Beyond 10 years, with or without an intestinal graft: Present and future?

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.

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.

Intestinal and Multivisceral Transplantation: Complications

Advancements in immunosuppression protocols, surgical techniques, and postoperative care in the last few decades have improved outcomes of intestinal transplant patients. Normal immediate postoperative imaging appearance can simulate pathology. Intestinal transplant recipients are prone for several postoperative complications due to the complex surgical technique, which involves multiple anastomoses, and immunogenic nature of the allograft intestine. Imaging plays a crucial role in detection of several major complications including infectious, immunologic, vascular, gastrointestinal, pancreaticobiliary, genitourinary, and neoplastic complications. The awareness of the posttransplant anatomy and normal imaging appearances helps radiologists anticipate and accurately detect posttransplant complications.

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.

Into the multi-omics era: Progress of T cells profiling in the context of solid organ transplantation

T cells are the common type of lymphocyte to mediate allograft rejection, remaining long-term allograft survival impeditive. However, the heterogeneity of T cells, in terms of differentiation and activation status, the effector function, and highly diverse T cell receptors (TCRs) have thus precluded us from tracking these T cells and thereby comprehending their fate in recipients due to the limitations of traditional detection approaches. Recently, with the widespread development of single-cell techniques, the identification and characterization of T cells have been performed at single-cell resolution, which has contributed to a deeper comprehension of T cell heterogeneity by relevant detections in a single cell - such as gene expression, DNA methylation, chromatin accessibility, surface proteins, and TCR. Although these approaches can provide valuable insights into an individual cell independently, a comprehensive understanding can be obtained when applied joint analysis. Multi-omics techniques have been implemented in characterizing T cells in health and disease, including transplantation. This review focuses on the thesis, challenges, and advances in these technologies and highlights their application to the study of alloreactive T cells to improve the understanding of T cell heterogeneity in solid organ transplantation.

Outcome of Total Colonic Aganglionosis Involving the Small Bowel Depends on Bowel Length, Liver Disease, and Enterocolitis

OBJECTIVES

Total colonic aganglionosis involving the small bowel is a rare form of Hirschsprung disease. We aim to analyse the long-term outcomes, digestive autonomy, and complications, to suggest recommendations for prevention and treatment.

METHODS

All patients born between 2000 and 2015 followed in our centre were retrospectively included. We analysed the length of aganglionosis, surgical procedures, growth, duration of parenteral nutrition (PN), enterocolitis, liver disease, intestinal transplantation.

RESULTS

Twenty-five patients were followed for a median of 10.9 years. Fifteen patients had less than 80 cm of ganglionic small bowel (SB) with a median of 20 cm. Ten patients had more than 80 cm of ganglionic sB with a median of 115 cm. The median PN duration was significantly shorter for patients with more than 80 cm: 0.9 versus 7.5 years in those with less than 80 cm (P  < 0.001). No patient with less than 80 cm was weaned off PN, except 1 who underwent intestinal transplantation. Ten patients with less than 80 cm develop enterocolitis on the excluded segment, leading to emergency entero-colectomy in 5. Liver disease was more frequent in patients with less than 80 cm (11 vs 0). Three patients required combined liver-intestine transplantation; 2 underwent an isolated intestinal transplantation.

CONCLUSIONS

Digestive autonomy was possible in most patients with more than 80 cm of ganglionic SB. The more severe complication was enterocolitis. Liver disease compromised long-term survival without transplantation. Both complications should be prevented by early diversion and enterectomy of the whole aganglionic segment. Follow-up in or together with a multidisciplinary intestinal rehabilitation centre is suggested.

Update on immunosuppressive strategies in intestinal transplantation

PURPOSE OF REVIEW

The intestine is the most immunologically complex solid organ allograft with the greatest risk of both rejection and graft-versus-host disease (GVHD). High levels of immunosuppression are required, further increasing morbidity. Due to low volume of transplants and few centers with experience, there is paucity of evidence-based, standardized, and effective therapeutic regimens. We herein review the most recent data about immunosuppression, focusing on novel and emerging therapies.

