Anatomical Relations
The pudendal (Alcock’s) canal is a passageway within the obturator fascia that covers the medial aspect of the obturator internus muscle. The passageway begins at the posterior border of the ischioanal fossa and runs from the lesser sciatic notch, below the ischial spine, to the posterior margin of the perineal membrane. The pudendal canal also makes up the lateral wall of the ischioanal fossa.
The pudendal canal transmits the internal pudendal artery and vein, the pudendal nerve, and the nerve to the obturator internus.
As the vessels enter the canal, they give rise to the inferior rectal vessels and nerves, which run through its medial wall and give off branches which supply the external anal sphincter and perianal skin. At the anterior end of the canal, the internal pudendal artery and nerve give rise to the perineal artery and nerve. They supply the muscles within the deep and superficial perineal pouches, the skin, and external genitalia (glans clitoris in females and the glans penis in males).
Structure
The pudendal canal is an obliquely lying passageway within the obturator fascia, with a mean length of 1.6 cm in adults (Shafik and Doss, 1999). It is embedded within loose areolar tissue from the medial ischioanal fossa. The wall of the pudendal canal consists of collagen and elastic fibers.
Function
The pudendal canal transmits and encloses vessels that pass to and from the urogenital triangle, i.e., the internal pudendal artery and vein, the pudendal nerve, and the nerve to the obturator internus. The crisscross orientation of the collagen fibers in the wall allows the canal to change shape in response to the changes in pudendal vessels that occur with the functions of the sexual organs, external genitalia and pelvic floor muscles.
List of Clinical Correlates
—Pudendal nerve entrapment
—Pudendal canal syndrome
References
Shafik, A. and Doss, S. H. (1999) 'Pudendal canal: surgical anatomy and clinical implications', Am Surg, 65(2), pp. 176-80.
