The role of enteral nutrition in the reversal of parenteral nutrition-associated liver dysfunction in infants

Parenteral Nutrition, Inflammatory Bowel Disease, and Gut Barrier: An Intricate Plot

Malnutrition poses a critical challenge in inflammatory bowel disease, with the potential to detrimentally impact medical treatment, surgical outcomes, and general well-being. Parenteral nutrition is crucial in certain clinical scenarios, such as with patients suffering from short bowel syndrome, intestinal insufficiency, high-yielding gastrointestinal fistula, or complete small bowel obstruction, to effectively manage malnutrition. Nevertheless, research over the years has attempted to define the potential effects of parenteral nutrition on the intestinal barrier and the composition of the gut microbiota. In this narrative review, we have gathered and analyzed findings from both preclinical and clinical studies on this topic. Based on existing evidence, there is a clear correlation between short- and long-term parenteral nutrition and negative effects on the intestinal system. These include mucosal atrophic damage and immunological and neuroendocrine dysregulation, as well as alterations in gut barrier permeability and microbiota composition. However, the mechanistic role of these changes in inflammatory bowel disease remains unclear. Therefore, further research is necessary to effectively address the numerous gaps and unanswered questions pertaining to these issues.

Current Insights Regarding Intestinal Failure-Associated Liver Disease (IFALD): A Narrative Review

Intestinal failure-associated liver disease (IFALD) is a spectrum of liver disease including cholestasis, biliary cirrhosis, steatohepatitis, and gallbladder disease in patients with intestinal failure (IF). The prevalence of IFALD varies considerably, with ranges of 40-60% in the pediatric population, up to 85% in neonates, and between 15-40% in the adult population. IFALD has a complex and multifactorial etiology; the risk factors can be parenteral nutrition-related or patient-related. Because of this, the approach to managing IFALD is multidisciplinary and tailored to each patient based on the etiology. This review summarizes the current knowledge on the etiology and pathophysiology of IFALD and examines the latest evidence regarding preventative measures, diagnostic approaches, and treatment strategies for IFALD and its associated complications.

Current short bowel syndrome management: An era of improved outcomes and continued challenges

Prior to the late 1960s, pediatric short bowel syndrome was a frequently fatal disease. Currently, pediatric interdisciplinary bowel rehabilitation centers report very high survival rates. The mortality trends, up-to-date definitions, incidence, causes, and clinical manifestations of short bowel syndrome are reviewed. Emphasis is placed upon the nutritional, medical, and surgical advances that have contributed to the dramatic improvement in outcomes for pediatric short bowel syndrome patients. Recent findings and remaining challenges are highlighted.

The role of gastrostomy feeding during intestinal rehabilitation for children with short bowel syndrome

PURPOSE

Following extensive bowel resection, many children with short bowel syndrome (SBS) are routinely offered a placement of gastrostomy tube (G-tube) for feeding. This nutritional pathway is aimed to accommodate the gastric and small bowel motor disturbances related to SBS, and to promote weaning off parenteral nutrition (PN) to achieve enteral autonomy (EA). The aim of this study was to investigate the effect of gastrostomy feeding in outcomes of children with SBS.

METHODS

A retrospective cohort of all SBS children managed at our multidisciplinary Intestinal Rehabilitation Center as part of an Intestinal Rehabilitation Program. SBS was defined as PN dependence for more than six weeks following extensive bowel resection. Patients treated with G-tube feeding were compared with patients without G-tube in terms of PN duration, reaching EA, physical development, and surgical parameters.

RESULTS

A total of 36 SBS patients diagnosed between 2003 and 2022 were included. The most common etiologies included congenital intestinal atresia (31%) and necrotizing enterocolitis (25%). SBS-G-tube (group A) contained 20 children, and SBS (group B) contained 16 children. A total of 21 children reached EA (58%); ten from group A (50%), and 11 from group B (69%) (p > 0.05). Within EA patients, mean PN duration was 49 ± 44 months in group A, and 24 ± 33 months in group B (p > 0.05). Patients who reached EA had 22% longer residual small bowel when compared with PN-dependent patients (p = 0.003). However, the outcomes were adjusted for residual small and large bowel length and percentages, a residual ileocecal valve, and a colon in continuity with no differences between the groups. Two-thirds of children from group A reported G-tube related complications (mechanical, bleeding, or infections). We did not find differences in mean height and weight percentiles between the groups (p > 0.05).

CONCLUSION

We did not find significant advantage of gastrostomy feeding in reaching EA. Because there are surgical and mechanical complications related to this procedure, further prospective studies are required to determine G-tube relevance for children with SBS.

Efficient achievement of enteral autonomy facilitates resolution of liver injury in necrotizing enterocolitis induced short bowel syndrome

Children with short bowel syndrome (SBS) are at high risk for intestinal failure associated liver disease (IFALD). The aim of this retrospective follow-up study was to compare weaning off parenteral nutrition (PN) and IFALD between necrotizing enterocolitis (NEC) and non-NEC induced SBS. Altogether, 77 patients with neonatal SBS treated by our multidisciplinary intestinal failure unit (NEC n = 38, non-NEC SBS n = 39) were included and followed-up at least for 2 years until median age of 10 years (interquartile range, 6.0-16). Occurrence and characteristics of IFALD was assessed with liver biopsies obtained at median age of 3.2 (1.0-6.7) years (n = 62) and serum liver biochemistry. Overall, NEC patients had less end-jejunostomies and autologous intestinal reconstruction surgeries performed compared to non-NEC patients (< 0.05), while remaining small bowel anatomy was comparable between groups. Cumulative weaning off PN was more frequent and duration of PN shorter among NEC patients (P < 0.05). Overall cumulative probability of histological IFALD was lower among NEC patients during whole follow-up period (P = 0.052) and at 10 years (P = 0.024). NEC patients had lower ALT and GGT levels at last follow-up (P < 0.05 for all). In univariate Cox regression analysis, absence of end-jejunostomy, NEC diagnosis, longer remaining small bowel length, multidisciplinary treatment and prematurity were predictive for weaning off PN, while NEC diagnosis and lower birth weight in addition to multidisciplinary care protected from histological IFALD. Neonates with NEC induced SBS reached enteral autonomy earlier than those with non-NEC SBS, which associated with more efficient resolution of histological IFALD among long-term survivors.

Long-term assessment of bilirubin and transaminase trends in pediatric intestinal failure patients during the era of hepatoprotective parenteral nutrition

PURPOSE

This study aimed to characterize the relationship between hepatoprotective parenteral nutrition (PN) dependence and long-term serum liver tests in children with intestinal failure (IF).

METHODS

A retrospective review was performed of children with severe IF (> 90 consecutive days of PN) who were followed from 2012 to 2019 at a multidisciplinary intestinal rehabilitation program. Patients were stratified into three groups based on level of PN dependence at most recent follow up: EN (achieved enteral autonomy), mixed (parenteral and enteral nutrition), and PN (> 75% of caloric intake from PN). PN at any point for this cohort was hepatoprotective, defined as soy-based lipids < 1.5 g/kg/day, combination (soy, medium chain fatty acid, olive and fish oil) lipid emulsion, or fish oil-based lipid emulsion. Kaplan-Meier analysis and a generalized estimating equation (GEE) model were utilized to estimate time to normalization and trends, respectively, of two serum markers of liver health: direct bilirubin (DB) and alanine aminotransferase (ALT).

