Intraoperative microvascular Doppler sonography in aneurysm surgery

Objective: The goal of this study was to evaluate the efficacy and reliability of intraoperative microvascular Doppler sonography (MDS) for the assessment of cerebral haemodynamics in aneurysm surgery. Methods: For 40 patients (21 men, 19 women, mean age 54.0 years, range 23-73 years) who underwent surgery for the treatment of 48 intracranial aneurysms, microvascular Doppler sonography with a 20-MHz microprobe was used before and after clip application, to confirm the complete obliteration of the aneurysm. Postoperative angiography was performed to assess the complete occlusion of the aneurysm and the patency of adjacent vessels. The findings of MDS were analysed and compared with the postoperative angiography. Results: A 1mm diameter microprobe was able to insonate all vessels of the circle of Willis and their major branches and perforating arteries were reliably insonated. The aneurysm clip was repositioned on the basis of the MDS findings in 12 out of 48 patients (25%). For 9 aneurysms (18.7%) MDS exposed a relevant stenosis of an adjacent vessel induced by clip positioning that had escaped detection by visual inspection. Clip repositioning resulted in complete occlusion of the aneurysms in 7 of 9 cases (14.5%). In two cases, additional wrapping became necessary as it was not possible to achieve complete clipping. The mean duration of MDS investigations was 5.3 minutes. There were no complications of intraoperative MDS probe use. Conclusion: Intraoperative MDS should. be used routinely in cerebral aneurysm surgery, especially for large, complicated and giant aneurysms. Intraoperative MDS is a feasible, safe, and very reliable technique in aneurysm surgery. This technique is a valuable tool, in many instances, in place of intraoperative angiography for the surgical treatment of aneurysms.