The relationship between parasagittal and falcine meningiomas and the superficial cortical veins: a virtual reality study.

OBJECTIVES

Surgery for parasagittal and falcine meningiomas requires meticulous preservation of the cortical veins that surround the tumour; thus, knowledge of the relevant venous anatomy would be extremely helpful during surgery.

METHODS

This study utilises virtual reality technology to determine the number, size and disposition of the veins in relation to the tumour in 8 patients with parasagittal and falcine meningiomas. The same data were also collected from the scans of 8 normal subjects and compared with the data from the meningioma patients.

RESULTS

Our results show that the average number of veins is comparable in the tumour and control groups, and that the number of veins on either side does not differ significantly for both groups. On measurement, the size of the veins is approximately the same on either side of the superior sagittal sinus for both the control and the tumour groups. It was also observed that regardless of size, most of the parasagittal and falcine meningiomas demonstrated no significant anatomical distortion effects on the adjacent venous structures, with the exception of one parasagittal meningioma with invasion of the superior sagittal sinus and concomitant engulfment of the draining veins.

CONCLUSION

Data from a larger population would have to be collected in order to determine the effect of the growth of these tumours on the surrounding venous anatomy. With virtual reality technology, the parasagittal veins are clearly discerned, and knowing their location and relationship to the tumour would contribute towards safe and effective surgery.