Role of intraoperative angiography in the surgical treatment of cerebral aneurysms.

UNLABELLED The benefit of using intraoperative angiography (IA) during aneurysm surgery is still uncertain. OBJECT In this prospective study, the authors evaluate the radiographically demonstrated success of surgical treatment in 151 consecutive patients harboring 173 aneurysms who selectively underwent IA examination. The authors also assess the frequency with which IA led to repositioning of the aneurysm clip. METHODS Intraoperative angiography was used selectively in this series, based on the surgeon's concern about the potential for residual aneurysm, distal branch occlusion, or parent vessel stenosis. Specific variables were analyzed to determine their impact on the incidence of clip repositioning and the accuracy of IA was evaluated by direct comparison with postoperative angiography (PA) in 90% of the cases in which IA was used. CONCLUSIONS The selective use of IA led to successful treatment as shown by PA, with a low incidence of unexpected residual aneurysm (3.2%), distal branch occlusion (1.9%), and parent vessel stenosis (0%). Intraoperative angiography led to immediate repositioning of the aneurysm clip in 27% of the cases. Anterior cerebral artery aneurysms required clip repositioning less often and superior hypophyseal artery aneurysms required repositioning more often than aneurysms in other locations. Large and giant aneurysms required clip repositioning more often than small aneurysms; however, they were also more likely to display false success on IA as determined by PA. Aneurysms arising along the internal carotid artery were more likely to display successful clipping on IA, as determined by PA, than were aneurysms in other locations. The results of this series support the selective use of IA in the treatment of complex aneurysms, particularly large and giant aneurysms as well as superior hypophyseal artery aneurysms. As measured by PA, IA will improve the outcome of these patients.