Intestinal failure-associated liver disease: what do we know today?

Potential of cell therapy to treat pediatric motility disorders

Gut motility disorders represent a significant challenge in clinical management with current palliative approaches failing to overcome disease and treatment-related morbidity. The recent progress with stem cells to restore missing or defective elements of the gut neuromusculature offers new hope for potential cure. Focusing on enteric neuropathies such as Hirschsprung's disease, the review discusses the progress that has been made in the sourcing of putative stem cells and the studies into their biology and therapeutic potential. It also explores the practical challenges that must be overcome before stem cell-based therapies can be applied in the clinical arena. Although many obstacles remain, the speed of advancement of the enteric stem cell field suggests that such therapies are on the horizon.

Nutritional deficiencies in intestinal failure

Intestinal failure (IF) is the ultimate malabsorption state, with multiple causes, requiring long-term therapy with enteral or intravenous fluids and nutrient supplements. The primary goal during management of children with potentially reversible IF is to promote intestinal autonomy while supporting normal growth, nutrient status, and preventing complications from parenteral nutrition therapy. This article presents how an improved understanding of digestive pathophysiology is essential for diagnosis, successful management, and prevention of nutrient deficiencies in children with IF.

Isolated liver transplantation for treatment of liver failure secondary to intestinal failure

Intestinal Failure is a permanent loss of digestive and absorptive functions as a consequence of short bowel syndrome and/or other primary intestinal conditions. Patients with intestinal failure (IF) require long term parenteral nutrition to survive. The only alternative to parenteral nutrition is intestinal transplantation which still entails high mortality. Children with intestinal failure on parenteral nutrition may develop liver failure (LF), as a consequence of central line infections and other conditions. In children with both irreversible IF and LF a combined transplantation is generally considered. Despite low survival rate, combined liver/intestine transplantation is associated to better intestinal graft survival and lower incidence and severity of rejection compared to isolated small bowel transplantation. Recently, isolated liver transplantation was proposed in children with IF and LF. This procedure may have a higher survival probability compared to isolated intestinal transplant, it may allow progressive weaning from PN in children in whom the remnant intestine has the potential for adaptation and offer a timely solution in children for whom intestinal graft is not immediately available. This innovative approach may prove a better option compared to combined transplantation in both the short and long term.

Mitochondria-initiated apoptosis triggered by oxidative injury play a role in total parenteral nutrition-associated liver dysfunction in infant rabbit model

PURPOSE

The aim of the study was to investigate oxidative injury and apoptosis as the mechanisms underlying total parenteral nutrition (TPN)-associated liver dysfunction.

METHODS

Twenty New Zealand rabbits (2 weeks old) were divided into 2 groups as follows: 10 in the control group (maternal feed) and 10 in the TPN group. The rabbits in the TPN group received continuous PN infusion through a silastic catheter inserted in the right jugular vein.

RESULTS

After 10 days of treatment, the serum levels of total bilirubin and bile acid were significantly higher in the TPN group than in the control group (P < .01, respectively). The light microscopic findings in the TPN rabbits included inflammatory cell infiltration and hepatic steatosis. Electron microscopy showed change in the cytosolic vacuoles and rare microvilli in the microbile duct. Moreover, 10 days of treatment resulted in an inhibition of the superoxide dismutase (SOD) activity in hepatocytes, an increase of the malondialdehyde level, a significant increase in cytochrome c release from the mitochondria, a significant increase in caspase 3 activity, and increased apoptosis (P < .01, individually).

CONCLUSIONS

Oxidative damage may be one of the essential mechanisms of TPN-associated liver dysfunction. Moreover, mitochondria-initiated apoptosis triggered by oxidative damage may play an important role in this process.

Rapid reversal of parenteral-nutrition-associated cirrhosis following isolated intestinal transplantation

INTRODUCTION

Liver disease and the development of hepatic fibrosis are complications associated with total parenteral nutrition (TPN). Patients developing cirrhosis and portal hypertension in the setting of intestinal failure have a high mortality and may require combined liver and intestinal transplantation which carries much higher morbidity and mortality than isolated intestinal transplantation.

