Stent Graft Repair of an Abdominal Aortic Aneurysm

What is an abdominal aortic aneurysm (AAA)?

The aorta is the largest artery in the body. It carries blood from the heart to the rest of the body. The aorta is normally 2 to 3 centimeters in size. An aneurysm is a weakening in the vessel wall that results in dilatation, or “ballooning” of the vessel wall. If left untreated, an aneurysm may continue to grow and rupture, resulting in life-threatening bleeding. Aneurysms can occur anywhere in the body. An AAA occurs in the aorta between the kidneys and the pelvis. Small aneurysms rarely rupture, so your physician may decide that it is best to just monitor its development through periodic check-ups rather than repair the aneurysm. However, if the aneurysm continues to grow beyond 5.0 centimeters, your physician may recommend treatment.

How is an abdominal aortic aneurysm (AAA) treated?

Conventional Surgical Procedure
The open surgical approach involves making a large incision into the abdomen in order to expose the aorta and its aneurysm. Clamps are applied to the arteries above and below the aneurysm so that the artery may be directly cut open. The section of artery that is abnormally enlarged is replaced by a synthetic tube, which the vascular surgeon sews into place. The clamps are removed and blood flow is restored through the repaired artery. This operation has enjoyed durable success. However, it is a major surgery. There is an approximately 5% chance of fatal complications. The patient usually spends 7 to 10 days in the hospital and is not back to feeling like their regular self for 2 to 3 months.

Endovascular Stent-Graft Procedure

Recent advances in minimally invasive surgery have made the endovascular repair of an AAA possible. Stent-graft repair is usually performed by an Interventional Radiologist and Vascular Surgeon team in the operating room. The procedure is usually performed under general or spinal anesthesia. Incisions are made in each of the two groins, where the arteries at these locations are exposed. Under x-ray guidance, a delivery catheter (tube) containing a vascular graft iel in your leg into your aorta. At the tip of the catheter are a deflated balloon and a tightly wrapped cloth graft. When properly positioned, the graft is secured in place by inflating the balloon and opening the graft to the diameter needed to prevent blood flow into the aneurysm. The balloon is then deflated and removed along with the catheter. At each end of the graft are hooks that help secure it to the inner walls of the aorta. The graft allows blood flow to continue through the aorta to the arteries in the pelvis and legs, without filling the aneurysm.s guided up through a blood vess

Most patients remain in the hospital 1 -3 days following the procedure, and then require approximately 2 weeks recovery at home. The successful insertion of an aortic endograft has less operative stress on the body, no painful abdominal incision, less blood loss, a lower operative mortality, reduced length of hospital stay, and much faster recovery when compared to the open surgical approach. Over time, the aneurysm may shrink, minimizing future threat of rupture. However, there remains a 5-10% chance that the stent-graft may not adequately exclude all blood from flowing in the aneurysm. This is called an "endoleak". In these unusual occurrences, another catheter based minimally invasive procedure or other surgery may become necessary. Because of this, a more intensive follow-up is required. CT scans are periodically obtained. It is important that patients adhere to follow-up appointments with their doctor and have regular CT scans during the first year after the procedure to ensure that the stent-graft is properly positioned and effective.

What is an "endoleak" and how is it treated?

An "endoleak" is persistent flow into the aneurysm. There are several types of endoleaks, but the most common include a leak resulting from an incomplete seal of the stent-graft to the aortic wall, or due to opposing blood flow from collateral vessels. An incomplete stent-graft seal may be repaired by placing an additional expandable stent over this area to tack the loose stent-graft against the aortic wall. Collateral vessels may be embolized to block the blood flow to the aneurysm.