Step-by-step ligation of the internal iliac artery

The internal iliac artery is the main vascular supply of pelvic visceral structures. All pelvic surgeons must know the anatomic landmarks and basic steps of internal iliac artery ligation in order to stop massive pelvic hemorrhage. This cadaveric demonstration and clinical review of the internal iliac artery shows the anatomic landmarks and basic steps of internal iliac artery ligation.


Introduction
The anatomy of the internal iliac artery (IIA) has been well documented previously and it is the major blood supply of pelvic structures. It arises from the common iliac artery and runs infero-medially in the pelvis. An enormous number of small vessels, collateral circulation, and variations exist in pelvic vasculature (1,2).
The role of IIA ligation to control intractable pelvic hemorrhage has been described by Kelly (3) for the first time in 1893 for a cervical carcinoma case. Ligation of the IIA could also be a lifesaving procedure during peripartum bleeding (4,5). In selected cases, ligation of IIA is also an option during intraperitoneal bleeding where the exact location could not be identified because IIA is the main blood supply of the pelvic viscera (6).
During a massive pelvic hemorrhage or peripartum bleeding, bilateral ligation of the IIA reduces the pelvic arterial blood flow by 49% and pulse pressure by 85% (7). After bilateral ligation of IIA in the long term period, the collateral circulation will maintain the re-functioning of the IIA. The deep femoral artery is the principal vascular supply to provide re-vasculature to the IIA. Anastomosis between the medial femoral circumflex and obturator artery, and the lateral femoral circumflex and superior gluteal artery are the main connection areas (8). Additionally, the ovarian artery also provides blood flow to the uterus. Despite bilateral ligation of the IIA, future reproductive potential is not affected totally and term pregnancies have also been reported in the literature (9,10).
Despite some technical difficulties with regard to anatomic relationships and potential complications, ligation of IIA provides a rapid way to decrease the pelvic arterial blood flow. This clinical and photographic review shows the step-by-step surgical technique used in ligation of the IIA because all pelvic surgeons need to know how to ligate the IIA.

Probable indications of internal iliac artery ligation
Ligation of the IIA has a proven success rate in controlling massive pelvic hemorrhage, varying between 40% and 100%, and obstetric pathologies occupy the first place as the leading factor (11,12). Table 1 shows the obstetric and gynecologic indications of IIA ligation.

Probable complications during ligation of the internal iliac artery
The risk of operative injury beyond success is the major gap beneath the feasibility of the procedure ( Table 2). A detailed knowledge of the anatomy is required along with good exposure to achieve the procedure with the maneuver of traction and counter-traction. Bilateral ligation of the IIA is better to control the total blood flow in the pelvis and the surgeon would prefer to change the operative side for a comfortable surgical practice.

Basic anatomy of the internal iliac artery
The aorta is divided into left and right common iliac arteries at the level of the fourth and fifth lumbar vertebra (L4-5) and after a pathway of 4.0-5.0 cm the common iliac artery gives the

Clinical tips
Monopolar or bipolar electrocoagulation could also be used during dissection of the surgical field, bleeding from small veins will stop spontaneously; nevertheless, care must be taken. Before ligation of the IIA, dissection of the ureter is extremely important and inspection is better than just palpation of the ureter in the context of preventing any probable injury. Although ligation of IIA could be performed at any side of the patient either right or left, the surgeon must be careful during dissection and traction of the IIA because movement of the right-angle clamp from medial to lateral will cause a laceration on the external iliac vein.