Renal perfusion defects after endovascular repair of abdominal aortic aneurysms

To determine the prevalence of new renal perfusion defects and the association of these events with aneurysm neck atheroma during endovascular stent-graft repair of abdominal aortic aneurysm (AAA).

A retrospective review was performed of 50 patients who underwent AAA repair with bifurcated endovascular stent-grafts without suprarenal components between June 1998 and May 1999. Pre- and postprocedural computed tomographic (CT) angiograms were reviewed to determine the prevalence of new renal perfusion defects. The percent volume of atheroma of the aneurysm neck was determined by three-dimensional volumetric reformation and correlated with prevalence of new postprocedural renal perfusion defects. Follow-up CT angiography was performed between 6 months and 2 years after the procedure and used to evaluate the presence of residual defects and interval changes.

Of 50 subjects, 18% (n = 9) had new perfusion defects presumed to be embolic in origin. Follow-up was available for four patients: scarring and cortical thinning consistent with infarction developed in two, whereas the defects resolved in the other two. Analysis of aneurysm neck revealed an average percentage of atheroma of 32% and a range of 0%-73%. In subjects with >/=40% neck atheroma, the prevalence of new renal perfusion defects was 45.4% (five of 11), compared to 10.3% (four of 39) in subjects with <40% neck atheroma. This difference was significant (P =.0170).

In this series, the frequency of renal embolic events associated with AAA endovascular repair was 18%. Prevalence of renal embolic perfusion defects was shown to correlate with volume of aneurysm neck atheroma.