Applying critical pressure to middle cerebral artery in dogs.

The purpose of our model was to provide maximum pressure level of the middle cerebral artery (MCA) without causing any histological variation like focal cerebral ischaemia. In this experimental study 9 dogs were used. A modified Spetzler occluder was applied to the MCA of the dogs to determine regional cerebral blood flow (rCBF) and somatosensory evoked potentials (SSEP). Seven animals underwent the surgical procedure with measurements of rCBF after arterial microdissection and then after applying 80% blood pressure (BP) to the MCA for 15 minutes. In rCBF a 29% average reduction was observed. The average value of rCBF at the end of 15 minutes was 63.5 +/- 6.52 ml/100g min. Simultaneous somatosensory evoked potential recordings were also obtained. When rCBF was reduced 29%, 80% BP applying to MCA did not cause complications.