Aspen Webinar 2021 Part 4 – IFALD Update

More from Aspen Webinar 2021. This blog entry has abbreviated/summarized several presentations. Though not intentional, some important material is likely to have been omitted; in addition, transcription errors are possible as well. An excellent review from Dr. Sokol.

What’s New with IFALD Ronald Sokol

Key points:

  • Biliary cirrhosis related to parenteral nutrition has been the major indication for small bowel  transplantation/multi-visceral transplantation. IFALD presentations: Steatosis, biliary tract disease and cholestasis
  • Conjugated bilirubin >2.5 had RR 22.5 for mortality (prior to availability of intestinal transplantation)
  • Even after weaning off PN, studies have shown long-lasting fibrosis and steatosis in more than 40% of patients (>8 yrs off PN)
  • Intestinal microbiome is altered in patients with IFALD
  • Puder M et al. (Ann Surg 2009; 250: 395) showed that fish oil (at lower doses) was associated with improvement/resolution of parenteral nutrition associated cholestasis (PNAC)
  • Lipid reduction also is associated with cholestasis resolution
  • Treatments: Advance enteral feeds, lipid modulation, prevent CLABSI, treat bacterial overgrowth, GLP-2, and STEP procedure/tapering
  • SMOF lipid allows full dosing of lipids (3 gm/kg)
  • Caution with Fish oil (omegaven): 1. Does not prevent hepatic fibrosis progression 2. Reduction of lipid doses can have negative effects on brain growth
  • Lipid management has been crucial in reducing the number of children needing intestinal transplantation

Some of the slides:

IBAT Inhibitors Frederick Suchy

Key  points:

  • IBAT inhibitors block intestinal absorption of bile acids/disrupt enterohepatic circulation; this leads to augmented bile acid excretion in stools
  • IBAT inhibitors may reduce liver damage in the setting of cholestasis/accumulation of toxic bile acids
  • Potential diseases for IBAT inhibitors include Alagille syndrome and PFIC
  • Van Wessel et al (J Hepatol 2020; 73: 84-93) correlated survival with PFIC1/PFIC2 with bile acid levels and showed improvement in survival in those with surgical biliary diversion
  • Goals for IBAT inhibitor trials: improvement in pruritus, bile acids, reduced ALT, hepatic fibrosis, HCC and need for liver transplantation
  • Marixibat is available for use as an FDA approved breakthrough medication for Alagille and PFIC2 in pediatric patients older than 1 year
  • Odexibat is designated as an orphan drug for Alagille, PFIC, PBC, and biliary atresia
  • Safety appears good with IBAT inhibitors. Fat soluble vitamin monitoring is needed

Case report: Alejandro Velez Lopez

3 yo presented with fatigue and jaundice, 3 weeks after COVID-19 infection. She was not taking any medications.  Labs:  ALT 939, AST 1321, T bili 5.5, D bili 0.9, INR 2, Plts 174, Hgb 12.8, LDH 1297. remained positive for SARS-CoV2 by PCR. Acetaminophen -no exposure.  Evaluation: LKM 1:1280. Neg ANA, NL Ferritin, NL sIL2r, Other viral studies negative, NL IgG. Developed encephalopathy with NH4 317, INR peaked at 2.8.  Treated with steroids, rifaximin and lactulose.  Liver biopsy showed sub-massive necrosis and fibrosis (indicative of  autoimmune hepatitis, likely triggered or exacerbated by COVID-19).  Patient responded to medical therapy and did not require liver transplantation.

Liver Shorts -November 2020 and Georgia’s ACA Waiver

E Zuckerman et al. Clin Gastroenterol Hepatol 2020; 18: 2544-53. Full text link: Eight Weeks of Treatment With Glecaprevir/Pibrentasvir Is Safe and Efficacious in an Integrated Analysis of Treatment-Naïve Patients With Hepatitis C Virus Infection

  • “We pooled data from 8 phase 2 or phase 3 trials of treatment-naïve patients with HCV genotype 1 to 6 infections, without cirrhosis or with compensated cirrhosis, who received 8 weeks of glecaprevir/pibrentasvir.” (n=1248) Key finding:  Overall rates of sustained virologic response at post-treatment week 12 were 97.6% (1218 of 1248) in the intention to treat (ITT) and 99.3% (1218 of 1226) in the modified ITT populations.

