Arterial Supply and Venous Drainage of Pelvis.pptx

The rich vascular supply of the pelvis not only supports the structures contained within it, including the bladder, rectum, and reproductive organs, but also extends to the lower extremities. For a complete understanding of vascular anatomy as it pertains into the endovascular procedures of interventional radiology, it is useful to discuss the vascular structures in sections, from the bifurcation of the aorta and the inferior vena cava to the level of the common femoral arteries and veins. We will also review the anatomy of the iliac vessels, including their branches, common variants, and various collateral pathways

1. Blood Supply of Pelvis Dr Mathew Joseph MBBS,MD(AIIMS),BCC(Palliative Medicine) Assistant Professor Department of Anatomy Amala Institute of Medical Sciences, Thrissur

2. Blood Supply of Pelvis The pelvic cavity contains the organs of reproduction, urinary bladder, pelvic colon, rectum and numerous muscles. Its arterial supply is largely via the internal iliac artery , with some smaller arteries providing additional supply.

3. Internal Iliac Artery The internal iliac artery is the major artery of the pelvis. It originates at the bifurcation of the common iliac artery into its internal and external branches approximately at vertebral level L5-S1. The artery descends inferiorly, crossing the pelvic inlet to enter the lesser pelvis. During its descent, it is situated medially to the external iliac vein and obturator nerve. At the superior border of the greater sciatic foramen , it divides into anterior and posterior trunks.

4. Posterior Division of Internal Iliac Artery Iliolumbar artery – Ascends to exit the lesser pelvis, dividing into a lumbar and iliac branch. The lumbar branch supplies psoas major, quadratus lumborum and the posterior abdominal wall. The iliac branch supplies the muscles and bone around the iliac fossa. Lateral sacral arteries (superior and inferior) – Travel infero-medially along the posterior pelvic wall to supply structures in the sacral canal, and the skin and muscle posterior to the sacrum. Superior gluteal artery – The terminal branch of the posterior trunk. It exits the pelvic cavity via the greater sciatic foramen, entering the gluteal region superiorly to the piriformis muscle. It is the major blood supply to the muscles and skin of the gluteal region.

5. Anterior Division of Internal Iliac Artery Obturator artery – Travels through the obturator canal, accompanied by the obturator nerve and vein. It supplies the muscles of the thigh’s adductor region. Umbilical artery – Gives rise to the superior vesical artery, which supplies the superior aspect of the urinary bladder. Inferior vesical artery – Supplies the lower aspect of the bladder. In males, it also supplies the prostate gland and seminal vesicles. Vaginal artery (female) – Descends to the vagina, supplying additional branches to the inferior bladder and rectum. Uterine artery (female) – Travels within the cardinal ligament to reach the cervix, where it ascends along the lateral aspect of the uterus. At origin of the fallopian tubes, it anastomoses with the ovarian artery. During its course, it crosses the ureters superiorly.

6. Anterior Division of Internal Iliac Artery Middle rectal artery – Travels medially to supply the distal part of the rectum. It also forms anastomoses with the superior rectal artery (derived from the inferior mesenteric) and the inferior rectal artery (derived from the internal pudendal) Internal pudendal artery – Moves inferiorly to exit the pelvis via the greater sciatic foramen. Accompanied by the pudendal nerve, it then enters the perineum via the lesser sciatic foramen. It is the main artery responsible for the blood supply to the perineum. Inferior gluteal artery – The terminal branch of the anterior trunk. It leaves the pelvic cavity via the greater sciatic foramen, emerging inferiorly to the piriformis muscle in the gluteal region. It contributes to the blood supply of the gluteal muscles and hip joint.

7. Minor Arteries of Pelvis Gonadal Arteries : The ovarian artery is the major gonadal artery in females. It arises from the abdominal aorta, distal to the origin of the renal arteries. The artery descends towards the pelvis, crossing the pelvic brim and the origin of the external iliac vessels. It moves medially, dividing into an ovarian branch and tubal branches, which supply their respective structures . Median Sacral Artery : Originates from the posterior aspect of abdominal aorta, at its bifurcation into the common iliac arteries. It descends anteriorly to the L4 and L5 vertebrae, the sacrum and the coccyx, contributing to the arterial supply of these regions. Superior Rectal Artery : Is the terminal continuation of the inferior mesenteric artery. It crosses the left common iliac artery and descends in the mesentery of the sigmoid colon. It gives rise to branches that supply the rectum.

8. Venous Drainage of Pelvis The pelvic venous system is responsible for taking blood from the pelvic walls and viscera back to the main circulation. Like the arterial analogues, the external iliac vein primarily drains the lower limbs, while the internal iliac vein drains the pelvic viscera, walls, gluteal region and perineum. The veins of the pelvis drain deoxygenated blood and return it to the heart. There are three major vessels involved in the venous drainage of the pelvis – the external iliac vein, internal iliac vein and common iliac vein (these correspond the major pelvic arteries).

9. External Iliac Vein The external iliac vein is a continuation of the femoral vein, arising when the femoral vein crosses underneath the inguinal ligament. It ascends along the medial aspect of the external iliac artery, before joining with the internal iliac vein to form the common iliac vein. During its short course, the external iliac vein receives the inferior epigastric and deep circumflex iliac veins

10. Internal Iliac Vein The internal iliac vein is responsible the majority of pelvic venous drainage, and receives numerous tributaries from veins that drain the pelvic region. It is formed near the greater sciatic foramen, ascending anteriorly to the sacroiliac joint, before combining with the external iliac vein to form the common iliac vein.

11. Internal Iliac Vein Superior and inferior gluteal veins – drains the buttock and upper thigh. Internal pudendal vein – drains the reproductive organs and part of the rectum (via the inferior rectal vein). Obturator vein Lateral sacral veins – drains part of the sacrum. Middle rectal vein – drains the bladder, prostate (in males only), and part of the rectum. Vesical veins – drains the urinary bladder via the vesical venous plexus. Uterine and vaginal veins – drain the female reproductive organs via the vaginal and uterine venous plexuses

12. Common Iliac Vein The common iliac vein is formed at the upper margin of the pubic symphysis by the union of the external and internal iliac veins. It receives two additional tributaries: Iliolumbar vein – drains the L4 and L5 vertebrae, and the iliopsoas muscle. Middle sacral veins – drain part of the sacrum. The left and right common iliac veins combine at L5 to become the inferior vena cava, which empties into the inferior aspect of the right atrium.

13. Thank You