Study of superior sagittal sinus and bridging vein with virtual reality technology

Objective To investigate the morphological characteristics of superior sagittal sinus (SSS) and bridging vein (BrV) with virtual reality (VR) technology and their clinical significances. Methods Forty-three patients with parasagittal meningioma (PSM group) and 21 patients with trigeminal neuralgia or hemifacial spasm who had no intracranial venous system diseases (normal group), admitted to our hospital from October 2011 to March 2013, were chosen. The morphological characteristics of SSS and parasagittal BrV of patients from the 2 groups were observed, which was finished in the VR workstation. The number and diameter differences of cortical veins between the 2 groups, and bilatelal side and the first, middle and third 1/3 of SSS of normal group were analyzed. Results Among the patients from the 2 groups, 4 having SSS extremity with morphological variation were observed firstly. The direction of BrV entering the SSS mainly was retrograde, which concentrated in the middle and third 1/3 of SSS. There were many directions of BrV entering the SSS in the first 1/3 of SSS, and the direction mostly was perpendicular. In normal group, there were no statistical differences of number and diameter in the bilatelal cortical veins (P>0.05); in the first, middle and third 1/3 of SSS, there was statistical difference of cortical veins number (P 0.05). The number and diameter of cortical veins of PSM group were under the normal group, with statistically significant difference (P<0.05). With the growth of PSM, violations of SSS and cortical venous gradually aggravated, affecting venous return, which resulted in increase number and complication of collateral veins. Conclusions There is certain variability of SSS and related BrV. The direction of BrV entering the SSS may be associated with intracranial venous system hemodynamic. It is clear and three-dimensional to observe SSS and cortical veins in the help of VR, and to analyze the venous circulation changes caused by PSM. Key words: Superior sagittal sinus; Meningioma; Cortical vein; Virtual reality