DISCUSSION

Recently, regression of hepatic fibrosis in patients with TPN liver disease has been described following intestinal transplantation. To date, there has been no demonstration of the reversal of established cirrhosis due to long-term TPN injury. Herein, we describe a patient with intestinal failure who developed cirrhosis from long-standing TPN injury and underwent isolated intestinal transplantation. He had no overt clinical stigmata of portal hypertension and had preserved liver function. Serial liver biopsies were reviewed and assessed with standard histology and quantitation of fibrosis using image analysis. Dramatic regression of fibrosis and reversal of cirrhosis were observed 17 months posttransplantation. Image analysis demonstrated a 14% total decrease in the percentage area of fibrosis.

CONCLUSIONS

Cirrhosis related to TPN may be rapidly reversible after isolated intestinal transplantation. Such patients may be able to undergo isolated intestinal transplantation if they do not have hepatic synthetic compromise or clinical stigmata of portal hypertension.

High rates of mortality and morbidity occur in infants with parenteral nutrition-associated cholestasis

BACKGROUND

Extremely few data are available about the natural history of parenteral nutrition (PN)-associated cholestasis. The authors evaluated a cohort of infants at a large center to determine the outcome of PN-associated cholestasis in infants with some gastrointestinal function.

METHODS

The authors reviewed the records of all infants admitted to a level 3 neonatal intensive care unit over a 16-month period who had the diagnosis of PN-associated cholestasis. Records were reviewed in these infants for course of cholestasis, laboratory values, outcome, and infection rate.

RESULTS

Sixty-six patients were admitted who met the study criteria. There were 10 deaths and 1 referral for liver transplant (Death/TPlant) (17%) in the first year of life. All Death/TPlant infants had at least 1 positive blood culture after the onset of cholestasis. Maximum conjugated bilirubin (MaxCB) in Death/TPlant infants was 15.7 +/- 2.2 (SEM) compared to 8.4 +/- 1.0 mg/dL in babies who recovered. Of 21 infants with a MaxCB > or =10.0, Death/TPlant occurred in 8/21 (38%). Of 40 babies with positive blood cultures, 11 were in the Death/TPlant group vs no deaths among the 25 without positive blood cultures. Average time to resolution from the MaxCB to a CB <2.0 mg/dL was 66 +/- 7 days (n = 49).

CONCLUSIONS

Infants with PN-associated cholestasis have high rates of mortality despite the presence of some gastrointestinal function. These data support further evaluation and the development of novel forms of therapy for babies with parenteral-associated CB > or =2 mg/dL with emphasis on interventions for infants with a CB >10 mg/dL.

ESPEN Guidelines on Parenteral Nutrition: home parenteral nutrition (HPN) in adult patients

Home parenteral nutrition (HPN) was introduced as a treatment modality in the early 1970s primarily for the treatment of chronic intestinal failure in patients with benign disease. The relatively low morbidity and mortality associated with HPN has encouraged its widespread use in western countries. Thus there is huge clinical experience, but there are still few controlled clinical studies of treatment effects and management of complications. The purpose of these guidelines is to highlight areas of good practice and promote the use of standardized treatment protocols between centers. The guidelines may serve as a framework for development of policies and procedures.

Long-term outcome of chronic intestinal pseudo-obstruction adult patients requiring home parenteral nutrition

OBJECTIVES

Chronic intestinal pseudo-obstruction (CIPO) is a rare, disabling disorder responsible for motility-related intestinal failure. Because it induces malnutrition, CIPO is a significant indication for home parenteral nutrition (HPN). The objective of the study was to evaluate long-term outcome of CIPO patients requiring HPN during adulthood.

METHODS

In total, 51 adult CIPO patients (18 men/33 women, median age at symptom occurrence 20 (0-74) years, 34/17 primary/secondary CIPO) followed up at our institution for HPN management between 1980 and 2006 were retrospectively studied for survival and HPN dependence rates using univariate and multivariate analysis.

RESULTS

Follow-up after diagnosis was 8.3 (0-29) years. Surgery was required in 84% of patients. The number of interventions was 3 +/- 3 per patient (mean +/- s.d.), leading to short bowel syndrome in 19 (37%) patients. Actuarial survival probability was 94, 78, 75, and 68% at 1, 5, 10, and 15 years, respectively. Multivariate analysis showed that lower mortality was associated with the ability to restore oral feeding at baseline (hazard ratio (HR) = 0.2 (0.06-0.65), P = 0.008) and symptom occurrence before the age of 20 years (HR=0.18 (0.04-0.88), P = 0.03). Higher mortality was associated with systemic sclerosis (HR=10.4 (1.6-67.9), P = 0.01). Actuarial HPN dependence was 94, 75, and 72% at 1, 2, and 5 years, respectively.

