Management of short bowel syndrome

Building gut from scratch - progress and update of intestinal tissue engineering

Short bowel syndrome (SBS), a condition defined by insufficient absorptive intestinal epithelium, is a rare disease, with an estimated prevalence up to 0.4 in 10,000 people. However, it has substantial morbidity and mortality for affected patients. The mainstay of treatment in SBS is supportive, in the form of intravenous parenteral nutrition, with the aim of achieving intestinal autonomy. The lack of a definitive curative therapy has led to attempts to harness innate developmental and regenerative mechanisms to engineer neo-intestine as an alternative approach to addressing this unmet clinical need. Exciting advances have been made in the field of intestinal tissue engineering (ITE) over the past decade, making a review in this field timely. In this Review, we discuss the latest advances in the components required to engineer intestinal grafts and summarize the progress of ITE. We also explore some key factors to consider and challenges to overcome when transitioning tissue-engineered intestine towards clinical translation, and provide the future outlook of ITE in therapeutic applications and beyond.

Anastomotic ulcers in short bowel syndrome: New suggestions from a multidisciplinary approach

BACKGROUND AND AIMS

Anastomotic ulceration (AU) is a rare potential life-threatening complication that may occur after intestinal resection. The diagnosis is often delayed after a long-lasting history of refractory anemia. The pathogenesis remains unknown and there are no established therapies. The aim of the study was to analyze the medical history of children with short bowel syndrome (SBS) who were experiencing AU.

METHODS

Records of SBS children were retrospectively reviewed. Demographics, baseline characteristics, presentation, diagnosis and treatment of AU cases were analyzed.

RESULTS

Eight out of 114 children with SBS were identified as having AU. Mean gestational age was 32.5weeks. Underlying diseases were: 5 necrotising enterocolitis, 2 gastroschisis and 1 multiple intestinal atresia. The mean age at AU diagnosis was 6.5years (diagnosis delay of 35months). All but 2 patients had AU persistency after medical treatment. Endoscopic treatment (2 argon plasma coagulation; 1 platelet-rich fibrin instillation; 2 endoscopic hydrostatic dilations) was effective in 3 out of 5 children. Surgery was required in 3 patients.

CONCLUSIONS

Severe bowel ischemic injury, especially in preterm infant, could predispose to AU development. Medical treatment showed discouraging results. We firstly described that different endoscopic treatment could be attempted before resorting to further surgery.

LEVEL OF EVIDENCE

IV.

A comparison of lipid minimization strategies in children with intestinal failure

PURPOSE

The purpose of this study was to compare outcomes of lipid minimization with either Intralipid (IL) or Omegaven® in children with intestinal failure (IF) who developed intestinal failure-associated liver disease (IFALD) while receiving parenteral nutrition (PN).

METHODS

A retrospective review of children with IF requiring PN who developed IFALD (direct bilirubin >2 mg/dL) while receiving IL (2009-2016) was performed. Clinical characteristics, nutritional, and laboratory values were compared between children treated with reduced IL or Omegaven®.

RESULTS

16 children were reviewed (8 treated with IL and 8 treated with Omegaven® at a median dose of 1g/kg/d). Both groups had similar demographics, small bowel length, and parenteral nutritional intake during the study (82.9±27.1 kcal/kg/d vs. 75.9±16.5 kcal/kg/d, p=0.54). The mean direct bilirubin (DBili) prior to initiating treatment was 7.8±4.3 mg/dL and 7.5±3.5 mg/dL (p=0.87) in the IL and Omegaven® groups, respectively. The IL group took a median of 113 days to achieve a DBili <0.5 mg/dL compared to 124 days in the Omegaven® group (p=0.49). There were no differences in markers of liver function or growth trajectories among groups.

CONCLUSIONS

Lipid minimization with either IL or Omegaven® has similar success in achieving a normal DBili in children with IF and IFALD without major differences in nutritional status or growth.

TYPE OF STUDY

Treatment Study LEVEL OF EVIDENCE: III.

A pilot study of ultrasound elastography as a non-invasive method to monitor liver disease in children with short bowel syndrome

BACKGROUND

Our objective was to evaluate the accuracy of acoustic radiation force impulse (ARFI) elastography in determining extent of liver fibrosis in pediatric patients with short bowel syndrome (SBS).

METHODS

This prospective cohort study included pediatric patients with SBS who underwent ultrasound with ARFI measurements of shear wave speed (SWS) and liver biopsy within 30days of each other between 12/2014-9/2015. The mean and median SWS were compared to the stage of fibrosis. Receiver operating characteristic curves (ROC) were also generated to assess the classification accuracy of SWS measurements for mild (F0-F1) versus moderate/severe fibrosis (F2-F4).

