EVAR: Endovascular aneurysm repair. A procedure to repair an aneurysm of the aorta. In EVAR a stent is placed in the aneurysmal area of the aorta. The procedure is similar to the placement of a stent in a coronary artery after angioplasty.
An aortic aneurysm is a ballooning or widening of the aorta, the largest artery in the body. The aneurysm weakens the wall of the aorta and can end in the aorta rupturing with catastrophic consequences. As the diameter of the aneurysm increases, the chances of the aneurysm rupturing rise dramatically. Large aortic aneurysms are very perilous and can be silent, with few or no symptoms. Men over 60 are particularly at risk to have an aortic aneurysm.
EVAR is done percutaneously (through the skin). It usually involves two small incisions made in the groin to expose the femoral arteries. A synthetic graft and stents are fed through these arteries with catheters and guidewires until the graft is positioned correctly at the top and bottom of the defective portion of the aorta. Removal of the sheath with or without balloon expansion allows barbs or other fixing devices to attach to the artery wall and hold the graft firmly in place, allowing blood to pass through it and remove pressure from the weakened aortic wall.
Before the introduction of EVAR, aortic aneurysms were treated by open surgical repair, a major operation done under general anesthesia. It requires a laparotomy (an incision to open the abdomen) and clamping of the aorta (to shut off blood flow in it) for at least a half hour. Open surgical repair of an aortic aneurysm carries a 30-day mortality (death rate) of between 4 and 12%. However, the grafts are durable for 20-30 years and function effectively in most patients for the rest of their lives.
EVAR was invented in the early 1990s by surgeons in the Ukraine and Argentina as a less invasive endovascular method of repair of an abdominal aortic aneurysm (AAA). Improvement of the devices and development of the technology led EVAR to be used worldwide.
With large AAAs, EVAR reduces the 30-day operative mortality by two-thirds compared with open surgery. Thus, EVAR is superior in terms of saving lives. However, there is a tradeoff because a further procedure is more often needed after EVAR than after open surgery.