Intestinal failure-associated liver disease in surgical infants requiring long-term parenteral nutrition

Quality of Life in Long-Term Survivors of Surgical Necrotizing Enterocolitis

OBJECTIVE

This study evaluated the quality of life (QoL) in patients who have recovered from surgical necrotizing enterocolitis (NEC).

METHODS

This is a cross-sectional study conducted in a tertiary centre and patients who have received surgery for NEC between 2000 and 2014 were invited to participate. The Pediatric Quality of Life Inventory Generic (PedsQL™) Core Scale Version 4.0 was used as the assessment tool. Values were reported as median (interquartile rage) and compared with age-matched controls.

RESULTS

During the study period, 90 patients were eligible for the study and 29 patients have completed the survey. There was no gender difference and the median age was 10 years (9-13 years). Nine patients have suffered from short bowel syndrome (SBS) as a result of the surgery. For the QoL assessment, 17 participants have completed both parent proxy and child-rated survey; 11 completed the parent-rated survey and 1 completed child-rated survey only. The scores for parent-rated survey were - overall: 86.4 (70.7-92.7); physical: 95.3 (83.6-100) and psychosocial: 82.5 (66.3-90.4). The scores for child-rated survey were - overall: 82.1 (73.4-96.2); physical: 96.9 (90.6-99.2) and psychosocial: 81.7 (64.2-95.8). Regarding the impact of previous SBS on the QoL, there were no significant difference in the overall score for both parent proxy and child-rated survey (SBS-ve vs + ve) (parent-rated: 87.5 vs 85.3, p = 0.849; child-rated: 81.0 vs 88.0, p = 0.503). There were also no differences in physical and psychosocial assessments (parent-rated: [physical] 95.3 vs 95.3, p = 0.267; [psychosocial] 84.2 vs 80.0, p = 0.274; child-rated: [physical] 95.3 vs 96.9, p = 0.395; [psychosocial] 79.2 vs 87.5, p = 0.611).

CONCLUSION

The QoL in long-term survivors of surgical NEC without major medical illnesses is comparable to normal population. However, they may have a lower psychosocial well-being that should be addressed. Previous history of SBS does not have a significant impact on the future QoL.

LEVEL OF EVIDENCE

III.

An Overview of Parenteral Nutrition from Birth to Adolescence Based on a Composite Fish Oil Containing Lipid Emulsion and a Pediatric Amino Acid Solution

Intestinal failure (IF) is characterized by a critical reduction in functional gut mass below the minimum needed for optimal growth in children. It requires parenteral nutrition (PN) and home-PN (HPN), which is challenging in terms of meeting nutritional needs according to age, growth velocity, clinical situation, and rapid changes in fluid and electrolyte requirements. Due to these complex requirements, age-adapted multi-chamber bags (MCBs) are important additions to the nutrition armamentarium. The launch of composite fish oil (FO)-containing intravenous lipid emulsions (ILEs) heralded the development of MCBs containing these ILEs in combination with a crystalline amino acid solution adapted for pediatric use. The safety and efficacy of lipid and amino acid components in this context have been widely documented in numerous published studies. This narrative manuscript includes a review of the articles published in PudMed, Embase, and Google Scholar up to June 2023 for the age groups of term infants to children and adolescents. Preterm infants with their highly specific demands are not included. It aims to offer an overview of the clinical experience regarding the use of a composite FO-based ILE and a developed specific amino acid solution.

Intestinal Knockout of Peroxisome Proliferator-Activated Receptor-Alpha Affects Structural Adaptation but not Liver Injury Following Massive Enterectomy

BACKGROUND

Resection-associated liver steatosis, injury, and fibrosis is a devastating complication associated with massive small bowel resection (SBR). Peroxisome proliferator-activated receptor-alpha (PPARα) is a key regulator of intestinal lipid transport and metabolism whose expression is selectively increased after SBR. Here we asked if attenuating intestinal PPARα signaling would prevent steatosis and liver injury after SBR.

METHODS

Pparα was deleted selectively in adult mouse intestine using a tamoxifen-inducible Cre-LoxP breeding schema. Mice underwent 50% SBR. At 10 weeks post-operatively, metabolic phenotyping, body composition analysis, in vivo assessment of lipid absorption and intestinal permeability, and assessment of adaptation and liver injury was completed.

RESULTS

Pparα intestinal knockout and littermate control mice were phenotypically similar in terms of weight trends and body composition after SBR. All mice demonstrated intestinal adaptation with increased villus height and crypt depth; however, Pparα intestinal knockout mice exhibited decreased villus growth at 10 weeks compared to littermate controls. Liver injury and fibrosis were similar between groups as assessed by serum AST and ALT levels, Sirius Red staining, and hepatic expression of Col1a1 and Acta2.

