COLLATERAL BLOOD-SUPPLY TO THE CEREBRAL HEMISPHERES IN OCCLUSIVE LESIONS OF THE CAROTID ARTERIES

The collateral blood supply to the cerebral hemispheres was studied in 58 patients with occlusive diseases of the carotids on an ultrasonic apparatus based on an undamped wave with a beam frequency of 4 and 8 MHz by appraising the character of the blood flow in the supratrochlear artery in compression of the ipsilateral common carotid artery. The dissease was caused by atherosclerosis in 32 and by nonspecific aortoarteritis in 26 patients. Correlation of the character of the blood flow in the supratrochlear artery in compression of the ipsilar common carotid artery and the quantitative value of retrograde pressure in the internal carotid artery showed that the retrograde pressure in the internal carotid in patients with a safe residual antegrade flow of blood in the supratrochlear artery was significantly higher in compression of the ipsilar common carotid artery than in reduced and retrograde blood flow and was 70 +/- +/- 12,6 mm Hg, 33 +/- 12,4 mm Hg, and 34 +/- 10,7 mm Hg, respectively.