[Kissing Mirror Aneurysms of the Anterior Communicating Artery. A Case Report].

Kissing aneurysms are defined as two adjacent aneurysms arising from identical or different arteries with separate origins and partially adherent walls. Mirror aneurysms are defined as intracranial aneurysms located in similar positions bilaterally on the parent arteries. Both kissing and mirror aneurysms at the anterior communicating artery(AcomA)are rare. We report a case of subarachnoid hemorrhage(SAH)due to ruptured kissing mirror aneurysms of the AcomA. An 80-year-old woman was admitted to our hospital with a sudden headache and vomiting. CT revealed diffuse SAH. Digital subtraction arteriography(DSA)revealed an aneurysm at the right A1-A2 junction of the AcomA. Hence, coil embolization was performed. On day 14 following embolization, rebleeding occurred. DSA revealed complete occlusion of the aneurysm at the right A1-A2 junction. However, left carotid angiography revealed an aneurysm at the left A1-A2 junction. We did not understand the anatomical construction of the aneurysms;therefore, we selected microsurgical treatment to clip the AcomA aneurysm using an interhemispheric approach. The left A1-A2 junctional aneurysm was anterior to the right A1-A2 junctional aneurysm, which was coil embolized. We detected the left A1-A2 junctional aneurysm as a ruptured aneurysm. The two aneurysms were adhered to each other. After dissection to expose the aneurysmal neck, the left A1-A2 junctional aneurysm was clipped. Kissing mirror aneurysms are difficult to diagnose before treatment. Knowledge and suspicion of the occurrence of kissing mirror aneurysms in the AcomA are important.