An analysis of the morbidity and mortality of short-bowel syndrome in the pediatric age group

Small and large bowel anatomy is associated with enteral autonomy in infants with short bowel syndrome: A retrospective cohort study

BACKGROUND

Achievement of enteral autonomy (EA) is the ultimate treatment goal in pediatric intestinal failure (IF). We aimed to assess predictors of EA in pediatric short bowel syndrome (SBS) and explore the impact of residual small bowel (SB) and large bowel (LB) length on EA.

METHODS

A retrospective cohort study was performed on infants aged <12 months (n = 367, six centers) with SBS referred between 2010 and 2015. The cohort was stratified based on the achievement of EA. Statistical testing was completed using t-test, chi-square, Cox proportional hazards regression model, and Kaplan-Meier analysis.

RESULTS

EA was achieved in 229 patients. In the multivariable analysis, the percentage of residual LB (hazard ratio [HR] = 1.02; 95% CI = 1.01-1.02) and SB (HR = 1.01; 95% CI = 1.01-1.02) length, presence of the ileocecal valve (HR = 2.02; 95% CI=1.41-2.88), and not coming from a high-volume transplantation center (HR = 2.42; 95% CI = 1.68-3.49) were positively associated with EA, whereas a negative association was seen with the presence of stoma at the time when shortest remnant was documented (HR = 0.72; 95% CI = 0.52-1.00). EA achievement was significantly different between the anatomical subgroups (log-rank test P < 0.001) with an EA rate of 80.4% in infants with ≥50% SB and LB (median time 209 days); 62.5% with ≥50% SB and <50% LB (397 days); 58.3% with <50% SB and ≥50% LB (1192 days), and 25.9% with <50% SB and LB. Necrotizing enterocolitis (NEC) was not associated with a better achievement of EA (NEC vs other etiologies: log-rank test P = 0.33).

CONCLUSIONS

Overall, 62% of infants with IF secondary to SBS achieved EA over a mean time of follow-up of 2.3 years. A colon length of >50% can compensate for the loss of small bowel (<50%) and account for similar EA rates as those in children with residual SB > 50%.

Intestinal dysmotility after bowel resection in rats is associated with decreased ghrelin and vimentin expression and loss of intestinal cells of Cajal

This study provides novel insight into the mechanisms of intestinal dysmotility following massive small bowel resection. We show that 2 wk after bowel resection in rats, impaired intestinal motility was associated with loss of interstitial cells of Cajal (ICC; downregulation of transmembrane member 16A (TMEM16A) and c-kit expression) as well as with decreased vimentin, desmin, and ghrelin levels. Impaired intestinal motility led to a decrease in final body weight, suggesting less effective nutrient absorption. The purpose of this study was to evaluate the mechanisms of intestinal motility in a rat model of short bowel syndrome (SBS). Rats were divided into three groups: Sham rats underwent bowel transection; SBS-NSI rats underwent a 75% bowel resection and presented with normal intestinal size (NSI) at euthanasia and hypermotility patterns; SBS-DYS showed dysmotile (DYS) enlarged intestine and inhibited motility patterns. Animals were euthanized after 2 wk. Illumina's digital gene expression (DGE) analysis was used to determine the intestinal motility-related gene expression profiling in mucosal samples. Intestinal motility-related and ICC genes and protein expression in intestinal muscle layer were determined using real-time PCR, Western blotting, and immunohistochemistry. Gastrointestinal tract motility was studied by microcomputer tomography. From 10 Ca²⁺ signaling pathway-related genes, six genes in jejunum and seven genes in ileum were downregulated in SBS vs. Sham animals. Downregulation of TMEM16A mRNA and protein was confirmed by real-time PCR. Rapid intestinal transit time in SBS-NSI rats correlated with a mild decrease in TMEM16A, c-kit, and vimentin mRNA and protein expression (vs/. Sham animals). SBS-DYS rats demonstrated enlarged intestinal loops and delayed small intestinal emptying (on imaging studies) that were correlated with marked downregulation in TMEM16A, c-kit, vimentin, and ghrelin mRNA and protein levels compared with the other two groups. In conclusion, 2 wk following massive bowel resection in rats, impaired intestinal motility was associated with decreased vimentin and ghrelin gene and protein levels as well as loss of ICC (c-kit and TMEM16A).NEW & NOTEWORTHY This study provides novel insight into the mechanisms of intestinal dysmotility following massive small bowel resection. We show that 2 weeks after bowel resection in rats, impaired intestinal motility was associated with loss of interstitial cells of Cajal (downregulation of TMEM 16A, and c-kit expression) as well as with decreased vimentin, desmin, and ghrelin levels. Impaired intestinal motility led to decrease in final body weight, suggesting less effective nutrient absorption.

Non-transplant Surgical Management of Short Bowel Syndrome in Children: An Overview

Management of severe Short Bowel Syndrome (SBS) is still one of the largest challenges of the medicine. Vast majority of the short bowel patients are children, the conditions that lead to this possible outcome most often are necrotizing enterocolitis (NEC), small intestinal volvulus as a result of intestinal malrotation, gastroschisis and the "apple peel" syndrome. Therefore, paediatricians and paediatric surgeons face this challenge most often. The nontransplant treatment appears to be effective using surgical procedure to increase absorptive surface and to reduce the transit time, but in some cases these procedures are enough to weaning of TPN. The aim of this review was to summarize the modern non-stransplant surgical management of short bowel syndrome.

Surgical strategies in short bowel syndrome

Extensive loss of small bowel in all age groups has significant morbidity and mortality consequences. Despite the astonishing ability of the small bowel to compensate for an extensive loss, long-term parenteral nutrition and enteral nutrition, tailored to the need of the patients in relation to the missing intestinal regions is needed. Organ-preserving surgical intervention becomes necessary in patients with a very short intestinal transit time and in an other group of patients with impaired propulsive peristalsis. Intestinal transplantation is indicated in recurrent septical infections or if nearly all of the small bowel is missing. This review discusses indications and risks of the organ-preserving surgical therapies in children with short bowel syndrome.

Effect of bowel resection on TLR signaling during intestinal adaptation in a rat model

BACKGROUND

Bacterial overgrowth is common complication of short bowel syndrome (SBS) and is a result of an impaired gut barrier function. Toll-like receptor 4 (TLR4) is crucial in maintaining intestinal epithelial homeostasis, participates in a vigorous signaling process and heightens inflammatory cytokine output. The objective of this study was to determine the effects of bowel resection on TLR4 signaling in intestinal mucosa in a rat model.

METHODS

Male Sprague-Dawley rats were randomly assigned to one of the two experimental groups of eight rats each: Sham rats underwent bowel transection and re-anastomosis and SBS rats underwent 75 % small bowel resection. Rats were killed on day 14. Bacterial translocation (BT) to mesenteric lymph nodes, liver, portal blood and peripheral blood was determined at the kill. The expression of TLR4, MyD88 and TRAF6 in the intestinal mucosa was determined using real-time PCR, Western blot and immunohistochemistry.

RESULTS

SBS rats demonstrated a 100 % BT to lymph nodes and to liver (Level I), 80 % translocation to portal blood (Level II) and 60 % translocation to peripheral blood (Level III) at day 7 as well as a 100 % BT to lymph nodes and liver, and 40 % translocation to peripheral blood at day 14. Microarray expression profiling demonstrated that most of the TLR signaling-related genes were up-regulated in resected rats compared to control animals. SBS rats showed a significant increase in TLR4 and TRAF6 mRNA in jejunum and ileum, TLR4 and MyD88 protein expression in jejunum and ileum, and a significant increase in the number of TLR4 and TRAF6 positive cells (immunohistochemistry) compared to sham animals.

