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

ESPEN guideline on chronic intestinal failure in adults - Update 2023

BACKGROUND & AIMS

In 2016, ESPEN published the guideline for Chronic Intestinal Failure (CIF) in adults. An updated version of ESPEN guidelines on CIF due to benign disease in adults was devised in order to incorporate new evidence since the publication of the previous ESPEN guidelines.

METHODS

The grading system of the Scottish Intercollegiate Guidelines Network (SIGN) was used to grade the literature. Recommendations were graded according to the levels of evidence available as A (strong), B (conditional), 0 (weak) and Good practice points (GPP). The recommendations of the 2016 guideline (graded using the GRADE system) which were still valid, because no studies supporting an update were retrieved, were reworded and re-graded accordingly.

RESULTS

The recommendations of the 2016 guideline were reviewed, particularly focusing on definitions, and new chapters were included to devise recommendations on IF centers, chronic enterocutaneous fistulas, costs of IF, caring for CIF patients during pregnancy, transition of patients from pediatric to adult centers. The new guideline consist of 149 recommendations and 16 statements which were voted for consensus by ESPEN members, online in July 2022 and at conference during the annual Congress in September 2022. The Grade of recommendation is GPP for 96 (64.4%) of the recommendations, 0 for 29 (19.5%), B for 19 (12.7%), and A for only five (3.4%). The grade of consensus is "strong consensus" for 148 (99.3%) and "consensus" for one (0.7%) recommendation. The grade of consensus for the statements is "strong consensus" for 14 (87.5%) and "consensus" for two (12.5%).

CONCLUSIONS

It is confirmed that CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for the underlying gastrointestinal disease and to provide HPN support. Most of the recommendations were graded as GPP, but almost all received a strong consensus.

Intestinal failure among adults and children: Similarities and differences

Intestinal failure (IF) is a complex medical condition that is caused by a constellation of disorders, resulting in the gut's inability to adequately absorb fluids and nutrients to sustain hydration, growth, and survival, thereby requiring the use of parenteral fluid and/or nutrition. Significant advancements in intestinal rehabilitation have resulted in improved survival rates for individuals with IF. There are distinct differences, however, related to etiology, adaptive potential and complications, and medical and surgical management when comparing children with adults. The purpose of this review is to contrast the similarities and differences between these two distinct groups and provide insight for future directions, as a growing population of pediatric patients will cross into the adult world for IF management.

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.

State-of-the-art colorectal disease: conservative surgical management of intestinal failure in adults

PURPOSE

Intestinal failure (IF) is defined by the reduction of gut function under the minimum necessary for adequate absorption of macronutrients and/or electrolytes, requiring home parenteral nutrition (HPN) to maintain health and/or growth. Among the different causes of IF, short bowel syndrome (SBS) is one of the main causes of IF in adults. Management of IF and SBS is complex and requires a multidisciplinary approach. The aim of this study was to review the place and the modalities of conservative surgical procedures performed for IF in adults.

RESULTS-CONCLUSION

HPN has drastically modified the poor prognosis of these patients, leading to an overall survival around 70-75% at 5 years in patients without cancer. However, HPN is associated with life-threatening long-term complications, including liver failure and catheter-related complications, main causes of deaths for these patients. Surgery can be proposed, in order to try to reduce SBS consequences with either conservative or non-conservative procedures. Simple bowel continuity restoration should be performed as often as possible in order to wean or at least to reduce HPN. Lengthening procedures are proposed to increase the absorption surface of the remnant bowel. These procedures can be only performed on a dilated small bowel. The slowing transit time procedure is represented by segmental reversal of the small bowel. Intestinal transplantation is the last surgical option for patients with IF but is still today associated with high mortality and failure rates. Thus, conservative procedures have a major role in the surgical armentarium for patients with IF.

New insights into intestinal failure-associated liver disease in adults: A comprehensive review of the literature

Intestinal failure-associated liver disease (IFALD) remains one of the most common and serious complications of parenteral nutrition (PN), causing a wide spectrum of hepatic manifestations from steatosis and mild cholestasis to portal hypertension and end-stage liver failure. The prevalence of IFALD depends on the diagnostic criteria and ranges from 4.3% to 65%. Moreover, many factors are shown to contribute to its development, including nutrient deficiencies, toxicity of PN, infections, and alterations of bile acid metabolism and gut microbiota. Prevention and management of IFALD aim at ameliorating or eliminating the risk factors associated with IFALD. The use of PN formulations with a lower ratio omega-6-to-omega-3 polyunsaturated fatty acids, cycle PN, optimization of enteral stimulation and prevention and early treatment of infections constitute the main therapeutic targets. However, failure of improvement and severe IFALD with end-stage liver failure should be considered as the indications of intestinal transplantation. The aim of this review is to provide an update of the epidemiology, pathophysiology, and diagnosis of IFALD in the adult population as well as to present a clinical approach of the therapeutic strategies of IFALD and present novel therapeutic targets.

