Intracranial Aneurysm Following Cranial Radiation Therapy
This 69-year-old woman was found to have a large mass destroying her sphenoid sinus when she lost vision in her right eye eight years prior to current presentation (). During the surgical removal of tumor, there appeared to be a chance of injuring the internal carotid artery (ICA). We therefore performed preoperative catheter angiography and balloon test occlusion. The anterior communicating artery was widely patent on the balloon test occlusion, and no vascular abnormalities, including aneurysm, were identified by the catheter angiography (). She underwent gross-total resection of the tumor at that time without any adverse event, and a pathological examination confirmed the diagnosis of chondrosarcoma. She subsequently underwent cranial radiation therapy (total dose of 59.4 Gy) as adjuvant treatment. She was clinically monitored throughout the next eight years with serial magnetic resonance imaging (MRI). During this time, she demonstrated no new neurological deficit except slight cognitive decline, and none of the MRIs showed any sign of residual or recurrent tumor ().\nThe patient presented to the emergency room due to severe headache and a slightly drowsy mentality, and computed tomography (CT) revealed intracerebral hemorrhage and subarachnoid hemorrhage (). The patient underwent catheter angiography, which revealed an aneurysm of the anterior communicating artery and luminal narrowing and irregularity in the petrous and lacerum segments of the right ICA ().\nWe suspected that the anterior communicating artery aneurysm had ruptured and attempted endovascular treatment with coil embolization. However, the tortuosity of the bilateral A1 segments of the anterior cerebral arteries (ACAs) and the broad neck of the aneurysm made the endovascular treatment difficult. We stopped the endovascular treatment and surgically clipped the aneurysm. During the microsurgery, the wall of the aneurysm was very rubbery, and the surgical clip slipped from the neck of the aneurysm. After several surgical clipping attempts, the neck of the aneurysm was clipped, and a booster clip was used to reinforce the primary clip. The patient's immediate postoperative neurological state was the same as baseline. CT angiography performed ten days after surgery revealed the small, residual neck of the aneurysm, but the patient's state was stationary (). At 14 days after surgery, the patient's mental state worsened, and a CT revealed rebleeding from the aneurysm; catheter angiography demonstrated that the clips had slipped from the aneurysm (). We performed emergency surgery using a contra-lateral craniotomy and confirmed that the clips had slipped from the aneurysm; new clips were applied around the aneurysm neck. The patient's neurological state immediately after the 2nd operation was deeply drowsy. However, three days after the 2nd operation, the patient became semicomatose, and CT and catheter angiography revealed rebleeding and the slip of the clips, respectively. After the repeated failure of surgical clipping, we performed endovascular trapping from the right distal A1 to the aneurysm (). After the procedure, the final catheter angiogram showed complete obliteration of the aneurysm and intact flow of the bilateral A2s ().\nAfter the endovascular treatment, her neurological state was semi-comatose, and we continued conservative management. One month after the endovascular treatment, there was massive bleeding from her nasal cavity, and catheter angiography showed a rupture of the lacerum segment of the right ICA, suggesting carotid blow out syndrome (). We performed endovascular coil embolization of the ruptured site in the lacerum segment of the right ICA as a life-saving procedure (). The patient did not recover from the semi-comatose state and was discharged home in a bed-ridden state.