Y, temporal craniotomy is needed (Figure 6A). If the tumor does not invade the temporal lobe of the cerebrum, the superior reduce is per formed from the middle cranial base. The cutting line extends in the epitympanic cavity and tympanic ostium of the eustachian tube towards the glenoid fossa and connects the inferior bone cutting line (Figure 7B,C). En bloc resection with dura matter remains debatable, and Nakagawa et al. have stated that posterior cranial dural invasion is a contraindication for surgery, but surgery is deemed for cases with dural invasion towards the middle cranial fossa [20]. 4.four.3. Posterior Extension Tumors within the EAC can generally destroy the posterior wall on the canal in to the mastoid cavity. This extension from the tumor very easily reaches the vertical segment on the facial nerve. There’s insufficient space involving the tumor and also the vertical segment from the facial nerve. To attain the adverse margin resection, facial nerve resection must be regarded (Figure 7B). In such a case, retrofacial mastoidectomy should be performed in the tym panic cavity. If mastoid air cell opacification is identified broadly as a result of the in depth in vasion, eLTBR isn’t a suitable procedure from an oncological viewpoint. 4.4.4. Anterior Extension Tumors with anterior extension sometimes need en bloc resection with the gle noid fossa/TMJ (Figure five). When the tumor extends anteriorly but does not invade the condylar procedure or bone in the glenoid fossa, the surgeon can separately eliminate the con dylar approach and proceed with tumor removal, confirming the tumor margin. If the bone of your condylar course of action has been invaded by the tumor but the glenoid fossa has not, the neck from the condyle really should be cut, the condyle translocated laterally, and also the periosteum separated in the bone with the glenoid fossa. This can expose the bony surface in the vag inal process rendering en bloc resection with TMJ feasible. In such scenarios, the petrous carotid is usually exposed by 5′-?Uridylic acid Description drilling the bone through the glenoid fossa. In case of invasion towards the bone of the glenoid fossa or TMJ, which doesn’t allow the exposure in the vaginal approach preventing the exposure in the tumor, the surgical procedure is fully dif ferent due to the fact temporal craniotomy is required. The superior reduce is performed in the epitympanic cavity and tympanic ostium of the eustachian tube for the greater wing of theCancers 2021, 13,26 ofsphenoid bone, even though passing laterally towards the foramen spinosum and anterior for the gle noid fossa and connecting the anterior and inferior bone cutting line (Figure 7B,C) [30]. This process enables complete en bloc resection with all the TMJ/glenoid fossa. 4.five. Conventional STBR Traditional STBR calls for temporooccipital craniotomy (Figure 7A) and removal from the condyle right after cutting the ramus from the mandible or neck with the approach. Dura with the middle fossa and posterior fossa in the mastoid and petrous bone are separated from the temporal bone. The petrous carotid can be exposed by way of the glenoid fossa. The internal auditory meatus could be cut either from the middle cranial fossa or posterior cra nial fossa. Finally, a medial reduce from the pyramidal bone might be accomplished promptly lateral towards the vertical segment of the petrous carotid (Figure 7B,C). Exposure on the vertical to horizontal segments from the petrous carotid in the gle noid fossa has been reported with clear il.