Exploring the complexities of megacystis-microcolon-intestinal hypoperistalsis syndrome: insights from genetic studies

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is an uncommon genetic disorder inherited in an autosomal recessive pattern that affects the muscles that line the bladder and intestines. The most common genes associated with MMIHS mutations are ACTG2, LMOD1, MYH11, MYL9, MYLK, and PDCL3. However, the complete genetic landscape of MMIHS still needs to be fully understood. The diagnosis of MMIHS can be challenging. However, advances in prenatal and diagnostic techniques, such as ultrasound and fetal urine analysis, have improved the ability to detect the syndrome early. Targeted next-generation sequencing (NGS) and other diagnostic tests can also diagnose MMIHS. The management of MMIHS involves addressing severe intestinal dysmotility, which often necessitates total parenteral nutrition (TPN), which can lead to complications such as hepatotoxicity and nutritional deficiencies. Multivisceral and intestinal transplantation has emerged as therapeutic options, offering the potential for improved outcomes and enteral autonomy. Understanding the genetic underpinnings of MMIHS is crucial for personalized care. While the prognosis varies, timely interventions and careful monitoring enhance patient outcomes. Genetic studies have given us valuable insights into the molecular mechanisms of MMIHS. These studies have identified mutations in genes involved in the development and function of smooth muscle cells. They have also shown that MMIHS is associated with defects in the signaling pathways that control muscle contraction. Continued research in the genetics of MMIHS holds promise for unraveling the complexities of MMIHS and improving the lives of affected individuals.

Sepsis and bronchopulmonary dysplasia as potential risk factors for parenteral nutrition-associated cholestasis in neonates: a meta-analysis of retrospective studies

INTRODUCTION

The aim of this study was to evaluate whether sepsis and bronchopulmonary dysplasia (BPD) are risk factors for parenteral nutrition-associated cholestasis (PNAC) and to provide suggestions for the prevention of PNAC in infants.

EVIDENCE ACQUISITION

Electronic databases (PubMed, EBSCO, Elsevier, Springer, Wiley, and Cochrane) were searched for studies published up to October 22, 2017. Associations between sepsis, BPD and PNAC were assessed using odds ratios (ORs) and 95% confidence intervals (CIs). Heterogeneity was assessed using the I2 statistic, and subgroup analyses were performed.

EVIDENCE SYNTHESIS

Nine studies incorporating a total of 2248 cases were included in the meta-analysis. Sepsis was significantly associated with PNAC (pooled OR=2.04; 95% CI: 1.23-2.85), but BPD was not (pooled OR=1.22; 95% CI: 0.65-1.78). In a subgroup analysis, BPD was not associated with PNAC in either the non-Asian group (pooled OR=1.38; 95% CI: 0.58-2.18) or the Asian group (pooled OR=1.05; 95% CI: 0.26-1.84).

CONCLUSIONS

Sepsis, but not BPD, was a risk factor for PNAC in this meta-analysis. Further studies are needed to confirm the findings.

n-3 Polyunsaturated Fatty Acid Supplementation Affects Oxidative Stress Marker Levels in Patients with Type II Intestinal Failure: A Randomized Double Blind Trial

Type II intestinal failure (IF-II) is a condition in which the gastrointestinal tract is compromised. Liver complications may occur because of the pathology and/or prolonged use of parenteral nutrition (PN); oxidative stress has been implicated as one of the causes. Lipid emulsions containing n-3 polyunsaturated fatty acids (PUFAs) have been proposed for the treatment. We aimed to evaluate the effect of 7-day n-3 PUFA supplementation on oxidative stress in IF-II patients receiving PN. This was a randomized, controlled, double-blinded, pilot trial of adult patients with IF-II, receiving either conventional PN (control) or PN enriched with n-3 PUFAs (intervention). Twenty patients were included (14 men, 49 ± 16.9 years), with the ANCOVA analysis the glucose (p = 0.003), and direct bilirubin (p = 0.001) levels reduced; whereas the high-density lipoprotein cholesterol (HDL-C) increased (p = 0.017). In the random-effect linear regression analysis, a reduction (p < 0.0001) in the malondialdehyde (MDA) level was found in the intervention group when the covariables age, HDL-C level, and alanine aminotransferase activity were considered. After 1 week of PN supplementation with n-3 PUFAs, the marker levels of some oxidative stress, blood lipids, and hepatic biomarkers improved in patients with IF-II.

