Informational Guide to Endovascular AAA Repair (EVAR)
This article is for you if your vascular surgeon has advised EVAR for the surgical repair of your aneurysm. Answers to most of your questions are present in this article.
What is an Abdominal Aortic Aneurysm?
Aorta is the largest artery that supplies blood to every part of your body through its multiple branches. The aorta descends after leaving the heart and passes through your thorax and abdominal region. The part of the aorta inside the thorax is called the thoracic aorta. The part present in the abdomen is called the abdominal aorta.
The abdominal aorta supplies your lower trunk and divides into two major branches that supply your legs. Sometimes, the abdominal aorta wall becomes weak and less elastic due to multiple damaging factors. In addition, the blood pressure causes the wall to bulge outward, forming a swelling called an abdominal aortic aneurysm.
What are the Indications for Surgical Treatment?
The normal abdominal aorta has a diameter of 1.4 cm to 3.0 cm. AAA is a swelling that is more than 3.0 cm in size. The size of the aneurysm is usually directly related to the risk of rupture. Aneurysmal rupture is a devastating condition as it leads to severe bleeding.
Your vascular surgeon will recommend surgical treatment under the following conditions.
- If your aneurysm is more than 5.5 cm in size
- If the aneurysm is rapidly growing
- If the aneurysm is painful and you are also showing persistent symptoms of the disease
- If you have an abnormal shape of aneurysm that has a high risk of rupture
- In an emergency, if there is a rupture of the aneurysm
What are the Options for Surgical Treatment?
Surgical treatment of AAA involves the placement of a synthetic graft in place of the defective vessel. This allows the artery to maintain its function more effectively. Surgeons use a few different surgical techniques for the placement of the graft.
- Open repair involves opening your abdominal cavity to locate the aneurysm. Next, the vascular surgeon stitches the graft into the place of the aneurysm. He finally closes the abdomen and applies stitches on the wound.
- Endovascular Repair (EVAR) is a treatment method in which your surgeon inserts a graft into the aneurysm via a vessel in your groin. It is a less invasive technique that promotes rapid healing. However, you will need multiple follow-up scans after surgery to check the stent position and the size of the treated aneurysm, usually every six months or yearly.
- Complex Endovascular Repair of AAA: Complex endovascular repair involves procedures like fenestrated repair or branched repair.
What Does the Complex Endovascular Repair of AAA Involve?
Fenestrated endovascular repair or FEVAR helps in the surgical repair of AAA with a short infrarenal neck. In such cases, arteries to the kidney usually arise from the aneurysm or very close to it. Your vascular surgeon places the graft through the vessel in your groin while preserving the blood supply to the kidneys and other organs.
Branched endovascular repair is helpful for the restoration of the aneurysmal sac along with its branches.
Under What Conditions Will You Need EVAR?
Both open repair and EVAR have their benefits and drawbacks. Your vascular surgeon critically assesses your condition and advises the best surgical method. He will tell you everything about the treatment and let you decide whether you want the surgery or not. A final decision will be entirely yours.
You are suitable for EVAR under the following conditions,
- If you have other diseases that may complicate the conventional method of open repair
- If you have proper anatomy of the aorta and its major vessels. You need to have a long enough section of a normal artery for the stent graft to attach securely
Are There Any Tests Required Before Surgery?
Your vascular surgeon will take your complete medical history related to your disease and medications. He will also perform a thorough physical examination to know more about your circulation and other medical condition. After these preliminary protocols, he will advise you on some tests to assess your fitness for surgery and which intervention is appropriate for your AAA.
CT Scan: It helps determine the condition of the aneurysm and surrounding vessels. It also helps decide which shape and size of the graft your vascular surgeon will require
What Happens During the Surgery?
Before surgery, your anaesthetist will discuss your options with you. EVAR can be performed by injecting local anaesthesia to your groin or by injection in your back and under general anaesthesia, depending on your fitness and the complexity of the surgery.
Your vascular surgeon first cleans the access site on the skin using a particular chemical that reduces the risk of infections. Next, your vascular surgeon will make a small incision in your groin near the artery that supplies the thigh, the femoral artery.
Using a special catheter, he will insert a dye into the artery to make it visible on an X-ray machine. Then he will pass the guidewire through the femoral artery to the aneurysm. You will not feel pain during the process, as you don’t have any nerves in your artery
Your surgeon will then insert the stent graft under X-ray guidance. At the desired location, the graft will slightly expand. This expansion helps the graft to remain fixed in its place.
What Happens After EVAR?
After successful surgery, you must rest in bed for a few hours to reduce the risk of groin bleeding, and then you will be able to walk. After a few hours of the intervention, you will be able to eat. You will be required to stay in the hospital from 24 hours to 72 hours for monitoring. Your surgeon will usually advise you to do light walking every day and avoid lifting heavy objects. You must wait a few weeks before lifting anything heavy and refrain from driving your car until you feel no pain in your groin while driving.
When Will You Go for Follow-up?
In the case of EVAR, you need long term follow-ups than open surgical repair. The first follow-up few weeks after the surgery. Your doctor will examine your wound to look for any signs of infection. He will also assess your overall health to look for signs of postoperative complications during this visit.
Your vascular surgeon will arrange imaging testing ultrasound or CT scan to determine the functioning of your stent graft. Scans also indicate whether your graft is in an ordinary place and if any blood is leaking outside your stent to your aneurysm. Usually, you will have to visit your doctor every year to evaluate your stent with a new scan. However, you have to see your surgeon more frequently if he advises
What are its Possible Complications?
EVAR is a less invasive procedure and presents with less risk of complications than conventional open surgical repair. However, you are at risk of some complications and require long term follow-up:
- Endoleaks: Sometimes, blood leaking occurs from the graft. The blood gets pooled up in the aneurysm sac and causes it to swell again. In most cases, leaks are not significant but sometimes require reintervention for proper control.
- Vessel problems: Bleeding from the groin or injury to one of the main arteries in your abdomen. This risk is low, usually about 1% of the patients.
- Kidney Problems: In EVAR, your doctor uses a dye to make your vessels visible to the X-ray machine. After the surgery, the dye gets cleared through the kidneys. People who already have kidney problems are at higher risk as the dye has the potential to damage the kidneys
- Heart disease: AAA patient usually has some underlying heart disease. Life-threatening conditions such as heart attacks may happen after the intervention.
- Chest Infections: There are chances of chest infections after the endovascular repair of the aneurysm.
- Other severe but rare complications: leg paralysis, blocked blood flow to your abdomen or lower body, graft infection, and delayed AAA rupture.
Your vascular surgeon will explain to you in-depth your own risk and benefits of surgery.
What Are Endoleaks?
Sometimes, blood leaks into the gap between the graft and the aneurysmal sac. Blood is not leaking or bleeding into the abdominal cavity. They are common to happen after endovascular aneurysmal repair.
In most cases, endoleaks are minor and resolve spontaneously. While in a few others, you would need another intervention to prevent further complications. Endoleaks can occur even years after the procedure. Therefore, regular follow-ups are important to avoid this complication.
What Are Different Types of Endoleaks?
Depending upon the leakage area, endoleaks are classified into four main types.
- Type I: When the blood leaks from the attachment site of the graft with the vessel wall
- Type II: When there is a filling of the aneurysmal sac with blood via a branch artery
- Type II: When there is a filling of the aneurysmal sac with blood via a branch artery
- Type IV: In such cases, the graft becomes highly porous and allows the blood to leak through the graft
Your vascular surgeon will explain your treatment options and surgical risks in detail.
