Increased incidence of renal cysts in patients with abdominal aortic aneurysms: a common pathogenesis?

We have empirically observed that patients with abdominal aortic aneurysms (AAAs) seem to have an increased incidence of renal cysts on computed tomography (CT). In order to evaluate this possible association, a retrospective cohort study was conducted comparing the incidence of renal cysts on CT scan in 100 patients with AAA to 100 patients without AAA (matched by age and gender). Univariate analysis and multiple logistic regression were performed to evaluate the association of AAAs and other risk factors with the presence of renal cysts. Of patients with AAAs, 54% had renal cysts compared to only 30% in the control group (p = 0.0006, relative risk = 2.73). The AAA group had a higher incidence of chronic obstructive pulmonary disease (COPD, 14% vs. 1%), hypertension (76.6% vs. 46.5%), coronary artery disease (38.3% vs. 12%), and hypercholesterolemia (41.5% vs. 9.1%) compared to the non-AAA group. There was a significant linear correlation between renal cysts and COPD (p = 0.011), the presence of AAA (p = 0.0005), and age (p = 0.019), whereas hypercholesterolemia (p = 0.059) and diabetes (p = 0.063) approached significance. On multivariate analysis, there were three independent predictors of renal cysts: COPD (p = 0.051), age (p = 0.01), and AAA (p = 0.028). In conclusion, there is a significantly higher incidence of renal cysts in patients with AAA compared to patients without AAA. To our knowledge, this association has not previously been reported. Future studies are needed to determine whether this correlation is the result of a commonality in the pathogenesis of AAA and renal cysts.