Median Arcuate Ligament Syndrome (MALS)

Median arcuate ligament syndrome (MALS) is a rare medical condition characterized by the compression of the celiac trunk and/or the superior mesenteric artery by the median arcuate ligament (MAL). The MAL is a fibrous band that connects the diaphragm to the lumbar vertebrae, and in some individuals, it can compress the nearby blood vessels, leading to various symptoms.

Causes and Risk Factors

MALS is often associated with anatomical variations, such as a low-lying celiac trunk or an early takeoff of the superior mesenteric artery. Other potential causes include:

• Genetic predisposition
• Trauma or injury to the abdominal region
• Surgical procedures, such as laparoscopic cholecystectomy or gastric bypass surgery
• Congenital conditions, such as diaphragmatic eventration or malrotation of the gut

Symptoms

The symptoms of MALS can vary in severity and may include:

• Abdominal pain, often postprandial (after eating) or exacerbated by exercise
• Nausea and vomiting
• Weight loss
• Bloating and abdominal distension
• Dyspepsia (indigestion)
• Diarrhea or constipation

Diagnosis

The diagnosis of MALS can be challenging, as the symptoms are often non-specific and may resemble those of other conditions. Diagnostic tests that may be used to confirm MALS include:

• Duplex ultrasonography to evaluate blood flow in the celiac trunk and superior mesenteric artery
• Computed tomography (CT) angiography or magnetic resonance (MR) angiography to visualize the blood vessels and MAL
• Angiography to assess blood flow and pressure in the affected arteries

Treatment

Treatment for MALS typically involves a multidisciplinary approach, including:

• Surgical release of the MAL to relieve compression on the celiac trunk and/or superior mesenteric artery
• Minimally invasive procedures, such as laparoscopic or robotic surgery
• Open surgical repair in some cases
• Medical management, including pain control, dietary modifications, and management of related conditions (e.g., gastroesophageal reflux disease)

Prognosis and Complications

The prognosis for MALS is generally good with prompt diagnosis and treatment. However, if left untreated, MALS can lead to complications such as:

• Chronic abdominal pain and disability
• Malnutrition and weight loss due to reduced intestinal blood flow
• Gastrointestinal ischemia or infarction (tissue death due to lack of blood supply)