Fig.17. Stages of a bifrontal approach, ensuring preservation of the frontal pole veins.
A - dura mater is dissected on the left and right, beginning with anterior segments of the upper sagittal sinus;
B - a large vein of the left frontal pole;
C - the cock's comb is exposed. Anterior segments of the sinus are cut off from the cecal foramen area;
D - frontal poles, draining veins and the upper longitudinal sinus are lifted in the upward-backward direction.