A Superior Cerebellar Convexity Two-Part Craniotomy to Access the Paramedian Supra and Infratentorial Space: Technical Note

A craniotomy over the superior cerebellar convexity for approaches to this region typically involves a small infratentorial craniotomy and then drilling down of the bone to expose some portion of the transverse/sigmoid sinuses. The authors describe the anatomy of the region and the method for a two-part paramedian occipital and suboccipital craniotomy (supra and infratentorial) that may have time-saving, safety, and cosmetic advantages. For this technique, a supratentorial craniotomy is used to expose the transverse sinus from above, and subsequently, dissection across the sinus over the cerebellar convexity can be done under direct vision. The two bone pieces are joined on the inner table side while plates for fixation above the superior nuchal line can be counter-sunk to avoid post-operative pain from the prominence of screws. There is no need for cranioplasty materials since there is no burring down of bone for adequate exposure of the transverse sinus. The technique has been used by two senior surgeons over the years convincing them of the speed, safety, and utility of the technique. Here, the authors present a single example of the technique.