Internal pudendal artery

Origin and course

The internal pudendal artery is a smaller terminal branch of the anterior division of the internal iliac artery originating between the iliopectineal line and greater sciatic notch. For didactic purposes, the course of the internal pudendal artery can be divided into three parts;

• Pelvic part: It has a short inferolateral course in the pelvis, crossing the piriformis muscle and the sacral plexus.
• Gluteal part: The artery passes from the pelvic to the gluteal region through the greater sciatic foramen, passing inferior to the piriformis muscle (infrapiriform foramen). While located in this region, the artery winds around the posterior aspect of the ischial spine and sacrospinous ligament.
• Perineal part: The internal pudendal artery enters the perineum through the lesser sciatic foramen. It initially traverses the ischiorectal fossa, situated in the Alcock's canal (pudendal canal) with the pudendal vein and nerve. Alcock's canal consists of the ischiopubic rami and fascia of obturator internus, laterally and medially, respectively. The artery then runs anteromedially along the inferior pubic ramus and enters the deep perineal pouch, situated above the perineal membrane. It terminates by giving off the terminal branch called the dorsal artery of the penis/clitoris.

Branches and supply

Along its path, the internal pudendal gives off numerous branches for the vascularization of the muscles and skin of the anogenital region, as well as internal and external genital organs.

• The inferior anorectal artery stems from the internal pudendal artery in the pudendal canal. It then passes through the ischiorectal fossa to supply the inferior portion of the rectum (inferior to the pectinate line), anal sphincters and the adjacent skin.
• The perineal artery originates in the distal portion of the pudendal canal passing anteriorly and inferior to the perineal membrane. It supplies the musculature of the superficial perineal pouch. Most importantly, it gives rise to the posterior scrotal/labial  artery that supplies the skin of scrotum in males or labia majora and minora in females.
• The artery of the bulb of the penis/vestibule arises after the internal pudendal artery enters the deep perineal pouch. In males, it supplies the bulb of penis and the adjacent part of the urethra and bulbo-urethral gland. In females, it supplies the bulb of vestibule and greater vestibular gland. This branch can also provide an additional urethral branch that supplies the external urethral sphincter.
• The deep artery of the penis/clitoris also originates in the deep perineal pouch. It traverses the perineal membrane and then runs through the middle of each of the corpora cavernosa of the penis/clitoris supplying them.
• The dorsal artery of the penis/clitoris is a terminal branch of the internal pudendal artery arising also in the deep perineal pouch. It passes between the perineal membrane and the pubic symphysis to run along the dorsal surface of the penis/clitoris. It supplies the perineal pouch, corpus spongiosum in males and the adjacent skin and fascias of external genitalia (penis or clitoris).

To learn more about the blood vessels of the pelvis, check out our other articles, videos, labeled diagrams and quizzes.

Anatomical variations

The internal pudendal can arise separately from the anterior division of the internal iliac artery or it can share a common origin with the inferior gluteal and obturator arteries.

In some cases, an additional perineal artery can be present. It is referred to as the accessory pudendal artery and it usually arises from the pelvic segment of the internal pudendal artery. It can be unilateral or bilateral, as a single or double vessel on each side. The rates of presence of this artery vary across literature, from 10-30%. This artery can provide some of the branches that usually arise from the internal pudendal artery.