AB157. SOH24AB_274. A case of superior mesenteric artery syndrome post correction of malrotation

Background: Superior mesenteric artery (SMA) syndrome is a rare condition defined as the compression of the third portion of the duodenum between the abdominal aorta and the SMA. The incidence is estimated at 0.1% to 0.3%. This usually occurs due to a loss of intervening mesenteric fat between the aorta and SMA, it is often associated with significant weight loss.

Case Description: A 39-year-old male presented for elective correction of malrotation and right hemicolectomy. Intra-operatively, there was found to be significant malrotation of the small bowel mesentery with a two-thirds anticlockwise twist. The initial postoperative period was complicated by a prolonged ileus resulting in a 9 kg weight loss (15% body weight). Persisting nausea and vomiting prompted further imaging showing an acute cut-off at the level of the third part of the duodenum (D3). Subsequent exploratory laparotomy showed a narrowing of D3 queried to be an adhesional narrowing. Post-operative magnetic resonance imaging (MRI) enterography showed gross distension of the stomach and duodenum with a change in calibre of the duodenum at the level of D3 where the SMA crossed. The patient returned to theatre for a gastrojejunostomy to relieve the obstruction following failed conservative management with nutrition support and was subsequently discharged.

Conclusions: SMA syndrome is a rare cause of upper gastrointestinal obstruction, it is often difficult to diagnose and should be considered in young patients with persistent vomiting following significant weight loss. Conservative management to increase the aortomesenteric angle can be trialled, however, often bypass with gastrojejunostomy or duodenojejunostomy is required.

Keywords: Gastrointestinal surgery; gastrojejunostomy; general surgery; malrotation correction; superior mesenteric artery syndrome (SMA syndrome)