JA Silverman et al. JPGN 2020; 71: 283-287. Composite Lipid Emulsion for the Infant at Risk of Intestinal Failure–associated Liver Disease: The Canadian Perspective

This review discussed the use of SMOFlipid that includes soybean, medium-chain triglycerides, olive and fish oils. Key points:

  • “Lipid minimization strategies have also been shown to reverse IFALD [intestinal failure associated liver disease]. There are, however, considerable concerns regarding adequate weight gain, compromise to neurodevelopment, and EFAD [essential fatty acid deficiency]”
  • “Thee is actually considerable safety data for CLE [composite lipid emulsion] in neonates, albeit over the short term.”
  • “In Canada, CLE is currently the lipid emulsion of choice for all infants at risk of IFLAD.”

T Mitchell et al. Clin Gastroenterol Hepatol 2020; 18: 1584-1591. Decreased Physical Working Capacity in Adolescents With Nonalcoholic Fatty Liver Disease Associates With Reduced Iron Availability

  • Methods: “We collected information on weight-adjusted, submaximal physical work capacity (PWC), ultrasound-determined hepatic steatosis, iron indices, and hematologic and metabolic parameters from 390 female and 458 male participants of the Raine Study—a longitudinal study of disease development … in Western Australia”
  • Key finding: “Fourteen percent of the cohort had NAFLD. PWC was significantly reduced in adolescents with NAFLD compared to adolescents without NAFLD (reduction of 0.17 W/kg, P = .0003, adjusted for sex and body mass index [BMI])… we found NAFLD to be associated with decreased cardiorespiratory fitness, independent of BMI. The relationship between transferrin saturation and PWC in adolescents with NAFLD indicates that functional iron deficiency might contribute to reductions in cardiorespiratory fitness.”

In other news, Georgia has received approval for an affordable care act waiver. From the AJC (October 15, 2020): Kemp’s health care waivers win federal approval Two key points:

  • “Thousands of Georgia’s poor and uninsured adults who meet a work or activity requirement will soon be eligible for Medicaid, with perhaps 50,000 added to the rolls within two years…And more than 350,000 very poor, uninsured Georgia adults still won’t meet Georgia’s requirements for Medicaid”
  • “At the same time, the 400,000 Georgians who bought individual health insurance plans on the federal Affordable Care Act shopping website will find they can’t do that anymore. Instead they will be directed to contact information for private brokers or insurance companies”
These tweets were posted on 11/2/20.

Medical Progress for Intestinal Failure Associated Liver Disease

A recent review (WS Lee, RJ Sokol. J Pediatr 2015; 167: 519-26) provides a good explanation of the role of various intralipids and intestinal microbial dysbiosis in the setting of intestinal failure-associated lipid disease (IFALD).

The review discusses criteria for IFALD (e.g. conjugated bilirubin ≥2 mg/dL & parenteral nutrition ≥14 days), the epidemiology, and the pathogenesis. Potential risk factors and level of evidence for these risk factors is noted in Table 1.

Table 2 describes the evidence supporting suggested strategies for the prevention of IFALD. The effectiveness and recommendation levels for these strategies are generally very low and weak based on reviews by ASPEN and the American Pediatric Surgical Association.  Among the strategies, reduction of lipid emulsion to ≤ 1 g/kg/day has some of the strongest support in this table but is still regarded as level III evidence and described as “probably effective.” Other strategies reviewed included ethanol locks, multidisciplinary team management, use of ursodeoxycholic acid/bile acid supplementation, cycling of parenteral nutrition, use of prokinetics, removal of manganese and copper from parenteral nutrition, and antibiotic use to prevent bacterial overgrowth.