Intestinal failure among adults and children: Similarities and differences

Intestinal failure (IF) is a complex medical condition that is caused by a constellation of disorders, resulting in the gut's inability to adequately absorb fluids and nutrients to sustain hydration, growth, and survival, thereby requiring the use of parenteral fluid and/or nutrition. Significant advancements in intestinal rehabilitation have resulted in improved survival rates for individuals with IF. There are distinct differences, however, related to etiology, adaptive potential and complications, and medical and surgical management when comparing children with adults. The purpose of this review is to contrast the similarities and differences between these two distinct groups and provide insight for future directions, as a growing population of pediatric patients will cross into the adult world for IF management.

Incidence and development of cholestasis in surgical neonates receiving an intravenous mixed-oil lipid emulsion

BACKGROUND

Intestinal failure-associated liver disease (IFALD), initially manifesting as cholestasis, is a complication in neonates receiving parenteral nutrition (PN). Soybean oil lipid emulsion (SOLE), though implicated in IFALD, was the only US Food and Drug Administration (FDA)-approved initial intravenous lipid emulsion (ILE) for infants and children in the United States. A mixed-oil lipid emulsion (MOLE) gained popularity in patients at risk for IFALD and was recently FDA approved as an initial ILE in children. Given the presence of soybean oil in MOLE, we hypothesized that MOLE would not be effective at preventing cholestasis in surgical neonates.

METHODS

Neonates with gastrointestinal surgical conditions necessitating PN for ≥14 days and receiving MOLE (SMOFlipid) from July 2016 to July 2019 were analyzed retrospectively. Unpaired and pair-matched historical surgical neonates treated with SOLE (Intralipid) served as controls. The primary outcome measure was development of cholestasis (direct bilirubin ≥2 mg/dl).

RESULTS

Overall, 63% (10 of 16) of MOLE patients and 22% (30 of 136) of SOLE patients developed cholestasis after ≥14 days of therapy (P = 0.005). The latency to developing cholestasis was significantly shorter in MOLE patients compared with SOLE patients.

CONCLUSION

In surgical neonates, MOLE may not prevent cholestasis and should not be considered hepatoprotective. Regardless of ILE source, all surgical neonates should be closely monitored for development of IFALD. To date, there is still no ILE able to prevent IFALD.

Pharmacologic activation of hepatic farnesoid X receptor prevents parenteral nutrition-associated cholestasis in mice

BACKGROUND AND AIMS

Parenteral nutrition (PN)-associated cholestasis (PNAC) complicates the care of patients with intestinal failure. In PNAC, phytosterol containing PN synergizes with intestinal injury and IL-1β derived from activated hepatic macrophages to suppress hepatocyte farnesoid X receptor (FXR) signaling and promote PNAC. We hypothesized that pharmacological activation of FXR would prevent PNAC in a mouse model.

APPROACH AND RESULTS

To induce PNAC, male C57BL/6 mice were subjected to intestinal injury (2% dextran sulfate sodium [DSS] for 4 days) followed by central venous catheterization and 14-day infusion of PN with or without the FXR agonist GW4064. Following sacrifice, hepatocellular injury, inflammation, and biliary and sterol transporter expression were determined. GW4064 (30 mg/kg/day) added to PN on days 4-14 prevented hepatic injury and cholestasis; reversed the suppressed mRNA expression of nuclear receptor subfamily 1, group H, member 4 (Nr1h4)/FXR, ATP-binding cassette subfamily B member 11 (Abcb11)/bile salt export pump, ATP-binding cassette subfamily C member 2 (Abcc2), ATP binding cassette subfamily B member 4(Abcb4), and ATP-binding cassette subfamily G members 5/8(Abcg5/8); and normalized serum bile acids. Chromatin immunoprecipitation of liver showed that GW4064 increased FXR binding to the Abcb11 promoter. Furthermore, GW4064 prevented DSS-PN-induced hepatic macrophage accumulation, hepatic expression of genes associated with macrophage recruitment and activation (ll-1b, C-C motif chemokine receptor 2, integrin subunit alpha M, lymphocyte antigen 6 complex locus C), and hepatic macrophage cytokine transcription in response to lipopolysaccharide in vitro. In primary mouse hepatocytes, GW4064 activated transcription of FXR canonical targets, irrespective of IL-1β exposure. Intestinal inflammation and ileal mRNAs (Nr1h4, Fgf15, and organic solute transporter alpha) were not different among groups, supporting a liver-specific effect of GW4064 in this model.

