Current perspectives on pediatric intestinal transplantation

Paediatric intestinal pseudo-obstruction: a scoping review

Paediatric intestinal pseudo-obstruction (PIPO) encompasses a group of rare disorders in which patients present with the clinical features of bowel obstruction in the absence of mechanical occlusion. The management of PIPO presents a challenge as evidence remains limited on available medical and surgical therapy. Parenteral nutrition is often the mainstay of therapy. Long-term therapy may culminate in life-threatening complications including intestinal failure-related liver disease, central line thrombosis and sepsis. Intestinal transplantation remains the only definitive cure in PIPO but is a complex and resource-limited solution associated with its own morbidity and mortality. We conducted a scoping review to present a contemporary summary of the epidemiology, aetiology, pathophysiology, diagnosis, management and complications of PIPO.Conclusion: PIPO represents a rare disorder that is difficult to diagnose and challenging to treat, with significant morbitity and mortality. The only known cure is intestinal transplantation. What is Known: • Paediatric intestinal pseudo-obstruction is a rare, heterogeneous disorder that confers a high rate of morbidity and mortality • Complications of paediatric intestinal pseudo-obstruction include chronic pain, small intestine bacterial overgrowth and malrotation. Other complications can occur related to its management, such as line infections with parenteral nutrition or cardiac side effects of prokinetic medications What is New: • Progress in medical and surgical therapy in recent years has led to improved patient outcomes • Enteral autonomy has been reported in most patients at as early as 1 month post-transplantation.

Severe Late-Onset Acute Cellular Rejection in a Pediatric Patient With Isolated Small Intestinal Transplant Rescued With Aggressive Immunosuppressive Approach: A Case Report

Small intestinal transplantation is performed for patients with intestinal failure who failed other surgical and medical treatment. It carries notable risks, including, but not limited to, acute and chronic cellular rejection and graft malfunction. Late severe acute intestinal allograft rejection is associated with increased risk of morbidity and mortality and, in the majority of cases, ends with total enterectomy. It usually results from subtherapeutic immunosuppression or nonadherence to medical treatment. We present the case of a 20-year-old patient who underwent isolated small bowel transplant for total intestinal Hirschsprung disease at age 7. Due to medication nonadherence, she developed severe late-onset acute cellular rejection manifested by high, bloody ostomy output and weight loss. Ileoscopy showed complete loss of normal intestinal anatomic landmarks and ulcerated mucosa. Graft biopsies showed ulceration and granulation tissue with severe architectural distortion consistent with severe intestinal graft rejection. She initially received intravenous corticosteroids and increased tacrolimus dose without significant improvement. Her immunosuppression was escalated to include infliximab and finally antithymocyte globulin. Graft enterectomy was considered repeatedly; however, clinical improvement was noted eventually with evidence of histologic improvement and salvage of the graft. The aggressive antirejection treatment was complicated by development of post-transplant lymphoproliferative disorder that resolved with reducing immunosuppression. Her graft function is currently maintained on tacrolimus, oral prednisone, and a periodic infliximab infusion. We conclude that a prompt and aggressive immunosuppressive approach significantly increases the chance of rescuing small bowel transplant rejection.

Long-Term Outcomes of Intestinal and Multivisceral Transplantation at a Single Center in Argentina

BACKGROUND

Intestinal failure (IF) patients received parenteral nutrition (PN) as the only available therapy until intestinal transplantation (ITx) evolved as an accepted treatment. The aim of this article is to report the long-term outcomes of a series of ITx performed in pediatric and adult patients at a single center 9 years after its creation.

PATIENTS AND METHODS

This is a retrospective analysis of the ITx performed between May 2006 and January 2015. Diagnoses, pre-ITx mean time on PN, indications for ITx, time on the waiting list for types of ITx, mean total ischemia time, and warm ischemia time, time until PN discontinuation, incidence of acute and chronic rejection, and 5-year actuarial patient survival are reported.

