Interposition of a Reversed Jejunal Segment Enhances Intestinal Adaptation in Short Bowel Syndrome: An Experimental Study on Pigs

Segmental reversal of the distal small intestine in a short bowel syndrome model in piglets showed detrimental effect on weight gain

Background

To investigate the effects of a reversed segment of the distal small intestine to improve weight gain in an experimental short bowel syndrome (SBS) model in piglets.

Methods

Twenty-four piglets underwent resection of 70% of the distal small intestine. In half of the animals a conventional anastomosis was performed, and in the other half, the distal 25 cm of the remnant jejunum was reversed before the intestinal continuity was recreated. Weight was measured daily until day 28, where the animals were euthanized. Glucagon-Like Peptide-2 (GLP-2) and Glucose-dependent Insulinotropic Peptide (GIP) was measured pre- and postoperatively at day 28.

Results

The group with reversal of small intestine had a significant lower weight gain at 5.26 ± 3.39 kg (mean ± SD) compared to the control group with 11.14 ± 3.83 kg (p < 0.05). In the control group greater villus height and crypt depth was found distally, and greater muscular thickness was found proximally in the intervention group. GLP-2 and GIP levels increased significantly in the control group.

Conclusions

Treatment of short bowel syndrome with a reversed jejunal segment of 25 cm had a detrimental effect on the weight gain.

Autologous Intestinal Reconstruction Surgery in Short Bowel Syndrome: Which, When, and Why

Short bowel syndrome (SBS), secondary to any natural loss or after any extensive bowel resection for congenital malformations or acquired disease, is the most common cause of intestinal failure in children. Extensive introduction of parenteral nutrition (PN) has dramatically changed the outcome of these patients, allowing for long-term survival. The main goal in children with SBS remains to be increasing enteral tolerance and weaning from PN support. Post resection intestinal adaptation allows for achievement of enteral autonomy in a subset of these patients, but the inability to progress in enteral tolerance exposes others to long-term complications of PN. Autologous intestinal reconstruction surgery (AIRS) can facilitate the fulfilment of enteral autonomy, maximizing the absorptive potential of the remaining gut. All the different intestinal reconstruction techniques, from simple procedures like tapering, reversed segments, and colon interposition, to more complex lengthening procedures (LILT: longitudinal intestinal lengthening and tailoring, STEP: serial transverse enteroplasty, and SILT: spiral intestinal lengthening and tailoring) and techniques designed for peculiar problems like controlled intestinal tissue expansion or duodenal lengthening are presented. AIRS indications, clinical applications, and results reported in the literature are reviewed.

Dietary Tryptophan Supplementation Alters Fat and Glucose Metabolism in a Low-Birthweight Piglet Model

Low birthweight (LBW) is associated with metabolic complications, such as glucose and lipid metabolism disturbances in early life. The objective of this study was to assess: (1) the effect of dietary tryptophan (Trp) on glucose and fat metabolism in an LBW piglet model, and (2) the role peripheral 5-hydroxytryptamine type 3 (5HT3) receptors in regulating the feeding behavior in LBW piglets fed with Trp-supplemented diets. Seven-day-old piglets were assigned to 4 treatments: normal birthweight-0%Trp (NBW-T0), LBW-0%Trp (LBW-T0), LBW-0.4%Trp (LBW-T0.4), and LBW-0.8%Trp (LBW-T0.8) for 3 weeks. Compared to LBW-T0, the blood glucose was decreased in LBW-T0.8 at 60 min following the meal test, and the triglycerides were lower in LBW-T0.4 and LBW-T0.8. Relative to LBW-T0, LBW-T0.8 had a lower transcript and protein abundance of hepatic glucose transporter-2, a higher mRNA abundance of glucokinase, and a lower transcript of phosphoenolpyruvate carboxykinase. LBW-T0.4 tended to have a lower protein abundance of sodium-glucose co-transporter 1 in the jejunum. In comparison with LBW-T0, LBW-T0.4 and LBW-T0.8 had a lower transcript of hepatic acetyl-CoA carboxylase, and LBW-T0.4 had a higher transcript of 3-hydroxyacyl-CoA dehydrogenase. Blocking 5-HT3 receptors with ondansetron reduced the feed intake in all groups, with a transient effect on LBW-T0, but more persistent effect on LBW-T0.8 and NBW-T0. In conclusion, Trp supplementation reduced the hepatic lipogenesis and gluconeogenesis, but increased the glycolysis in LBW piglets. Peripheral serotonin is likely involved in the regulation of feeding behavior, particularly in LBW piglets fed diets supplemented with a higher dose of Trp.

