Vascular compression of Duodenum: A case report of superior mesenteric artery syndrome

Abstract

Superior mesenteric artery (SMA) passes over the third part of duodenum and can cause its obstruction when the aorto-mesenteric angle is hyper acute. Although the condition is rare, the diagnosis can be made using radiography and the treatment consists of division of ligament of Treitz and duodenojejunostomy. We present a case of SMA syndrome in an elderly lady, who was managed successfully with surgery.

Introduction

Superior mesenteric artery (SMA) arises from abdominal aorta at level of L1 vertebra with an angle varying from 18 to 70°, whereas the duodenum crosses at L3 vertebra. A reduction of aortomesenteric angle due to loss of retroperitoneal fat may cause compression of the 3rd part of duodenum. There are number of alternative names attributed to this clinical condition such as vascular compression of duodenum, cast syndrome, aortomesenteric duodenal obstruction, superior mesenteric artery syndrome, nut cracker syndrome, and most notably as Wilkie syndrome. Less than 500 cases of SMA syndrome have been reported in English literature.¹

Case report

A 62-year-old female patient, who was a smoker presented with history of weight loss, pain abdomen, nausea, and fullness of upper abdomen for 3 months. There was no history of vomiting. Her past medical history was unremarkable. On examination, she was a pale elderly patient with Body- Mass- Index (BMI) of 15.2 kg/m². During per abdomen examination, fullness was noticed in epigastrium and left hypochondrium. Rest of the examination was normal. Patient consent for inclusion in study was also obtained.

Lab evaluation of hematological and biochemical parameters were within normal limits except for hypoalbuminemia. Contrast Enhanced Computed Tomogram (CECT) abdomen revealed gross dilatation of stomach and duodenum up to its 2nd part with narrowing in 3rd part. The narrowing was present between SMA and aorta (Fig. 1, Fig. 2).

Fig. 1.

CECT showing reduced distance between SMA and aorta with compression of the intervening 3rd part of duodenum (double headed arrow) with distended stomach and the 2nd part of duodenum (star). SMA, superior mesenteric artery.

Fig. 2.

Grossly distended stomach (star) with SMA seen traversing from left to right across duodenum (arrow). SMA, superior mesenteric artery.

Her nutrition status was built up with small frequent meals, high protein diet, and total parenteral nutrition. She was then taken up for duodenojejunostomy under GA. The ligament of Treitz was divided after incising the peritoneum at duodenojejunal flexure (Fig. 3). Then proximal jejunum and the 2nd part of duodenum were anastomosed in side-to-side fashion using a linear cutter and stapler. The enterotomy site was closed with sutures, and anastomosis was reinforced anteriorly with Lembert sutures (Fig. 4). Postoperatively, the patient recovered well. She gained seven kilograms in the next two months and her BMI improved to 17.9 kg/m².

Fig. 3.

Ligament of Treitz dissected out for division (arrow).

Fig. 4.

Completed side-to-side anastomosis of duodenum and jejunum.

Discussion

This condition was first described by Von Rokitansky in the late nineteenth century through a series of autopsy studies.² Wilkie described 75 patients with dilatation of duodenum and diagnosed them as chronic duodenal ileus.³

It is an uncommon condition causing duodenal obstruction with an incidence of 0.013%–0.3%.⁴ It is usually a disease of young adults with predominantly affecting women; however, it has been reported at extremes of age. The presentation is chronic with non-specific symptoms of early satiety, postprandial fullness, weight loss, nausea, vomiting, and occasionally pain. On examination, the patients are underweight with ill-defined fullness in epigastrium. Laboratory examination may reveal anemia, dyselectrolytemia, and hypoalbuminemia.

The diagnosis is clinched with contrast enhanced computed tomography. It provides information which includes duodenal distension, aorto-superior mesenteric artery distance, intra-abdominal, and retroperitoneal fat. An angle of less than 25° with aortomesenteric distance of less than 10 mm is the criterion for diagnosis.⁵ Other modalities used are fluoroscopy, ultrasonography, and Upper Gastro-intestinal (UGI) endoscopy; the latter two can be used in patients whom radiation is to be avoided.

Initial management is conservative with adequate nutritional built up, left lateral or prone positioning after meals. Total parenteral nutrition support may be warranted to improve weight. However medical management seldom leads to complete remission. Surgery is warranted in patients with prolonged history of weight loss, pronounced duodenal dilatation, and peptic ulcer complicating the disease or failure of non-operative management at 4–6 weeks.

The surgeries for SMA syndrome include duodenojejunostomy, gastrojejunostomy, or duodenal derotation (Strong procedure).⁵ The classic and the most favored approach to this condition is duodenojejunostomy, which can also be performed laparoscopically.⁶ The complications which are seen in this procedure include bleeding, leak, or stricture. The surgery consists of division of ligament of Treitz and side-to-side anastomosis of jejunum with the 2nd part of duodenum below the transverse mesocolon. Gastrojejunostomy is reserved if patient has duodenal ulcer disease or severe dilatation of stomach.⁷

Conclusion

SMA syndrome is a rare condition, which requires a high degree of suspicion when patient presents. However, the diagnosis can readily be made with use of modern radiographic techniques and laparoscopic management is a feasible option.

Disclosure of competing interest

The authors have none to declare.