Reconnection surgery in adult post-operative short bowel syndrome < 100 cm: is colonic continuity sufficient to achieve enteral autonomy without autologous gastrointestinal reconstruction? Report from a single center and systematic review of literature

A systematic bibliographic research concerning patients operated on for SBS was performed: inclusion criteria were adult age, reconnection surgery and SBS < 100 cm. Autologous gastrointestinal reconstruction represented an exclusion criteria. The outcomes of interest were the rate of total parenteral nutrition (TPN) independence and the length of follow-up (minimum 1 year) after surgery. We reviewed our experience from 2003 to 2013 with minimum 1-year follow-up, dealing with reconnection surgery in 13 adults affected by < 100 cm SBS after massive small bowel resection: autologous gastrointestinal reconstruction was not feasible. Three (out of 5168 screened papers) non randomized controlled trials with 116 adult patients were analysed showing weaning from TPN (40%, 50% and 90% respectively) after reconnection surgery without autologous gastrointestinal reconstruction. Among our 13 adults, mean age was 54.1 years (53.8 % ASA III): 69.2 % had a high stomal output (> 500 cc/day) and TPN dependence was 100%. We performed a jejuno-colonic anastomosis (SBS type II) in 53.8%, in 46.1% of cases without ileo-cecal valve, leaving a mean residual small bowel length of 75.7 cm. In-hospital mortality was 0%. After a minimum period of 1 year of intestinal rehabilitation, all our patients (100%) went back to oral intake and 69.2% were off TPN (9 patients). No one was listed for transplantation. A residual small bowel length of minimum 75 cm, even if reconnected to part of the colon, seems able to produce a TPN independence without autologous gastrointestinal reconstruction after a minimum period of 1 year of intestinal rehabilitation.

Short bowel syndrome in children and adults: from rehabilitation to transplantation

Short bowel syndrome (SBS) is a dramatic clinical condition in both children and adults; the residual bowel length is not sufficient to avoid intestinal failure, with subsequent malnutrition and growth retardation, and intravenous support is required to provide the nutrients normally coming from the intestine. Apart from the primary disease, the medical status can be worsened by complications of intestinal failure: if there are irreversible, the prognosis is poor unless a successful intestinal rehabilitation is achieved. Areas covered: The rescue of the remnant small bowel requires a multidisciplinary expertise to achieve digestive autonomy. The use of intestinal trophic factors has shown encouraging results in improving the intestinal adaptation process. Whenever the residual bowel length is inadequate, in a well-selected population weaning parenteral nutrition (PN) off could be attempted by surgery through lengthening procedures. A further subset of patients, with total and irreversible intestinal failure and severe complications on PN, may have an indication to intestinal transplantation. This procedure is still affected by poor long-term results. Expert commentary: Novel approaches developed through a multidisciplinary team work, such as manipulation of microbiota or tissue bioengineering, should be added to current therapies to treat successfully SBS.

Intestinal failure in adults: Recommendations from the ESPEN expert groups

BACKGROUND & AIMS

Intestinal failure (IF) is defined as "the reduction of gut function below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth". Functionally, it may be classified as type I acute intestinal failure (AIF), type II prolonged AIF and type III chronic intestinal failure (CIF) The ESPEN Workshop on IF was held in Bologna, Italy, on 15-16 October 2017 and the aims of this document were to highlight the current state of the art and future directions for research in IF.

METHODS

This paper represents the opinion of experts in the field, based on current evidence. It is not a formal review, but encompasses the current evidence, with emphasis on epidemiology, classification, diagnosis and management.

RESULTS

IF is the rarest form of organ failure and can result from a variety of conditions that affect gastrointestinal anatomy and function adversely. Assessment, diagnosis, and short and long-term management involves a multidisciplinary team with diverse expertise in the field that aims to reduce complications, increase life expectancy and improve quality of life in patients.

CONCLUSIONS

Both AIF and CIF are relatively rare conditions and most of the published work presents evidence from small, single-centre studies. Much remains to be investigated to improve the diagnosis and management of IF and future studies should rely on multidisciplinary, multicentre and multinational collaborations that gather data from large cohorts of patients. Emphasis should also be placed on partnership with patients, carers and government agencies in order to improve the quality of research that focuses on patient-centred outcomes that will help to improve both outcomes and quality of life in patients with this devastating condition.

