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In medicine, the median arcuate ligament syndrome (MALS, also known as celiac artery compression syndrome, celiac axis syndrome, celiac trunk compression syndrome or Dunbar syndrome) is a condition characterized by abdominal pain attributed to compression of the celiac artery and possibly the celiac ganglia by the median arcuate ligament. The abdominal pain may be related to meals, may be accompanied by weight loss, and may be associated with an abdominal bruit heard by a clinician. It is also called ''celiac artery compression syndrome''. The diagnosis of MALS is one of exclusion, as many healthy patients demonstrate some degree of celiac artery compression in the absence of symptoms. Consequently, a diagnosis of MALS is typically only entertained after more common conditions have been ruled out. Once suspected, screening for MALS can be done with ultrasonography and confirmed with computed tomography (CT) or magnetic resonance (MR) angiography. Treatment is generally surgical, the mainstay being open division, or separation, of the median arcuate ligament combined with removal of the celiac ganglia. The majority of patients benefit from surgical intervention. Poorer responses to treatment tend to occur in patients of older age, those with a psychiatric condition or who use alcohol, have abdominal pain unrelated to meals, or who have not experienced weight loss. ==Anatomy and pathogenesis== Side views (sagittal plane) of the descending aorta and two of its branches, the celiac trunk and superior mesenteric artery, demonstrate normal and MALS anatomy. ''Left'' The median arcuate ligament is normally several millimeters to centimeters superior to the origin of the celiac artery. ''Right'' In MALS, the ligament is anterior, rather than superior, to the celiac artery, resulting in compression of the vessel and a characteristic hook-shaped contour. The median arcuate ligament is a ligament formed at the base of the diaphragm where the left and right diaphragmatic crura join near the 12th thoracic vertebra. This fibrous arch forms the anterior aspect of the aortic hiatus, through which the aorta, thoracic duct, and azygos vein pass. The median arcuate ligament usually comes into contact with the aorta above the branch point of the celiac artery. However, in up to one quarter of normal individuals, the median arcuate ligament passes in front of the celiac artery, compressing the celiac artery and nearby structures such as the celiac ganglia.〔 In some of these individuals, this compression is pathologic and leads to the median arcuate ligament syndrome.〔 Several theories attempt to explain the origin of pain caused by compression of the celiac artery.〔 One proposes that compression of the celiac artery causes ischemia, or decreased blood flow, to abdominal organs, leading to pain. Another hypothesizes that there is compression not only of the celiac artery but also of the celiac ganglia, and that pain results from compression of the latter. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Median arcuate ligament syndrome」の詳細全文を読む スポンサード リンク
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