Appropriate flow reduction for unilateral ruptured vertebral artery dissection by proximal clipping to prevent rebleeding and medullary infarction

Abstract Background Medullary infarction (MI) occasionally occurs after treatment of ruptured vertebral artery dissection (VAD). The aim of this study was to validate whether flow reduction for ruptured unilateral VAD by proximal clipping prevents rebleeding and MI in comparison with trapping. Methods Thirty-one patients who underwent direct surgery or endovascular procedures for unilateral ruptured VAD and postoperative MRI, including 9 treated with trapping and 22 treated with proximal clipping, were enrolled. For posterior inferior cerebellar artery (PICA)-involved type VAD, occipital artery to PICA (OA-PICA) anastomosis was added as needed to isolate the rupture point. The rate of rebleeding and the occurrence of MI on MRI were compared between the two groups. Results There was no rebleeding after treatment in all 31 patients. However, 5 patients had MI on postoperative MRI (16.1%, κ=0.903). In 5 of the 9 patients treated with trapping, MI was seen on MRI after treatment (55.6%). On the other hand, none of the 22 patients treated with proximal clipping developed MI (p Conclusion Appropriate flow reduction for ruptured unilateral VAD by proximal clipping is thought to be effective for preventing rebleeding and avoiding MI.