New Insights Into the Indications for Intestinal Transplantation: Consensus in the Year 2019

Short bowel syndrome related intestinal failure outcomes in Latin America: Insights from the RESTORE Registry

BACKGROUND

Short bowel syndrome is considered a low prevalence disease. The scant information available about intestinal failure in Latin America was the driving force to expand this registry.

METHODS

A prospective, multicenter observational registry was created for patients with chronic intestinal failure short bowel at specialized centers in Latin America. Demographics, clinical characteristics, nutrition assessment, parenteral nutrition management, intestinal rehabilitation, related complications, clinical outcome, and survival were analyzed.

RESULTS

From May 2020 to July 2023, 167 patients (115 adults, 52 children) from 20 centers were enrolled. For the adults, the mean age was 37.2 ± 18 years, 48% were female, and the mean follow-up was 22.6 ± 18.3 months. The main etiology was surgical resections (postsurgical complications: 37%; ischemia: 25%); the mean intestinal length was 73 ± 55 cm. The complications were as follows: infections: 0.4/1000 catheter-days; thrombosis: 0.24/1000 catheter-days; liver disease: 2.6%. The outcomes were as follows: 28% were rehabilitated, 15% died, 9.6% were lost to follow-up, 0.9% underwent transplant, and 45.6% continued follow-up. For the children, the mean age 48 ± 52 months, 48% were female, 52% were premature. The mean follow-up was 17.2 ± 5.6 months; the mean remaining intestinal length was 38 ± 45 cm. The leading etiologies were atresia (25%), NEC (23%), and gastroschisis (21%). The complication were as follows: infections: 2/1000 catheter-days; thrombosis: 2.22/1000 catheter-day; 25% developed liver disease. The outcomes were as follows: 7.7% died, 3.8% were rehabilitated, and 88.5% continued follow-up.

CONCLUSION

The RESTORE amendment served as a registry and educational tool for the participating teams. The aspiration is to objectively show current aspects of intestinal failure in the region and carry them to international standards. Including all Latin American countries and etiologies of chronic intestinal failure besides short gut would serve to complete this registry.

Intestinal transplantation: Significance of immune responses

Intestinal allografts, with many resident immune cells and as a destination for circulating lymphocytes of the recipient, appear to be the most challenging solid organ transplants. The high incidence of acute rejection and frequent reports of fatal graft-versus-host disease (GvHD) after intestinal transplantation call for more research to describe the molecular mechanisms involved in the immunopathogenesis of post-transplant complications to define new therapeutic targets. In addition, according to the rapid development of immunosuppressive agents, it is time to consider novel therapeutic approaches in managing treatment-refractory patients with rejection or severe GvHD. Herein, the main immunological challenges before and after intestinal transplant including, brain-dead donor inflammation, acute rejection, antibody-mediated, and chronic rejections, as well as GvHD have been described. Besides, the new immune-based therapies used in experimental and clinical settings to improve tolerance toward intestinal allograft, and cases of operational tolerance have been reviewed.

Pediatric Chronic Intestinal Failure: Something Moving?

Pediatric chronic intestinal failure (PIF) is a rare and heterogeneous condition characterized by the inability of the patient's intestine to adequately absorb the required fluids and/or nutrients for growth and homeostasis. As a result, patients will become dependent on home parenteral nutrition (HPN). A MEDLINE search was performed in May 2024 with keywords "intestinal failure", "parenteral nutrition" and "pediatric". Different underlying conditions which may result in PIF include short bowel syndrome, intestinal neuromuscular motility disorders and congenital enteropathies. Most common complications associated with HPN are catheter-related bloodstream infections, catheter-related thrombosis, intestinal failure-associated liver disease, small intestinal bacterial overgrowth, metabolic bone disease and renal impairment. Treatment for children with PIF has markedly improved with a great reduction in morbidity and mortality. Centralization of care in specialist centers and international collaboration between centers is paramount to further improve care for this vulnerable patient group. A recently promising medical therapy has become available for children with short bowel syndrome which includes glucagon-like peptide 2, a naturally occurring hormone which is known to delay gastric emptying and induce epithelial proliferation. Despite advances in curative and supportive treatment, further research is necessary to improve nutritional, pharmacological and surgical care and prevention of complications associated with parenteral nutrition use.

Indications and successes of intestinal transplantation in children in the 21st century: A retrospective cohort study

AIMS

To report the results and successes of intestinal transplantation (ITx) in the most active European centres, to emphasize that, although it is a difficult procedure, it should remain a therapeutic option for children with total, definitive and complicated intestinal failure when intestinal rehabilitation fails.

METHODS

We retrospectively collected data about all patients less than 18 receiving an ITx from 2010 to 2022 in 8 centres, and outcomes in July 2022.

RESULTS

ITx was performed in 155 patients, median age 6.9 years, in 45% for short bowel syndromes, 22% congenital enteropathies, 25% motility disorders, and 15% re-transplantations. Indications were multiple in most patients, intestinal failure-associated liver disease in half. The graft was in 70% liver-containing. At last follow up 64% were alive, weaned from parenteral nutrition, for 7.9 years; 27% had died and the graft was removed in 8%, mostly early after ITx.

DISCUSSION

ITx, despite its difficulties, can give a future to children with complicated intestinal failure. It should be considered among the therapeutic options offered to patients with a predicted survival rate lower than that after ITx. Patients should be early discussed within multidisciplinary teams in ITx centres, to avoid severe complications impacting the results of ITx, or even to avoid ITx.

Evaluation of pediatric patients for intestinal transplantation in the modern era

OBJECTIVES

To review recent evaluations of pediatric patients with intestinal failure (IF) for intestinal transplantation (ITx), waiting list decisions, and outcomes of patients listed and not listed for ITx at our center.

METHODS

Retrospective chart review of 97 patients evaluated for ITx from January 2014 to December 2021 including data from referring institutions and protocol laboratory testing, body imaging, endoscopy, and liver biopsy in selected cases. Survival analysis used Kaplan-Meier estimates and Cox proportional hazards regression.

RESULTS

Patients were referred almost entirely from outside institutions, one-third because of intestinal failure-associated liver disease (IFALD), two-thirds because of repeated infective and non-IFALD complications under minimally successful intestinal rehabilitation, and a single patient because of lost central vein access. The majority had short bowel syndrome (SBS). Waiting list placement was offered to 67 (69%) patients, 40 of whom for IFALD. The IFALD group was generally younger and more likely to have SBS, have received more parenteral nutrition, have demonstrated more evidence of chronic inflammation and have inferior kidney function compared to those offered ITx for non-IFALD complications and those not listed. ITx was performed in 53 patients. Superior postevaluation survival was independently associated with higher serum creatinine (hazard ratio [HR] 15.410, p = 014), whereas inferior postevaluation survival was associated with ITx (HR 0.515, p = 0.035) and higher serum fibrinogen (HR 0.994, p = 0.005).

CONCLUSIONS

Despite recent improvements in IF management, IFALD remains a prominent reason for ITx referral. Complications of IF inherent to ITx candidacy influence postevaluation and post-ITx survival.

Extended total colonic aganglionosis and total intestinal aganglionosis: Challenging enemies

AIM

Extended total colonic aganglionosis (ETCA) represents uncommon forms of Hirschsprung disease (HD), with aganglionosis extending into the proximal small bowel. ETCA management is challenging and associated with poor outcomes and high mortality. This study compares management and outcomes of ETCA to more common HD forms.

