CORRELATION BETWEEN VENOUS STUMP PRESSURE AND BRAIN-DAMAGE AFTER CORTICAL VEIN OCCLUSION - AN EXPERIMENTAL-STUDY

A canine model of cortical vein occlusion was used to evaluate whether data obtained from monitoring venous stump pressure could help predic t cerebral infarction after venous obstruction. Following bilateral pa rasagittal craniotomy, the cortical vein in each hemisphere was tempor arily occluded and the increase in pressure was directly measured. Per manent venous obstruction was subsequently produced, and parenchymal b rain damage 24 hours later was classified as: Stage 0, no parenchymal damage; Stage I, mild edema; Stage II, moderate parenchymal edema and/ or ischemic changes in neurons; and Stage III, moderate-to-severe hemo rrhage. The histological stages correlated closely with the rise in ve nous pressure: mean pressure increases (+/- standard deviation) were 5 .5 +/- 2.9 mm Hg in hemispheres graded as Stage 0 (12 hemispheres), 7. 7 +/- 3.2 mm Hg in those graded as Stage I (five), 11.2 +/- 4.1 mm Hg in those classed as Stage II (five), and 16.4 +/- 5 in those categoriz ed as Stage III (seven). There were significant differences between St ages 0 and II (p < 0.01) and between Stages 0 and III (p < 0.001). Dis ruption of the blood-brain barrier as indicated by extravasation of Ev ans blue dye correlated well with the pressure increment. These result s may indicate the threshold for injury after cortical venous occlusio n. Venous stump pressure measurements obtained during a test occlusion may be a useful adjunct in predicting brain damage and may be helpful for intraoperative vessel selection for venous resection.