Appliance of microvascular Doppler ultrasonography in internal carotid artery aneurysms surgery

Abstract

Objective The goal of this study was to evaluate the efficacy and reliability of intraoperative microvascular Doppler (MVD) for the assessment of cerebral hemodynamics during internal carotid artery aneurysm surgery. Methods MVD with a 20-MHz probe (1.5 mm diameter) was used before and after clip application on 32 patients who underwent surgery for the treatment of 36 intracranial aneurysms. Assessment of the patency of the parent vessels and all branching arteries was performed. The findings of MVD were analyzed and compared with the postoperative angiography. Results The vascular murmur could be easily detected by MVD in all aneurysms. The aneurysm clip was repositioned on the basis of the MVD findings in 11 out of 32 patients. Among 8 aneurysms MVD exposed to a relevant stenosis of parent artery, one case of supraclinoid segment giant aneurysm was resected and internal carotid artery was reshaped. Blood flow signal of distal internal carotid artery did not appear and clip repositioning resulted in complete obliteration of the aneurysms in 2 of 32 cases. After the aneurysm clipping, MVD demonstrated an absent flow signal in the domes of aneurysms indicating these domes were obliterated completely, which disclosed clearly the patterns, direction, and velocity of blood flow of the parent artery and their branches suggesting patency of these arteries. Postoperative angiography confirmed the complete occlusion of the aneurysm and the patency of adjacent vessels. The incidence of stenosis, occlusion of parent artery and aneurysm failing to be occluded were closely correlated with the size of aneurysm and the parent artery with atherosclerotic plaque. Conclusion It is recommended that using MVD routinely in cerebral aneurysm surgery, especially in large, complicated and giant aneurysms with wide neck or without neck. Key words: Internal carotid artery aneurysm; Microvascular Doppler; Microprobe; Hemodynamic