Association between renal cysts and abdominal aortic aneurysm: A case-control study.

OBJECTIVE To investigate the positive association between the presence of simple renal cysts (SRCs) and abdominal aortic aneurysm (AAA). METHOD In a retrospective case-control study including subjects aged > 50 years, we evaluated the incidence of SRCs on computed tomography (CT) scan. We compared 91 consecutive patients with AAA referred from the Division of Vascular Surgery and 396 patients without AAA, randomly selected after being matched by age and gender from 3,186 consecutive patients who underwent abdominal CT. SRC was defined as a round or oval low-attenuation lesion with a thin wall and size > 4 mm on CT without obvious evidence of radiographic enhancement or septations. Patients were considered as having AAA if the size of aorta was greater than 3.0 cm. RESULTS Patients with AAA and without AAA were similar in terms of age (67.9± 8.41 vs. 68.5±9.13 years) (p=0.889) and gender (71.4 vs. 71.2% of male subjects, respectively) (p=0.999). There was no difference in the prevalence of SRC between case and controls. Among individuals with AAA, 38 (41.8%; [95CI 32.5-52.6]) had renal cysts compared to 148 (37.4%; [95CI 32.7-42.2]) in the control group (p=0.473), with a prevalence ratio (PR) of 1.16 (95CI 0.80-1.68). CONCLUSION We found no significant differences in the prevalence of SRCs among patients with AAA and controls. Our findings suggest that the presence of SRCs is not a risk factor or a marker for AAA.