RESULTS

The study included 123 patients (67 EN, 32 mixed, 24 PN). Median follow up time was 4 years. Based on the Kaplan Meier curve, 100% of EN and mixed group patients achieved normal DB levels by 3 years, while 32% of the PN group had elevated DB levels (Fig. 1). At 5 years, 16% of EN patients had elevated ALT levels compared to 73% of PN patients (p < 0.001, Fig. 2). The PN group's ALT levels were 1.76-fold above normal at 3 years (95%CI 1.48-2.03) and 1.65-fold above normal at 5 years (95%CI 1.33-1.97, Fig. 3).

CONCLUSIONS

While serum bilirubin levels tend to normalize, long-term PN dependence in the era of hepatoprotective PN is associated with a persistent transaminase elevation in an overwhelming majority of patients. These data support continued vigilant monitoring of liver health in children with intestinal failure.

LEVEL OF EVIDENCE

III.

Current strategies for managing intestinal failure-associated liver disease

Introduction: Intestinal failure-associated liver disease (IFALD) refers to hepatic dysfunction that results from prolonged parenteral nutrition (PN) use. IFALD is multifactorial in origin and remains a major cause of morbidity and mortality. Prior to 2004, IFALD was associated with mortality as high as 90% in infants who remained on PN greater than 1 year. The advent of new strategies for intravenous lipid emulsion (ILE) administration and improved catheter care now allow many patients to remain on PN and recover from this once fatal condition. Several additional treatment modalities are often used to further improve outcomes for IFALD patients and they are reviewed here.Areas covered: The etiology of IFALD is presented, as well as the rationale behind the use of ILEs that contain fish oil. Other management strategies are addressed, including the effects of several pharmacologic and nutritional interventions.Expert opinion: Like its etiology, the management of IFALD is multifactorial. Prompt recognition of patients at risk, avoiding macronutrient excess, and preventing central line associated bloodstream infections will improve outcomes. In patients who develop IFALD, the use of fish oil monotherapy seems to be efficacious. The most effective intervention, however, continues to be discontinuation of PN and achieving full enteral feedings.

Intestinal Failure-Associated Liver Disease in Neonates

Intestinal failure-associated liver disease (IFALD) is common in neonates who suffer from intestinal failure and rely on parenteral nutrition. The etiology is multifactorial, relating to the infant's underlying cause of intestinal failure and other infant factors such as prematurity. Management of the disease includes transitioning to enteral feedings as soon as is safe for the infant. In infants who continue to rely on parenteral nutrition, alternative lipid emulsions and other medications may be used. This article reviews the epidemiology and factors that contribute to IFALD in neonates, in addition to management strategies.

Novel Strategies to Prevent Total Parenteral Nutrition-Induced Gut and Liver Inflammation, and Adverse Metabolic Outcomes

Total parenteral nutrition (TPN) is a life-saving therapy administered to millions of patients. However, it is associated with significant adverse effects, namely liver injury, risk of infections, and metabolic derangements. In this review, the underlying causes of TPN-associated adverse effects, specifically gut atrophy, dysbiosis of the intestinal microbiome, leakage of the epithelial barrier with bacterial invasion, and inflammation are first described. The role of the bile acid receptors farnesoid X receptor and Takeda G protein-coupled receptor, of pleiotropic hormones, and growth factors is highlighted, and the mechanisms of insulin resistance, namely the lack of insulinotropic and insulinomimetic signaling of gut-originating incretins as well as the potentially toxicity of phytosterols and pro-inflammatory fatty acids mainly released from soybean oil-based lipid emulsions, are discussed. Finally, novel approaches in the design of next generation lipid delivery systems are proposed. Propositions include modifying the physicochemical properties of lipid emulsions, the use of lipid emulsions generated from sustainable oils with favorable ratios of anti-inflammatory n-3 to pro-inflammatory n-6 fatty acids, beneficial adjuncts to TPN, and concomitant pharmacotherapies to mitigate TPN-associated adverse effects.

Impaired Gut-Systemic Signaling Drives Total Parenteral Nutrition-Associated Injury

BACKGROUND

Total parenteral nutrition (TPN) provides all nutritional needs intravenously. Although lifesaving, enthusiasm is significantly tempered due to side effects of liver and gut injury, as well as lack of mechanistic understanding into drivers of TPN injury. We hypothesized that the state of luminal nutritional deprivation with TPN drives alterations in gut-systemic signaling, contributing to injury, and tested this hypothesis using our ambulatory TPN model.

METHODS

A total of 16 one-week-old piglets were allocated randomly to TPN (n = 8) or enteral nutrition (EN, n = 8) for 3 weeks. Liver, gut, and serum were analyzed. All tests were two-sided, with a significance level of 0.05.

RESULTS

TPN resulted in significant hyperbilirubinemia and cholestatic liver injury, p = 0.034. Hepatic inflammation (cluster of differentiation 3 (CD3) immunohistochemistry) was higher with TPN (p = 0.021). No significant differences in alanine aminotransferase (ALT) or bile ductular proliferation were noted. TPN resulted in reduction of muscularis mucosa thickness and marked gut atrophy. Median and interquartile range for gut mass was 0.46 (0.30-0.58) g/cm in EN, and 0.19 (0.11-0.29) g/cm in TPN (p = 0.024). Key gut-systemic signaling regulators, liver farnesoid X receptor (FXR; p = 0.021), liver constitutive androstane receptor (CAR; p = 0.014), gut FXR (p = 0.028), G-coupled bile acid receptor (TGR5) (p = 0.003), epidermal growth factor (EGF; p = 0.016), organic anion transporter (OAT; p = 0.028), Mitogen-activated protein kinases-1 (MAPK1) (p = 0.037), and sodium uptake transporter sodium glucose-linked transporter (SGLT-1; p = 0.010) were significantly downregulated in TPN animals, whereas liver cholesterol 7 alpha-hydroxylase (CyP7A1) was substantially higher with TPN (p = 0.011).

CONCLUSION

We report significant alterations in key hepatobiliary receptors driving gut-systemic signaling in a TPN piglet model. This presents a major advancement to our understanding of TPN-associated injury and suggests opportunities for strategic targeting of the gut-systemic axis, specifically, FXR, TGR5, and EGF in developing ameliorative strategies.

Intravenous Fish Oil Monotherapy as a Source of Calories and Fatty Acids Promotes Age-Appropriate Growth in Pediatric Patients with Intestinal Failure-Associated Liver Disease

OBJECTIVE

To compare growth in children with intestinal failure-associated liver disease (IFALD) who received a fish oil intravenous lipid emulsion (FOLE) to those who received a soybean oil intravenous lipid emulsion (SOLE).

STUDY DESIGN

This multisite, retrospective study pair-matched FOLE (n = 82) to SOLE recipients (n = 41) using baseline serum direct bilirubin levels and postmenstrual age. Study subjects received open-label FOLE (1 g/kg/day) until IFALD resolved or parenteral nutrition was stopped. Historical control subjects received SOLE (up to 3 g/kg/day). Growth measures (changes in body weight, height/length, and head circumference), prealbumin, triglycerides, and glucose were compared between groups over time using the Wilcoxon rank-sum test.

RESULTS

Although changes in all of the growth measures were similar for both groups (P > .05), FOLE recipients demonstrated an overall improved growth trajectory. After 28 weeks, FOLE recipients had a mean body weight within a z score range of -1 to 1 indicating age-appropriate growth. FOLE recipients consistently had higher prealbumin, lower triglyceride, and more normal glucose concentrations over time compared with SOLE recipients.

CONCLUSIONS

Children with IFALD who received FOLE had similar growth and fewer metabolic abnormalities compared with those who received SOLE.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00910104 and NCT00738101.

Long-Term Outcomes and Disease Burden of Neonatal Onset Short Bowel Syndrome

PURPOSE

The study aims to describe long-term outcomes and disease burden of neonatal onset short bowel syndrome (SBS).

