Aortic Aneurysm Repair - Endovascular Aneurysm Repair

What is endovascular aneurysm repair?

Endovascular aneurysm repair is a newer alternative to surgical aneurysm repair to prevent an aortic aneurysm from bursting. During endovascular aneurysm repair, a fabric and wire mesh tube (called a stent graft) is used to strengthen the aorta wall from the inside. The stent graft absorbs the pressure of blood flowing through the aorta, preventing it from pressing on the aneurysm and causing it to enlarge or burst. With time, the aneurysm usually shrinks.

Placement of a stent graft in an abdominal aortic aneurysm.
A: a catheter is inserted into an artery in the groin and guided to the abdominal aorta, and the stent graft is released.  B: the stent reinforces the artery walls and allows blood to flow through the aneurysm, preventing it from rupturing.

Because the procedure is endovascular ("inside the blood vessels"), it does not require opening the body. Instead, the stent graft is carried on a long thin tube called a catheter that is inserted into your arteries through a small incision in the groin. Once it reaches the aorta, the stent graft is expanded and the catheter is removed.

Endovascular repair is becoming increasingly common because it is safer than surgical repair for both women and men, and allows you to recover faster with less pain. In some states, endovascular aneurysm repair accounts for more than half of aneurysm repair procedures.⁸ However, endovascular repair is not right for everyone, and some aneurysms can only be treated with surgery because of their size or location.

How do I prepare for the procedure?

Be sure your doctor knows about all medications you are taking, including prescription medication, over-the counter drugs, and any dietary or herbal supplements. Some medications, such as the blood-thinning drugs warfarin (Coumadin), clopidogrel (Plavix), and aspirin can increase your risk of bleeding, and you may be told to stop taking them a few days before the procedure.

You will have standard tests including blood and urine tests, an electrocardiogram (ECG), and a chest-X-ray to give your surgeon the latest information about your health. These may be done a few days before the procedure or after you are admitted to the hospital.

You should not eat or drink after midnight the night before the procedure. If you have diabetes, ask your doctor how to keep your blood sugar under control before and after the procedure. Your doctor may give you other special instructions.

What happens during the procedure?

Endovascular aneurysm repair takes place in special operating room called a catherization lab. You will be placed on a stretcher and given a mild sedative to help you relax. A nurse will insert an intravenous (IV) line into a vein in your arm so that medications can be given during the procedure. The area near your groin where the catheter is inserted will be washed, disinfected, and shaved if necessary. Endovascular aneurysm repair is usually performed using regional or local anesthesia, so you will be awake but will not feel pain.

The operator will make a small incision above the femoral artery in your groin, near the crease where your leg meets your abdomen. A thin metal wire called a guide wire will be inserted into the artery and guided up to your aorta using X-ray images. The doctor will then use a long, thin tube called a catheter, which follows the guide wire, to carry a stent graft up to your aorta. The stent graft is a fabric tube inside a wire mesh cylinder that is shaped like your aorta and designed to reinforce the aorta's walls. As the catheter is pulled back, the stent graft expands like a spring to fit tightly against the aorta wall above and below the aneurysm.

Blood passing through the aorta flows inside the stent graft, instead of pressing on the aneurysm and causing it to expand or burst. With time, the aneurysm usually shrinks because the pressure of blood pumped from the heart is no longer forcing it to balloon outwards.

After taking X-rays to make sure the stent graft is in place and no blood is leaking around the edges, the guide wire will be removed and the incision in your groin will be closed.

What happens after the procedure?