CONCLUSIONS

In this large cohort of CIPO adult patients with severe intestinal failure, i.e., those requiring HPN, we found a higher survival probability than previously reported. These results should be taken into account when considering intestinal transplantation.

Isolated liver transplant in infants with short bowel syndrome: insights into outcomes and prognostic factors

OBJECTIVE

Selected infants with short bowel syndrome (SBS) and progressive intestinal failure associated liver disease (IFALD) may benefit from isolated liver transplantation (iLTx). The aim of the study is to identify risk factors for unfavourable outcome in iLTx.

PATIENTS AND METHODS

A retrospective review of medical records from 1998 to 2005 was undertaken. Risk factors were assessed by comparing long-term survivors with those who died after iLTx.

RESULTS

Fifteen iLTx were performed in 14 infants with IFALD. All were parenteral nutrition (PN) dependent, but had tolerated enterally 54% (38-100) of energy intake before iLTx. Median residual bowel was 60 cm (30-200). Eight out of 14 had intact ileocaecal valve (ICV). Median bilirubin was 298 micromol/L (87-715) and all had portal hypertension. Eight out of 9 survivors were weaned from PN after median 15 months. In 4 out of 9 children, nontransplant surgery after iLTx facilitated intestinal adaptation. Growth velocity had improved at 3 years after iLTx (P=0.001). Five children who died had poor enteral tolerance following iLTx (P<0.002), which correlated with pretransplant dysmotility seen in 4 out of 5 children shown by contrast studies (P=0.02)and increased frequency of line infections before (>6/year P<0.04) and after (P<0.001) iLTx.

CONCLUSIONS

Isolated liver transplantation is a lifesaving option for selected children with SBS and IFALD. Revised criteria are proposed: progressive IFALD; 50 cm functional bowel in absence of ICV or 30 cm with ICV; 50% daily energy intake tolerated enterally for 4 weeks with satisfactory growth; and children with dysmotile bowel should be assessed for combined liver/bowel transplant unless the dysmotility is resolved and associated with minimal line infections.

Preservation of intestinal motility after the serial transverse enteroplasty procedure in a large animal model of short bowel syndrome

INTRODUCTION

Serial transverse enteroplasty (STEP) has been shown to improve bowel function in short bowel syndrome. The effect of the STEP procedure on intestinal motility is not known, but some have hypothesized that it could disrupt bowel innervation and thus impair intestinal motility.

METHODS

Growing Yorkshire pigs (n = 7) underwent 3 operations at 6-week intervals: (1) reversal of 50 cm of jejunum, (2) 90% bowel resection +/- STEP to the proximal dilated bowel (4 STEP, 3 control), and (3) implantation of serosal strain gauges. At each operation, baseline and post-octreotide small intestinal motility was studied with continuously perfused manometry catheters using non-anticholinergic anesthesia. In addition, awake monitoring was performed using strain gauge analysis 1 week after the third operation. Characteristics of phase III of the migrating motor complex (MMC) were compared between and within groups using t test, chi(2), and analysis of variance, with significance set at P < .05.

RESULTS

Manometry data from the third surgery revealed no differences between groups or compared with baseline within groups for the presence and characteristics of phase III of the MMC. Specifically, the mean amplitude and frequency of phase III after octreotide, and both the mean baseline and mean octreotide-stimulated motility indices were equivalent. The duration of phase III after octreotide stimulation was significantly increased in the STEP animals, suggesting a potential benefit of the STEP procedure. Strain gauge analysis, performed in awake animals, confirmed no differences between the groups for basal and octreotide-stimulated characteristics of phase III of the MMC.

CONCLUSIONS

These preliminary data suggest that the STEP procedure in a porcine model of short bowel syndrome does not interfere with baseline or hormonally stimulated motility within the small bowel. These findings further support the STEP procedure as a safe option for the surgical management of short bowel syndrome.

Neonatal onset intestinal failure: an Italian Multicenter Study

OBJECTIVE

To describe the natural course of intestinal failure with onset in the neonatal period to provide data regarding the occurrence and to provide a population-based survey regarding the spectrum of underlying diseases.

