Small Abdominal Aortic Aneurysms Should Not Be Treated Surgically

Patients with abdominal aortic aneurysms (AAAs) of less than 5.5 cm have no significant differences in clinical outcomes after endovascular repair (EVAR) than those with larger AAAs, according to a new study.

Researchers from Washington University School of Medicine (St. Louis, MO, USA) evaluated five-year data from 156 patients enrolled in the prospective Medtronic (Santa Rosa, CA, USA) Talent Enhanced Low Profile System (eLPS) trial; analyses were performed for patients with AAAs that measured less than 5.5 cm, and for those with AAAs larger than 5.5 cm. Aneurysm morphology, demographics, and perioperative endpoints were assessed. Safety and effectiveness endpoints were evaluated at 30 days, one year, and five years after the procedures.

The results showed there were no statistically significant differences between large or small AAAs in the rate of freedom from major adverse events (84.6% versus 75.8%) or freedom from aneurysm-related mortality (98.7% versus 96.8%) at one year; long term outcomes at 5 years also showed no difference. The researchers did find that small AAA patients had higher rate of successful aneurysm treatment at 12 months (96.8% versus 84.9%), defined by the study as the combination of technical success, absence of aneurysm expansion, and absence of reintervention for type I or type III endoleaks. The study results were presented at the 64th Vascular Annual Meeting of the Society for Vascular Surgery (SVS), held during June 2010 in Boston (MA, USA).

"The results confirm the intuitive notion that smaller AAAs have aortic neck characteristics that are more favorable for EVAR. However, the important take-home message is that there were no differences in long-term 5-year outcomes between the two groups,” said lead author and study presenter Jeffrey Jim, M.D., of the section of vascular surgery. "So our position remains that EVAR should not be routinely recommended for those with small AAAs.”

AAA is a localized dilatation (ballooning) of the abdominal aorta exceeding the normal diameter by more than 50%. Approximately 90% of abdominal aortic aneurysms occur infrarenally but they can also occur pararenally or suprarenally. Such aneurysms can extend to include one or both of the iliac arteries in the pelvis. The major complication of abdominal aortic aneurysms is rupture, which can be life threatening, as large amounts of blood spill into the abdominal cavity, and can lead to death within minutes.

Related Links:
Washington University School of Medicine
Medtronic