Seeing More MALS Publications

Anecdotally, I’ve seen more publications recently regarding median arcuate ligament syndrome (MALS). A recent study (JP Moak et al. J Pediatr 2021; 231: 141-147. Median Arcuate Ligament Syndrome with Orthostatic Intolerance: Intermediate-Term Outcomes following Surgical Intervention) prospectively examines the outcomes in patients with MALS and with orthostatic intolerance (OI).

Background: MALS is generally considered after other more common conditions. Typical symptoms include abdominal pain after eating or exercise and often weight loss due to fear of eating. The pain is often positional and may improve with leaning forward. The diagnostic finding of celiac artery compression may be identified in many healthy individuals (10-24% of population); thus, only severe compression, which is seen in a small number, can result in symptomatic MALS.

In this study, the key findings:

  • 31 patients with both MALS and OI were identified from 2014-2019. Median f/u after surgery was 22 months.
  • Based on questionnaires, gastrointestinal symptoms of abdominal pain, nausea, and vomiting improved in 63% (P = .007), 53% (P = .040), and 62% (P = .014) of patients, respectively. 
  • Based on questionnaires, cardiovascular symptoms of dizziness, syncope, chest pain, and palpitations improved in 45% (P = not significant), 50% (P = not significant), 54% (P = .043), and 54% (P = .037) of patients, respectively.
  • Importantly, the authors could not demonstrate a “statistical relationship between a postoperative decrease in celiac artery Doppler velocity and improvement in clinical symptoms.”
  • In an effort to gauge for a potential post-surgical placebo effect, the authors determined the degree of improvement in musculoskeletal symptoms. There was a 24% improvement which was much less than the improvement in GI symptoms.

One useful feature of this article is that the authors explicitly state how they arrive at the diagnosis of MALS. They start with an abdominal ultrasound with doppler. Criteria for suspected MALS include supine celiac artery peak systolic velocity of >300 cm/s, celiac artery/aoritic peak systolic ratio of >3:1, neutral position celiac artery peak systolic velocity of >200 cm/s, and a change in the celiac artery deflection angle of >50 degrees between inspiration and expiration. If ultrasound is abnormal, the authors obtained an enhanced CT to image inspiratory and expiratory changes in the celiac artery deflection angle, the area of stenosis, poststenotic dilation, and the collateral blood vessels. If there are discrepancies between U/S and CT, a celiac arterial angiogram is obtained.

The authors conclude that there “were minimal improvements in neurologic or psychological symptoms after MALS surgery, despite their common occurrence among patients with POTS.”

My take: This study, in agreement with others, showed that about 60% had improvement in GI symptoms including pain, nausea and vomiting. In those with OI, most continued with impaired health. Overall, MALS as a clinical entity remains a ‘needle in a haystack.’

Related blog posts

Real-World = Partially-Treated Celiac Disease

A recent prospective observational study reinforces the idea that most people with celiac disease are unable to accomplish a strict gluten-free diet (GFD): JP Stefanolo et al. Clin Gastroenterol Hepatol 2021; 19: 484-491. Real-World Gluten Exposure in Patients With Celiac Disease on Gluten-Free Diets, Determined From Gliadin Immunogenic Peptides in Urine and Fecal Samples

The investigators enrolled 53 adults with celiac disease (CD) for at least two years and followed symptoms as well as stool/urine testing for gluten immunogenic peptide (GIP). “GIP in stool can detect gluten consumption of more than 40 mg/d and the urine tests are positive from 40 and 500 mg/d of gluten.”

Key findings:

  • Over the 4-week study period, weekend samples (urine) identified 70% of patients excreted GIP at least once, compared with 62% during weekdays (stool).
  • Patients had a median of 3 exposures during the 4 weeks.
  • Also, the authors noted increases in GIP excretion towards the end of the study. “This suggests a potential Hawthorne effect that could be explained by a decrease in hypervigilance that often is seen in a context of research studies.”

