AIM: To evaluate the effects of bowel rehabilitation and combined trophic therapy on intestinal adaptation in short bowel patients.

METHODS: Thirty-eight patients with severe short-bowel syndrome (SBS) were employed in the present study, whose average length of jejunum-ileum was 35.8 ± 21.2 cm. The TPN treatment was initiated early to attain positive nitrogen balance and prevent severe weight loss. The TPN composition was designated to be individualized and altered when necessary. Enteral feeding was given as soon as possible after resection and increased gradually. Meals were distributed throughout the day. Eight patients received treatment of growth hormone (0.14 mg/kg•d) and glutamine (0.3 g/kg•d) for 3 wk. D-xylose test, ¹⁵N-Gly trace test and ¹³C-palmitic acid breath test were done to determine the patients' absorption capability.

RESULTS: Thirty-three patients maintained well body weight and serum albumin concentration. The average time of follow-up for 33 survival patients was 5.9 ± 4.3 years. Twenty-two patients weaned from TPN with an average TPN time of 9.5 ± 6.6 mo. Two patients, whose whole small bowel, ascending and transverse colon were resected received home TPN. An other 9 patients received parenteral or enteral nutritional support partly as well as oral diet. Three week rhGH + GLN therapy increased nutrients absorption but the effects were transient.

CONCLUSION: By rehabilitation therapy, most short bowel patients could wean from parenteral nutrition. Dietary manipulation is an integral part of the treatment of SBS. Treatment with growth hormone and glutamine may increase nutrients absorption but the effects are not sustained beyond the treatment period.

Short-bowel syndrome (SBS) is resulted from extensive small bowel resection due to infarction of the mesenteric vessels, intestinal volvulus, trauma, malignancy, or from complications of Crohn's disease, and is defined as the manifestations of signs, symptoms and complications associated with the inadequate absorptive surface area of functional bowel[1]. It is usually characterized by severe diarrhea, malabsorption, dehydration, electrolyte and metabolic disturbances, and progressive malnourishment.

The pathophysiological consequences following extensive intestinal resection depend on the length and site of resection and the extent of adaptation of the remaining intestine[2-4]. Patients often have to be supported with total parenteral nutrition (TPN) until maximal adaptation of the residual small bowel is complete. This process can take place for up to a year and sometimes longer. Certain patients may require lifelong TPN support depending on the length and health of the residual small bowel. TPN is associated with certain complications, which include catheter sepsis and liver failure[5-8]. It is therefore important for dietary management and pharmacological treatment in the short bowel patients hopefully to wean from TPN. Dietary management and some trophic factors are important in promoting intestinal adaptation after resection. The aim of the study was to define the role of bowel rehabilitation, trophic factors in intestinal adaptation in short bowel patients.

Thirty-eight patients were admitted and received nutritional support and rehabilitation therapy, among them 2 died of severe malnutrition 2 years after treatment because they failed to receive nutritional therapy, 2 died of accidental event, 1 died of liver failure 5 years later. Thirty-three patients maintained well body weight and serum albumin concentration. The average time of follow-up for 33 survival patients was 5.9 ± 4.3 years (range, 0.5-17 years). Twenty-two patients weaned from TPN, their average TPN time was 9.5 ± 6.6 mo. They maintained their nutritional status well on normal oral diet. Two patients, whose whole small bowel, ascending and transverse colon were resected received home TPN. An other 9 patients received parenteral or enteral nutritional support partly as well as oral diet (Table 1). Eight patients developed gall bladder stones. Cholecystectomy was performed for three patients.

For the eight patients, the 3 wk rhGH + GLN therapy resulted in weight gain, and stool output dramatically decreased. Three patients weaned from TPN completely after the treatment period, 3 patients reduced TPN requirements, and 2 patients failed the therapy. The absorption capability of D-xylose, ¹⁵N-Gly and ¹³C-palmitic acid in these SBS patients was much lower than normal level. After 3 wk rhGH + GLN therapy, the absorption capability of D-xylose, ¹⁵N-Gly and ¹³C-palmitic acid improved. However, it dropped to the level of baseline at one week after treatment (Table 2).