METHODS

A retrospective cohort of HD patients (2012-2023) from two institutions. Three HD forms were compared: short-segment HD (SSHD, n = 19), long-segment HD or total colonic aganglionosis (LS/TCA, n = 9) and ETCA (n = 7).

RESULTS

Normally innervated segments in ETCA patients ranged 0-70 cm. Median times to first surgery were; ETCA = 3 days versus TCA = 21 days (p = 0.017) and SSHD = 95 days (p < 0.001), respectively. Median number of surgeries were; ETCA = 4, versus TCA = 2 (p = 0.17) and SSHD = 1 (p = 0.002), respectively. All the patients underwent a definitive pull-through procedure, except four ETCA patients with a permanent jejunostomy and residual aganglionic segment of 57-130 cm. ETCA patients had 92% lower odds of enterocolitis (14%) compared to TCA patients (67%, p = 0.054), and comparable odds to SSHD patients (16%, p = 0.92). ETCA mortality was 14%.

CONCLUSION

Extended total colonic aganglionosis patients require earlier and multiple interventions. Leaving an aganglionic segment may be advantageous, without increasing risk for enterocolitis. Tailored surgical treatment and rehabilitation programmes may prevent mortality and need for transplantation.

Vascular rehabilitation in children with chronic intestinal failure reduces the risk of central-line associated bloodstream infections and catheter replacements

BACKGROUND & AIMS

Children with chronic intestinal failure (IF) require a long-term central venous catheter (CVC) for provision of parenteral nutrition. Vascular, mechanical and infectious complications such as central line-associated bloodstream infections (CLABSI) may lead to progressive loss of venous access sites. Handling and management of CVCs therefore play an important role. Our vascular rehabilitation concept (VRC) is a core component of our intestinal rehabilitation program (IRP) and consists of an education program, optimization of skin care, catheter fixation and lock solution, and the use of hybrid technique for catheter placement. Aim of this study is to analyse the effectiveness of our VRC on CLABSI rates and need for CVC replacements.

METHODS

Retrospective analysis of all children treated in our IRP that were followed up between 2018 and 2023.

RESULTS

A total of 117 children with chronic IF could be included for analysis of 248864 catheter days (CD). 91 patients were referred from other hospitals (127117 CD before and 89359 CD after entry into our IRP). Children receiving primary care at our IRP (32388 CD) showed a significantly lower CLABSI and line replacement rate than patients referred from external centers (p < 0.001). After entering our IRP, CLABSI rates and need for CVC replacements per 1000 CD decreased significantly in referred patients: 1.19 to 0.26 and 1.77 to 0.59, respectively (p < 0.001).

CONCLUSION

Management of paediatric chronic IF patients by an IRP with a vascular rehabilitation concept significantly lowers the rate of CLABSI episodes and the need for catheter replacements.

Dynamic establishment and maintenance of the human intestinal B cell population and repertoire following transplantation in a pediatric-dominated cohort

Introduction

It is unknown how intestinal B cell populations and B cell receptor (BCR) repertoires are established and maintained over time in humans. Following intestinal transplantation (ITx), surveillance ileal mucosal biopsies provide a unique opportunity to map the dynamic establishment of recipient gut lymphocyte populations in immunosuppressed conditions.

Methods

Using polychromatic flow cytometry that includes HLA allele group-specific antibodies distinguishing donor from recipient cells along with high throughput BCR sequencing, we tracked the establishment of recipient B cell populations and BCR repertoire in the allograft mucosa of ITx recipients.

Results

We confirm the early presence of naïve donor B cells in the circulation (donor age range: 1-14 years, median: 3 years) and, for the first time, document the establishment of recipient B cell populations, including B resident memory cells, in the intestinal allograft mucosa (recipient age range at the time of transplant: 1-44 years, median: 3 years). Recipient B cell repopulation of the allograft was most rapid in infant (<1 year old)-derived allografts and, unlike T cell repopulation, did not correlate with rejection rates. While recipient memory B cell populations were increased in graft mucosa compared to circulation, naïve recipient B cells remained detectable in the graft mucosa for years. Comparisons of peripheral and intra-mucosal B cell repertoires in the absence of rejection (recipient age range at the time of transplant: 1-9 years, median: 2 years) revealed increased BCR mutation rates and clonal expansion in graft mucosa compared to circulating B cells, but these parameters did not increase markedly after the first year post-transplant. Furthermore, clonal mixing between the allograft mucosa and the circulation was significantly greater in ITx recipients, even years after transplantation, than in deceased adult donors. In available pan-scope biopsies from pediatric recipients, we observed higher percentages of naïve recipient B cells in colon allograft compared to small bowel allograft and increased BCR overlap between native colon vs colon allograft compared to that between native colon vs ileum allograft in most cases, suggesting differential clonal distribution in large intestine vs small intestine.

Discussion

Collectively, our data demonstrate intestinal mucosal B cell repertoire establishment from a circulating pool, a process that continues for years without evidence of stabilization of the mucosal B cell repertoire in pediatric ITx patients.

Improved Preservation of Rat Small Intestine Transplantation Graft by Introduction of Mesenchymal Stem Cell-Secreted Fractions

Segmental grafts from living donors have advantages over grafts from deceased donors when used for small intestine transplantation. However, storage time for small intestine grafts can be extremely short and optimal graft preservation conditions for short-term storage remain undetermined. Secreted factors from mesenchymal stem cells (MSCs) that allow direct activation of preserved small intestine grafts. Freshly excised Luc-Tg LEW rat tissues were incubated in preservation solutions containing MSC-conditioned medium (MSC-CM). Preserved Luc-Tg rat-derived grafts were then transplanted to wild-type recipients, after which survival, injury score, and tight junction protein expression were examined. Luminance for each graft was determined using in vivo imaging. The findings indicated that 30-100 and 3-10 kDa fractions of MSC-CM have superior activating effects for small intestine preservation. Expression of the tight-junction proteins claudin-3, and zonula occludens-1 preserved for 24 h in University of Wisconsin (UW) solution containing MSC-CM with 50-100 kDa, as shown by immunostaining, also indicated effectiveness. Reflecting the improved graft preservation, MSC-CM preloading of grafts increased survival rate from 0% to 87%. This is the first report of successful transplantation of small intestine grafts preserved for more than 24 h using a rodent model to evaluate graft preservation conditions that mimic clinical conditions.

Indications for Intestinal Transplantation

Outcomes for patients with chronic intestinal failure have improved with organization of experts into multidisciplinary teams delivering care in intestinal rehabilitation programs. There have been improvements in understanding of intestinal failure complications as well as development of newer therapies that have amplified the improvements in survival. In spite of this encouraging trend, patients who fail PN are often referred too late for intestinal transplantation. The author proposes a more rational framework that might allow earlier identification of intestinal failure patients at risk for PN-failure, who could appropriately be considered earlier for intestinal transplantation with improvements in overall outcomes.

Intestinal Transplantation: Include the Spleen with Intestinal Graft?

The traditional procedure for multivisceral transplant (MVT) is to transplant the stomach, pancreas, intestine, and liver en bloc. During surgery, the native spleen is routinely removed from the recipient, and it usually creates more space in the abdomen to insert the allogeneic graft. Thus, recipients often become asplenic after MVT. Considering all of the risks and benefits, we advocate that temporary transplant of the donor spleen could be the best option for MVT recipients; it could potentially reduce the rate of intestinal allograft rejection without increasing the risk for graft-versus-host disease.

