Control of completeness and immediate detection of bleeding by a single laser-Doppler flow probe during intravascular middle cerebral artery occlusion in rats.

To detect the unintentional generation of subarachnoid hemorrhage (SAH) during thread occlusion of the middle cerebral artery (MCA) in rats, a single laser-Doppler flowmetry (LDF) probe was positioned over the ipsilateral cortex. Occlusion of the MCA resulted in an immediate drop of the LDF signal to 21.4+/-8.0% which was followed by a partial recovery to 31+/-11% in animals without SAH. In contrast, a sustained decrease to 7.4+/-5% (P<0.05 vs. non-SAH) occurred in animals with SAH. Thus, unintentional rupturing of the intracerebral carotid artery can easily and reliably be detected by single LDF monitoring immediately after MCA occlusion.