CONCLUSIONS

In a rat model of SBS, elevated intestinal BT is associated with a stimulated TLR4 signaling.

Wnt/β-catenin signaling cascade down-regulation following massive small bowel resection in a rat

BACKGROUND

Growing evidence suggests that the Wnt/β-catenin signaling cascade is implicated in the control of stem cell activity, cell proliferation, lineage commitment, and cell survival during normal development and tissue regeneration of the gastrointestinal epithelium. The roles of this signaling cascade in stimulation of cell proliferation after massive small bowel resection are unknown. The purpose of this study was to evaluate the role of Wnt/β-catenin signaling during late stages of intestinal adaptation in a rat model of short bowel syndrome (SBS).

METHODS

Male rats were divided into two groups: sham rats underwent bowel transection and SBS rats underwent a 75 % bowel resection. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined 2 weeks after operation. Illumina's digital gene expression analysis was used to determine Wnt/β-catenin signaling gene expression profiling. Twelve Wnt/β-catenin-related genes and β-catenin protein expression were determined using real-time PCR, western blotting and immunohistochemistry.

RESULTS

From the total number of 20,000 probes, 20 genes related to Wnt/β-catenin signaling were investigated. From these genes, seven genes were found to be up-regulated and eight genes to be down-regulated in SBS vs. sham animals with a relative change in gene expression level of 20 % or more. From 12 genes determined by real-time PCR, nine genes were down-regulated in SBS rats compared to control animals including target gene c-Myc. SBS rats also showed a significant decrease in β-catenin protein compared to control animals.

CONCLUSION

Two weeks following massive bowel resection in rats, Wnt/β-catenin signaling pathway is inhibited. In addition, it appears that cell differentiation rather than proliferation is most important in the late stages of intestinal adaptation.

Management of short bowel syndrome

Most intestinal failure in children is due to short bowel syndrome (SBS) where congenital or acquired lesions have led to an extensive loss of intestinal mass. The vast majority of morbidity and mortality of patients with SBS is due to complications secondary to their long term dependence on parenteral nutrition. In response to SBS, the intestine undergoes a process of remodeling termed adaptation. Principles guiding the medical management of SBS include providing adequate parenteral nutrition, fluids and electrolytes for growth and normal development, promoting small bowel adaptation, and preventing and treating complications related to the patient's underlying disease and their parenteral nutrition. Catheter associated blood stream infection (CABSI) is major source of morbidity and mortality in patients with intestinal failure from SBS. Intestinal failure associated liver disease (IFALD)is another major source of morbidity and mortality in patients with SBS. IFALD is the most consistent negative predictor of outcome including death and continued parenteral nutrition dependence. Enteral nutrition is critical for intestinal adaptation and preventing IFALD. Patients with SBS who develop dilated dysmotile segments may benefit from autologous intestinal reconstruction surgery (AIRS) with the goal of decreasing stasis and disordered motility through intestinal narrowing and lengthening. Patients with SBS should be referred for transplantation if they have failed intestinal rehabilitation including AIRS, have no reasonable chance for enteral feeding tolerance, develop irreversible IFALD, have recurrent sepsis, or have exhausted their central venous access sites. With improvements in medical and surgical care, overall survival of patients with SBS now exceeds 90%.

Ultrashort bowel syndrome in children

OBJECTIVE

Recent data have demonstrated improved survival in children with intestinal failure. We hypothesized that this trend would also be observed in children with ultrashort bowel syndrome.

METHODS

A prospective database from Seattle Children's Intestinal Failure Program was used to evaluate outcomes and morbidities of consecutive patients with 10 cm or less of small bowel enrolled in the program since 2005. Data are listed as median (range).

RESULTS

Five patients were identified with a bowel length of 6 (1-10) cm and follow-up of 54 (43-61) months. All children have survived and are currently between 3.5 and 5.5 years of age. One patient underwent isolated intestinal transplantation and one patient is currently listed for intestinal transplantation. The transplanted child is fully enterally fed. The other patients remain at least partially dependent on parenteral nutrition. None of these patients have current evidence of parenteral nutrition-associated liver disease. Patients have required extensive care after referral to our program, including 18 (15-32) visits to the emergency room, 152 (114-273) days of inpatient care, and 6 (5-9) central line-associated blood stream infections.

CONCLUSIONS

Long-term survival in children with ultrashort bowel length is possible after referral to an intestinal failure program, although extensive medical management is required. These children may be reasonable candidates for long-standing intestinal rehabilitation as a bridge to intestinal transplantation.

Dietary supplementation with vitamin D stimulates intestinal epithelial cell turnover after massive small bowel resection in rats

PURPOSE

While the endocrine action of the active metabolite 1,25-dihydroxyvitamin D (VtD) has been well characterized in relation to the maintenance of plasma calcium and phosphate homeostasis through regulation of intestinal absorption, recent research has focused on its autocrine and/or paracrine activities. Such activities have been best characterized in intestine, where VtD regulates cell differentiation and maturation. The purpose of this study was to evaluate the effect of VtD on enterocyte turnover in a rat model of short bowel syndrome (SBS).

METHODS

Male rats were divided into four groups: sham rats underwent bowel transection, sham-VtD rats underwent bowel transection and were treated oral VtD, SBS rats underwent a 75 % bowel resection, and SBS-VtD rats underwent bowel resection and were treated with VtD. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at sacrifice. Illumina's digital gene expression (DGE) analysis was used to determine VtD pathway-related gene expression profiling. VtD receptor (VDR) and its promoter, Bax and Bcl-2 mRNA expression were determined using real-time PCR. Western blotting was used to determine p-ERK, Bax and β-catenin protein levels.

RESULTS

From the total of 20,000 probes, 11 genes related to VtD signaling were investigated. Of these genes, five were found to be up-regulated in SBS versus sham animals with a relative change in gene expression level of 20 %, five remained unchanged, and one was down-regulated. VtD treatment in sham and SBS rats resulted in significant up-regulation of the VDR gene and its promoter's expression. SBS-VtD rats demonstrated a significant increase in all intestinal mucosal parameters compared to SBS animals. A significant increase in cell proliferation in SBS-VtD rats was accompanied by increased β-catenin protein levels. A significant decrease in cell apoptosis in this group was correlated with lower Bax/Bcl-2 mRNA and protein levels.

CONCLUSION

In a rat model of SBS, dietary supplementation with VtD stimulates enterocyte turnover, which correlates with up-regulated VtD receptor expression in the remaining small intestine.

TGF-β affects enterocyte turnover in correlation with TGF-β receptor expression after massive small bowel resection

OBJECTIVES

In the present study, we evaluated the effect of transforming growth factor-beta 2 (TGF-β2)-enriched diet on enterocyte turnover and correlated it with TGF-β2 receptor expression along the villus-crypt axis in a rat model of short bowel syndrome (SBS).

METHODS

CaCo-2 cells were incubated with increasing concentrations of TGF-β2. Alamar Blue reduction test was used for investigation of cell viability and evaluation of cell apoptosis was assessed by flow cytometry. Male rats were divided into 4 groups: Sham rats underwent bowel transection, Sham TGF-β rats were treated with diet enriched with TGF-β2, SBS rats underwent a 75% bowel resection, and SBS TGF-β rats were fed a diet enriched with TGF-β2 after bowel resection. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined at sacrifice. TGF-β2r expression in villus tips, lateral villi and crypts was assessed by immunohistochemistry. The effect of TGF-β2 on enterocyte turnover for each compartment was evaluated in correlation with TGF-β2r expression.

