En bloc resection of the temporal bone by the lateral approach in carcinoma of the middle ear associated with skull base infiltration with reference to the resection of the petrous apex

En bloc resection of the temporal bone was performed by the lateral approac h on two patients with carcinoma of the middle ear, which was associated wi th destruction in the temporal bone and tumor infiltration of the cranial b ase. In one of the patients, the petrous apex was resected along with the t emporal bone. En bloc resection of the temporal bone with the petrous apex is believed to be difficult because the internal carotid artery (ICA), cavernous sinus, a nd the brainstem are adjacent to each other in the petrous apex. However, t he intra- and extracranial surgical procedures by this approach allow resec tion of the temporal bone ranging from the anterior part including the petr ous apex to the posterior part including the mastoid process, the dura of t he middle and posterior cranial fossae, and the sigmoid sinus, without expo sure of the tumor. Special attention should be paid to the procedural point s of surgery, such as, exposure of the petrous ICA, bleeding from the petro us sinus, and dural suturing in the vicinity of the apex. With regard to su rgical indication, it is important to determine whether tumor infiltration is confined to the temporal bone and the dura of the middle and posterior f ossa. If tumor infiltration into the petrous ICA, the dominant side of sigm oid sinus and/or the inferior cranial nerve is observed, then indication fo r surgery should be determined in a more critical manner.