1. Presenter; Pumzi, Abdul S. Resident Obs&Gyn Facilitator; Dr. Mboneko
INTERNAL ILIAC ARTERY
Presenter; Pumzi, Abdul S. Resident Obs&Gyn
Facilitator; Dr. Mboneko

2. Introduction
The internal iliac artery (formerly known as the hypogastric artery) is the main artery of the pelvis which supply blood to the Pelvis and Pelvic organs
The internal iliac artery supplies the walls and viscera of the pelvis, the buttock, the reproductive organs, and the medial compartment of the thigh.
The vesicular branches of the internal iliac arteries supply the bladder
It is a short, thick vessel, smaller than the external iliac artery, and about 3 to 4 cm in length.

4. Course
It arises at the bifurcation of the common iliac artery, opposite the lumbosacral articulation i. e. approximately at the level of the intervertebral disc between LV and SI and lies anteromedial to the sacro- iliac joint
Passing downward to the upper margin of the greater sciatic foramen where divides into two large trunks, an anterior and a posterior.

5. Course The following are relations of the artery at various points:
Anteriorly; the ureter
Posteriorly; the internal iliac vein, the lumbosacral trunk, and the piriformis muscle
Near its origin, it is medial to the external iliac vein, which lies between it and the psoas major muscle
It is above the obturator nerve.

6. Branches
The exact arrangement of branches of the internal iliac artery is variable. Generally, the artery divides into an anterior division and a posterior division
Posterior division giving rise to the superior gluteal, iliolumbar, and lateral sacral arteries. The rest usually arise from the anterior division.
Branches from the posterior trunk contribute to the supply of the lower posterior abdominal wall, the posterior pelvic wall, and the gluteal region

7. Posterior trunk
Branches of the posterior trunk of the internal iliac artery are the iliolumbar artery, the lateral sacral artery, and the superior gluteal artery

8. Posterior trunk
The iliolumbar artery ascends laterally back out of the pelvic inlet and divides into a lumbar branch and an iliac branch. The lumbar branch contributes to the supply of the posterior abdominal wall, psoas, quadratus lumborum muscles, and cauda equina via a small spinal branch that passes through the intervertebral foramen between LV and SI. The iliac branch passes laterally into the iliac fossa to supply muscle and bone.
The lateral sacral arteries, usually two, originate from the posterior division of the internal iliac artery and course medially and inferiorly along the posterior pelvic wall. They give rise to branches that pass into the anterior sacral foramina to supply related bone and soft tissues, structures in the vertebral (sacral) canal, and skin and muscle posterior to the sacrum.

9. Posterior trunk
The superior gluteal artery is the largest branch of the internal iliac artery and is the terminal continuation of the posterior trunk. It courses posteriorly, usually passing between the lumbosacral trunk and anterior ramus of S1, to leave the pelvic cavity through the greater sciatic foramen above the piriformis muscle and enter the gluteal region of the lower limb. This vessel makes a substantial contribution to the blood supply of muscles and skin in the gluteal region and also supplies branches to adjacent muscles and bones of the pelvic walls.

10. Anterior trunk
Branches of the anterior trunk of the internal iliac artery include
The superior vesical artery, the
Umbilical artery,
The inferior vesical artery,
The middle rectal artery,
The uterine artery,
The vaginal artery,
The obturator artery,
The internal pudendal artery
The inferior gluteal artery

11. Anterior trunk
The umbilical artery, which gives origin to the superior vesical artery, then travels forward just inferior to the margin of the pelvic inlet. Anteriorly, the vessel leaves the pelvic cavity and ascends on the internal aspect of the anterior abdominal wall to reach the umbilicus. In the fetus, the umbilical artery is large and carries blood from the fetus to the placenta. After birth, the vessel closes distally to the origin of the superior vesical artery and eventually becomes a solid fibrous cord. On the anterior abdominal wall, the cord raises a fold of peritoneum termed the medial umbilical fold. The fibrous remnant of the umbilical artery itself is the medial umbilical ligament.

12. Anterior trunk
The superior vesical artery normally originates from the root of the umbilical artery and courses medially and inferiorly to supply the superior aspect of the bladder and distal parts of the ureter. In men, it also may give rise to an artery that supplies the ductus deferens.
The inferior vesical artery occurs in men and supplies branches to the bladder, ureter, seminal vesicle, and prostate. The vaginal artery in women is the equivalent of the inferior vesical artery in men and, descending to the vagina, supplies branches to the vagina and to adjacent parts of the bladder and rectum.
The middle rectal artery courses medially to supply the rectum. The vessel anastomoses with the superior rectal artery, which originates from the inferior mesenteric artery in the abdomen, and the inferior rectal artery, which originates from the internal pudendal artery in the perineum.

14. Anterior trunk
The obturator artery courses anteriorly along the pelvic wall and leaves the pelvic cavity via the obturator canal. Together with the obturator nerve, above, and obturator vein, below, it enters and supplies the adductor region of the thigh.
The internal pudendal artery courses inferiorly from its origin in the anterior trunk and leaves the pelvic cavity through the greater sciatic foramen inferior to the piriformis muscle. In association with the pudendal nerve on its medial side, the vessel passes laterally to the ischial spine and then through the lesser sciatic foramen to enter the perineum. The internal pudendal artery is the main artery of the perineum. Among the structures it supplies are the erectile tissues of the clitoris and the penis.