Segmental reversal of distal small intestine in short bowel syndrome: a study on the influence on postoperative weight and intestinal topography in piglets

PURPOSE

The objective of the present study was to investigate the effect of segmental reversal of the distal 20 cm of the small intestine in piglets with induced SBS compared to controls with SBS alone. Primary endpoint was postoperative weight change over a period of 1 month. Secondary endpoints were the influence on cell proliferation and mucosal architecture shown by histological analysis.

METHODS

Sixteen piglets underwent a 60% resection of the distal small intestine and were randomized into two groups. Group 1 short bowel syndrome alone (SBS) (n = 8) and group 2 with reversal of a distal small intestinal segment (SBS-RS) (n = 8). Body weight was measured daily and the pigs were euthanized after 1 month. Crypt depths, villus heights and muscle layers thicknesses were measured. For the evaluation of microvilli of the brush border of the epithelium and cell proliferation, immunohistochemical staining with Villin and Ki-67 was performed.

RESULTS

No statistically significant differences were observed concerning weight gain. Mean ± SD weight gain was 2.31 ± 2.85 kg for SBS-RS and 2.03 ± 1.27 kg for SBS (p = 0.8). In the proximal jejunal segment a significant increase in villus heights was found in the SBS group and increase in the thickness of the circular and longitudinal muscle layers in the SBS-RS group. In the distal ileal segment the longitudinal muscle layer thicknesses were increased in the SBS group. Otherwise, no significant changes were found.

CONCLUSION

Reversal of a 20-cm distal segment showed no effect on weight gain, but there were some significant histological changes of unknown clinical significance.

Success of serial transverse enteroplasty in an adult with extreme short bowel syndrome: a case report

Since its introduction as an alternative intestinal lengthening technique, serial transverse enteroplasty has been increasingly used as the surgical treatment of choice for children with refractory short bowel syndrome, but there have been few reports about the adult patients. This report describes the case of a 71-year-old man with a short bowel after distal gastrectomy with Billroth II reconstruction for gastric cancer, followed by extensive intestinal resection. The serial transverse enteroplasty operation was performed and lengthened the small intestine from 49 to 67 cm. The patient tolerated the procedure well and weaned off total parenteral nutrition. Liver function also improved. This case shows that the serial transverse enteroplasty procedure increases intestinal length. This procedure should be considered a surgical option for adult patients with extreme short bowel syndrome.

Significance of the Extent of Intestinal Resection on the Outcome of a Short-bowel Syndrome in a Porcine Model

AIM OF THE STUDY

Insufficient data are available to determine the most suitable extent of intestinal resection required to induce short-bowel syndrome (SBS) in pigs. This study aimed to compare the three main SBS-models published.

METHODS

A 75%, 90%, or 100% mid-intestinal resection was performed in groups of n = 5 pigs each. Clinical (body weight, stool consistency) and biochemical (serum eletrolytes, citrulline, albumin, prealbumin, and transferrin) parameters were determined daily, functional (D-xylose resorption) and histological (intestinal villus length) parameters were determined after 2 weeks. A t-test and ANOVA were used for statistical analysis.