Surgeon's perspective on short bowel syndrome: Where are we?

Short bowel syndrome (SBS) is due to a massive loss of small bowel: the reduction of gut function is below the minimum necessary to maintain health (in adults) and growth (in children) so intravenous supplementation is required. Parenteral nutrition represents the milestone of treatment and surgical attempts should be limited only when the residual bowel is sufficient to increase absorption, reducing diarrhea and slowing the transit time of nutrients, water and electrolytes. The surgical techniques lengthen the bowel (tapering it) or reverse a segment of it: developed in children, nowadays are popular also among adults. The issue is mainly represented by the residual length of the small bowel where ileum has shown increased adaptive function than jejunum, but colon should be considered because of its importance in the digestive process. These concepts have been translated also in intestinal transplantation, where a colonic graft is nowadays widely used and the terminal ileum is the selected segment for a living-related donation. The whole replacement by a bowel or multivisceral transplant is still affected by poor long term outcome and must be reserved to a select population of SBS patients, affected by intestinal failure associated with irreversible complications of parenteral nutrition.

What's new in short bowel syndrome?

PURPOSE OF REVIEW

Short bowel syndrome (SBS) is a rare disease but with many complications due to intestinal failure, parenteral nutrition and underlying disease. A better prevention, comprehension and treatment could improve the outcome of these patients.

RECENT FINDINGS

Recent studies have been published on acute intestinal failure, first cause of SBS, and gives us strategy to avoid extended intestinal resection and thus SBS. There has been progress in the comprehension of intestinal adaptation, characterized by improvements in intestinal absorption, changes on hormonal secretion, development of a hyperphagia and dysbiosis of the gut microbiota. Hormonal treatment focusing on intestinal rehabilitation by promoting intestinal hyperadaptation has been proposed in patients with SBS, who require parenteral nutrition and intravenous fluids, such as glucagon-like peptide-2 (GLP-2) analog which is now recommended by the latest European Society for Clinical Nutrition and Metabolism Guidelines.

SUMMARY

Multimodal treatment of acute meseteric ischemia may avoid intestinal resection and is an effective prevention strategy for SBS. New understandings in intestinal adaptation can help us to optimize this adaptation, including with hormonal therapy. GLP-2 analog is now the treatment of reference in SBS patients with chronic intestinal failure.

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.

Pre-emptive Intestinal Transplant: The Surgeon's Point of View

Pre-emptive transplantation is a well-established practice for certain types of end-organ failure such as in the use of kidney transplantation. For irreversible intestinal failure, total parenteral nutrition (TPN) remains the gold standard, due to the suboptimal long-term results of intestinal transplantation. As such, the only role for pre-emptive transplantation, if at all, will be for patients identified to be at high risk of complications and mortality while on definitive long-term TPN. In these patients, the timing of early listing and transplantation could become life-saving, taking into account that mortality on the waiting list is still the highest for intestinal candidates. The development of simulation models or pre-transplant scoring systems could help in selecting patients based on potential outcome on TPN or with transplantation, and recent reports from high-volume centers identify few underlying pathologic conditions and some TPN complications as at higher risk of increased morbidity and mortality. A pre-emptive transplant could be used as a rehabilitative procedure in a well-selected case-by-case scenario, among TPN patients at risk of liver failure, repeated central line infections, mesenteric infarction, short bowel syndrome (SBS) <50 cm or with end stoma, congenital mucosal disease, desmoid tumors: These conditions must be carefully evaluated, not to underestimate the clinical stage nor to over-estimate the impact of a temporary situation. At the present time, diseases with a variable and unpredictable course, such as intestinal dysmotility disorders, or quality of life and financial issues are still far from being considered as indications for a pre-emptive transplant.

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.

Reversed Intestinal Segment Revisited

BACKGROUND

Reversed segments (RS) designed to slow intestinal transit and improve absorption in patients with short bowel syndrome (SBS) are performed infrequently, and patient selection remains controversial. Our aim was to evaluate patient selection and outcome for RS in SBS patients.

METHODS

Sixteen adult patients underwent RS among 520 SBS patients. All patients had remnant length >80 cm and rapid intestinal transit. Ten patients had a colon remnant and 12 had an ostomy. SBS was present for 8 to 150 months prior to RS.

