What Is Median Arcuate Ligament Syndrome?

Overview

Median arcuate ligament syndrome (MALS), also known as celiac artery compression syndrome, is an uncommon condition caused by the pressure of the celiac artery by low riding of fibrous connections of the middle arcuate tendon and diaphragmatic crura.¹ MALS is frequently hard to diagnose because of the vague symptoms of weight loss, abdominal pain, and early satiety. This article aims to comprehensively overview MALS, including its causes, symptoms, diagnosis, and treatment options.

Causes of MALS

The median arcuate ligament is a band of fibrous tissue that connects to the diaphragmatic crura (tendons that support the diaphragm), which are found around the aortic hiatus (an opening in the diaphragm where the aorta passes).¹ Its job is to support and stabilize the celiac artery, which supplies blood to the stomach, liver, spleen, and other upper abdominal organs. Typically, the ligament runs across the largest blood vessel in the body (aorta) and sits over the celiac artery. The higher origin of the celiac artery or lower insertion of diaphragmatic crura will likely lead to MALS.¹ 

The exact cause of MALS is not always clear. However, several factors may contribute to its development. The lower abdominal aorta occasionally becomes compressed when the median arcuate ligament crosses it. The celiac axis and other vasculature frequently shift upward during expiration, increasing compression.¹ This vascular compression impairs blood flow, which causes a variety of MALS symptoms and complications.²

In addition, anatomical changes might worsen the narrowing of the celiac artery, resulting in MALS, such as a low-lying or more fibrous median arcuate ligament, fibromuscular dysplasia, or atherosclerosis.^3,4 

Signs and symptoms of MALS

MALS patients occasionally show no symptoms. Moreover, since MALS symptoms can vary in severity and resemble those of other gastrointestinal disorders, a precise diagnosis might be challenging to make. Typical symptoms of MALS include

• Abdominal pain: The most common symptom in the upper abdomen is pain that may worsen after eating or during physical activity
• Weight Loss: Unexplained weight loss may occur due to a decreased blood supply to the digestive organs. Symptoms are typically most severe following rapid weight loss
• Nausea and Vomiting: Food digestion issues might result in nausea and occasional vomiting
• Postprandial Distress: Discomfort and bloating may result from symptoms that develop after meals
• Epigastric Bruit: A whooshing sound called an epigastric bruit, may be heard over the abdomen with a stethoscope
• Malnutrition: Prolonged MALS can affect nutrient absorption, which may lead to malnutrition and vitamin deficiencies

Diagnosis

Several diagnostic tools may be used including:⁵ 

• Doppler ultrasound: Enables real-time viewing of blood flow to detect abnormalities in the celiac artery
• Computed Tomography Angiography (CTA): Help diagnose compression using detailed images of the celiac artery and its surroundings
• Magnetic Resonance Angiography (MRA): Allows doctors and scientists to see inside the blood vessels to spot any potential compression
• Digital Subtraction Angiography (DSA): An invasive procedure involving breathing manoeuvres used to monitor the blood pressure and flow rates in the celiac artery

Management and treatment options for MALS

The treatment choice for MALS depends on the severity of symptoms and the patient’s overall health. Treatment options include⁶

• Conservative management: Mild instances may improve with lifestyle measures such as dietary adjustments and weight control
• Medication: Medications that control pain and ease stomach discomfort can provide symptomatic relief
• Interventional Procedures: The celiac artery can be widened, and blood flow improved with minimally invasive procedures, including angioplasty and stent implantation
• Surgical Intervention: Surgery may be required to decompress the compressed artery and relieve symptoms in severe cases or when other therapies fail to work

FAQs

How common is MALS?

MALS is a rare disease found in 2 out of 100,000 patients. The typical symptoms include stomach pain, nausea, and unexpected weight loss.¹

Who is at risk of MALS?

MALS can affect anyone at any age, but it is more frequently found in females with thin bodies between 20-40 (observed female: male predominance of 4:1). The exact reason women are more likely to develop MALS is not fully understood. However, a few things have been suggested as contributing risk factors in women:⁷

• Anatomical differences: Women may have a higher prevalence of anatomical changes than men, which can cause the celiac artery to become compressed. These could include the diaphragmatic crura’s lower insertion or the celiac artery’s higher origin
• Hormonal factors: Hormonal changes in women can impact blood flow and vascular function, notably during menstruation and pregnancy. In some situations, these hormonal changes may aid in the onset or progression of MALS
• Body composition: MALS has been discovered to be more common in slender female body types. Lower body fat and a more restricted passageway for the celiac artery are thought to enhance the risk of compression
• Connective tissue differences: The characteristics of women’s connective tissues may differ from men’s in specific ways, which may impact the development of MALS
• Diagnostic Bias: MALS might be more frequently recorded in women with abdominal pain or gastrointestinal symptoms than men, resulting in higher reported cases in females

It is crucial to note that the understanding of MALS and its risk factors may evolve, and if you have concerns, you should seek advice from professionals regardless of gender.