Pathophysiology of ascites: The importance of the intestine. A surgical contribution to the understanding of a medical problem

The understanding of the mechanisms for the development of ascites has evolved over the years, involving the liver, peritoneum, heart, and kidneys as key responsible for its formation. In this article, we review the pathophysiology of ascites formation, introducing the role of the intestine as a major responsible for ascites production through "a game changer" case.

From intestinal failure to transplantation: Review on the current need for transplant indications under multidisciplinary transplant programs worldwide

INTRODUCTION

Intestinal failure, defined as the loss of gastrointestinal function to the point where nutrition cannot be maintained by enteral intake alone, presents numerous challenges in children, not least the timing of consideration of intestine transplantation.

OBJECTIVES

To describe the evolution of care of infants and children with intestinal failure including parenteral nutrition, intestine transplantation, and contemporary intestinal failure care.

METHODS

The review is based on the authors' experience supported by an in-depth review of the published literature.

RESULTS

The history of parenteral nutrition, including out-patient (home) administration, and intestine transplantation are reviewed along with the complications of intestinal failure that may become indications for consideration of intestine transplantation. Current management strategies for children with intestinal failure are discussed along with changes in need for intestine transplantation, recognizing the difficulty in generalizing recommendations due to the high level of heterogeneity of intestinal pathology and residual bowel anatomy and function.

DISCUSSION

Advances in the medical and surgical care of children with intestinal failure have resulted in improved transplant-free survival and a significant fall in demand for transplantation. Despite these improvements a number of children continue to fail rehabilitative care and require intestine transplantation as life-saving therapy or when the burden on ongoing parenteral nutrition becomes too great to bear.

Sepsis during short bowel syndrome hospitalizations: Identifying trends, disparities, and clinical outcomes in the United States

BACKGROUND

Short bowel syndrome (SBS) hospitalizations are often complicated with sepsis. There is a significant paucity of data on adult SBS hospitalizations in the United States and across the globe.

AIM

To assess trends and outcomes of SBS hospitalizations complicated by sepsis in the United States.

METHODS

The National Inpatient Sample was utilized to identify all adult SBS hospitalizations between 2005-2014. The study cohort was further divided based on the presence or absence of sepsis. Trends were identified, and hospitalization characteristics and clinical outcomes were compared. Predictors of mortality for SBS hospitalizations complicated with sepsis were assessed.

RESULTS

Of 247097 SBS hospitalizations, 21.7% were complicated by sepsis. Septic SBS hospitalizations had a rising trend of hospitalizations from 20.8% in 2005 to 23.5% in 2014 (P trend < 0.0001). Compared to non-septic SBS hospitalizations, septic SBS hospitalizations had a higher proportion of males (32.8% vs 29.3%, P < 0.0001), patients in the 35-49 (45.9% vs 42.5%, P < 0.0001) and 50-64 (32.1% vs 31.1%, P < 0.0001) age groups, and ethnic minorities, i.e., Blacks (12.4% vs 11.3%, P < 0.0001) and Hispanics (6.7% vs 5.5%, P < 0.0001). Furthermore, septic SBS hospitalizations had a higher proportion of patients with intestinal transplantation (0.33% vs 0.22%, P < 0.0001), inpatient mortality (8.5% vs 1.4%, P < 0.0001), and mean length of stay (16.1 d vs 7.7 d, P < 0.0001) compared to the non-sepsis cohort. A younger age, female gender, White race, and presence of comorbidities such as anemia and depression were identified to be independent predictors of inpatient mortality for septic SBS hospitalizations.

CONCLUSION

Septic SBS hospitalizations had a rising trend between 2005-2014 and were associated with higher inpatient mortality compared to non-septic SBS hospitalizations.

Use of teduglutide in adults with short bowel syndrome-associated intestinal failure

Short bowel syndrome (SBS) is a rare gastrointestinal disorder associated with intestinal failure (SBS-IF) and poor health-related outcomes. Patients with SBS-IF are unable to absorb sufficient nutrients or fluids to maintain significantly metabolic homeostasis via oral or enteral intake alone and require long-term intravenous supplementation (IVS), consisting of partial or total parenteral nutrition, fluids, electrolytes, or a combination of these. The goal of medical and surgical treatment for patients with SBS-IF is to maximize intestinal remnant absorptive capacity so that the need for IVS support may eventually be reduced or eliminated. Daily subcutaneous administration of the glucagon-like peptide 2 analog, teduglutide, has been shown to be clinically effective in reducing IVS dependence and potentially improving the health-related quality of life of patients with SBS-IF. The management of patients with SBS-IF is complex and requires close monitoring. This narrative review discusses the use of teduglutide for patients with SBS-IF in clinical practice. The screening of patient eligibility for teduglutide treatment, initiation, monitoring of efficacy and safety of treatment, adapting or weaning off IVS, and the healthcare setting needed for SBS-IF management are described, taking into consideration data from clinical trials, observational studies, and clinical experience.

Application of enzyme-linked immunosorbent assay to detect antimicrobial peptides in human intestinal lumen

Intestinal transplantation is the definitive treatment for intestinal failure. However, tissue rejection and graft-versus-host disease are relatively common complications, necessitating aggressive immunosuppression that can itself pose further complications. Tracking intraluminal markers in ileal effluent from standard ileostomies may present a noninvasive and sensitive way to detect developing pathology within the intestinal graft. This would be an improvement compared to current assessments, which are limited by poor sensitivity and specificity, contributing to under or over-immunosuppression, respectively, and by the need for invasive biopsies. Herein, we report an approach to reproducibly analyze ileal fluid obtained through stoma sampling for antimicrobial peptide/protein concentrations, reasoning that these molecules may provide an assessment of intestinal homeostasis and levels of intestinal inflammation over time. Concentrations of lysozyme (LYZ), myeloperoxidase (MPO), calprotectin (S100A8/A9) and β-defensin 2 (DEFB2) were assessed using adaptations of commercially available enzyme-linked immunosorbent assays (ELISAs). The concentration of α-defensin 5 (DEFA5) was assessed using a newly developed sandwich ELISA. Our data support that with proper preparation of ileal effluent specimens, precise and replicable determination of antimicrobial peptide/protein concentrations can be achieved for each of these target molecules via ELISA. This approach may prove to be reliable as a clinically useful assessment of intestinal homeostasis over time for patients with ileostomies.

Innovative surgical techniques in the intestine and multivisceral transplant

PURPOSE OF REVIEW

This timely review delves into the evolution of multivisceral transplantation (MVT) over the past six decades underscoring how advancements in surgical techniques and immunosuppression have driven transformation, to provide insight into the historical development of MVT, shedding light on its journey from experimentation to a valuable clinical approach.

RECENT FINDINGS

The review presents contemporary enhancements in surgical methods within the context of intestinal transplantation. The versatility of MVT is emphasized, accommodating diverse organ combinations and techniques. Both isolated intestinal transplantation (IIT) and MVT have seen expanded indications, driven by improved parenteral nutrition, transplantation outcomes, and surgical innovations. Surgical techniques are tailored based on graft type, with various approaches for isolated transplantation. Preservation strategies and ostomy techniques are also covered, along with graft assessment advancements involving donor-specific antibodies.

