RT Journal Article
T1 Fetal growth of the anal sinus and sphincters, especially in relation to anal anomalies
A1 Arakawa, Takashi
A1 Hwang, Si Eun
A1 Kim, Ji Hyun
A1 Wilting, Joerg
A1 Rodríguez Vázquez, José Francisco
A1 Murakami, Gen
A1 Hwang, Hong Pil
A1 Cho, Baik Hwan
AB Purpose and methods: The anal sinuses, small furrows above the pectinate line, sometimes form perianal abscesses in adults. We examined the pattern of fetal growth of the anal sinus and sphincters using 22 mid-term (8-18 weeks) and 6 late-stage (30-38 weeks) fetuses.Results: In mid-term fetuses, the external and internal sphincters gradually increased in thickness, depending on specimen size (from 0.2 to 1.5 mm), whereas the anteroposterior diameter of the anal canal at the epithelial junction was relatively stable (0.5-1.0 mm) irrespective of specimen size. Anal canal diameter increased less than twofold between mid-term and late-stage fetuses, from 0.5-1.0 to almost 2 mm, whereas sphincter thickness increased over tenfold, from 0.2-1.5 to almost 3.5 mm. The anal sinus often showed balloon-like enlargement when the sphincter muscle bundles were tightly packed in mid-term, but not in late-stage fetuses.Conclusions: Large concentric mechanical stress from the sphincters in late-stage fetuses apparently prevented the anal sinus from expanding in a balloon-like manner. Conversely, to avoid anal stenosis, the growing sinuses maintained a luminal space of the anal canal in response to stress from rapidly growing sphincters. The inferiorly extending sinus usually provided temporal double canals separated by a thick column. In the presence of double lumens, anal canal duplication is likely to develop without any abnormalities of the anal epithelium and sphincters.
PB Springer
SN 0179-1958
YR 2015
FD 2015-11-28
LK https://hdl.handle.net/20.500.14352/110090
UL https://hdl.handle.net/20.500.14352/110090
LA eng
NO Arakawa, T., Hwang, S.E., Kim, J.H. et al. Fetal growth of the anal sinus and sphincters, especially in relation to anal anomalies. Int J Colorectal Dis 31, 493–502 (2016). https://doi.org/10.1007/s00384-015-2455-8
DS Docta Complutense
RD 17 abr 2025