RESULTS

Incubation of CaCo-2 cells with TGF-β2 resulted in a significant decrease in cell viability and increased cell apoptosis. TGF-β2r expression in crypts increased in SBS rats (vs sham) and was accompanied by decreased cell proliferation and increased cell apoptosis following TGF-β2 administration. A significant decrease in TGF-β2r expression at villous tips in SBS rats was accompanied by a decreased cell apoptosis in this compartment following exposure to TGF-β2-enriched diet.

CONCLUSIONS

In a rat model of SBS, the inhibiting effect of TGF-β2 on enterocyte turnover correlates with TGF-β2 receptor expression along the villus-crypt axis.

Oral insulin stimulates intestinal epithelial cell turnover following massive small bowel resection in a rat and a cell culture model

PURPOSE

We have recently reported that oral insulin (OI) stimulates intestinal adaptation after bowel resection and that OI enhances enterocyte turnover in correlation with insulin receptor expression along the villus-crypt axis. The purpose of the present study was to evaluate the effect of OI on intestinal epithelial cell proliferation and apoptosis in a rat model of short bowel syndrome (SBS) and in a cell culture model.

METHODS

Caco-2 cells were incubated with increasing concentrations of insulin. Cell proliferation and apoptosis were determined by FACS cytometry. Cell viability was investigated using the Alamar Blue technique. Male rats were divided into three groups: Sham rats underwent bowel transection, SBS rats underwent a 75% bowel resection, and SBS-OI rats underwent bowel resection and were treated with OI given in drinking water (1 U/ml) from the third postoperative day. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined on day 15. Real time PCR was used to determine the level of bax and bcl-2 mRNA and western blotting was used to determine bax, bcl-2, p-ERK and AKT protein levels. Statistical analysis was performed using the one-way ANOVA test, with P < 0.05 considered statistically significant.

RESULTS

Treatment of Caco-2 cells with insulin resulted in a significant increase in cell proliferation (twofold increase after 24 h and 37% increase after 48 h) and cell viability (in a dose-dependent manner), but did not change cell apoptosis. In a rat model of SBS, treatment with OI resulted in a significant increase in all parameters of intestinal adaptation. Elevated cell proliferation rate in insulin treated rats was accompanied by elevated AKT and p-ERK protein levels. Decreased cell apoptosis in SBS-INS rats corresponded with a decreased bax/bcl-2 ratio.

CONCLUSIONS

Oral insulin stimulates intestinal epithelial cell turnover after massive small bowel resection in a rat model of SBS and a cell culture model.

Effect of alpha-naphthylisothiocyanate-induced liver injury on intestinal adaptation in a rat model of short bowel syndrome

BACKGROUND/PURPOSE

Progressive hyperbilirubinemia and end-stage liver failure are among the most serious complications of short bowel syndrome (SBS), representing the principle cause of death in a majority of fatal cases. In the current study, we examined the effects of alpha-naphthylisothiocyanate (ANIT)-induced liver injury on intestinal adaptation in a rat model of SBS.

METHODS

Male rats were divided into four groups: Sham rats underwent bowel transection (n = 8), Sham liver-injury rats underwent bowel transection and IP injection of ANIT (100 mg/kg, n = 8), SBS rats underwent a 75% bowel resection, and SBS-ANIT rats underwent bowel resection and liver injury similar to group sham-ANIT (n = 8). Fourteen days after intervention, liver biopsies and intestinal samples were obtained and evaluated for liver damage and measures of intestinal adaptation. Real time PCR and Western blotting were used to determine the level of bax and bcl-2 mRNA and protein, and p-ERK protein levels. Statistical analysis was performed using the one-way ANOVA test, with p < 0.05 considered statistically significant.

RESULTS

All ANIT-treated animals exhibited histological evidence of liver damage that was associated with the expansion of atypical ductal proliferation near the periportal areas, intense neutrophil infiltration in the liver, increased mitotic activity, Kupfer cells hyperplasia and fatty liver degeneration. ANIT-induced liver damage in bowel resected animals was associated with a significant decrease in all parameters of intestinal adaptation including bowel and mucosal weight in jejunum (twofold decrease) and ileum (twofold decrease), mucosal DNA in jejunum (fourfold decrease), mucosal protein in jejunum (threefold decrease) and ileum (threefold decrease), villus height in jejunum (38%) and ileum (34%), and crypt depth in jejunum (24%) and ileum (30%) compared to SBS animals. Both Sham-ANIT and SBS-ANIT rats demonstrated decreased enterocyte proliferation rates that were accompanied by decreased p-ERK protein levels. Lower apoptotic rates in jejunum (40%) and ileum (52%) in SBS-ANIT rats (vs. SBS) coincided with decreased bax mRNA and protein levels.

CONCLUSIONS

In a rat model of SBS, ANIT-induced liver injury was associated with decreased enterocyte proliferation and inhibited intestinal adaptation.

Differential protein expression during colonic adaptation in ultra-short bowel rats

AIM: To investigate the proteins involved in colonic adaptation and molecular mechanisms of colonic adaptation in rats with ultra-short bowel syndrome (USBS).

METHODS: Sprague Dawley rats were randomly assigned to three groups: USBS group (10 rats) undergoing an approximately 90%-95% small bowel resection; sham-operation group (10 rats) undergoing small bowel transaction and anastomosis; and control group (ten normal rats). Colon morphology and differential protein expression was analyzed after rats were given post-surgical enteral nutrition for 21 d. Protein expression in the colonic mucosa was analyzed by two-dimensional electrophoresis (2-DE) in all groups. Differential protein spots were detected by ImageMaster 2D Platinum software and were further analyzed with matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight-mass spectrometric (MALDI-TOF/TOF-MS) analysis.

RESULTS: The colonic mucosal thickness significantly increased in the USBS group compared with the control group (302.1 ± 16.9 μm vs 273.7 ± 16.0 μm, P < 0.05). There was no statistically significant difference between the sham-operation group and control group (P > 0.05). The height of colon plica markedly improved in USBS group compared with the control group (998.4 ± 81.2 μm vs 883.4 ± 39.0 μm, P < 0.05). There was no statistically significant difference between the sham-operation and control groups (P > 0.05). A total of 141 differential protein spots were found in the USBS group. Forty-nine of these spots were down-regulated while 92 protein spots were up-regulated by over 2-folds. There were 133 differential protein spots in USBS group. Thirty of these spots were down-regulated and 103 were up-regulated. There were 47 common differential protein spots among the three groups, including 17 down-regulated protein spots and 30 up-regulated spots. Among 47 differential spots, eight up-regulated proteins were identified by MALDI-TOF/TOF-MS. These proteins were previously reported to be involved in sugar and fat metabolism, protein synthesis and oxidation reduction, which are associated with colonic adaption.

CONCLUSION: Eight proteins found in this study play important roles in colonic compensation and are associated with sugar and fat metabolism, protein synthesis, and molecular chaperoning

Parenteral but not enteral omega-3 fatty acids (Omegaven) modulate intestinal regrowth after massive small bowel resection in rats

BACKGROUND

The purpose of the present study was to evaluate the effects of ω-3 fatty acids (Omegaven) on early intestinal adaptation in rats with short bowel syndrome (SBS).

METHODS

Male Sprague-Dawley rats were randomly assigned to 1 of 4 groups: sham rats underwent bowel transection; SBS rats underwent 75% bowel resection; SBS-O ω-3 rats underwent bowel resection and were treated with oral Omegaven given by gavage; and SBS-I ω-3 rats underwent bowel resection and were treated with Omegaven given intraperitoneally. Rats were killed on day 14. Parameters of intestinal adaptation (bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depths, cell proliferation and apoptosis) were determined at time of death. Real-time polymerase chain reaction was used to determine the level of Bax and Bcl-2 messenger RNA (mRNA). Statistical analysis was performed using Kruskal-Wallis test followed by post hoc test, with P < .05 considered statistically significant.