With regard to alternative intravenous lipids (eg. fish oil, or SMOF mixture):

  • “Although a properly powered randomized controlled trial has not been conducted, current evidence suggests that the use of FO-ILE [fish oil -intravenous lipid emulsion] is effective in reversing the established cholestasis associated with IFALD, but there is insufficient evidence for a preventative effect in neonates.”
  • “Most studies have been retrospective, used a historical comparison group, used different doses of lipid, and were conducted in patients with quite advanced IFALD.”
  • Use of FO-ILE improves biochemical parameters, but has not been shown to “improve other important long-term clinical outcomes, such as severity of hepatic fibrosis.”
  • In addition, reduced ILE and FO-ILE may result in other sequelae such as cognitive developmental delay. “Recently, lower brain weight and alterations of brain PUFA content were demonstrated in newborn piglets receiving total PN with reduced dose SO-ILE or FO-ILE compared with normal dose SO-ILE.”

My take: This review underscores how little is known about the approaches often recommended for management of IFALD.

Related blog posts:

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications/diets (along with potential adverse effects) should be confirmed by prescribing physician/nutritionist.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

Empty Road

Looking Beyond the Headline for Ultra-Short Bowel Syndrome

A quick glance at a recent study (JPGN 2014; 58: 438-42) suggests a favorable outlook for patients with ultra-short bowel syndrome (U-SBS). U-SBS has been defined as having a residual small bowel length <10 cm distal to the ligament of Treitz.  A more cynical definition by a colleague years ago was that U-SBS was when patients can fart and burp at the same time.

Looking at the details:  This study enrolled 11 patients into a prospective Italian database since 2000 and examined their outcomes.  Inclusion criteria included U-SBS diagnosed in the neonatal period (<28 days) and necessitating home parenteral nutrition at discharge.

The demographics note that these patients were bigger at birth and less premature than typical series of patients with SBS:

  • Only one of the patients had necrotizing enterocolitis as the sole underlying disease and six patients had volvulus.
  • All but two had ≥50% of their colons, with five having their entire colon.
  • All but one of these patients had gestational age ≥32 weeks and only two  patients had documented birth weight less than 2300 gm.

The authors note that these patients currently receive SMOFlipid as outpatients and Omegaven as inpatients.  All patients receive some enteral feedings.  Loperamide is used selectively.


  • Inpatient hospital care ranged from 23 to 104 days/year, but had improved during the last year of followup.
  • With >5 years of followup, 2 of the 11 patients had died.  One of these patients had severe intestinal failure associated liver disease (IFALD) despite use of Omegaven.
  • One patient underwent isolated intestinal transplantation.
  • No children in this series underwent a bowel-lengthening…”given the shortness of the residual small bowel, the gain of length after any procedure will not significantly improve absorption.”

Given their results, the authors note that despite recommendations for early referral for intestinal transplantation in patients with U-SBS, this may not result in a survival benefit.  They note a study by Pironi et al (Gut 2011; 60: 17-25) that showed that among 80 intestinal transplant candidates, 5-year survival was greater in those who were not transplanted.

Bottomline: This small cohort shows that certain populations of U-SBS may do well clinically for a long time with medical management. Caution should be used in extrapolating these results to SBS patients with different demographics.

Parenteral Omega-3 Lipid Emulsions and Risk of Bleeding

A recent study indicates that patient’s placed on omega-3 lipid emulsions (eg. Omegaven) may be at risk for bleeding due to platelet dysfunction (J Pediatr 2014; 164: 652-4).

While omega-3 lipid emulsions have received a lot of attention due to improvements in intestinal failure associated liver disease (IFALD) (see previous links to prior posts below), the amount of data supporting their usage and potential advantages compared with standard lipids at similar dosing remains limited.

This case report describes a 9-month old who developed life-threatening hemorrhage following a standard central line placement.  Due to difficulty stopping the bleeding, the patient’s omegaven was discontinued.  Standard workup for bleeding disorders were negative.  Subsequently, the authors investigated clot formation and platelet function in a neonatal animal model.

Key Result: Piglets treated with omegaven had a doubling of time to clot formation and marked platelet agonist inhibition.

The discussion notes that “there is an acknowledged risk of high dose O3FA lipids [omegaven] increasing bleeding time because of competitive inhibition of AA [arachidonic acid] production, hence decreased TxA2 [thromboxane A2].  In addition, platelet-derived growth factor-like protein and endothelial platelet activation factor are decreased.”

