Median Arcuate Ligament Syndrome

Median arcuate ligament syndrome (MALS), also known as celiac artery compression syndrome, is a rare condition caused by extrinsic compression of the celiac artery and/or celiac ganglion by the median arcuate ligament and diaphragmatic crura, resulting in foregut ischemia and neuropathic pain. [1-2] It is a diagnosis of exclusion with a female predominance (4:1), typically affecting patients aged 30–50 with a thin body habitus. [2] The median time from symptom onset to surgical referral is approximately 10.5–24 months. [3-4]

The following algorithm from JAMA Surgery outlines the recommended diagnostic and management approach:

• Key HPI questions: Characterize abdominal pain — location (epigastric), timing (postprandial vs. constant), relation to meals, exercise, and body position [1-2]
• Symptom characterization: Chronic epigastric pain (94%), postprandial pain (80%), nausea/vomiting (56%), unintentional weight loss (50%), bloating (39%), diarrhea (30%), exercise-induced pain (8%) [2][5]
• Timing/triggers: Pain worsens after eating (increased mesenteric blood demand) and with exercise; may be mitigated by leaning forward or drawing knees to chest [2]
• Progression: Typically chronic and progressive over months to years; median symptom duration before diagnosis is ~24 months [3]
• Important negatives: Ask about bloody stools, fever, jaundice, prior abdominal surgeries, and history of atherosclerotic disease to exclude other etiologies

• Acute severe abdominal pain with hemodynamic instability (consider acute mesenteric ischemia or celiac artery thrombosis) [6]
• Rapid, severe weight loss (>25 lbs reported in 35.6% of one cohort) suggesting significant foregut ischemia or malignancy [7]
• Signs of peritonitis — suggests bowel infarction, not typical MALS
• GI bleeding — not characteristic of MALS; should prompt evaluation for alternative diagnoses
• Celiac trunk thrombosis has been reported as a rare complication, particularly in patients with prothrombotic conditions such as antiphospholipid syndrome [6]

• No specific pharmacologic treatment for MALS; management is primarily surgical [1-2]
• Symptomatic relief: Analgesics (NSAIDs, acetaminophen), antiemetics for nausea, proton pump inhibitors if concurrent GERD/gastritis suspected
• Celiac plexus block (percutaneous) is used both diagnostically and therapeutically — a positive response may predict surgical success [2][8]
• Avoid: Vasoconstrictors (ergotamines, triptans, cocaine) that could worsen mesenteric ischemia
• Caution: Opioid dependence is a risk given chronic pain; psychiatric comorbidities are common and may predict poorer surgical outcomes [9]

• Small, frequent, low-fat meals to reduce postprandial mesenteric blood flow demand and minimize pain [10]
• Adequate hydration and nutritional supplementation, especially in patients with significant weight loss
• Avoid large meals and high-fat foods that maximally stimulate splanchnic blood flow
• Nutritional support (enteral or parenteral) may be necessary in severely malnourished patients preoperatively
• Nonoperative management includes dietary modifications, though outcomes are worse compared with surgical treatment [1][10]

• GI: Postprandial pain, nausea, vomiting, diarrhea, bloating, sitophobia (fear of eating), weight loss
• Vascular: Symptoms of other vascular compression syndromes (nutcracker syndrome, May-Thurner syndrome — especially in patients with connective tissue disorders) [7]
• Psychiatric: Depression, anxiety — psychiatric comorbidities are prevalent and may impact surgical outcomes [9]
• Autonomic: Dysautonomia symptoms (POTS, orthostatic intolerance) — preliminary data suggest worse surgical outcomes [9]
• Musculoskeletal/Connective tissue: Joint hypermobility, skin hyperextensibility — association with hypermobile Ehlers-Danlos syndrome (hEDS) [7]

• Collateral: Duration and extent of weight loss, dietary intake, prior GI workup results, prior imaging, and number of specialists seen (diagnosis is frequently delayed)
• Family history: Connective tissue disorders (Ehlers-Danlos syndrome), hypercoagulable states (antiphospholipid syndrome) [6-7]
• Social context: Impact on quality of life, functional status, employment; assess for eating disorders as a differential; screen for psychiatric comorbidities [9]