METHODS

Utilizing the WHO criteria for adolescence, patients 10-19 years of age with neonatal onset SBS requiring parenteral nutrition (PN) for >90 days and followed by our multidisciplinary intestinal rehabilitation center between 2009 and 2018 were included for analysis.

RESULTS

Seventy adolescents with SBS were studied. Median (IQR) age at last follow up in our center was 15 (11, 17) years. There was 0% mortality in the cohort, and 94% remained transplant free. Fifty-three patients (76%) achieved enteral autonomy. Three patients were weaned from PN without transplantation after six years of follow-up and another four after ten years of care at our multidisciplinary center. Disease burden remained higher in adolescents receiving PN, including inpatient hospitalizations (p < 0.01), procedures (p = 0.01), clinic visits (p < 0.01), and number of prescribed medications (p < 0.01).

CONCLUSION

Survival for adolescents with neonatal onset SBS is excellent. Of the cohort studied, there was no mortality, and more than 75% achieved enteral autonomy. Disease burden remains high for adolescents who remain dependent on PN. However, achievement of enteral autonomy is feasible with long-term multidisciplinary rehabilitation.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level II.

Mechanisms of Parenteral Nutrition-Associated Liver and Gut Injury

Parenteral nutrition (PN) has revolutionized the care of patients with intestinal failure by providing nutrition intravenously. Worldwide, PN remains a standard tool of nutrition delivery in neonatal, pediatric, and adult patients. Though the benefits are evident, patients receiving PN can suffer serious cholestasis due to lack of enteral feeding and sometimes have fatal complications from liver injury and gut atrophy, including PN-associated liver disease or intestinal failure-associated liver disease. Recent studies into gut-systemic cross talk via the bile acid-regulated farnesoid X receptor (FXR)-fibroblast growth factor 19 (FGF19) axis, gut microbial control of the TGR5-glucagon-like peptide (GLP) axis, sepsis, and role of prematurity of hepatobiliary receptors are greatly broadening our understanding of PN-associated injury. It has also been shown that the composition of ω-6/ω-3 polyunsaturated fatty acids given parenterally as lipid emulsions can variably drive damage to hepatocytes and cell integrity. This manuscript reviews the mechanisms for the multifactorial pathogenesis of liver disease and gut injury with PN and discusses novel ameliorative strategies.

Use of Fish Oil Intravenous Lipid Emulsions as Monotherapy in the Pediatric Intestinal Failure Patient: Beyond the Package Insert

In July 2018, an intravenous lipid emulsion (ILE) composed of 100% fish oil (Omegaven, Fresenius Kabi, Bad Homburg, Germany) received Food and Drug Administration (FDA) approval as a source of fatty acids and calories for infants and children with parenteral nutrition-associated cholestasis. This soy-free fat source is rich in ω-3 fatty acids and α-tocopherol and contains few phytosterols. In comparison to conventional soybean oil ILE, this emulsion appears to be less hepatotoxic. The purpose of this paper is to guide the practitioner on the use of this alternative fat source in clinical practice and augment the material contained in the current package insert. This paper addresses various topics including the identification of which patients would benefit from fish oil ILE, dosing, administration, monitoring, potential adverse effects, and management strategies for fish oil ILE.

Premature Lambs Exhibit Normal Mitochondrial Respiration after Long-Term Extrauterine Support

BACKGROUND

In an effort to mitigate the major morbidities and mortality associated with extreme prematurity, we have developed an EXTrauterine Environment for Neonatal Development (EXTEND) designed to provide physiologic support of extremely premature infants.

OBJECTIVES

We have previously shown that long-term, physiologic support of premature fetal lambs is possible with EXTEND, but in this study, we sought to demonstrate bioenergetic equipoise at the tissue level.

METHODS

Four premature fetal lambs were delivered by hysterotomy at gestational ages (GA) of 105-107 days (term ∼145 days), cannulated via the umbilical vessels, and transitioned to support on EXTEND for 3-4 weeks. Five control fetuses were age-matched to the GA of experimental fetuses at the time of study end (128-134 days GA) and immediately sacrificed after hysterotomy. Mitochondria were isolated from the heart, liver, kidney, and skeletal muscle of fetuses at the time of sacrifice, and oxygen consumption rates (OCRs) were measured.

RESULTS

There were no differences in basal mitochondrial OCR between EXTEND and control fetuses for heart, kidney, or skeletal muscle. For liver, the basal OCR was higher in EXTEND fetuses compared to controls. There were no differences in physiologic maximal OCR or reserve capacity for any tissue analyzed.

CONCLUSIONS

Fetal lambs supported by EXTEND demonstrate physiologic mitochondrial function as evidenced by adequate basal and physiologic maximal cellular respiration as well as preserved reserve capacity.

Role of the Gut⁻Liver Axis in Driving Parenteral Nutrition-Associated Injury

For decades, parenteral nutrition (PN) has been a successful method for intravenous delivery of nutrition and remains an essential therapy for individuals with intolerance of enteral feedings or impaired gut function. Although the benefits of PN are evident, its use does not come without a significant risk of complications. For instance, parenteral nutrition-associated liver disease (PNALD)—a well-described cholestatic liver injury—and atrophic changes in the gut have both been described in patients receiving PN. Although several mechanisms for these changes have been postulated, data have revealed that the introduction of enteral nutrition may mitigate this injury. This observation has led to the hypothesis that gut-derived signals, originating in response to the presence of luminal contents, may contribute to a decrease in damage to the liver and gut. This review seeks to present the current knowledge regarding the modulation of what is known as the “gut–liver axis” and the gut-derived signals which play a role in PN-associated injury.

No Gut No Gain! Enteral Bile Acid Treatment Preserves Gut Growth but Not Parenteral Nutrition-Associated Liver Injury in a Novel Extensive Short Bowel Animal Model

BACKGROUND

Parenteral nutrition (PN) provides nutrition intravenously; however, this life-saving therapy is associated with significant liver disease. Recent evidence indicates improvement in PN-associated injury in animals with intact gut treated with enteral bile acid (BA), chenodeoxycholic acid (CDCA), and a gut farnesoid X receptor (FXR) agonist, which drives the gut-liver cross talk (GLCT). We hypothesized that similar improvement could be translated in animals with short bowel syndrome (SBS).

METHODS

Using piglets, we developed a novel 90% gut-resected SBS model. Fifteen SBS piglets receiving PN were given CDCA or control (vehicle control) for 2 weeks. Tissue and serum were analyzed posteuthanasia.

RESULTS

CDCA increased gut FXR (quantitative polymerase chain reaction; P = .008), but not downstream FXR targets. No difference in gut fibroblast growth factor 19 (FGF19; P = .28) or hepatic FXR (P = .75), FGF19 (P = .86), FGFR4 (P = .53), or Cholesterol 7 α-hydroxylase (P = .61) was noted. PN resulted in cholestasis; however, no improvement was noted with CDCA. Hepatic fibrosis or immunostaining for Ki67, CD3, or Cytokeratin 7 was not different with CDCA. PN resulted in gut atrophy. CDCA preserved (P = .04 vs control) gut mass and villous/crypt ratio. The median (interquartile range) for gut mass for control was 0.28 (0.17-0.34) and for CDCA was 0.33 (0.26-0.46).

CONCLUSIONS

We note that, unlike in animals with intact gut, in an SBS animal model there is inadequate CDCA-induced activation of gut-derived signaling to cause liver improvement. Thus, it appears that activation of GLCT is critically dependent on the presence of adequate gut. This is clinically relevant because it suggests that BA therapy may not be as effective for patients with SBS.