Take home points (from the authors):

  • “the case report and piglet studies together demonstrate that there is potential for a significant antiplatelet effect and inhibition of the coagulation cascade with O3FA therapy…”
  • “We would suggest discontinuation of Omegaven therapy 72 hours preoperatively in high-risk cases where bleeding may be difficult to directly control.”
  • “Institutionally, we have abandoned the sole use of Omegaven therapy.”

Related blog posts:

Fish Oil, IFALD, and Liver Fibrosis

While there has been a lot of enthusiasm for the use of fish oil as a potential breakthrough for intestinal failure-associated liver disease, this has been based largely on the use of surrogate markers of liver disease and based on comparisons with the historical use of conventional intravenous lipids.  The latter problem has been discussed before on this blog (see links below).

A recent study begins to address the issue of surrogate markers by reinforcing the viewpoint that improvements in bilirubin and aminotransferases may not translate into improvement in liver fibrosis or other clinically-meaningful outcomes (JPGN 2013; 56: 364-69).  A previous pediatric study (J Pediatr 2010; 156: 327-31) showed failure of regression of hepatic fibrosis in 2 children receiving FOE therapy.

In this study, the authors sequentially examined 6 children on fish-oil lipid emulsions (FOE) who underwent multiple liver biopsies.  In this cohort, 5 of 6 children had gastroschisis and the mean gestational age was 35 weeks.  Median intestinal (small bowel) length beyond the ligament of Treitz was 26 cm and most children retained about 2/3rds of their colon.  Liver biopsies were obtained at the time of other open abdominal operations (eg. serial transverse enteroplasty, stoma takedown).

Key results:

  • Liver fibrosis persisted in 2 cases, progressed in 3 cases, and regressed in 1 case.
  • Histology and biochemistries indicated improvement in cholestasis and inflammation.
  • One patient has weaned off parenteral nutrition, two patients underwent isolated small bowel transplantation due to recurrent line infections, and three patients receive 25-40% of their calories parenterally.

The biggest limitation of this study besides the small number of enrolled patients was the relatively short  time period that was studied.  Only one patient who was studied had data reported for FOE more than 36 weeks.  The oldest age of any patient at the time of their last biopsy was 131 weeks old.

Take-home points:

  • “There is no direct evidence to support any one [proposed theoretical benefit of FOE] as clinically meaningful as yet.”
  • “Lipid minimization strategies are also effective in reducing cholestasis.”
  • “Many of the biopsies taken right at the time of FOE initiation” showed significant fibrosis which “speaks to how quickly fibrosis can develop.” One child had stage 2 fibrosis at 14 weeks of life.
  • “The biochemical resolution of cholestasis is at best a weak surrogate marker ..for…enteral independence and overall survival.”  “These findings make a strong case for early referral of children with short bowel syndrome to specialized intestinal rehabilitation centers.”

Related blog posts:

Outcomes with STEP procedure

While the serial transverse enteroplasty (STEP) procedure has been considered a major advance in the management of short bowel syndrome (SBS), long-term data are in short supply.  5-year outcomes from Toronto with regard to 12 patients offers some insight into the effectiveness of this operation (J Pediatr Surg 2012; 47: 931-37).

The 12 patients selected for this study received STEP prior to January 2005.  The other 19 STEP patients at this institution were not included due to lack of long-term followup. Among the 12 patients, 6 had intestinal atresia, 3 had NEC, 1 had gastroschisis, 1 had volvulus, and 1 had Hirschsprung disease.