• Female sex (4:1 ratio) [2]
• Age 20–50 years (median age ~38–40 in surgical series) [3][11]
• Thin body habitus / low BMI — less periaortic fat allows greater ligament compression; higher BMI inversely associated with symptom improvement after surgery [8][12]
• Connective tissue disorders — particularly hypermobile Ehlers-Danlos syndrome [7]
• Anatomic variant: Low insertion of the median arcuate ligament crossing the celiac axis origin [2][13]
• Mast cell activation syndrome (MCAS) — may overlap with and confound MALS symptoms; correlated with persistent symptoms after surgery [14]

• Peptic ulcer disease / gastritis — most common mimic; rule out with EGD
• Biliary disease (cholelithiasis, biliary dyskinesia) — RUQ ultrasound, HIDA scan [2]
• Chronic pancreatitis — lipase, CT abdomen
• Gastroparesis — gastric emptying study
• Functional dyspepsia / disorders of gut-brain interaction (DGBIs) — significant symptom overlap; must be excluded before MALS diagnosis [15]
• Chronic mesenteric ischemia (atherosclerotic) — typically older patients with cardiovascular risk factors; CTA distinguishes from MALS [13]
• Superior mesenteric artery syndrome — duodenal compression
• Malignancy (pancreatic, gastric) — CT, EGD
• Hyperkinetic gallbladder dyskinesia — GBEF >80%; overlapping presentation with MALS [16]
• Cannot-miss: Acute mesenteric ischemia, celiac trunk thrombosis, pancreatic malignancy [6]

• Prior extensive GI workup (EGD, colonoscopy, HIDA scan, CT) — typically negative in MALS [2]
• Previous cholecystectomy or appendectomy without symptom resolution
• History of connective tissue disorders (hEDS), dysautonomia, MCAS [7][9][14]
• Psychiatric history (depression, anxiety) — impacts prognosis [9]
• Prior abdominal surgeries (adhesions may complicate surgical approach)

• Vital signs: Usually normal; tachycardia or hypotension suggests acute complication
• Abdominal exam: Epigastric tenderness; epigastric bruit that is amplified with expiration (present in ~30% of younger patients, but not specific — found in 16% of asymptomatic individuals) [2]
• General: Thin habitus, signs of malnutrition/cachexia, temporal wasting
• Focused maneuvers: Auscultate epigastrium during deep expiration (bruit accentuation); assess for joint hypermobility if connective tissue disorder suspected
• Expected vs. concerning: Exam is often unremarkable; peritoneal signs or hemodynamic instability should prompt emergent evaluation

• Recommended labs: CBC, CMP, lipase, lactate, hepatic function panel — primarily to exclude other diagnoses
• Expected abnormalities: Labs are typically normal in MALS [2]
• Rule-out labs: Lactate (if acute ischemia suspected), amylase/lipase (pancreatitis), celiac disease panel, H. pylori testing
• Nutritional markers: Albumin, prealbumin, vitamin levels in malnourished patients
• Hypercoagulability workup if thrombosis is identified [6]

• First-line: Mesenteric duplex ultrasound with respiratory maneuvers (inspiration and expiration) — recommended initial diagnostic modality [9][15]
  • Celiac artery peak systolic velocity (PSV) >200 cm/s during expiration; end-diastolic velocity ≥350 cm/s with deflection angle ≥50° has 83% sensitivity and 100% specificity [2]
  • Velocities normalize with deep inspiration (pathognomonic dynamic finding)
• Confirmatory: CT angiography (CTA) with 3D reconstruction — demonstrates the characteristic "J-hook" or "hook sign" of the celiac artery, focal proximal narrowing, and poststenotic dilatation [9][12-13]
  • [12]
• Alternatives: MR angiography (useful in contrast allergy); lateral mesenteric angiography with breathing maneuvers is the criterion standard [2]
• When imaging is unnecessary: Incidental celiac compression on CT without symptoms does not warrant further workup — asymptomatic celiac compression is found in ~7–21% of the population [2]

