Two-bone flap craniotomy for the transpetrosal–presigmoid approach to avoid a bony defect in the periauricular area after surgery on petroclival lesions: technical note

The authors describe a two-bone-flap craniotomy technique to avoid the bone defect caused by the transpetrosal–presigmoid approach. Briefly, this technique includes three steps. The first step is to elevate a temporoparietal bone flap located superiorly to the transverse and sigmoid sinuses. The second step is to dissect the transverse and sigmoid sinuses away from the bone by inserting a gelatin sponge. This maneuver provides hemostasis and protects the sinuses from injury. The third step is to cut a second bone flap including part of the temporal bone and the outer table of the mastoid bone with a high-speed drill system. After the operation, the two bone flaps are fixed in place with titanium osteosynthesis fixation material. This approach provides a simple, easy, and safe technique for the transpetrosal–presigmoid approach. The technique has been performed in 83 patients treated for petroclival neoplasms with excellent cosmetic results.