Microsurgical anatomy of the superior sagittal sinus and draining veins.
The superior sagittal sinus and the draining cerebral veins are often encountered during the surgery for parasagittal and falx meningiomas and during the interhemisperic transcallosal approaches. A knowledge about the variations from the normally described anatomy helps in anticipating and avoiding problems related to these structures during surgery. The normal variations in the disposition of the superior sagittal sinus and the number and direction of the draining veins in the Indian population have been studied. This is an anatomical study in the fresh cadavers. Sixty fresh cadavers were examined in the autopsy theatre of the Forensic Medicine Department of the Hospital between March 2011 and February 2013. Epi-Info, MS-Excel, and the Statistical Package for the Social Sciences (SPSS) were used for data analysis. The position of the superior sagittal sinus was variable and was up to within 1cm on either side of the sagittal suture. The origin of the superior sagittal sinus varied from the level of foramen caecum to a little posterior from the foramen caecum. The total length of the superior sagittal sagitttal sinus varied from 321 mm to 357 mm (average length 338.77mm); vertical compartments of the sinus were found in three-fourth of the cases studied. Tributaries were found in the herringbone pattern and varied from 13 to 19 on the right and 14 to 19 on the left. The Rolandic vein was the largest draining vein in most of the cases. The superior sagittal sinus drained predominantly to the right transverse sinus in three-fourth of the cases studied. The position of the torcula was variable; often towards the right side and at a higher level. The central sulcus was 49.93 mm posterior to the coronal suture and 130.78 mm anterior to the lambdoid suture. This is the first study of its kind in Indian population studying the anatomical variations in the anatomy of the superior sagittal sinus that may have a significant bearing on the neurosurgical approaches adopted.