Prevalence of Intracranial Aneurysms in Patients with Infrarenal Abdominal Aortic Aneurysms: A Multicenter Experience

Prior studies suggest high prevalence of intracranial aneurysms (IA) in patients with infrarenal abdominal aortic aneurysms (AAA). We reviewed our multicenter experience in clinical detection/treatment of IAs in AAA patients and estimated the risk of IA in patients with AAA relative to patients without AAA. We reviewed cases of vascular surgery infrarenal AAA repairs at three Mayo Clinic sites from January 1998 to December 2018. Concurrent controls were randomly matched in a 1:1 ratio by age, sex, smoking history, and head imaging characteristics. Conditional logistic regression was used to calculate odds ratios. We reviewed 2,300 infrarenal AAA repairs. Mean size of AAA at repair was 56.9 ± 11.4 mm; mean age at repair, 75.8 ± 8.0 years. 87.5% of the cases ( n  = 2014) were men. Head imaging was available in 421 patients. Thirty-seven patients were found to have 45 IAs for a prevalence of 8.8%. Mean size of IA was 4.6 ± 3.5 mm; mean age at IA detection, 72.0 ± 10.8 years. Thirty (81%) out of 37 patients were men. Six patients underwent treatment for IA: four for ruptured IAs and two for unruptured IAs. All were diagnosed before AAA repair. Treatment included five clippings and one coil-assisted stenting. Time from IA diagnosis to AAA repair was 16.4 ± 11.0 years. Two of these patients presented with ruptured AAA, one with successful repair and a second one that resulted in death. Odds of IA were higher for patients with AAA versus those without AAA (8.8% [37/421] vs. 3.1% [13/421]; OR 3.18; 95% confidence interval, 1.62-6.27, p  < 0.001). Co-prevalence of IA among patients with AAA was 8.8% and is more than three times the rate seen in patients without AAA. All IAs were diagnosed prior to AAA repair. Surveillance for AAA after IA treatment could have prevented two AAA ruptures and one death.