CONCLUSIONS

Inducible intestinal deletion of Pparα influences structural adaptation but does not mitigate liver injury after SBR. These findings suggest that enterocyte PPARα signaling in adult mice is dispensable for resection-induced liver injury. The results are critical for understanding the contribution of intestinal lipid metabolic signaling pathways to the pathogenesis of hepatic injury associated with short bowel syndrome.

Intestinal twin-to-twin transplant for short gut: Review of the literature and discussion of a complex case

Paediatric Intestinal Transplantation (IT) presents the highest mortality on the waiting-list due to anatomical disproportion. Living-Donor IT (LDIT) offers the best advantages and when performed among identical monozygotic twins, it also benefits from unique immunology. According to MEDLINE/Pubmed, twin-to-twin LDIT has been performed in seven cases (6:7 males, median age of 32 years). None of the patients received immunosuppression postoperatively. Only one paediatric twinto- twin LDIT was carried out with a 160-cm mid-ileum tract: an interposed 4/5-cm arterial graft was required to ensure a tensionfree anastomosis to the anterior wall of the infra-renal abdominal aorta. In contrast, venous anastomosis was done directly to the inferior cava vein. We present a case for debate of a 13- month-old SBS patient where a twin-LDIT was discussed with parents, who decided to wait after careful analysis and ethical considerations.

A novel maladaptive unfolded protein response as a mechanism for small bowel resection-induced liver injury

The unfolded protein response (UPR) is a complex adaptive signaling pathway activated by the accumulation of misfolded proteins in the endoplasmic reticulum (ER). ER stress (ERS) triggers a cascade of responses that converge upon C/EBP homologous protein (CHOP) to drive inflammation and apoptosis. Herein, we sought to determine whether liver injury and fibrosis after small bowel resection (SBR) were mediated by a maladaptive hepatic ERS/UPR. C57BL/6 mice underwent 50% proximal SBR or sham operation. Markers of liver injury and UPR/ERS pathways were analyzed. These were compared with experimental groups including dietary fat manipulation, tauroursodeoxycholic acid (TUDCA) treatment, distal SBR, and global CHOP knockout (KO). At 10 wk, proximal SBR had elevated alanine aminotransferase/aspartate aminotransferase (ALT/AST) (P < 0.005) and greater hepatic tumor necrosis factor-α (TNFα) (P = 0.001) and collagen type 1 α1 (COL1A1) (P = 0.02) than shams. SBR livers had increased CHOP and p-eIF2α, but were absent in activating transcription factor 4 (ATF4) protein expression. Low-fat diet (LFD), TUDCA, and distal SBR groups had decreased liver enzymes, inflammation, and fibrosis (P < 0.05). Importantly, they demonstrated reversal of hepatic UPR with diminished CHOP and robust ATF4 signal. CHOP KO-SBR had decreased ALT but not AST compared with wild-type (WT)-SBR (P = 0.01, P = 0.12). There were no differences in TNFα and COL1A1 (P = 0.09, P = 0.50). SBR-induced liver injury, fibrosis is associated with a novel hepatic UPR/ERS response characterized by increased CHOP and decreased ATF4. LFD, TUDCA, and ileocecal resection rescued the hepatic phenotype and reversed the UPR pattern. Global CHOP KO only partially attenuated liver injury. This underscores the significance of disruptions to the gut/liver axis after SBR and potentiates targets to mitigate the progression of intestinal failure-associated liver disease.NEW & NOTEWORTHY The unfolded protein response (UPR) is a complex signaling cascade that converges upon C/EBP-homologous protein (CHOP). Under conditions of chronic cellular stress, the UPR shifts from homeostatic to proapoptotic leading to inflammation and cell death. Here, we provide evidence that small bowel resection-induced liver injury and fibrosis are mediated by a maladaptive hepatic UPR. Low-fat diet, TUDCA treatment, and ileocecal resection rescued the hepatic phenotype and reversed the UPR pattern.

Intestinal Continuity Alleviates Pediatric Intestinal Failure-Associated Liver Disease

Background

Type I short bowel syndrome (SBS) occurs after a critical reduction in the functional gut mass and resection of intestinal continuity after ileostomy or jejunostomy for necrotizing enterocolitis (NEC), intestinal atresia or other causes. SBS is often accompanied with intestinal failure-associated liver disease (IFALD) who requires long-term parenteral nutrition (PN). Our study aimed to observe the effect of intestinal continuity on the hepatic function of pediatric intestinal failure (IF) patients with type I SBS.