STUDY DESIGN

We performed a retrospective chart review including infants admitted to the neonatal intensive care unit of 7 Italian tertiary care centers. Intestinal failure was defined as a primary intestinal disease that induces the need of total parenteral nutrition (PN) for more than 4 weeks or the need of partial PN for more than 3 months.

RESULTS

The total number of live births during the study time within the enrolled institutions was 30 353, and the number of newborns admitted to the neonatal intensive care unit was 5088. Twenty-six patients satisfied the definition of intestinal failure; thus the occurrence rate of intestinal failure was 0.1% among live-birth newborns and 0.5% among infants at high risk. The main underlying diseases leading to intestinal failure in neonatal age were congenital intestinal defects (42.3%), necrotizing enterocolitis (30.8%), severe intestinal motility disorder (11.5%), intestinal obstruction (7.7%), structural enterocyte defects (3.8%), and meconium peritonitis (3.8%). After a follow-up of 36 months, 84.6% of patients achieved intestinal competence, 1 patient was still receiving home PN, 1 patient underwent transplantation, and 2 patients died. Cholestatic liver disease was diagnosed in 54% of observed children.

CONCLUSION

An understanding of the incidence, causes, and natural history of intestinal failure would be helpful to appropriately allocate resources and to plan clinical trials.

Could lipid infusion be a risk for parenteral nutrition-associated cholestasis in low birth weight neonates?

To assess whether lipid infusion could be a risk factor for parenteral nutrition-associated cholestasis (PNAC) in low birth weight neonates, 22 newborns with cholestasis (29.8 +/- 1.6 weeks, 1298 +/- 217 g) were compared with 22 without cholestasis (29.5 +/- 1.7 weeks, 1286 +/- 363 g). The mean level of peak direct bilirubin for the cholestasis group was 4.6 mg/dl compared to 1.2 mg/dl for the noncholestasis group. A univariate analysis revealed that PNAC was significantly related to duration of fasting (p = 0.008) and parenteral nutrition (p < 0.0001), days of antibiotics use (p = 0.025), positive C-reactive protein (p = 0.018) or gastric culture (p = 0.018), and feeding intolerance (p < 0.0001). Total amino acid amount (p < 0.0001), total lipid amount (p < 0.0001), and average daily lipid amount (p = 0.002) were significantly higher in the cholestasis group than in the noncholestasis group. Conversely, prenatal administration of dexamethasone was a significant protective factor of PNAC (p = 0.008). Logistic regression analysis revealed that the cumulative amount of lipid infusion was an independent risk factor for PNAC (p = 0.041; OR 1.174; CI 1.007-1.369). We suggest that decreasing the cumulative load of amino acids and intralipids with early trophic feeding, control of infection, and prenatal administration of dexamethasone could possibly attenuate the severity of PNAC.

Body composition and metabolic changes associated with massive intestinal resection in mice

BACKGROUND

The specific changes in body composition and metabolism during the adaptation response to massive intestinal loss are presently unclear. The present study was designed to determine alterations in these parameters using an established mouse model.

METHODS

Male C57/Bl6 mice underwent either 50% small bowel resection (SBR) or transection with reanastomosis (Sham) operation. Oxygen consumption per unit time, carbon dioxide production per unit time, respiratory quotient, and energy expenditure were measured by indirect calorimetry along with body composition determination by nuclear magnetic resonance at postoperative days 1, 3, 7, 14, 21, and 28.

RESULTS

The mice that underwent SBR had lower rates of metabolism as measured by decreased energy expenditure, carbon dioxide production per unit time and oxygen consumption per unit time when compared with the Sham group throughout the study period. During adaptation, SBR mice had restoration of body fat at two weeks after the operation while the lean mass and body weight remained lower throughout.

CONCLUSION

Without supplemental parenteral nutrition, the adaptation response to massive SBR is characterized by reduced energy metabolism and an inappropriate replenishment of fat stores over lean mass. Futures studies will be needed to determine the metabolic effects of various growth factors designed to enhance structural features of adaptation.

