Postoperative superior mesenteric artery syndrome following appendicectomy: A case report.

Introduction: Superior mesenteric artery syndrome is a rare cause of proximal intestinal obstruction. It is caused by a narrow aortomesenteric angle resulting in external compression of the duodenum as it traverses between the abdominal aorta and the superior mesenteric artery. Presenting symptoms tend to be non-specific and aetiological risk factors for this syndrome remain subjects to debate. The lack of awareness for this phenomenon often results in a delayed diagnosis, yet it can predispose to potentially life-threatening complications.

Case Presentation: We describe an acquired case of SMA syndrome, in an 88-year old male who underwent an open appendicectomy 20 years prior. The patient presented with an 18-month history of progressive anorexia, weight loss, and intractable vomiting. After inconclusive initial investigations, an exploratory laparotomy demonstrated extensive postoperative adhesions, placing traction on the SMA through its ileocolic branch, resulting in acute angulation of the SMA and subsequent external duodenal compression.

Discussion: This case illustrates the acute evolving presentation of gastric and duodenal obstruction associated with SMA syndrome, and the need to raise the index of suspicion for its diagnosis. In this case, it is postulated that SMA syndrome presented as a late complication of an open appendicectomy - A rare presentation for a rare disease.

Conclusion: SMA syndrome is an uncommon, but important differential for upper gastrointestinal obstruction. This case illustrates the challenges in the diagnosis of this rare clinical entity. Further study is warranted to understand the varied aetiology and optimal management for patients presenting with SMA syndrome.