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.’

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#NASPGHAN19 Postgraduate Course (Part 3)

Here are some selected slides and notes from this year’s NASPGHAN’s postrgraduate course. There may be some errors of omission or transcription.

Link to the full NASPGHAN PG Syllabus 2019 (Borrowed with permission)

Functional/Motility Session

95 Carlo Di Lorenzo, MD, Nationwide Children’s Hospital. Evaluation Testing for functional disorders: The indispensable, the useless, the dangerous and treatment strategies in NERD and functional dyspepsia.

This was the best lecture of the day!!! (Hence a lot of slides follow)

  • Families never complain about doctors missing irritable bowel syndrome and anxiety. They may complain about missing diagnosis which are controversial with regarding to chronic pain (‘chronic appendicitis, gallbladder dyskinesia, ‘mild’ IBD, median arcuate ligament syndrome, and food allergies)
  • Functional disorders, but not organic disorders, can cause ‘constant’ pain. “Tried everything.”  Functional disorder patients frequently have side effects with everything.
  • Listen to patient and sit while listening.
  • Early diagnosis of functional disorder associated with higher long-term resolution
  • Testing –only tests that are cost-effective: celiac disease and stool calprotectin.  “Don’t get KUB for constipation.”
  • Endoscopy does not improve outcomes in children with functional GI disorder (FGID)
  • Eosinophilic esophagitis (EoE) treatment does not help abdominal pain but can help if patient has dysphagia
  • Abdominal wall pain is often overlooked.  Check Carnett sign.

 

112 Peter Kahrilas, MD, Northwestern Medicine  Achalasia

  • Achalasia likely develops after an infection in a susceptible host
  • Discussed POEM as newer treatment. It appears to be more effective than either Heller myotomy or pneumatic dilatation in adults.  So far, there is limited experience in pediatrics though it appears to mirror adult experience

124 Julie Khlevner, MD, Morgan Stanley Children’s Hospital Evaluation and treatment strategies in NERD and functional dyspepsia

  • In patients with NERD, hypermetabolizers of PPIs may need higher dosing.
  • Neuromodulators (not FDA approved) used for PPI-nonresponders.  Cognitive behavioral therapies may be helpful as well.
  • Functional dyspepsia with reflux symptoms are more likely to respond to PPIs than those with dyspepsia symptoms
  • A Japanese herb, rikkunshito, may be helpful for functional dyspepsia

136 Robert J. Shulman, MD, Children’s Nutrition Research Center Role of diet in managing of IBS

Key points:

  • Vast majority of low FODMAPs studies show “too much bias” due to lack of blinding in study designs.
  • Nutritionists are needed to guide diet.  Kids (families) do not follow these diets well.
  • Most who are going to respond to diet will do so within 7-10 days.

Disclaimer: NASPGHAN/gutsandgrowth assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. The discussion, views, and recommendations as to medical procedures, choice of drugs and drug dosages herein are the sole responsibility of the authors. Because of rapid advances in the medical sciences, the Society cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure. Some of the slides reproduced in this syllabus contain animation in the power point version. This cannot be seen in the printed version.

 

What to Make of Median Arcuate Ligament Syndrome

A recent study (C Stiles-Shields et al. JPGN 2018; 66: 71) reports on 32 cases of median arcuate ligament syndrome (MALS) from a single center, 2011-17.  To me, this is an astounding number of individuals who were operated on for this disorder.  As the authors note, “MALS remains a controversial and vexing condition. 13% to 50% of healthy patients may exhibit radiographic features of celiac artery compression.”

While the authors note that pain symptoms improved significantly, they report that “comorbid psychological conditions were common, occurring in about half the sample before and after surgery.”

My take: If one finds celiac artery compression and suspects MALS, it is unclear to me if an operation is indicated and how to determine when it is indicated.

Related blog post:

Proctor Creek Trail