Key results:

  • 7 patients weaned off parenteral nutrition successfully –one took 4 years; one patient continued on parenteral nutrition.
  • 2 patients died of liver failure, 2 patients received liver-intestinal transplant.
  • STEP increased small bowel length from a median of 110 cm to 128 cm.  The dilated portion that received STEP changed from a median length of 31 cm to a median of 57 cm; this resulted in a median bowel caliber change from 6 cm to 2 cm.  The overall effect was an overall increase in small bowel length of 40%.
  • Biochemical markers improved.  For example, citrulline increased from 18 μmol/L pre-STEP to 33 μmol/L at 12 months, and 48 μmol/L at 5 years post-STEP.  Fecal fat malabsorption (based on 72 hr collections) improved from >40% to ~20% 6 months after STEP.
  • Indications for STEP: bacterial overgrowth (n=7), intestinal failure associated liver disease (IFALD) (n=5).
  • Complications: suture line bleeding due to ulcerations in one patient, 2 patients had leakage at suture line in immediate post-op period.  The latter 2 cases were ascribed to limited experience with technique; the surgeons now use a 2.5 mm staple instead of a 3.5 mm.

Take home points:

  1. Authors comment: “our approach is to only consider patients who plateau in their parenteral nutrition weaning or develop complications such as PN cholestasis…patients who continue to show intestinal adaptation are not offered surgery despite the presence of bowel dilatation”
  2. “It takes up to an average of 1 to 2 years to see the improvement in intestinal function after a STEP.”  While the authors may be correct about this timeframe, in their figure 3, two came off PN at one month post-STEP, four achieved this goal 6 months after STEP and another 12 months following STEP.
  3. Why does STEP work? Either improved intestinal function due to increased absorptive surface or due to healing of existing mucosa; the latter may occur with resolution of dilated,  inflamed bowel associated with bacterial overgrowth.

Related blog entries:

Four advances for intestinal failure | gutsandgrowth

IFfy outcome | gutsandgrowth

Additional STEP references:

  • -JPGN 2007; 45: 174, 257.
  • -J Pediatr Surg 2003; 38: 425-429. Initial description of STEP procedure from Kim HB et al.
  • -Clin Gastro & Hep 2006; 4: 1237. STEP in 4 patients helped to decrease or eliminate TPN requirements.
  • Images for step procedure

Optimizing lipids to minimize cholestasis

As discussed in previous blog entries (PNAC, PNALD, and IFACMore on PNACFour advances for intestinal failure), the right amount of lipid and the type of lipid both can contribute to parenteral nutrition associated cholestasis (PNAC).  More information about SMOFlipid which is a complex mixed-type lipid emulsion derived from soybean, coconut, olive, and fish oils is available (JPGN 2012; 54: 797-802).  SMOF contains 30% soybean oil, 30% MCT, 25% monounsaturated fatty acids, and 15% fish oil.

This study had a retrospective cohort comparison design & examined serum bilirubin over 6 months in children with PN-associated cholestasis (PNAC).  In one cohort, 8 patients received the SMOFlipid and the other 9 patients continued on Intralipid (IL).

The SMOF cohort was receiving 81% of caloric needs as PN at entry whereas the IL cohort was receiving 92%.  Six months later, SMOF cohort was receiving 68% of caloric needs as PN compared with 50% for IL cohort.  Nevertheless, the SMOF group had improved cholestasis with a median bilirubin drop of 99 μmol/L compared with an increase of 79 μmol/L among IL patients.  Overall, 5 of 8 children in the SMOF group had resolution of jaundice compared with 2 of 9 in the IL group.

While the authors state that SMOF may have important properties to prevent PNALD, the study has limited ability to draw any firm conclusions.

The authors state that no other treatment innovations were introduced; however, the authors overlook the large discrepancy in lipid volume administered.  The IL group was receiving much more lipid both before and during study.  Prior to entry of study, the IL group was receiving about 3.1 g/kg/day whereas the SMOF group about 2 g/kg/day; the SMOF group continued initially at the same lipid dosing with the new formulation.  This is one of the problems with historical controls.  While the authors might believe that the cholestasis improved because of the lipid content, the key factor may in fact be the amount of lipid given.

In the same issue (JPGN 2012; 54: 803-11), specific plant sterols (PS) were elevated among neonates with intestinal failure-associated liver disease (IFALD).  This study looked at 28 neonates and 11 children from Finland who required PN for more than 28 days.  Specific markedly-elevated PS included stigmasterol, sitosterol, avenasterol and campesterol (Table 4 in study).  Some of these PS in the neonates were more than 20-fold higher than healthy controls.