Future horizons in the treatment of enteric neuropathies

Enteric neuropathies comprise a vast and disparate array of congenital and acquired disorders of the enteric nervous system (ENS), reflecting both the complexity of its neuronal composition and the many interactions that modulate its function. Although present therapeutic strategies, largely limited to surgery and the provision of artificial nutrition, have transformed the early survival and life of sufferers, levels of morbidity and mortality remain unacceptably high. This highlights the need to develop new treatments for enteric neuropathies. In the last decade, the tremendous advances in molecular biology and genetics have significantly enhanced our understanding of ENS development and function. Coupled with equivalent progress in the fields of pharmacology and stem-cell biology, this has led to the identification of novel tools and targets for therapy, which either aim to optimise the function of the intrinsic ENS or replace/replenish components of an inadequate or dysfunctional ENS. This article reviews current work on a number of these interventions with a particular focus on the use of ENS stem cells as potential therapeutic tools for enteric neuropathies.

Lower insulin secretory response to glucose induced by artificial nutrition in children: prolonged and total parenteral nutrition

Long-term parenteral nutrition (TPN) in children is associated with sustained hyperinsulinemia due to a high nutriment infusion flow 12 h/24 h, with plausible lipotoxicity secondary to repeated lipid infusions and with changes in incretin hormone release. The aim of this study was to test whether long-term TPN can lead to an alteration in beta-cell function. Thirteen children (age 9.5 +/- 3.9 y) on total TPN without obvious alternation in glucose tolerance were included. beta-Cell function was quantified with an intravenous glucose tolerance test (IVGTT) and a graded glucose infusion. First phase insulin release (FPIR) was low in five patients. The same demonstrated a lower insulin release under graded glucose infusion, although plasma glucose reached values as high as 15 mM. These data emphasize that metabolic conditions induced by TPN can lead to lower insulin secretory response to glucose. Patients who remain dependent on TPN are at risk of developing glucose tolerance disorders.

Liver disease associated with intestinal failure in the small bowel syndrome

The introduction of the Total Parenteral Nutrition (TPN) has given rise to a new hope in the treatment of intestinal failure (LF) associated with the Short Bowel Syndrome (SBS). However, together with the TPN and the increase of survival of these patients, new problems and questions have emerged, as well as new therapeutical procedures. Taking into consideration this emerging reality, this paper has the purpose to undertake a review of current concepts and available treatments for patients with IF associated-liver disease. Although TPN provides an increase of survival of patients with intestinal failure, it is a potential source of complication such as: septicemia, hyperglycemia, venous thrombosis and liver disease. There are several hypothesis conceived to explain the liver disease associated to intestinal failure, however the only definite treatment as a potential to reverse the non-cirrhotic liver disease is the small intestine transplantation. Despite indications for intestine transplantation are not entirely defined in literature, the trend is its early indication in high-risk patients, preserving the liver integrity and preventing the eventual need of both liver and intestine transplantations altogether.

The significance of bowel permeability

PURPOSE OF REVIEW

In clinical research, increased permeability has been scrutinized as a potential indicator of the severity of gastrointestinal disease and as a potential cause of the perpetuation of severe inflammatory activity in infectious states. This review discusses old and recent epidemiological and clinical evidence to establish whether increased permeability in sepsis is a sequel or a cause of multiple organ failure. In addition, old and new evidence linking inflammation and permeability in abnormal gastrointestinal anatomy and function to liver abnormalities in susceptible patients will be reviewed.

RECENT FINDINGS

Intestinal permeability has been found to be increased in several gastrointestinal diseases but not to be a very good marker of the severity of disease. Evidence is put forward supporting the claim that increased intestinal permeability is part of generalized leakiness of tight junctions in multiple organ failure and to play a less strong role as a primary event in its pathogenesis. Endemic malnutrition has been shown to be caused by interplay between malnutrition and intestinal inflammation. Recently experimental evidence has been put forward suggesting that enteral fat has anti-inflammatory effects on the intestine via the autonomic nervous system. Old clinical and new epidemiological evidence links intestinal inflammation, disruption of the enterohepatic cycle of bile acids, and liver disease.

SUMMARY

The implications of the described findings are that inflammatory activity, locally induced by abnormal intestinal anatomy and disruption of the bile acid pool, or systemically by severe and uncontrolled inflammation/infection, should be the focus of treatment or research. In addition, the connection between intestinal inflammation and liver disease should be investigated.

