Impact of Endoluminal Treatment on Small Abdominal Aortic Aneurysm: Aneurysm Sac Regression and Secondary Interventions With 5 Years of Follow-up

Abstract

Conclusion: Endovascular intervention for small abdominal aortic aneurysms (AAAs) does not result in faster aneurysm sac regression or lower rates of secondary intervention. Summary: It has been suggested endovascular repair be applied to small AAAs in an attempt to reduce secondary intervention rates associated with endovascular repair of larger AAAs. The authors reviewed 374 patients who underwent endovascular AAA repair between 1996 and 2006. Of these patients, 75 (20%) had a small AAA defined by an aneurysm sac diameter to aortic diameter ratio of <2 at the level of the renal arteries, and 299 patients had larger AAAs. There were no significant differences in operative times or operative blood loss in patients undergoing endovascular repair for small AAAs vs those undergoing repair of larger AAAs. In the patients treated for small AAAs, 25.3% developed endoleaks compared with 36.1% of patients treated for larger AAAs (P = .1). Over a mean follow-up of 42 months (range, 1-109 months), 11 patients (14.7%) with small AAAs had secondary interventions. Of the patients with larger AAAs, 58 (19.4%) had secondary interventions (P = .41). At 5 years, small AAAs had a 2.5% regression in the aneurysm sac volume but a 3.0% increase in aneurysm diameter. Patients with large AAAs had slight increases in sac diameter (3.3%) at 1 month but steady decreases in sac volume (–13.4%) and aneurysm diameter (–8.8%) over 5 years. Comment: The data argue against early intervention with endovascular techniques for small AAAs. Previous data from the University of Texas Southwestern Medical Center suggests waiting for small AAAs to enlarge to 5 to 5.5 cm does not reduce the applicability of endovascular techniques for their repair. Given those data, the relatively benign natural history of small AAAs, and the data presented here, it seems difficult to justify repair of small AAAs with endovascular techniques outside the context of a clinical trial.