**6. Treatment**

416 New Advances in the Basic and Clinical Gastroenterology

Fig. 1. Left, the normal angle between the superior mesenteric artery (SMA) and the aorta is 25 to 60 degrees. Right, in SMA syndrome, the SMA-aortic angle is more acute, and the duodenum is compressed between the aorta and the SMA (Reproduced with permission


The most common symptom in these patients is intermittent abdominal pain and copious vomiting. The abdominal pain can be postprandial and the nausea, vomiting can lead to anorexia and weight loss. Early satiety, eructations, and at times sub-acute small bowel obstruction can develop. The symptoms are relieved when patient lies in left lateral decubitus, prone or knee-to-chest position (Geer 1990, Wilkie 1927, Raissi et al 1996). They are often aggravated by in an asthenic patient in supine position. Examination of the abdomen may reveal a succussion splash. Peptic ulcer disease is found in 25-45% of the patients and hyperchlohydria in 50 %( Geer 1990, Ylinen et al 1989). Dilated duodenum and stomach could predispose a patient to aspiration pneumonia and acute gastric rupture.

To diagnose a patient with SMAS traditionally barium meal studies with hypotonic duodenography is being used. A positive diagnosis will include duodenal dilatation, retention of barium with in duodenum, the classical vertical linear impression caused by extrinsic pressure in the third part of duodenum and frequent relief of obstruction in left lateral or decubitus position (Tsirikos , Jeans 2005, Raissi et al 1996). In the past angiographic measurement of the aortomesenteric angle was thought to be a gold standard. An aortomesenteric angle of < 22–25° and a distance of <8 mm correlated well with symptoms of SMAS (Hines et al 1984). Because of its invasive nature, Computed tomography (CT) scan or CT angiogram/MR angiogram have taken over as a gold standard (Tsirikos , Jeans 2005,

from Pasumarthy et al (2010) Cleveland Clinic Journal of Medicine. 77:45-50)

**4. Symptoms and signs** 

**5. Diagnosis** 

If there is a neoplasm causing SMAS, anatomic or congenital abnormality then the treatment is surgical, otherwise this condition is treated conservatively. Patients are fed frequent small meals orally or if it is not possible then through enteral jejunal tube. After feeding the patient, he/she should be placed in either prone or lateral decubitus position. If patient cannot tolerate tube feeding because of excessive vomiting then he/she needs to be fed parentally. Both ways of feeding have shown to be effective (Barnes, Lee 1996).This conservative treatment should aim to correct the fluid and electrolyte balance and increase the body weight in an attempt to increase the retroperitoneal fat so that the aortomesenteric angle is corrected.

Surgical treatment is indicated if conservative treatment fails or if there is severe progressive weight loss, pronounced duodenal dilatation with stasis and complicating peptic ulcer disease. Several surgical procedures have been tried and tested in the management of SMAS. Gastrojejunostomy, dudenojejunostomy, Strong's operation (duodenal mobilisation for lowering the duodenojejunal flexure) have been performed to treat this condition. Gastrojejunostomy and lysis of the ligament of Treitz provided adequate decompression of the stomach but was not helpful in overcoming the duodenal obstruction and at times leading to blind loop syndrome with reflux of bile necessitating duodenojejunostomy (Lee, Mangla 1978). A review of 146 cases showed that duodenojejunostomy was the treatment of the choice (Lee, Mangla 1978) and success rate was 90 %(Raissi et al 1996). Recently laparoscopic dudenojejunostomy has become treatment of choice. Massoud (1995) reported his experience of laparoscopic division of the ligament of Treitz in 4 cases. It was successful in 3 cases. Gerson and Heniford (1998) reported first laparoscopic duodenojejunostomy and then further cases were reported in the literature (Richardson, Surowiec 2001). Minimally invasive surgery with less operative time, quick post operative recovery and relief of the symptoms were the advantages over traditional duodenojejunostomy.
