Duodeno-jejunal junction: a histoanatomical study with the concept of the existence of an “anatomical” sphincter

Abstract

Duodenojejunal junction (DJJ) pressure decreased on duodenal contraction and increased on jejunal contraction. These findings postulated potential existence of anatomical sphincter at DJJ. DJJ was studied by direct dissection in 34 cadavers and histologically in 24. Transverse and longitudinal sections across DJJ were cut and stained. DJJ was narrower than duodenum or jejunum and had one or two grooves occupied by arterial branch derived from superior mesenteric artery and we call it "duodenojejunal junction artery". DJJ was thicker on palpation than duodenum or jejunum. Its mucous membrane was crowded into "DJJ rosette". DJJ length varied in adults from 0.75 to 0.9 cm. Microscopically, circular muscle layer was thickened at DJJ. The thickened circular muscle, mucosal rosette and narrowing at DJJ point to possible existence of anatomical sphincter at DJJ. Together with presence of high-pressure zone at DJJ, these findings would support such postulation.