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

Role of probiotics in short bowel syndrome in infants and children--a systematic review

Short bowel syndrome (SBS) is a cause of significant morbidity and mortality in children. Probiotics, due to their beneficial effects on the gastrointestinal tract (e.g., improving gut barrier function, motility, facilitation of intestinal adaptation and decreasing pathogen load and inflammation) may have a therapeutic role in the management of SBS. To conduct a systematic review of the current evidence for the effects of probiotic supplementation in children with SBS, the standard Cochrane methodology for systematic reviews was used. The databases, Pubmed, Embase, ACTR, CENTRAL, and the international trial registry, and reference lists of articles were searched for randomised (RCT) or quasi-randomised controlled trials reporting on the use of probiotics in SBS. Our search revealed no RCTs on the use of probiotics in children with SBS. We found one small cross-over RCT (placebo controlled crossover clinical trial), one case control study and nine case reports on the use of probiotics in children with SBS. In the crossover RCT, there was no consistent effect on intestinal permeability (primary outcome) after supplementation with Lactobacillus rhamnosus (LGG) in nine children with SBS. The case control study (four cases: four controls) reported a trend for increase in height and weight velocity and improvement in non-clinical outcomes, such as gut flora, lymphocyte count and serum prealbumin. Five of the nine case reports showed that children (n = 12) with SBS were benefited (e.g., cessation of diarrhoea, improved faecal flora, weight gain and weaning from parenteral nutrition) by probiotic supplementation. The remaining four reported on the adverse effects, such as Lactobacillus sepsis (n = 3) and D-lactic acidosis (n = 2). There is insufficient evidence on the effects of probiotics in children with SBS. The safety and efficacy of probiotic supplementation in this high-risk cohort needs to be evaluated in large definitive trials.

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.

Pathogenesis and treatment of parenteral nutrition-associated liver disease

BACKGROUND

Parenteral nutrition-associated liver disease (PNALD) has been common in patients who require long-term parenteral nutrition. PNALD develops in 40%-60% of infants on long-term parenteral nutrition compared with 15%-40% of adults on home parenteral nutrition for intestinal failure. The pathogenesis of PNALD is multifactorial and remains unclear. There is no specific treatment. Management strategies for its prevention and treatment depend on an understanding of many risk factors. This review aims to provide an update on the pathogenesis and treatment of this disease.

DATA SOURCES

A literature search was performed on the MEDLINE and Web of Science databases for articles published up to October 2011, using the keywords: parenteral nutrition associated liver disease, intestinal failure associated liver disease, lipid emulsions and fish oil. The available data reported in the relevant literatures were analyzed.

RESULTS

The literature search provided a huge amount of evidence about the pathogenesis and management strategies on PNALD. Currently, lack of enteral feeding, extended duration of parenteral nutrition, recurrent sepsis, and nutrient deficiency or excess may play important roles in the pathogenesis of PNALD. Recent studies found that phytosterols, present as contaminants in soy-based lipid emulsions, are also an important factor in the pathogenesis. Moreover, the treatment of PNALD is discussed.

CONCLUSIONS

The use of lipid emulsions, phytosterols in particular, is associated with PNALD. Management strategies for the prevention and treatment of PNALD include consideration of early enteral feeding, the use of specialized lipid emulsions such as fish oil emulsions, and isolated small bowel or combined liver and small bowel transplantation. A greater understanding of the pathogenesis of PNALD has led to promising interventions to prevent and treat this condition. Future work should aim to better understand the mechanisms of PNALD and the long-term outcomes of its treatment.

Successful treatment of parenteral nutrition-associated liver disease in an adult by use of a fish oil-based lipid source

Liver disease occurs in 15% to 40% of adults on long-term parenteral nutrition, with steatosis being more common than cholestasis in the adult population. This problem has been well reported in the pediatric population, but we describe the case of a man who became profoundly jaundiced after being on parenteral nutrition for 3 y and responded rapidly to a change in lipid source from soybean and olive oil-based emulsion (ClinOleic) to a fish oil-based lipid emulsion (Omegaven).

Prevention and treatment of intestinal failure-associated liver disease in children

Intestinal failure-associated liver disease (IFALD), a serious complication occurring in infants, children, and adults exposed to long-term parenteral nutrition (PN), causes a wide-spectrum of disease, ranging from cholestasis and steatosis to fibrosis and eventually cirrhosis. Known host risk factors for IFALD include low birth weight, prematurity, short bowel syndrome, and recurrent sepsis. The literature suggests that components of PN may also play a part of the multifactorial pathophysiology. Because some intravenous lipid emulsions (ILEs) may contribute to inflammation and interfere with bile excretion, treatment with ILE minimization and/or ILEs composed primarily of omega-3 fatty acids can be helpful, but requires careful monitoring for growth failure and essential fatty acid deficiency (EFAD). Data from randomized controlled trials are awaited to support widespread use of these approaches. Other IFALD treatments include cycling PN, ursodeoxycholic acid, sepsis prevention, photoprotection, and polyvinylchloride-free tubing. Management and prevention of IFALD remains a clinical challenge.

Current pharmacotherapy for cholestatic liver disease

IMPORTANCE OF THE FIELD

The cholestatic liver diseases comprise a heterogeneous group of disorders which, left untreated, usually progresses to cirrhosis and liver failure. Most are recognized before the onset of advanced fibrosis, thereby affording an opportunity for disease modifying therapy.

AREAS COVERED

This review will cover the current pharmacologic management of the most common causes of cholestatic liver disease in adults, including primary biliary cirrhosis, primary biliary cirrhosis-autoimmune hepatitis overlap syndrome, primary sclerosing cholangitis, intrahepatic cholestasis of pregnancy, intestinal failure-associated liver disease, and immunoglobulin G4-associated cholangitis. Pharmacologic management of complications of cholestasis will also be reviewed.

EXPERT OPINION

Effective therapy for most cholestatic liver disease is lacking. Ursodeoxycholic acid (UDCA) slows the progression of primary biliary cirrhosis but the majority of patients do not have a full response. Even in those with a complete response, UDCA does not cure the disease. There is currently no effective medical therapy for primary sclerosing cholangitis. Symptoms and serum liver biochemistry values in intrahepatic cholestasis of pregnancy are improved with UDCA, but it is not certain if this alters the course of disease. Immunoglobulin G4-associated cholangitis is responsive to steroids but may relapse. The farnesoid X receptor agonists are a promising new class of drugs currently being tested in cholestatic liver disease.