RESULTS

Only in the 100% group, we observed a persistent weight loss (13.6 ± 3.8%) and diarrhea, as well as a decrease in prealbumin-levels (41%) and transferrin levels (33%). Serum electrolytes remained stable in all groups during the observation period. Citrulline stabilized at different levels (100% group 13.9 ± 1.0 μmol/L; 90% group 18.8 ± 1.0 μmol/L; 75% group 26.3 ± 1.4 μmol/L; all p < .05). D-xylose resorption was lowest in the 100%, followed by 90% and 75% group (100% group 32.8 ± 4.9 mg/L; 90% group 50.0 ± 19.6 mg/L; 75% group 57.8 ± 8.8 mg/L; p = .393). Intestinal villus length decreased in all groups (100% group 11.0%; 90% group 14.0%; 75% group 19.1%).

CONCLUSIONS

75% intestinal resection is less suitable as an SBS model, as animals tend to recover remarkably. The 90% model is suitable for longer-term studies, as animals might survive longer due to partial compensation. Due to severe nutritional, biochemical, and physiological derangements, the 100% model can only be used for acute experiments and those immediately followed by small bowel transplantation.

Animal models of gastrointestinal and liver diseases. Animal models of infant short bowel syndrome: translational relevance and challenges

Intestinal failure (IF), due to short bowel syndrome (SBS), results from surgical resection of a major portion of the intestine, leading to reduced nutrient absorption and need for parenteral nutrition (PN). The incidence is highest in infants and relates to preterm birth, necrotizing enterocolitis, atresia, gastroschisis, volvulus, and aganglionosis. Patient outcomes have improved, but there is a need to develop new therapies for SBS and to understand intestinal adaptation after different diseases, resection types, and nutritional and pharmacological interventions. Animal studies are needed to carefully evaluate the cellular mechanisms, safety, and translational relevance of new procedures. Distal intestinal resection, without a functioning colon, results in the most severe complications and adaptation may depend on the age at resection (preterm, term, young, adult). Clinically relevant therapies have recently been suggested from studies in preterm and term PN-dependent SBS piglets, with or without a functional colon. Studies in rats and mice have specifically addressed the fundamental physiological processes underlying adaptation at the cellular level, such as regulation of mucosal proliferation, apoptosis, transport, and digestive enzyme expression, and easily allow exogenous or genetic manipulation of growth factors and their receptors (e.g., glucagon-like peptide 2, growth hormone, insulin-like growth factor 1, epidermal growth factor, keratinocyte growth factor). The greater size of rats, and especially young pigs, is an advantage for testing surgical procedures and nutritional interventions (e.g., PN, milk diets, long-/short-chain lipids, pre- and probiotics). Conversely, newborn pigs (preterm or term) and weanling rats provide better insights into the developmental aspects of treatment for SBS in infants owing to their immature intestines. The review shows that a balance among practical, economical, experimental, and ethical constraints will determine the choice of SBS model for each clinical or basic research question.

Short bowel syndrome in children: surgical and medical perspectives

The main cause of intestinal failure in children is due to short bowel syndrome (SBS) resulting from congenital or acquired intestinal lesions. From the first lengthening procedure introduced by Bianchi, the last three decades have seen lengthening procedures established as fundamental components of multidisciplinary intestinal rehabilitation programs. Debate on indications and timing of the procedures is still open leaving SBS surgical treatment a great challenge. However, enteral autonomy is possible only with an individualized approach remembering that each SBS patient is unique. Current literature on autologous gastrointestinal reconstruction technique was reviewed aiming to assess a comprehensive pathway in SBS non-transplant management.

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.

Endogenous growth hormone and insulin after interposition of a reversed jejunal segment in short bowel syndrome. An experimental study on pigs

BACKGROUND

Interposition of a reversed jejunal loop in short bowel sydrome has previously been investigated in human along with animal models and seemed able to facilitate intestinal adaptation. However, it is unclear if growth hormone and insulin, well known for their implication in short bowel pathophysiology, intervene on this effect.

FINDINGS

Porcine models were randomly allocated to two cohorts: (1) short bowel (SB) group (n = 8) and (2) short bowel reverse jejunal segment (SB-RS) group (n = 8). Amongst other parameters serum growth hormone and insulin were measured at baseline, as well as on postoperative day 30 and 60.

CONCLUSION

Both endogenous hormones failed to demonstrate significant difference in respect to potential direct effect to mechanisms of enhanced intestinal adaptation in reversed group.