Branches of the Internal Iliac Artery
The internal iliac artery (also called the hypogastric artery) divides into anterior and posterior divisions, with the anterior division giving rise to the umbilical, superior vesical, obturator, middle rectal, inferior vesical (or vaginal in females), uterine (in females), inferior gluteal, and internal pudendal arteries, while the posterior division gives rise to the iliolumbar, lateral sacral, and superior gluteal arteries. 1
Anatomical Organization
Anterior Division Branches
The anterior division supplies primarily visceral and perineal structures:
- Umbilical artery – most commonly the first branch of the anterior division (48.5% of cases) 2
- Superior vesical artery – supplies the superior bladder 1
- Obturator artery – courses to the medial thigh region 3
- Middle rectal artery – supplies the rectum 1
- Inferior vesical artery (males) or vaginal artery (females) – supplies bladder base or vagina 1
- Uterine artery (females only) – additional branch in females, typically originates approximately 12 mm from the origin of the anterior division 2
- Inferior gluteal artery – most commonly the last branch of the anterior division (68.4% of cases), exits pelvis below piriformis muscle 2, 3
- Internal pudendal artery – most prevalent branch overall (present in 90.5% of cases), supplies perineum 2, 1
Posterior Division Branches
The posterior division supplies primarily parietal structures:
- Iliolumbar artery – supplies iliacus and psoas muscles 1
- Lateral sacral artery – supplies sacral region 1, 3
- Superior gluteal artery – largest branch, exits pelvis above piriformis muscle 1, 3
Clinical Significance
Surgical and Interventional Considerations
Preservation of at least one internal iliac artery is strongly recommended during aorto-iliac aneurysm repair to prevent pelvic ischemia. 4, 5, 4
- Unilateral internal iliac artery exclusion causes buttock claudication in 27% of patients 4, 5
- Bilateral exclusion increases this risk to 36% 4, 5
- Erectile dysfunction occurs in 10% of men following internal iliac artery sacrifice 4, 5
- Serious complications (spinal, bowel, and gluteal ischemia) occur in <1% of cases but are devastating 5
Anatomical Variability
Significant variation exists in the branching pattern, with only 46.8% of specimens following the classic textbook description. 6
- Type I pattern (division into anterior and posterior trunks) occurs in approximately 60.6% of cases 7
- In nearly 80% of cases, the internal iliac artery divides into the superior gluteal artery and a common trunk of the inferior gluteal and internal pudendal arteries 6
- The internal iliac artery may terminate without dividing into two trunks in a significant number of specimens 7
- Considerable interchange of branches between the two terminal divisions is common 7
Hemorrhage Control
Knowledge of internal iliac artery anatomy is essential for successful ligation during acute pelvic hemorrhage and for interventional radiological procedures. 1
- The median diameter at the origin of the anterior division is 5.76 mm with a cross-sectional area of 24.77 mm² 2
- Detailed morphometric data aids in selective catheterization for intra-arterial chemotherapy and embolization of pelvic tumors 1
- Erroneous interpretation of variant arteries commonly leads to accidental hemorrhage and neurovascular injuries during surgical procedures 1
Pelvic Radiation Therapy Planning
When planning radiation therapy for rectal cancer, nodes along the internal iliac arteries up to the level of S1-2 should be included in the clinical target volume for tumors below the peritoneal reflection. 8