Clinical anatomy of median arcuate ligament syndrome: Unveiling the morphology and morphometry of median arcuate ligament, celiac trunk, and superior mesenteric artery, a radio anatomical study

Arthi Ganapathy1, Sudipta Mohakud2, Sipra Rout3, Praisy Joy3, Alamelu Alagappan2, Aarthi Manokaran3

1Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India; 2Department of Radiology, All India Institute of Medical Sciences, Bhubaneswar, India; 3Department of Anatomy, All India Institute of Medical Sciences, Bhubaneswar, India

Objective: Median arcuate ligament syndrome (MALS) is a rare condition where the celiac trunk (CT) is compressed by the median arcuate ligament (MAL). Owing to its vague presentation, accurate diagnosis of MALS poses challenge and there is limited literature on the anatomical relationship between MAL and CT.
Methods: This study conducted cadaveric dissections (n=11) and radiological analysis of 250 computed tomography angiograms to explore this relationship. Parameters examined included MAL, CT, and Superior mesenteric artery (SMA) vertebral levels, MAL thickness, distances between MAL, CT, and SMA, and CT/SMA diameter.
Results: Radiological analysis showed an average MAL thickness of 7.79 ± 2.58 mm. The CT originated at T12 level, with an average CT-MAL distance of 1.32 ± 2.04 mm. The angle between CT and abdominal aorta was mainly obtuse. Average CT diameter was 5.53 ± 1.33 mm. No significant association was found between presenting symptoms and measured radiological parameters. Histological examination of the MAL revealed a heterogeneous composition of loose connective tissue with variable collagen fiber density and the presence of skeletal muscle fibers suggesting varying mechanical properties and functions in different regions.
Conclusion: This study provides comprehensive morphometric data on the anatomical relationship between MAL and the CT aiding in the diagnosis and management of MALS. The observed variations in MAL thickness, CT origin and diameter, and their distances can serve as reference values for accurate radiological diagnosis of MALS.

Keywords: cadaveric study; celiac artery compression syndrome; histology; median arcuate ligament thickness; morphometric parameters; radiological analysis