Median Arcuate Ligament Syndrome (MALS)
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Overview
Median Arcuate Ligament Syndrome (MALS) is a condition where the median arcuate ligament, a fibrous band of the diaphragm, sits lower than normal and compresses:
- The celiac artery
- The celiac plexus (nerve bundle)
This compression reduces blood flow and irritates nerves, producing a combination of vascular symptoms and neuropathic pain.
Celiac artery compression syndrome is another name for MALS — the same condition, with the same mechanism and the same symptoms.
MALS is often misdiagnosed as:
- Functional abdominal pain
- IBS
- Gastritis
- Gallbladder disease
- Eating disorders
- Anxiety
- Post‑bariatric pain
- Chronic mesenteric ischemia
Because of this, patients frequently suffer for years before receiving a correct diagnosis.
Causes
- Low insertion of the median arcuate ligament
- Compression of the celiac artery
- Compression of the celiac plexus
- Respiratory variation (worse on exhalation)
- Chronic irritation of foregut nerves
- Reduced blood flow to foregut organs
- Congenital anatomical variation
Risk Factors
- Female sex (more common)
- Thin body habitus
- Congenital ligament position
- High diaphragmatic insertion
- Prior foregut surgery
- Chronic foregut inflammation
- Hypermobile connective tissue disorders (reported associations)
How It Affects the Body
MALS affects both blood flow and nerve signaling.
Vascular Effects
Compression of the celiac artery may reduce blood flow to:
- Stomach
- Liver
- Spleen
- Pancreas
- Proximal small intestine
This can cause:
- Post‑prandial pain
- Weight loss
- Food fear
- Fatigue
- Exercise intolerance
Neuropathic Effects
Compression of the celiac plexus can cause:
- Burning pain
- Radiating pain to the back or flank
- Nausea
- Vomiting
- Early satiety
- Autonomic symptoms
This dual mechanism is why MALS symptoms are often severe and difficult to classify.
Complications
- Severe weight loss
- Malnutrition
- Chronic abdominal pain
- Food avoidance
- Reduced quality of life
- Anxiety related to eating
- Secondary foregut dysfunction
- Collateral vessel formation
- Rare aneurysm formation in collateral arteries
Symptoms and Signs
MALS symptoms vary but often include:
- Severe abdominal pain, especially after eating
- Pain in the upper abdomen, epigastrium, or left upper quadrant
- Pain radiating to the back or flank
- Nausea
- Vomiting
- Early fullness
- Unintentional weight loss
- Food fear
- Exercise‑induced pain
- Bloating
- Fatigue
- Diaphragmatic pain
- Symptoms worse on exhalation
Patients often describe:
- “A deep, pressure‑like pain under the ribs.”
- “Pain that feels like it’s coming from behind the stomach.”
- “Pain that gets worse after eating even small meals.”
Diagnosis
Accurate diagnosis requires specialized testing:
1. CT Angiography (CTA)
Shows celiac artery narrowing and respiratory variation.
2. Doppler Ultrasound
Evaluates blood flow velocity changes with breathing.
3. MR Angiography (MRA)
Assesses vascular anatomy and compression.
4. Endoscopy
Rules out ulcers, gastritis, or other foregut pathology.
5. Clinical Evaluation
Symptom pattern recognition is essential.
