Pediatric intestinal and multivisceral transplantation: a new challenge for the pediatric intensivist

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.

Native Spleen Preservation During Visceral Transplantation Inhibits Graft-Versus-Host-Disease Development: Clinical and Experimental Study

OBJECTIVE

We aimed to assess whether native spleen preservation during visceral transplantation (VT) affects graft-versus-host-disease (GVHD) incidence.

SUMMARY BACKGROUND DATA

GVHD is one of the most severe and frequently lethal hematological complications after VT procedures. Because there is no specific treatment for GVHD, it is imperative to develop a strategy to reduce donor lymphocyte engraftment and proliferation.

METHODS

Our study included both clinical and experimental data. A total of 108 patients were divided into 3 groups: a native spleen preservation group, a native spleen removal with no donor spleen group, and a donor spleen included (allogeneic spleen) group. We also used an allogeneic VT rat model, in which recipients were divided into 2 groups: a native spleen preservation (+SP) group and a native spleen removal (-S) group. Skin rash appearance, histopathological changes, chimerism, and spleen effects on circulating allogeneic T-cells were assessed.

RESULTS

The patients with native spleen preservation showed a lower rate of GVHD ( P <.001) and better survival ( P <.05) than those in the other groups. Skin and histological signs of GVHD were lower in the rats in the +SP group ( P <.05). The donor T-cell frequency in the bloodstream and skin was also significantly reduced when the native spleen was preserved ( P <.01 and P <.0001, respectively).

CONCLUSIONS

The clinical and experimental data indicate that recipient spleen preservation protects against GVHD after VT, and donor cell clearance from the bloodstream by spleen macrophages could be the underlying mechanism. Therefore, spleen preservation should be considered in VT procedures, whenever possible.

Genetic predictors of gene expression associated with psychiatric comorbidity in patients with inflammatory bowel disease - A pilot study

BACKGROUND

Inflammatory bowel disease (IBD) affects millions of people in North America, and patients with IBD have a high incidence of psychiatric comorbidities (PC). The genetic mechanisms underlying the link are, in general, poorly understood.

MATERIALS AND METHODS

A transcriptome-wide association study (TWAS) was performed using genetically regulated gene expression profiles imputed from the genetic profiles of 240 IBD patients in the Manitoba IBD Cohort Study. The imputation was performed using the 44 non-diseased human tissue-specific reference models from the GTEx database. Linear modeling and gene set enrichment analysis were performed to identify genes and pathways that are significantly associated with IBD patients with PC compared to IBD alone in each of the 44 non-diseased human tissues. Finally, an enrichment map was generated to investigate networks of the enriched gene sets associated with IBD patients with PC.

RESULTS

The genes RBPMS in skeletal muscle (adjusted p = 0.05), KCNA5 in the cerebellar hemisphere of the brain (adjusted p = 0.09), GSR, SMIM34A, and LIPT2 in the frontal cortex of the brain (adjusted p = 0.09 for each) were the top genetically regulated genes with a suggestive association with IBD patients with PC. We identified three gene set networks, which include gene sets and pathways with a suggestive association with IBD patients with PC: one with 7 gene sets overlapping in apolipoprotein B mRNA editing subunit genes, one with 3 gene sets including pigmentation gene sets, and the other one with 3 gene sets including peptidyl tyrosine phosphorylation regulation related gene sets.

CONCLUSIONS

Our TWAS analysis has identified genes and pathways with a suggestive association with IBD patients with PC. These findings can be potentially used for illustrating the mechanism of developing PC in the patients with IBD and developing diagnosis tool or drug targets for IBD patients with PC.

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.

The use of vascular homografts in pediatric small bowel transplantation: Single-center experience over a decade

Intestinal transplantation in children has evolved with more isolated small intestine transplants being performed compared to combined liver-intestine transplants. Consequently, surgical techniques have changed, frequently requiring the use of vascular homografts of small caliber to revascularize the isolated small intestine, the impact of which on outcomes is unknown. Among 106 pediatric intestine and multivisceral transplants performed at our center since 2003, 33 recipients of an isolated small intestine graft were included in this study. Outcome parameters were thrombotic complications, graft, and patient survival. A total of 29 of 33 (87.9%) patients required arterial and/or venous homografts from the same donor, mainly iliac or carotid artery and iliac or innominate vein, respectively (donor's median age 1.1 years [2 months to 23 years], median weight 10 kg [14.7-48.5]). Post-transplant, there were three acute arterial homograft thromboses and one venous thrombosis resulting in two peri-operative graft salvages and two graft losses. Three of four thromboses occurred in patients with primary hypercoagulable state, including the two graft losses. Overall, at a median of 4.1 years (1-10.2) from transplant, 29 of 33 (88%) patients are alive with 26 of 33 (79%) functioning grafts. The procurement of intact, size-matched donor vessels and the management of effective post-transplant anticoagulation are critical.