Preresection obesity increases the risk of hepatobiliary complications in short bowel syndrome

Patients developing the short bowel syndrome (SBS) are at risk for hepatobiliary disease, as are morbidly obese individuals. We hypothesized that morbidly obese SBS individuals would be at increased risk for developing hepatobiliary complications. We reviewed 79 patients with SBS, 53 patients with initial body mass index (BMI) < 35 were controls. Twenty-six patients with initial BMI > 35 were the obese group. Obese patients were more likely to be weaned off parenteral nutrition (PN) (58% vs. 21%). Pre-resection BMI was significantly lower in controls (26 vs. 41). BMI at 1, 2, and 5 years was decreased in controls but persistently increased in obese patients. Obese patients were more likely to undergo cholecystectomy prior to SBS (42% vs. 32%) and after SBS (80% vs. 39%, p < 0.05). Fatty liver was more frequent in the obese group prior to SBS (23% vs. 0%, p < 0.05) but was similar to controls after SBS (23% vs. 15%). Fibrosis (8% vs. 13%) and cirrhosis/portal hypertension (19% vs. 21%) were similar in obese and control groups. Overall, end stage liver disease (ESLD) was similar in obese and control groups (19% vs. 11%) but was significantly higher in obese patients receiving PN (45% vs. 14%, p < 0.05). Obese patients developing SBS are at increased risk of developing hepatobiliary complications. ESLD was similar in the two groups overall but occurs more frequently in obese patients maintained on chronic PN.

Liver biopsy in modern clinical practice: a pediatric point-of-view

Liver biopsy remains the foundation of evaluation and management of liver disease in children, although the role of the liver biopsy is changing with development of alternative methods of diagnosis and advancement of hepatic imaging techniques. The indications for liver biopsy are evolving as current knowledge of etiologies, noninvasive biomarker alternatives, and treatment options in pediatric liver disease are expanding. The procedure can often be complicated in children by technical difficulties, cost, and smaller specimen size. Communication and partnership of clinicians with pathologists experienced in pediatric liver diseases are essential. DNA sequencing, novel imaging modalities, noninvasive biomarkers of fibrosis and apoptosis, proteomics, and genome-wide association studies offer potential alternative methods for evaluation of liver disease in children. This review presents specific indications, considerations, methods, complications, contraindications, and alternatives for pediatric liver biopsy.

Parenteral ω-3 fatty acid lipid emulsions for children with intestinal failure and other conditions: a systematic review

BACKGROUND

There is growing interest in the use of ω-3 fatty acid (n-3FA) lipid emulsions to prevent complications associated with parenteral nutrition. The authors systematically reviewed the evidence on the benefits and safety of n-3FA compared with standard lipid emulsions in children with intestinal disease, critical illness, trauma, or postoperative complications.

MATERIALS AND METHODS

The authors searched 4 bibliographic databases from their inception to March 2011, conference proceedings, trial registries, and reference lists. Two reviewers independently selected studies, assessed methodological quality, and rated the strength of the evidence. One reviewer extracted and a second reviewer verified data. The authors summarized findings qualitatively and conducted meta-analysis when appropriate.

RESULTS

Five randomized controlled trials with unclear risk of bias and 3 high-quality prospective cohort studies were included. The studies examined premature, low birth weight infants (n = 6) and children with heart disease (n = 1) or intestinal failure (n = 1). The strength of evidence was consistently low or very low across all lipid emulsion comparisons and outcomes. In young children, n-3FA emulsions resulted in improvement in some biochemical outcomes of intestinal failure-associated liver disease but no difference in mortality. Few studies examined patient-important outcomes, such as length of hospital and intensive care stay; need for transplantation, growth, and cognitive development; or the long-term effects and potential harms associated with these therapies.

CONCLUSIONS

Currently, there is a lack of sufficient high-quality data to support the use of parenteral n-3FA lipid emulsions in children. Future trials examining long-term clinical outcomes and harms are needed.

Parenteral plant sterols and intestinal failure-associated liver disease in neonates

OBJECTIVES

We prospectively evaluated incidence of prolonged (>28 days) parenteral nutrition (PN), associated complications, and significance of parenteral plant sterols (PS) in neonatal intestinal failure-associated liver disease (IFALD) compared with children.

METHODS

We recruited 28 neonates (mean age 50 days, range 28-126) and 11 children (6.9 y, 2.1-16.6) in all of Finland. Patients underwent repeated measurements of serum cholesterol, noncholesterol sterols, including PS, cholestanol and cholesterol precursors, and liver biochemistry during and 1 month after discontinuation of PN. Healthy matched neonates (n=10) and children (n=22) served as controls.

RESULTS

IFALD occurred more frequently among neonates (63%) than children (27%; P<0.05). Ratios of serum PS, including stigmasterol, sitosterol, avenasterol, and campesterol, and total PS were increased among neonates compared with healthy controls and children on PN by 2- to 22- and 2- to 5-fold (P<0.005), respectively. Neonates with IFALD had significantly higher ratios of serum PS and cholestanol compared with neonates without IFALD (P<0.05). Total duration of PN associated with serum cholestanol, stigmasterol, avenasterol, alanine aminotransferase, and aspartate aminotransferase (r=0.472-0.636, P<0.05). Cholestanol and individual serum PS, excluding campesterol, reflected direct bilirubin (r=0.529-0.688, P<0.05). IFALD persisted after discontinuation of PN in 25% of neonates with 4.2- and 2.2-times higher ratios of serum stigmasterol and cholestanol compared with neonates without IFALD (P<0.05).

CONCLUSIONS

Frequent occurrence of IFALD among neonates on PN displays an association to duration of PN and markedly increased serum PS, especially stigmasterol, in comparison to healthy neonates and children on PN. Striking accumulation of parenteral PS may contribute to IFALD among neonates.

[Pharmacological treatment for retinopathy of prematurity]

Mandatory screening performed by an experience ophthalmologist remains the most important pillar in the management of retinopathy of prematurity (ROP). The current gold standard for treatment of proliferative ROP is still panretinal laser photocoagulation, depending on severity, in combination with vitreoretinal surgery if necessary. The first case series of off-label intravitreal anti-VEGF treatment are encouraging. In addition to intravitreal anti-VEGF therapy, other treatment concepts such as supplementation with IGF-1 or omega-3 fatty acids also represent interesting pharmacological approaches to the management of ROP. However, larger controlled trials are required to validate the benefits and safety of these systemic treatment approaches.