RECENT FINDINGS

Recent data are moving the field toward increasing use of basilixumab and consideration of alemtuzumab for induction and inclusion of mammalian target of rapamycin inhibitors and antimetabolites for maintenance. For rejection, we highlight novel roles for tumor necrosis factor-α inhibition, α4β7 integrin inhibition, microbiome modulation, desensitization protocols, and tolerance induction strategies. We also highlight emerging novel therapies for GVHD, especially the promising role of Janus kinase inhibition.

SUMMARY

New insights into immune pathways associated with rejection and GVHD in intestinal allografts have led to an evolution of therapies from broad-based immunosuppression to more targeted strategies that hold promise for reducing morbidity from infection, rejection, and GVHD. These should be the focus of further study to facilitate their widespread use.

Delayed introduction of sirolimus in paediatric intestinal transplant recipients: indications and long-term benefits

To review our experience using sirolimus in a single centre paediatric intestinal transplantation cohort. Intestinal transplant patients with more than 3 months follow-up were divided into two groups according to their immunosuppression regimen: tacrolimus, (TAC group, n = 45 grafts) or sirolimus (SRL group, n = 38 grafts), which included those partially or completely converted from tacrolimus to sirolimus. The indications to switch were tacrolimus side effects and immunological complications. Survival and complications were retrospectively analysed comparing both groups. SRL was introduced 9 months (0 months-16.9 years) after transplant. The main cause for conversion was worsening renal function (45%), followed by haemolytic anaemia (21%) and graft-versus-host-disease (16%). Both groups showed a similar overall patient/graft survival (P = 0.76/0.08) and occurrence of rejection (24%/17%, P = 0.36). Immunological complications did not recur after conversion. Renal function significantly improved in most SRL patients. After a median follow-up of 65.17 months, 28/46 survivors were on SRL, 26 with monotherapy, with good graft function. Over one-third of our patients eventually required SRL conversion that allowed to improve their kidney function and immunological events, without entailing additional complications or survival impairment. Further trials are warranted to clarify the potential improvement of the standard tacrolimus maintenance by sirolimus conversion or addition.

Abdominal Organ Transplantation: Noteworthy Literature in 2020

In 2020, we identified and screened over 490 peer-reviewed publications on pancreatic transplantation, over 500 on intestinal transplantation, and over 5000 on kidney transplantation. The liver transplantation section specially focused on clinical trials and systematic reviews published in 2020 and featured selected articles. This review highlights noteworthy literature pertinent to anesthesiologists and critical care physicians caring for patients undergoing abdominal organ transplantation. We explore a wide range of topics, including COVID-19 and organ transplantation, risk factors and outcomes, pain management, artificial intelligence, robotic donor surgery, and machine perfusion.

Long-term outcomes of intestinal transplantation

PURPOSE OF REVIEW

In this article, data from the intestinal transplant registry, recent publications and reviews in the field will be used to describe mortality, morbidity, complications, nutritional and psychosocial outcomes in intestinal transplant recipients with a focus on those furthest out from transplant.

RECENT FINDINGS

Registry data show static long-term survival data (41% 10-year survival in the most recent analysis), but experienced centres report improvements with survival between 60 and 70% at 10 years. Chronic rejection remains a problem for long-term graft survival, but understanding of humoral immunity is increasing. Nutritional outcomes are good with most recipients achieving enteral autonomy with an unrestricted diet. Health-related quality of life data generally shows improvement in the years after transplant, educational attainment is good, but some patients have ongoing psychosocial problems.

SUMMARY

Most patients do well in the long-term after transplant. Survival outcomes have improved in experienced centres, and nutrition and quality of life outcomes are good. Recognition of psychosocial outcomes is increasing. Nevertheless, challenges remain in areas such as infectious complications, renal function, chronic rejection, social support and mental health.