[Perineal aponeuroses. An anatomical study leading to the concept of perineal pubic-sacral cord]

Abstract

On the basis of anatomical dissections, the authors offer a description of the perineal thickness (centred on the study of its aponeuroses) which corresponds better with medical imaging (ultrasonography, MRI) findings. Situated between the pelvic floor (deep layer of the deep perineal aponeurosis) and the perineal skin (covering the superficial layer of the superficial perineal aponeurosis), the perineal thickness is organised around an antero-posterior functional entity: the pubic-sacral perineal cord. This is made up, from behind and going forwards, of: the urethro-clitorido-vulval entity, the peri-vulval insertion of the perineal aponeuroses, the tendinous centre of the perineum and the ano-coccygeal raphe. It forms the keystone of the perineal thickness by closing off the floor of the urogenital fossa, the transit point for prolapses. This organisation of the perineal thickness explains how the vulval orifice, with no truly effective specific muscular structure, opposes the forces of abdominal pressure, thus avoiding the development of prolapse under normal circumstances. The ischio-rectal fossa is also studied.