Methods

The pre-and post-anastomosis medical records of 35 pediatric patients with type I SBS from April 2013 to April 2019 were reviewed retrospectively. The average growth (cm/month) in the proximal and distal small bowel lengths was calculated as the growth in intestinal length (cm)/the duration (month) from enterostomy to anastomosis. The changes in hepatic function from enterostomy to anastomosis were evaluated by assessment of hepatic function before anastomosis for 6 weeks and after anastomosis for 4 weeks.

Results

The average growth in proximal intestinal length was 9.3 cm/month (±7.2) in neonates and 2.8 cm/month (1.3, 11.9) in infants and children, and in distal intestinal length was 1.5 cm/month (0, 2.7) in neonates and 0.4 cm/month (0, 1.4) in infants and children. The incidence of IFALD was 28.6% 1 month before anastomosis and 20.0% 1 month after anastomosis (p < 0.05).

Conclusion

In pediatric type I SBS with IFALD, restoration of intestinal continuity may alleviate liver injury. There was an intestinal compensatory effect on the growth in the intestinal length after resection, and better results were seen in neonates in terms of intestinal length growth.

Current Surgical Concepts and Indications in the Management of the Short Bowel State: A Call for the Use of Multidisciplinary Intestinal Rehabilitation Programs

The mainstay of management for short bowel syndrome (SBS) is to promote access to the best quality of care provided by the intestinal rehabilitation program (IRP) in specialized centres. When treating SBS patients, the main goal is to minimize disease-associated complications, as well as achieve enteral autonomy. Surgical strategies should be selected cautiously upon the actual state of the bowel with respect to what it is clinically relevant for that specific patient. To this aim, a personalized and multidisciplinary approach for such a complex syndrome is needed.

Liver injury after small bowel resection is prevented in obesity-resistant 129S1/SvImJ mice

Intestinal failure-associated liver disease is a major morbidity associated with short bowel syndrome. We sought to determine if the obesity-resistant mouse strain (129S1/SvImJ) conferred protection from liver injury after small bowel resection (SBR). Using a parenteral nutrition-independent model of resection-associated liver injury, C57BL/6J and 129S1/SvImJ mice underwent a 50% proximal SBR or sham operation. At postoperative week 10, hepatic steatosis, fibrosis, and cholestasis were assessed. Hepatic and systemic inflammatory pathways were evaluated using oxidative markers and abundance of tissue macrophages. Potential mechanisms of endotoxin resistance were also explored. Serum lipid levels were elevated in all mouse lines. Hepatic triglyceride levels were no different between mouse strains, but there was an increased accumulation of free fatty acids in the C57BL/6J mice. Histological and serum markers of hepatic fibrosis, steatosis, and cholestasis were significantly elevated in resected C57BL/6J SBR mice as well as oxidative stress markers and macrophage recruitment in both the liver and visceral white fat in C57BL/6J mice compared with sham controls and the 129S1/SvImJ mouse line. Serum endotoxin levels were significantly elevated in C57BL/6J mice with significant elevation of hepatic TLR4 and reduction in PPARα expression levels. Despite high levels of serum lipids, 129S1/SvImJ mice did not develop liver inflammation, fibrosis, or cholestasis after SBR, unlike C57BL/6J mice. These data suggest that the accumulation of hepatic free fatty acids as well as increased endotoxin-driven inflammatory pathways through PPARα and TLR4 contribute to the liver injury seen in C57BL/6J mice with short bowel syndrome.NEW & NOTEWORTHY Unlike C57BL/6 mice, the 129S1/SvImJ strain is resistant to liver inflammation and injury after small bowel resection. These disparate outcomes are likely due to the accumulation of hepatic free fatty acids as well as increased endotoxin-driven inflammatory pathways through PPARα and TLR4 in C57BL/6 mice with short bowel syndrome.

The prevalence of liver fibrosis according to non-invasive tools in a pediatric home parenteral nutrition cohort

BACKGROUND & AIMS

Liver biopsy is no viable tool to routinely screen for liver fibrosis in children suffering from chronic intestinal failure (IF). We aim to assess the prevalence of liver fibrosis in a cohort of children with chronic IF by non-invasive tests: transient elastography (TE), aspartate-aminotransferase-to-platelet-ratio-index (APRI) and enhanced liver fibrosis (ELF) score.

METHODS

Cross sectional study where patients with chronic IF, receiving parenteral nutrition (PN) for at least 3 months, were enrolled. TE, APRI and ELF score were measured. Using Spearman's rank correlation coefficient and Kruskal-Wallis H test, the correlation between TE, APRI, ELF score and known risk factors for development of intestinal failure-associated liver disease (IFALD) were calculated.

