Stent Graft Repair

• How should I prepare for the procedure?
• What does the equipment look like?
• How does the procedure work?
• How is the procedure performed?
• What will I experience during and after the procedure?
• Who interprets the results and how do I get them?
• What are the benefits vs. risks?

In recent years, interventional radiologists have developed a treatment to repair an aneurysm without surgery. An small incision is made in the patient’s groin and a catheter (small tube) is inserted into a blood vessel that leads to the aorta. A stent-graft (a Dacron tube inside a metal cylinder) is inserted through the catheter. Watching the progress of the catheter on an X-ray monitor, the interventional radiologist threads the stent-graft to the weak part of the aorta where the aneurysm is located.           

With this technique, there is no need to make a large incision in the abdomen or to cut away the damaged section of blood vessel.

Once the stent-graft is in place, the metal cylinder is expanded like a spring to hold tightly against the wall of the blood vessel. The blood will now flow through the stent-graft, avoiding the aneurysm, which typically shrinks over time.

A stent-graft is threaded into the blood vessel where the aneurysm is located. The stent graft is expanded like a spring to hold tightly against the wall of the blood vessel and cut off the blood supply to the aneurysm.

Abdominal aortic aneurysm

Which Treatment Is Right For Me?

The best treatment for an abdominal aortic aneurysm (AAA) depends on a number of factors, including the size and location of the aneurysm, whether or not it is causing symptoms, and the age and general health of the patient. You should discuss all of these factors and any other questions you have with your primary care physician and VIA Interventional Radiologist to determine if you are a candidate for the non-surgical stent-graft repair procedure.

How Should I Prepare For The Procedure?

Blood tests are routinely ordered; you may have blood drawn at the hospital or a nearby clinic. You may be instructed to temporarily stop taking certain medications such as those that thin the blood. If you have diabetes it may be necessary to alter your insulin dose on the day of your procedure. The radiologist or a staff person will ask you to sign a consent form that covers the diagnostic and treatment procedure(s) that will be performed.

Make sure that the radiologist knows if you have any allergies so that special precautions can be taken. You will be asked not to eat solid foods after midnight, but may take clear liquids. Smoking is to be avoided the day before the procedure. Shortly before starting, the area where the catheter is to be inserted will be shaved and washed with antibacterial soap to prevent infection. In addition, you will have a tube placed into a vein in the arm or hand to receive fluids and medicines as needed. The intravenous (IV) line is used to give a sedative to help you relax and possibly make you drowsy. It will stay in place until your procedure is completed.

What Does The Equipment Look Like?

Your procedure will be monitored as it takes place using high-resolution radiological imaging equipment. The imaging technique may include X-ray, angiography and/or ultrasound.

The stent-graft repair equipment includes a catheter (small tube) and stent-graft (a Dacron tube inside a metal cylinder). Stent-grafts come in varying sizes so that in each case it matches the size of the diseased artery.

How Is The Procedure Performed?

stent-graft

The stent-graft repair is performed using either local or general anesthesia. Before the procedure, a number of diagnostic tests are performed. These diagnostic tests allow the doctor to visualize the aneurysm and the surrounding area. To prepare for the procedure, a small incision is made in each upper thigh area. Using visual guidance, the catheter is advanced through the large blood vessel in your thigh to the aneurysm site in your abdomen. When the catheter is properly positioned inside the aneurysm, the stent-graft is released from the catheter into the blood vessel. When the stent-graft comes into contact with blood, it expands to a preset size. After expansion of the stent-graft, the catheter is withdrawn and removed. Depending on the shape and size of your aneurysm, additional stent-grafts may be placed to assure that the aneurysm is completely reinforced. X-rays and/or ultrasound imaging procedures are performed to allow the doctor to verify that the stent-graft is properly placed within the aneurysm. The procedure typically takes between two to four hours to complete.

What Will I Experience During The Procedure?

When you receive a sedative through the IV line in preparation for the procedure, you will feel relaxed and sleepy but probably will stay awake throughout the procedure. There should be no pain when the catheter first is inserted into the groin artery, but you may notice slight pressure. You may feel pain briefly in the part of your body closest to the site of the aneurysm. After removing the catheter, a sandbag may be placed on the groin area to prevent bleeding.

What Can I Expect After The Stent-Graft Repair Procedure?

Patients have reported feeling some discomfort for the first few days following the procedure. Immediately after recovery from the procedure, your physician may require you to lay flat for four to six hours to allow the leg wounds to begin healing. You may experience side effects such as swelling of the upper thigh, numbness of the legs, nausea, vomiting, leg pain or throbbing, malaise, lack of appetite and/or absence of bowel movement for one to three days. Most patients will be able to walk about 6 to 8 hours after the procedure. Most patients return home in 2-3 days.

On returning home you should take it easy, avoid driving for 24 hours, and drink plenty of fluids. You should avoid strenuous exercise for at least two days. It is best not to take a hot bath or shower for the first 12 hours, and to avoid smoking for 24 hours or longer. If bleeding begins where the catheter was inserted, you should lie down, apply pressure to the site, and have someone call your doctor right away. Any change in color or a warm feeling in this area are also signs that something is wrong, as is pain in the area where the stent-graft was installed.

You may be asked to take aspirin or another anti-platelet drug indefinitely. MR imaging should be avoided for a month unless a radiologist approves the study. Metal detectors will not affect the stent-graft.

Who Interprets The Results And How Do I Get Them?

The radiologist judges the technical results of stent-graft repair by comparing pre- and post-procedure images of the area of the aneurysm. The patient can be told of the technical result as soon as the procedure is completed, though it is best to wait until the sedative has worn off. The clinical outcome may take longer to gauge.

What Are The Benefits Vs. Risks?

Benefits

• According to a national study conducted at medical centers throughout the United States, interventional radiology stent-graft repair of abdominal aortic aneurysms has fewer complications than surgery. Any of the complications that can occur after the conventional surgery can also occur after stent-graft repair, but they occur much less frequently. Because of this, there is less risk with stent-graft repair.
• Stent-graft repair allows people to be back on their feet in less time. Their average recovery time was 11 days, compared to 47 days with surgical repair.
• When the procedure is done without complications, it is much less stressful on the body.
• Patients undergoing stent-graft repair experienced less blood loss, fewer blood transfusions and a reduction or elimination in the amount of time that blood flow is decreased to vital organs and lower extremities.
• Patients undergoing stent-graft repair also experienced fewer (or no) days in the hospital intensive care unit.
• Interventional Radiology stent-graft repair requires less or no general anesthesia and mechanical ventilation.

Risks

• Stent-graft repair is a relatively new way to treat abdominal aortic aneurysms. It was first done in humans in 1991. It is now a quickly growing alternative to open surgery to correct AAAs. Because the procedure is relatively new, medical science is still to learn long term results with stent-graft repair. Also, short-term complications have not been studied as well as they have been with conventional surgery. The incidence of complications is less well known with stent-graft-repair.
• The procedure poses more risk for patients with severe heart and lung disease, as it is possible for complications to arise due to their existing health condition.
• In some patients, the stent-graft can develop a leak that can allow the aneurysm to resume growth and put the patient at risk for subsequent rupture. Almost all of these leaks can be fixed with minimally-invasive catheter-based-techniques, thus avoiding open surgery in almost all cases.
• In some patients, the stent-graft will migrate or slip out of position. This condition usually requires open surgery to repair, but happens much less often (about 1% of patients after two years).
• Because of these potential risks, all patients who have undergone stent-graft repair should be monitored with an ultrasound, plain x-ray of the abdomen, or a CAT scan every three to six months for the first two years, and probably once every 6 to 12 months thereafter.