Background: The need for postoperative cerebral angiography to confirm clip placement is largely a matter of the individual surgeon's preference, but in an atmosphere of limited health care resources and rising costs this attitude may need to be changed.
Methods: A series of 312 intracerebral aneurysms harbored in 227 consecutive patients were clipped by a single surgeon (WF) and studied with postoperative selective angiography. Clues were sought to identify which (if any) aneurysms were prone to require postoperative recognition of incomplete or inaccurate clipping. We examined aneurysmal size, patient's sex, age, preoperative Hunt/Hess Grade, and Fisher CT grade, to determine their relationship to poor surgical clipping results (residual aneurysm or major vessel occlusion).
Results: There were 13 cases of residual aneurysm (4.2%) and one case of major vessel occlusion (0.3%). Deep midline aneurysms (posterior circulation, anterior communicating artery) and ophthalmic (paraophthalmic) artery regions formed a group of patients with an increased risk of imperfect clip placement (8.2%; 13/157) as compared to patients with aneurysms in other locations (0.6%; 1/155) (p < 0.05). In addition, incompletely obliterated aneurysms proved to have a high rehemorrhage rate in this series.
Conclusions: A retrospective analysis revealed that deep midline aneurysms are more prone to inadequate clipping, and therefore, as a bare minimum represent aneurysms requiring confirmatory postoperative evaluation. This contemporary series can be used as a basis to compare the results from intraoperative angiography.