Duodeno-jejunal junction: a histoanatomical study with the concept of the existence of an "anatomical" sphincter.
BACKGROUND
Duodenojejunal junction (DJJ) pressure decreased on duodenal contraction and increased on jejunal contraction. These findings postulated potential existence of anatomical sphincter at DJJ.


METHODS
DJJ was studied by direct dissection in 34 cadavers and histologically in 24. Transverse and longitudinal sections across DJJ were cut and stained.


RESULTS
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.


CONCLUSIONS
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.
Shafik
Ahmed
A
Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Cairo, Egypt. shafik@ahmedshafik.com
Shafik
Ali A
AA
Wahdan
Mohamed
M
El Sibai
Olfat
O
D000293:Adolescent; D000328:Adult; D002102:Cadaver; D004386:Duodenum / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007583:Jejunum / Q000033:anatomy & histology*; D008297:Male; D008875:Middle Aged