RESULTS

A total of 42 patients received ITx; 80% had short gut syndrome (SG); the mean time on PN was 1620 days. The main indication for ITx was lack of central venous access followed by intestinal failure-associated liver disease (IFALD) and catheter-related infectious complications. The mean time on the waiting list was 188 days (standard deviation, ±183 days). ITx were performed in 26 children and 14 adults. In all, 32 procedures were isolated ITx (IITX); 10 were multiorgan Tx (MOT; 3 combined, 7 multivisceral Tx (MVTx), 1 modified MVTx and 2 with kidney); 2 (4.7 %) were retransplantations: 1 IITx, 1 MVTx, and 5 including the right colon. Thirteen patients (31%) received abdominal rectus fascia. All procedures were performed by the same surgical team. Total ischemia time was 7:53 ± 2:04 hours, and warm ischemia time was 40.2 ± 10.5 minutes. The mean length of implanted intestine was 325 ± 63 cm. Bishop-Koop ileostomy was performed in 67% of cases. In all, 16 of 42 Tx required early reoperations. The overall mean follow-up time was 41 ± 35.6 months. The mean time to PN discontinuation after Tx was 68 days (P = .001). The total number of acute cellular rejection (ACR) episodes until the last follow-up was 83; the total number of grafts lost due to ACR was 4; and the total graft lost due to chronic rejection was 3. At the time of writing, the overall 5-year patient survival is 55% (65% for IITx vs 22% for MOT; P = .0001); 60% for pediatric recipients vs 47% for adults (P = NS); 64% when the indication for ITx was SG vs 25% for non-SG (P = .002).

CONCLUSIONS

At this center, candidates with SG, in the absence of IFALD requiring IITx, showed the best long-term outcomes, independent of recipient age. A multidisciplinary approach is mandatory for the care of intestinal failure patients, to sustain a rehabilitation and transplantation program over time.

Generation of an artificial intestine for the management of short bowel syndrome

PURPOSE OF REVIEW

This article discusses the current state of the art in artificial intestine generation in the treatment of short bowel syndrome.

RECENT FINDINGS

Short bowel syndrome defines the condition in which patients lack sufficient intestinal length to allow for adequate absorption of nutrition and fluids, and thus need parenteral support. Advances toward the development of an artificial intestine have improved dramatically since the first attempts in the 1980s, and the last decade has seen significant advances in understanding the intestinal stem cell niche, the growth of complex primary intestinal stem cells in culture, and fabrication of the biomaterials that can support the growth and differentiation of these stem cells. There has also been recent progress in understanding the role of the microbiota and the immune cells on the growth of intestinal cultures on scaffolds in animal models. Despite recent progress, there is much work to be done before the development of a functional artificial intestine for short bowel syndrome is successfully achieved.

SUMMARY

Continued concerted efforts by cell biologists, bioengineers, and clinician-scientists will be required for the development of an artificial intestine as a clinical treatment modality for short bowel syndrome.

Race affects outcome among infants with intestinal failure

OBJECTIVE

Intestinal failure (IF) is a rare, devastating condition associated with significant morbidity and mortality. We sought to determine whether ethnic and racial differences were associated with patient survival and likelihood of receiving an intestinal transplant in a contemporary cohort of children with IF.

METHODS

This was an analysis of a multicenter cohort study with data collected from chart review conducted by the Pediatric Intestinal Failure Consortium. Entry criteria included infants ≤ 12 months receiving parenteral nutrition (PN) for ≥ 60 continuous days and studied for at least 2 years. Outcomes included death and intestinal transplantation (ITx). Race and ethnicity were recorded as they were in the medical record. For purposes of statistical comparisons and regression modeling, categories of race were consolidated into "white" and "nonwhite" children.

RESULTS

Of 272 subjects enrolled, 204 white and 46 nonwhite children were available for analysis. The 48-month cumulative incidence probability of death without ITx was 0.40 for nonwhite and 0.16 for white children (P < 0.001); the cumulative incidence probability of ITx was 0.07 for nonwhite versus 0.31 for white children (P = 0.003). The associations between race and outcomes remained after accounting for low birth weight, diagnosis, and being seen at a transplant center.

CONCLUSIONS

Race is associated with death and receiving an ITx in a large cohort of children with IF. This study highlights the need to investigate reasons for this apparent racial disparity in outcome among children with IF.