RESULTS

Oral ω-3 supplementation did not significantly change intestinal regrowth. In contrast, parenteral ω-3 in rats that underwent resection resulted in higher bowel and mucosal weights, mucosal DNA and protein in ileum, villus height in ileum, crypt depth in jejunum and ileum, and greater rates of cell proliferation in jejunum and ileum compared with SBS animals. The initial decreased levels of apoptosis corresponded with the early decrease in Bax and increase in Bcl-2 mRNA levels.

CONCLUSIONS

Parenteral but not enteral Omegaven augments and accelerates structural bowel adaptation in a rat model of SBS. Increased cell proliferation and decreased apoptosis reflect increased cell turnover in Omegaven-treated animals.

Clinical assessment of the child with intestinal failure

The management of the child with intestinal failure is complex, and it is developing into a multispecialty field of its own led by expert teams of both transplant and nontransplant surgeons, gastroenterologists, and dieticians. Patients are at risk for medical, surgical, and nutritional complications that should be anticipated so that they can be prevented or managed appropriately. Catheter associated infections and intestinal failure associated liver diseases are important complications that impact the likelihood of bowel adaptation and long-term survival. The clinical assessment of a pediatric intestinal failure patient should include evaluation of the child within the context of recognized prognostic factors.

Oral insulin stimulates intestinal epithelial cell turnover in correlation with insulin-receptor expression along the villus-crypt axis in a rat model of short bowel syndrome

PURPOSE

It has been reported that oral insulin (OI) has a trophic effect on intestinal mucosa. In the present study, we evaluated the effect of OI on enterocyte turnover and correlated it with insulin-receptor expression along the villus-crypt axis in a rat model of short bowel syndrome (SBS).

METHODS

Male rats were divided into three groups: Sham rats underwent bowel transection, SBS rats underwent a 75% bowel resection, and SBS-OI rats underwent bowel resection and were treated with OI given in drinking water (1 U/ml) from the fourth postoperative day. Parameters of intestinal adaptation, enterocyte proliferation and apoptosis were determined on day 15. Real-time PCR was used to determine the level of insulin receptor-beta (IRB) mRNA. Insulin-receptor expression along the villus-crypt axis (villus tips, lateral villi and crypts) was assessed by immunohistochemistry. The effect of OI on cell turnover for each compartment was evaluated in correlation with the receptor expression. Statistical analysis was performed using the one-way ANOVA test, with P < 0.05 considered statistically significant.

RESULTS

Treatment with OI resulted in a significant increase in all parameters of intestinal adaptation. Insulin-receptor expression in crypts significantly increased in SBS rats (vs. Sham rats) and was accompanied by a significant increase in enterocyte proliferation following OI administration. A significant increase in insulin-receptor expression at the tip of the villous and in the lateral villous in SBS rats (vs. Sham) was accompanied by decreased cell apoptosis in these compartments following treatment with OI.

CONCLUSIONS

In a rat model of SBS, OI enhances enterocyte turnover and stimulates intestinal adaptation. The stimulating effect of insulin on enterocyte turnover correlates with insulin-receptor expression along the villus-crypt axis.

Bilirubin impairs intestinal regrowth following massive small bowel resection in a rat model

OBJECTIVES

The purpose of the present study was to evaluate the effects of exogenous bilirubin on structural intestinal adaptation, cell proliferation, and apoptosis in a rat model of short bowel syndrome (SBS).

MATERIALS AND METHODS

Male Sprague-Dawley rats were divided into 5 experimental groups: Sham rats underwent bowel transection and reanastomosis, sham multiple doses of bilirubin (MDB) rats underwent bowel transection and were treated with bilirubin, SBS rats underwent a 75% small bowel resection, SBS-SDB (single dose bilirubin) rats underwent a bowel resection and were treated with a single dose of bilirubin, and SBS-MDB underwent a bowel resection and were treated with 3 doses of bilirubin. Bilirubin was administered intraperitoneally from the 7th day through the 14th day postoperatively. Serum total bilirubin concentration over time was evaluated in 5 SBS-SDB rats following a single intraperitoneal dose. Total bilirubin, alanine aminotransferase, and aspartate aminotransferase in serum and parameters of intestinal adaptation, enterocyte proliferation, and enterocyte apoptosis were determined on day 15.

RESULTS

SBS-SDB and SBS-MDB animals demonstrated lower ileal bowel and mucosal weights, jejunal mucosal DNA and ileal mucosal protein, and jejunal and ileal villus height and crypt depth (vs SBS animals). Bilirubin-treated rats showed a lower apoptotic index in jejunum and ileum and a trend toward an increase in cell proliferation in jejunum and ileum (vs SBS group).

CONCLUSIONS

In a rat model of SBS, exogenous bilirubin inhibits structural intestinal adaptation. Increased cell proliferation and decreased apoptosis may be considered adaptive mechanisms that maintain cell mass.

Oral insulin supplementation in paediatric short bowel disease: a pilot observational study

BACKGROUND AND AIM

Insulin is present in human milk, and oral insulin supplementation causes a dramatic adaptive gut growth in a rat model of short bowel syndrome (SBS). We conducted an open-label pilot observational study to examine whether oral insulin supplementation to paediatric patients with SBS decreases the need for parenteral nutrition (PN).

METHODS

Between April 2004 and March 2006, 10 premature infants and children were recruited from 8 paediatric gastroenterology centres in Israel, Croatia, and Germany. Enrolled subjects received 1 unit of insulin (Actrapid, Novonordisk, Denmark)/kg body weight per dose x 4/day (every 6 hours) for 28 days. We monitored glucose blood levels, weight, enteral and parenteral intake of calories, carbohydrates, and lipids. In addition, blood levels of albumin, ALT, AST, GGT, ALP, total cholesterol, triglycerides, and anti-insulin antibodies were recorded.

RESULTS

On average, enteral intake increased from 45.6% +/- 30.6% to 58.9% +/- 28.2% (not statistically significant), and ALT blood levels decreased from 194 +/- 128 U to 136 +/- 79 U (not statistically significant). Two (2/10) infants were weaned off PN. None of the children developed insulin antibodies.

CONCLUSIONS

Oral insulin supplementation in paediatric SBS is not associated with short-term side effects. Although clinical improvement was observed in a subset of children, whether these effects are due to insulin administration is uncertain. The efficacy of oral insulin remains to be determined in a double-blind manner using a preparation that is resistant to degradation in the stomach.

10-year review of pediatric intestinal failure: clinical factors associated with outcome

Prediction of outcomes in pediatric intestinal failure is challenging but essential to guide intestinal rehabilitation and transplantation decisions. This review of intestinal failure patients spanning 10 years examines clinical details in relation to outcome to identify factors that may refine predictive accuracy. A search was conducted to identify all children with intestinal failure managed at Stollery Children's Hospital between January 1994 and December 2003. They were divided into 3 groups: early death occurring <or=30 days of age, parenteral nutrition dependence for 30-100 days, and parenteral nutrition dependence for >100 days. The long-term group was divided according to outcome: death or adaptation. Demographics, diagnosis, nutrition requirements, laboratory parameters, and clinical data were recorded. Groups were compared to identify factors associated with outcome. Necrotizing enterocolitis, gastroschisis, and intestinal atresias were the most common causes for intestinal failure; outcome was not related to diagnosis. Although withdrawal of therapy was common in the early death group, most babies had one or more additional significant comorbidity. Among the 29 babies requiring parenteral nutrition for >100 days with known outcomes, 12 died, 16 adapted fully, and 1 received a multivisceral transplant. Intestinal length >40 cm was associated with a significantly increased risk of mortality (P< .001). Abnormal laboratory values (bilirubin, aspartate aminotransferase, alanine aminotransferase, albumin, and platelet count) after 5 months of age were also significantly different between groups. This data, together with data from previous reviews, should be used to investigate potential predictive factors in prospective studies, particularly in the context of expert multidisciplinary care.

