Ten unfixed human brains were examined under an operating microscope to evaluate the feasibility of reimplanting the parasagittal veins into the superior sagittal sinus. On average, there were 6.5 veins draining the surface of each hemisphere in the anterior frontal region, 3 veins draining each posterior frontal region, 4 veins draining each parietal region, and 1 vein draining each occipital region. The veins were most frequently 0.1 to 1.0 mm in diameter, but were as large as 3.0 mm in the anterior frontal and occipital regions, 3.5 mm in the parietal region, and 5.0 mm in the posterior frontal region. The mean vein length between the superior sagittal sinus and the first lateral attachment was 3.0 to 7.4 mm; individual veins were as long as 30.0 mm. The 20 hemispheres contained a total of 5 veins in the anterior frontal region, 7 veins in the posterior frontal region, and 8 veins in the parietal region that appeared to have an adequate diameter and length for microsurgical reimplantation into the superior sagittal sinus. The superior sagittal sinus had a mean width of 4.3 mm and depth of 3.6 mm in the midanterior frontal region and enlarged to a mean width of 9.9 mm and depth of 6.8 mm in the midoccipital region. In all sites, the sinus appeared to be structurally compatible with vein reimplantation. In 3 cases, veins 2.8 to 4.6 mm in diameter were reimplanted microsurgically into the sinus; in each case, the anastomosis was technically satisfactory and patient.(ABSTRACT TRUNCATED AT 250 WORDS)