-induced intestinal adaptation include nonspecific luminal stimulation and that provided by specific nutrients, "functional workload" induced by polymeric nutrients, potential stimulation of pancreaticobiliary secretions, secretion of humoral mediators, and induction of intestinal hyperemia.

Causes and management of intestinal failure in children

Intestinal failure is a condition requiring the use of parenteral nutrition as long as it persists. Causes of severe protracted intestinal failure include short bowel syndrome, congenital diseases of enterocyte development, and severe motility disorders (total or subtotal aganglionosis or chronic intestinal pseudo-obstruction syndrome). Intestinal failure may be irreversible in some patients, thus requiring permanent parenteral nutrition. Liver disease may develop with subsequent end-stage liver cirrhosis in patients with intestinal failure as a consequence of both underlying digestive disease and unadapted parenteral nutrition. Death will occur if combined liver-intestine transplantation is not performed. Catheter-related sepsis and/or extensive vascular thrombosis may impede the continuation of a safe and efficient parenteral nutrition and may also require intestinal transplantation in some selected cases. Thus management of patients with intestinal failure requires an early recognition of the condition and the analysis of its risk of irreversibility. Timing of referral for intestinal transplantation remains a crucial issue. As a consequence, management should include therapies adapted to each stage of intestinal failure based on a multidisciplinary approach in centers involving pediatric gastroenterology, parenteral nutrition expertise, home parenteral nutrition program, pediatric surgery, and liver intestinal transplantation program.

Effects of growth hormone on intestinal adaptation of rat with short bowel syndrome

AIM: To evaluate the effects of growth hormone (GH) on the residual small intestine of rats with short bowel syndrome (SBS), including adaptive hyperplasia and absorption of glucose and amino acids.

METHODS: Forty Sprague-Dawley (SD) male rats with more than 85% small intestine resected were equally divided into five groups randomly: H-GH group (high dose at 7.5 IU/kg per day), M-GH group (moderate dose at 3.75 IU/kg per day), L-GH group (low dose at 1.88 IU/kg per day), SBS group and sham operation group. From the second to the 15th day after operation, all the GH-managed groups were treated by sc injection twice a day, while SBS group and sham group were managed with same volume normal saline for injection. All samples were gained by laparotomy under anesthesia at the 16th day after operation.

RESULTS: Weight loss of rats in H-GH group (36±4.4 g), which was the least among the four groups except sham group, was significantly less than that in SBS group (94±10.0 g) (P < 0.05). But preoperative body weight of rats in the four groups except sham group was not retrieved. Among all groups there was no significant difference in the length of jejunum and ileum, as well as no significant difference in the morphological variables of colon. Mucosal height of jejunum and ileum was greater in H-GH group and M-GH group (997±65.9 m, 752±79.3 m and 974±67.6 m, 788±75.1 m respectively) than those in SBS group (776±61.0 m, 664±64.0 m) (P < 0.05). Similarly, intestinal wall width of jejunum and ileum was also thicker in H-GH group and M-GH group (1142±65.4 m, 884±91.2 m and 1 145±78.7 m, 895±95.6 m respectively) than those in SBS group (848±194.7 m, 776±57.5 m) (P < 0.05). But mucosal height and intestinal wall width of jejunum and ileum in H-GH group were not significantly greater than those in M-GH group. Blood insulinlike growth factor 1 (IGF-1) concentration and PCNA index of liver did not differ among the five groups. No significant differences of blood glucose and amino acids concentrations were detected after nutritional administration among the five groups.

CONCLUSION: Treatment of SBS with GH only slows body weight decrease rather than promotes body weight gain by the support of enteral nutrition. GH enhances adaptive mucosal hyperplasia after massive resection of small intestine, while its enhanced effect does not parallel its dose increase. Because of GH resistance resulted from the SBS-induced malnutrition,elevation of blood IGF-1 is impaired and absorpton of glucose and amino acids is not enhanced.

Irreversible intestinal failure

Intestinal failure (IF) can be 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. In developed countries, IF mainly includes individuals with the congenital or early onset of conditions requiring protracted or indefinite parenteral nutrition (PN). Short bowel syndrome was the first commonly recognized cause of protracted IF. The normal physiologic process of intestinal adaptation after extensive resection usually allows for recovery of sufficient intestinal function within weeks to months. During this time, patients can be sustained on parenteral nutrition. Only a few children have permanent intestinal insufficiency and life-long dependency on PN. Non-transplant surgery including small bowel tapering and lengthening may allow weaning from PN in some cases. Hormonal therapy with recombinant human growth hormone has produced poor results while therapy with glucagon-like peptide-2 holds promise. Congenital diseases of enterocyte development such as microvillus inclusion disease or intestinal epithelial dysplasia cause permanent IF for which no curative medical treatment is currently available. Severe and extensive motility disorders such as total or subtotal intestinal aganglionosis (long segment Hirschsprung disease) or chronic intestinal pseudo-obstruction syndrome may also cause permanent IF. PN and home-PN remain are the mainstays of therapy regardless of the cause of IF. Some patients develop complications while receiving long-term PN for IF especially catheter related complications (thrombosis, sepsis) and liver disease. These patients may be candidates for intestinal transplantation. This review discusses the causes of irreversible IF and emphasizes the specific medico-surgical strategies for prevention and treatment of these conditions at several stages of IF.