After extensive resection of the small intestine, the remaining bowel, to some degree, had a significant adaptation response to resection. Bowel adaptation, characterized by epithelial hyperplasia and increase in villus diameter, height, and crypt depth, occurred weeks to months after resection[9-11]. Various nutritional and medical therapies can be tried to improve bowel absorptive capacity. TPN is the most important factor responsible for prolonging the lives of patients with SBS. In the initial stages after massive resection of bowel, TPN should begin early to attain positive nitrogen balance and to prevent severe weight loss[12,13]. TPN has been shown to greatly increase the chances of long-term survival. It should be delivered until the adaptive processes were complete or indefinitely, if clinically indicated[14]. This process can take place for up to a year and sometimes longer. Long-term TPN resulted in small bowel mucosa atrophy and was associated with certain complications, such as catheter sepsis and liver failure[15]. So, oral diet is encouraged, if there is any absorptive capacity of the remaining bowel, bowel adaptation should be promoted. An enteral tube feeding might be used to supplement the diet in an effort to wean patients from TPN[16]. At first, diluted solutions of chemically defined diets containing simple amino acids and short-chain peptides were offered. Gradually, the diet with intact protein nutrient formulas and dietary fiber was given in accordance with the patients' need. The parenteral supply had to be adjusted according to the oral intake. As the patient's oral intake increased, the amount of TPN was reduced, the frequency of TPN was reduced to every other day for 1 wk, three times in the next week, and twice during the third week or weaned from TPN at last[17]. If the patient lost or more 1 kg/wk of body weight or more, if diarrhea exceeded 600 g/d or if laboratory abnormalities developed, then the patients were placed back on TPN[18]. In our group, 22 patients weaned from TPN among the 33 survived patients after receiving rehabilitation therapy. They maintained their nutritional status well on normal oral diet. It indicated that rehabilitation therapy for SBS played important roles in the intestinal adaptation.

Combination of glutamine, human recombinant growth hormone has been shown to influence bowel adaptation[19-24]. The study by Byrne et al[25,26] indicated that at one year of follow-up 40% of treated patients were able to reduce or discontinue parenteral nutrition. Patients in the study were also receiving other medical therapy, including medications known to slow down intestinal motility and oral rehydration solutions. It is not clear whether glutamine, growth hormone, diet, or other factors contributed to the favorable outcome. It did not necessarily mean that fluid and nutrients absorption was increased because absorptive studies were not performed. Szkudlarek et al[27] reported in a randomized control study of eight short-bowel patients the combination of growth hormone and glutamine for 28 d did not result in a significant increase in fluid or nutrient absorption. In our clinical trial, we used D-xylose test, ¹⁵N-Gly trace test and ¹³C-palmitic acid breath test to determine the patients' nutrient absorption capability. The results showed that the absorption of carbohydrates (from 5.4% to 7.6%), protein (from 62.4% to 73.2%) and fat (from 55.3% to 64.5%) increased. Weight gain was observed and stool output dramatically decreased. Three patients weaned from TPN completely after the treatment period and 3 patients reduced TPN requirements. However, the absorption capability dropped to the level of baseline at one week after treatment. We found that the treatment with growth hormone and glutamine might increase absorption of nutrients but the effect seemed to be transient with no long term improvement in gut function when treatment was discontinued. This has been supported by recent clinical studies[28-30].

In conclusion, by rehabilitation therapy, most short bowel patients could wean from parenteral nutrition. Dietary manipulation is an integral part of the treatment of SBS. Treatment with growth hormone and glutamine may increase nutrients absorption but the effects are not sustained beyond the treatment period. Therapeutic efficacy can be achieved only when the treatment plan is tailored to meet individual need.