Initial management of SMAS is conservative, with gastric decompression, posture adjustment (prone, left lateral decubitus position), and correction of fluid/electrolyte imbalances. When SMAS is associated with cast syndrome, the body cast must be removed. This is promptly followed by aggressive nutritional support, with the goal of increasing body weight to increase retroperitoneal fat tissue and reexpand the aortomesenteric distance, thereby relieving duodenal obstruction. The preferred method is enteral feeding of small, frequent high-calorie meals. If symptoms persist or if the patient is unable to tolerate oral feedings, enteral feedings through a nasojejunal tube past the point of obstruction may be required. Alternatively, total parenteral nutrition or a combination of enteral and parenteral feedings may be used.[3,11,17]
Advances in nutritional treatments have dramatically improved the success rate of medical management.[4,7] However, surgery is indicated for symptomatic patients who do not respond to medical management. The optimal duration of medical management has not yet been established, but in general, a trial of 4-6 weeks of medical management and nutritional support is used before pursuing surgical treatment.[14,17]
Numerous surgical procedures have been described to treat SMAS. The Strong procedure involves mobilization of the duodenum by dividing the ligament of Treitz. It can be done laparoscopically, is less invasive, allows maintenance of bowel integrity, and is associated with earlier postoperative recovery; however, it has a high failure rate (25%), probably owing to short branches of the inferior pancreaticoduodenal artery that prevent the duodenum from falling caudally and away from the aorta.[9,18] Gastrojejunostomy allows gastric decompression but may result in dumping syndromes and failure to adequately relieve duodenal obstruction. This leads to recurrent symptoms that may necessitate a second operation. Persistent unrelieved obstruction may also result in blind loop syndrome and gastric reflux with peptic ulceration.[7,9,18,19]
Duodenojejunostomy is regarded as the procedure of choice for SMAS. It was first described by Stavely in 1908, can now be performed laparoscopically, and has a success rate of up to 90%.[18,20] The advent of laparoscopic surgery has allowed faster recovery, decreased postoperative pain, and decreased length of operation, all while providing the same favorable results as open surgery.[14,21,22]
In this procedure, the third portion of duodenum is mobilized to the right of the superior mesenteric vessels (artery and vein), and a side-to-side duodenojejunostomy is created between the third part of duodenum and jejunum distal to ligament of Treitz, to bypass the area of compression created by SMA. Development of blind loop syndrome can be further diminished with a Roux-en-Y duodenojejunal bypass, allowing free drainage of duodenum both proximal and distal to the SMA compression site.
The patient in this case underwent laparoscopic duodenojejunostomy and had an uneventful postoperative recovery. Oral nutrition was reinstated on postoperative day 2, with clear liquids and advancement to soft diet by day 5. No complications, such as wound infection or anastomotic leak, occurred. The length of his hospital stay was 5 days. His nausea and vomiting disappeared. Follow-up at 18 months showed significant improvement of symptoms and better quality of life.
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