SUMMARY

This review's findings underscore the remarkable evolution of MVT from experimental origins to a comprehensive clinical practice. The progress in surgical techniques and immunosuppression has broadened the spectrum of patients who can benefit from intestinal transplant, including both IIT and MVT. The expansion of indications offers hope to patients with complex gastrointestinal disorders. The detection of donor-specific antibodies in graft assessment advances diagnostic accuracy, ultimately improving patient outcomes.

Nutrition support considerations in pediatric small bowel transplantation

Enteral autonomy is the primary goal of intestinal failure therapy. Intestinal transplantation (ITx) is an option when enteral autonomy cannot be achieved and management complications become life-threatening. The purpose of this review is to summarize existing medical literature related to nutrition requirements, nutrition status, and nutrition support after pediatric ITx. Achieving or maintaining adequate growth after intestinal transplant in children can be challenging because of episodes of rejection that require the use of corticosteroids, occurrences of infection that require a reduction or discontinuation of enteral or parenteral support, and fat malabsorption caused by impaired lymphatic circulation. Nutrient requirements should be assessed and modified regularly based on nutrition status, growth, ventilatory status, wound healing, and the presence of complications. Parenteral nutrition (PN) should be initiated as a continuous infusion early postoperatively. Enteral support should be initiated after evidence of graft bowel function and in the absence of clinical complications. Foods high in simple carbohydrates should be limited, as consumption may result in osmotic diarrhea. Short-term use of a fat-free diet followed by a low-fat diet may reduce the risk of the development of chylous ascites. Micronutrient deficiencies and food allergies are common occurrences after pediatric ITx. Enteral/oral vitamin and mineral supplementation may be required after PN is weaned. Nutrition management of children after ITx can be challenging for all members of the healthcare team. Anthropometric parameters and micronutrient status should be monitored regularly so that interventions to promote growth and prevent or reverse nutrient deficiencies can be implemented promptly.

Cost-utility analysis of teduglutide compared to standard care in weaning parenteral nutrition support in children with short bowel syndrome

BACKGROUND & AIMS

A growing proportion of children with short bowel syndrome (SBS) remain dependent on long-term parenteral nutrition (PN). Teduglutide offers the potential for more children to decrease PN support and achieve enteral autonomy (EA), but at a significant expense. This study aims to assess the incremental costs of teduglutide plus standard of care compared to standard of care alone in weaning PN support per quality-adjusted life year (QALY) gained in children with SBS.

METHODS

This is a cost-utility analysis comparing teduglutide with standard of care alone in children with SBS. A microsimulation model of children with SBS on PN aged 1-17 years was constructed over a time horizon of six years, with a cycle length of one month. The study adopted the healthcare system and societal payer perspectives in Ontario, Canada. The health outcome measure was QALYs, with results expressed in terms of incremental costs and QALYs. Scenario analyses were performed to examine the effects of different time horizons, timing of teduglutide initiation, and modeling cost of teduglutide based on pediatric weight-dosing.

RESULTS

Incremental healthcare system costs for teduglutide compared to standard of care were CAD$441,314 (95% CI, 414,006 to 441,314) and incremental QALYs were 1.80 (95% CI, 1.70 to 1.89) resulting in an incremental cost-effectiveness ratio (ICER) of CAD$285,334 (95% CI, 178,209 to 392,459) per QALY gained. Incremental societal costs were CAD$418,504 (95% CI, 409,487 to 427,522) and incremental societal QALYs were 1.91 (95% CI, 1.85 to 1.98) resulting in an ICER of CAD$261,880 (95% CI, 136,887 to 386,874) per QALY gained. Scenario analysis showed that teduglutide was cost-effective when it was started two years after intestinal resection (ICER CAD$48,741, 95% CI, 17,317 to 80,165) and when its monthly cost was adjusted using weight-based dosing, avoiding wastage of the remaining 5 mg dose vial (Teduglutide dominated over SOC as the less costly and most effective strategy).

CONCLUSIONS

Although teduglutide was not cost-effective in weaning PN support in children with SBS, starting teduglutide once natural intestinal adaptation is reduced and adjusting its monthly cost to reflect cost by volume as dictated by weight-based dosing rendered the intervention cost-effective relative to standard of care. These results indicate the potential for clinicians to re-assess optimal time for initiation of teduglutide after intestinal resection, drug manufacturers to consider the use of multi-dose or paediatric-dose vials, and the opportunity for decision-makers to re-evaluate teduglutide funding.

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.

Dynamic establishment and maintenance of the human intestinal B cell population and repertoire following transplantation

It is unknown how intestinal B cell populations and B cell receptor (BCR) repertoires are established and maintained over time in humans. Following intestinal transplantation (ITx), surveillance ileal mucosal biopsies provide a unique opportunity to map the dynamic establishment of gut lymphocyte populations. Using polychromatic flow cytometry that includes HLA allele group-specific mAbs distinguishing donor from recipient cells along with high throughput BCR sequencing, we tracked the establishment of recipient B cell populations and BCR repertoire in the allograft mucosa of ITx recipients. We confirm the early presence of naïve donor B cells in the circulation and, for the first time, document the establishment of recipient B cell populations, including B resident memory cells, in the intestinal allograft mucosa. Recipient B cell repopulation of the allograft was most rapid in infant (<1 year old)-derived allografts and, unlike T cell repopulation, did not correlate with rejection rates. While recipient memory B cell populations were increased in graft mucosa compared to circulation, naïve recipient B cells remained detectable in the graft mucosa for years. Comparisons of peripheral and intra-mucosal B cell repertoires in the absence of rejection revealed increased BCR mutation rates and clonal expansion in graft mucosa compared to circulating B cells, but these parameters did not increase markedly after the first year post-transplant. Furthermore, clonal mixing between the allograft mucosa and the circulation was significantly greater in ITx recipients, even years after transplantation, than in healthy control adults. Collectively, our data demonstrate intestinal mucosal B cell repertoire establishment from a circulating pool, a process that continues for years without evidence of establishment of a stable mucosal B cell repertoire.

Outcome After Intestinal Transplantation From Living Versus Deceased Donors: A Propensity-matched Cohort Analysis of the International Intestinal Transplant Registry

OBJECTIVE

To describe the worldwide experience with living donation (LD) in intestinal transplantation (ITx) and compare short-term and long-term outcomes to a propensity-matched cohort of deceased donors.

BACKGROUND

ITx is a rare life-saving procedure for patients with complicated intestinal failure (IF). Living donation (LD)-ITx has been performed with success, but no direct comparison with deceased donation (DD) has been performed. The Intestinal Transplant Registry (ITR) was created in 1985 by the Intestinal Transplant Association to capture the worldwide activity and promote center's collaborations.

METHODS

Based on the ITR, 4156 ITx were performed between January 1987 and April 2019, of which 76 (1.8%) were LD, including 5 combined liver-ITx, 7 ITx-colon, and 64 isolated ITx. They were matched with 186 DD-ITx for recipient age/sex, weight, region, IF-cause, retransplant, pretransplant status, ABO compatibility, immunosuppression, and transplant date. Primary endpoints were acute rejection and 1-/5-year patient/graft survival.