CONCLUSIONS

GW4064 prevents PNAC in mice through restoration of hepatic FXR signaling, resulting in increased expression of canalicular bile and of sterol and phospholipid transporters and suppression of macrophage recruitment and activation. These data support augmenting FXR activity as a therapeutic strategy to alleviate or prevent PNAC.

What is the optimal lipid emulsion for preventing intestinal failure-associated liver disease following parenteral feeding in a rat model of short-bowel syndrome?

PURPOSE

Composite lipid emulsion (CLE) has been used for intestinal failure-associated liver disease (IFALD) to compensate for the disadvantages of soybean oil lipid emulsion (SOLE) or fish oil lipid emulsion (FOLE). However, the influence of its administration is unclear. We evaluated the effects of these emulsions on IFALD using a rat model of the short-bowel syndrome.

METHODS

We performed jugular vein catheterization and 90% small bowel resection in Sprague-Dawley rats and divided them into four groups: control (C group), regular chow with intravenous administration of saline; and total parenteral nutrition co-infused with SOLE (SOLE group), CLE (CLE group) or FOLE (FOLE group).

RESULTS

Histologically, obvious hepatic steatosis was observed in the SOLE and CLE groups but not the FOLE group. The liver injury grade of the steatosis and ballooning in the FOLE group was significantly better than in the SOLE group (p < 0.05). The TNF-α levels in the liver in the FOLE group were significantly lower than in the SOLE group (p < 0.05). Essential fatty acid deficiency (EFAD) was not observed in any group.

CONCLUSION

Fish oil lipid emulsion attenuated hepatic steatosis without EFAD, while CLE induced moderate hepatic steatosis. The administration of CLE requires careful observation to prevent PN-induced hepatic steatosis.

Fish Oil Monotherapy for Intestinal Failure-Associated Liver Disease on SMOFlipid in the Neonatal Intensive Care Unit

Intestinal failure-associated liver disease (IFALD) is a life-threatening complication of parenteral nutrition (PN) and is most prevalent in the preterm neonatal population receiving long-term PN. In this study, we report the outcome of our experience with fish oil monotherapy for IFALD in a fish oil-based combination lipid emulsion administered to preterm low birth weight infants. Fasting neonates were administered as PN according to our center's nutrition protocol. A diagnosis of IFALD was made when the serum direct bilirubin levels were >2.0 mg/dL in two consecutive measurements that were more than one week apart, without evidence of intrinsic causes of liver dysfunction. The management of IFALD was conducted by switching the lipid emulsion from combination lipid emulsion to fish oil monotherapy at 1.0 g/kg/day, infused over 24 h. Fifteen infants met the criteria for IFALD and received fish oil monotherapy. The median gestational age was 27.5 weeks and the median birth weight was 862.5 g. IFALD was successfully reversed in 11 infants (11/15, 73.3%). The median duration of fish oil monotherapy was 39 days. Direct bilirubin values were initially elevated and then steadily declined from the third week of treatment onward. The enteral tolerance increased in varying degrees during the treatment period. The mean weight gain was 26.0 g/day during fish oil monotherapy. Omegaven^® (Fresenius Kabi Austria Gmbh, Graz, Austria) at a dose of 1.0 g/kg/day was well tolerated, and no adverse events related to Omegaven use were seen. The reversal of IFALD in preterm infants on combination lipid emulsion containing fish oil was achieved by switching to fish oil monotherapy.

Composite Lipid Emulsion for the Infant at Risk of Intestinal Failure-associated Liver Disease: The Canadian Perspective

Currently, in North America we are fortunate to have a number of available options for lipid emulsions to be used in the parenteral nutrition regimens for infants and children, including for long-term parenteral nutrition given intestinal failure. Neonates and infants in particular are at risk for intestinal failure-associated liver disease (IFALD). The choice of parenteral lipid emulsion will influence the risk and severity of IFALD. The purpose of this review is to discuss the rationale for the composite lipid emulsion SMOFlipid that includes soybean, medium-chain triglycerides, olive and fish oils for IFALD, with focus on the Canadian practice and experience.

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.

