Benign duodenal stasis, also known as superior mesenteric artery syndrome, is an obstruction of the intestinal lumen caused by compression of the horizontal portion of the duodenum by the superior mesenteric artery (or its branch, the middle colonic artery). The disease is rare and most often occurs in young and middle-aged women with long and lean bodies. Etiology and pathology The horizontal portion of the duodenum crosses the collecting and abdominal aorta transversely at the level of the third lumbar vertebra. The mesenteric artery emanates from the abdominal aorta just below the lower edge of the neck of the pancreas and crosses in front of the third part of the duodenum. When the angle formed between the two arteries becomes small, the superior mesenteric artery presses the horizontal part of the duodenum toward the vertebral body or abdominal aorta then into intestinal lumen narrowing and obstruction. The causes of stasis are comprehensive, i.e., low location of the origin of the superior mesenteric artery, short pulling of the duodenal suspensory ligament, overstretching of the collection, weight loss or loss of the fat pad between the abdominal aorta and the superior mesenteric artery due to a hypercatabolic state. Other causes of chronic duodenal stasis include cricothyroid pancreas, visceral prolapse and intra-abdominal adhesions that pull on the mesentery. Clinical manifestations Benign duodenal stasis often occurs intermittently, highlighted by chronic postprandial colic with chronic recurrent epigastric pain, accompanied by epigastric fullness, intermittent vague or dull pain, belching, nausea and vomiting. Vomiting often occurs several hours after a meal or at night, as bile-containing and meal-separated food, and the symptoms may be relieved after vomiting. Patients are prone to vomiting when standing or sitting after eating; patients often find that taking a certain position during an attack can alleviate symptoms, such as prone or left-sided position, chest and knee position, forward leaning sitting position with both knees under the jaw, etc. Long-term recurrent seizures may result in wasting, malnutrition, anemia and disorders of water-electrolyte metabolism. Signs can be seen as gastric pattern and peristaltic waves, positive epigastric vibro-hydraulic sounds, and intra-abdominal water beat and hyperactive bowel sounds can be heard. Laboratory and other examinations I. X-ray barium meal examination 1. The barium is interrupted at the midline of the spine at the level of the duodenum, and there is a neat oblique cut resembling pencil compression (pencil sign), and the passage of barium is obstructed here. 2.The proximal duodenum and stomach are dilated and there is obvious duodenal retroperistalsis; 3.The lumen of the intestine distal to the incision is deflated and the barium cannot be emptied within 2-4 hours now; 4.The barium can rapidly pass through the horizontal part of the duodenum into the jejunum when lying on the side or prone. Second, ultrasonography Measure the angle between superior mesenteric artery and abdominal aortic pulp, normal 30°-50°, with stasis <13°; the anterior-posterior diameter of duodenal lumen at the compression of superior mesenteric artery in the angle <1.0cm, while the anterior-posterior diameter of proximal duodenal lumen >3.0cm. Third, CT combined with arteriography or spiral CT Three-dimensional graphics can reveal the relationship between superior mesenteric artery and duodenum and obstruction at this level. Diagnosis and differential diagnosis Patients with recurrent vomiting of bile and gastric contents, especially in patients with reduced symptoms with postural changes, should be considered for this disease. Pay attention to the identification of other lesions that cause obstruction to emptying of the transverse or ascending duodenum, such as cricothyroid pancreas, duodenal carcinoma, tuberculosis, and Crohn’s disease. The X-ray signs of these diseases are clearly different from those of superior mesenteric artery compression, which are easily identified. Another thing to distinguish is congenital megaduodenosis and scleroderma with duodenal dilatation, the emptying disorder of these diseases is dynamic and not difficult to distinguish. Treatment I. Non-surgical treatment Fasting, gastrointestinal decompression, correction of water-electrolyte balance and parenteral nutrition support should be given during the attack of obstruction. During the remission period, rest, elevation of the foot of the bed and abdominal massage should be given. Suction and flushing of the duodenum, small and frequent meals, a dregs-free and nutritious diet, and a left-sided, prone or thoracic-knee position after eating. Internal administration of atropine, phenobarbital and other drugs can be temporarily effective. Surgical treatment 1, duodenojejunostomy for duodenal obstruction of the third segment, surgery requires the jejunum from the flexor ligament 10-15cm, and the distended duodenal third segment anastomosis, anastomosis at least 5cm, to prevent the intestinal contents through the poor. 2, gastrojejunostomy duodenum around the adhesions more, exposure difficulties before use, to avoid the occurrence of intestinal fistula. 3.Duodenal suspensory ligament release is suitable for those whose duodenal suspensory ligament is too short.