RESULTS

32 patients were included (50% female), median age was 8 years and 4 months, median PN duration was 45 months. Six patients (21%) had TE ≥6.5 kPa, indicating significant fibrosis. Twelve patients (38%) had APRI ≥.5, indicating fibrosis. ELF score indicated moderate fibrosis in 17 patients (63%) and significant fibrosis in 10 patients (37%). TE and APRI correlated significantly with known risk factors for IFALD, but ELF showed poor correlation with known risk factors for IFALD.

CONCLUSION

In a cohort of pediatric patients suffering from chronic IF, TE measurement, APRI and ELF test show a varying, but substantial proportion of subjects with fibrosis. The diagnostic value of these tests and their role in the management of pediatric IF must be determined in larger cohorts with liver biopsy as reference standard.

TRIAL REGISTRATION

Academic Medical Center medical ethics committee number: METC 2017_185.

Effects of high-fat diet on liver injury after small bowel resection

BACKGROUND

The optimal regimen for enteral nutritional support in the management of children with short bowel syndrome (SBS) is not well characterized. A high fat, enteral diet is theoretically beneficial due to increased caloric density and enhanced structural adaptation. We therefore sought to determine the long-term effects of a high fat diet (HFD) on liver injury, a common complication of SBS, compared to a standard chow (SC) diet.

METHODS

Using a parenteral nutrition-independent model of resection-associated liver injury, C57BL/6 mice underwent a sham operation or a 50% or 75% proximal small bowel resection (SBR). Mice in each group were then fed either a HFD (35% kcal fat) or SC (13% kcal fat). At post-operative week 15, markers of liver injury were quantified.

RESULTS

Liver triglyceride levels were increased from 7- to 19-fold in mice on the HFD compared to mice fed SC in the sham, 50%, and 75% resection groups. Serum ALT (2.2-fold increase in 75% resected mice compared to sham controls) and AST (2.0- and 2.7-fold increases in 50% and 75% resected mice, respectively) levels as well as fibrotic liver staining were elevated only in resected mice fed a HFD.

CONCLUSION

Long-term enteral feeding of HFD in our murine SBS model is associated with hepatic steatosis and liver injury. Our observation that liver steatosis and injury occur independent of parenteral nutrition suggests that enteral feeding composition and magnitude of intestinal loss may make a significant contribution to intestinal failure-associated liver disease.

Intestinal failure-associated liver disease (IFALD): insights into pathogenesis and advances in management

Premature infants and children with intestinal failure (IF) or short bowel syndrome are susceptible to intestinal failure-associated liver disease (IFALD, previously referred to as parenteral nutrition-associated liver disease, or PNALD). IFALD in children is characterized by progressive cholestasis and biliary fibrosis, and steatohepatitis in adults, and is seen in individuals dependent upon prolonged administration of PN. Many factors have been proposed as contributing to the pathogenesis of IFALD. In recent years, the focus has been on the potential synergistic roles of the intestinal microbiome, increased intestinal permeability, activation of hepatic innate immune pathways, and the use of intravenous soybean-oil-based intravenous lipid emulsions (SO-ILE). In vitro and in vivo studies have identified stigmasterol, a component of the plant sterols present in SO-ILE, as playing an important role. Although various strategies have been adopted to prevent or reverse IFALD, most suffer from a lack of strong evidence supported by well-designed, prospective clinical trials with clearly defined endpoints. Reduction in the amount of SO-ILEs or replacement with non-SO-ILEs has been shown to reverse IFALD although safety and long-term effectiveness have not been studied. Medical and surgical modalities to increase intestinal adaptation, advance enteral feedings, and prevent central line bloodstream infections are also important preventative strategies. There is a continued need to conduct high-quality, prospective trials with clearly define outcome measures to ascertain the potential benefits of these strategies.

The Effect of Glutamine Supplementation on Microbial Invasion in Surgical Infants Requiring Parenteral Nutrition: Results of a Randomized Controlled Trial

BACKGROUND

To determine whether parenteral plus enteral glutamine supplementation influences microbial invasion in surgical infants who require parenteral nutrition (PN).