RESULTS

Twelve patients were included with median age 1.4years and median weight 11.3kg. The median direct bilirubin level was 0.3mg/dL at the time of biopsy. On liver biopsy, 6 patients had mild fibrosis (F1), 3 had septal fibrosis (F3), and 3 had cirrhosis (F4). The area under the ROC curve for elastography to differentiate moderate/severe liver fibrosis from mild disease was 0.83 (95CI 0.58-1.00) and 0.86 (95CI 0.63-1.00) for the median SWS and mean SWS, respectively.

CONCLUSIONS

These early results suggest that ARFI ultrasound elastography may be a reliable non-invasive method to monitor liver fibrosis in pediatric patients with SBS.

TYPE OF STUDY

Prospective observational cohort.

LEVEL OF EVIDENCE

3.

Predicting time to full enteral nutrition in children after significant bowel resection

PURPOSE

Parenteral nutrition (PN) contributes to considerable morbidity in children after significant bowel resection. This study evaluates the utility of clinical variables in predicting time to independence from PN.

METHODS

After IRB approval, a retrospective review (1999-2012) of 71 children who were on PN for >6weeks after intestinal resection and successfully weaned was performed. Clinical characteristics were evaluated to determine the relationship to time to full enteral nutrition. P-values<0.05 were significant.

RESULTS

Most children had necrotizing enterocolitis (56%), intestinal atresia (20%), or gastroschisis (11%) with a median small bowel length of 55cm (IQR, 35-92cm). The duration of PN was independent of the etiology of intestinal loss, presence of the ileocecal valve or colon, or location of anastomosis, but was strongly associated with small bowel length (<0.01) and percent of expected small bowel based on gestational age (GA) (median 50%, <0.01). In general, children who had 25-50% of their small bowel were dependent on PN for at least 2years compared to approximately 1year for those with 51-75%.

CONCLUSION

The duration of PN dependence in children after major bowel resection is best predicted by remaining small bowel length and can be estimated using a linear regression model.

LEVEL OF EVIDENCE

2b.

Intestinal injury in the rat model of 17α-ethynylestradiol-induced intrahepatic cholestasis

OBJECTIVE

Although the intimate relationship between liver and gut has been previously reported under physiological and pathological conditions, intestinal involvement in the process of intrahepatic cholestasis of pregnancy remains unclear. The aim of this study was to investigate intestinal changes in 17α-ethynylestradiol (EE)-induced cholestatic rat model.

METHODS

Liver injury was assessed by HE stain and serum biochemical parameters were measured. Intestinal transit was determined using ink marks. Neuronal protein expressions in the intestine were analyzed by Western blot.

RESULTS

EE treatment induced liver damage, including severe bile duct hyperplasia, portal edema, portal infiltration, a loss of hepatic structure in periportal areas and increased serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and total bilirubin. Large areas of inflammatory cell infiltration and increased myeloperoxidase activity were observed in the intestine of EE-induced cholestatic rats. The EE-treated group showed increased intestinal transit and malondialdehyde levels, while the glutathione content and superoxide dismutase activity were notably decreased, together with decreased protein gene product 9.5 and neuronal nitric oxide synthase expression in the ileum and colon. Furthermore, choline acetyltransferase expression was significantly decreased in the ileum, whereas no change was observed in the colon of EE-treated rats.

CONCLUSION

EE-induced liver damage is associated with oxidative stress, inflammation and neural loss in the intestine, which may lead to altered intestinal motility.

Progression in children with intestinal failure at a referral hospital in Medellín, Colombia

BACKGROUND

Patients with intestinal failure are unable to maintain adequate nutrition and hydration due to a reduction in the functional area of the intestine. Different strategies have the potential to benefit these patients by promoting intestinal autonomy, enhancing quality of life, and increasing survival.

AIMS

To describe the clinical characteristics of children with intestinal failure and disease progression in terms of intestinal autonomy and survival.

MATERIALS AND METHODS

A retrospective study was conducted, evaluating 33 pediatric patients with intestinal failure that were hospitalized within the time frame of December 2005 and December 2013 at a tertiary care referral center. Patient characteristics were described upon hospital admission, estimating the probability of achieving intestinal autonomy and calculating the survival rate.

RESULTS

Patient median age upon hospital admission was 2 months (interquartile range [IQR]: 1-4 months) and 54.5% of the patients were boys. Intestinal autonomy was achieved in 69.7% of the cases with a median time of 148 days (IQR: 63 - 431 days), which decreased to 63 days in patients with a spared ileocecal valve. Survival was 91% during a median follow-up of 281 days (IQR: 161 - 772 days).

CONCLUSIONS

Medical management of patients with intestinal failure is complex. Nutritional support and continuous monitoring are of the utmost importance and long-term morbidity and mortality depends on the early recognition and management of the associated complications.