• Celiac plexus block (percutaneous): Performed preoperatively in ~75–78% of surgical candidates; a positive response (pain relief) may predict favorable surgical outcome [3][8]
• Gastric exercise tonometry: Elevated gastric-arterial PCO₂ gradient after exercise suggests gastric ischemia; used in some centers for diagnosis and postoperative follow-up [2]
• Provocative mesenteric angiography: Performed in 12–36% of patients; demonstrates dynamic compression with respiratory maneuvers [8]
• Intraoperative duplex ultrasound: Used during surgery to confirm adequate celiac artery decompression [2]
• No validated clinical scoring system exists for MALS

• ECG is not directly relevant to MALS diagnosis
• Obtain ECG if acute abdominal pain presentation to rule out inferior MI (which can mimic epigastric pain)
• Consider ECG if dysautonomia or POTS is suspected as a comorbidity [9]

MALS is a rare, controversial diagnosis of exclusion characterized by chronic postprandial epigastric pain, nausea, vomiting, and weight loss due to celiac artery compression by the median arcuate ligament. [1-2] The pathophysiology involves both vascular (foregut ischemia) and neuropathic (celiac ganglion compression) components. [2] Diagnosis is typically delayed by months to years. Asymptomatic celiac compression is common (7–21% of the population), making clinical correlation essential. [2]

• Severity stratification: Degree of celiac stenosis (grade I–IV), weight loss severity, nutritional status, and response to celiac plexus block
• Atypical presentations: Constant (non-postprandial) pain, exercise-induced pain only, concurrent vascular compression syndromes
• Complications: Celiac artery thrombosis, chronic malnutrition, functional GI disorders, opioid dependence [6]

Initial/Conservative Management

• Small, frequent, low-fat meals; nutritional optimization [10]
• Analgesics, antiemetics, PPI trial
• Celiac plexus block for diagnostic and therapeutic purposes [2][8]
• Multidisciplinary evaluation (gastroenterology, vascular surgery, pain management, psychology) [9]

Definitive Treatment — Surgical Decompression

• Median arcuate ligament release (MALR) ± celiac ganglionectomy ± revascularization [1-2]
• Approaches:
  • Laparoscopic: Shorter hospital stay (1.7 ± 1.3 days), lower morbidity, 4.3–4.6% conversion rate; symptom improvement in 71.5–88.7% [3][8]
  • Open: Greater pain improvement (84.2% vs. 71.5%) and nausea improvement (89.7% vs. 78.5%), but longer hospital stay (4.6 ± 1.7 days) and higher ileus rate (17.5%) [8]
  • Robotic: Increasingly used; comparable outcomes to laparoscopic [5]
• Overall surgical success rate: 70–85% [9][11]
• Recurrence: Symptom recurrence in up to 45%, often within 3 months, frequently without radiographic correlate [3]
• Adjunctive procedures: Angioplasty/stenting for recalcitrant cases or fixed stenosis; vascular reconstruction (patch angioplasty, aortoceliac bypass) for chronic intimal damage [2][11]

• Admission criteria: Acute mesenteric ischemia, celiac thrombosis, hemodynamic instability, severe malnutrition requiring nutritional support, postoperative monitoring
• Discharge criteria (postoperative): Tolerating oral intake, pain controlled, no surgical complications; median hospital stay is 2–3.5 days for laparoscopic, 4–5 days for open [3-4][8]
• Observation: Patients with equivocal diagnosis awaiting celiac plexus block results or further imaging
• Specialist consultation triggers: Vascular surgery (definitive management), gastroenterology (exclusion of other diagnoses), interventional radiology (celiac plexus block, angiography), pain management, psychology/psychiatry [9]