RESULTS

RS was performed either alone (n = 9) or concurrently with ostomy closure (n = 5) or creation (n = 2). There were 3 postoperative complications and no deaths. Three patients had bacterial overgrowth. One required repair of an ileocolonic stricture. Two reversed segments were taken down 12 months and 96 months later. Two patients subsequently underwent serial transverse enteroplasty (STEP) procedures, and 1 had isolated intestinal transplant. Fourteen (88%) required parenteral nutrition (PN) pre-operatively and 2 (12%) had intractable diarrhea. Nine (56%) patients improved and 7 (44%) remained on PN or had persistent intractable diarrhea. Patients with a successful outcome were similar to those without improvement with respect to ostomy takedown, duration of SBS, Crohn's disease, intestinal length, a colon remnant, anatomy, and transit time.

CONCLUSIONS

Reversed segments significantly benefit one half of selected SBS patients who have rapid transit but adequate remnant length. Outcome in individual patients remains difficult to predict. Subsequent operation is frequently required. This procedure is applicable to a small proportion of SBS patients.

Surgical management and autologous intestinal reconstruction in short bowel syndrome

Short bowel syndrome (SBS) is a serious condition with considerable morbidity and mortality. When treatment with parenteral nutrition fails and life-threatening complications occur, autologous intestinal reconstruction (AIR) should be considered before intestinal transplantation (ITx). Single or combined ITx should be reserved for patients with severe liver disease and as last resort in the treatment of SBS. Longitudinal intestinal lengthening and tailoring (LILT) has proven its value in AIR, but its availability depends on the expertise of the surgeons. Serial transverse enteroplasty (STEP) has similar success rates as LILT and fewer patients progress to ITx. STEP is also applicable at small bowel dilatation in ultra-short bowel syndrome. The scope may be widened when duodenal dilatation can be treated as well. Spiral intestinal lengthening and tailoring (SILT) is a promising alternative. More research is needed to confirm these findings. Therefore we suggest an international data registry for all intestinal lengthening procedures.

ESPEN guidelines on chronic intestinal failure in adults

BACKGROUND & AIMS

Chronic Intestinal Failure (CIF) is the long-lasting reduction of gut function, below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth. CIF is the rarest organ failure. Home parenteral nutrition (HPN) is the primary treatment for CIF. No guidelines (GLs) have been developed that address the global management of CIF. These GLs have been devised to generate comprehensive recommendations for safe and effective management of adult patients with CIF.

METHODS

The GLs were developed by the Home Artificial Nutrition & Chronic Intestinal Failure Special Interest Group of ESPEN. The GRADE system was used for assigning strength of evidence. Recommendations were discussed, submitted to Delphi rounds, and accepted in an online survey of ESPEN members.

RESULTS

The following topics were addressed: management of HPN; parenteral nutrition formulation; intestinal rehabilitation, medical therapies, and non-transplant surgery, for short bowel syndrome, chronic intestinal pseudo-obstruction, and radiation enteritis; intestinal transplantation; prevention/treatment of CVC-related infection, CVC-related occlusion/thrombosis; intestinal failure-associated liver disease, gallbladder sludge and stones, renal failure and metabolic bone disease. Literature search provided 623 full papers. Only 12% were controlled studies or meta-analyses. A total of 112 recommendations are given: grade of evidence, very low for 51%, low for 39%, moderate for 8%, and high for 2%; strength of recommendation: strong for 63%, weak for 37%.

CONCLUSIONS

CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for both the underlying gastrointestinal disease and to provide HPN support. The rarity of the condition impairs the development of RCTs. As a consequence, most of the recommendations have a low or very low grade of evidence. However, two-thirds of the recommendations are considered strong. Specialized management and organization underpin these recommendations.

The Surgical Approach to Short Bowel Syndrome - Autologous Reconstruction versus Transplantation

BACKGROUND

Short bowel syndrome (SBS) is a state of malabsorption resulting from massive small bowel resection leading to parenteral nutrition (PN) dependency. Considerable advances have been achieved in the medical and surgical management of SBS over the last few decades.

METHODS

This review discusses in detail the surgical approach to SBS.

RESULTS

Widespread use of PN enables long-term survival in patients with intestinal failure but at the cost of PN-associated life-threatening complications including catheter-associated blood stream infection, venous thrombosis, and liver disease. The goal of management of intestinal failure due to SBS is to enable enteral autonomy and wean PN by means of a multi-disciplinary approach. Availability of modified enteral feeding formulas have simplified nutrition supplementation in SBS patients. Similarly, advances in the medical field have made medications like growth hormone and glucagon-like peptide (GLP2) available to improve water and nutrient absorption as well as to enable achieving enteral autonomy. Autologous gastrointestinal reconstruction (AGIR) includes various techniques which manipulate the bowel surgically to facilitate the bowel adaptation process and restoration of enteral nutrition. Ultimately, intestinal transplantation can serve as the last option for the cure of intestinal failure when selectively applied.