METHODS

An prospective double-blind randomized controlled trial studying surgical infants receiving PN for at least 5 days for congenital or acquired intestinal anomalies (2009-2012) was used. Infants were randomized to receive either glutamine supplementation (parenteral plus enteral; total 400 mg/kg/d) or isonitrogenous control. The primary end point was microbial invasion evaluated after 5 days of supplementation and defined as: (i) positive conventional blood culture, (ii) evidence of microbial DNA in blood (polymerase chain reaction), (iii) plasma endotoxin level ≥50 pg/mL, or (iv) plasma level of lipopolysaccharide binding protein ≥50 ng/mL. Data are given as median (range) and compared by logistic regression.

RESULTS

Sixty infants were randomized and reached the primary end point. Twenty-five patients had intestinal obstruction, 19 had abdominal wall defects, and 13 had necrotizing enterocolitis. Thirty-six infants showed evidence of microbial invasion during the study, and 17 of these were not detected by conventional blood culture. There was no significant difference between the 2 groups in the primary outcome; evidence of microbial invasion after 5 days was found in 9/31 (control group) and 8/29 (glutamine group) (odds ratio 0.83 [0.24-2.86; P = 0.77]).

CONCLUSION

More than half of surgical infants requiring PN showed evidence of microbial invasion. Approximately half of this was not detectable by conventional blood cultures. Parenteral plus enteral glutamine supplementation had no effect on incidence of microbial invasion.

An Observational Study of Smoflipid vs Intralipid on the Evolution of Intestinal Failure-Associated Liver Disease in Infants With Intestinal Failure

BACKGROUND

SMOFlipid has a more diverse lipid profile than traditional Intralipid and has become the standard lipid for patients in our intestinal rehabilitation program. Our objective was to compare outcomes in neonates with intestinal failure (IF) who received SMOFlipid against those receiving Intralipid.

METHODS

This was a retrospective cohort study of infants with IF with a minimum follow-up of 12 months in 2008-2016. Patients were stratified into 2 groups: group 1 received SMOFlipid; group 2 was a historical cohort who received Intralipid. The primary outcome was liver function evaluated using conjugated bilirubin (CB) levels. Statistical analysis included the Mann-Whitney U and χ² tests, with an α value < 0.05 considered significant. Approval was obtained from our institutional review board.

RESULTS

Thirty-seven patients were evaluated (17 = SMOFlipid, 20 = Intralipid). SMOFlipid patients were less likely to reach CB of 34 (24% vs 55%, P = 0.05), 50 µmol/L (11.8% vs 45%; P = 0.028), and did not require Omegaven (0% vs 30%; P = 0.014). CB level at 3 months after initiation of parenteral nutrition (PN) was lower in patients receiving SMOFlipid (0 vs 36 µmol/L; P = 0.01). Weight z-scores were improved for patients receiving SMOFlipid at 3 months (-0.932 vs -2.092; P = 0.028) and 6 months (-0.633 vs -1.614; P = 0.018). There were no differences in PN-supported patients or demographics between the groups.

CONCLUSION

Use of SMOFlipid resulted in decreased development of IF-associated liver disease in patients with IF when assessed using biochemical tests.

Ultrasound Elastography as a Non-Invasive Method to Monitor Liver Disease in Children with Short Bowel Syndrome: Updated Results

PURPOSE

The purpose of the study was to determine the accuracy of acoustic radiation force impulse (ARFI) ultrasound elastography in assessing the degree of liver disease in children with short bowel syndrome (SBS).

METHODS

A prospective observational cohort study of patients with SBS who underwent a liver biopsy and ARFI elastography was performed. Mean shear wave speed (SWS) and stage of fibrosis was evaluated using t-tests. Receiver operating characteristic curves (ROC) were generated and the area under the curves (AUC) estimated in order to assess the accuracy of SWS measurements to discriminate between stages of fibrosis.

RESULTS

Thirty-seven paired elastography and biopsy samples from 31 patients were included. The median age was 0.6 years, and 61% were male. There was a significant positive correlation between stage of fibrosis and mean SWS (β=0.16 m/s increase per stage, p=<0.001). ROC analysis revealed that mean SWS had good accuracy for discriminating between mild liver fibrosis (F0-F1) and moderate to severe fibrosis (F2-F4) (AUC=0.80, 95% CI 0.65-0.95). In addition, ROC analysis demonstrated that mean SWS can also accurately discriminate between mild to moderate fibrosis (F0-F2) and more severe fibrosis (F3-F4) (AUC=0.84, 95% CI 0.71-0.96).

CONCLUSION

ARFI elastography is an accurate, non-invasive method to monitor liver disease in children with SBS.

TYPE OF STUDY

Retrospective Cohort Study LEVEL OF EVIDENCE: II.

