MALS

MALS most commonly stands for Median Arcuate Ligament Syndrome, a rare vascular compression disorder in which the median arcuate ligament of the diaphragm compresses the proximal celiac axis (celiac trunk). The condition can lead to abdominal ischemia and pain, especially after meals, but it is characterized by clinical variability and a debated prevalence.

Symptoms typically include postprandial upper abdominal (epigastric) pain, early satiety, and weight loss. Some patients report nausea or back or chest discomfort. The pain may fluctuate with respiration, often worsening during expiration when the ligament's compression of the celiac artery increases. Because symptoms are nonspecific, MALS is a diagnosis of exclusion after other gastrointestinal and vascular causes are considered.

Pathophysiology involves anatomical variation where the diaphragmatic median arcuate ligament lies low or the celiac trunk arises atypically, causing dynamic compression of the celiac axis as the diaphragm moves. Chronic compression may contribute to mesenteric ischemia and irritation of the celiac plexus, though the exact mechanisms and the degree to which ischemia drives symptoms are subjects of ongoing study.

Diagnosis relies on imaging and clinical correlation. CT angiography or MR angiography can show focal compression of the celiac artery with a characteristic “hooked” appearance, often more evident during expiration. Doppler ultrasound can assess hemodynamic changes in the celiac axis. Angiography with provocative maneuvers is occasionally used. Diagnosis requires careful exclusion of other causes of postprandial pain and weight loss.

Treatment is usually surgical decompression to release the median arcuate ligament, performed laparoscopically, robotically, or openly. Some cases may involve neurolysis of the celiac plexus or, rarely, vascular reconstruction if arterial integrity is compromised. Prognosis varies; many patients experience symptom improvement after decompression, while others have persistent or recurrent symptoms. MALS is relatively rare and more frequently reported in young to middle-aged individuals, with a female predominance in some series. In other contexts, MALS can refer to different disorders, but this article focuses on Median Arcuate Ligament Syndrome.