Definition & Overview
The iliac artery is a group of three arteries (common, external, and internal) located in a region called the ilium in the hipbone (pelvis). Ilium is the large broad bone, which forms the upper part of each half of the hipbone.
The common artery, which forms at the terminal portion of the aorta, divides into two to produce the external and internal iliac. The external iliac continues down the groin to form the femoral artery. The internal iliac, on the other hand, continues to the perineum (the area between the anus and scrotum) and the sexual organs.
Any blood vessels in the body can suffer from trauma, infection, or malformation. One such condition is an aneurysm, which refers to the enlargement of an artery due to the weakening of the arterial wall. Aneurysms are uncommon, affecting just 0.03% of the population. The condition can be treated with endovascular repair surgery.
Who Should Undergo and Expected Results?
The endovascular repair of an iliac artery is indicated for iliac artery aneurysms. The goal of the treatment is to keep the arteries from rupturing.
The common iliac artery (CIA) is the one that is commonly impacted in the iliac artery system. Aneurysms in this area are difficult to examine because they lie deep in the pelvis. They are usually discovered accidentally when another examination for another condition is being performed in the area. Because of this, patients usually present themselves in the hospital with an already ruptured artery.
The risk of iliac arteries from rupturing because of an aneurysm is based on the rate of growth of the aneurysm and its current size. There are, however, some exceptions.
The CIA is considered aneurysmal when its size reaches 1.5cm. It is important to note that ruptured iliac arteries, especially the common iliac artery, measure between 7 and 8 cm. However, there are reports of CIA rupturing at only around 3.55cm (such cases are very rare). Surgeons conduct repair as soon as iliac artery aneurysms reach 3cm in size to prevent complications.
The growth of an aneurysm in this artery system depends on its current size. Smaller aneurysms tend to increase in size slowly, averaging 1.1 mm/year. Those that are already 3cm grow at an average of 2.6 mm/year. If the patient was diagnosed with an aneurysm that is smaller than 3cm, doctors can prescribe medicine or other alternative treatments to keep it from rupturing. On the other hand, if the size of the aneurysm is at least 3cm, doctors begin repair almost immediately after conducting all the needed medical tests.
Endovascular treatment for iliac artery aneurysms is very effective compared to open surgeries. Because it is less invasive, patients can go home a day or two following the procedure. The majority of patients do not suffer from immediate complications. Morbidity and mortality rates are also low. As such, it is preferred by many surgeons in almost all cases of iliac artery aneurysms.
The right selection of patients and performing correct pre-operative tests, such as angiography and routine contrast-enhanced spiral CT scans, are keys to the success of the procedure.
How is the Procedure Performed?
Endovascular repair surgery is a modern, minimally invasive approach to treating clogged or diseased arteries due to an aneurysm. It involves making an incision near the hipbone to access the iliac arteries. Endovascular refers to any surgical procedure where a flexible catheter is inserted through the skin (percutaneous) to reach the affected blood vessel.
The catheter contains the necessary medicine and other miniature instruments that are used to treat the diseased blood vessel. An ilio-iliac tube endoprosthesis is implanted in the iliac region to provide temporary support while the treated diseased blood vessel heals.
Heparin is administered before the procedure to avoid blood clots. The patient will also need to take heparin at least two weeks before the procedure to ensure that coagulation will not occur while the body is recovering.
The patient is required to visit the hospital for a follow-up checkup after the procedure. During the visit, diagnostic tests, such as angiogram, will be performed.
Possible Risks and Complications
Open surgical treatment for iliac artery aneurysms is risky as it can cause rapid bleeding. It has a high rate of morbidity (incidence and prevalence of the disease) and mortality (the measure of death in a given population). This is the reason why repair through endovascular means (sometimes using tube ilio-iliac endoprosthesis) is typically the first option among surgeons in many hospitals worldwide.
Although safe, the procedure comes with risks and possible complications. These include transient bowel ischemia (more on intestinal ischemia, the flow of blood in major arteries of the intestine stops) and blockage (embolus) in the arteries. However, this can be treated almost immediately with appropriate medicines or similar non-invasive endovascular treatments.
To ensure that patients do not suffer from post-operative complications, sequential contrast-enhanced spiral CT scanning is performed after 6, 12, and 24 months following the procedure.
Any symptoms, such as nagging pain that does not go away, should be reported to the surgeon immediately.
Erin H. Murphy, MD, and Edward Y. Woo, MD; “Endovascular Management of Common and Internal Iliac Artery Aneurysms” http://evtoday.com/2012/03/endovascular-management-of-common-and-internal-iliac-artery-aneurysms/
AHA Journals; “Treatment of Iliac Artery Aneurysms by Percutaneous Implantation of Stent Graft”; http://circ.ahajournals.org/content/102/suppl_3/Iii-253