Preservation of the superior petrosal sinus during the petrosal approach

Abstract

The petrosal approach is based on sectioning the superior petrosal sinus (SPS) and the tentorium. However, the venous anatomy in certain situations forbids this maneuver. The authors have derived a technique that enables the SPS to be spared during the performance of the petrosal approach. They describe the anatomical basis of this technique and report on 2 cases in which the technique was applied. Five alcohol-preserved cadaveric heads injected with colored silicone were used for bilateral dissection and demonstration of the technique. The described method was thoroughly investigated in these cadavers to assess its advantages, variabilities, and limitations. Subsequently, the technique was applied during the resection of petroclival tumors in 2 patients. The authors were able to demonstrate that the approach provides good access to the petroclival area through both the middle and posterior fossa in cadavers. By deriving a new technique of applying the combined petrosal approach without cutting the SPS, the senior author (O.A.M.) managed to achieve total resection of a dumbbell-shaped trigeminal schwannoma in a 19-year-old woman and of a petroclival meningioma in a 49-year-old man. This modification of the petrosal approach involving sparing of the SPS or cutting of the tentorium is an effective means for cases in which the venous anatomy mandates preservation of these structures.