Comparison of Surveillance Versus Aortic Endografting for Small Aneurysm Repair

Randomized Clinical Trial Comparing Surveillance and Selective Surgical Treatment for Abdominal Aortic Aneurysms Less Than 5.5 cm in Diameter Versus Early Endovascular Treatment

Objective of the present study is to compare endovascular repair versus surveillance and, eventually delay treatment in patients with small abdominal aortic aneurysms (AAA), with respect to patient survival, AAA rupture and AAA related death risks.

The study will include patients with small AAA (diameter 4.1 to 5.4 cm defined by Computed Tomographic scan) suitable for endovascular repair (EVAR).

Randomization is designed with equal probability of assignment to each of the two groups (ie, immediate endovascular repair or surveillance group) by means of a computer-generated -random-number list . After eligibility is verified, assignment will be made using a computer database held at the Coordinating Centre.

In the immediate repair group, endovascular repair with introduction of an aortic endograft (Cook Zenith) will be performed within six weeks from randomization.

In the surveillance group, patients are followed without repair until the aneurysm reaches 5.5 cm in diameter, or enlarges at least 1.0 cm in one year, or until patient develops symptoms that are attributed to the aneurysm by the attending investigator. When one of these criteria is met, endovascular repair (if the patient remains a candidate for EVAR), or open repair will be carried out.

Inclusion Criteria:

• Patients of 50-80 years of age
• Non symptomatic infrarenal AAA of 4.1 to 5.4 cm in diameter measured by CT performed within 3 months before randomization
• Adequate infrarenal aortic neck (length > 15 mm diameter < 30 mm) and other anatomical configurations suitable for EVAR
• Patients have a life expectancy of at least 5 years
• Signed informed consent

Exclusion Criteria:

• Ruptured or symptomatic AAA
• AAA maximum diameter >= 5.5 cm
• Suprarenal or thoracic aorta aneurysm of more than 4.0 cm
• Patient unsuitable for administration of contrast agent
• Severe heart, lung, liver or renal disease (serum creatinine >= 3mg/dl)
• Need for adjunctive major surgical or vascular procedures within 1 month
• High likelihood of non compliance with follow-up requirements