Irreversible intestinal failure: prevalence and prognostic factors

BACKGROUND AND AIM

Parenteral nutrition (PN) is the primary treatment for intestinal failure, which is considered irreversible in patients who remain partially or fully dependent on PN. Causes of irreversible intestinal failure are short bowel syndrome (SBS), motility disorders (MD), and severe protracted diarrhea (SPD). The aim of this study was to report the clinical outcome in these patients in relation to the underlying disease.

PATIENTS AND METHODS

From January 1, 1989 to December 31, 2006, 218 intestinal failure patients were observed in our center, but only 96 (48 SBS, 39 SPD, and 9 MD) were included because they required at least 50% of their total calories as PN for not less than 3 months. In these patients, survival and complication rates were evaluated.

RESULTS

The survival rate was significantly higher in SBS patients than in the other groups (P < 0.01). SBS patients showed a higher rate of major complications, although only intestinal failure-associated liver disease was significantly higher (P < 0.001). In our series, MD was the main cause of irreversible intestinal failure.

CONCLUSIONS

The potential for bowel adaptation is higher in surgical than in medical causes of intestinal failure and does not seem to be influenced by complications of intestinal failure. SBS, although worsened by the major number of complications, was not the main category contributing to intestinal failure.

Factors affecting survival to intestinal transplantation in the very young pediatric patient

BACKGROUND

Very young pediatric patients awaiting intestinal transplantation have a high mortality rate due to long waiting times, scarcity of appropriate size donor organs, and mortality due to sepsis and liver failure. To investigate specific risk factors impacting survival to intestinal transplantation, we performed a 4-year institutional retrospective study comparing children who received grafts by age 18 months with children 18 months or younger who died while on the waiting list.

PATIENTS AND METHODS

Twelve children comprised the transplanted group and had the underlying diagnoses: necrotizing enterocolitis, gastroschisis, Hirschsprung's disease, and omphalocele. Ten children comprised the deceased group and had the underlying diagnoses: intestinal atresia, necrotizing enterocolitis, gastroschisis, and midgut volvulus. Multiple risk factors were assessed in these groups.

RESULTS

No differences in residual small bowel length, presence of the colon, number of line infections, or number of central lines were found. The average body weight of the transplanted group trended higher, whereas the deceased group had more impairment of hepatic function. Intestinal atresia was the most common diagnosis in the deceased group while none of the transplanted group carried this diagnosis. Ileocecal valve was retained in 80% of the deceased group and in none of the transplanted group.

CONCLUSIONS

In children younger than 18 months, risk factors affecting survival to intestinal transplantation include small body size and advanced liver disease. A primary diagnosis of intestinal atresia and the presence of the ileocecal valve may confer additional risk to these very young children.

Effect of probiotics on intestinal regrowth and bacterial translocation after massive small bowel resection in a rat

BACKGROUND/PURPOSE

Because of their ability to inhibit intestinal bacterial overgrowth, probiotics (PROs) have been advocated for the treatment of patients with short bowel syndrome (SBS). This study was conducted to determine the effect of PROs on bacterial translocation and intestinal regrowth after massive small bowel resection in a rat.

METHODS

Male Sprague-Dawley rats were divided into 3 experimental groups: sham rats underwent bowel transection and reanastomosis, SBS rats underwent 75% small bowel resection, and SBS-PRO rats underwent bowel resection and were treated with a PRO given in drinking water from day 4 through 14. Intestinal structural changes (bowel circumference, overall bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depth, enterocyte proliferation and enterocyte apoptosis) and bacterial translocation (BT) to mesenteric lymph nodes, liver, portal blood, and peripheral blood were determined on day 15 after operation.

RESULTS

Sham rats exhibited a 20% BT to the mesenteric lymph nodes (level I), liver (level II), and blood (level III). Short bowel syndrome rats demonstrated a 100% BT to lymph nodes (level I) and liver (level II) and 40% translocation to peripheral blood (level III). Treatment with PROs resulted in a significant decrease in BT to all 3 target organs and decreased enterocyte apoptosis compared with SBS-untreated animals. Short bowel syndrome rats showed a significant increase (vs sham) in jejunal and ileal bowel and mucosal weight, mucosal DNA and protein, villus height, and crypt depth. Short bowel syndrome rats also had a greater proliferation index and apoptotic index in both jejunum and ileum compared with sham animals. SBS-PRO rats showed a significant increase (vs SBS rats) in crypt depth in ileum and a mild decrease in apoptotic index in jejunum and ileum, compared with SBS-untreated animals.

CONCLUSIONS

In a rat model of SBS, PROs decrease BT through mechanisms which maybe dependent on intestinal mucosal integrity.

Bombesin stimulates enterocyte turnover following massive small bowel resection in a rat

Recent evidence suggests that bombesin (BBS) is involved in modulation of growth and differentiation of normal small intestine. The purpose of the present study was to evaluate the effects of BBS on enterocyte turnover after massive small bowel resection in a rat. Male Sprague-Dawley rats were divided into three experimental groups: Sham rats underwent bowel transection and re-anastomosis, short bowel syndrome (SBS) rats underwent a 75% small bowel resection, and SBS-BBS rats underwent bowel resection and were treated with BBS given subcutaneously at a dose of 20 mug/kg, once daily, from postoperative day 3 through 14. Parameters of intestinal adaptation (bowel and mucosal weights, mucosal DNA and protein, villus height and crypt depth), enterocyte proliferation and enterocyte apoptosis were determined in jejunum and ileum on day 15 following operation. RT-PCR technique was used to determine Bax and Bcl-2 gene expression in ileal mucosa. Statistical analysis was performed using the non-parametric Kruskal-Wallis ANOVA test, with P less than 0.05 considered statistically significant. Treatment with BBS resulted in a significant increase in ileal bowel and mucosal weight, ileal mucosal DNA and protein, jejunal and ileal villus height, jejunal crypt depth, and jejunal and ileal proliferation index compared to SBS-animals. SBS rats showed a significant increase in Bax and Bcl-2 expression in ileum that was accompanied by a significant increase in cell apoptosis compared to sham animals. SBS-BBS rats demonstrated a significant decrease in Bax and Bcl-2 expression in ileum and a decrease in apoptotic index compared to SBS-animals. In conclusion, in a rat model of SBS, BBS enhances enterocyte turnover and stimulates structural intestinal adaptation. Decreased Bax expression may be responsible for the inhibitory effect of BBS on enterocyte apoptosis.

Congenital intestinal anomalies, neonatal short bowel syndrome, and prenatal/neonatal counseling

BACKGROUND

Short bowel syndrome (SBS) is a severe malabsorption caused by bowel loss. Congenital intestinal anomalies (CIA) detectable by prenatal ultrasound as jejunoileal atresia, meconium peritonitis, complicated meconium ileus, and fetal volvulus can be responsible for SBS.

AIMS

This study aims to investigate either frequency of SBS or the morbidity in CIA population during the first admission.