RESULTS

Most LDs were performed in North America (61%), followed by Asia (29%). The mean recipient age was: 22 years; body mass index: 19kg/m²; and female/male ratio: 1/1.4. Volvulus (N=17) and ischemia (N=17) were the most frequent IF-causes. Fifty-two percent of patients were at home at the time of transplant. One-/5-year patient survival for LD and DD was 74.2/49.8% versus 80.3/48.1%, respectively ( P =0.826). One-/5-year graft survival was 60.3/40.6% versus 69.2/36.1%, respectively ( P =0.956). Acute rejection was diagnosed in 47% of LD versus 51% of DD ( P =0.723).

CONCLUSION

Worldwide, LD-ITx has been rarely performed. This retrospective matched ITR analysis revealed no difference in rejection and in patient/graft survival between LD and DD-ITx.

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.

Application of Intestinal Barrier Molecules in the Diagnosis of Acute Cellular Rejection After Intestinal Transplantation

Diagnosing acute rejection after intestinal transplantation currently heavily relies on histopathological analysis of graft biopsies. However, the invasive risks associated with ileoscopic examination and the inaccessibility for biopsy after ileostomy closure hinder real-time detection of rejection responses. Molecules comprising the intestinal barrier have been identified as physiological and molecular biomarkers for various bowel conditions and systemic diseases. To investigate the potential of barrier function-related molecules in diagnosing rejection after intestinal transplantation, plasma samples were collected longitudinally from transplant recipients. The samples were categorized into "indeterminate for rejection (IND)" and "acute rejection (AR)" groups based on clinical diagnoses at each time point. The longitudinal association between plasma levels of these barrier function-related molecules and acute rejection was analyzed using the generalized estimating equations (GEE) method. Logistic GEE models revealed that plasma levels of claudin-3, occludin, sIgA, and zonulin were independent variables correlated with the clinical diagnosis of acute rejection. The subsequent prediction model demonstrated moderate ability in discriminating between IND and AR samples, with a sensitivity of 76.0%, specificity of 89.2%, and accuracy of 84.6%. In conclusion, monitoring plasma levels of claudin-3, occludin, sIgA, and zonulin shows great potential in aiding the diagnosis of acute rejection after intestinal transplantation.

In Vivo Regeneration of Tubular Small Intestine With Motility: A Novel Approach by Orthotopic Transplantation of Decellularized Scaffold

BACKGROUND

Whole-intestine engineering can provide a therapeutic alternative to bowel transplantation. Intestinal components including the mucosa, muscular layer, enteric nervous system, and vasculature must be reestablished as a tubular organ to generate an artificial small intestine. This study proposes a novel approach to produce a transplantable, well-organized tubular small intestine using a decellularized scaffold.

METHODS

Male Lewis rat intestines were used to generate decellularized scaffolds. Patch or tubular grafts were prepared from the decellularized intestine and transplanted into the rat intestine orthotopically. Histological analysis of the decellularized intestine was performed up to 12 wk after transplantation.

RESULTS

Histological examination revealed abundant vascularization into the decellularized patch graft 1 wk after transplantation. Muscular and nervous components, as well as cryptogenesis, were observed in the decellularized patch graft 2 wk after transplantation. Sixteen of the 18 rats survived with normal intake of food and water after the decellularized tubular graft transplantation. Compared with silicone tube grafts, the decellularized tubular grafts significantly promoted the infiltration and growth of intestinal components including the mucosa, muscular layer, and nerve plexus from the recipients. Circular and longitudinal muscle with a well-developed myenteric plexus was regenerated, and intestinal motility was confirmed in the decellularized tubular graft 12 wk after transplantation.

CONCLUSIONS

Orthotopic transplantation of decellularized intestine enhanced the reconstruction of the well-organized tubular small intestine with an enteric nervous system in vivo. Our method using a decellularized scaffold represents a promising approach toward whole-intestine engineering and provides a therapeutic alternative for the irreversible intestinal failure.

Intestinal and Multivisceral Transplantation: Indications and Surgical Techniques

Intestinal transplantation and multivisceral transplantation are technically challenging and complex procedures mainly performed on patients with irreversible and non-medically manageable end-stage intestinal failure. Increasingly, other organs besides small intestines are included in the allograft for which the terms "composite intestinal transplantation" and "multivisceral transplantation" are used. Commonly, complex vascular reconstructions are used for these procedures. Knowledge of surgical anatomy hence is essential for accurate interpretation of postoperative imaging in these patients. This article reviews the indications and most common surgical techniques for intestinal and multivisceral transplantations.

Intestinal Donation and Utilization: Single-Center Analysis Within Eurotransplant

Intestinal donor criteria are classically kept strict, thereby limiting donor supply. Indications for intestinal transplantation (ITx) are rare, but improved outcome and new emerging indications lead to increased demand and relaxing donor criteria should be considered. We sought to compare the donor criteria of intestines transplanted at our center with predefined (per protocol) criteria, and to determine how relaxing donor criteria could impact the potential donor pool. Donor criteria used in 22 consecutive ITx at our center between 2000 and 2020 were compared with predefined criteria. Next, multiorgan donors effectively offered by our Donor Network to Eurotransplant between 2014 and 2020 were retrospectively screened, according to predefined and effectively used intestinal donation criteria. Finally, utilization rate of offered intestines was calculated. In our ITx series, the effectively used donor criteria were less strict than those initially predefined. With these relaxed criteria, a favorable 5-year graft/patient survival of 75% and 95%, respectively was reached. Applying these relaxed criteria would lead to a 127% increase in intestinal offers. Paradoxically, 70% of offered intestines were not used. In conclusion, a significant increase in intestinal donation could be obtained by relaxing donor criteria, while still achieving excellent outcome. Offered intestines are underutilized.

Pediatric intestine and multivisceral transplant

PURPOSE OF REVIEW

Intestinal and multivisceral transplantation (ITx, MVTx) is the cornerstone in treatment of irreversible intestinal failure (IF) and complications related to parenteral nutrition. This review aims to highlight the unique aspects of the subject in pediatrics.

RECENT FINDINGS

Etiology of intestinal failure (IF) in children shares some similarity with adults but several unique considerations when being evaluated for transplantation will be discussed. Owing to significant advancement in IF management and home parenteral nutrition (PN), indication criteria for pediatric transplantation continues to be updated. Outcomes have continued to improve with current long-term patient and graft survival in multicenter registry reports reported at 66.1% and 48.8% at 5 years, respectively. Pediatric specific surgical challenges such abdominal closure, post transplantation outcomes, and quality of life are discussed in this review.

SUMMARY

ITx and MVTx remain lifesaving treatment for many children with IF. However long-term graft function is still a major challenge.

Pediatric Intestinal Pseudo-Obstruction: An International Survey on Diagnostic and Management Strategies in the European Reference Network for Rare Inherited and Congenital Anomalies Intestinal Failure Teams

OBJECTIVES

Pediatric intestinal pseudo-obstruction (PIPO) management is based on nutritional, medical, and surgical care while available evidence is scarce. The aim of this study was to outline the current diagnostic and management strategies in intestinal failure (IF) teams of the European Reference Network for rare Inherited and Congenital Anomalies (ERNICA) and to compare these practices to the latest PIPO international guidelines.

METHODS

An online survey on institutional diagnostic and management strategies of PIPO was conducted among the ERNICA IF teams.