15. Anterior trunk
The inferior gluteal artery is a large terminal branch of the anterior trunk of the internal iliac artery. It passes between anterior rami S1 to S2 or S2 to S3 of the sacral plexus and leaves the pelvic cavity through the greater sciatic foramen inferior to the piriformis muscle. It enters and contributes to the blood supply of the gluteal region and anastomoses with a network of vessels around the hip joint.
The uterine artery in women courses medially and anteriorly in the base of the broad ligament to reach the cervix. Along its course, the vessel crosses the ureter and passes superiorly to the lateral vaginal fornix. Once the vessel reaches the cervix, it ascends along the lateral margin of the uterus to reach the uterine tube where it curves laterally and anastomoses with the ovarian artery. The uterine artery is the major blood supply to the uterus and enlarges significantly during pregnancy. Through anastomoses with other arteries, the vessel contributes to the blood supply of the ovary and vagina as well.

18. Structure in fetus
In the fetus, the internal iliac artery is twice as large as the external iliac, and is the direct continuation of the common iliac.
It ascends along the side of the bladder, and runs upward on the back of the anterior wall of the abdomen to the umbilicus, converging toward its fellow of the opposite side.
Having passed through the umbilical opening, the two arteries, now termed umbilical, enter the umbilical cord, where they are coiled around the umbilical vein, and ultimately ramify in the placenta.

19. Structure in fetus
At birth, when the placental circulation ceases, the pelvic portion only of the umbilical artery remains patent gives rise to the superior vesical artery (or arteries) of the adult
The remainder of the vessel is converted into a solid fibrous cord, the medial umbilical ligament(otherwise known as the obliterated hypogastric artery) which extends from the pelvis to the umbilicus.

20. Variation
In two-thirds of a large number of cases, the length of the internal iliac varied between 2.25 and 3.4 cm.; in the remaining third it was more frequently longer than shorter, the maximum length being about 7 cm. the minimum about 1 cm.
The lengths of the common iliac and internal iliac arteries bear an inverse proportion to each other, the internal iliac artery being long when the common iliac is short, and vice versa.
The place of division of the internal iliac artery varies between the upper margin of the sacrum and the upper border of the greater sciatic foramen.
The right and left internal iliac arteries in a series of cases often differed in length, but neither seemed constantly to exceed the other.

21. Variation

22. Variation

23. Variation

24. LIGATURE OF THE INTERNAL ILIAC ARTERY
Indications: 
Tearing into the lower segment during or base of the broad ligament during a difficult Caesarean section.
Severe and persistent PPH when packing, Uterotonics and Bi-manual Compression of uterus fails to control bleeding.
Persistent bleeding from an abortion continuing after evacuation.
Rupture of the uterus.
Trauma to the uterus.

25. LIGATURE OF THE INTERNAL ILIAC ARTERY
Method: 
If patient's abdomen open, tying internal iliac arteries is quickly done But should not be done in too much of a hurry as must not damage the accompanying vein.
Often requires to open Abdomen and If so a quick lower median incision Is made, Hold back her abdominal contents and examine pelvic brim. ureter will be seen crossing common iliac artery at the point where it divides into its internal and external iliac branches
Peritoneum is opened and ureter is lifted
a haemostat is Inserted under internal iliac artery
The artery is tied with a ligature
the same procedure is repeated on the other side.

26. LIGATURE OF THE INTERNAL ILIAC ARTERY
CAUTION!
Never tie internal iliac vein which is closely related to the artery posteriorly. Doing so will increase the venous pressure in uterus and make bleeding from it worse.
Never damage internal iliac vein. If the vein is damaged, bleeding from the tear will be difficult to control and may necessitate to tie it.
On both sides, if necessary, also the anastomotic vessels that connect her ovarian arteries with uterine arteries may be tied as they pass on broad ligaments under the cornual ends of Fallopian tubes

28. Collateral Circulation
The circulation after ligature of the internal iliac artery is carried on by the anastomoses of:
The middle rectal artery and the superior rectal artery
The iliolumbar artery with the last lumbar artery
The lateral sacral arteries with the median sacral artery

29. Complications
Complications of internal iliac artery ligations are very rare because normal demands are met with extensive blood supply of Pelvic organs through collateral circulations.
Peripheral Neuropathy of the lower limbs may arise due to reduced blood supply to the main nerve trunks arising from the pelvis.

30. Fertility following ligation of internal iliac arteries for life- threatening obstetric haemorrhage: Case report
P.T. Wagaarachchi1 and 
L. Fernando
+Author Affiliations
Department of Obstetrics & Gynaecology, University of Kelaniya, Castle Street Hospital for Women, Sri Lanka
Received November 8, 1999.
Accepted February 8, 2000.
Abstract
Bilateral ligation of internal iliac (hypogastric) arteries (BIL) is a life-saving operation in cases of massive obstetric haemorrhage. This operation preserves reproductive function as opposed to the more commonly performed emergency hysterectomy in such situations. We report on effectiveness and future fertility in 12 women who had internal iliac ligation to control severe obstetric haemorrhage: in 10 out of the 12 women, BIL was successful. Of the two women who subsequently needed emergency hysterectomy, one woman died of disseminated intravascular coagulation. Of the eight women we were able to follow-up to assess reproductive performance, two did not desire future fertility. Three had subsequent pregnancies (50%), of whom two proceeded to term. We conclude that BIL is a safe and effective procedure for treating life-threatening obstetric haemorrhage with preservation of future fertility. This technique should be performed more often when indicated.
Source;

31. REFFERENCES
Gray's Anatomy for Students
WIKIPEDIA