MATERIAL AND METHODS

Records of CIA treated from 1997 to 2003 were reviewed. The prenatal ultrasound findings were correlated with SBS. Student's t and chi(2) tests were performed to analyze epidemiological data, growth at discharge, sepsis, liver disease, catheter-related complications, motor developmental delay, and hospital stay in CIA with and without SBS.

RESULTS

Forty-four CIA: SBS developed in 43%, ranging from 83% in volvulus to 0% in complicated meconium ileus. Thirty-six prenatal diagnoses: a strong correlation with SBS was observed in isolated dilated bowel (58%). In SBS neonates, birth weight, gestational age, and growth at discharge were statistically lower, whereas sepsis, motor delay, and hospital stay were statistically higher.

CONCLUSIONS

Many neonates with CIA detectable by prenatal ultrasound develop SBS. Short bowel syndrome presents a significant higher morbidity. The counseling should stress the frequent association between CIA and SBS as well as the significant morbidity in SBS.

Advances in short bowel syndrome: an updated review

Short bowel syndrome (SBS) continues to be an important clinical problem due to its high mortality and morbidity as well as its devastating socioeconomic effects. The past 3 years have witnessed many advances in the investigation of this condition, with the aim of elucidating the cellular and molecular mechanisms of intestinal adaptation. Such information may provide opportunities to exploit various factors that act as growth agents for the remaining bowel mucosa and may suggest new therapeutic strategies to maintain gut integrity, eliminate dependence on total parenteral nutrition, and avoid the need for intestinal transplantation. This review summarizes current research on SBS over the last few years.

Oral insulin enhances intestinal regrowth following massive small bowel resection in rat

Experimental studies have suggested that insulin (INS) plays an important role in small intestinal growth and development. In the present study we investigated the effect of oral INS on structural intestinal adaptation and enterocyte proliferation and loss via apoptosis in a rat model of short bowel syndrome (SBS). Male Sprague-Dawley rats were divided into three experimental groups: sham rats underwent bowel transection, SBS rats underwent 75% small bowel resection, and SBS-INS rats underwent bowel resection and were treated with oral INS given in the drinking water from the 3rd to the 15th postoperative day. Parameters of intestinal adaptation (bowel and mucosal weight, mucosal DNA and protein, villous height, and crypt depth), enterocyte proliferation, and apoptosis were determined on day 15. SBS-INS rats demonstrated a significant increase (vs SBS rats) in jejunal and ileal overall bowel and mucosal weight, ileal mucosal DNA and protein, ileal villous height, and crypt depth. SBS-INS rats also showed an increased cell proliferation index in jejunum and ileum and decreased apoptotic index in jejunum compared to SBS animals. In conclusion, in a rat model of SBS, oral INS strongly enhances intestinal adaptation. Possible mechanisms may include increased cell proliferation and decreased enterocyte loss via apoptosis.

Parenteral arginine impairs intestinal adaptation following massive small bowel resection in a rat model

The nitric oxide precursor L-arginine (ARG) has been shown to influence intestinal structure and absorptive function. It is also well known that the route of administration modulates the effects of ARG. The present study evaluated the effects of parenteral ARG on structural intestinal adaptation, cell proliferation, and apoptosis in a rat model of short bowel syndrome (SBS). Male Sprague-Dawley rats were divided into three experimental groups: Sham rats underwent bowel transection and reanastomosis, SBS rats underwent a 75% small bowel resection, and SBS-ARG rats underwent a 75% small bowel resection and were treated with ARG given subcutaneously at a dose of 300 mug/kg, once daily, from days 3 to 14. Parameters of intestinal adaptation, enterocyte proliferation, and enterocyte apoptosis were determined on day 15 following operation. The SBS rats demonstrated a significant increase in jejunal and ileal bowel and mucosal weight, villus height and crypt depth, and cell proliferation index compared with the sham group. The SBS-ARG animals demonstrated lower ileal bowel and mucosal weights, jejunal mucosal DNA and ileal mucosal protein, and jejunal and ileal villus height and crypt depth compared with SBS animals. The SBS-ARG rats also had a lower cell proliferation index in both jejunum and ileum and a greater enterocyte apoptotic index in ileum compared with the SBS-untreated group. In conclusion, in a rat model of SBS, parenteral arginine inhibits structural intestinal adaptation. Decreased cell proliferation and increased apoptosis are the main mechanisms responsible for decreased cell mass.

Effect of subcutaneous insulin on intestinal adaptation in a rat model of short bowel syndrome

Insulin has been shown to influence intestinal structure and absorptive function. The purpose of the present study was to evaluate the effects of parenteral insulin on structural intestinal adaptation, cell proliferation, and apoptosis in a rat model of short bowel syndrome (SBS). Male Sprague-Dawley rats were divided into three experimental groups: sham rats underwent bowel transection and reanastomosis, SBS rats underwent a 75% small bowel resection, and SBS-INS rats underwent a 75% small bowel resection and were treated with insulin given subcutaneously at a dose of 1 U/kg, twice daily, from day 3 through day 14. Parameters of intestinal adaptation, enterocyte proliferation, and enterocyte apoptosis were determined on day 15 following operation. SBS rats demonstrated a significant increase in jejunal and ileal bowel and mucosal weight, villus height and crypt depth, and cell proliferation index compared with the sham group. SBS-INS animals demonstrated higher jejunal and ileal bowel and mucosal weights, jejunal and ileal mucosal DNA and protein, and jejunal and ileal crypt depth compared with SBS animals. SBS-INS rats also had a greater cell proliferation index in both jejunum and ileum and a trend toward a decrease in enterocyte apoptotic index in jejunum and ileum compared with the SBS untreated group. In conclusion, parenteral insulin stimulates structural intestinal adaptation in a rat model of SBS. Increased cell proliferation is the main mechanism responsible for increased cell mass.

Impaired absorption of marked oligopeptide Glycine-I Tyrosine-Glycine after successful autologous-allotopic ileal mucosa transplantation in beagles

PURPOSE

After establishing a method for ileal mucosa transplantation in an animal model, the authors investigated the absorptive capacity for oligopeptides of the transplanted mucosa.

METHODS

In 14 beagle dogs the authors transplanted ileal mucosa in a vascularized demucosed segment of the transverse colon. The colonic wall-ileal mucosa complex then was integrated in the ileal continuity. Six animals were lost owing to operative complications. Absorptive capacity for oligopeptides was measured in the remaining 8 animals with the iodine 131 (131I)-marked tripeptide glycine-tyrosine-glycine before and 4 weeks after transplantation. The results were compared and analyzed with the Student's t test for matched pairs. Blood concentrations of the marked tripeptide with P value less than .05 were considered as a significant reduction in the absorptive capacity of the transplanted ileal mucosa. After fixation with glutaraldehyd graft, uptake of the colonic wall-ileal mucosa complex was evaluated histologically in 8 animals.

RESULTS

In all 8 animals, a 100% graft uptake was verified in all sections. Fifteen minutes after application of 15 MBc Glycine-131I-Tyrosine-Glycine there was no significant difference in the absorption between normal and transplanted ileal mucosa. After 30 minutes, the absorption of the transplanted ileal mucosa showed a tendency (P < .1) for an impaired uptake of the marked tripeptide. However, 60 minutes after application the difference in the absorptive capacity of the transplanted ileal mucosa was significant (P < .05).

CONCLUSIONS

Autologous allotopic ileal mucosa transplantation is feasible; however, an impaired absorption of oligopeptides of the transplanted mucosa 4 weeks after transplantation could be observed.

Absorption of D(+)-xylose, cobalamin, and folic acid after autologic-allotopic ileum mucosa transplantation in beagles

BACKGROUND/PURPOSE

Ileum mucosa transplantation in a demucosed colon coat was developed as a new method for small bowel elongation. In an animal model, the authors investigated the absorptive capacity of the transplanted mucosa for D(+)-xylose, cobalamin (vitamin B12), and folic acid.

