ABDOMINAL AORTIC ANEURYSM

ABDOMINAL AORTIC ANEURYSM

An increase in the diameter of an artery is called a dilatation and any dilatation more than 150% of its uninvolved adjacent segments is referred as an aneurysm. Generally, a dilatation of abdominal aorta beyond 3 cm (normal diameter being 2 cm) is accepted as an abdominal aortic aneurysm.

When an AAA has a diameter of more than 5 cm, especially one 5.5-6 cm or larger, the risk increases dramatically, and treatment becomes unavoidable.  For women the size criterion is 5 mm to 1 cm; treatment becomes necessary for them when the aneurysm diameter is a little smaller.  Hypertension, smoking, and chronic pulmonary diseases (bronchiectasis, emphysema, etc.) are among the risk factors.  Treatment of AAA involves either traditional open surgery or Endovascular Abdominal Aneurysm Repair (EVAR).  In open surgery, an incision is made in the patient’s abdomen, then the aneurysm is eliminated by removing the aneurysmal sac and suturing in a synthetic vessel to replace the damaged natural one.  In EVAR, the doctor repairs the aortic aneurysm by entering from a small incision in the groin and inserting a specially designed synthetic vessel called a stent inside the aneurysm, so that there is no longer any connection between the normally circulating blood and the aneurysmal sac.  The risk for open surgery is approximately 5%, even in the wider series that includes patients with advanced age and other risks.  These days, many patients are treated with EVAR, and open surgery is utilized for patients with anatomies unsuitable for EVAR.  This methodology involves less risk (2-3%) in the first 30 days.  An emergency open surgery may be required due to unexpected problems encountered during EVAR; however, this is rare.  Patients with successful EVAR are more prone to future surgeries compared with patients with successful open surgery.  It is found that the risk of death is less following EVAR, but after two years there is no difference in death rates when all-cause mortality is taken into account.  This finding is explained by the fact that patients with AAAs have many other concomitant diseases that carry risk of death. Therefore, risk factor management is absolutely necessary in order to improve optimal life expectancy in patients with treated AAAs.