Long-term outcomes of pediatric intestinal failure

Management of pediatric intestinal failure has evolved in recent decades, with improved survival since the advent of specialized multidisciplinary intestinal failure centers. Though sepsis and intestinal failure associated liver disease still contribute to mortality, we now have growing data on the long-term outcomes for this population. While intestinal adaptation and parenteral nutrition weaning is most rapid during the first year on parenteral support, achievement of enteral autonomy is possible even after many years as energy and protein requirements decline dramatically with age. Intestinal transplant is an option for patients experiencing complications of long-term parenteral nutrition who are expected to have permanent intestinal failure, but outcomes are hindered by immunosuppression-related complications. Much of the available data comes from single center retrospective reports, with variable inclusion criteria, intestinal failure definitions, and follow-up durations; this limits the ability to analyze outcomes and identify best practices. As most children now survive long-term, the focus of management has shifted to the avoidance and management of comorbidities, support of normal growth and development, and optimization of quality of life for these medically and surgically complex patients.

Pathophysiology, prevention, treatment, and outcomes of intestinal failure-associated liver disease

BACKGROUND

Intestinal failure-associated liver disease (IFALD) remains a serious problem in the treatment of infants with nutritional problems and short bowel syndrome.

METHODS

A review of the recent literature from 2010 to 2016, concentrating on articles related to the pathophysiology of IFALD and to outcomes of novel nutritional and pharmacological therapies for neonatal cholestasis in the post-surgical neonate.

RESULTS

The pathophysiology of IFALD relates to an increase sensitivity of the neonatal liver to cholestasis in the non-fed state; prolonged cholestasis almost inevitably results in liver damage which will progress from fibrosis to cirrhosis. Clinically discerned risk factors include premature birth, inflammation, sepsis, disruption of the enterohepatic circulation by creation of a proximal stoma, and the duration and type of parenteral nutritional support. Within the hepatocyte, the regulatory enzyme farsanoid receptor X (FXR) appears to play a pivotal role in the development of cholestasis. Recent studies have shown that its activity is suppressed by sepsis, and by plant phytosterols found in soy-based lipid preparations. This paradigm is reflected in the emerging consensus for the care of post-surgical neonates, which is based around a multi-disciplinary team approach. Using an algorithm-driven approach, an appropriate balance between caloric support and prevention of IFALD can be achieved.

CONCLUSIONS

Further prospective studies are required to further refine the optimal sequence of use of these therapies and the long-term effects on neurological development and hepatic function. However, with optimal care, the number of IF patients progressing to end-stage liver disease because of IFALD should be very low.

Preserved Gut Microbial Diversity Accompanies Upregulation of TGR5 and Hepatobiliary Transporters in Bile Acid-Treated Animals Receiving Parenteral Nutrition

BACKGROUND

Parenteral nutrition (PN) is a lifesaving therapy but is associated with gut atrophy and cholestasis. While bile acids (BAs) can modulate intestinal growth via gut receptors, the gut microbiome likely influences gut proliferation and inflammation. BAs also regulate the bile salt export pump (BSEP) involved in cholestasis. We hypothesized that the BA receptor agonist oleanolic acid (OA) regulates gut TGR5 receptor and modulates gut microbiota to prevent PN-associated injury.

MATERIALS AND METHODS

Neonatal piglets were randomized to approximately 2 weeks of isocaloric enteral nutrition (EN), PN, or PN + enteral OA. Serum alanine aminotransferase, bilirubin, BAs, hepatic BSEP, gut TGR5, gut, liver morphology, and fecal microbiome utilizing 16S rRNA sequencing were evaluated. Kruskal-Wallis test, pairwise Mann-Whitney U test, and multilevel logistic regression analysis were performed.

RESULTS

PN support resulted in gut atrophy substantially prevented by OA. The median (interquartile range) for villous/crypt ratio was as follows: EN, 3.37 (2.82-3.80); PN, 1.73 (1.54-2.27); and OA, 2.89 (2.17-3.34; P = .006). Pairwise comparisons yielded P = .002 (EN vs PN), P = .180 (EN vs OA), P = .026 (PN vs OA). OA upregulated TGR5 and BSEP without significant improvement in serum bilirubin ( P = .095). A decreased microbial diversity and shift toward proinflammatory phylum Bacteroidetes were seen with PN, which was prevented by OA.

CONCLUSIONS

OA prevented PN-associated gut mucosal injury, Bacterioides expansion, and the decreased microbial diversity noted with PN. This study demonstrates a novel relationship among PN-associated gut dysfunction, BA treatment, and gut microbial changes.

Risk factor analysis of parenteral nutrition-associated cholestasis in extremely low birth weight infants

AIM

Parenteral nutrition (PN) provides an alternative nutrition source for preterm infants who are intolerant of enteral nutrition. However, prolonged PN increases the risk of PN-associated cholestasis (PNAC). We conducted this study to determine the incidence and risk factors of PNAC in extremely low birth weight (ELBW) infants.

METHODS

We retrospectively reviewed the medical records of ELBW infants from March 2010 to April 2015. PNAC was diagnosed in infants with a history of PN for at least two weeks and direct bilirubin concentrations >2 mg/dL after other causes of neonatal cholestasis were excluded.

RESULTS

Of the 114 eligible ELBW infants, 41 (36%) were diagnosed with PNAC. The multivariate analysis showed that birth weight, sepsis, necrotising enterocolitis, fluconazole prophylaxis and the duration of PN and hospitalisation were independent risk factors for the development of PNAC (p < 0.05). However, parenteral fish oil-based lipid preparation (FOLP) did not reduce the risk of PNAC. Although PNAC was not a direct cause of death, it was associated with an increased risk of mortality.

CONCLUSION

PNAC was common in ELBW infants, was associated with various clinical factors and increased the risk of mortality. However, we did not observe the protective effect of FOLP against PNAC.

Enteral autonomy, cirrhosis, and long term transplant-free survival in pediatric intestinal failure patients

PURPOSE

Patient selection for transplant evaluation in pediatric intestinal failure is predicated on the ability to assess long-term transplant-free survival. In light of trends toward improved survival of intestinal failure patients in recent decades, we sought to determine if the presence of biopsy-proven hepatic cirrhosis or the eventual achievement of enteral autonomy were associated with transplant-free survival.

METHODS

After IRB approval, records of all pediatric intestinal failure patients (parenteral nutrition (PN) >90 days) treated at a single intestinal failure center from February 2002 to September 2014 were reviewed. Chi-squared, Mann-Whitney, and log-rank testing were performed as appropriate.

RESULTS

Of 313 patients, 174 eventually weaned off PN. Liver biopsies were available in 126 patients (most common indication was intestinal failure associated liver disease, IFALD), and 23 met histologic criteria for cirrhosis. Transplant-free survival for the whole cohort of 313 patients was 94.7% at 1 year and 89.2% at 5 years. Among patients with liver biopsies, transplant-free survival in cirrhotics vs. noncirrhotics was 95.5% vs. 94.1% at one year and 95.5% vs. 86.7% at 5 years (P=0.29). Transplant-free survival in patients who achieved enteral autonomy compared with patients who remained PN dependent was 98.2% vs. 90.3% at one year and 98.2% vs. 76.9% at 5 years (P<0.001). There was no association between cirrhosis and eventual enteral autonomy (P=0.88).

CONCLUSIONS

Achieving enteral autonomy was associated with improved transplant-free survival in pediatric intestinal failure patients. There was no association between histopathological diagnosis of cirrhosis and transplant-free survival in the cohort. These data suggest that automatic transplant referral may not be required for histopathological diagnosis of cirrhosis alone, and that ongoing efforts aimed at achievement of enteral autonomy remain paramount in pediatric intestinal failure.