METHODS

Ileum mucosa was transplanted in a vascularized demucosed segment of transverse colon in 18 beagle dogs. The colon coat-ileum mucosa complex then was integrated in the ileal continuity. Absorptive capacity for D(+)-xylose, cobalamin, and folic acid was measured before and 4 weeks after transplantation. The results were compared and analyzed with the Students' t test for matched pairs. All determined blood values with P values less than.05 were considered to show a significant reduction in the absorptive capacity of the transplanted ileum mucosa.

RESULTS

Fifteen minutes after application there was no significant difference in the absorption of D(+)-Xylose and cobalamin between normal and transplanted ileum mucosa (P >.1). Absorption of folic acid in the transplanted segment was lower but not significant (P <.1). After 30 minutes D(+)-xylose and cobalamin again showed no difference between the absorptive capacity of normal and transplanted ileum mucosa (P >.1), whereas folic acid continued with the tendency toward an impaired absorption (P <.1). However, after 60 minutes, the difference of the absorptive capacity of the transplanted ileum mucosa was significant (P <.05) for folic acid. D(+)-xylose showed a tendency for an impaired uptake (P <.1), whereas absorption of cobalamin did not differ significantly after transplantation (P >.1).

CONCLUSIONS

Experimental autologic-allotopic ileum mucosa transplantation is a feasible new method for small bowel elongation in an animal model. Examination of the absorptive capacity of the transplanted ileum mucosa showed a normal uptake for cobalamin, while there was an impaired absorption of D(+)-xylose and folic acid.

Histologic changes in neuronal innervation of the ileum mucosa after autologic-allotopic ileum mucosa transplantation

INTRODUCTION

After successful experimental autologic-allotopic ileum mucosa transplantation, we investigated the remodeling of the transplanted submucous and mucous plexus, which is essential for the motility of the created colon coat-ileum mucosa complex.

METHOD

In 8 beagles we transplanted ileum mucosa in a demucosed vascularized transverse colon segment, which was reanastomosed with the small bowel immediately after transplantation. Four weeks later the animals were sacrificed and histology specimens taken from the anastomosis site of the colon coat-ileum mucosa complex, allowed comparison between transplanted and normal mucosa in the same section. After fixation in 4% formaldehyde and PBS the samples were embedded in paraffin and 7 micro m sections were prepared. The distribution of nerve fibers and submucous ganglia were examined in dewaxed sections, using antisera against protein gene product (PGP9.5), a general neuronal marker.

RESULTS

The submucosal ganglia were prominent in all samples but they were smaller and the submucous nerve cells within the ganglia were less numerous compared to the controls. The innervation of the transplanted ileum mucosa was reduced as the number of nerve fibers in the mucosal villi was decreased. Besides these neuromorphologic changes the transplanted mucosa showed a slightly higher rate of shortened villi compared to normal ileum mucosa.

CONCLUSIONS

After ileum mucosa transplantation the submucosal ganglia are smaller and less numerous. Furthermore there is a considerable loss of nerve fibers in the mucosal layer. Additionally a loss of microvilli in the transplanted ileum mucosa was found. Whether these findings represent a state of remodeling or a slow atrophy of the enteric nervous system in the transplanted areas is currently under investigation.

Classification, epidemiology and aetiology

Intestinal failure and its most important cause, short-bowel syndrome (SBS), are rare clinical entities leading to a vast complex of symptoms and complications with significant morbidity and mortality. Both conditions occur as the result of a massive reduction in enteral nutrient absorptive capacity. Disease manifestation is based on aetiological and anatomical characteristics such as remaining intestinal length and the presence of a functionally intact colon. Congenital and perinatal conditions, for example, intestinal atresia, necrotizing enterocolitis (NEC) and intestinal volvulus are the most important causes in children. The aetiology in adults is based on diseases inducing loss of intestinal function or loss of intestinal surface area after extensive surgical resections. The most frequent causes are mesenteric infarction, radiation enteritis and Crohn's disease. Knowledge of the epidemiology of intestinal failure and SBS is limited, being mainly based on the extrapolated figures of home parenteral nutrition centres and single-centre studies. At present, the incidence of SBS is estimated to be 2-5 per million.

Mortality and economics in short bowel syndrome

The incidence of patients with short-bowel syndrome (SBS) has increased over the years due to progress of intensive care medicine and parenteral nutrition techniques. These techniques have significantly improved the prognosis of neonates, children and adults who have lost major parts of their intestinal tract. Long-term survival is possible and does not depend primarily on the length of the remaining bowel but on complications such as parenteral nutrition-associated cholestasis, recurrent septicaemia, central venous catheter infections, and the motility of the remaining intestine. Thus, the overall related mortality in infants with SBS ranges from 15 to 25%, and in adults from 15 to 47%, depending on the age of the patients, the underlying disease, and the duration on total parenteral nutrition. Home parenteral nutrition (HPN) significantly decreases the complication rate and improves the psychological situation of the patient. Additionally, HPN reduces in-hospital cost significantly. Nevertheless, the annual costs/patient are between $100000 and $150000. The mortality rate of SBS patients on HPN is about 30% after 5 years, which is still lower than the 5-year survival rate of intestinal grafts, and it is about equal to patients' survival after intestinal transplantation. However, the overall costs of a successful intestinal transplantation are already lower after 2 years when compared with the cost of a prolonged HPN programme.

Low-fat diet impairs postresection intestinal adaptation in a rat model of short bowel syndrome

BACKGROUND

Low-fat diets (LFD) are utilized frequently in patients with short bowel syndrome (SBS). The purpose of this study was to investigate the effects of LFD on intestinal adaptation, enterocyte proliferation, and enterocyte cell death in a rat model of SBS.

METHODS

Adult male Sprague-Dawley rats were divided into 3 experimental groups: Sham-NC rats underwent bowel transection and reanastomosis and were fed normal chow (NC), SBS-NC rats underwent 75% small bowel resection and were fed NC, and SBS-rats were fed a low-fat diet (SBS-LFD). Parameters of intestinal adaptation, enterocyte proliferation, and enterocyte apoptosis were determined on day 14 after operation.

RESULTS

SBS-NC rats showed a significant increase (v Sham-NC) in jejunal and ileal bowel and mucosal weight, mucosal DNA and protein, villus height, and crypt depth. A significant 67% increase in crypt cell proliferation rate and 265% increase in villus enterocyte apoptosis was seen in the ileum of SBS-NC rats compared with control animals (P <.05). SBS-LFD animals showed lower ileal mucosal weight (29%; P <.05), jejunal crypt depth (20%; P <.05), and ileal villus height (21%; P <.05). A significant decrease in villus apoptosis in jejunum (74%; P <.05) and ileum (67%; P <.05) and a decrease in cell proliferation in ileum (35%; P <.05) was seen also after exposure to LFD compared with SBS-NC.

CONCLUSIONS

In a rat model of SBS, early LFD appears to inhibit parameters of intestinal adaptation. A possible mechanisms for this effect may be decreased cell proliferation. Decreased enterocyte loss via apoptosis, found in this study, may reflect a reduced number of enterocyte.