RESULTS

In total, 11 of 21 ERNICA IF centers from 8 countries participated. On average, 64% of teams had ≥6 and 36% had 1-5 PIPO patients under active follow-up. In total, 80 of 102 PIPO patients were parenteral nutrition (PN) dependent while each IF team had median 4 (range 0-19) PN dependent PIPO patients under follow-up. On average, each center received 1-2 new PIPO patients per year. Diagnostics mostly followed current guidelines while medical and surgical management strategies were diverse.

CONCLUSIONS

Numbers of PIPO patients are low and management strategies are diverse among ERNICA IF teams. To improve PIPO patient care, regional reference centers with specialized multidisciplinary IF teams and continuous collaboration across centers are needed.

A nordic multicenter study on contemporary outcomes of pediatric short bowel syndrome in 208 patients

BACKGROUND & AIMS

Despite advances in the management of short bowel syndrome related intestinal failure (SBS-IF), large-scale contemporary pediatric studies are scarce. The aim of this multicenter study was to assess key outcomes and clinical prognostic factors in a recent Nordic pediatric SBS-IF population.

METHODS

Patients with SBS-IF treated during 2010-2019, whose parenteral support (PS) started at age <1 year and continued >60 consecutive days were included and retrospectively reviewed. All six participating centers followed multidisciplinary SBS-IF management. Risk factors for PS dependency, intestinal failure associated liver disease (IFALD) and mortality were assessed with Cox regression and Kaplan Meier analyses. IFALD was defined with serum liver biochemistry levels.

RESULTS

Among 208 patients, SBS-IF resulted from NEC in 49%, gastroschisis w/wo atresia in 14%, small bowel atresia in 12%, volvulus in 11%, and other diagnoses in 14%. Median age-adjusted small bowel length was 43% (IQR 21-80%). After median follow up of 4.4 years (IQR 2.5-6.9), enteral autonomy was reached by 76%, none had undergone intestinal transplantation, and overall survival was 96%. Half of deaths (4/8) were caused by septic complications. Although biochemical cholestasis occurred only in 3% at latest follow-up and none of deaths were directly caused by IFALD, elevated liver biochemistry (HR 0.136; P = 0.017) and shorter remaining small bowel (HR 0.941; P = 0.040) predicted mortality. Shorter remaining small bowel and colon, and presence of end-ostomy were the main predictors of PS dependency, but not IFALD. Patients with NEC reached enteral autonomy more efficiently and had decreased incidence of IFALD compared to other etiologies.

CONCLUSIONS

Although with current multidisciplinary management, prognosis of pediatric SBS is encouraging, septic complications and IFALD still associated with the remaining low mortality rate.

Small bowel transplant - novel indications and recent progress

INTRODUCTION

Advances in the management of intestinal failure have led to a reduction in the number of intestinal transplants. The number of bowel transplants has been mainly stable even though a slight increase has been observed in the last 5 years.

AREAS COVERED

Standard indication includes patients with a reasonable life expectancy. Recent progress can be deduced by the increased number of intestine transplants in adults: this is due to the continuous improvement of 1-year graft survival worldwide (without differences in 3- and 5-year) associated with better abdominal wall closure techniques. This review aims to provide an update on new indications and changes in trends of pediatric and adult intestine transplantation. This analysis, which stretches through the past 5 years, is based on a collection of related manuscripts from PubMed.

EXPERT COMMENTARY

Intestinal transplants should be solely intended for a group of individuals for whom indications for transplantation are clear and both medical and surgical rehabilitations have failed. Nevertheless, many protocols developed over the years have not yet solved the key question represented by the over-immunosuppression. Novel indications and recent progress in the bowel transplant field, minimal yet consistent, represent a pathway to be followed.

Pediatric intestinal rehabilitation

PURPOSE OF REVIEW

The intestinal rehabilitation program (IRP) is a comprehensive treatment strategy that employs various approaches implemented by multidisciplinary teams to treat intestinal failure in children. This program has shown promising results, such as reducing complications and improving prognosis and quality of life (QOL). In this review, we discuss the current status of this program and relevant topics.

RECENT FINDINGS

IRP includes the prevention and treatment of various complications such as intestinal failure associated liver disease, catheter-related bloodstream infection or sepsis, and venous thromboembolism. In addition, treatment strategies such as glucagon-like peptide-2 analogs, surgical interventions, and intestinal transplantation have evolved over time and have contributed to improved outcomes. In addition, the scope and regions for IRP activities have expanded.

SUMMARY

IRP improves the prognosis and QOL of children with intestinal failure. The development of new drugs, surgical methods, and treatment strategies is expected to improve the current and future status of pediatric patients with intestinal failure. Furthermore, international institutions must collaborate, share knowledge, conduct joint research, and establish patient registries to advance IRP progress.

Congenital Tufting Enteropathy, a Rare Cause of Diarrhea and Malnourishment in Arab Child with Genetic and Histopathology Investigations

Congenital tufting enteropathy (CTE), also known as intestinal epithelial dysplasia (IED), is a rare autosomal recessive disorder due to EPCAM gene mutation. It is a rare congenital enteropathy that presents in early infancy as an intractable diarrhea that is independent of breast formula feeding that requires life-long total parental nutrition (TPN) to acquire adequate calories and fluid intake or small bowel transplantation in severe cases. Here, we report a case of intestinal failure due to congenital tufting enteropathy in a 3-year-old girl who presented with loose stools and failure to thrive. This study aims to review the literature about CTE and discuss the clinicopathological aspects and to be able to distinguish it from other causes of congenital diarrheal disorders (CDDs).

Long-term survival following fungal catheter-related bloodstream infection for patients with intestinal failure receiving home parenteral support

BACKGROUND

A fungal-related catheter-related bloodstream infection (CRBSI) is less frequent than those induced by bacteria. In the past, a single episode of fungal CRBSI has been used as a marker of home parenteral nutrition (HPN) failure and thus a possible indication for intestinal transplantation.

METHODS

Survival outcomes were assessed from a prospectively maintained database of patients initiated on HPN for underlying chronic intestinal failure between 1993 and 2018, with a censoring date of December 31, 2020. Cox regression was performed to assess predictors of mortality with univariable and multivariable analysis.

RESULTS

A total of 1008 patients were included in the study, with a total of 1 364 595 catheter days. There were 513 CRBSI events recorded in 262 patients, equating to a CRBSI rate of 0.38/1000 catheter days. A total of 38/262 (14.5%) patients had at least one episode of fungal CRBSI, whereas 216/262 (82.4%) had at least one bacterial but no fungal CRBSI. The median time between HPN initiation and the first CRBSI episode was 20.6 months (95% confidence interval, 16.5-24.1). Episodes of fungal or bacterial CRBSI and the number of CRBSI episodes were not associated with increased mortality. Overall, 15 CRBSI-related deaths were observed in the observation period (0.01 CRBSI deaths/1000 catheter days), two of these were fungal in origin.

CONCLUSION

The occurrence of a fungal CRBSI does not increase the risk of death compared with patients who have bacterial CRBSI or those without a CRBSI event.

Management of Short Bowel Syndrome (SBS) and Intestinal Failure

Short bowel syndrome (SBS) is a chronic disease whose natural history requires a changing array of management strategies over time. Chief amongst these is the chronic use of parenteral nutrition (PN) to ensure adequate nutritional intake. With time and appropriate management, approximately half of all SBS patients will successfully regain a functional, baseline level of intrinsic bowel function that will allow for them to achieve PN independence. However, the other half of SBS patients will progress into chronic intestinal failure which warrants a change in therapy to include more aggressive medical and potentially surgical measures. This review examines the evolving treatment strategies involved in the management of SBS as well as intestinal failure.

