Physiological function after middle cerebral artery occlusion in rabbits with neovascularization of the brain by transposed omentum.

The effect of brain neovascularization by omental transposition on somatosensory evoked potentials and on regional cerebral blood flow (rCBF) measured by hydrogen clearance was evaluated in rabbits exposed to experimental ischemia after occlusion of the middle cerebral artery (MCA). After MCA occlusion, the animals with brains neovascularized by transposed omentum showed a mild drop of rCBF accompanied by normal patterns of somatosensory evoked potentials elicited by sciatic stimulation. In the control animals, the evoked cortical electrical activity drastically decreased in amplitude immediately after arterial occlusion and fell to zero one-half hour later. The decay of bioelectrical activity in these rabbits was associated inevitably with a major drop in the rCBF. Morphological examination, as well as the functional data, indicate that omental transposition in animals exposed to experimental ischemia minimizes the occurrence of cerebral infarction because the neovascularization is capable of maintaining the local blood flow for at least 1 hour; therefore, the cortical electrical activity is preserved totally. In the light of these results, the authors suggest that this surgical technique can also be utilized in human beings who are affected by transient ischemic attacks to prevent more serious consequences.