European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 20 - Number 1
Eur J Anat, 20 (1): 79-85 (2016)

Fetal intraluminal portion of the sphincter of Oddi: a histological study using human fetuses

Hee Chul Yu1,2, Hong Pil Hwang1,2, Ji Hyun Kim3, Masahito Yamamoto4, Gen Murakami5, Baik Hwan Cho1,2

1Department of Surgery, Chonbuk National University Medical School, Jeonju, Korea, 2Research Institute of Clinical Medicine, Chonbuk National University-Biomedical Research Institute, Chonbuk National University Hospital, Jeonju, Korea, 3Department of Anatomy, Chonbuk National University Medical School, Jeonju, Korea, 4Department of Anatomy, Tokyo Dental College, Tokyo, Japan, 5Division of Internal Medicine, Iwamizawa Asuka Hospital, Iwamizawa, Japan

ABSTRACT The sphincter of Oddi surrounds a common duct after joining of the bile and pancreatic ducts in the adult ampulla of Vater, but the fetal development of the submucosal portion of the sphincter is still obscure possibly because previous studies used horizontal or frontal sections. We examined serial sagittal histological sections of 12 human fetuses with 36-65 mm crown rump length or CRL (approximately 9-11 weeks) and semi-serial sections of the other 3 fetuses with 210-250 mm (25-30 weeks). Except for 1 fetus (36 mm CRL), fourteen fetuses carried the ‚??intraluminal portion‚?Ě protruding and floating in the duodenal lumen. Twelve of them had the sphincter extending to the anal side in the duodenal lumen, whereas two extended to the stomach side. The distal end of the sphincter seemed to detach from the duodenal mucosa at and around 9 weeks, and subsequently the common duct seemed to elongate freely without mucosal attachment in mid-term fetuses and, finally, become embedded again in the duodenal mucosa in the postnatal life. A possible discrepancy in growth rate between the sphincter muscle and duodenal mucosa was likely to allow the specific intermediate morphology, i.e., the intraluminal common duct. The fetal accessory papilla did not show such morphology. A minority of cases whose common duct extended to the stomach side might connect with abnormal union of the bile and pancreatic ducts.

Keywords: Sphincter of Oddi, Ampulla of Vater, Submucosal portion, Intraluminal common duct, Human fetus

European Journal of anatomy
ISSN 2340-311X (Online)