New Insights Into Intestinal Failure-Associated Liver Disease in Children

Development of intestinal failure-associated liver disease (IFALD) is a common complication of long-term parenteral nutrition (PN) in children and adults. The molecular and cellular mechanisms and the phases of IFALD are now being delineated. Components of PN lipid emulsions, including plant sterols, interact with hepatic innate immune activation promoted by products of gut bacterial overgrowth/dysbiosis and altered intestinal barrier function (gut-liver axis) and by episodes of sepsis to cause cholestasis and IFALD. New therapeutic strategies, including modifications of intravenous lipid emulsions to reduce pro-inflammatory fatty acids and plant sterol content, can lower the risk of IFALD, reverse cholestasis, and reduce complications, although the significance of persisting hepatic fibrosis is unknown. This review will provide an update on advances in the pathogenesis of IFALD, newer therapeutic and preventative strategies, and challenges that confront managing patients with IFALD.

Reversal of Intestinal Failure-Associated Liver Disease by Increasing Fish Oil in a Multi-Oil Intravenous Lipid Emulsion in Adult Short Bowel-Syndrome Patients

BACKGROUND

Intestinal failure-associated liver disease (IFALD) is a serious complication of parenteral nutrition (PN). We report 2 cases of IFALD, which occurred in adult patients while on a regimen of multi-oil intravenous lipid emulsion containing fish oil.

METHODS

Patients initially received PN containing 1-g/kg/d SMOFlipid 20% (SMOFlipid). When IFALD developed, lipid composition in PN was altered to include higher proportions of fish oil.

RESULTS

Case 1 was a 23-year-old man with short-bowel syndrome. He had been fully dependent on PN for approximately 11 months with a direct bilirubin level of 15.1 mg/dL. Doses of 0.15-g/kg/d pure fish oil and 0.3-0.6-g/kg/d SMOFlipid were administered for 56 days, and IFALD was resolved 59 days after adding fish oil. Case 2 was an 85-year-old man who received extensive small-bowel resection because of internal herniation and small-bowel necrosis. He had elevated direct bilirubin levels and was diagnosed with IFALD. Fish-oil treatment was initiated after 50 days of receiving PN. The average daily amount of fish oil given was 0.14 g/kg/d. IFALD was resolved 44 days after adding Omegaven (Fresenius Kabi Austria Gmbh, Austria).

CONCLUSION

Two patients with advanced IFALD showed reversal of cholestasis by altering the lipid content of their PN to include more fish oil.

Cholestatic liver injury induced by food additives, dietary supplements and parenteral nutrition

Cholestasis refers to the accumulation of toxic levels of bile acids in the liver due to defective bile secretion. This pathological situation can be triggered by drugs, but also by ingredients contained in food, food supplements and parenteral nutrition. This paper provides an overview of the current knowledge on cholestatic injury associated with such ingredients, with particular emphasis on the underlying mechanisms of toxicity.

A Retrospective Analysis of the Effect of Combination of Pure Fish Oil with Third Generation Lipid Emulsion on Liver Function in Children on Long-Term Parenteral Nutrition

BACKGROUND

Deterioration of liver function, or intestinal failure-associated liver disease, is often observed in long-term parenterally fed children. Fish oil-based intravenous lipids have been reported to play a role in the prevention and treatment of intestinal failure associated liver disease.

METHODS

This retrospective analysis included 40 pediatric patients, (20 male and 20 female), median age 38 months (range 1.5-200 months) on long-term (≥1 month) parenteral nutrition who received the parenteral mixtures containing a combination of a third-generation lipid emulsion and pure fish oil because of laboratory liver function abnormalities. The total dose of fish oil from both emulsions for each patient exceeded 0.5 g/kg/day. Data from visits in an outpatient clinic were retrospectively analyzed using the Wilcoxon test, Mann-Whitney test, and Spearman correlation test.

RESULTS

The median time of therapy was 149 days (range 28-418 days). There was a decrease of median total and direct (conjugated) bilirubin concentration from 22.23 µmol/L (range 3.42-243 µmol/L) to 10.26 µmol/L (range 3.42-180.58 µmol/L; p < 0.005) and 8.55 (range 1.71-212.04 µmol/L) to 6.84 µmol/L (range 1.71-150.48 µmol/L; p < 0.007) respectively. A significant decrease in median alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl transferase was also observed. In 11 patients bilirubin concentrations increased or remained unchanged. When compared to the patients who responded to the combination therapy, the patients who did not respond received parenteral nutrition for a longer time prior to the start of the therapy (51 vs. 30 months; p < 0.05).

