Clinical microanatomy of the bridging veins draining into the superior saggital sinus in the anterior transcallosal approach

Abstract

Objective To observe the microanatomy of the bridging veins emptying into the superior sagittal sinus (SSS) for preservation of the bridging veins in surgeries through the anterior transcallosal approach. Methods Blue latex was injected into the SSS and internal jugular veins in 20 cadaver heads (40 sides), in which the bridging veins of the frontal and central were dissociated and their positions relative to the body surface were determined. Such indexes of the lateral veins in each as the caliber, the number of bridging veins, and convergence angle were determined. The opposite hemisphere was manipulated in an identical manner to measure the indexes of the sagittal sinus. Results in an area posterior to the frontal region of the SSS, a safe zone was identified where no bridging veins drained into the SSS, covering the area 32.6 nun anterior and 7.5 mm posterior to the coronal suture. After complete dissociation of the bridging veins near the longitudinal fissure in the safe zone, the fissure allowed an opening width of 4.48～10.86 mm. Conclusion Thorough knowledge of the venous anatomy can help avoid the bridging veins in the anterior transcallosal approach. Total dissociation of the sticking segment and arachnoid segment of the bridging veins can broaden the opening width of the longitudinal fissure without increasing the tension of the bridging veins to better preserve the bridging veins during surgery. Key words: Superior sagittal sinus; Bridging veins; Microdissection