Anatomical Variations and Branching Pattern of the Internal Iliac Artery: A Cadaveric Study

Background: The internal iliac artery (IIA) is the principal arterial supply to the pelvic viscera, gluteal region, andperineum. Variations in its origin, course, and branching pattern are clinically important during pelvic surgeries, orthopaedicprocedures, and endovascular interventions. The aim is to study the anatomical variations and branching pattern of theinternal iliac artery in cadaveric specimens. Materials and Methods: This descriptive cadaveric study was conducted in theDepartment of Anatomy, Index Medical College and Hospital, Indore, India. A total of 60 embalmed adult cadavers (120pelvic halves) were dissected. The vertebral level of origin, distance from the midsagittal plane, relation to the sacroiliacjoint, length, diameter, termination pattern, level of division relative to the greater sciatic foramen, and branching patternaccording to Adachi’s classification were recorded. Variations in the origin of major branches such as the obturator, inferiorgluteal, iliolumbar, internal pudendal, superior vesical, and middle rectal arteries were also analyzed. Results: The mostcommon vertebral level of origin of the internal iliac artery was between L5 and S1 (48.3%). The artery was most commonlylocated 30–40 mm from the midsagittal plane and was found medial to the sacroiliac joint in 61.67% of specimens. The mostfrequent length was 30–40 mm (40%), while the most common external diameter was 7–8 mm (40%). The internal iliacartery is terminated by bifurcation into anterior and posterior divisions in 71.67% of cases. According to Adachi’sclassification, the most common branching pattern was Type Ia (56.67%). The obturator artery most frequently originatedfrom the anterior division (36.67%), while the inferior gluteal artery most commonly arose from a common trunk with theinternal pudendal artery (61.67%). Conclusion: The internal iliac artery exhibits significant anatomical variation in itsorigin, morphometry, and branching pattern. Knowledge of these variations is essential for surgeons and radiologistsperforming pelvic procedures to minimize the risk of vascular injury.