After the procedure you will be transferred to a recovery room where your breathing, blood pressure, and other vital signs will be continuously monitored. The incision where the catheter was inserted will be checked for bleeding, swelling, or infection. You should expect to stay in the hospital for 3 to 4 days after endovascular aneurysm repair, compared with 7 to 10 days after surgical repair.⁸

When you leave the hospital, you will be given instructions about how to care for the incision wound and you may have to take blood-thinning medications (such as aspirin) to prevent clots. You should avoid taking baths until your incision is fully healed, and avoid heavy lifting and strenuous activity for 4 to 6 weeks. Contact your doctor immediately if you notice:

• Signs of infection such as fever or chills, or redness, swelling, or increasing pain where the catheter was inserted
• Cough, chest pain, or shortness of breath
• Pain or swelling in your abdomen
• Signs of blood clots in the legs, such as pain and swelling

You will return for a follow-up visit about a month after the procedure. You will need to have imaging tests (such as ultrasound or a CT scan) at one and six months after the procedure to make sure your stent graft is in the proper position and blood is not leaking into the aneurysm. If these initial tests are normal, your doctor will probably want to check the graft once a year to watch for any long-term changes.

What are the risks of the procedure?

As with all procedures, endovascular aneurysm repair carries some risks. However, it is generally safer than surgical repair, and less than 3% of patients die in the hospital following the endovascular procedure.⁸ Perhaps because of their smaller arteries, women are more likely to experience complications during the procedure than men are (31% of women versus 13% of men), but they are no more likely to die or need additional procedures to treat their aneurysm.^9-11 For both women and men, endovascular aneurysm repair carries a lower risk of complications than surgical aneurysm repair.

Potential complications after endovascular aneurysm repair include:

• Leaking of blood around the graft and into the aneurysm, known as "endoleak"
• Failure of the graft to close off the aneurysm, requiring a surgical aneurysm repair (less than 1% of patients)
• Movement of the graft away from where it was placed
• Splitting or breaking of the stent graft
• Blood clots that can cause a heart attack, stroke, or DVT
• Infection of the incision where the catheter was inserted

References

1. Hirsch AT, Haskal ZJ, Hertzer NR, et al. ACC/AHA 2005 Practice Guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): a collaborative report from the American Association for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease): endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation. Circulation. Mar 21 2006;113(11):e463-654.
2. Brewster DC, Cronenwett JL, Hallett JW, Jr., Johnston KW, Krupski WC, Matsumura JS. Guidelines for the treatment of abdominal aortic aneurysms. Report of a subcommittee of the Joint Council of the American Association for Vascular Surgery and Society for Vascular Surgery. J Vasc Surg. May 2003;37(5):1106-1117.
3. Mani K, Bjorck M, Lundkvist J, Wanhainen A. Improved long-term survival after abdominal aortic aneurysm repair. Circulation. Jul 21 2009;120(3):201-211.
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5. Dardik A, Lin JW, Gordon TA, Williams GM, Perler BA. Results of elective abdominal aortic aneurysm repair in the 1990s: A population-based analysis of 2335 cases. J Vasc Surg. Dec 1999;30(6):985-995.
6. Heller JA, Weinberg A, Arons R, et al. Two decades of abdominal aortic aneurysm repair: have we made any progress? J Vasc Surg. Dec 2000;32(6):1091-1100.
7. Starr JE, Hertzer NR, Mascha EJ, et al. Influence of gender on cardiac risk and survival in patients with infrarenal aortic aneurysms. J Vasc Surg. May 1996;23(5):870-880.
8. Anderson PL, Arons RR, Moskowitz AJ, et al. A statewide experience with endovascular abdominal aortic aneurysm repair: rapid diffusion with excellent early results. J Vasc Surg. Jan 2004;39(1):10-19.
9. Abedi NN, Davenport DL, Xenos E, Sorial E, Minion DJ, Endean ED. Gender and 30-day outcome in patients undergoing endovascular aneurysm repair (EVAR): an analysis using the ACS NSQIP dataset. J Vasc Surg. Sep 2009;50(3):486-491, 491 e481-484.
10. Wolf YG, Arko FR, Hill BB, et al. Gender differences in endovascular abdominal aortic aneurysm repair with the AneuRx stent graft. J Vasc Surg. May 2002;35(5):882-886.
11. Ouriel K, Greenberg RK, Clair DG, et al. Endovascular aneurysm repair: gender-specific results. J Vasc Surg. Jul 2003;38(1):93-98.