Effect of a high fat diet on lipid absorption and fatty acid transport in a rat model of short bowel syndrome

Long chain fatty acids (LCFAs) appear to be powerful stimulants for small bowel adaptation in patients with short bowel syndrome (SBS). However, the dietary lipid content may alter intestinal lipid transport. The aim of this study was to investigate the effects of a high fat diet (HFD) on in vivo lipid absorption and molecular and cellular mechanisms of LCFAs uptake by the remaining bowel. Male Sprague-Dawley rats (240-280) were randomly assigned to one of three groups: sham rats fed normal chow (sham-NC), SBS rats fed NC (SBS-NC) and SBS rats fed HFD (SBS-HFD). SBS rats underwent a 75% small bowel resection. Rats were sacrificed on day 3 or 14. Body weight, fat intake and fat clearance (total fecal fat) were measured twice a week. Fat absorbability was calculated as intake minus clearance and was expressed as percent of intake. Total RNA from the mucosa of duodenum, jejunum and ileum was extracted using TRIZOL Reagent. Northern blot analysis was performed to determine FAT/CD36 mRNA levels. Enterocyte LCFA transport was measured on day 14. LCFA uptake was determined by measuring cellular [3H]-oleate uptake over time (4-120 s). Mean (+/-SE) FAT/CD36 mRNA levels and oleate uptake kinetic parameters were analyzed using ANOVA. Fat absorbability diminished after bowel resection, suggesting fat malabsorption. Remaining bowel in SBS-NC rats responded by an increase in FAT/CD36 mRNA levels in the duodenum and ileum on day 3, and the duodenum and jejunum on day 14 compared to sham-NC animals, and was accompanied by an increase in enterocyte LCFA transport in all segments. Exposure to a HFD for 14 days resulted in significantly increased fat absorbability after 3 days compared to SBS-NC rats. However, FAT/CD36 mRNA levels (vs. SBS-NC) decreased in all segments on day 3. On day 14, FAT/CD36 mRNA levels were decreased in the duodenum and ileum and were accompanied by reduced oleate uptake by isolated enterocytes in the ileum (vs. SBS-NC). In a rat model of SBS, early high fat diet increased lipid absorptive capacity of the intestinal remnant as seen by increased fat absorbability. The main mechanisms of this effect may be an acceleration of structural intestinal adaptation resulting in an increased number of enterocytes. However, at molecular and cellular levels HFD decreased mucosal FAT/CD36 mRNA levels and oleic acid uptake by isolated enterocytes.

Endotoxemia inhibits intestinal adaptation in a rat model of short bowel syndrome

Sepsis is commonly associated with or complicates short bowel syndrome (SBS). The purpose of the present study was to investigate the effects of endotoxemia on intestinal adaptation in a rat model of SBS. Male Sprague-Dawley rats were divided into three experimental groups: Sham rats underwent bowel transection and re-anastomosis, SBS rats underwent 75% small bowel resection, and SBS-LPS rats underwent bowel resection and were given lipopolysaccharide. Bowel weight, organ weights, and parameters of intestinal adaptation (bowel and mucosal weights, mucosal DNA and protein, villus height, and crypt depth) were determined on day 15 following operation. The results of this study demonstrate that SBS rats showed a significant increase (vs. Sham) in jejunal and ileal bowel and mucosal weight, mucosal DNA and protein, villus height, and crypt depth. SBS-LPS animals demonstrated lower (vs. SBS rats) final body weight (215 +/- 7 vs. 287 +/- 10 g, P < 0.05), overall weight in duodenum (98+/- 2 vs. 119 +/-5 mg/cm, P < 0.05) and jejunum (144 +/- 9 vs. 189 +/- 16 mg/cm, P < 0.05), mucosal weight in jejunum (54 +/- 5 vs. 69 +/- 5 mg/cm, P < 0.05) and ileum (31 +/- 2 vs. 37 +/- 3 mg/cm, P < 0.05), mucosal DNA in jejunum (89 +/- 11 vs. 120 +/- 11 microg/cm, P < 0.05) and ileum (46 +/- 6 vs. 61 +/- 4 microg/cm, P < 0.05), jejunal crypt depth (152 +/- 19 vs. 189 +/- 12 microm, P < 0.05), and ileal villus height (405 +/- 63 vs. 515 +/- 30 pm, P < 0.05). In addition, the SBS group had no late (second week) mortality, whereas the SBS-LPS group had an 17% late mortality rate. In conclusion, in a rat model of SBS-LPS, endotoxemia appears to inhibit structural intestinal adaptation and increase mortality.

Update on management and treatment of short gut

Management of patients with short-bowel syndrome represents a formidable challenge. Aggressive treatment including nutritional care and anticipation of potential complications and rapid treatment of complications enhance outcome. New therapies offer the promise of significantly improving morbidity and mortality. Intestinal transplant is appropriate for infants who would otherwise die from liver disease, recurrent sepsis, or lack of venous access.

The management of patients with the short bowel syndrome

The surgeon is invariably the primary specialist involved in managing patients with short bowel syndrome. Because of this they will play an important role in co-ordinating the management of these patients. The principal aims at the initial surgery are to preserve life, then to preserve gut length, and maintain its continuity. In the immediate postoperative period, there needs to be a balance between keeping the patient alive through the use of TPN and antisecretory agents and promoting gut adaptation with the use of oral nutrition. If the gut fails to adapt during this period, then the patient may require therapy with more specific agents to promote gut adaptation such as growth factors and glutamine. If following this, the patient still has a short gut syndrome, then the principal options remain either long term TPN, or intestinal transplantation which remains a difficult and challenging procedure with a high mortality and morbidity due to rejection.

Virtue ethics in a pluralistic world

The practice of pediatric surgery is at the crossroads of 2 specialties, pediatrics and surgery. At that vantage point, many ethical dilemmas can be seen. It is important for the pediatric surgeon to understand the special place of ethics in the care of children and how that care is influenced by society. The purpose of this report is to introduce the perspective of virtue ethics as an avenue to problem solving in ethical dilemmas in pediatric surgery. Virtue ethics relies more on the physician-focused view of character and ideal behavior as opposed to more patient-based rules of action. This ethical theory must be placed on the background of our changing society with an increasing plurality of values. The medical community of pediatric surgery must remain involved in the dialogue concerning these dilemmas in the care of children.

Parenteral nutrition-associated cholestasis

Cholestasis is a major complication that occurs frequently in patients with the short bowel syndrome and accounts for the majority of morbidity and mortality in this group of patients. The exact cause of this condition is not known and the etiology is likely multifactorial. Many new mechanistic insights into this disease are discussed and have paved the way for future investigation. For now, prompt recognition, early initiation of enteral feeding, prevention of overfeeding with parenteral nutrition, and agents that induce bile flow may be useful to prevent this catastrophic morbidity.

Short bowel syndrome in infants and children: an overview

Short bowel syndrome is a spectrum of malnutrition resulting from inadequate bowel length. In infant and pediatric patients, the most common causes are necrotizing enterocolitis, abdominal wall defects, jejunal ileal atresia, and mid gut volvulus. There appear to be regional variations in etiology. Since the publication of Wilmore's classic monograph in 1972, there have been significant improvements in monitoring and nutritional support. In the modern era, survival rate ranges from 80% to 94%, and the presence or absence the ileal cecal valve appears to not impact on mortality rate, but does significantly affect the length of time on total parenteral nutrition TPN. The most common morbidities remain sepsis, both central line related and bacterial overgrowth, and TPN cholestasis. Long-term recovery of these children often is remarkably normal, but there is a 10% to 15% incidence of neurologic and developmental defects. The clinical and ethical considerations around the care of infants with 20 to 40 cm of residual bowel remains controversial, as does the place of intestinal transplantation, especially in patients developing gut failure in infancy. Perioperative surgical decision making plays a critical role in the long-term outcome of these patients. This chapter presents an overview of the current status of care and outcome in this difficult population; these topics are further expanded in subsequent chapters.