Mechanisms of disease: update on the molecular etiology and fundamentals of parenteral nutrition associated cholestasis

Since its introduction into clinical practice, parenteral nutrition has revolutionized the care of premature neonates. Serum transaminase and bilirubin levels are commonly elevated in infants on parenteral nutrition, but their normalization is typical in the setting of short-term administration of parenteral nutrition uncomplicated by sepsis. Premature infants who require long-term parenteral nutrition are, however, at severe risk for developing life-threatening hepatic complications. These complications include cirrhosis, liver failure, and the concomitant risks of sepsis, coagulopathy and death. Premature infants and those with short-bowel syndrome are most susceptible to these morbid outcomes. Although it has been more than a quarter of a century since parenteral nutrition was first introduced and its association with hepatic complications described, the precise etiology of parenteral nutrition associated cholestasis (PNAC) remains a mystery; however, our understanding of the molecular components that contribute to PNAC has improved substantially. In this Review, we summarize the fundamentals of PNAC, describe animal models of the disease, review the hepatic bile acid transporters that are crucial for bile acid homeostasis, and define the roles that endotoxin, genetics, and the components of parenteral nutrition are likely to have in the molecular pathogenesis of this life-threatening condition.

La greffe intestinale

Even though surgical techniques for isolated intestine, liver-intestine, and multivisceral transplantations were developed in the 1960's, very few patients were transplanted before 1990 because initial immunosuppression regimens were insufficient, making intestine transplantation impossible. Intestine transplantation resulted in death in most patients within days or months. The discouraging results of the first clinical trials were due to technical complications, sepsis, and the failure of conventional immunosuppression to control rejection. By 1990 the development of tacrolimus-based immunosuppression and improved surgical techniques, the increased array of potent immunosuppressive medications, infection prophylaxis, and suitable patient selection helped improve actuarial graft and patient survival rates for all types of intestine transplantation. The aims of this review are to describe the current status of intestine transplantation including the underlying diseases and conditions that may be indications for intestine transplantation, to identify patient populations for this indication, to provide key steps for patient evaluation, to summarize current recommendations for immunosuppression, to list the most common postoperative complications, and to discuss the international experience of small bowel transplantation compiled and analyzed by the International Intestine Transplant Registry since 1985.

Identifying patients, on the first day of life, at high-risk of developing parenteral nutrition-associated liver disease

BACKGROUND

Prolonged use of parenteral nutrition (PN) in neonates can lead to parenteral nutrition-associated liver disease (PNALD), manifested by elevated direct bilirubin concentrations, and in some cases progressing to hepatic failure. When new potential means of preventing PNALD in the neonatal intensive care unit (NICU), such as Omegaven usage, are tested in clinical trials, the studies should enroll neonates at a very high risk of developing PNALD. However, it is not always clear, in the first days of life, which neonates are most likely to develop PNALD. Therefore, preparatory to devising studies of prophylaxis against PNALD, we conducted an evaluation of all NICU patients who received PN for >or=14 day, assessing their likelihood of developing PNALD.

METHODS

We performed an historic cohort analysis of all neonates in the Intermountain Healthcare system, receiving PN for 14 days or more during their stay, with dates of birth between 1 January, 2002 and 30 June, 2006.

RESULTS

During the 4(1/2)-year period, 9861 neonates were cared for in the Intermountain Healthcare NICUs. Of these, 9547 (96.8%) survived for at least 28 days, and of these 6543 (68.5%) received PN. Twenty-one percent (1366 patients) of those receiving PN, received it for >or=14 days. PNALD was ascertained in this group by a direct bilirubin >or=2.0 mg/dl. Neonates receiving PN for 14-28 days had a 14% incidence of PNALD, those receiving PN for 29-56 days had a 43% incidence, those receiving PN for 57-100 days had a 72% incidence and those receiving PN for >100 days had a 85% incidence. Groups of patients identifiable on the first day of life as having the highest risk of developing PNALD were birth weight <500 g (odds ratio (OR), 30.7), birth weight 500-749 g (OR, 13.1), gastrochisis (OR, 20.3) and jejunal atresia (OR, 24.0). Among 357 patients who developed PNALD, the highest direct bilirubin concentrations correlated with the highest serum alkaline phosphatase and transaminase concentrations. Deaths after 28 days were much more common in those with the highest direct bilirubin and transaminase concentrations (P<0.0001).

