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 1-mm 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.

Surgical treatment of distal anterior cerebral artery aneurysms with horizontal head position.

OBJECTIVE: In the surgery for a distal anterior cerebral aneurysm which is applied with a vertical head position, the dome of the aneurysm makes it difficult the expose the neck and the proximal artery. This study was performed to evaluate the applicability of the alternative contralateral interhemispheric approach with a horizontal head position for clipping these aneurysms. METHOD: The head of the patient was placed in the horizontal position such that the aneurysm side remained at the top and then tilted 45 degrees superiorly. On the contralateral side, the craniotomy, interhemispheric dissection and clipping were performed in 12 patients with 13 aneurysms. RESULTS: All aneurysms were clipped successfully. Problems in the standard supine position such as the obstruction of the access to the aneurysm neck and the proximal artery by the dome were not encountered. Vasospasm developed in 4 patients and akinetic mutism in 1 patient; postoperative convulsion due to an inadvertent cortical venous injury in one patient resolved with medical treatment. Hydrocephalus developed in 2 patients; one patient needed placement of a ventriculoperitoneal shunt while the other responded to occasional lumbar punctures. Mortality or permanent morbidity did not occur. CONCLUSION: The horizontal head position may be an alternative for circumventing difficulties posed by the location of distal anterior cerebral artery aneurysms.