Endoanal ultrasound images of external anal sphincter
Endoanal ultrasound images of external anal sphincter
(A) The superficial EAS. (B) The main portion of the EAS. (C) The incomplete part of EAS. (D) The sling created by puborectalis muscle. (E) The sling created by the pubococcygeus muscle. (F) The mid-sagittal view of the anal canal.
A: anterior; EAS: external anal sphincter; I: internal anal sphincter; M: main part of EAS; P: posterior; PC: pubococcygeus; PR: puborectalis; S: superficial EAS; T: transducer; V: vagina.
Reproduced with permission from Seyed Abbas Shobeiri, MD, FACS, FACOG.