Short bowel syndrome in the NICU

Short bowel syndrome (SBS) is the most common cause of intestinal failure in infants. In neonates and young infants, necrotizing enterocolitis, gastroschisis, intestinal atresia, and intestinal malrotation/volvulus are the leading causes of SBS. Following an acute postsurgical phase, the residual gastrointestinal tract adapts with reorganization of the crypt-villus histoarchitecture and functional changes in nutrient absorption and motility. A cohesive, multidisciplinary approach can allow most neonates with SBS to transition to full enteral feeds and achieve normal growth and development. In this article, the clinical features, management, complications, and prognostic factors in SBS are reviewed.

Recent advances in small bowel diseases: Part II

As is the case in all areas of gastroenterology and hepatology, in 2009 and 2010 there were many advances in our knowledge and understanding of small intestinal diseases. Over 1000 publications were reviewed, and the important advances in basic science as well as clinical applications were considered. In Part II we review six topics: absorption, short bowel syndrome, smooth muscle function and intestinal motility, tumors, diagnostic imaging, and cystic fibrosis.

Living donor intestinal transplant using a standardized technique: first report from India

AIM

We describe the first living donor intestinal transplant (LDIT) in India and discuss the indications and problems of this complex procedure.

METHODS

A 43-year-old male patient required massive bowel resection for gangrene due to thrombosis of the superior mesenteric artery. He was maintained on parenteral nutrition but developed cholestasis and well as repeated catheter related infections with progressive loss of venous access due to thrombosis of central veins. A LDIT was performed using 200 cm of small intestine from the patient's son. The graft was based on the continuation of the superior mesenteric vessels beyond the ileocolic branch. The artery was anastomosed directly to the aorta and the vein to the venacava.

RESULTS

The graft functioned well and he was weaned off parenteral nutrition. However, he later developed complications (wound dehiscence and enterocutaneous fistula) and developed sepsis. He succumbed to sepsis with a functioning graft 6 weeks after the transplant. The donor recovered uneventfully and was discharged on the 4th postoperative day.

CONCLUSIONS

LDIT can be life saving in patients with intestinal failure and failure of parenteral nutrition. There is a need to introduce this modality in India. In a setting of scarcity of deceased donor organs the living donor option has advantages.

Staged abdominal closure after small bowel or multivisceral transplantation

Following paediatric SBMT, size discrepancy between the recipient's abdomen and the graft may lead to ACS, graft dysfunction, and death. We report our experience with SAC in these patients. Between 04/1993 and 03/2009, 57 children underwent 62 SBMTs. When abdominal wall tension seemed excessive for safe PAC, SAC was performed, using a Silastic® sheet and a vacuum occlusive dressing. Transplantations with SAC (23 combined liver and small bowel [CLB]) were compared with those with PAC [14 ISB and 25 CLB]. Indications for transplantation, preoperative status (after stratification for ISB/CLB transplants), age at transplantation, donor-to-recipient weight ratio, reduction in bowel and/or liver, and incidence of wound complications were not different in both groups. Post-operative intubation, stay in intensive care unit, and hospital stay were prolonged after SAC. Two deaths were related to ACS after PAC, none after SAC. Since 2000, one-yr patient survival is 73% after ISB transplantation and 57% vs. 75% after CLB transplantation with PAC vs. SAC, respectively (NS). SAC safely reduces severe ACS after paediatric SBMT and can be combined with graft reduction for transplantation of small recipients.

Use of an omega-3 fatty acid-based emulsion in the treatment of parenteral nutrition-induced cholestasis in patients with microvillous inclusion disease

Microvillous inclusion disease is a congenital intestinal epithelial cell disorder leading to lifelong intestinal failure. In this report, we discuss the use of a fish oil-based lipid emulsion in the treatment of 3 patients with microvillous inclusion disease who developed parenteral nutrition-associated liver disease.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.

NOD2 gene polymorphism rs2066844 associates with need for combined liver-intestine transplantation in children with short-gut syndrome

OBJECTIVES

The nucleotide-binding oligomerization protein 2 (NOD2) gene single nucleotide polymorphisms (SNPs) associated with Crohn's disease were recently associated with severe rejection after small-bowel transplantation (SBTx). The purpose of this study was to re-test this association and explore whether deficient innate immunity suggested by the NOD2 SNPs predisposes to intestine failure requiring isolated SBTx or combined liver-intestine failure requiring combined liver-SBTx (LSBTx).

