1222. Stroke rate in patients with normal intraoperative angiogram after middle cerebral artery clipping.

Authors: Nazih Moufarrij, MD, FAANS (Wichita, KS)

Introduction: Middle cerebral artery (MCA) aneurysm clipping is still a frequently performed operation. Intraoperative angiography is sometimes used to check on the adequacy of clipping.This study analyses the occurrence of a stroke after the intraoperative angiogram is interpreted as normal. Methods: One hundred and four consecutive MCA aneurysm clipping were reviewed from a prospectively maintained data base and divided in 3 groups. In group 1, an intraoperative angiogram was not available. In group 2, it was available but not done. In group 3, it was done. The stroke rates due to clipping were calculated for each group. Results: The stroke rate was 4.5 times more when the intraoperative angiogram was normal compared to when it was available but not done. In group 3, 4 out of the 8 strokes are thought to be due to perforator injury, 2 out of the 8 due to vasospasm in a non ruptured aneurysm and 2 out of the 8 due to embolism. Conclusion: A normal intraoperative angiogram is no guarantee of a good outcome. Careful microsurgical strategy and technique with special attention to perforators, critical interpretation of the intraoperative angiogram, the use of sensory and motor evoked potentials as well as the use of indocyanine green or fluorescein angiography are expected to help decrease this complication.