Effect of alpha-naphthylisothiocyanate-induced liver injury on intestinal adaptation in a rat model of short bowel syndrome

BACKGROUND/PURPOSE

Progressive hyperbilirubinemia and end-stage liver failure are among the most serious complications of short bowel syndrome (SBS), representing the principle cause of death in a majority of fatal cases. In the current study, we examined the effects of alpha-naphthylisothiocyanate (ANIT)-induced liver injury on intestinal adaptation in a rat model of SBS.

METHODS

Male rats were divided into four groups: Sham rats underwent bowel transection (n = 8), Sham liver-injury rats underwent bowel transection and IP injection of ANIT (100 mg/kg, n = 8), SBS rats underwent a 75% bowel resection, and SBS-ANIT rats underwent bowel resection and liver injury similar to group sham-ANIT (n = 8). Fourteen days after intervention, liver biopsies and intestinal samples were obtained and evaluated for liver damage and measures of intestinal adaptation. Real time PCR and Western blotting were used to determine the level of bax and bcl-2 mRNA and protein, and p-ERK protein levels. Statistical analysis was performed using the one-way ANOVA test, with p < 0.05 considered statistically significant.

RESULTS

All ANIT-treated animals exhibited histological evidence of liver damage that was associated with the expansion of atypical ductal proliferation near the periportal areas, intense neutrophil infiltration in the liver, increased mitotic activity, Kupfer cells hyperplasia and fatty liver degeneration. ANIT-induced liver damage in bowel resected animals was associated with a significant decrease in all parameters of intestinal adaptation including bowel and mucosal weight in jejunum (twofold decrease) and ileum (twofold decrease), mucosal DNA in jejunum (fourfold decrease), mucosal protein in jejunum (threefold decrease) and ileum (threefold decrease), villus height in jejunum (38%) and ileum (34%), and crypt depth in jejunum (24%) and ileum (30%) compared to SBS animals. Both Sham-ANIT and SBS-ANIT rats demonstrated decreased enterocyte proliferation rates that were accompanied by decreased p-ERK protein levels. Lower apoptotic rates in jejunum (40%) and ileum (52%) in SBS-ANIT rats (vs. SBS) coincided with decreased bax mRNA and protein levels.

CONCLUSIONS

In a rat model of SBS, ANIT-induced liver injury was associated with decreased enterocyte proliferation and inhibited intestinal adaptation.

Parenteral nutrition-associated cholestasis: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee systematic review

OBJECTIVE

The aim of this study was to review evidence-based data addressing key clinical questions regarding parenteral nutrition-associated cholestasis (PNAC) and parenteral nutrition-associated liver disease (PNALD) in children.

DATA SOURCE

Data were obtained from PubMed, Medicine databases of the English literature (up to October 2010), and the Cochrane Database of Systematic Reviews.

STUDY SELECTION

The review of PNAC/PNALD has been divided into 4 areas to simplify one's understanding of the current knowledge regarding the pathogenesis and treatment of this disease: (1) nonnutrient risk factors associated with PNAC, (2) PNAC and lipid emulsions, (3) nutritional (nonlipid) considerations in the prevention of PNAC, and (4) supplemental medications in the prevention and treatment of PNAC.

RESULTS

The data for each topic area relevant to the clinical practice of pediatric surgery were reviewed, evaluated, graded, and summarized.

CONCLUSIONS

Although the conditions of PNAC and PNALD have been well recognized for more than 30 years, only a few concrete associations and treatment protocols have been established.

Enteral bile acid treatment improves parenteral nutrition-related liver disease and intestinal mucosal atrophy in neonatal pigs

Total parenteral nutrition (TPN) is essential for patients with impaired gut function but leads to parenteral nutrition-associated liver disease (PNALD). TPN disrupts the normal enterohepatic circulation of bile acids, and we hypothesized that it would decrease intestinal expression of the newly described metabolic hormone fibroblast growth factor-19 (FGF19) and also glucagon-like peptides-1 and -2 (GLP-1 and GLP-2). We tested the effects of restoring bile acids by treating a neonatal piglet PNALD model with chenodeoxycholic acid (CDCA). Neonatal pigs received enteral feeding (EN), TPN, or TPN + CDCA for 14 days, and responses were assessed by serum markers, histology, and levels of key regulatory peptides. Cholestasis and steatosis were demonstrated in the TPN group relative to EN controls by elevated levels of serum total and direct bilirubin and also bile acids and liver triglyceride (TG) content. CDCA treatment improved direct bilirubin levels by almost fourfold compared with the TPN group and also normalized serum bile acids and liver TG. FGF19, GLP-1, and GLP-2 were decreased in plasma of the TPN group compared with the EN group but were all induced by CDCA treatment. Intestinal mucosal growth marked by weight and villus/crypt ratio was significantly reduced in the TPN group compared with the EN group, and CDCA treatment increased both parameters. These results suggest that decreased circulating FGF19 during TPN may contribute to PNALD. Moreover, we show that enteral CDCA not only resolves PNALD but acts as a potent intestinal trophic agent and secretagogue for GLP-2.

Teduglutide for the treatment of short bowel syndrome

Extensive resection of the intestine impairs its absorptive capacity and results in short bowel syndrome when the nutritional equilibrium is compromised. The remnant intestine adapts structurally to compensate, but nutritional autonomy cannot be achieved in patients with intestinal failure, requiring intravenous fluids and parenteral nutrition (PN) for sustenance of life. PN is expensive and associated with serious complications. Efforts to minimize or eliminate the need for PN heralded research focusing on the therapeutic utility of intrinsic gut factors involved in the postresection adaptation process. With the breakthrough recognition of the intestinotrophic properties of glucagon-like peptide-2, teduglutide, a recombinant analogue of glucagon-like peptide-2, is being investigated as a promising hope to mitigate the requirement of PN. Clinical studies to date have demonstrated a desirable benefit-to-risk profile in regards to its safety and efficacy. If approved for marketing, it will be the first of its class in short bowel syndrome management, offering an innovative therapeutic modality for this debilitating condition.