CONCLUSIONS

The mixture of an intravenous lipid emulsion containing soybean oil, medium-chain triglycerides, olive oil, and fish oil with the addition of pure fish oil emulsion may be helpful in the treatment of liver complications in children on long-term parenteral nutrition.

Fish oil protects the liver from parenteral nutrition-induced injury via GPR120-mediated PPARγ signaling

Intravenous fish oil lipid emulsions (FOLE) can prevent parenteral nutrition (PN)-induced liver injury in murine models and reverse PN-induced cholestasis in pediatric patients. However, the mechanisms by which fish oil protects the liver are incompletely characterized. Fish oil is rich in omega-3 fatty acids, which are ligands for the G-protein coupled receptor 120 (GPR120), expressed on hepatic Kupffer cells. This study tested the hypothesis that FOLE protects the liver from PN-induced injury through GPR120 signaling. Utilizing a previously described murine model of PN-induced liver injury in which mice develop steatosis in response to an oral parenteral nutrition diet, FOLE was able to preserve normal hepatic architecture in wild type mice, but not in congenic GPR120 knockout (gpr120-/-) mice. To further characterize the requirement of intact GPR120 for FOLE-mediated hepatic protection, gene expression profiles of key regulators of fat metabolism were measured. PPARγ was identified as a gene that is up-regulated by the PN diet and normalized with the addition of FOLE in wild type, but not in gpr120-/- mice. This was confirmed at the protein expression level. A PPARγ expression array further identified CD36 and SCD1, both down-stream effectors of PPARγ, to be up-regulated in PN-fed wild type mice yet normalized upon FOLE administration in wild type but not in gpr120-/- mice. Together, these results suggest that FOLE protects the liver, in part, through activation of GPR120 and the downstream effectors PPARγ and CD36. Identification of key genetic determinants of FOLE-mediated hepatic protection may provide targets for small molecule-based hepatic protection strategies.

Fish oil-based injectable lipid emulsions containing medium-chain triglycerides or added α-tocopherol offer anti-inflammatory benefits in a murine model of parenteral nutrition-induced liver injury

BACKGROUND

Fish oil (FO) intravenous lipid emulsions (ILEs) are used as a monotherapy to treat parenteral nutrition (PN)-associated liver disease and provide essential fatty acids (EFAs) needed to sustain growth and prevent EFA deficiency (EFAD). Studies have suggested that medium-chain triglycerides (MCTs) and α-tocopherol have anti-inflammatory properties.

OBJECTIVE

The purpose of this study was to test whether FO-ILEs containing MCTs and/or additional α-tocopherol decrease the inflammatory response to an endotoxin challenge compared with FO-ILE alone and preserve the ability to prevent PN-induced liver injury in mice.

METHODS

A murine model of PN-induced hepatosteatosis was used to compare the effects of ILEs formulated in the laboratory containing varying ratios of FO and MCTs, and subsequently FO- and 50:50 FO:MCT-ILE plus 500 mg/L α-tocopherol (FO + AT and 50:50 + AT, respectively). C57BL/6 mice receiving unpurified diet (UPD), PN-equivalent diet (PN) + saline, and PN + soybean oil (SO)-ILE served as controls. After 19 d, mice received an intraperitoneal saline or endotoxin challenge 4 h before being killed. Serum and livers were harvested for histologic analysis, fatty acid profiling, and measurement of systemic inflammatory markers (tumor necrosis factor-α, interleukin-6).

RESULTS

All ILEs were well tolerated and prevented biochemical EFAD. Livers of mice that received saline and SO developed steatosis. Mice that received 30:70 FO:MCT developed mild hepatosteatosis. All other FO-containing ILEs preserved normal hepatic architecture. Mice that received FO- or SO-ILE had significantly elevated systemic inflammatory markers after endotoxin challenge compared with UPD-fed controls, whereas 50:50 FO:MCT, 30:70 FO:MCT, FO + AT, and 50:50 + AT groups had significantly lower inflammatory markers similar to those seen in UPD-fed controls.

