Median Arcuate Ligament Syndrome - Literature Review and Case Report.

INTRODUCTION: Median arcuate ligament syndrome (MALS) or Dunbar syndrome is a rare clinical entity characterized by celiac trunk compression by median arcuate ligament and variable gastrointestinal symptoms (postprandial epigastric pain, nausea, weight loss, anorexia and diarrhea). However, some degree of radiographic compression is observed in 10%-24% of asymptomatic patients. Besides the extrinsic vascular compression, MALS has a multifactorial etiology and it has been suggested as a neurogenic disease resulting in altered sensation and pain from the somatic nerves in the splanchnic plexus. MALS is a diagnosis of exclusion, so other causes must be excluded. Treatment options include release of median arcuate ligament (open, laparoscopic or robot-assisted) and open vascular reconstruction. Endovascular treatment is currently used only as adjuvant procedure after surgical approach, in refractory cases with residual stenosis of celiac trunk.

OBJECTIVE: To report a case of MALS and to review current literature.

METHODS: The authors report a clinical case and present a literature review using PubMed with the terms "median arcuate ligament", "Dunbar syndrome" and "MALS treatment" as major topics. The bibliography of relevant articles has been checked to identify other significant papers.

RESULTS: A 34-year-old woman, previously healthy, recurred to a General Practitioner with a recurrent epigastric pain, exacerbated by ingestion, without relieving factors, in the previous 6 months. Patient also reported anorexia and unprovoked weight loss of 8Kg over 3 months. Physical examination was normal. Other gastrointestinal pathologies were ruled out. Computed Tomography Angiography (CTA) abdomen revealed a focal 80% stenosis of the celiac trunk, located 8mm from its origin in aorta and a post- -stenotic enlargement of 9mm. An open decompression of the celiac trunk was performed. Through an 8cm median supraumbilical laparotomy, supraceliac abdominal aorta was approached. The compressive band across the celiac trunk was identified and cut. Further dissection was performed until the celiac artery became completely exposed and its branches identified. The postoperative period was uneventful and the patient was discharged 5 days later, with normal gastrointestinal transit and without recurrence of the abdominal pain. 1 month later, the patient remained asymptomatic. A long-term follow-up with annual duplex scan and clinical evaluation must be done, in order to evaluate the need of a revascularization due to persistent stenosis or aneurysmal degeneration.

CONCLUSION: MALS diagnostic and therapeutic approach must be patient focused, bearing in mind the multiple clinical presentation and treatment options. Open surgical decompression of median arcuate ligament is the base of therapy.