Medical and surgical management of the pediatric patient with intestinal failure

Until recently, extreme short bowel due primarily to massive resection in the neonatal period had been considered incompatible with long-term survival. Indeed, parents of infants with midgut volvulus or other causes of very extensive intestinal necrosis still may be informed that resection is futile. The advent of intestinal transplantation as a potential therapy and its evolution into a standard therapy for irreversible intestinal failure have led to changing attitudes regarding these catastrophic gastrointestinal events. The experience gained from aggressively maintaining infants with little if any functional small bowel while awaiting transplantation has led to the increasing recognition that long-term survival is possible in many of these children with and often without intestinal transplantation. Even children with very small lengths of residual intestine ultimately may adapt and grow sufficiently to allow enteral autonomy. Achievement of these outcomes requires early referral to a dedicated multidisciplinary intestinal care team well versed in the management options for such children. Initial assessment often involves an inpatient evaluation followed by very close outpatient follow-up. Aggressive management is imperative for all patients with intestinal failure, allowing time for full enteral adaptation before complications become life-threatening; those with no possibility of significant adaptation can achieve optimal growth while awaiting transplantation. Along with medical and nutritional therapy and nontransplant surgery, intestinal transplantation should be seen as one of many modalities available for the optimal management of this population of patients. Thus, patients with irreversible intestinal failure and those with indications for transplantation (even those for whom hope remains that sufficient enteral adaptation still may occur) should be evaluated by the transplant team. If there is no intestinal transplant program at the center undertaking the intestinal failure management, strong links and regular communication with an intestinal transplant program that can partner in the care of these patients should be established. Multicenter collaborative and interventional studies are necessary to clearly demonstrate outcomes and to move the field forward.

Effect of omega-3 polyunsaturated fatty acids to reverse biopsy-proven parenteral nutrition-associated liver disease in adults

BACKGROUND & AIMS

Parenteral nutrition-associated liver disease (PNALD) complicates the treatment of patients with short bowel syndrome (SBS). Some studies have shown omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have favorable effects in treating PNALD in children. We, therefore, investigate the effects of ω-3 PUFAs supplemented intravenous lipid emulsion (ILE) on PNALD in adults.

METHODS

We performed an open-labeled study of a ω-3 PUFAs based ILE in 15 adults with SBS who developed cholestasis while receiving soybean oil-based ILE. Liver biopsies were performed before and after the initiation of ω-3 PUFAs to confirm the presence and improvement of cholestasis. Blood samples were collected every week for analysis of fatty acid composition and liver function.

RESULTS

12 of the 15 patients had their direct bilirubin normalized within 4 weeks and our data demonstrated a significant decrease in both DB (P ≤ 0.001) and TB (P ≤ 0.001) after 4 weeks compared to baseline. There were ameliorations of liver function and fatty acid patterns in all patients and serial liver biopsy specimens showed progressive histologic improvement.

CONCLUSIONS

Parenteral ω-3 PUFAs supplemented fat emulsions are safe and effective in the treatment of PNALD in adults.

Cycled enteral antibiotics reduce sepsis rates in paediatric patients on long-term parenteral nutrition for intestinal failure

BACKGROUND

Long-term parenteral nutrition has transformed the prognosis for children suffering from intestinal failure. However, parenteral nutrition itself is associated with considerable morbidity and mortality including that caused by sepsis.

AIM

To examine a strategy of cycled enteral antibiotics in reducing the incidence of sepsis in paediatric intestinal failure patients.

METHODS

Retrospective analysis of the incidence of sepsis rates of patients on long-term parenteral nutrition, at a tertiary paediatric hospital. Patients were separated into those who received cycled enteral antibiotics and a control group. Sepsis rates before and during cycled enteral antibiotics were compared with comparable timeframes between the cycled enteral antibiotics and control groups. Central venous catheter removal rates were also compared.

RESULTS

Fifteen patients (eight cycled enteral antibiotics, & seven controls) received 9512 parenteral nutrition days, with a total of 132 sepsis episodes. All eight patients of the treatment group demonstrated a decrease in the frequency of episodes of sepsis following the introduction of cycled enteral antibiotics. The cycled enteral antibiotics group had a significant reduction in infection rate during the treatment period (from 2.14 to 1.06 per 100 parenteral nutrition days, P = 0.014: median effect size -1.04 CI 95%-1.93, -0.22), whereas the controls had no significant change (1.91 - 2.36 per 100 parenteral nutrition days P = 0.402: median effect size 0.92 CI 95%-1.96, 4.17). The central venous catheter survival rates increased in the cycled enteral antibiotics group from 0.44 central venous catheter removals per 100 parenteral nutrition days to 0.27 central venous catheter removals per 100 parenteral nutrition days, although this was not statistically significant.

CONCLUSIONS

Cycled enteral antibiotics significantly reduced the rate of sepsis in a small group of paediatric intestinal failure patients. Larger well-designed prospective studies are warranted to further explore this finding.

The impact of MELD/PELD revisions on the mortality of liver-intestine transplantation candidates

Patients listed for liver-intestine transplantation suffer higher waiting list mortality than those listed for liver-only, thus leading to policy revisions seeking to close the gap. We sought to determine the impact of key model for end-stage liver disease (MELD)/pediatric end-stage liver disease (PELD) policy modifications on the waiting list mortality of adult and pediatric liver-intestine candidates as compared to liver-only candidates. Analysis of UNOS data separated into adult and pediatric categories and based on time periods of policy implementation revealed higher mortality in liver-intestine candidates over all time periods studied (p < 0.001 pediatric and adult). After implementation of a revision to augment their MELD scores based on a sliding scale, adult liver-intestine candidates with calculated MELD > 15 no longer suffered higher mortality although this change did not completely eliminate the mortality disparity for candidates with MELD < 15 (p < 0.01). The waiting list mortality of pediatric liver-intestine candidates dropped significantly after a revision that gave them 23 additional MELD/PELD points (p < 0.01) although the mortality disparity with pediatric liver-only candidates was not eliminated. Following this revision, mortality in pediatric liver-only and liver-intestine Status 1 candidates was similar, however more liver-intestine candidates were listed as Status 1B. This data demonstrates that a mortality disparity remains for liver-intestine candidates compared with candidates listed for liver-only.

A preliminary report on the significance of excessively long segment congenital hypoganglionosis management during early infancy

BACKGROUND/PURPOSE

Excessively long segment of congenital hypoganglionosis is rare, and therapeutic strategies to treat this disorder are not well established. The purpose of this study is to describe the significance of management in the neonatal and early infancy period.

PATIENTS AND METHODS

Four patients (aged 1-4 years) with hypoganglionosis were selected for this study, of which 3 were treated at our hospital. In the initial treatment of 3 cases, an intraoperative pathological diagnosis was made on the basis of findings from simultaneous biopsies taken from the jejunum and sigmoid colon. Retrospective reviews of these patients were performed.

RESULTS

Initial double-barrel jejunostomy at less than 50 cm from the ligament of Treitz allowed patients to start oral nutrition within a week following surgery. Subsequent refashioning of the initial jejunostomy to the Bishop-Koop type was performed at 3 to 6 months of age. Intravenous hyperalimentation was required to meet less than 50% of nutritional requirements, and patients were able to maintain their body weight within 1.5 SD of the normal mean body weight. Liver function test results were also within normal limits in the 3 patients treated at our hospital.