The authors note that GIP “excretions of greater than 2 mcg/g in stool or greater than 12 ng/mL in urine can induce mucosal damage in almost 100% of patients.”

My take: This study adds to the body of literature emphasizing the high rate of inadvertent gluten exposure.

Related blog posts:

Before and After at Lake Michigan shoreline (1 month apart in Evanston, IL)

Early January -Evanston, IL
Early February -Evanston, IL

COVID-19 Vaccine vs Variants

A recent NEJM letter indicates that serum from individuals (n=15) who received the Pfizer vaccine is adequate to neutralize tested variants.

Y Liu et al. NEJM 2021; DOI: 10.1056/NEJMc2102017. Full text Neutralizing Activity of BNT162b2-Elicited Serum

“All the serum samples efficiently neutralized USA-WA1/2020 and all the viruses with variant spikes.”

1. When You Are Fully Vaccinated 2.Outcomes of Duodenal Atresia and Stenosis

  1. CDC Recommendations: When You’ve Been Fully Vaccinated
  2. GS Bethell et al. JPGN 2021; 72: 239-243. One-year Outcomes of Congenital Duodenal Obstruction: A Population-based Study

This prospective observational study provides helpful outcome data for infants (n=80) born with congenital duodenal obstruction (CDO).

Key findings (also see infographic below):

  • Though there was an 8.4% overall mortality, there were no deaths directly attributed to CDO. 69% had associated anomalies.
  • Median length of stay after repair was 20 days; at 28 days following repair, 76% had been discharged home
  • Failure to achieve full enteral feeds was NOT related to CDO (due instead to other gastrointestinal anomalies). Mean time for full feeds was 13 days post-op; 90% reached full enteral feeds at 28 days.
  • Repair type: 80% had duodenoduodenostomy, 14% had duodenojejunostomy, the others: membrane incision (n=1), membrane resection (n=2), and duodenoplasty (n=2)

My take: This data will inform clinicians of expected outcomes in this population. I hope this cohort is followed long-term to provide more information about long-term outcomes including frequency of pancreatitis.

COVID Vaccine Myths and Facts from ACG

ACG: 1Fact/1Myth: Dispelling Misinformation on COVID-19 Vaccine

Some of the slides:

Full set of Slides: ACG_COVID_Vaccine Slide Set PDF

Related blog posts:

COVID-19 Vaccine in Israel & Effectiveness for Variants

From BBC (1/25/21): Moderna vaccine appears to work against variants

An excerpt:

“For the Moderna study, researchers looked at blood samples taken from eight people who had received the recommended two doses of the Moderna vaccine. The findings are yet to be peer reviewed, but suggest immunity from the vaccine recognises the new variants. Neutralising antibodies, made by the body’s immune system, stop the virus from entering cells.

Blood samples exposed to the new variants appeared to have sufficient antibodies to achieve this neutralising effect, although it was not as strong for the South Africa variant as for the UK one. Moderna says this could mean that protection against the South Africa variant might disappear more quickly.”

More on COVID-19 Vaccines

Yesterday, Evan Anderson (infectious disease) shared some updates on COVID-19 vaccines.

  • Dr. Anderson noted that more research is needed in children, pregnant women and immunocompromised populations. Immunocompromised patients may have a lower response rate to vaccination.
  • The South African 501Y.V2 COVID-19 variant may be less responsive to neutralization from donor plasma and the vaccines may be less effective in this variant.
  • He reviewed ACIP recommendations -available from CDC website as well
  • Dr. Anderson noted there is a good response to vaccination even in those with a lack of adverse effects with vaccination
  • Immunity after vaccination: data has been published showing good antibody levels at 3 months. Moderna has stated that they expect vaccine will provide immunity for at least a year
  • Immunity after infection with COVID-19: at least 3 months. Those with milder infection are more likely to get reinfected.
  • Antibody testing after vaccination to assess for immunity is not recommended