Endovascular Aneurysm Repair (EVAR) is a minimally invasive medical procedure used to treat a weakened and bulging section of the aorta, the body’s largest artery. This technique involves placing a specialized device, known as a stent graft, inside the affected artery. The stent graft reinforces the wall and redirects blood flow, stabilizing the aorta and preventing a life-threatening rupture.
The Condition EVAR Treats
EVAR addresses an aortic aneurysm, a localized enlargement of the aorta to more than one and a half times its normal diameter. The aorta is the main vessel that carries oxygen-rich blood from the heart down through the chest and abdomen. Aneurysms most frequently occur in the abdomen, known as an abdominal aortic aneurysm (AAA).
The aortic wall can weaken due to factors like high blood pressure, smoking, or genetic predisposition. Constant blood pressure causes the vessel wall to balloon outward. This progressive enlargement often continues for years without symptoms, meaning aneurysms are frequently discovered incidentally during unrelated medical scans.
The danger arises when the aneurysm reaches 5.5 centimeters or greater, significantly increasing the risk of rupture. A rupture causes massive internal bleeding and carries a high risk of immediate death. EVAR aims to eliminate the pressure on the weakened wall, thereby reducing the likelihood of this catastrophic event.
How the EVAR Procedure Works
The EVAR procedure is performed by vascular specialists using small incisions, typically made in the groin area. This minimally invasive approach contrasts with traditional open surgery, which requires a large abdominal incision. Thin, flexible tubes called catheters are inserted into the femoral arteries.
The surgeon uses live X-ray imaging (fluoroscopy) to guide the catheters to the precise location of the aneurysm in the aorta. One catheter contains the stent graft, a collapsible tube made of a metal mesh framework lined with durable synthetic fabric. This device is positioned within the aorta across the entire length of the aneurysm.
Once correctly placed, the stent graft is deployed and expands, anchoring itself firmly to the healthy aortic wall above and below the diseased segment. The fabric lining creates a new, sealed conduit for blood flow. This excludes the aneurysm sac from the main bloodstream, reducing pressure on the weakened wall and allowing the aneurysm to shrink.
Recovery, Follow-Up, and Potential Considerations
The primary benefit of EVAR is the significantly faster recovery compared to open surgical repair. Patients generally have a short hospital stay, often discharged within one to two days. Most individuals can resume light activities, such as walking, within a week, and return to normal activities typically occurs within two to four weeks.
Since the aneurysm sac remains in place and is bypassed, long-term monitoring is necessary to ensure the continued effectiveness of the repair. Patients undergo lifelong surveillance, involving routine clinical evaluations and periodic imaging studies. Computed tomography (CT) angiography is the preferred follow-up method to check the integrity and position of the stent graft.
A specific consideration is the potential for an “endoleak,” which occurs when blood bypasses the stent graft and re-enters the aneurysm sac. Type I and Type III leaks pose the highest risk of sac enlargement and rupture, often requiring immediate intervention.
Type II endoleaks are the most common, resulting from blood flowing backward from small side branches into the sac. These often resolve on their own and only require treatment if they cause the aneurysm to grow.
Another potential concern is stent graft migration, defined as the displacement of the device by more than 5 to 10 millimeters. Migration can compromise the seal and require a secondary procedure to secure the graft or extend the repair. Despite these long-term issues, the minimally invasive nature of EVAR provides a substantial short-term advantage in recovery.