Lymphatic network remodeling after small bowel resection

BACKGROUND

Short gut syndrome (SGS) following massive small bowel resection (SBR) is a major cause of pediatric mortality and morbidity secondary to nutritional deficiencies and the sequelae of chronic total parenteral nutrition use, including liver steatosis. Despite the importance of lymphatic vasculature in fat absorption, lymphatic response after SBR has not been studied. We hypothesize that lymphatic vessel integrity is compromised in SGS, potentially contributing to the development of impaired lipid transport leading to liver steatosis and metabolic disease.

METHODS

Mice underwent 50% proximal SBR or sham operations. Imaging of lymphatic vasculature in the lamina propria and mesentery was compared between sham and SBR Prox1 ERCre-Rosa26^LSLTdTomato mice. mRNA expression levels of lymphangiogenic markers were performed in C57BL/6J mice.

RESULTS

Lymphatic vasculature was significantly altered after SBR. Mesenteric lymphatic collecting vessels developed new branching structures and lacked normal valves at branch points, while total mucosal lymphatic capillary area in the distal ileum decreased compared to both sham and intraoperative controls. Intestinal Vegfr3 expression also increased significantly in resected mice.

CONCLUSIONS

Intestinal lymphatics, in both the lamina propria and mesentery, dramatically remodel following SBR. This remodeling may affect lymphatic flow and function, potentially contributing to morbidities and nutritional deficiencies associated with SGS.

Gastrointestinal sequelae after surgery for necrotising enterocolitis: a systematic review and meta-analysis

OBJECTIVES

To document what types of gastrointestinal sequelae were described after surgery for necrotising enterocolitis (NEC) and to analyse their frequency.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, EMBASE and the Cochrane library (CENTRAL) from 1990 to October 2016.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included studies, which provided original data on the occurrence of gastrointestinal sequelae in patients surviving surgery for NEC. Meta-analysis and metaregression to assess heterogeneity were performed for studies including 10 or more patients with gastrointestinal strictures, recurrence of NEC, intestinal failure (IF) and adhesion ileus.

RESULTS

Altogether 58 studies, including 4260 patients, met the inclusion criteria. Strictures were reported to occur in 24% (95% CI 17% to 31%) of surviving patients, recurrence of NEC in 8% (95% CI 3% to 15%), IF in 13% (95% CI 7% to 19%) and adhesion ileus in 6% (95% CI 4% to 9%). Strictures were more common following enterostomy (30%; 95% CI 23% to 37%) than after primary anastomosis (8%; 95% CI 0% to 23%) and occurred more often after enterostomy without bowel resection than with bowel resection. We found considerable heterogeneity in the weighted average frequency of all sequelae (I² range: 38%-90%). Intestinal outcomes were poorly defined, there were important differences in study populations and designs, and the reported findings bear a substantial risk of bias.

CONCLUSIONS

Gastrointestinal sequelae in neonates surviving surgery for NEC are frequent. Long-term follow-up assessing defined gastrointestinal outcomes is warranted.

Probiotic research in neonates with congenital gastrointestinal surgical conditions - Now is the time

Neonates with congenital gastrointestinal surgical conditions (CGISC) receive parenteral nutrition, get exposed to multiple courses of antibiotics, undergo invasive procedures, and are nursed in intensive care units. They do not receive early enteral feeding and have limited opportunities for skin to skin contact with their mothers. Many of these infants receive gastric acid suppression therapies. All these factors increase the risk of gut dysbiosis in these infants. Gut dysbiosis is known to be associated with increased risk of infections and other morbidities in ICU patients. Experimental studies have shown that probiotics inhibit gut colonization with pathogenic bacteria, enhance gut barrier function, facilitate colonization with healthy commensals, protect from enteropathogenic infection through production of acetate, reduce antimicrobial resistance, enhance innate immunity, and increase the maturation of the enteric nervous system and promote gut peristalsis. Through these mechanisms, probiotics have the potential to decrease the risk of sepsis and inflammation, improve feed tolerance and minimise cholestasis in neonates with CGISC. Among preterm non-surgical infants, evidence from more than 35 RCTs and multiple observational studies have shown probiotics to be safe and beneficial. A RCT in neonates (N=24) with gastroschisis found that probiotic supplementation partially attenuated gut dysbiosis. Two ongoing RCTs (total N=168) in neonates with gastrointestinal surgical conditions are expected to provide feasibility data to enable the conduct of large RCTs. Rigorous quality assurance of the probiotic product, ongoing microbial surveillance and clinical vigilance are warranted while conducting such RCTs.

One-year outcomes following surgery for necrotising enterocolitis: a UK-wide cohort study

OBJECTIVE

The objective was to describe outcomes and investigate factors affecting prognosis at 1 year post intervention for infants with surgical necrotising enterocolitis (NEC).

