Angiographic demonstration of postoperative cortical artery stenosis induced by Biemer temporary clips.

Five patients underwent cerebral revascularization operations during which Biemer clips were used to occlude temporarily a branch of the middle cerebral artery. Postoperative angiograms revealed stenoses at the sites where the clips were applied. Excessive clip closing forces may have caused significant endothelial injury, which then produced the stenoses. Clips that exert a minimal occlusive force would avoid this response and are recommended for temporary occlusion of cortical arteries.