CONCLUSION

Early diagnosis and treatment may help improve the management of patients in the early stages of hypoganglionosis.

Are liver function tests, pancreatitis and cholecystitis predictors of common bile duct stones? Results of a prospective, population-based, cohort study of 1171 patients undergoing cholecystectomy

OBJECTIVE

The purpose of this study was to explore the accuracy of elevated liver function values, age, gender, pancreatitis and cholecystitis as predictors of common bile duct stones (CBDS).

METHODS

All patients operated on for gallstone disease over a period of 3 years in a Swedish county of 302,564 citizens were registered prospectively. Intraoperative cholangiography (IOC) was used to detect CBDS.

RESULTS

A total of 1171 patients were registered; 95% of these patients underwent IOC. Common bile duct stones were found in 42% of patients with elevated liver function values, 20% of patients with a history of pancreatitis and 9% of patients with cholecystitis. The presence of CBDS was significantly predicted by elevated liver function values, but not by age, gender, history of acute pancreatitis or cholecystitis. A total of 93% of patients with normal liver function tests had a normal IOC. The best agreement between elevated liver function values and CBDS was seen in patients undergoing elective surgery without a history of acute pancreatitis or cholecystitis.

CONCLUSIONS

Although alkaline phosphatase (ALP) and bilirubin levels represented the most reliable predictors of CBDS, false positive and false negative values were common, especially in patients with a history of cholecystitis or pancreatitis, which indicates that other mechanisms were responsible for elevated liver function values in these patients.

Intestinal involvement during 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced chronic liver injury in a mouse model

PURPOSE

Although a physiologic relationship between intestinal mucosal integrity and hepatic function has been previously described, the effect of primary liver disease on intestinal mucosal homeostasis has not been previously well documented. In the current study, we studied the effects of chronic liver injury as a primary injury on enterocyte turnover (proliferation and apoptosis) in a mouse model.

METHODS

The liver toxin 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-enriched diet was used to induce chronic cholestatic liver injury in mice. Livers and intestine were harvested after 3 weeks of dietary treatment of histologic analysis and a determination of cell proliferation (immunohistochemistry for Ki67), or apoptosis (immunohistochemistry for caspase-3), as well as a determination of Wnt/β-catenin signaling activity.

RESULTS

All DDC-fed animals exhibited histologic evidence of liver damage that was associated with the expansion of atypical ductal proliferation near the periportal areas and increased oxidative stress. In the intestine, DDC-induced liver damage was associated with decreased villus height, decreased enterocyte proliferation, and increased cell apoptosis compared with control animals. There was also evidence for decreased β-catenin expression by immunostaining in crypt and villus cells of DDC-fed mice compared with control animals.

CONCLUSION

Primary liver injury and cholestasis is associated with intestinal mucosal hypoplasia. Decreased cell proliferation and increased cell apoptosis may be responsible for decreased intestinal epithelial cell mass. The observed decrease in cell turnover is accompanied by an alteration in Wnt/β-catenin signaling.

High prevalence of multiple micronutrient deficiencies in children with intestinal failure: a longitudinal study

OBJECTIVE

To determine the prevalence of micronutrient deficiencies in children with intestinal failure as they transitioned from parenteral nutrition (PN) to enteral nutrition (EN).

STUDY DESIGN

We reviewed medical records of all patients with severe intestinal failure treated from 1999 to 2008 at a multidisciplinary intestinal rehabilitation program who had undergone micronutrient biochemical monitoring.

RESULTS

The cohort of 30 children (mean age, 5 years; range, 2 to 9 years; 18 boys) had median PN duration of 23 weeks (IQR, 13 to 34 weeks). Median transition from PN to full EN lasted 12 weeks (IQR, 8 to 20 weeks); during this transition, 33% of patients had at least one vitamin deficiency and 77% at least one mineral deficiency. After transition to 100% EN, 70% had at least one vitamin deficiency and 77% had at least one mineral deficiency, with the most common deficiencies being vitamin D (68%), zinc (67%), and iron deficiency (37%). After transition to 100% EN, multivariate analysis identified regular use of a multivitamin supplement (P=.004) and intact ileocecal valve (P=.02) as protective against the development of vitamin deficiencies, independent of bowel length, gestational age, and days on PN.

CONCLUSIONS

Children with intestinal failure exhibit a high prevalence of micronutrient deficiencies during intestinal rehabilitation. Regular monitoring and aggressive supplementation in children with intestinal failure is warranted.

Risk factors for parenteral nutrition–associated liver disease following surgical therapy for necrotizing enterocolitis: A Glaser Pediatric Research Network Study [corrected]

OBJECTIVE

The aim of the study was to prospectively determine risk factors for the development of parenteral nutrition-associated liver disease (PNALD) in infants who underwent surgery for necrotizing enterocolitis (NEC), the most common cause of intestinal failure in children.

PATIENTS AND METHODS

: From February 2004 to February 2007, we diagnosed 464 infants with NEC, of whom 180 had surgery. One hundred twenty-seven patients were available for full analysis. PNALD was defined as serum direct bilirubin ≥ 2 mg/dL or ALT ≥ 2 × the upper limit of normal in the absence of sepsis after ≥ 14 days of exposure to PN.

RESULTS

Median gestational age was 26 weeks and 68% were boys. Seventy percent of the cohort developed PNALD and the incidence of PNALD varied significantly across the 6 study sites, ranging from 56% to 85% (P = 0.05). Multivariable logistic regression analysis identified small-bowel resection or creation of jejunostomy (odds ratio [OR] 4.96, 95% confidence interval [CI] 1.97-12.51, P = 0.0007) and duration of PN in weeks (OR 2.37, 95% CI 1.56-3.60, P < 0.0001) as independent risk factors for PNALD. Preoperative exposure to PN was also associated with the development of PNALD; the risk of PNALD was 2.6 (95% CI 1.5-4.7; P = 0.001) times greater in patients with ≥ 4 weeks of preoperative PN compared with those with less preoperative PN use. Breast milk feedings, episodes of infection, and gestational age were not related to the development of PNALD.

CONCLUSIONS

The incidence of PNALD is high in infants with NEC undergoing surgical treatment. Risk factors for PNALD are related to signs of NEC severity, including the need for small-bowel resection or proximal jejunostomy, as well as longer exposure to PN. Identification of these and other risk factors can help in the design of clinical trials for the prevention and treatment of PNALD and for clinical assessment of patients with NEC and prolonged PN dependence.