Generation of tissue-engineered small intestine using embryonic stem cell-derived human intestinal organoids

Short bowel syndrome (SBS) is characterized by poor nutrient absorption due to a deficit of healthy intestine. Current treatment practices rely on providing supportive medical therapy with parenteral nutrition; while life saving, such interventions are not curative and are still associated with significant co-morbidities. As approaches to lengthen remaining intestinal tissue have been met with only limited success and intestinal transplants have poor survival outcomes, new approaches to treating SBS are necessary. Human intestine derived from embryonic stem cells (hESCs) or induced pluripotent stem cells (iPSCs), called human intestinal organoids (HIOs), have the potential to offer a personalized and scalable source of intestine for regenerative therapies. However, given that HIOs are small three-dimensional structures grown in vitro, methods to generate usable HIO-derived constructs are needed. We investigated the ability of hESCs or HIOs to populate acellular porcine intestinal matrices and artificial polyglycolic/poly L lactic acid (PGA/PLLA) scaffolds, and examined the ability of matrix/scaffolds to thrive when transplanted in vivo. Our results demonstrate that the acellular matrix alone is not sufficient to instruct hESC differentiation towards an endodermal or intestinal fate. We observed that while HIOs reseed acellular porcine matrices in vitro, the HIO-reseeded matrices do not thrive when transplanted in vivo. In contrast, HIO-seeded PGA/PLLA scaffolds thrive in vivo and develop into tissue that looks nearly identical to adult human intestinal tissue. Our results suggest that HIO-seeded PGA/PLLA scaffolds are a promising avenue for developing the mucosal component of tissue engineered human small intestine, which need to be explored further to develop them into fully functional tissue.

Summary: HIO-seeded PGA/PLLA scaffolds thrive in vivo and develop into tissue that looks nearly identical to adult human intestinal tissue. These scaffolds appear to be suitable for further tissue engineering approaches to develop functional intestine.

Protein-engineered scaffolds for in vitro 3D culture of primary adult intestinal organoids

Though in vitro culture of primary intestinal organoids has gained significant momentum in recent years, little has been done to investigate the impact of microenvironmental cues provided by the encapsulating matrix on the growth and development of these fragile cultures. In this work, the impact of various in vitro culture parameters on primary adult murine organoid formation and growth are analyzed with a focus on matrix properties and geometric culture configuration. The air-liquid interface culture configuration was found to result in enhanced organoid formation relative to a traditional submerged configuration. Additionally, through use of a recombinantly engineered extracellular matrix (eECM), the effects of biochemical and biomechanical cues were independently studied. Decreasing mechanical stiffness and increasing cell adhesivity were found to increase organoid yield. Tuning of eECM properties was used to obtain organoid formation efficiency values identical to those observed in naturally harvested collagen I matrices but within a stiffer construct with improved ease of physical manipulation. Increased ability to remodel the surrounding matrix through mechanical or enzymatic means was also shown to enhance organoid formation. As the engineering and tunability of recombinant matrices is essentially limitless, continued property optimization may result in further improved matrix performance and may help to identify additional microenvironmental cues that directly impact organoid formation, development, differentiation, and functional behavior. Continued culture of primary organoids in recombinant matrices could therefore prove to be largely advantageous in the field of intestinal tissue engineering for applications in regenerative medicine and in vitro tissue mimics.

Review of trace mineral requirements for preterm infants: what are the current recommendations for clinical practice?

Inadequate nutrient stores at birth are an inevitable consequence of being born prematurely. Preterm infants also have high nutrient requirements, which increase with earlier gestational ages. As a result, early nutrition intervention is required to prevent further deficits that, if not corrected, can affect growth and long-term outcomes. Preterm infants often require several weeks of parenteral nutrition (PN) support, which includes trace mineral supplementation. Trace minerals are considered essential nutrients, unable to be synthesized in the human body. Deficiencies of trace minerals have been reported, yet evidence-based guidelines for assessment and supplementation have not been clearly defined. Food and Drug Administration-approved parenteral trace mineral intake guidelines are more than 30 years old. In an effort to more clearly define trace mineral supplementation and monitoring guidelines for preterm infants, a review of literature was performed with the purpose to (1) summarize trace mineral roles in preterm infants, (2) describe clinical signs of deficiency and toxicity, and (3) present intake recommendations and considerations for preterm infants based on current available literature. Review of literature was completed using PubMed and Cochrane databases to find relevant studies specific to trace mineral requirements for preterm infants, trace mineral supplementation of PN, human milk fortifiers, and preterm infant formulas. Review of literature supports that trace mineral depletion can lead to clinical compromise in preterm infants; therefore, suggesting that every effort be made to ensure adequate provision of trace minerals is given to preterm infants. Practical considerations for the clinical nutrition management of preterm infants were also identified in this review.

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.