Parenteral nutrition-associated liver disease in extremely low-birthweight infants with intestinal disease

BACKGROUND

The aim of this study was to investigate factors associated with the development of parenteral nutrition-associated liver disease (PNALD) and to examine the clinicopathological relationship of PNALD in extremely low-birthweight infants (ELBWI).

METHODS

The subjects were 13 ELBWI who had received PN because of intestinal perforation or functional ileus between 2000 and 2013. We measured the serum levels of biochemical parameters, including aspartate aminotransferase, alanine aminotransferase, and direct bilirubin. Liver histopathology was examined in relation to outcome. The subjects were categorized into two groups on liver histopathology: F(+), development of hepatic fibrosis and necrosis with/without cholestasis; and F(-), no hepatic fibrosis.

RESULTS

Of 13 ELBWI, five died of hepatic failure, five died of sepsis, and the other three were alive at the time of the study. Of the five infants who died of hepatic failure, two developed fulminant hepatitis without cholestasis, and the other three developed chronic cholestasis and finally hepatic failure. Postmortem histopathology in F(+) indicated not only massive hepatic necrosis, but also massive hepatic fibrosis. These histopathological findings explained the clinical presentation of portal hypertension. There were significant differences in the fasting period after intestinal disease onset between the two groups.

CONCLUSION

The prolonged fasting with PN is responsible for severe hepatocellular necrosis with fibrosis and consequent lethal portal hypertension.

Controversies in the Mechanism of Total Parenteral Nutrition Induced Pathology

Over 30,000 patients are permanently dependent on Total Parenteral Nutrition (TPN) for survival with several folds higher requiring TPN for a prolonged duration. Unfortunately, it can cause potentially fatal complications. TPN infusion results in impairment of gut mucosal integrity, enhanced inflammation, increased cytokine expression and trans-mucosal bacterial permeation. It also causes endotoxin associated down regulation of bile acid transporters and Parenteral Nutrition Associated Liver Disease (PNALD), which includes steatosis, disrupted glucose metabolism, disrupted lipid metabolism, cholestasis and liver failure. Despite multiple theories, its etiology and pathophysiology remains elusive and is likely multifactorial. An important cause for TPN related pathologies appears to be a disruption in the normal enterohepatic circulation due to a lack of feeding during such therapy. This is further validated by the fact that in clinical settings, once cholestasis sets in, its reversal occurs when a patient is receiving a major portion of calories enterally. There are several other postulated mechanisms including gut bacterial permeation predisposing to endotoxin associated down regulation of bile acid transporters. An additional potential mechanism includes toxicity of the TPN solution itself, such as lipid mediated hepatic toxicity. Prematurity, leading to a poor development of bile acid regulating nuclear receptors and transporters has also been implicated as a causative factor. This review presents the current controversies and research into mechanisms of TPN associated injury.

Oleanolic Acid Improves Gut Atrophy Induced by Parenteral Nutrition

BACKGROUND

Nutrition support with parenteral nutrition (PN) is associated with gut atrophy. Prior studies have shown improvement with enteral chenodeoxycholic acid, a dual agonist for the farnesoid X receptor (FXR) and bile acid receptor TGR5. We hypothesized that gut growth is induced by TGR5 activation, and gut atrophy during PN administration could be prevented with the TGR5-specific agonist oleanolic acid (OA).

METHODS

Neonatal pigs were implanted with duodenal and jugular vein catheters. Animals were provided equi-nutritious PN or enteral swine milk. A PN subgroup received enteral OA at 50 mg/kg/d.

RESULTS

PN caused marked gut atrophy compared with enterally fed (EN) control animals. OA treatment led to preservation of gut mass demonstrated grossly and histologically. The mean ± SD gut weight as a percentage of body weight was 4.30 ± 0.26 for EN, 1.92 ± 0.06 for PN (P < .05, EN vs PN), and 3.39 ± 0.79 for PN+OA (P < .05, PN+OA vs PN). Mean ± SD gut density (g/cm) was 0.31 ± 0.03 for EN, 0.18 ± 0.03 for PN (P < .05 EN vs PN), and 0.27 ± 0.01 for PN+OA (P < .05 PN+OA vs PN). Histologically, a markedly decreased villous to crypt ratio was noted with PN, and OA significantly prevented this decrease. The mean ± SD v/c ratio was 3.51 ± 0.59 for EN, 1.69 ± 0.10 for PN (P < .05, EN vs PN), and 2.90 ± 0.23 for PN+OA (P < .05, PN+OA vs PN). Gut TGR5 messenger RNA expression was significantly elevated with OA treatment compared with both PN and EN.

CONCLUSION

The bile acid-activated G protein-coupled receptor TGR5 agonist OA prevented gut atrophy associated with PN.

Early enteral and parenteral nutritional support after hepatectomy in patients with hepatic carcinoma: a systematic review and meta-analysis

Background

This study sought to conduct a systematic review providing a comparative analysis of enteral nutrition (EN) and parenteral nutrition (PN) after hepatectomy.

Methods

PubMed, Embase, and the China National Knowledge Infrastructure databases were searched for publications describing randomized controlled trials that compared early EN and PN after hepatectomy. The time period for this search was from January 1990 to December 2013. In accordance with the inclusion criteria of this study, two researchers independently screened the retrieved literature, extracted data, and assessed methodological quality. A meta-analysis of the included publications was then performed using RevMan 5.2 software.

Results

The meta-analysis results indicated statistically significant differences between the group that received EN and the group that received PN during the early stages after hepatectomy with respect to average total bilirubin and alanine aminotransferase levels after nutrition, pre-albumin levels, incidence of diarrhea and abdominal bloating, time to flatus, and average cost of nutrition. To varying degrees, better results were observed in the EN group than in the PN group for these metrics.

Conclusion

During the early stages after hepatectomy, EN has obvious advantages relative to PN; thus, EN merits more widespread promotion and application in this clinical context.

Preservation of biochemical liver function with low-dose soy-based lipids in children with intestinal failure-associated liver disease

OBJECTIVES

Intestinal failure-associated liver disease (IFALD) contributes to significant morbidity in pediatric patients with intestinal failure (IF); however, the use of parenteral nutrition (PN) with a fish oil-based intravenous (IV) emulsion (FO) has been associated with biochemical reversal of cholestasis and improved outcomes. Unfortunately, FO increases the complexity of care: because it can be administered only under Food and Drug Administration compassionate use protocols requiring special monitoring, it is not available as a 3-in-1 solution and is more expensive than comparable soy-based IV lipid emulsion (SO). Because of these pragmatic constraints, a series of patient families were switched to low-dose (1 g kg(-1) day(-1)) SO following biochemical resolution of cholestasis. The present study examines whether reversal of cholestasis and somatic growth are maintained following this transition.

METHODS

The present study is a chart review of all children with IFALD who switched from FO to SO following resolution of cholestasis. Variables are presented as medians (interquartile ranges). Comparisons were performed using the Wilcoxon signed-rank test.

RESULTS

Seven patients ages 25.9 (16.2-43.2) months were transitioned to SO following reversal of cholestasis using FO. At a median follow-up of 13.9 (4.3-50.1) months, there were no significant differences between pretransition and post-transition serum alanine and aspartate aminotransferases, direct bilirubin, and weight-for-age z scores. Because of recurrence of cholestasis, 1 patient was restarted on FO after 4 months on SO.