METHODS

Archived DNA from 85 children with primary isolated SBTx or LSBTx was genotyped with Taqman biallelic discrimination assays. To minimize confounding effects of racial differences in minor allele frequencies (MAFs), allelic associations were tested in 60 Caucasian recipients (discovery cohort). Replication was sought in an independent cohort of 39 Caucasian pediatric and adult SBTx patients.

RESULTS

MAF for rs2066845 and rs2066847 was similar to that seen in 538 healthy North American Caucasians. In the discovery cohort, MAF for rs2066844 was significantly higher in LSBTx (13.5 vs. 3.6%, P=0.0007, Fisher's exact test), but not in isolated SBTx recipients (2.2 vs. 3.6%, P=NS), when compared with 538 healthy Caucasians. In addition, among LSBTx recipients who received identical immunosuppression, the minor allele of rs2066844 associated with early rejection in linear regression analysis (P=0.028) (all but one of the risk alleles were found in rejectors), decreased survival (P=0.015, log-rank, Kaplan-Meier analysis), and a 20-fold greater hazard of septic death in proportional hazard analysis (P=0.030). Steroid-resistant (severe) rejection and graft loss were associated with isolated SBTx (P=0.036 and 0.082, respectively), but not with NOD2 SNPs. The association between rs2066844 and combined liver-intestine failure requiring LSBTx was significant in the replication cohort (P=0.014), and achieved greater significance in the combined cohort (P=0.00006).

CONCLUSIONS

The NOD2 SNP rs2066844 associates with combined liver and intestinal failure in subjects with short-gut syndrome, who require combined liver-intestine transplantation, and secondarily with early rejection and septic deaths.

Intestinal transplantation in children: a review of immunotherapy regimens

This review summarizes the outcomes and known adverse effects of current immunosuppression strategies in use in pediatric intestinal transplantation. Intestinal transplantation has evolved from an experimental therapy to a highly successful treatment for children with intestinal failure who have complications with total parenteral nutrition. Because of continued success with intestinal transplantation over the past decade, the focus of clinicians and researchers is shifting from short-term patient survival to optimizing long-term outcomes. Current 5-year patient and graft survival rates after intestinal transplantation are 58% and 40%, respectively, in the US; single centers have reported nearly 80% patient and 60% graft survival rates at 5 years. The immunosuppression strategy in intestinal transplantation includes a tacrolimus-based regimen, usually in conjunction with an antibody induction therapy such as rabbit-antithymocyte globulin, interleukin-2 receptor antagonists, or alemtuzumab. The use of these immunosuppressive regimens, along with improved medical and surgical care, has contributed significantly toward improved outcomes. Optimization of post-transplant immunosuppression strategies to reduce adverse effects while minimizing acute and chronic graft rejection is a strong clinical and research focus.

Intestine transplantation in children: update 2010

This article reviews the current status of pediatric intestinal transplantation, focusing on referral and listing criteria, surgical techniques, patient management, monitoring, complications after transplant, and short- and long-term patient outcome. Intestine transplantation has become the standard of care for children who develop life-threatening complications associated with intestinal failure. The results of intestinal failure treatment have significantly improved in the last decade following the establishment of gut rehabilitation programs and advances in transplant immunosuppressive protocols, surgical techniques, and posttransplant monitoring. The 1-year patient survival is now 80% and more than 80% of the children who survive the transplant are weaned off parenteral nutrition. Early referral for pretransplant assessment and careful follow-up after transplant with prompt recognition and treatment of transplant-related complications are key factors contributing to superior patient outcomes and survival. The best results are being obtained at high-volume centers with survival rates of up to 75% at 5 years.

Psychiatric issues in pediatric organ transplantation

Solid organ transplantation has become the first line of treatment for a growing number of life-threatening pediatric illnesses. With improved survival, research into the long-term outcome of transplant recipients has become important to clinicians. Adherence to medical instructions remains a challenge, particularly in the adolescent population. New immunosuppressant approaches promise to expand organ transplantation in additional directions. Extension of transplantation into replacement of organs such as faces and hands raises complex ethical issues.