Standardised survival and excess Life Years Lost in patients with type 3 intestinal failure

BACKGROUND & AIMS

Long term outcomes have been reported in home parenteral nutrition (HPN)-dependent patients with type 3 intestinal failure (IF), but there are limited survival data standardised to the general population that would help provide a meaningful prognosis for patients and clinicians. The primary aim of this study was therefore to investigate the survival of HPN-dependent patients and to evaluate the specific impact of type 3 IF on their life expectancy standardised to that of the general population.

METHODS

This was a cohort study of adult patients initiated on HPN between 1978 and 2018 at a national UK IF reference centre and followed up until death or censoring date of 31st December 2020. The standardised mortality ratio (SMR) was calculated as observed deaths divided by expected deaths using UK Office for National Statistics database. Excess Life Years Lost (LYL) were calculated separately for each sex as the differences in average life expectancy between patients with type 3 IF and the general population. Survival data were evaluated using cox regression models adjusting for confounding.

RESULTS

In total, 1046 patients were identified, with a total observation time of 7344.1 patient-years. Patients with malignancy (n = 206) were excluded from the survival analysis. Of the remaining 840 patients, 398 were alive by the end of follow-up. The probability of survival was 91.8% at 1 year, 69.3% at 5 years, 54.3% at 10 years, 29.8% at 20 years and 16.7% at 30 years. Patients who did not achieve nutritional autonomy had an increased likelihood of death compared to patients who ceased HPN. In total, 40 (9.0%) deaths were HPN or IF-related, while underlying disease leading to IF accounted for 98 (22.2%) deaths. There were 270 (61.1%) deaths not related to IF, with the majority of these patients dying from infections unrelated to HPN. Overall mortality rates were higher among patients with a diagnosis of type 3 IF compared with the general UK population with a SMR of 7.48 (95% CI 6.80 to 8.21) and an excess mortality rate of 54.0 per 1000 person-years. All mechanisms of IF were associated with excess mortality, with SMR ranging from 6.82 (95% CI 5.98 to 7.72) for short bowel syndrome to 15.51 (95% CI 11.73 to 20.03) for dysmotility. On average, the excess LYL was 17.45 years for males and 17.39 years for females compared with the general population of the same age.

CONCLUSION

This the largest single-centre series reporting survival outcomes in patients with type 3 IF over more than a four-decade period and the first to report LYL in this patient cohort. Type 3 IF was associated with more than seven-fold higher mortality rates than for the general UK population and shorter life expectancies of more than 17 years. Survival, however, was better in those able to achieve nutritional autonomy. Since the majority of deaths were due to non-HPN or non-IF causes, there is clearly a need now to further explore these causes of death in order to improve our understanding of excessive mortality in type 3 IF and develop ways to prevent it.

An international multicenter validation study of the Toronto listing criteria for pediatric intestinal transplantation

Deciding which patients would benefit from intestinal transplantation (IT) remains an ethical/clinical dilemma. New criteria* were proposed in 2015: ≥2 intensive care unit (ICU) admissions, loss of ≥3 central venous catheter (CVC) sites, and persistently elevated conjugated bilirubin (CB ≥ 75 μmol/L) despite 6 weeks of lipid modification strategies. We performed a retrospective, international, multicenter validation study of 443 children (61% male, median gestational age 34 weeks [IQR 29-37]), diagnosed with IF between 2010 and 2015. Primary outcome measure was death or IT. Sensitivity, specificity, NPV, PPV, and probability of death/transplant (OR, 95% confidence intervals) were calculated for each criterion. Median age at IF diagnosis was 0.1 years (IQR 0.03-0.14) with median follow-up of 3.8 years (IQR 2.3-5.3). Forty of 443 (9%) patients died, 53 of 443 (12%) were transplanted; 11 died posttransplant. The validated criteria had a high predictive value of death/IT; ≥2 ICU admissions (p < .0001, OR 10.2, 95% CI 4.0-25.6), persistent CB ≥ 75 μmol/L (p < .0001, OR 8.2, 95% CI 4.8-13.9). and loss of ≥3 CVC sites (p = .0003, OR 5.7, 95% CI 2.2-14.7). This large, multicenter, international study in a contemporary cohort confirms the validity of the Toronto criteria. These validated criteria should guide listing decisions in pediatric IT.

Immunosuppression Regimens for Intestinal Transplantation in Children

Pediatric intestinal transplant serves as the only definitive treatment for children with irreversible intestinal failure. Successful intestinal transplant hinges upon appropriate management of immunosuppression. The indications for intestinal transplant have changed over time. Immunosuppression regimens can be divided into induction and maintenance phases along with treatment of acute rejection. Intestinal transplant induction now often includes antithymocyte globulin or basiliximab in addition to corticosteroids. Maintenance regimens continue to be dominated by tacrolimus, with additional agents used to either decrease goal tacrolimus levels to limit toxicity or as an adjunct in sensitized patients. Careful monitoring can help to limit serious complications, such as rejection, infection, and malignancy. Future work will aim to decrease variation in practice and identify methods to determine optimal immunosuppression for a particular patient. Furthermore, there is a need for non-invasive monitoring of the intestinal graft and functional assessments of immunosuppression.

Innovations in Immunosuppression for Intestinal Transplantation

It has been 57 years since the first intestinal transplant. An increased incidence of graft rejection has been described compared to other solid organ transplants due to high immunogenicity of the bowel, which in health allows the balance between of dietary antigen with defense against pathogens. Expanding clinical experience, knowledge of gastrointestinal physiology and immunology have progress post-transplant immunosuppressive drug regimens. Current regimes aim to find the window between prevention of rejection and the risk of infection (the leading cause of death) and malignancy. The ultimate aim is to achieve graft tolerance. In this review we discuss advances in mucosal immunology and technologies informing the development of new anti-rejection strategies with the hope of improved survival in the next generation of transplant recipients.

Pediatric intestinal transplantation

Advancements in donor management, organ preservation and operative techniques, as well as immunosuppressive therapies, have provided children with intestinal failure and its complications a chance not only for enteral autonomy but also long-term survival through intestinal transplantation (ITx). First described in the 1960's, experience has grown in managing these complex patients both pre- and post-transplant. The goals of this review are to provide a brief history of intestinal transplantation and intestinal rehabilitation in pediatric patients, followed by focused discussions of the indications for ITx, induction and maintenance immunosuppression therapies, common post-operative complications, and outcomes/quality of life post-transplant.

Management of pediatric intestinal failure related to short bowel syndrome

Intestinal failure (IF) secondary to short bowel syndrome is a challenging and complex medical condition with significant risk for surgical and medical complications. Significant advancements in the care of this patient population have led to improved survival rates. Due to their intensive medical needs children with IF are at risk for long-term complications that require comprehensive management and close monitoring. The purpose of this paper is to review the available literature emphasizing the surgical aspects of care for children with IF secondary to short bowel syndrome. A key priority in the surgical care of this patient population includes strategies to preserve available bowel and maximize its function. Utilization of novel surgical techniques and autologous bowel reconstruction can have a significant impact on children with IF secondary to short bowel syndrome related to the function of their bowel and ability to achieve enteral autonomy. It is also important to understand the potential long-term complications to ensure strategies are put in place to mitigate risk with early detection to improve long-term outcomes.

