Median Arcuate Ligament Syndrome - An Overview

What Is Median Arcuate Ligament Syndrome?

The disorder known as median arcuate ligament syndrome (MALS) is marked by an excessive amount of pressure exerted by the median arcuate ligament on the celiac artery (a small blood vessel that comes from the aorta just before it enters the belly/ abdomen) and both the local nerves (celiac plexus) and the aorta (which feeds blood into the intestines, liver function, and countless other organs). The bands of tissue known as ligaments are responsible for connecting one cartilage or bony structure to another. The connection between the diaphragm and the spine is made by the median arcuate ligament, which has an arch shape and wraps itself across the aorta (the artery within the heart that supplies blood to the rest of the body).

What Causes the Condition to Occur?

In an individual in MALS, the median arcuate ligament effectively functions as a hammer, compressing the take-off of main vessels and squeezing nerves in between. MAL cuts off the blood supply to the stomach and the liver by constricting the artery just before it branches, often the reason for patients' complaints of post-meal discomfort. Median arcuate ligament syndrome (MALS) differs from median arcuate ligament compression (MALCC).

What Are the Symptoms?

An ache throughout the upper abdomen following a meal is the first symptom of MALS. The following are some more signs that may be present:

• Weight loss (sometimes exceeding twenty pounds) results from the pain, making one avoid food (a condition known as food aversion).

• Nausea.

• Diarrhea.

• A delay in food transiting from the digestive tract to the small intestine (delayed gastric emptying).

• A vascular blockage may occur if a clinician occasionally hears a faint whooshing while placing a stethoscope (bruit) over the upper abdomen.

• Some patients, such as athletes, might develop recurrent upper abdominal pain when engaging in moderate to vigorous cardiovascular exercise.

• Chest pain, palpitations (hearing or feeling a racing heartbeat), diarrhea, constipation, and trouble sleeping are symptoms that are related to the diagnosis but frequently point to other health issues.

What Are the Causes of the Condition?

The diaphragm's right and left connections combine as they cross an aorta to reach the abdominal cavity into the chest to form the median arcuate ligament. Compression depends on the closeness of the ligament to the origin of the celiac artery:

• Compression may occur for branches off from the aorta beyond the diaphragm.

• Generally, there is no compression if it branches below a diaphragm.

  • Celiac Artery Compression - Celiac artery compression, celiac nerve plexus compression, or a combination of both may be to blame for the symptoms' inadequate blood flow or irritation of the nerves.

  • Steal Phenomenon - When a patient ingests, compression within the celiac artery may cause blood flow to originate from a separate gastrointestinal blood vessel (the superior mesenteric artery) and travel to the heart, the liver, and the stomach, leading to aches.

  • Overstimulated Peri Aortic Ganglia and Celiac Nerve Plexus - The peri-aortic ganglia and celiac nerve plexus, which are located near the celiac artery, are overstimulated, causing the arteries leading to the stomach and small bowel to spasm, which causes symptoms.

  • The Neurological Aspect- The compression of the nerves interferes with the pain pathways between the brain and stomach (neuro-enteric), causing hypersensitivity and discomfort in the stomach. Common surgical wisdom maintains that two of the three primary intestine blood arteries must be blocked for persistent gastrointestinal ischemia to occur; however, many medical professionals infer that gastrointestinal ischemia may have various reasons, including a neurologic component.

What Are the Diagnostic Methods?

MALS typically presents symptoms similar to those of stomach illnesses.

• Lab Testing - These tests look for liver, pancreatic, kidney, and other disorders. White and red blood cell counts exhibit levels; a high white blood cell count may indicate an infection.

• Duplex Ultrasonography - Due to the absence of ionizing radiation and the requirement for contrast, duplex ultrasonography can be a useful technique for the first screening patients suspected of having celiac artery compression. It requires an experienced operator to examine and demonstrate the modifications. In addition, it is constrained by the regularity of the individual's body and the gas present above the intestines. It can demonstrate the reduction in diameter following stenosis and the acceleration that becomes particularly evident during inhalation.

• CTA - Computed tomography angiography (CTA) helps diagnose since it allows for the three-dimensional visualization of a compressed celiac artery. CTA has a high degree of detail and can detect changes, including post-stenotic dilatation (vessel wall narrowing). However, it requires ionizing radiation, which can be a limitation for individuals with compromised immune systems.

• MRA - Patients who have an allergy to intravenous contrast agents may be able to benefit from magnetic resonance angiography (MRA), which is a type of alternative modality.

• Angiography - In certain cases, lateral mesenteric angiography may be the most effective method for evaluating both the anatomy and the dynamic alterations that have taken place. Compression of the celiac artery and post-stenotic dilatation on expiration can be identified by a cephalic displacement of the celiac axis that occurs during expiration. Angiograms combined with certain breathing exercises can often greatly assist in making a diagnosis. It is possible to observe compression of the celiac artery during expiration, along with the development of related collaterals resulting from the compression.

What Are the Treatment Methods?

The goal of the treatment for MALS is to decompress the celiac artery so that there is an appropriate flow of blood and to regulate the pain experienced by the individual by using neurolysis.

1. Surgical Treatment:

• Open Decompression: It was traditionally considered to be the first option available. During this procedure, the surgeon would remove the diaphragmatic crura (one of two structures of tendons that go from the diaphragm to the spinal column.) from the celiac axis. The neuropathic pain that is associated with MALS can be treated by removing the ganglion and revascularization of the celiac artery.

• Interventional Radiology - The use of interventional radiology in treating MALS is increasingly common, as well as the utilization of medical imaging modalities to assist physicians in diagnosing and treating specific disorders affecting the lymphatic and blood vessels of the body.

2. Adjuvant Therapies

• Percutaneous Transluminal Angioplasty (PTA) - It is a form of treatment that can be administered before surgical intervention. PTA may play a part in preventing post-surgical recurrence in some cases. Patients with symptoms following surgery may benefit from PTA combined with balloon expandable stents because it can be used as an adjuvant treatment.

• Laparoscopic Surgery - A surgical procedure wherein tiny (less than one centimeter) incisions introduce short, narrow tubes into the belly. The arcuate ligament is relaxed through this procedure, while intraoperative duplex ultrasonography is utilized. The laparoscopic procedure has several benefits, including a smaller incision, a lower risk of complications, and an improved view during surgery.

• Vascular Reconstruction - There is a possibility that individuals diagnosed with MALS will require open surgery to fix or repair an obstructed celiac artery. If vascular reconstruction is used as a treatment choice is either not feasible or does not alleviate the symptoms, vascular reconstruction would be considered. Vascular reconstruction: it reconstructs broken blood vessels and restores blood flow using synthetic grafts or blood vessels from other body parts.

Conclusion

The condition known as median arcuate ligament syndrome (MALS) is brought on by the compression of an artery that provides blood to the upper abdomen by an arc-shaped band of the tissue in the thorax known as the median arcuate ligament. MALS can induce abdominal pain in some individuals and is an uncommon condition that is diagnosed by exclusion. The diagnosis is challenging and requires a high level of suspicion and imaging findings supporting the diagnosis. There are various treatment options to manage the condition, and prompt and accurate treatment helps patients to relieve the condition.