Clinical challenges of short bowel syndrome and the path forward for organoid-based regenerative medicine

Short bowel syndrome (SBS) is a rare condition, the main symptom of which is malabsorption following extensive resection of the small intestine. Treatment for SBS is mainly supportive, consisting of supplementation, prevention and treatment of complications, and promotion of intestinal adaptation. While development of parenteral nutrition and drugs promoting intestinal adaptation has improved clinical outcomes, the prognosis of patients with SBS remains poor. Intestinal transplantation is the only curative therapy but its outcome is unsatisfactory. In the absence of definitive therapy, novel treatment is urgently needed. With the advent of intestinal organoids, research on the intestine has developed remarkably in recent years. Concepts such as the "tissue-engineered small intestine" and "small intestinalized colon," which create a functional small intestine by combining organoids with other technologies, are potentially novel regenerative therapeutic approaches for SBS. Although they are still under development and there are substantial issues to be resolved, the problems that have prevented establishment of the complex function and structure of the small intestine are gradually being overcome. This review discusses the current treatments for SBS, the fundamentals of the intestine and organoids, the current status of these new technologies, and future perspectives.

The role of gastrostomy feeding during intestinal rehabilitation for children with short bowel syndrome

PURPOSE

Following extensive bowel resection, many children with short bowel syndrome (SBS) are routinely offered a placement of gastrostomy tube (G-tube) for feeding. This nutritional pathway is aimed to accommodate the gastric and small bowel motor disturbances related to SBS, and to promote weaning off parenteral nutrition (PN) to achieve enteral autonomy (EA). The aim of this study was to investigate the effect of gastrostomy feeding in outcomes of children with SBS.

METHODS

A retrospective cohort of all SBS children managed at our multidisciplinary Intestinal Rehabilitation Center as part of an Intestinal Rehabilitation Program. SBS was defined as PN dependence for more than six weeks following extensive bowel resection. Patients treated with G-tube feeding were compared with patients without G-tube in terms of PN duration, reaching EA, physical development, and surgical parameters.

RESULTS

A total of 36 SBS patients diagnosed between 2003 and 2022 were included. The most common etiologies included congenital intestinal atresia (31%) and necrotizing enterocolitis (25%). SBS-G-tube (group A) contained 20 children, and SBS (group B) contained 16 children. A total of 21 children reached EA (58%); ten from group A (50%), and 11 from group B (69%) (p > 0.05). Within EA patients, mean PN duration was 49 ± 44 months in group A, and 24 ± 33 months in group B (p > 0.05). Patients who reached EA had 22% longer residual small bowel when compared with PN-dependent patients (p = 0.003). However, the outcomes were adjusted for residual small and large bowel length and percentages, a residual ileocecal valve, and a colon in continuity with no differences between the groups. Two-thirds of children from group A reported G-tube related complications (mechanical, bleeding, or infections). We did not find differences in mean height and weight percentiles between the groups (p > 0.05).

CONCLUSION

We did not find significant advantage of gastrostomy feeding in reaching EA. Because there are surgical and mechanical complications related to this procedure, further prospective studies are required to determine G-tube relevance for children with SBS.

Motility disorders in children with intestinal failure: a national tertiary referral center experience

PURPOSE

Intestinal dysmotility (ID) problems are common in patients with pediatric-onset intestinal failure (IF) and short bowel syndrome (SBS), leading to significant morbidity and delays in the advancement of enteral nutrition (EN). We aimed to investigate the clinical features and complications of ID in children with IF and SBS.

METHODS

Retrospective chart review of all children with IF and/or SBS who required parenteral nutrition (PN) > 6 weeks or small-intestinal resection ≥ 50%. Patients were divided into SBS and non-SBS groups. SBS group was divided into two subgroups: with and without ID. Patients with ID were identified (clinically, radiologically and functionally) and analyzed with regard to demographics, intestinal anatomy, complications and outcomes (short and long term).