Systematic review: medical and nutritional interventions for the management of intestinal failure and its resultant complications in children

BACKGROUND

Intestinal failure (IF) affects a growing number of children due to increasing numbers of preterm infants surviving intestinal resection for necrotising enterocolitis and improving surgical techniques for congenital gut anomalies. Parenteral nutrition (PN) is the mainstay of therapy; enteral nutrition may have trophic effects on the gut.

AIM

To review systematically evidence for the effectiveness of medical and nutritional interventions in the treatment of IF in children.

METHODS

Retrieval of data from studies of patients aged <18 years and receiving >28 days of PN. Outcome measures were improvement in intestinal function, intestinal adaptation, growth, prevention and treatment of IF-associated liver disease, and mortality. Cochrane Database (November 2009), MEDLINE (1950-November 2009) and CINAHL (1982-November 2009) electronic database searches were made using keyword and subject headings (MeSH): IF, Short Bowel Syndrome (SBS), PN and Child. The level of the evidence (EL) was assessed using SIGN (Scottish Intercollegiate Guidelines Network) methodology (http://www.sign.ac.uk).

RESULTS

From 1 607 620 hits, 720 abstracts were reviewed. Thirty-three original articles were included. No studies were of high methodological quality.

CONCLUSIONS

The evidence base for medical and nutritional interventions in paediatric IF is limited and of poor quality. In the absence of randomised-controlled trials, this evidence base can improve through case control and cohort research; and with better multiagency communication, the study of inter-centre differences is possible. Achievable short-term goals would include the study of: optimal ursodeoxycholic usage, novel intralipid formulations, cycled enteral antibiotics, enteral probiotics and new enteral feeding strategies.

Nutritional modulation of the gut microbiota and immune system in preterm neonates susceptible to necrotizing enterocolitis

The gastrointestinal inflammatory disorder, necrotizing enterocolitis (NEC), is among the most serious diseases for preterm neonates. Nutritional, microbiological and immunological dysfunctions all play a role in disease progression but the relationship among these determinants is not understood. The preterm gut is very sensitive to enteral feeding which may either promote gut adaptation and health, or induce gut dysfunction, bacterial overgrowth and inflammation. Uncontrolled inflammatory reactions may be initiated by maldigestion and impaired mucosal protection, leading to bacterial overgrowth and excessive nutrient fermentation. Tumor necrosis factor alpha, toll-like receptors and heat-shock proteins are identified among the immunological components of the early mucosal dysfunction. It remains difficult, however, to distinguish the early initiators of NEC from the later consequences of the disease pathology. To elucidate the mechanisms and identify clinical interventions, animal models showing spontaneous NEC development after preterm birth coupled with different forms of feeding may help. In this review, we summarize the literature and some recent results from studies on preterm pigs on the nutritional, microbial and immunological interactions during the early feeding-induced mucosal dysfunction and later NEC development. We show that introduction of suboptimal enteral formula diets, coupled with parenteral nutrition, predispose to disease, while advancing amounts of mother's milk from birth (particularly colostrum) protects against disease. Hence, the transition from parenteral to enteral nutrition shortly after birth plays a pivotal role to secure gut growth, digestive maturation and an appropriate response to bacterial colonization in the sensitive gut of preterm neonates.

[13C]Methionine breath test to assess intestinal failure-associated liver disease

Oxidation of L[1-C]methionine ([C]-Met) in liver mitochondria can be quantified by measuring exhaled CO2. We hypothesized that CO2 recovery after i.v. administered [C]-Met would provide a noninvasive measure of liver function in pediatric intestinal failure-associated liver disease (IFALD). After Institutional Review Board (IRB) approval, 27 patients underwent L[1-C]-Met breath tests ([C]-MBTs), five of whom underwent repeat testing after clinical changes in liver function. Sterile, pyrogen-free [C]-Met was given i.v. Six breath samples collected during 120 min were analyzed for CO2 enrichment using isotope ratio mass spectrometry. Pediatric end-stage liver disease (PELD) scores were recorded, and total carbon dioxide (CO2) production was measured by indirect calorimetry. Twenty-seven patients (median age = 5.3 mo) underwent a total of 34 [C]-MBTs without adverse events. Fourteen patients had documented liver biopsies (five with cirrhosis and nine with cholestasis or fibrosis). The [C]-MBT differentiated patients with and without cirrhosis (medians 210 and 350, respectively, p = 0.04). Serial [C]-MBTs in five patients reflected changing PELD scores. i.v. administering the stable isotope [C]-Met with serial breath sampling provides a useful, safe, and potentially clinically relevant evaluation of hepatic function in pediatric IFALD. The [C]-MBT may also help quantify progression or improvement of IFALD.

Use of the aspartate aminotransferase to platelet ratio index to follow liver fibrosis progression in infants with short gut

BACKGROUND

Infants with parenteral nutrition dependence may develop liver dysfunction and progress to liver failure requiring transplantation. The aspartate aminotransferase-to-platelet ratio index (APRI) has good correlation with liver fibrosis progression in adults. This study applies APRI scoring to parenteral nutrition-dependant, short-gut infants to determine hepatic fibrosis progression.

METHODS

Laboratory values and biopsies were collected from initial intestinal resection (time 0) up to transplantation (end). Fibrosis scoring ranged from F0 (normal) to F4 (cirrhosis). Children were divided into 3 groups: (1) isolated intestine; and combined liver/intestine with gestational age (2) 34 weeks or greater and (3) 30 weeks or less. Liver function values over time, including calculated APRI, were analyzed as predictors of fibrosis.

RESULTS

Fifteen children who had 33 biopsies were included. Median APRI by fibrosis grade was F < or = 2: 1.88, F3: 3.23, and F4: 14.16 (P < .01). Median APRI at transplant by study group was (1) isolated intestine: 2.47, (2) liver/intestine 35 weeks or longer EGA: 14.16, and (3) liver/intestine 30 weeks or less EGA: 14.74 (P = .04).

CONCLUSION

Progression of APRI up to 60 days initially demonstrates similar values among study groups, but over time the score distinguishes those children with impending liver cirrhosis and differentiates fibrosis grade and study group.