Differential Diagnosis
- Chronic mesenteric ischemia
- Gastroparesis
- GERD
- Hiatal hernia
- Gallbladder disease
- Pancreatitis
- SMA syndrome
- Functional abdominal pain
- IBS
- Gastritis
- Ulcers
- Post‑bariatric pain syndromes
Lifestyle Modifications
Lifestyle changes do not cure MALS but may reduce symptom severity:
- Smaller meals
- Avoid large, heavy meals
- Avoid lying down after eating
- Hydration
- Gentle activity
- Avoid high‑fat meals
- Stress reduction
- Breathing techniques (symptom modulation)
Treatment Options
Non‑Surgical
- Nutrition support
- Symptom monitoring
- Pain management
- Evaluation for contributing foregut conditions
Endoscopic
Used to rule out or treat:
- Ulcers
- Gastritis
- Strictures
- Sleeve‑related issues
- Foregut inflammation
Surgical (Definitive Treatment)
Median Arcuate Ligament Release
- Removes compression on the celiac artery
- Frees the celiac plexus
- Restores blood flow
- Reduces nerve irritation
Celiac Plexus Neurolysis
- Reduces neuropathic pain
- Often performed during ligament release
Vascular Reconstruction (select cases)
- For severe arterial narrowing
- For aneurysm risk
- For persistent stenosis after decompression
Dr. de la Cruz-Muñoz performs:
- Minimally invasive MALS release
- Robotic MALS release
- Combined foregut + vascular evaluation
- Complex revision cases
- Treatment of patients previously misdiagnosed
When to See a Doctor
Seek evaluation if you experience chronic upper abdominal pain, especially after meals, or unexplained weight loss.
When to Seek Treatment
Seek evaluation if:
- You have severe post‑prandial pain
- You have pain radiating to the back or flank
- You have unexplained weight loss
- You have early fullness
- You have nausea or vomiting after meals
- You have been told “everything is normal” but still have symptoms
- You have symptoms worse on exhalation
- You have been evaluated for years without answers
Long‑Term Outlook
Most patients regain:
- Normal eating
- Weight stability
- Improved energy
- Reduced pain
- Better quality of life
Some patients require:
- Ongoing foregut evaluation
- Pain modulation strategies
- Vascular follow‑up
- Nutritional support
Related Reading and Videos
Read more in our articles What Actually Happens in the Operating Room During My Surgery?. Watch What Actually Happens in the Operating Room During My Surgery? on our video library. Related conditions include SMA Syndrome (Superior Mesenteric Artery Syndrome), Celiac Plexus Neuralgia and Nutcracker Syndrome. Treatments that may be involved include Median Arcuate Ligament Release (MALS Surgery), Foregut Surgery and Robotic Surgery.
Prognosis
Many patients experience significant improvement after surgical decompression. Outcomes depend on:
- Degree of compression
- Duration of symptoms
- Presence of neuropathic pain
- Collateral vessel formation
- Overall foregut health
Early diagnosis improves long‑term results
Why Choose Dr. de la Cruz‑Muñoz
Dr. de la Cruz‑Muñoz is one of Florida’s most experienced surgeons in diagnosing and treating MALS and celiac artery compression.He is widely recognized for:
- High‑volume MALS surgery
- Expertise in foregut + vascular anatomy
- Advanced minimally invasive and robotic techniques
- Successful treatment of complex and previously misdiagnosed cases
- Comprehensive evaluation of foregut pain syndromes
- Collaborative care with vascular specialists when needed
Patients travel from across the state — and often out of state — for his expertise.
Patients with MALS benefit from a surgeon at home in the upper abdomen. Dr. de la Cruz-Muñoz has completed over 15,000 minimally invasive procedures across over 25 years, spanning complex foregut, hernia, gallbladder and abdominal surgery as well as bariatric surgery.
Featured Procedures
FAQ
MALS occurs when the median arcuate ligament — a fibrous band of the diaphragm — presses on the celiac artery and the nerves around it (the celiac plexus) that supply the stomach and upper intestine (Kim et al., JAMA Surgery, 2016). The compression worsens when you breathe out and is aggravated by the increased blood-flow demand of digestion, producing pain, nausea, and vomiting after meals; over time, fear of eating leads to significant unintentional weight loss (Cernigliaro et al., Abdominal Radiology, 2021; Park et al., Vascular Medicine, 2025).
Yes, and it's more common than many doctors realize. Both conditions involve compression by the major arteries coming off the aorta. MALS often causes significant weight loss, which can then trigger SMA syndrome.
- Lozano et al.: in a series of 100 MALS operations, 19% of patients developed SMA syndrome (Lozano et al., Surgical Endoscopy, 2026).
