An aneurysm is a dilated section of a blood vessel, caused by weakening of the vessel walls at that point. If aneurysms grow too large there can be a danger that they will rupture, causing potentially fatal internal bleeding. For this reason, what is called an aneurysm graft may be used to repair a blood vessel considered to be at risk of bursting. An aneurysm graft consists of a tube of synthetic material, either woven or knitted, supported by a metal structure which is shaped to resemble a healthy version of the section of blood vessel to be repaired. A surgical procedure is carried out where the damaged vessel is rebuilt using the aneurysm graft, and this is sometimes carried out as an emergency operation in cases where a previously undiagnosed aneurysm has ruptured.
Aneurysms most commonly occur in the aorta, which is the largest artery in the body. The aorta runs up from the heart to form the aortic arch, before curving down and passing through the chest and abdomen. Since an arterial aneurysm can occur at any one of a number of locations along the aorta, symptoms may vary, and in most cases there are no symptoms at all. Sometimes pain in the abdomen or back may be experienced, and occasionally an aneurysm appears as a pulsating abdominal swelling. In the case of a ruptured aneurysm, there could be sudden, severe pain and the person may collapse.
Traditionally, aortic repair using an aneurysm graft was carried out by open surgery, with a large incision being made to expose the aorta. More recently, a technique known as endovascular aneurysm repair has come into use, where the aneurysm graft, sometimes known as a stent graft, is inserted through an artery in the leg and passed up into the aorta. It is then moved along to the site of the aneurysm and a repair is carried out from inside the aorta. The shape of the graft may be a simple tube or it may branch to connect with the two femoral arteries which supply the legs.
In the case of aneurysms in other parts of the body, an aneurysm graft may not be the treatment of choice. For example, a brain aneurysm, where one of the cerebral arteries is dilated, is more likely to be treated using other surgical methods. A heart aneurysm, involving bulging of a coronary artery, may sometimes be treated using an aneurysm graft, as may a carotid aneurysm in one of the carotid arteries in the neck. Possible complications include the aneurysm graft leaking, moving out of position, or becoming kinked or blocked.