Is exposure of the superior sagittal sinus necessary in the interhemispheric approach?

Objective: Techniques for anterior interhemisperic craniotomy vary in respect to the degree of exposure of the superior sagittal sinus (SSS). The aim of this anatomic study is to quantify the increase in the angle of view gained by wide exposure and retraction of the SSS.

Methods: The anterior interhemispheric approach was performed in 10 cadaveric specimens with and without complete exposure and retraction of the SSS. Prespecified anatomic targets within the depth of the surgical field were used to calculate the angle of view.

Results: Complete exposure of the SSS in the anterior interhemispheric approach, increased the angle of view from 20.6 +/- 3 to 26.8 degrees, using the A4-A5 junction as a deep anatomic target (P = 0.008). When the free edge of the falx was considered as a deep anatomic target, complete exposure of the SSS increased the working angle from 34 +/- 3.14 to 42.1 +/- 4 (P = 0.0004).

Conclusion: In this study, we demonstrate a significant increase in the angle of view after complete exposure of the SSS, targeting either deep (anterior cerebral artery) or more shallow structures (free falx edge).