CONCLUSIONS

Biochemical reversal of IFALD and growth were preserved after transition from FO to SO in 6 of 7 (86%) patients. Given the challenges associated with the use of FO, SO may be a viable alternative in select patients with home PN.

Low-fat, high-carbohydrate parenteral nutrition (PN) may potentially reverse liver disease in long-term PN-dependent infants

INTRODUCTION

Parenteral nutrition-associated cholestasis (PNAC) is a complication of long-term parenteral nutrition (PN). Removal of lipids may reverse PNAC but compromises the energy to ensure infant growth. The purpose of this study was to test whether a low-fat, high-carbohydrate PN regimen, which prevents and reverses PNAC in adults, could do the same in infants. This regimen could potentially avoid the problem of diminished energy input after removing nutritional lipids.

METHODS

Infants developing PNAC over a 2-year period were started on a low-fat PN regimen with calories primarily from carbohydrates. The fat-free PN, containing 314 kJ/ml, was provided 5-6 times a week and fat, including essential fatty acids and fat-soluble vitamins, 1-2 times a week. Enteral feeding was continued according to individual tolerance.

RESULTS

The study included 10 infants with short bowel syndrome (six with intestinal failure due to necrotizing enterocolitis, one with gastroschisis, one with complications due to unrecognized anal atresia and two with midgut volvulus). Median duration of PN with fat before initiating the low-fat regime was 69 days (25-75 % percentile: 41-75 days), and mean s-bilirubin was 139 µmol/l (range 87-323 µmol/l). Median duration with low-fat regimen was 69 days (25-75 % percentile: 18-123 days). Bilirubin reversed to normal (<50 µmol/l) in all infants. Seven children showed catch-up growth. No essential fatty acid deficiency, steatosis or deaths were observed.

CONCLUSIONS

A low-fat, high-carbohydrate PN regimen together with enteral feeding is well tolerated and may be used in reversing liver disease in PN-dependent infants without compromising growth.

Effects of two kinds of enteral nutrition preparations on liver regeneration and function in mice after partial hepatectomy

AIM: To investigate the effects of two kinds of enteral nutrition preparations on liver regeneration and function in mice after partial hepatectomy (PH).

METHODS: A mouse model of oral enteral nutrition (EN) after 70%PH was used in this study. Seventy-two male ICR mice were randomly divided into a PH control group (routine diet after PH), a TP-MCT group (EN with TP-MCT after PH) and a SP group (EN with Peptisorb after PH). Serum samples and liver tissue specimens were collected 1, 3 and 7 d after PH. Serum samples were used to measure the levels of alanine aminotransferase (ALT), aspartate transaminase (AST), albumin, interleukin-6 (IL-6) and IL-10. The liver tissue specimens were used to measure the proliferation of hepatocytes and the morphology of liver tissue by immunohistostaining and HE staining.

RESULTS: In comparison with the PH control group, serum levels of ALT and AST on days 1, 3 and 7 decreased significantly in the TP-MCT group and SP group (P < 0.05 for all). Compared with the PH control group, the level of IL-6 on day 1 decreased significantly in the TP-MCT group and SP group, but the level of IL-10 increased significantly in the TP-MCT group and SP group (P < 0.05 for all). Liver regeneration was enhanced significantly on days 1, 3 and 7 in the TP-MCT group and SP group, especially in the SP group.

CONCLUSION: Enteral nutrition can well protect mouse liver function and promote liver regeneration after PH, with SP (Peptisorb) having a better effect.

Use of Fish Oil-Based Lipid Emulsions in Infants With Intestinal Failure-Associated Liver Disease: A Case Series

The use of fish oil-based lipid emulsions (FOLE) in the treatment of intestinal failure-associated liver disease (IFALD) remains investigational. Additional evidence for safety and efficacy, particularly in the neonatal and pediatric populations, is needed. Retrospective chart review was conducted on 10 infants with short bowel syndrome who received FOLE for IFALD. Direct bilirubin concentrations normalized in surviving subjects within 4.1 to 22.7 weeks of starting treatment. Although earlier initiation of FOLE was not associated with more rapid normalization of direct bilirubin concentrations, it trended toward a significant correlation with reduced length of hospital stay (P = .058). The reduction in direct bilirubin levels and transition from parenteral to enteral feeding were statistically significant within 6 weeks of initiating the FOLE. Subjects did not have impaired growth and did not develop an essential fatty acid deficiency. These infants were discharged from the hospital 7.9 to 42.3 weeks after starting FOLE treatment, and 2 infants had transitioned completely off parenteral nutrition at discharge. In this study, FOLE appeared to be a safe and effective treatment for IFALD in infants with short bowel syndrome. Future studies are necessary to determine whether FOLE can help to prevent or shorten the duration of cholestasis.

CANDIDATE GENES FOR LIMITING CHOLESTATIC INTESTINAL INJURY IDENTIFIED BY GENE EXPRESSION PROFILING

The lack of bile flow from the liver into the intestine can have devastating complications including hepatic failure, sepsis and even death. This pathologic condition known as cholestasis can result from etiologies as diverse as total parenteral nutrition (TPN), hepatitis and pancreatic cancer. The intestinal injury associated with cholestasis has been shown to result in decreased intestinal resistance, increased bacterial translocation and increased endotoxemia. Anecdotal clinical evidence suggests a genetic predisposition to exaggerated injury. Recent animal research on two different strains of inbred mice demonstrating different rates of bacterial translocation with different mortality rates supports this premise. In this study, a microarray analysis of intestinal tissue following common bile duct ligation (CBDL) performed under general anesthesia on these same two strains of inbred mice was done with the goal of identifying the potential molecular mechanistic pathways responsible. Over 500 genes were increased more than 2.0 fold following CBDL. The most promising candidate genes included MUPs, Serpina1a and LCN-2. RT-PCR validated the microarray results for these candidate genes. In an in vitro experiment using differentiated intestinal epithelial cells, inhibition of MUP-1 by siRNA resulted in increased intestinal epithelial cell permeability. Diverse novel mechanisms involving the growth hormone pathway, the acute phase response and the innate immune response are thus potential avenues for limiting cholestatic intestinal injury. Changes in gene expression were at times found to be not only due to the CBDL but also due to the murine strain. Should further studies in cholestatic patients demonstrate inter-individual variability similar to what we have shown in mice, then a "personalized medicine" approach to cholestatic patients may become possible.

Incidence, prevention, and treatment of parenteral nutrition-associated cholestasis and intestinal failure-associated liver disease in infants and children: a systematic review

BACKGROUND

Cholestasis is a significant life-threatening complication in children on parenteral nutrition (PN). Strategies to prevent/treat PN-associated cholestasis (PNAC) and intestinal failure-associated liver disease (IFALD) have reached moderate success with little supporting evidence. Aims of this systematic review were (1) to determine the incidence of PNAC/IFALD in children receiving PN for ≥ 14 days and (2) to review the efficacy of measures to prevent/treat PNAC/IFALD.

METHODS

Of 4696 abstracts screened, 406 relevant articles were reviewed, and studies on children with PN ≥ 14 days and cholestasis (conjugated bilirubin ≥ 2 mg/dL) were included. Analyzed parameters were (1) PNAC/IFALD incidence by decade and by PN length and (2) PNAC/IFALD prevention and treatment (prospective studies).

RESULTS

Twenty-three articles (3280 patients) showed an incidence of 28.2% and 49.8% of PNAC and IFALD, respectively, with no evident alteration over the last decades. The incidence of PNAC was directly proportional to the length of PN (from 15.7% for PN ≤ 1 month up to 60.9% for PN ≥ 2 months; P < .0001). Ten studies on PNAC met inclusion criteria. High or intermediate-dose of oral erythromycin and aminoacid-free PN with enteral whey protein gained significant benefits in preterm neonates (P < .05, P = .003, and P < .001, respectively). None of the studies reviewed met inclusion criteria for treatment.

