Cavernous carotid aneurysms do not influence the occurrence of upstream ipsilateral aneurysm

Objective Cavernous carotid aneurysms (CCA) comprehend around 5% of all intracranial aneurysms. The main risk factors for an intracranial aneurysm seem not to influence the incidence of CCAs. The aim of this study was to investigate the association of CCAs and the presence of upstream aneurysms. Methods 1403 patients, admitted in Hospital das Clinicas de Sao Paulo, Brazil, from September 2009 to August 2018, enrolled this study. Diagnosis was performed with Digital Subtraction Angiography (DSA). Upstream aneurysm was defined as an intracranial aneurysm on anterior cerebral circulation, ipsilateral to the CCA (if present) or crossing the midline (e.g. anterior communicating artery). Results 177 individuals were diagnosed with CCA (12.6% of the population), totalizing 225 aneurysms (10% of the total number of aneurysms, 2253). No association was found between CCA and UA (p= .090, OR: 1.323, 95% CI: 0.957-1.828). Studying only patients with CCA, multivariable analysis showed smoking as the only factor associated with UA (p= .010, OR: 0.436, 95% CI: 0.232-0.821). Conclusions Cavernous carotid aneurysms were present in 12% of our population, mostly in female. They seem to be independent of the modifiable risk factors already associated with intracranial aneurysms. A higher frequency of mirror aneurysms was seen in this location. CCA did not influence the presence of ipsilateral and anterior circulation aneurysms.