CONCLUSIONS

Mixed FO/MCT and the addition of α-tocopherol to FO improved the inflammatory response to endotoxin challenge compared with FO-ILE alone while still preventing PN-induced liver injury and EFAD in mice. There was no synergistic relation between α-tocopherol and MCTs.

Intestinal failure-associated liver disease: causes, manifestations and therapies

PURPOSE OF REVIEW

The goal of this review is to provide updates on the causes, manifestations and therapies IFALD in adults with an emphasis on recent discoveries on pathways of pathogenesis and interventions to reduce the incidence of IFALD.

RECENT FINDINGS

IFALD is a multifactorial complication of long-term home parenteral therapy. Although exact pathways are unknown, altered bile acid metabolism, microbiome dysbiosis impact on the gut-liver axis and soybean-based lipid formulations are major drivers of IFALD development.

SUMMARY

IFALD contributes to morbidity and mortality in patients on parenteral nutrition. Proactive management by a multidisciplinary team has led to improved outcomes in at-risk patients. Attention to early treatment and prevention of sepsis, introduction of nonsoybean based lipid formulations, surgical procedures such as step enteroplasties and, potentially, microbiome dysbiosis are considerations in IFLAD management.

Consanguinity and its relevance for the incidence of megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS): systematic review

BACKGROUND/PURPOSE

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a rare congenital and generally fatal cause of functional intestinal obstruction in the newborn. The cause of this syndrome is unknown. Familial occurrence and reports of consanguinity in MMIHS implies that genetic factors may have an important role in the pathogenesis of this syndrome. The aim of the study was to determine the consequence of consanguinity for the incidence of MMIHS.

METHODS

A literature search was performed using the keywords "megacystis microcolon intestinal hypoperistalsis" for studies published between 1976 and 2018. Retrieved articles, including additional studies from reference lists, were reviewed for consanguinity between parents and recurrence of MMIHS between siblings. Data were extracted for cases where familial MMIHS was present.

RESULTS

A total of 450 patients with the diagnosis of MMIHS have been reported in the literature. There were 56 (12%) cases in which familial MMIHS was confirmed, 25 families with multiple siblings and 3 families with single affected infant. Of the 25 families with multiple siblings, 22 families had 2 siblings with confirmed MMIHS and 3 families had 3 children each with MMIHS. Consanguinity between parents was confirmed in 30 cases (18 siblings and 12 individual cases). Female-to-male ratio in the 30 patients was 4.4:1.

CONCLUSION

The occurrence of MMIHS in the offspring of consanguineous parents and recurrence in siblings of healthy parents suggest that MMIHS is an autosomal recessive disorder. Pre-marital and pre-conception counselling of consanguineous populations is recommended to prevent harmful consequences.

New Nutritional and Therapeutical Strategies of NEC

Necrotizing enterocolitis (NEC) is an acquired severe disease of the digestive system affecting mostly premature babies, possibly fatal and frequently associated to systemic complications. Because of the severity of this condition and the possible long-term consequences on the child's development, many studies have aimed at preventing the occurrence of the primary events at the level of the bowel wall (ischemia and necrosis followed by sepsis) by modifying or manipulating the diet (breast milk versus formula) and/or the feeding pattern (time for initiation after birth, continuous versus bolus feeding, modulation of intake according clinical events). Feeding have been investigated so far in order to prevent NEC. However, currently well-established and shared clinical nutritional practices are not available in preventing NEC. Nutritional and surgical treatments of NEC are instead well defined. In selected cases surgery is a therapeutic option of NEC, requiring sometimes partial intestinal resection responsible for short bowel syndrome. In this paper we will investigate the available options for treating NEC according to the Walsh and Kliegman classification, focusing on feeding practices in managing short bowel syndrome that can complicate NEC. We will also analyze the proposed ways of preventing NEC.

A detailed guide to lipid therapy in intestinal failure

Intravenous lipid emulsions are an integral part of nutrition therapy in the intestinal failure patient. In addition to being a concentrated source of non-protein calories, they provide the essential fatty acids necessary for growth and development. Depending upon the oil source used in these products, complications such as intestinal failure associated liver disease (IFALD) can occur. This review will discuss the risks and benefits associated with these products, especially as they relate to the pediatric intestinal failure patient.