DESIGN

Using the British Association of Paediatric Surgeons Congenital Anomalies Surveillance System, we conducted a prospective, multicentre cohort study of every infant reported to require surgical intervention for NEC in the UK and Ireland between 1 March 2013 and 28 February 2014. Association of independent variables with 1-year mortality was investigated using multivariable logistic regression analysis.

SETTING

All 28 paediatric surgical centres in the UK and Ireland.

PATIENTS

Infants were eligible for inclusion if they were diagnosed with NEC and deemed to require surgical intervention, regardless of whether that intervention was delivered.

OUTCOMES

Primary outcome was mortality within 1 year of the decision to intervene surgically.

RESULTS

236 infants were included in the study. 208 (88%) infants had 1-year follow-up. 59 of the 203 infants with known survival status (29%, 95% CI 23% to 36%) died within 1 year of the decision to intervene surgically. Following adjustment, key factors associated with reduced 1-year mortality included older gestational age at birth (adjusted OR (aOR) 0.87, 95% CI 0.78 to 0.96). Being small for gestational age (SGA) (aOR 3.6, 95% CI 1.4 to 9.5) and requiring parenteral nutrition at 28 days post-decision to intervene surgically (aOR 3.5, 95% CI 1.1 to 11.03) were associated with increased 1-year mortality.

CONCLUSIONS

Parents of infants undergoing surgery for NEC should be counselled that there is approximately a 1:3 risk of death in the first post-operative year but that the risk is lower for infants who are of greater gestational age at birth, who are not SGA and who do not require parenteral nutrition at 28 days post-intervention.

Pediatric intestinal failure-associated liver disease

PURPOSE OF REVIEW

The goal of this review is to provide updates on the definition, pathophysiology, treatment, and prevention of intestinal failure-associated liver disease (IFALD) that are relevant to care of pediatric patients.

RECENT FINDINGS

Current literature emphasizes the multifactorial nature of IFALD. The pathogenesis is still largely unknown; however, molecular pathways have been identified. Key to these pathways are proinflammatory cytokines involved in hepatic inflammation and bile acids synthesis such as Toll-like receptor 4 and farnesoid X receptor, respectively. Research for prevention and treatment is aimed at alleviating risk factors associated with IFALD, principally those associated with parental nutrition. Multiple nutrients and amino acids are relevant to the development of IFALD, but lipid composition has been the primary focus. Lipid emulsions with a lower ratio of omega-6-to-omega-3 polyunsaturated fatty acids (FAs) appear to improve bile flow and decrease intrahepatic inflammation. Long-term consequences of these alternative lipid emulsions are yet to be determined.

SUMMARY

IFALD remains the greatest contributor of mortality in patients with intestinal failure. Many factors contribute to its development, namely, alterations in the gut microbiome, sepsis, and lack of enteral intake. Novel combinations of lipid formulations are promising alternatives to purely soy-based formulas to reduce cholestasis.

Total Parenteral Nutrition-Induced Cholestasis: Prevention and Management

When cholestasis occurs in patients receiving total parenteral nutrition, it is the result of many pathogenic pathways converging on the hepatic acinus. The result may be a temporary rise in liver function tests. The resulting fibrosis, portal hypertension, and jaundice are hallmarks of type 3 intestinal-associated liver disease to which children are more susceptible than adults. The key to prevention is in identifying high-risk scenarios, meticulous monitoring, and personalized prescription of parenteral nutrition solutions combined with an active approach in reducing the impact of inflammatory events when they occur by prompt use of antibiotics and line locks.

Lipid emulsions in the treatment and prevention of parenteral nutrition-associated liver disease in infants and children

Long-term parenteral nutrition (PN) carries the risk of progressive liver disease in infants with intestinal failure. Although PN-associated liver disease (PNALD) is multifactorial in etiology, components of soybean oil lipid emulsions have been implicated in the disease's pathogenesis. Historically, infants with PNALD who were unable to wean from PN to full enteral feeding developed cirrhosis and end-stage liver disease, which require liver transplantation to survive. Over the past 2 decades, novel strategies for the management of parenteral lipids have improved morbidity and mortality from PNALD in infants with intestinal failure. Current strategies for the treatment of PNALD include restricting the dose of parenteral soybean oil lipid emulsion and/or replacing the soybean oil with a parenteral fish-oil lipid emulsion or emulsions of mixed-lipid sources. The purpose of this report is to review published data that evaluate these strategies in parenteral lipid management for the treatment and prevention of PNALD.

