Case Report - (2016) Volume 17, Issue 4
Department “B” of General Surgery, Charles Nicolle Hospital, Boulevard du 9 Avril, 1006 Tunis, Tunisia
Received date: February 24th, 2016 Accepted date: April 25th, 2016
Introduction Superior mesenteric artery syndrome is a rare cause of upper intestinal obstruction due to a compression of the third portion of the duodenum between aorta and superior mesenteric artery. Case presentation we report a case of 17 years old male patient which have a low body mass index. The diagnosis was confirmed by typical finding of the abdominal scan. Surgery was necessary after failure of initial conservative management. Conclusions This case of superior mesenteric artery syndrome to be implicated to the majority of patients without history of weight loss and the superiority of Duodenojejunostomy compared to gastrojejunostomy.
Body Mass Index; Intestinal Obstruction; Superior Mesenteric Artery Syndrome
Superior mesenteric artery syndrome (SMAS) is a rare condition, also known as Wilkie’s syndrome is caused by compression of the third portion of the duodenum between aorta and superior mesenteric artery (SMA). A reduced space between aorta and SMA less than 8 mm and an aorto- mesenteric angle less than 20 degrees causes a duodenal compression and stop the progression of the bolus explaining the high intestinal obstruction. Numerous predisposing conditions have been identified, but usually favored by rapid weight loss. We repot a case of a 17 years old male patient with low body mass index (BMI) and no history of recent weight loss. Surgical treatment was achieved after failure of initial conservative treatment.
A seventeen-year-old male patient with no significant medical history presented to our Emergency department with a complaint of upper abdominal pain, nausea, vomiting and abdominal distention for three days. His body mass index at admission was 15. There is no history of recent weight loss. The physical examination revealed a distended abdomen sensitive to palpation. Laboratory results were unremarkable. A standard X-ray showed distention of the stomach with air fluid level and duodenal gas (Figure 1). Abdominal CT-scan visualized major dilatation of the stomach, the first and the second portion of the duodenum. The junction level involved the third portion of the duodenum, which appeared compressed between the aorta and the superior mesenteric artery (SMA) due to a small aorto-mesenteric distance (4.4 mm) (Figure 2a). The aorto-mesenteric angle measured 11° (Figure 2b). The diagnosis of SMA syndrome was assumed and conservative management including parenteral nutrition and aspiration tube was started. Stomach tube produced 2L of bilio-digestive fluid daily. After ten days, this treatment was considered ineffective and open gastrojejunostomy was performed. Post operative period was marked by recurrence of symptoms after removal of the nasogastric tube. A second abdominal CT scan was performed and showed the same imaging features than last one. Twelve days later we have seen no improvement and we decided to practice a side-to-side duodenojejunostomy after removal of the initial gastrojejunostomy. The postoperative period was uneventful. Intestinal transit was noted on the second postoperative day. The patient was discharged on the seventh postoperative day. At the follow-up visit at 1 month and 3 months the patient had complete resolution of his preoperative symptoms.
Figure 1. Abdominal X-ray showed distension of the stomach with air fluid level and duodenal gas.
Figure 2. Abdominal computed tomography. Abdominal computed tomography showed distension of the stomach and the duodenal bulb due to compression of the third portion of duodenum. The distance between the abdominal aorta and superior mesenteric artery was 4.4 mm (a). The angle between the abdominal aorta and superior mesenteric artery was 11° (b). AAo, abdominal aorta; D, duodenum; SMA, superior mesenteric artery.
SMA syndrome was first described by Rokitansky in 1842. The pathogenic mechanism, as described by Wilkie in 1927, involves a small aorto-mesenteric space and extrinsic compression of the third portion of the duodenum between the SMA and the posterior structures. It is rare condition witch prevalence between 0.013 % and 0.3 % [1] that usually occur in young women between 18 and 35 years old [2]. Several pathophysiological theories have been advanced as the role of the mesenteric lymph nodes and the existence of a hypertrophied Treitz ligament. But the most common cause of SMA syndrome is severe weight loss including trauma, burns, chemotherapy, anorexia nervosa and/or after prolonged bed rest causing a massive and rapid reduction in the thickness of adipose tissue of the aorto- mesenteric space which is normally supposed to maintain the aorto mesenteric angle open and protects the duodenum of the vascular compression [3, 4]. A Wambre-Nicolas et al. [5] demonstrated that Aortomesenteric angle’s width is related to the bodymass index. In our patient the etiology of SMAS may be related to the undernutrition with low BMI. There are two non-specific clinical forms: The most common form (90 %) is made of chronic intermittent epigastric pain, nocturnal bilious vomiting worsening in supine position and improving by the left lateral or the seated positions. The second form, such as our case, is a rare form made of a severe bowel obstruction which can be life-threatening [2]. The diagnosis is confirmed by abdominal CT scan with contrast, which shows a gastroduodenal expansion to the third duodenal portion. The Arteriographic criteria include a significantly decreased aorto-SMA angle of 6° to 25° (nl=45°) and a shortened aortomesenteric distance of 2 to 8 mm (nl=10 to 20 mm) [6], which is the case in our observation. Complications can affect kidneys (renal failure, fluid and electrolyte disorders), or respiratory tract (acute respiratory failure) or the occurrence of gastric rupture [7, 8].
The main differential diagnosis to discuss is the mégaduodénum, another rare anomaly which represents a form of intestinal pseudo-obstruction of the small intestine localized in the upper part of the digestive tract. It is manifested by the same symptoms and the same radiological abnormalities. Only, bowel manometry studies or histological analysis of transmural biopsies of the duodenum could distinguish decide between these two pathologies.
Treatment is primarily medical with introduction of nasogastric tube suction gently with correction of electrolyte disturbances and introduction of parenteral or enteral feeding by a jejunostomy, whose goal is weight gain. Besides, left lateral decubitus or sitting position in order to reduce the pressure on the duodenum for the temporary relief of duodenal compression [9]. Myung Seok Shin et al. [10] reported a study including eighteen children with SMAS, medical management was successful in 72.2% and the median duration of this treatment was 45 days. If medical management fails, surgery should be comptemplated. Gastrojejunostomy is one option but seems to be associated with complications including dumping syndromes, blind loop syndrome, and marginal ulceration. Another option could also be Strong intervention which consists in dividing the Treitz ligament and lower the fourth portion of the duodenum. A major advantage of the procedure is the avoidance of a gastrointestinal anastomosis [11, 12]. Duodenojejunostomy is the third surgical option and can be used when either of the other operations fails. As we move in the era of laparoscopic surgery all this procedures can be laparoscopically achieved. We opted first for a gastrojejunostomy but twelve days later we have seen no clinical or radiological improvement so we decided to practice a duodenojejunostomy. Operating course was unenventful.
SMAS is a rare cause of duodenal obstruction. Contrast-enhanced computed tomography (CT) is noninvasive tool for diagnosis. First intention treatment is conservative management but surgery may necessary. Duodenojejunostomy should be the preferred technique as it seems to offer the best outcome.
The authors do not have any conflicts of interest to disclose.
