Shafik Ali A, Asaad Soheir, Loka Mona M, Wahdan Mohamed, Shafik Ahmed
Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Cairo, Egypt.
Clin Anat. 2009 Mar;22(2):243-9. doi: 10.1002/ca.20738.
To study the anatomical structure of the colosigmoid junction, 15 cadaveric specimens were studied morphologically, another 15 histologically, and a morphometric study was done in 10 specimens. Specimens consisted of the descending colon, sigmoid colon, and the colosigmoid junction. Histologic specimens were stained with hematoxylin and eosin and Masson's trichrome stain. Morphometric studies used an image analysis system. The colosigmoid junction was investigated endoscopically in 18 healthy volunteers. A narrow segment having a mean length of 5.2 +/- 1.1 cm was identified both externally and internally between the descending and sigmoid colon. We called this segment the colosigmoid canal. Mucosal folds were found crowded in the colosigmoid canal, the lower end of which formed a nipple and was surrounded by a fornix. Histologically, the colosigmoid canal mucosa showed multiple folds. Its circular muscle was thicker than that of the descending or the sigmoid colon and confirmed morphometrically. The longitudinal muscle was thicker in only 4 of 10 specimens. Both the narrowing and the mucosal crowding were verified endoscopically. The colosigmoid junction is the narrow segment between the descending and the sigmoid colon. Histologic, morphometric and endoscopic studies indicated the presence of a sphincter in the colosigmoid canal. A colosigmoid sphincter is suggested to control the passage of colonic contents from the descending colon to the colosigmoid canal as well as to prevent reflux of sigmoid contents into the descending colon.
为研究结肠乙状结肠连接部的解剖结构，对15例尸体标本进行了形态学研究，另外15例进行了组织学研究，并对10例标本进行了形态测量学研究。标本包括降结肠、乙状结肠和结肠乙状结肠连接部。组织学标本用苏木精-伊红染色和马松三色染色。形态测量学研究使用图像分析系统。对18名健康志愿者进行了结肠乙状结肠连接部的内镜检查。在降结肠和乙状结肠之间的外部和内部均发现一个平均长度为5.2±1.1 cm的狭窄段。我们将此段称为结肠乙状结肠管。发现结肠乙状结肠管内黏膜皱襞密集，其下端形成乳头并被穹窿包围。组织学上，结肠乙状结肠管黏膜显示出多个皱襞。其环形肌比降结肠或乙状结肠的环形肌厚，并经形态测量学证实。在10例标本中只有4例纵行肌较厚。狭窄和黏膜密集均经内镜证实。结肠乙状结肠连接部是降结肠和乙状结肠之间的狭窄段。组织学、形态测量学和内镜研究表明结肠乙状结肠管内存在括约肌。提示结肠乙状结肠括约肌可控制结肠内容物从降结肠进入结肠乙状结肠管，并防止乙状结肠内容物反流至降结肠。