Intravenous Fish Oil Lipid Emulsion Prevents Catheter-Related Thromboses in Pediatric Patients with Intestinal Failure

A central venous catheter is a risk factor for deep vein thrombosis. We compared the incidence of deep vein thrombosis in children with intestinal failure patients receiving soy oil lipid emulsion (n = 35) vs fish oil lipid emulsion (n = 35). Ten deep vein thrombosis occurred in the soy oil lipid emulsion group, and none in the fish oil lipid emulsion group (P < .001).

Megacystis Microcolon Intestinal Hypoperistalsis Syndrome in Which a Different De Novo Actg2 Gene Mutation was Detected: A Case Report

INTRODUCTION

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is characterized by bladder distension without urinary tract obstruction, decreased or absent intestinal peristalsis and microcolon. Although the definitive cause remains unknown, changes in the ACTG2 gene are thought to be responsible for the intestinal and bladder hypoperistalsis.

CASE REPORT

This female newborn with MMIHS had a c.532C>A /p.Arg178Ser heterozygous de novo mutation detected in the ACTG2 gene. Normal immature ganglion cells, normal calretinin punctate positivity, maintence of smooth muscle actin immunoreactivity, and decreased numbers of interstitial cells of Cajal(ICCs) were detected.

CONCLUSION

This previously unreported c.532C>A /p.Arg178Ser heterozygous de novo mutation in the ACTG2 gene may lead to a severe form of MMIHS.

Long-term Exposure of Children to a Mixed Lipid Emulsion Is Less Hepatotoxic Than Soybean-based Lipid Emulsion

Lipid emulsions have been associated with liver injury. Newer mixed emulsions (ML), such as SMOFlipid (Fresenius Kabi, Germany), are thought to be more hepatoprotective than soybean-based emulsions (SL), such as Intralipid (Baxter). Pediatric studies comparing long-term use between the 2 are limited. This study compares the severity of hepatic injury between a prospective cohort of hospitalized children on ML (n = 20) and a historical age- and diagnosis-matched cohort of hospitalized children on SL (n = 20). Median exposure to ML and SL were 10 versus 6 weeks (P = 0.030), respectively, at similar median lipid doses (2.2 vs 2.1 g · kg · day). Using a generalized estimating equations approach, conjugated bilirubin trajectory was found to be lower in patients on ML compared with SL (P < 0.001), suggesting that prolonged exposure (≥4 weeks) to ML is associated with decreased liver injury compared with SL in hospitalized children.

A comparison of lipid minimization strategies in children with intestinal failure

PURPOSE

The purpose of this study was to compare outcomes of lipid minimization with either Intralipid (IL) or Omegaven® in children with intestinal failure (IF) who developed intestinal failure-associated liver disease (IFALD) while receiving parenteral nutrition (PN).

METHODS

A retrospective review of children with IF requiring PN who developed IFALD (direct bilirubin >2 mg/dL) while receiving IL (2009-2016) was performed. Clinical characteristics, nutritional, and laboratory values were compared between children treated with reduced IL or Omegaven®.

RESULTS

16 children were reviewed (8 treated with IL and 8 treated with Omegaven® at a median dose of 1g/kg/d). Both groups had similar demographics, small bowel length, and parenteral nutritional intake during the study (82.9±27.1 kcal/kg/d vs. 75.9±16.5 kcal/kg/d, p=0.54). The mean direct bilirubin (DBili) prior to initiating treatment was 7.8±4.3 mg/dL and 7.5±3.5 mg/dL (p=0.87) in the IL and Omegaven® groups, respectively. The IL group took a median of 113 days to achieve a DBili <0.5 mg/dL compared to 124 days in the Omegaven® group (p=0.49). There were no differences in markers of liver function or growth trajectories among groups.

CONCLUSIONS

Lipid minimization with either IL or Omegaven® has similar success in achieving a normal DBili in children with IF and IFALD without major differences in nutritional status or growth.

TYPE OF STUDY

Treatment Study LEVEL OF EVIDENCE: III.

Megacystis microcolon intestinal hypoperistalsis syndrome: Case series and updated review of the literature with an emphasis on urologic management

INTRODUCTION

Megacystis microcolon intestinal hypoperistalsis (MMIHS) is a rare disorder characterized by distended nonobstructed bladder, microcolon, and decreased intestinal peristalsis. MMIHS has a particularly poor prognosis; however, when appropriately managed, survival can be prolonged.