Neurologic aspects of multiple organ transplantation

Complex multiorgan failure may require simultaneous transplantation of several organs, including heart-lung, kidney-pancreas, or multivisceral transplantation. Solid organ transplantation can also be combined with hematopoietic stem cell transplantation to modulate immunologic response to a solid organ allograft. Combined multiorgan transplantation may offer a lower rate of allograft rejection and lower immunosuppression needs. In recent years, intestinal and multivisceral transplantations became viable as a rescue treatment for patients with irreversible intestinal failure who can no longer tolerate total parenteral nutrition with 70% survival after 5 years which is comparable to other types of solid organ allografts. Post-transplant neurologic complications were reported in up to 86% of allograft recipients and greatly overlap in intestinal and multivisceral allograft recipients, without a significant effect on the outcome of transplantation. Other common organ combinations in multiorgan transplantation include kidney-pancreas, which is mostly used for patients with renal failure and uncontrolled diabetes, and heart-lung for patients with congenital heart disease and idiopathic pulmonary arterial hypertension. Kidney-pancreas transplantation frequently results in an improvement of diabetic complications, including diabetic neuropathy. Heart-lung allograft recipients have very similar clinical course and spectrum of neurologic complications to lung transplant recipients. At this time there are no reports of an increased risk of graft-versus-host disease with combined transplantation of solid organ allograft and hematopoietic stem cells. Chronic immunosuppression and complex toxic-metabolic disturbances after multiorgan transplantation create a permissive environment for development of a wide spectrum of neurologic complications which largely resemble complications after transplantations of individual components of complex multiorgan allografts.

Clinical practice guidelines--Nursing management for pediatric patients with small bowel or multivisceral transplant

PURPOSE

Small bowel or multivisceral transplant is a relatively new treatment for irreversible intestinal damage, and no published practice guidelines exist. The purpose of this article is to report evidence regarding the best plan of care to achieve adequate nutrition and appropriate development for children.

DESIGN AND METHODS

An integrative review was conducted with 54 articles related to management of this transplant population. A nine-member nursing team integrated the findings.

PRACTICE IMPLICATIONS

This resulting guideline represents the best research and best practices on which to base staff education and competency validations to manage this medically fragile patient population.

Factors affecting the duration of mechanical ventilation in patients after intestinal transplantation: preliminary results

OBJECTIVE

Intestinal transplantation (ITx) is a definitive therapy for patients with intestinal failure. However, postoperative respiratory care in such patients remains a clinical challenge. In this study, we investigated the factors affecting the duration of mechanical ventilation in patients who underwent ITx.

METHODS

In this observational study, eight patients who underwent ITx between 2007 and 2013 were studied. They were divided into two groups, with Group E including three patients who could be successfully extubated within 72 hours and Group V including the remaining five, who could not be extubated. The differences in demographical and clinical data between the two groups were evaluated.

RESULTS

The surgery success rate, patient survival rate, and graft survival rate were 100%, 88%, and 75%, respectively. Compared with Group E, postoperative bleeding was significantly higher in Group V (700 ± 420.7 mL vs. 50.0 ± 2.0 mL, p = 0.021). In addition, postoperative respiratory complications including pleural effusion and pneumonia (p = 0.017 and p = 0.0714, respectively) were prone to occur in Group V. Other variables including demographic parameters and clinical data showed no significant differences between the two groups. It was not unexpected that the duration of ventilator use and the length of intensive care unit stay were significantly shorter in Group E.

CONCLUSION

Postoperative blood loss and postoperative respiratory complications might be the factors responsible for delayed extubation in ITx patients. Because the study had few examinees, further studies with a larger population are needed to verify these issues.

Post-transplant critical care outcomes for pediatric multivisceral and intestinal transplant patients

This study reviews the post-operative management of pediatric intestinal transplant patients at a single center with reporting of standard PICU benchmarks for quality of care. It is a retrospective, descriptive, chart review describing our institution's experience between 2006 and 2010. Twenty patients were included. Median age at transplant was 1.6 yr. Median length of PICU stay was 12 days. Median ventilation time was two days. Median time for continuous sedation infusion was two days, with median continuous pain medication infusion of three days. All patients were placed on parental nutrition and started on enteral feedings between days 3 and 4. Forty percent of patients required hemodynamic support. Only 35% of patients required insulin therapy. Diuretics were frequently used in this patient population. There were no episodes of early rejection. The survival rate to PICU discharge was 95%. Our institution's experience over the past four yr has been very successful with a short duration of mechanical ventilation, limited use of pain and sedation drips, early initiation of enteral feedings, minimal hemodynamic support, and a low mortality rate to PICU discharge despite a preponderance of complex MVTx recipients.

Nonsurgical care of intestinal and multivisceral transplant recipients: a review for the intensivist

Intestinal and multivisceral transplantation has evolved from an experimental procedure to the treatment of choice for patients with irreversible intestinal failure and serious complications related to long-term parenteral nutrition. Increased numbers of transplant recipients and improved survival rates have led to an increased prevalence of this patient population in intensive care units. Management of intestinal and multivisceral transplant recipients is uniquely challenging because of complications arising from the high incidence of transplant rejection and its treatment. Long-term comorbidities, such as diabetes, hypertension, chronic kidney failure, and neurological sequelae, also develop in this patient population as survival improves. This article is intended for intensivists who provide care to critically ill recipients of intestinal and multivisceral transplants. As perioperative care of intestinal/multivisceral transplant recipients has been described elsewhere, this review focuses on common nonsurgical complications with which one should be familiar in order to provide optimal care. The article is both a review of the current literature on multivisceral and isolated intestinal transplantation as well as a reflection of our own experience at the University of Miami.

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.

Invasive Candida infections in solid organ transplant recipient children

Solid organ transplantation (SOT) is now an accepted therapy for many end-stage organ disorders and fungal infections are the principal cause of infection-related mortality in SOT recipients. Among invasive fungal infections, Candida species are the most common pathogens identified, associated with high mortality rates. The epidemiology and clinical manifestations of Candida infections vary with the type of organ transplantation. This article reviews invasive Candida infections in pediatric SOT recipients.

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.