Ultrasonographic Assistance during Surgery for Anterior Cerebral or Anterior Communicating Artery Aneurysm via the Interhemispheric Approach

Background: There have been two major problems in surgery for aneurysm via the interhemispheric approach. One is injury to bridging veins, which can cause serious venous infarction, and the other is disorientation when searching for the aneurysm using a microscope. We investigated the possibility of resolving these problems with ultrasonographic assistance during surgery. Method: Eleven patients with cerebral aneurysms underwent surgery via the interhemispheric approach. Eight patients had distal anterior cerebral artery aneurysms and three had anterior communicating artery aneurysms. Subarachnoid hemorrhage was seen in one patient in each aneurysm group. The average aneurysm size was 5.4mm, ranging from 2.9 to 6.8mm. Intraoperative ultrasonographic assistance involved two procedures: before opening the dura mater, the location of the bridging veins was determined using a micro-Doppler flow meter, and then the aneurysm was detected using B-mode ultrasonography with color Doppler imaging and the most appropriate route to the aneurysm was determined. Results: There were no operative complications in this series of aneurysm operations. There was no instance of bridging vein injury in any patient when the dura was opened. The most appropriate route to the aneurysm was revealed by B-mode ultrasonography with color Doppler imaging. Disorientation in searching for the aneurysm was not experienced, and all the aneurysms were successfully clipped. Conclusion: Intraoperative ultrasonographic assistance was a useful method for safer aneurysmal surgery via the interhemispheric approach.