RESULTS

A total of 42 children with IF were treated in our institution during 2003-2022. In non-SBS group (n = 10), ID was the most common cause of IF (80%). SBS-group included 32 children; 18 children (56%) developed ID. The clinical profile of SBS-ID patients (vs SBS) was: female gender (56%), remaining small bowel length ≤ 55 cm, estimated residual small bowel ≤ 28% (p = 0.045) and absence of ICV (56%). Common symptoms of the SBS-ID group were: food intolerance (61%), abdominal distension (50%), vomiting (44%), malabsorption and severe constipation. Complications included FTT (67%) (p = 0.003), bacterial overgrowth with subsequent bloodstream infection (33%) (p = 0.75), and lactic acidosis (11%). Lengthening procedure (STEP) was performed in 11 SBS-ID patients (61%) (p = 0.002). In all patients, STEP operation "rescued" their dysfunctional intestine. Eight of these patients (73%) were weaned from TPN. Survival rate was 100%; however, one SBS-ID patient is a candidate for combined intestinal and liver transplantation.

CONCLUSIONS

ID is the most common complication of SBS and is the most common cause of IF in non-SBS patients. ID has a high morbidity rate and various clinical manifestations. Successful treatment of these infants may be achieved with the use of tapering enteroplasty.

The Importance of the ileocecal valve and colon in achieving intestinal independence in infants with short bowel syndrome

PURPOSE

Infants with short bowel syndrome (SBS) wean from parenteral nutrition (PN) support at variable rates. Small bowel length is a predictor, but the importance of the ileocecal valve (ICV) and colon are unclear. We aim to determine if the ICV and/or colon predict enteral autonomy.

METHODS

Infants from a single intestinal rehabilitation program were retrospectively reviewed. Etiology of SBS, intestinal anatomy, and duration of nutritional support were collected for three years. The primary outcome was time to full enteral nutrition. ANCOVA and Cox proportional hazards model were used, with p < 0.05 significant.

RESULTS

55 infants with SBS were included. After accounting for the effect of small bowel, PN duration was shorter for infants with the ICV compared to those without (mean 218 vs. 538 days, p = 0.003), and had a more significant effect on infants with ≤50% of small bowel. Increased small bowel length was a positive predictor of weaning. Patients with ≤50% of colon spent less time on PN with the ICV, compared to without (mean 220 vs 715 days, p = 0.009).

CONCLUSIONS

Preservation of the ICV was associated with shorter duration of PN support, while colon was not. Small bowel length is a positive predictor of enteral autonomy.

LEVEL OF EVIDENCE

Level III retrospective comparative study TYPE OF STUDY: Retrospective review.

An overview of the current management of short-bowel syndrome in pediatric patients

Short-bowel syndrome (SBS) is defined as a state of malabsorption after resection or loss of a major portion of the bowel due to congenital or acquired factors. This article presents an overview on the recent management of pediatric SBS. The pediatric SBS population is very heterogeneous. The incidence of SBS is estimated to be 24.5 per 100,000 live births. The nutritional, medical, and surgical therapies available require a comprehensive evaluation. Thus, multidisciplinary intestinal rehabilitation programs (IRPs) are necessary for the management of these complex patients. The key points of focus in IRP management are hepato-protective strategies to minimize intestinal failure-associated liver disease; the aggressive prevention of catheter-related bloodstream infections; strategic nutritional supply to optimize the absorption of enteral calories; and the management and prevention of small bowel bacterial overgrowth, nephrocalcinosis, and metabolic bone disease. As the survival rate of children with SBS currently exceeds 90%, the application of small bowel transplantation has been evolving. The introduction of innovative treatments, such as combined therapy of intestinotrophic hormones, including glucagon-like peptide-2, may lead to further improvements in patients' quality of life.

Predictors of Intestinal Adaptation in Children

In children, short-bowel syndrome (SBS) accounts for two-thirds of the cases of intestinal failure, and motility disorders and congenital mucosal diarrheal disorders account for the remaining one-third. Children with SBS are supported primarily by parenteral nutrition, which is the single-most important therapy contributing to their improved prognosis. More than 90% of children with SBS who are cared for at experienced intestinal rehabilitation programs survive, and roughly 60% to 70% undergo intestinal adaptation and achieve full enteral autonomy. This article focuses on the predictors of pediatric intestinal adaptation and discusses the pathophysiology and clinical management of children with SBS.