Difficult Vascular Access in Children with Short Bowel Syndrome: What to Do Next?

Short Bowel Syndrome and intestinal failure are chronic and severe conditions that may require life-long parenteral nutrition in children. Survival of these children rely on the correct functioning of central venous catheters; therefore, careful management, prevention, and treatment of complications is of paramount importance. Despite a growing awareness of preserving the vascular real estate, a certain number of patients still experience a progressive and life-threatening exhaustion of vascular access. We searched the literature to highlight the current management of children with vascular exhaustion, specifically focusing on vascular access salvage strategies and last-resource alternative routes to central veins. Given the paucity of data, results are reported in the form of a narrative review.

Chronic Intestinal Failure in Children: An International Multicenter Cross-Sectional Survey

Background: The European Society for Clinical Nutrition and Metabolism database for chronic intestinal failure (CIF) was analyzed to investigate factors associated with nutritional status and the intravenous supplementation (IVS) dependency in children. Methods: Data collected: demographics, CIF mechanism, home parenteral nutrition program, z-scores of weight-for-age (WFA), length or height-for-age (LFA/HFA), and body mass index-for-age (BMI-FA). IVS dependency was calculated as the ratio of daily total IVS energy over estimated resting energy expenditure (%IVSE/REE). Results: Five hundred and fifty-eight patients were included, 57.2% of whom were male. CIF mechanisms at age 1−4 and 14−18 years, respectively: SBS 63.3%, 37.9%; dysmotility or mucosal disease: 36.7%, 62.1%. One-third had WFA and/or LFA/HFA z-scores < −2. One-third had %IVSE/REE > 125%. Multivariate analysis showed that mechanism of CIF was associated with WFA and/or LFA/HFA z-scores (negatively with mucosal disease) and %IVSE/REE (higher for dysmotility and lower in SBS with colon in continuity), while z-scores were negatively associated with %IVSE/REE. Conclusions: The main mechanism of CIF at young age was short bowel syndrome (SBS), whereas most patients facing adulthood had intestinal dysmotility or mucosal disease. One-third were underweight or stunted and had high IVS dependency. Considering that IVS dependency was associated with both CIF mechanisms and nutritional status, IVS dependency is suggested as a potential marker for CIF severity in children.

Spectrum of Interventional Procedures During Hybrid Central Line Placement in Pediatric Intestinal Rehabilitation Patients With End-Stage Vascular Access

Background

Loss of available central vein access sites for parenteral nutrition delivery represents one of the main indications for intestinal transplantation in children with intestinal failure. Placement of central venous catheters can be challenging in advanced loss of patent venous pathways. We recently described the hybrid technique (interventional plus surgical approach) of central line placement in children. The aim of this study was to describe and analyze the interventions used during the hybrid procedures regarding feasibility, safety and outcome.

Methods

We retrospectively analyzed the course of all children in our intestinal rehabilitation program undergoing hybrid central line placement. We evaluated patients' conditions, interventional techniques and surgical peculiarities as well as outcome.

Results

203 children were treated in our intestinal rehabilitation program between 2010 and 2021. Due to loss of venous access, hybrid technique was performed in 53 children during 76 interventions. In 40 cases the same vessel was reused via Seldinger technique. Among the 30 ultrasound-guided new vessel punctures, 12 were performed by puncture of collateral vessels. Extended interventions due to thoracic central venous obstruction and/or thrombosis requiring additional access via a femoral vein for rehabilitation of the vascular system was performed during 29 procedures including catheter extraction (1), angioplasties (18), stent placement (1), revascularization (5) and thrombectomy (4). Placement of a central line was not possible in 6 children which eventually underwent extended thoracic/vascular surgery: in three children the previously placed catheter could not be removed, in one child, placement of a thrombectomy-catheter was not possible because of inferior vena cava occlusion, and in two children, revascularization failed. Intestinal transplantation was considered in one patient because of impending loss of vascular access. Two self-limiting minor extravasations and one intervention-associated pericardial effusion occurred.

Conclusions

Hybrid interventions for central venous catheter placement and vascular rehabilitation enable a high success rate in children with intestinal failure and end-stage vascular access, circumventing the need for intestinal transplantation or advanced surgery. The relevant procedures are complex and require a foresighted and individualized approach with a wide range of interventional techniques. If performed with expertise, this combined interventional/surgical approach is feasible and safe.

Potential options to expand the intestinal donor pool: a comprehensive review

PURPOSE OF REVIEW

Intestinal donation is currently restricted to 'perfect' donors, as the intestine is extremely vulnerable to ischemia. With generally deteriorating donor quality and increasing indications for intestinal transplantation (ITx), the potential to safely increase the donor pool should be evaluated.

RECENT FINDINGS

Increasing awareness on intestinal donation (often forgotten) and cautiously broadening the strict donor criteria (increasing age, resuscitation time and ICU stay) could expand the potential donor pool. Donors after circulatory death (DCD) have so far not been considered for ITx, due to the particularly detrimental effect of warm ischemia on the intestine. However, normothermic regional perfusion might be a well tolerated strategy to render the use of DCD intestinal grafts feasible. Furthermore, machine perfusion is under continuous development and might improve preservation of the intestine and potentially offer a platform to modulate the intestinal graft. Lastly, living donation currently represents only a minority of all ITxs performed worldwide. Various studies and registry analysis show that it can be performed safely for the donor and successfully in the recipient.

SUMMARY

Several potential strategies are available to expand the current intestinal donor pool. Most of them require further investigation or technical developments before they can be implemented in the clinical routine.

Multidrug-resistant organisms: A significant cause of severe sepsis in pediatric intestinal and multi-visceral transplantation

Severe sepsis in immunocompromised children is associated with increased mortality. This paper describes the epidemiology landscape, clinical acuity, and outcomes for severe sepsis in pediatric intestinal (ITx) and multi-visceral (MVTx) transplant recipients requiring admission to the pediatric intensive care unit (PICU). Severe sepsis episodes were retrospectively reviewed in 51 ITx and MVTx patients receiving organs between 2009 and 2015. Twenty-nine (56.8%) patients had at least one sepsis episode (total of 63 episodes) through December 2016. Bacterial etiologies accounted for 66.7% of all episodes (n = 42), occurring a median of 122.5 days following transplant (IQR 59-211.8 days). Multidrug-resistant organisms (MDROs) accounted for 73.8% of bacterial infections; extended spectrum beta-lactamase producers, vancomycin-resistant enterococcus, and highly-resistant Pseudomonas aeruginosa were the most commonly identified. Increased mechanical ventilation and vasoactive requirements were noted in MDRO episodes (OR 3.03, 95% CI 1.09-8.46 and OR 3.07, 95% CI 1.09-8.61, respectively; p < .05) compared to non-MDRO episodes. PICU length of stay was significantly increased for MDRO episodes (7 vs. 3 days, p = .02). Graft loss was 24.1% (n = 7) and mortality was 24.1% (n = 7) in patients who experienced severe sepsis. Further attention is needed for MDRO risk mitigation and modification of sepsis treatment guidelines to ensure MDRO coverage for this population.