How is MALS diagnosed?

Diagnosing MALS is a multi-step process that involves eliminating other potential illnesses that could have similar symptoms, i.e., abdominal disorders. A thorough medical history, physical examination, and discussion of symptoms are essential in guiding the diagnostic process. Since MALS can mimic abdominal disorders, it can lead to potential delays in diagnosis and treatment, as other conditions are explored first. Your doctor can accurately diagnose MALS using a combination of clinical evaluation and imaging results. If you think you could have MALS or are exhibiting alarming symptoms, seek advice from a trained healthcare professional for an accurate evaluation and diagnosis is crucial. Early diagnosis and appropriate management can improve outcomes and MALS-related symptom reduction.¹

What is the best treatment option for MALS?

MALS patients may experience instant relief via minimally invasive surgery, which means smaller incisions and shorter hospital stays. During the surgery, an object to release pressure on the blood vessel will be implanted after making a few tiny incisions using a catheter to access the median arcuate ligament. To get the best results, open surgery could be necessary for some patients. You should discuss all options with your doctor to choose the best approach.

What to expect from the surgery? 

The laparoscopic approach will be used to complete the operation. There will be five to six abdominal laparoscopic incisions performed. A second duplex ultrasound will be performed in the operating room after the median arcuate ligament has been loosened to ensure the blood flow has returned to normal. The procedure is finished when the surgeon has observed that the blood flow has returned to normal.

What aftercare is essential post surgery?

• A glossy material called Dermabond will cover the laparoscopic sites. Within a few days of the procedure, you will be given permission to bathe. However, the Dermabond covering the incisions should not be scrubbed off or removed. The Dermabond will disappear on its own in a few weeks
• Before your doctor gives the all-clear, you should refrain from engaging in intense activities, sports, or heavy lifting
• You can follow a regular diet, although you are advised to consume several little meals throughout the day rather than a few large ones. Postoperative constipation is typical. The use of anaesthetics and painkillers may cause constipation. You should drink enough  water and avoid alcoholic and caffeinated beverages
• It is crucial to take the painkillers precisely as the surgeon has instructed. You should speak with your doctor if the pain is not under control

How can I prevent MALS?

There is no specific way to prevent MALS since the exact cause is still unclear. However, certain lifestyle choices can maintain vascular health and lower the chance of developing vascular conditions like MALS; they include:

• Maintaining a healthy diet
• Exercising regularly 
• Avoiding smoking and alcohol consumption
• Managing stress
• Regular health check-ups

When should I see a doctor?

You should consider a consultation with a doctor if you experience the following:

1. Persistent abdominal pain
2. Unexplained weight loss
3. Severe nausea/vomiting
4. Early satiety
5. Bloating and digestive issues

If you suspect that you may be developing these symptoms, it is essential to seek a medical approach promptly. Do not hesitate to schedule an appointment with your doctor or a specialist, such as a gastroenterologist or vascular surgeon, for proper evaluation and management. Early diagnosis and appropriate management can help prevent potential complications.

Summary

Median Arcuate Ligament Syndrome (MALS) is a rare illness caused by the pressure of the celiac artery due to fibrous connections between the middle arcuate tendon and diaphragmatic crura. It has vague symptoms that make diagnosis challenging, such as early satiety, stomach pain, and sudden weight loss. Females between 20 and 40 are more likely to develop MALS. Causes of this disease may involve anatomical changes or vascular shifts during expiration that compress the celiac artery, impairing blood flow and causing various symptoms. Imaging procedures, including duplex ultrasonography, CTA, MRA, or traditional angiography, are employed in the diagnosis to rule out other diseases. Depending on the severity of the symptoms, treatment options include conservative care, drugs, intervention, or surgery. Maintaining a healthy lifestyle can help promote vascular health; however, there is no specific way to prevent MALS. It is critical to get medical assistance right away when experiencing symptoms like abdominal pain, weight loss, or nausea to be adequately assessed and managed by medical professionals before it gets fatal.