Ileocecal junction: anatomic, histologic, radiologic and endoscopic studies with special reference to its antireflux mechanism

Abstract

Aim: The aim of the study was to perform histomorphologic, endoscopic, and radiologic studies of the ileocecal junction (ICJ). A clearer understanding of the anatomical structure of the ICJ may shed some light on its function.

Methods: Histomorphologic studies were performed in 18 cadavers and radiologic in 22 and endoscopic in 10 healthy volunteers. Morphologic studies were done with the help of a magnifying loupe: histologic sections were stained with hematoxylin and eosin and Masson's trichrome. The ICJ was studied radiologically using the method of small bowel meal. Endoscopic study was done under controlled air inflation using a video endoscope.

Results: A nipple (1.5-2 cm long) with transversely lying stoma protruded from the medial wall of the cecum. A fornix was found on each side. The nipple stoma was surrounded by two lips: upper and lower. A mucosal fold started at both angles of the stoma and extended along the cecal circumference. It was marked on the outer cecal aspect by a groove.

Conclusion: The ileocecal nipple is a muscular tube with a transversely lying stoma and is suspended to the cecal wall by a "suspensory ligament". The morphologic structure of the ileocecal nipple was confirmed endoscopically and radiologically. The ileocecal nipple was closed at rest and opened upon terminal ileal contraction to deliver ileal contents to the cecum. It evacuated the barium periodically into the cecum. The ileocecal nipple structure seems to be adapted to serve the function of cecoileal antireflux.