Background: Radiation-induced intracranial aneurysm (RIICA) is a rare complication. From the literature, 74.1% of the reported RIICA ruptured with aneurysmal subarachnoid hemorrhage (SAH), and the mortality rate was 42.3%. Here, we report a case of repeated SAH due to a RIICA after surgical clipping.
Case description: A 42-year-old woman presented with SAH. She had undergone radiotherapy for suprasellar germinoma 27 years previously. Digital subtraction angiography (DSA) showed an aneurysm at the anterior wall of the non-branching site of the left internal carotid artery and multiple luminal narrowing. The aneurysm was located within the radiation field, and was not detected by previous DSA. Surgical clipping was performed, but bleeding repeated after 3 months. We performed a second neck clipping and confirmed that the clip had slipped from the neck of the aneurysm. Thirty-nine days after the second operation, DSA revealed an enlargement of residual neck of the aneurysm. Therefore, we performed an endovascular stent-assisted coil embolization of the aneurysm. At the end of the endovascular coiling, the small residual neck of the aneurysm was still observed. The follow-up DSA obtained three weeks after the coil embolization demonstrated enlargement of the residual neck. At 6 months after the first coil embolization, we performed an additional coil embolization which achieved complete obliteration of the aneurysm. Her cranial nerves were intact, and motor and sensory examinations revealed no deficits. Close followup by imaging is in progress.
Conclusion: A careful annually follow up, with not only MR imaging but also MR angiography as well, is important for the patients who had a full response to radiation therapy for germinoma in childhood. Special attention must be paid in the treatment of RIICA patients, because of fragility of arterial wall adjacent to the RIICA and the radiation-induced severe atherosclerotic change.
Hiroki Kuroda, Mitsuru Dan, Daisuke Yamamoto, Hiroyuki Koizumi, Ryushi Kondo and Toshihiro