Abstract
Interhemispheric approach is a common route for aneurysmal surgery such as anterior communicating artery and distal anterior cerebral artery. During the procedure, preservation of the bridging vein is important. Until now, there has been no intraoperative monitoring system for the venous blood flow. We used microvascular Doppler sonography to monitor the venous blood flow velocity.
Eleven cases of anterior communicating artery aneurysm or distal anterior cerebral artery aneurysm. Venous blood flow velocity was measured at the following three different steps during the operation: before using the brain retractor, during the brain retraction with retractor, and after the operation. We used two different dissection techniques of the bridging vein according to the severity of adhesion between dura and bridging vein. In 6 cases, the bridging vein was dissected free for the whole length between the cortex and superior sagittal sinus (SSS group). In 5 cases, the vein was not dissected from the dura intentionally about 10 to 15 mm in length at its superior sagittal sinus side (dura group).
There is a strong tendency for venous blood flow velocity to decrease during the brain retraction in the SSS group. The blood flow velocity was well preserved in the dura group. Two out of 6 cases in the SSS group showed venous occlusion on postoperative angiography and they developed transient or permanent neurological deficit.
Our study revealed the importance of monitoring the venous blood flow velocity to minimize the postoperative complication due to venous circulation disturbance.
