Role of intraoperative microvascular Doppler in the microsurgical management of intracranial aneurysms.

Background. The outcome of surgical treatment of intracranial aneurysms may be influenced by incomplete exclusion of the aneurysm or stenosis of the parent vessels. The goal of this study was to evaluate the usefulness and reliability of intraoperative microvascular Doppler (IMD) in guiding optimal clip placement in aneurysm surgery. Methods. We conducted a retrospective analysis of 79 patients, with a total of 85 intracranial aneurysms, operated between January 2004 and April 2009, who were evaluated with IMD using a 20-MHz probe before and after clip application. IMD was used to examine the aneurysmal sac and adjacent vessels. Results. The findings of IMD helped in adjusting the clip placement. In 9 (10.6%) of the 85 aneurysms, IMD revealed a persistent blood flow through the aneurysmal sac after clip application and the clip was repositioned. IMD showed relevant stenosis of adjacent vessels induced by the clip positioning in 10 of 79 (12.7%) cases. In six cases (7.6%), a blood flow reduction in the artery feeding the aneurysm was evident after clipping; in the other four cases (5.1%), the clip produced a severe blood flow reduction in other adjacent vessels. In addition, in two of these cases, an initial stenosis induced by clip positioning that had escaped detection by visual inspection through the operating microscope was identified by IMD. There were no complications related to the use of IMD. Conclusions. IMD is a safe, feasible, and very reliable technique and should be used routinely in intracranial aneurysm surgery. (C) 2010 Wiley Periodicals, Inc. J Clin Ultrasound 39:27-31, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jcu.20751