RESUMEN
Arteriomesenterial compression (AMC) of a low-horizontal part of the duodenum is one of the causes of chronic duodenal obstruction (CDO). The degree of compression of this part of the duodenum was studied in 82 patients with CDO. It was revealed that distance between the aorta and superior mesenterial artery (SMA) on the level of low-horizontal part of the duodenum was less than 20 mm in the majority of cases. When this distance is 20 mm or less the duodenum is compressed by SMA and looks like sand-glass. If the distance between the aorta and SMA is 10 mm and less, delay of contrast in the middle third of a low-horizontal part of the duodenum during roentgenography is an obligate symptom. In AMC 10-20 mm this phenomenon is diagnosed less frequently. In AMC 20 mm and less endoscopy demonstrates symptoms of CDO in the majority of cases. There were no intraoperative subjective symptoms of AMC.