STUDY DESIGN

A systematic review (1996-2016) was performed with the key words "megacystis microcolon intestinal hypoperistalsis syndrome." In addition, a case series of four patients is presented as well as algorithms for the diagnosis and treatment of MMIHS.

RESULTS

135 patients with MMIHS were identified in the literature. 73% (88/121) of the patients were female, 65% underwent diagnostic biopsy (64/99), and 63% (66/106) were identified with prenatal imaging. The majority of patients were treated with TPN as well as gastrostomy or ileostomy and CIC, however 15% (18/116) received multivisceral or intestinal transplant, and 30% (22/73) had a vesicostomy. The survival rate was 57% (68/121).

CONCLUSION

Appropriate management of MMIHS patients is crucial. An enlarged, acontractile bladder in a child with bowel motility problems should be considered diagnostic. Bladder distension can be managed with CIC or vesicostomy in addition to prophylactic antibiotics if frequent urinary tract infections are present. These patients often require gastrostomy or ileostomy as well as total parenteral nutrition. This management has led to significant improvement in survival rates.

Intestinal transplantation in children: current status

Intestinal transplantation (IT) is the least common form of organ transplantation; however, it has shown exceptional growth and improvement in graft survival rates over the past two decades mainly due to better outcomes achieved during the first year of transplantation (76 % at 1 year), due to improvement in surgical techniques and the development of better immunosupressive therapies as we understand more about the relationship between the recipient and host immune system. There are still ongoing issues with chronic rejection and long-term survival. Intestinal transplantation is still an acceptable therapy for patients with intestinal failure (IF), but it is generally reserved for patients who develop severe and life-threatening complications despite standard therapies, or those who are not able to maintain a good quality of life. The purpose of this review is to describe the current status, indications, outcomes and advances in the field of intestinal transplantation.

Fish Oil-Based Fat Emulsion Reduces Acute Kidney Injury and Inflammatory Response in Antibiotic-Treated Polymicrobial Septic Mice

Acute kidney injury (AKI) is a common complication in sepsis. This study compared the effects of a fish oil-based with a mixed oil fat emulsion on remote renal injury in an antibiotic-treated septic murine model. Mice were randomly assigned to a normal control (NC) group and three septic groups. Sepsis was induced by cecal ligation and puncture (CLP). The antibiotic was injected intraperitoneally (IP) after CLP and then daily till the time of sacrifice. Three hours after antibiotic treatment, one of the septic groups was injected IP with a fish oil-based emulsion (FO), while the other two groups were given either a mixed oil emulsion (MO) or saline (SC). The septic groups were further divided into two separate time groups, with blood and kidneys samples collected at 24 h or 72 h post-CLP. The results showed that sepsis leads to the activation of neutrophils, T helper (Th)1/Th-2/Th-17 and Treg cells (p < 0.05). Plasma NGAL and mRNA expressions of renal MyD88 and TLR4 were also enhanced (p < 0.05). Compared to the SC group, the group given the fish oil-based emulsion had decreased plasma NGAL by 22% and Treg by 33%. Furthermore, renal gene expressions of MyD88 and TLR4 reduced by 46% and 62%, respectively, whereas heat shock protein 70 and peroxisome proliferator-activated receptor-γ increased by 158% and 69%, respectively (p < 0.05), at Day 3 after CLP. These results suggest that administration of a fish oil-based emulsion has favorable effects, maintaining blood T cell percentage, downregulating Treg expression, attenuating systemic and local inflammation and offering renal protection under conditions of antibiotic-treated polymicrobial sepsis.

Intravenous Lipid Emulsions in Parenteral Nutrition

Fat is an important macronutrient in the human diet. For patients with intestinal failure who are unable to absorb nutrients via the enteral route, intravenous lipid emulsions play a critical role in providing an energy-dense source of calories and supplying the essential fatty acids that cannot be endogenously synthesized. Over the last 50 y, lipid emulsions have been an important component of parenteral nutrition (PN), and over the last 10-15 y many new lipid emulsions have been manufactured with the goal of improving safety and efficacy profiles and achieving physiologically optimal formulations. The purpose of this review is to provide a background on the components of lipid emulsions, their role in PN, and to discuss the lipid emulsions available for intravenous use. Finally, the role of parenteral fat emulsions in the pathogenesis and management of PN-associated liver disease in PN-dependent pediatric patients is reviewed.