Optimal clip application and intraoperative angiography for intracranial aneurysms

BACKGROUND The actual incidence of residual aneurysm after clipping is unknown, The na tural history of residual aneurysm can be regrowth and hemorrhage. Intraope rative angiography offers a cost-effective, safe interdiction to the proble m of residual aneurysm and parent vessel stenosis, METHODS/RESULTS Forty consecutive patients harboring 54 aneurysms underwent 42 operative pr ocedures to clip 52 aneurysms, during which 220 intraoperative angiographic runs were performed. Ninety-three percent of the procedures were performed on patients with acute subarachnoid hemorrhage. There were 4 giant (>2.5 c m, 4/52 = 8%, all anterior circulation), 21 large (1.0-2.5 cm, 21/52 = 40%, 16/21 = 76% anterior circulation, 6/21 = 28% posterior circulation), and 2 7 small (<1.0 cm, 27/52-52%, 22/27 = 81% anterior circulation, 5/27 = 18% p osterior circulation) aneurysms. Intraoperative angiography led to clip adj ustment in 18/52 = 34% of aneurysms (4/18 = 22% for parent artery stenosis, 8/18 = 44% for residual aneurysm and 6/18 = 33% for both). Of the 18 adjus tments made, 16 = 88% were made on giant or large aneurysms and two were sm all (one was a complex anterior communicating and one was a vertebral junct ion aneurysm). Follow-up angiography was performed on 26/42 = 62% of operat ive cases. Postoperative angiography confirmed intraoperative angiography i n all cases. Two complications occurred during 220 angiographic runs: one e mbolic stroke and one incident of equipment failure. CONCLUSION A grading scale was applied to test the relationship between anatomical sit e and size as they relate to the necessity for clip adjustment for complete aneurysm obliteration and/or parent artery compromise. Significance was re lated to site (basilar bifurcation, anterior communicating, middle cerebral bifurcation, and ophthalmic) and size (>1.0 cm), both as independent and c odependent variables, An analysis of the cost-effectiveness of intraoperati ve angiography was demonstrated. (C) 1999 by Elsevier Science Inc.