The Influence of Neocate in Paediatric Short Bowel Syndrome on PN Weaning

Clinical management of short bowel syndrome remains a multistage process. Although PN is crucial, early introduction of enteral feeding is mandatory. We describe retrospectively 4 patients with an ultrashort bowel who could be weaned off PN on very short terms after introduction of an amino-acid-based formula (Neocate). Patient 1 had congenital short bowel with 50 cm small bowel and 30 cm colon. He had persistent diarrhoea on a semielementary formula. When Neocate was introduced he could be weaned from PN within 6 months. Patient 2 needed multiple surgical interventions because of NEC at D 27. He maintained 40 cm small bowel and an intact colon and remained PN dependent on semielemental formula. After introducing Neocate, PN could be weaned within 3 months. In the next 2 patients, Neocate was introduced as initial enteral feeding after bowel resection following antenatal midgut volvulus. Patient 3 had 20 cm small bowel and an intact colon. PN was weaned after 2 months. Patient 4 had 9 cm small bowel and an intact colon. PN was weaned after 13 months. In all patients Ileocaecal valve (ICV) was preserved. No consensus is reached on the type of formula to use for short bowel syndrome. Compared to recent data in the literature, the weaning period in these 4 patients was significantly shortened on an aminoacid based formula. The reason for this may lie in the antiallergic properties of this formula. We recommend the use of an amino-acid-based formula to induce earlier weaning of PN.

Elimination of soybean lipid emulsion in parenteral nutrition and supplementation with enteral fish oil improve cholestasis in infants with short bowel syndrome

BACKGROUND

Parenteral nutrition-associated liver disease (PNALD) is a potentially fatal complication for children with intestinal failure. Fish oil-based lipid emulsions have shown promise for the treatment of PNALD but are not readily available. Six cases are presented in which cholestasis resolved after soybean lipid emulsion (SLE) was removed from parenteral nutrition (PN) and enteral fish oil was given.

METHODS

A retrospective review at a tertiary children's hospital (July 2003 to August 2008) identified 6 infants with intestinal failure requiring PN for >6 months who developed severe hepatic dysfunction that was managed by eliminating SLE and providing enteral fish oil.

RESULTS

Twenty-three infants with short bowel syndrome requiring prolonged PN developed cholestasis. SLE was removed in 6 of these patients, and 4 of the 6 received enteral fish oil. Standard PN included 2-3 g/kg/d SLE with total PN calories ranging from 57 to 81 kcal/kg/d at the time of SLE removal. Hyperbilirubinemia resolved after elimination of SLE within 1.8-5.4 months. Total PN calories required to maintain growth generally did not change.

CONCLUSIONS

Temporary elimination of SLE and supplementation with enteral fish oil improved cholestasis in PN-dependent infants. Further trials are needed to evaluate this management strategy.

Predicting liver failure in parenteral nutrition-dependent short bowel syndrome of infancy

OBJECTIVES

To test the hypothesis that early trends in common blood tests may delineate risks of liver failure (LF) in infants with parenteral nutrition-associated liver disease (PNALD) from short bowel syndrome and suggest criteria for transplant referral.

STUDY DESIGN

Total levels of bilirubin, gamma-glutamyl transferase, albumin, alanine aminotransferase, platelet count, and absolute neutrophil count were recorded every 3 months for 61 infants with PNALD who were being considered for intestinal transplant starting at age 3 months until death without transplant (n = 12), LF with transplant (n = 35), or liver recovery without transplant (n = 14). Probabilities of LF were determined with logistic regression.

RESULTS

Independent predictors of LF were, in descending order, total bilirubin level (odds ratio [OR] = 1.195), platelet count (OR = 0.992), and albumin level (OR = 0.248). Predicted probabilities of eventual LF varied from 36% to 38% at ages 3 to 6 months when the total bilirubin level was 6.0 mg/dL, platelet count was 220 x 10(3)/microL, and albumin level was 3.5 g/dL to 83% to 84% when the total bilirubin level was 11.7 mg/dL, platelet count was 168 x 10(3)/microL, and albumin level was 3.0 g/dL.

CONCLUSIONS

Transplant referral for a total bilirubin level of 6 mg/dL between 3 to 6 months of age is appropriate, because the probability of LF is at least 36%.

Parenteral fish oil-associated burr cell anemia

We report the development of burr cell anemia in an infant with short bowel syndrome who received parenteral fish oil (Omegaven, Fresenius-Kabi, Graz, Austria) after development of total parenteral nutrition-associated liver disease. Parenteral fish oil was discontinued, and the burr cell anemia disappeared, suggesting that parenteral fish oil might be associated with hemolytic anemia.

Failure of resolution of portal fibrosis during omega-3 fatty acid lipid emulsion therapy in two patients with irreversible intestinal failure

Parenteral omega-3 fatty acid lipid emulsions have been evaluated for their potential role in reversing intestinal failure-associated liver disease. We report our experience using Omegaven in 2 patients with irreversible intestinal failure and intestinal failure-associated liver disease. Despite biochemical and histologic improvement in cholestasis, both patients had persisting, significant portal fibrosis on liver biopsy.

Clinical assessment of the child with intestinal failure

The management of the child with intestinal failure is complex, and it is developing into a multispecialty field of its own led by expert teams of both transplant and nontransplant surgeons, gastroenterologists, and dieticians. Patients are at risk for medical, surgical, and nutritional complications that should be anticipated so that they can be prevented or managed appropriately. Catheter associated infections and intestinal failure associated liver diseases are important complications that impact the likelihood of bowel adaptation and long-term survival. The clinical assessment of a pediatric intestinal failure patient should include evaluation of the child within the context of recognized prognostic factors.

Whole-blood-free choline and choline metabolites in infants who require chronic parenteral nutrition therapy

BACKGROUND AND AIM

Choline deficiency is associated with hepatic dysfunction. Parenteral nutrition (PN) and lipid emulsions contain phosphatidylcholine (PtdCho) but insignificant free choline (FCho). PtdCho is sequentially degraded to glycerolphosphocholine (GPCho), phosphocholine (PCho), and finally to FCho. Biosynthesis of FCho may be insufficient during PN therapy. The aim of the study was to examine the status of FCho and related metabolites in infants on prolonged (> or =4 weeks) PN.

METHODS

Whole blood concentrations of FCho, PtdCho, GPCho, and PCho were measured and compared in infants on PN and infants on enteral feeds (controls).