Breast milk is better than formula milk in preventing parenteral nutrition-associated liver disease in infants receiving prolonged parenteral nutrition

BACKGROUND AND AIM

Breast milk has been shown to be associated with greater success with regard to weaning children with intestinal failure off parenteral nutrition (PN). There are only a few studies investigating the role of breast milk in decreasing PN-associated liver disease (PNALD). The aim of our study was to determine whether breast milk is better than formula milk in preventing PNALD in infants receiving PN for >4 weeks.

METHODS

We conducted a retrospective analysis of newborns requiring prolonged parenteral nutrition. We divided the sample into 3 different groups (exclusive breast-feeding, exclusive formula-feeding, and mixed feeding. We compared baseline characteristics, feeding profiles and liver function tests, and liver enzymes among the 3 groups.

RESULTS

Among infants receiving PN for >4 weeks, we found that infants who were fed only breast milk were significantly less likely to develop PNALD (34.6%) compared with those who were fed only formula milk (72.7%; P = 0.008). The mean maximum conjugated bilirubin (P = 0.03) and the mean maximum aspartate aminotransferase were significantly lower in the breast-fed group (P = 0.04) compared with the formula-fed group. Among the mixed-feeding group, infants who received a higher percentage of breast milk showed a significant negative correlation with the mean maximum conjugated bilirubin. (Pearson correlation -0.517, P = 0.027). The mean number of days receiving PN and the average daily lipid intake in the 2 groups was not significantly different.

CONCLUSIONS

As a modality for early enteral nutrition, breast milk is protective against the development of PNALD in infants receiving PN for >4 weeks.

Fish oil-based lipid emulsion in the treatment of parenteral nutrition-associated liver disease

PURPOSE OF REVIEW

Parenteral nutrition-associated liver disease (PNALD) is a major cause of morbidity and mortality in the parenteral nutrition-dependent population. Here, we review the most recent literature involving a fish oil-based lipid emulsion (FOLE) and its effects on PNALD.

RECENT FINDINGS

Vegetable oil-based lipid emulsions (VBLEs) contribute to PNALD. This may be due to parenteral phytosterols and/or the presence of pro-inflammatory mediators. Whereas a small reduction in the dose of VBLE does not appear to prevent PNALD, a significant reduction in the dose may reverse PNALD; however, it carries the risk of essential fatty acid deficiency. Furthermore, the impact of extreme lipid restriction on subsequent neurodevelopment is unknown. Combination lipid emulsions containing fish oil are associated with decreased bilirubin levels, though no studies compare these emulsions with the outcomes with FOLE alone. The utility of FOLE in the reversal of PNALD has been demonstrated and its administration does not lead to essential fatty acid deficiency. Furthermore, there is evidence that FOLE may prevent PNALD.

CONCLUSION

FOLE appears to be an efficacious treatment to reverse PNALD. However, more studies are necessary to determine if FOLE might also be beneficial in the prevention of PNALD. Future studies should additionally focus on the preterm infant population, as they represent a major population requiring parenteral nutrition support for survival.

The effect of lipid restriction on the prevention of parenteral nutrition-associated cholestasis in surgical infants

PURPOSE

Surgical infants requiring long-term parenteral nutrition (PN) are at risk for parenteral nutrition-associated liver disease (PNALD). The purpose of this study was to determine the effect of a lipid restricted PN regimen in preventing the development of PNALD in surgical infants.

METHODS

In 2009, we implemented a lipid restricted strategy in surgical infants expected to be on long-term PN using a soy-based lipid emulsion at a goal provision of 1g/kg/day throughout a patient's entire PN course. An experimental cohort of surgical infants treated with lipid restriction from 2009 to 2011 (n=82) was retrospectively compared to a control cohort of infants from 2005 to 2008 receiving standard intravenous lipid dosing (n=132). A multivariable relative risk regression model was constructed analyzing the association between lipid restriction and PNALD.

RESULTS

Patients admitted during the lipid restriction era had reduced daily lipid provisions compared to the control group (p<0.001). There were no significant differences in demographic or measured clinical characteristics between the two groups. A significant reduction in the incidence of PNALD was demonstrated in the lipid restricted group compared to the control group (22% vs. 43%, p=0.002). On multivariable relative risk regression, patients treated with standard lipid provisions were 1.77 times more likely to develop PNALD than patients who were lipid restricted (95% CI: 1.2-2.7; p=0.007).

CONCLUSION

Restriction of intravenous soy-based lipid in PN-fed surgical infants is associated with a reduction in the incidence of liver disease. Early lipid restriction should be considered in all surgical infants who require PN as a preventative measure against PNALD.

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.