CONCLUSIONS

In the first days of life, certain NICU patients can be identified as being at very high risk for developing PNALD. These are patients <750 g birth weight, those with gastrochisis and those with jejunal atresia. We speculate that these groups would be reasonable subjects for including in a PNALD prophylaxis trial, testing new preventative strategies such as Omegaven usage.

Early central catheter infections may contribute to hepatic fibrosis in children receiving long-term parenteral nutrition

BACKGROUND

Bacterial infections in infants constitute a risk factor for parenteral nutrition (PN)-related cholestasis. The possible role of infections in the development of liver fibrosis, the most severe long-term complication, has yet to be documented. This study retrospectively compares the incidence of sepsis in children with and without severe liver fibrosis.

PATIENTS AND METHODS

Medical reports of 30 children in prolonged PN programs between March 1985 and March 2000 were reviewed. Starting at birth, the mean PN duration was 65 months (range, 8-150 months). According to the results of liver biopsy (LB), patients were split into 2 groups: group A (n = 16) with severe liver fibrosis (ie, septal fibrosis involving >50% of portal fields or cirrhosis) and group B (n = 14) with normal hepatic architecture or mild fibrosis (<50% of portal fields).

RESULTS

Duration of PN at the time of LB was shorter in group A (30.5 months; range, 8-96 months) than in group B (105 months; range, 37-150 months; P < 0.001). In group A the incidence of sepsis was significantly higher than in group B (3.2 +/- 0.3/year vs 1.5 +/- 0.2/year) and the first infection occurred earlier (group A, 1 month [range, 1-2 months]; group B, 4 months [range, 1-19 months]). By contrast, both groups were similar in terms of pregnancy duration, birth weight, age of PN onset, underlying diseases, mode of PN delivery, and number of cholestasis episodes.

CONCLUSIONS

Incidence and early onset of infections may contribute to the development of liver fibrosis in cases of long-term PN. New strategies are required in prevention and treatment of infections in children receiving PN.

Nutritional management of infants with short bowel syndrome

The prevalence of short bowel syndrome appears to be increasing because of more aggressive surgical and medical approaches to the management of neonatal intraabdominal catastrophies. Hence, a large cohort of neonates with intestinal failure occupies neonatal intensive care units, requiring chronic total parenteral nutrition (TPN) in hopes that the residual bowel will adapt, thereby permitting weaning of TPN. Alternatively, when there is no hope for adaptation, these infants are maintained on TPN in hopes that they will grow to a size and state of general health satisfactory for either isolated intestinal transplant when liver function is preserved or combined liver-intestinal transplantation when the liver is irreparably damaged. Thus, it is imperative to provide enough parenteral nutrition to facilitate growth while minimizing TPN constituents predisposing to liver damage. Liver disease associated with intestinal failure (IFALD) seems to occur due to a variety of host factors combined with deleterious components of TPN. Host factors include an immature bile secretory mechanism, bile stasis due to fasting, and repeated septic episodes resulting in endotoxemia. Many constituents of TPN are associated with liver damage. Excessive glucose may result in fatty liver and/or hepatic fibrosis, excessive protein may lead to reduced bile flow, and phytosterols present in intravenous lipid may produce direct oxidant damage to the liver or may impede cholesterol synthesis and subsequent bile acid synthesis. Parenteral strategies employed to minimize TPN damage include reducing glucose infusion rates, reducing parenteral protein load, and reducing parenteral lipid load. Furthermore, preliminary studies suggest that fish oil-based lipid solutions may have a salutary effect on IFALD. Ultimately, provision of enteral nutrition is imperative for preventing or reversing IFALD as well as facilitating bowel adaptation. While studies of trophic hormones are ongoing, the most reliable current method to facilitate adaptation is to provide enteral nutrition. Continuous enteral feeding remains the mainstay of enteral nutrition support.

Home parenteral and enteral nutrition

Home parenteral and enteral nutrition (HPEN) has evolved to become a very successful, lifesaving treatment in the management of patients with intestinal and oral failure, respectively. Nevertheless, the provision of HPEN remains intrusive, expensive, and continues to be associated with significant morbidity. The management of HPEN by a nutrition support team that optimally includes an experienced clinician, nurse specialist, dietitian, and pharmacist reduces HPEN-related morbidity and may reduce costs associated with its use. Because clinical expertise in the management of patients receiving HPEN is not widely available, the referral of these patients to experienced centers for periodic assessment should be encouraged.

