Median Arcuate Ligament Syndrome: Evaluation with CT Angiography

Abstract

The median arcuate ligament is a fibrous arch that unites the diaphragmatic crura on either side of the aortic hiatus. The ligament usually passes superior to the origin of the celiac axis. However, in some people, the ligament inserts low and thus crosses the proximal portion of the celiac axis, causing compression and sometimes resulting in abdominal pain. The diagnosis of clinically significant celiac axis compression, referred to as median arcuate ligament syndrome, is traditionally made with conventional angiography; however, the condition can now be diagnosed with three-dimensional computed tomographic (CT) angiography. In patients with median arcuate ligament syndrome, CT angiograms demonstrate a characteristic focal narrowing in the proximal celiac axis. The focal narrowing has a characteristic hooked appearance, which can help distinguish this condition from other causes of celiac artery narrowing, such as atherosclerotic disease. Once the disorder has been diagnosed, surgery can be performed to relieve the compression. In some patients, the ligamentous constriction of the celiac axis causes vascular damage, which may require vascular reconstruction. CT angiography can play a role in the diagnosis of median arcuate ligament syndrome by demonstrating the characteristic focal narrowing of the celiac artery in patients presenting with the appropriate clinical symptoms.

Diagnosis of Median Arcuate Ligament Syndrome on Multidetector Computed Tomography

“…However, recent implementation of MDCT has enabled the production of fast, thin-slice, multiplanar, reformatted and 3D angiographic images. Also, high-resolution images can be obtained for the aorta and its branches and also for the mesenteric vascular structures [6]. In our study with 64-slice CT, the multiplanar reformatted 3D angiographic images perfectly demonstrated the vascular anatomy and compression without any need for conventional angiography, which is a more invasive technique.…”

“…This ligament may cause a compression and abdominal pain while passing anterior to the proximal part of the celiac truncus [6]. The MALS was initially described by Harjola, in 1963 [7].…”

“…In the cases with MALS, the celiac artery is narrowed by the MAL during expiration [5]. In inspiration, however, the celiac artery descends to the abdominal cavity, and compression is often relieved due to the more vertical orientation of the celiac artery [6]. Celiac, superior, and inferior mesenteric arteries are the fundamental vascular structures that supply the intestinal ansae, and there is a perfect collateral circulation among them.…”

“…Surgical treatment of MAL syndrome is performed in the ages between 40 and 60 in order to eliminate the symptoms such as postprandial abdominal pain, weight loss, poststenotic dilatation, and collateral vascular vessels [6]. The options of treatment for the MALS include surgical or laparoscopic division of the celiac ganglion destruction and ganglion blockage [10].…”

Median arcuate ligament syndrome

“…Clinically, they described a classical triad of chronic postprandial abdominal pain, epigastric bruit, and weight loss. 3,4 Extrinsic compression of the celiac trunk by the MAL occurs in 10% to 24% of patients. 1 Usually, patients are asymptomatic and the classical triad is not always present, presumably due to collateral supply from the superior mesenteric circulation.…”