CONCLUSIONS

The incidence of PNAC/IFALD in children has no obvious decrease over time. PNAC is directly correlated to the length of PN. Erythromycin and aminoacid-free PN with enteral whey protein have shown to prevent PNAC in preterm neonates. There is a lack of high-quality prospective studies, especially on IFALD.

Acute cholecystitis in the late phase of severe acute pancreatitis: a neglected problem

OBJECTIVE

This study aimed to evaluate the incidence and risk factors for acute cholecystitis (AC) in the late phase of severe acute pancreatitis (SAP).

METHODS

A review of patients with SAP from January 2008 to December 2009 was performed. Clinical characteristics were compared between patients with AC in the late phase and those without. Risk factors for AC were analyzed using a logistic regression analysis. Receiver operating characteristic curve was used to estimate the predictive value of the risk factors.

RESULTS

A total of 269 cases were included. Twenty-seven episodes of AC in the late phase were identified. Patients with AC had higher computed tomography severity index and Acute Physiology and Chronic Health Evaluation (APACHE) II score, as well as higher rate of intraabdominal hypertension, infective pancreatic necrosis (IPN) of the pancreas head, fistula, abdominal bleeding, mechanical ventilation, and prolonged enteral nutrition (EN) via jejunal tube. Independent risk factors for AC, based on the results of logistic regression analysis, included higher APACHE II score, prolonged EN via jejunal tube, and IPN of the pancreas head.

CONCLUSIONS

Approximately 10% of patients with SAP will develop AC in the late phase. Risk factors include higher APACHE II score, prolonged EN via jejunal tube, and IPN of the pancreas head.

Parenteral-nutrition-associated liver disease after intestinal perforation in extremely low-birthweight infants: consequent lethal portal hypertension

BACKGROUND

Parenteral nutrition (PN)-associated liver dysfunction (PNALD) in term infants usually manifests as intrahepatic cholestasis, which recovers with enteral nutrition (EN) in most cases; however, as the number of extremely low-birthweight infants (ELBWI) has been increasing, and consequently intestinal diseases associated with ELBWI have been increasing, more intractable PNALD has been encountered after surgical treatment in ELBWI, which does not resolve or rather worsens with EN.

METHODS

Three cases of ELBWI with intestinal perforation, which developed PNALD and eventually died of hepatic failure with intractable portal hypertension, were reviewed. Their gestational age and birthweight ranged from 23 to 26 weeks, and from 434 to 968 g, respectively. The intestinal diseases included necrotizing enteritis in two and meconium-related ileus with focal intestinal perforation in one.

RESULTS

The duration of total PN without EN in the three cases was 17, 24 and 24 days, respectively. The interval between the introduction of PN and the onset of PNALD was 14, 4 and 18 days, respectively. A marked elevation of serum endotoxin level was detected in both cases of necrotizing enteritis. Histopathological study of the liver revealed marked cholestasis, significant hepatic necrosis with fibrosis, and proliferation of ductules in all these cases, which was responsible for portal hypertension.

CONCLUSIONS

PN after gastrointestinal disorders in ELBWI may cause refractory PNALD, which does not resolve, or rather worsens with the resumption of EN. Portal hypertension secondary to hepatic necrosis may be responsible for the exacerbation with the resumption of EN.

What really causes necrotising enterocolitis?

Background. One of the most serious gastrointestinal disorders occurring in neonates is necrotising enterocolitis (NEC). It is recognised as the most common intra-abdominal emergency and is the leading cause of short bowel syndrome. With extremely high mortality and morbidity, this enigmatic disease remains a challenge for neonatologists around the world as its definite aetiology has yet to be determined. As current medical knowledge stands, there is no single well-defined cause of NEC. Instead, there are nearly 20 risk factors that are proposed to increase the likelihood of developing NEC. Aims and Objectives. The aim of this project was to conduct a comprehensive literature review around the 20 or so well-documented and less well-documented risk factors for necrotising enterocolitis. Materials and Methods. Searches of the Medline, Embase, and Science direct databases were conducted using the words "necrotising enterocolitis + the risk factor in question" for example, "necrotising enterocolitis + dehydration." Search results were ordered by relevance with bias given to more recent publications. Conclusion. This literature review has demonstrated the complexity of necrotising enterocolitis and emphasised the likely multifactorial aetiology. Further research is needed to investigate the extent to which each risk factor is implicated in necrotising enterocolitis.

Fish oil emulsions in the management of intestinal failure-associated liver disease

The role of parenteral lipid emulsions in the treatment of intestinal failure-associated liver disease (IFALD) is both topical and controversial. There is strong evidence supporting plant-based (soy, olive) lipid emulsions as a key cause for IFALD, especially in neonates. As a result, alternate lipid formulations, most notably fish oil emulsions (FOE) have come into widespread use despite somewhat limited clinical data on their overall benefit and potential long-term consequences. This review examines putative mechanisms of action of FOE in reversing cholestasis associated with IFALD, and critically reviews published clinical studies of the use of FOE in pediatric patients with IFALD. From these works, it appears the mechanism of action of FOE is most likely related to the reduction of serum phytosterols associated with plant-based lipid emulsions rather than a specific positive benefit of the fish oils themselves. Although the use of FOE seems to correlate with a reduction in cholestasis, their actual individual benefit is not established, and data on long-term outcomes and safety are not yet available.

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.

Review and clinical update on parenteral nutrition-associated liver disease

Parenteral nutrition-associated liver disease (PNALD) is a complex disease that is diagnosed by clinical presentation, biochemical markers of liver injury, concurrent use of parenteral nutrition (PN), and negative workup for other causes of liver disease. Since the first case of PNALD was reported more than 30 years ago, clinicians have had few effective treatments for PNALD, and when disease progressed to liver cirrhosis, it was historically associated with poor outcomes. Within the past 5 years, there has been much excitement about new treatments for PNALD, including use of both parenteral and enteral ω-3 polyunsaturated long-chain fatty acids (ω-3 PUFA) as well as restricting dosing of ω-6 PUFA. Scientists are also interested in uncovering the mechanisms associated with liver injury seen in PNALD. This article reviews the recent literature relating to the pathophysiology and treatment of PNALD.

Randomized controlled trial of early parenteral nutrition cycling to prevent cholestasis in very low birth weight infants

OBJECTIVES

To compare the incidence of cholestasis in very low birth weight infants receiving cycled versus continuous parenteral nutrition, and to determine factors that predispose to parenteral nutrition-associated cholestasis (PNAC).

STUDY DESIGN

Preterm infants weighing ≤ 1250 g (n = 70) at birth were randomly assigned within the first 5 postnatal days to either cycle (n = 34) or continuous (n = 36) parenteral nutrition. Liver function tests were obtained at baseline, and sequentially thereafter. Cholestasis was defined as direct bilirubin >2 mg/dL. Infants with major congenital anomalies, congenital hepatic disease, clinically apparent congenital viral infection, and those who required major abdominal surgery were excluded.

RESULTS

The incidence of PNAC was similar in the 2 groups (cycle 32% vs continuous 31%; P = 1.0). Bilirubin and transaminases were similar in both groups by repeated measures of ANOVA. Gestational age, birth weight, and Apgar scores were significantly lower, and Clinical Risk Index for Babies II scores were significantly higher in infants who developed PNAC. Using backward selection logistic regression, bronchopulmonary dysplasia, duration of parenteral nutrition, and days to full enteral nutrition emerged as factors independently associated with PNAC.