Isolated liver and multivisceral transplantation for total parenteral nutrition-related end-stage liver disease

PURPOSE

Total parenteral nutrition (TPN) has prolonged survival in children with intestinal failure; however, end-stage liver disease owing to TPN-induced cholestasis (ESLD-TPN) may preclude its use. ESLD-TPN is an indication for isolated liver transplantation (ILT) or multivisceral transplantation (MVT). Isolated liver transplantation for ESLD-TPN should only be considered in patients who have the potential for enteral autonomy.

METHODS

We retrospectively reviewed the records of patients with ESLD-TPN who underwent ILT (n = 7) or MVT (n = 5) between 1994 and 2005. The median age at the time of transplantation was 10.0 months. Intestinal failure followed necrotizing enterocolitis (n = 3), gastroschisis (n = 3), gastroschisis with volvulus (n = 3), gastroschisis with atresia (n = 1), malrotation (n = 1), and megacystis microcolon intestinal hypoperistalsis syndrome (n = 1).

RESULTS

Isolated liver transplant patients had a median length of small bowel of 70 cm and tolerated a median of 50% of enteral calories. The median length of small bowel in patients who underwent MVT was 29 cm, and none tolerated more than 30% of goal enteral feeds. Reduced-size (n = 5) and whole-liver (n = 2) allografts were used for patients undergoing ILT. Patients undergoing MVT received liver-small bowel-pancreas (n = 4) or liver-small bowel-pancreas-colon (n = 1). Overall patient survival was 57% in ILT (median follow-up = 25.1 months); 3 survivors are TPN independent, and the fourth patient requires TPN 3 days/wk. Patient survival was 40% after MVT (median follow-up = 13.0 months); 1 MVT patient died of abuse 16.9 months after transplant and was TPN independent at the time of death. Both survivors are TPN independent. Bilirubin levels are within normal range in all survivors.

CONCLUSION

Isolated liver transplantation for ESLD-TPN in the setting of intestinal failure is a viable option in patients who have the potential for enteral autonomy. Multivisceral transplantation is the only alternative in patients without the potential for intestinal recovery. Survival can be achieved in patients with ESLD-TPN, but mortality remains high for both procedures.

Immuno-protective effect of liver on small bowel in combined transplantation of liver and small bowel

AIM: To develop a new combined transplan-tation model of liver and small bowel in rats, and to investigate the protective effect of trans-planted liver on transplanted small bowel.

METHODS: Closed colony Sprague Dawley rats and inbred Wistar rats were included in this study. Five groups were designed: isogene small bowel transplant group (A), isogene liver transplant group (B), xenogene small bowel transplant group (C), xenogene liver transplant group (D), combined transplant of liver and small bowel group (E). Only Wistar rats were used in group A and B, while SD and Wistar rats were used as donors and recipients respectively in group C, D and E. During the combined transplantation of liver and small bowel (CTLS) for the donors, inferior vena cava in chest was cut to construct a muff in the lateral wall of portal vein and cuff was placed. During the operation for the recipients, portal veins of the donors and recipients were connected using cuff technique, and re-arterialization was completed by anastomosing the superior mesenteric artery of graft with the right kidney artery of the recipients. Randomly selected 4 rats from each group were sacrificed on postoperative days (POD) 5, 7 and 14, and grafts were sampled. The rejection of graft was investigated through histopathological analysis, and the apoptosis of the cells of graft were evaluated by TUNEL.

RESULTS: The survival rate of CTLS was 73.3% (22/30). The pathological changes of ischemia and reperfusion injury were observed in group A and B, and the numbers of apoptotic cells in the grafts were decreased with the prolonging of time. However, acute rejection after transplantation appeared in group C and D, and there were more apoptotic cells in the grafts. Mild, moderate and severe acute rejection occurred on POD 5, 7 and 14, respectively in group C, while only mild or severe acute rejection appeared in group E. Furthermore, the number of apoptotic cells in the grafts of group E was markedly decreased on POD 14 in comparison with that of group C (16.9 ± 4.3 vs 20.5 ± 6.3, P < 0.05). The degrees of acute rejection after transplantation and cell apoptosis of the grafts were not significantly different between group D and E.

CONCLUSION: The technique used in this study is feasible for establishment of CTLS model, and the transplanted liver can protect the transplanted intestinal graft from rejection in CTLS.