De Novo Aneurysms in Long-Term Follow-Up Computed Tomographic Angiography of Patients with Clipped Intracranial Aneurysms

ObjectiveThis study was undertaken to evaluate de novo aneurysm formation in the long-term follow-up of patients with clipped aneurysms.MethodsOf 459 patients who underwent clipping of ruptured cerebral aneurysms at our institution between 1997 and 2008, 119 patients were available in good condition and agreed to undergo 64-detector row computed tomographic (CT) angiography. In addition, eight patients underwent CT angiography for new subarachnoid hemorrhage.ResultsThe mean ± standard deviation interval from surgery was 7.2 ± 2.3 years for CT angiography controlled patients. De novo aneurysms were detected in 5 of 119 (4.5%) patients and 4 of 8 patients with new subarachnoid hemorrhage. A history of multiple aneurysms was associated with de novo aneurysm formation (P < 0.001).ConclusionThe risk of de novo aneurysm formation in patients with clipped aneurysms is significant in long-term follow-up. CT angiography can be used as a noninvasive method for detection of de novo aneurysms in these patients.