CONCLUSIONS

Early prophylactic parenteral nutrition cycling in very low birth weight infants in this study did not reduce cholestasis. Time to full feedings is a significant predictor for PNAC in very low birth weight infants. Preterm infants with bronchopulmonary dysplasia are more likely to have PNAC as a comorbidity. The Clinical Risk Index for Babies II score may help identify those preterm infants who might benefit from future prospective prevention trials.

Implementation of a multidisciplinary team approach and fish oil emulsion administration in the management of infants with short bowel syndrome and parenteral nutrition-associated liver disease

OBJECTIVE

To describe the authors' experience with the implementation of a multidisciplinary approach and use of fish oil emulsion (FOE) in the management of infants with short bowel syndrome (SBS) and parenteral nutrition-associated liver disease (PNALD).

METHODS

Between August 2006 and June 2009, four cases of SBS and severe PNALD were managed by the team using specifically developed protocols. The FOE was initiated if serum direct bilirubin levels were ≥100 µmol/L. To quantify the degree of exposure to high serum direct bilirubin levels over time, the area under the curve (AUC) for each patient was calculated before and after initiation of FOE. Linear regression analyses were performed to evaluate correlations between the AUC, duration of cholestasis and initiation of FOE.

RESULTS

All patients survived and no complications were observed during the study period. After the first patient, FOE was initiated progressively earlier, but poor correlation between the AUC before and after its introduction was observed (r(2)=0.41924). However, there was strong correlation between the duration of PNALD before FOE initiation and time to resolution (r(2)=0.72133): the earlier the FOE was initiated, the shorter the time to resolution.

CONCLUSION

The authors report a positive experience with the implementation of a multidisciplinary approach and the use of FOE in infants with SBS and severe PNALD. The earlier the FOE was initiated during the cholestatic process, the shorter the time to resolution. The present study is a hypothesis generator, raising the question of whether an earlier introduction of this particular therapy can effectively shorten the cholestasis process in these patients.

Outcome on home parenteral nutrition for benign intestinal failure: a review of the literature and benchmarking with the European prospective survey of ESPEN

BACKGROUND & AIMS

Indications and timing for referral for intestinal transplantation (ITx) were investigated through a review of the literature on home parenteral nutrition (HPN) for benign intestinal failure and a benchmarking to the results of a prospective European survey which evaluated the appropriateness of the current indications for ITx.

METHODS

Manuscripts reporting outcomes of adults and children on HPN were retrieved through a PubMed search. Data from the European survey were compared with those on HPN reported in the literature, and with those on ITx reported by the USA registry and by the Pittsburgh center.

RESULTS

HPN is a safe treatment with a high probability of survival. The risk of death during HPN is increased by the absence of a specialist team, and appears greater during the early period of treatment. Survival probability is decreased in patients with: age >40 or <2 years, very short bowel remnant, presence of a stoma, chronic intestinal pseudo-obstruction of myopathic origin, systemic sclerosis, radiation enteritis, intra-abdominal desmoids, necrotizing enterocolitis, congenital mucosal diseases. Liver failure is the HPN-related complication with the greatest risk of death. Death related to venous catheter complications is rare. The benchmarking supported the results of the European survey.

Intravenous fat emulsions reduction for patients with parenteral nutrition-associated liver disease

OBJECTIVE

To test the hypothesis that implementation of a marked reduction in intravenous fat will result in reversal of parenteral nutrition-associated liver disease (PNALD) in infants.

STUDY DESIGN

Prospective study of intravenous fat emulsion reduction in parenteral nutrition to 1 g/kg/d 2 times per week in neonates diagnosed with PNALD. Primary outcome measure was total bilirubin levels compared with gestational age, birth weight, and diagnosis-matched historical controls receiving 3 g/kg/d of intravenous lipids.

RESULTS

Intravenous fat emulsion reduction resulted in a significant decline in total bilirubin levels compared with controls. Comparison of growth in the 2 groups was similar. Mild essential fatty acid deficiency was detected in 8 of 31 infants and was reversed with additional days of lipid infusion. No significant adverse events were noted.

CONCLUSIONS

An association between intravenous lipid emulsion administration and the development of PNALD seems probable. Use of intravenous fat emulsion reduction is a potential approach to reverse PNALD in young infants. Frequent monitoring of essential fatty acid deficiency is needed with the use of this regimen.

Improved outcome in neonatal short bowel syndrome using parenteral fish oil in combination with ω-6/9 lipid emulsions

BACKGROUND

Newborn infants with short bowel syndrome (SBS) represent a high-risk group of developing intestinal failure-associated liver disease (IFALD), which may be fatal. However, infants have a great capacity for intestinal growth and adaptation if IFALD can be prevented or reversed. A major contributing factor to IFALD may be the soybean oil-based intravenous lipid emulsions used since the introduction of parenteral nutrition (PN) 40 years ago.

METHODS

This retrospective study compares the outcome in 20 neonates with SBS treated with parenteral fish oil (Omegaven) in combination with ω-6/9 lipid emulsions (ClinOleic) with the outcome in a historical cohort of 18 patients with SBS who received a soybean oil-based intravenous lipid emulsion (Intralipid).

RESULTS

Median gestational age was 26 weeks in the treatment group and 35.5 weeks in the historical group. All patients were started on PN containing Intralipid that was switched to ClinOleic/Omegaven in the treatment group at a median age of 39 gestational weeks. In the treatment group, direct bilirubin levels were reversed in all 14 survivors with cholestasis (direct bilirubin >50 umol/L). Median time to reversal was 2.9 months. Only 2 patients died of liver failure (10%). In the historical cohort, 6 patients (33%) died of liver failure, and only 2 patients showed normalization of bilirubin levels.

CONCLUSIONS

Parenteral fish oil in combination with ω-6/9 lipid emulsions was associated with improved outcome in premature neonates with SBS. When used instead of traditional soybean-based emulsions, this mixed lipid emulsion may facilitate intestinal adaptation by increasing the IFALD-free period.

A contemporary analysis of parenteral nutrition-associated liver disease in surgical infants

BACKGROUND/PURPOSE

Despite advances in pediatric nutritional support and a renewed focus on management of intestinal failure, there are limited recent data regarding the risk of parenteral nutrition (PN)-associated liver disease in surgical infants. This study investigated the incidence of cholestasis from PN and risk factors for its development in this population.

METHODS

A retrospective review was performed of all neonates in our institution who underwent abdominal surgery and required postoperative PN from 2001 to 2006. Cholestasis was defined as 2 conjugated bilirubin levels greater than 2 mg/dL over 14 days. Nonparametric univariate analyses and multivariate logistic regression were used to model the likelihood of developing cholestasis. Median values with range are presented.

RESULTS

One hundred seventy-six infants met inclusion criteria, and patients received PN for 28 days (range, 2-256 days). The incidence of cholestasis was 24%. Cholestatic infants were born at an earlier gestational age (34 vs 36 weeks; P < .01), required a 3-fold longer PN duration (76 vs 21 days; P < .001), had longer inpatient stays (86 vs 29 days; P < .001), and were more likely to be discharged on PN. The median time to cholestasis was 23 days. Cholestasis was an early development; 77% of cholestatic infants developed cholestasis by 5 weeks of PN exposure. On multivariate regression, only prematurity was significantly associated with development of cholestasis (P < .05).

CONCLUSION

In this analysis, the development of PN-associated liver disease occurred early in the course of exposure to PN. These data help to define the time course and prognosis for PN-associated cholestasis in surgical infants.