**5.2 Case 2**

A 50-year-old male underwent an MRI at a medical health examination. The MRI detected a mass effect in the infratemporal fossa incidentally. The tumor was located in the cavernous sinus and the imaging was evocative of trigeminal schwannoma. The tumor resection was undertaken through a transcranial transcavernous sinus, extradural anterior infratemporal fossa approach. Frontotemporal approach was performed and elevated the frontal and temporal dura from the sphenoid bone. After identifying the superior orbital fissure and elevating the dura propria, the FR and FO were identified and exposed the V1, V2, V3 and the gasserian ganglion. However, the trigeminal nerve fibers lie on the surface of the tumor. In order not to damage the trigeminal nerve fibers, the maxillary strut was drilled and gained the working space to the tumor from the anterior aspect of the tumor. The pterygoid process, between V2 and V3, was thin and was easily drilled to allow wide exposure of the sphenoid sinus. The tumor extension into the SphS was better appreciated under endoscopic visualization. A more extensive resection was accomplished with this approach, although it remained subtotal. The posterior part tumor was removed through the petrous corridor. The pathology was concordant with a schwannoma, from the trigeminal nerve. After tumor resection, the window of

#### **Figure 7.**

*Pre and post-operation MR images of the cavernous sinus meningioma and intraoperative images of the cavernous meningioma surgery. A, B. preoperative MR image show enhanced mass effect originates from the cavernous sinus extends into the sphenoid sinus. C, D. postoperative MR image shows the yellow arrow showing the removal of the tumor in the sphenoid sinus. E. Sphenoid sinus was opened between the V1 and V2. F. Incision was made between the Muller's muscle and V2. G. the zygomatic temporal nerve was identified in the distal of the V2 and the window of the V1-V2 corridor was enlarged. H. Endoscopic view shows a tumor in the sphenoid sinus and removed with suction. I. Two instruments are inserted through the V1-V2 triangle. IOF; inferior orbital fissure, PPF; pterygopalatine fossa, MM; Muller's muscle, SOF; superior orbital fissure, V1; ophthalmic nerve, V2; maxillary nerve.*

*Surgical Approach to the Cavernous Sinus and Middle Cranial, Pterygoid Fossa DOI: http://dx.doi.org/10.5772/intechopen.104956*

#### **Figure 8.**

*A: T1 gadolinium enhanced MRI shows a high intensity lesion located in the pterygoid fossa, with an extension up to the sphenoid sinus. B: CT scan shows a mass lesion faces on the sphenoid sinus. C: Post-operative MRI T1 gadolinium image shows the tumor was removed. D; intraoperative microscopic view of the anterior infratemporal fossa view after resection of the tumor. The FLT and AMT were opened, and sphenoid sinus mucosa was seen inside of the sphenoid sinus, between V1-V2 and V2-V3. E; intraoperative endoscopic view below the V2 and the Gasserian ganglion. The tumor can be seen under endoscopic visualization. V1; ophthalmic nerve, V2; maxillary nerve, V3; mandibular nerve, Tu; tumor, SphS; sphenoid sinus, rt.VN; right vidian nerve.*

the SphS was covered with a vascularized fascial flap harvested temporal muscle, supplemented by fibrin glue. The postoperative outcome was with slight facial sensation. (**Figure 8A, B, C, D, E**).