CONCLUSION

SBS continues to be a challenging medical problem. Best patient outcomes can be achieved through an individualized plan, using various AGIR techniques to complement each other, and intestinal transplantation as a last resort for cure. Maximum benefit and improved outcomes can be achieved by caring for SBS patients at highly specialized intestinal rehabilitation centers.

Autologous intestinal reconstruction surgery as part of comprehensive management of intestinal failure

Pediatric intestinal failure (IF) remains to be associated with significant morbidity and mortality, the most frequent underlying etiologies being short bowel syndrome (SBS), and primary motility disorders. Management aims to assure growth and development, while preventing complications and facilitating weaning off parenteral support (PS) by fully utilizing adaptation potential of the remaining gut. Probability of survival and weaning off PS is improved by coordinated multidisciplinary intestinal rehabilitation combining individualized physiological enteral and parenteral nutrition (PN), meticulous central line care and medical management with carefully planned surgical care. Increasing evidence suggests that autologous intestinal reconstruction (AIR) surgery is effective treatment for selected short bowel patients. Bowel lengthening procedures normalize pathological adaptation-associated short bowel dilatation with potential to support intestinal absorption and liver function by various mechanisms. Although reversed small intestinal segment, designed to prolong accelerated intestinal transit, improves absorption in adult SBS, its feasibility in children remains unclear. Controlled bowel obstruction to induce dilatation followed by bowel lengthening aims to gain extra length in patients with the shortest duodenojejunal remnant. Reduced PS requirement limits the extent of complications, improving prognosis and quality of life. The great majority of children with SBS can be weaned from PS while prognosis of intractable primary motility disorders remains poor without intestinal transplantation, which serves as a salvage therapy for life-threatening complications such as liver failure, central vein thrombosis or recurrent bloodstream infections.

Intestinal deletion of leptin signaling alters activity of nutrient transporters and delayed the onset of obesity in mice

The importance of B-isoform of leptin receptor (LEPR-B) signaling in the hypothalamus, pancreas, or liver has been well characterized, but in the intestine, a unique site of entry for dietary nutrition into the body, it has been relatively ignored. To address this question, we characterized a mouse model deficient for LEPR-B specifically in intestinal epithelial cells (IECs). (IEC)LEPR-B-knockout (KO) and wild-type (WT) mice were generated by Cre-Lox strategy and fed a normal or high-fat diet (HFD). The analyses of the animals involved histology and immunohistochemistry of intestinal mucosa, indirect calorimetric measurements, whole-body composition, and expression and activities of nutrient transporters. (IEC)LEPR-B-KO mice exhibited a 2-fold increase in length of jejunal villi and have normal growth on a normal diet but were less susceptible (P<0.01) to HFD-induced obesity. No differences occurred in energy intake and expenditure between (IEC)LEPR-B-WT and -KO mice, but (IEC)LEPR-B-KO mice fed an HFD showed increased excreted fats (P<0.05). Activities of the Na(+)/glucose cotransporter SGLT-1 and GLUT2 were unaffected in LEPR-B-KO jejunum, while GLUT5-mediated fructose transport and PepT1-mediated peptide transport were substantially reduced (P<0.01). These data demonstrate that intestinal LEPR-B signaling is important for the onset of diet-induced obesity. They suggest that intestinal LEPR-B could be a potential per os target for prevention against obesity.

Short bowel syndrome and small bowel transplantation

PURPOSE OF REVIEW

The purpose of this review is to provide an update of recent advances in the areas of short bowel syndrome (SBS) and small bowel transplantation (SBT).

RECENT FINDINGS

Recent reports from two of the largest multicenter randomized, controlled trials in patients with SBS support the safety and efficacy of teduglutide as an aid to parenteral nutrition weaning. In well selected SBS patients, outcomes as diverse as survival, macronutrient absorption and parenteral nutrition weaning are improved after autologous gastrointestinal reconstructive surgery. SBT is no longer considered investigational and given improved outcomes noted in recent reports, indications for transplantation are expanding. Although SBT early survival rates are approaching those of other organ allografts, long-term graft survival remains suboptimal.

SUMMARY

Recently available trophic factors hold promise as aids in restoring freedom from parenteral nutrition support; however, their long-term benefits, preferred timing of administration in relation to the onset of SBS, optimal patient selection for use, duration of treatment and cost effectiveness require further study. Despite recent evidence of improved early survival after SBT, more dedicated research is needed to design more effective strategies to better tolerize small bowel grafts, prevent rejection and, ultimately, improve long-term outcomes. Reserved for well selected patients, autologous gastrointestinal reconstruction should be considered complementary and not antagonistic to SBT.