RESULTS

Infants on PN (n = 14) had higher birth weight but same postnatal age as controls (n = 14) (mean +/- standard deviation) 8.3 +/- 3.9 versus 7.4 +/- 3.6 weeks. Parenteral nutrition was associated with increased PtdCho 1761 +/- 452 versus 1471 +/- 221 nmol/mL, P = 0.04. Mean whole blood FCho, GPCho, and PCho concentrations did not differ significantly in PN versus controls: 40.0 +/- 15.4 versus 50.8 +/- 49.7, 16.4 +/- 14.5 versus 25.2 +/- 29.3, and 15.3 +/- 13.5 versus 22.0 +/- 14.8 nmol/mL, respectively. However, PCho was positively correlated with GPCho in controls (r = 0.91, P < 0.01) but not PN (r = 0.24, P = NS), and infants receiving >90% of daily energy intake from PN (n = 6) had decreased PCho, 5.7 +/- 4.1 nmol/mL, compared with those receiving <90% of daily energy intake (n = 8) 22.5 +/- 13.7 nmol/mL, P < 0.05, and controls, 22.0 +/- 14.8 nmol/mL, P < 0.01.

CONCLUSIONS

Decreased whole-blood concentrations of choline suggest possible evidence of choline deficiency as illustrated by decreased whole-blood PCho. Choline supplementation should be investigated in infants who require prolonged PN, and whole-blood PCho can be used to monitor response.

Parenteral amino acid intakes in critically ill children: a matter of convenience

BACKGROUND

Parenteral and enteral amino acid requirements for nutrition balance and function have not been defined in critically ill children or adults. In addition to playing a role in protein synthesis, amino acids trigger signaling cascades that regulate various aspects of fuel and energy metabolism and serve as precursors for important substrates. Amino acids can also be toxic. In this study, parenteral intakes of essential and nonessential amino acids (EAAs and NEAAs) supplied to critically ill children were assessed as an initial step for further studies aimed at establishing parenteral amino acid requirements.

METHODS

A retrospective review was conducted to assess intakes of parenteral amino acid for 116 critically ill children, and these intakes were compared with EAA intakes recommended by the Institute of Medicine. Because there are no recommended intakes for NEAA, NEAA intakes were compared with mixed muscle protein content in the older children and breast milk amino acid content in the infants.

RESULTS

Parenteral EAAs were provided in amounts that exceeded recommended intakes for healthy children, except for phenylalanine and methionine, which although excessive, were given in less generous amounts. NEAAs were supplied in lower or higher amounts than the content of mixed muscle proteins or breast milk. Parenteral amino acid formulas are limited in taurine, glutamine, and asparagine despite the fact that inflammatory/immune proteins are rich in these amino acids.

CONCLUSIONS

Amino acid composition of parenteral formulas is variable and lacks scientific support. Parenteral amino acid intakes should be based on measured requirements to maintain nutrition and functional balance and on knowledge of toxicity.

Reversal of intestinal failure-associated liver disease in infants and children on parenteral nutrition: experience with 93 patients at a referral center for intestinal rehabilitation

PURPOSE

Intestinal failure (IF)-associated liver disease (IFALD) complicates the treatment of children with IF receiving parenteral nutrition (PN). We hypothesized that prevention or resolution of IFALD was possible in most children and that this would result in improved outcomes.

METHODS

We reviewed prospectively gathered data on all children referred to the intestinal rehabilitation and transplantation center at our institution. Total bilirubin level (TB) was used as the marker for IFALD. Patients were grouped based on TB at referral and at subsequent inpatient stays and outpatient visits. Standard treatment consisted of cycling of PN, limiting lipid infusion, enteral stimulation, use of ursodeoxycholic acid, and surgical intervention when necessary. Outcomes such as mortality, dependence on PN, and need for transplantation were assessed. Statistical analyses were performed using Fisher's exact, Mann-Whitney U, and Wilcoxon signed rank tests.

RESULTS

Ninety-three patients with intestinal failure and on PN were treated at our center from 2003 to 2009. Median age at referral was 5 months (0.5-264 months). Prematurity was a complicating factor in 63 patients and necrotizing enterocolitis was the most common diagnosis. Eighty-two children had short bowel syndrome, whereas the remaining 11 had extensive motility disorders. 97% of children required significant alteration of their PN administration. At referral, 76 of 93 children had TB 2.0 mg/dL or higher, and 17 had TB below 2.0 mg/dL. TB normalized in 57 of 76 children with elevated TB at referral, and TB remained elevated in 19. Normalization of TB was associated with a mortality of 5.2%, and transplantation was needed in 5.2%. Conversely, when TB remained elevated, mortality was 58% (P = .0002 vs TB normalized), and transplantation occurred in 58% owing to failure of surgical and medical rehabilitation.

CONCLUSIONS

Most children referred for treatment of IF have IFALD. A dedicated IF rehabilitation program can reverse IFALD in many children, and this is associated with improved outcome.

Relationship between biopsy-proven parenteralnutrition-associated liver fibrosis and biochemical cholestasis in children with short bowel syndrome

PURPOSE

The aim of the study was to determine the frequency of biochemical cholestasis (direct bilirubin [DB] > or =2 mg/dL) in children with short bowel syndrome and biopsy-proven parenteral nutrition (PN)-associated liver disease and to define predictive factors for the occurrence and degree of hepatic fibrosis.

METHODS

After institutional review board approval, a retrospective review was conducted of patients followed by 2 multidisciplinary intestinal rehabilitation programs between January 1, 2000, and September 30, 2008. Inclusion criteria were exposure to PN (>30 days) and having undergone a liver biopsy. Liver biopsy specimens were graded from 0 to 3 based upon degree of fibrosis in the pathology report. The most recent DB within 10 days before biopsy was recorded.

RESULTS

A total of 66 children underwent 83 liver biopsy procedures. The most common diagnoses included necrotizing enterocolitis (NEC) (36.4%), gastroschisis (22.7%), and intestinal atresia (15.1%). Median age at biopsy was 6.1 months with a median duration of PN of 4.7 months. Of the patients, 70.3% had a history of exposure to parenteral omega-3 lipid emulsion. Of the liver biopsy specimens, 89% (74/83) demonstrated some degree of fibrosis (fibrosis scale 1-3), including 9.6% (8/83) with evidence of cirrhosis. 83% of biopsies without fibrosis and 55% of biopsies with fibrosis were obtained in patients without evidence of biochemical cholestasis (P = .20). Three (37%) of the 8 patients with cirrhosis on liver biopsy had no evidence of biochemical cholestasis. Univariate analysis identified only gestational age (GA) at birth as significantly associated with the degree of liver fibrosis (P = .03). A multivariate logistic regression model accounting for multiple biopsy procedures in patients revealed that GA was a predictor of fibrosis only in patients with a diagnosis other than NEC (P < .01).

CONCLUSIONS

In children with short bowel syndrome, biochemical cholestasis does not reflect the presence or degree of histologically confirmed PN-associated liver fibrosis. Careful follow-up, combined with further refinement of diagnostic and hepatoprotective strategies, may be warranted in this patient population.