- Sandmann et al.: another group reported that 31% of MALS patients later developed SMA syndrome requiring surgery (Lozano et al., Surgical Endoscopy, 2026).
- Why it matters: missing one diagnosis may explain why some patients don't improve after treatment of the other.
MALS is a diagnosis of exclusion — gallbladder disease, ulcers, reflux, pancreatitis, and motility disorders must be ruled out first (Kim et al., JAMA Surgery, 2016; Brenner et al., Clinical Gastroenterology and Hepatology, 2023). Diagnosis matches characteristic symptoms with imaging: CT/MR angiography showing the "hook sign" and post-stenotic dilation (worse on expiration), plus dynamic duplex ultrasound showing elevated celiac velocities (Koshy et al., Abdominal Radiology, 2024). A celiac plexus block that relieves symptoms supports the diagnosis and predicts a better surgical result (Shnayder-Adams et al., Journal of Vascular and Interventional Radiology, 2024).
Most appropriately selected patients improve — roughly 83–89% report partial or complete relief after release (Pather et al., Journal of Vascular Surgery, 2021; Boaz et al., Surgery, 2026). However, relief is not always permanent: estimated 5-year freedom from symptoms is about 67%, and recurrence (sometimes within the first three months) does occur (Pather et al., Journal of Vascular Surgery, 2021; DeCarlo et al., Journal of Vascular Surgery, 2023). Even so, about 87% of patients say they would undergo the operation again (Pather et al., Journal of Vascular Surgery, 2021).
Minimally invasive release produces the same long-term symptom relief as open surgery but with far lower complication rates, less ileus, and a shorter hospital stay (about 1.7 vs 4.6 days) (DeCarlo et al., Journal of Vascular Surgery, 2023; Alsabbagh et al., Journal of Vascular Surgery, 2026). Because the operation involves delicate dissection around the aorta and celiac artery, it is recommended that it be done by surgeons who focus on this disease (Park et al., Vascular Medicine, 2025) — the rationale behind a dedicated regional MALS program led by one of the first surgeons in Florida, if not the first, to perform this release minimally invasively.
Yes. Median arcuate ligament syndrome (MALS), celiac artery compression syndrome and Dunbar syndrome are names for the same condition. A fibrous band of the diaphragm — the median arcuate ligament — presses on the celiac artery and the surrounding celiac nerve plexus, causing pain after eating, weight loss and sometimes nausea. Diagnosis usually involves a CT angiogram or duplex ultrasound performed during deep breathing in and out, along with ruling out other causes. Treatment, when appropriate, is laparoscopic or robotic release of the ligament and nerve tissue.
For many patients, yes. Laparoscopic or robotic release of the median arcuate ligament and the surrounding celiac nerve fibers relieves symptoms in most carefully selected patients, though not all. Results are best when the diagnosis is confirmed with imaging, other causes of abdominal pain have been excluded, and symptoms clearly relate to eating. A minority of patients have persistent symptoms and may need additional evaluation or treatment of the celiac artery itself. Because the condition is uncommon and often misdiagnosed, evaluation by a surgeon experienced with MALS is important.
Celiac plexus neuralgia is chronic upper abdominal pain arising from the celiac plexus, a network of nerves around the celiac artery that carries pain signals from the upper abdominal organs. The nerves can be irritated or compressed — most notably by the median arcuate ligament in MALS — or affected by pancreatitis or prior surgery. Pain is often worse after eating and may be accompanied by nausea and weight loss. Treatment depends on the cause and may include nerve blocks or surgical release.
The standard treatment is laparoscopic or robotic release of the median arcuate ligament, dividing the fibrous band that compresses the celiac artery and removing the surrounding celiac nerve fibers that generate pain. Most carefully selected patients improve. A celiac plexus nerve block before surgery can help predict who is likely to benefit. If the artery remains narrowed after release, a vascular procedure may occasionally be needed. Nutritional support is important for patients who have lost significant weight.
