Etiopathogenesis, clinical presentation and management options of mirror aneurysms: A comparative analysis with non-mirror multiple aneurysms

Introduction: Mirror Aneurysms [MA] are a subset of multiple aneurysms which account for nearly 5% of all intracranial aneurysms and approximately 40% of all multiple aneurysms. The purpose of our study was to evaluate the etiopathogenesis, preferential location, clinical characteristics and outcome of mirror aneurysms in comparison with non-mirror multiple aneurysms. Methods: We retrospectively reviewed the clinical and radiological data of 358 patients with intracranial aneurysms who were treated at our institute between January 2014 and June 2018. The patients were further divided into non-mirror multiple and mirror aneurysm groups. There were 13 patients who had MA and 45 patients with non-mirror aneurysms [NMA]. Results: Multiple aneurysms were found in 16.2% of all patients [58 out of 358]. MA were observed in 3.6% [13 out of 358 patients]. There was a slight female predominance in the MA group [84.6% vs 73.3%]. The commonest location of MA in our series was MCA. There was no statistically significant difference in age, smoking, hypertension or postoperative outcome between the two groups. Conclusion: Management of mirror aneurysms should be determined individually based on the location, size, and morphology of the aneurysms, as well as the clinical manifestations of the patient. Therefore, emergent treatment of the ruptured aneurysm and staged management of the contra lateral unruptured twin can be considered as a rational treatment strategy to manage mirror aneurysms.