Aneurysm rebleeding after treatments that leave the aneurysm sac patent

Three operations that leave the aneurysm sac patent have been used to treat ruptured intracranial aneurysms: carotid ligation, anterior cerebral artery ligation and aneurysm wrapping. The rates of early rebleeding (0-6 months) for these operations are respectively less than 10, 3.9 and 8.6%. The long-term risks of rebleeding are at least 1% per year for anterior cerebral or carotid artery ligation and 1.5% per year for wrapping. Eighty per cent of rebleeds are fatal. Most aneurysms are still seen to be patent if angiography is performed after these treatments. Should patients who have had these operations be offered aneurysm clipping?