• Postoperative follow-up: Duplex ultrasound at 1–3 months to assess celiac artery flow; repeat imaging if symptoms recur [2][9]
• Symptoms requiring immediate reassessment: Acute severe abdominal pain, hematemesis, melena, fever, signs of peritonitis
• Expected recovery: Most patients report initial symptom improvement within weeks; however, up to 45% may experience recurrence [3]
• Persistent symptoms postoperatively: Re-evaluate for residual celiac stenosis (may need revascularization), celiac plexus block if flow is normalized, or consider functional GI disorder requiring medical management [9]
• Patient counseling: MALS is a complex condition; surgical success is 70–85% but not guaranteed; psychiatric comorbidities and MCAS may predict poorer outcomes; long-term follow-up data beyond 5 years are limited [1][9][14]

1. Median Arcuate Ligament Syndrome. — Goodall R, Langridge B, Onida S, et al. Journal of Vascular Surgery. 2020.

2. Median Arcuate Ligament Syndrome—Review of This Rare Disease. — Kim EN, Lamb K, Relles D, et al. JAMA Surgery. 2016.

3. Minimally Invasive Surgery for Median Arcuate Ligament Syndrome: Clinical Outcomes and Recurrence Patterns. — Boaz E, Aeschbacher P, Okida F, et al. Surgery. 2026.

4. A Diagnostic Workup and Laparoscopic Approach for Median Arcuate Ligament Syndrome. — Diab J, Diab V, Berney CR. ANZ Journal of Surgery. 2022.

5. Short and Longterm Outcome of Minimally Invasive Therapy of Median Arcuate Ligament Syndrome. — Butz F, Haase O, Martin F, et al. Langenbeck's Archives of Surgery. 2024.

6. Celiac Trunk Thrombosis in a Patient With Antiphospholipid Syndrome Induced by Median Arcuate Ligament Compression: A Case Presentation and Literature Review. — Janiak P, Smoleńska Ż, Skotarczak M, Zdrojewski Z. Rheumatology International. 2024.

7. Abdominal Compression Syndromes in the Hypermobile Ehlers-Danlos Syndrome. — Milunsky A, Milunsky JM, Hsu R. American Journal of Medical Genetics. Part A. 2025.

8. Balancing Operative Risk and Symptom Relief: Outcomes of Open Versus Laparoscopic Release for Median Arcuate Ligament Syndrome: A Retrospective Study. — Alsabbagh Y, Erben Y, Lanka SP, et al. Journal of Vascular Surgery. 2026.

9. Median Arcuate Ligament Syndrome - Current State of Management. — Skelly CL, Mak GZ. Seminars in Pediatric Surgery. 2021.

10. ACR Appropriateness Criteria® Radiologic Management of Mesenteric Ischemia: 2022 Update. — Expert Panel on Interventional Radiology, Lam A, Kim YJ, et al. Journal of the American College of Radiology : JACR. 2022.

11. Open Surgical Decompression and Revascularization of the Celiac Axis for Median Arcuate Ligament Syndrome in the Modern Era of Minimally Invasive Surgery. — West CA, Vieira EJ, Crawford JL, et al. Annals of Vascular Surgery. 2025.

12. Utility of Hook Sign in the Diagnosis of Median Arcuate Ligament Syndrome. — Chan SM, Weininger G, Kozhimala M, et al. Annals of Vascular Surgery. 2023.

13. Median Arcuate Ligament Syndrome: Evaluation With CT Angiography. — Horton KM, Talamini MA, Fishman EK. Radiographics : A Review Publication of the Radiological Society of North America, Inc. 2005.

14. Prognostic Factors for the Long Term Outcome After Surgical Celiac Artery Decompression in MALS. — Woestemeier A, Semaan A, Block A, et al. Orphanet Journal of Rare Diseases. 2023.

15. Median Arcuate Ligament Syndrome: The Past and the Future. — Ratnasamy K, Sanghavi R. Gastroenterology Clinics of North America. 2025.

16. Median Arcuate Ligament Syndrome With Concomitant Hyperkinetic Gallbladder. — Hardy JT, Brandeis BO, Shiva A, Kavic SM, Nagarsheth K. The American Surgeon. 2025.