Transcript

Let's review the techniques for the modified orbitozygomatic craniotomy and also review the tenants for removal of interorbital tumors within the superlateral compartment of the orbit. This is a 62 year old female who presented with right-sided visual decline. And on imaging was noted to have a relatively well-defined lesion along the superior and lateral aspect of the orbit. Tumors located in this compartment are most amenable to resection via a craniotomy, to be able to completely resect the tumor and decompress the optic nerve via a client or ectomy. Here's the position of the head. As you can see, there is minimal turned to the head. Approximately 15 to 20 percent. The incision is a standard curvilinear arteriorenal incision all the way to the contralateral made pupilactic line. Importantly, a lumbar drain is used for dural SAC decompression early on. During on work. The skull flap is reflected in a separate layer than the temporalis muscle. The belly of the knife is used to mobilize the galea over the fat pad until their, the keyhole is palpated. The front talus branch is located within the superficial temporal fascia over the fat pad. It's a fascial technique is used to mobilize the fat pad while preserving the branches of the frontalis nerve. As you can see, I continue to mobilize the fat pad and protect the superficial temporal fascia. Obviously the nerves are not within the fat pad and the fat pad can be mobilized, laterally and interiorly until a resonal portion of the frontal process of zygoma is exposed. The muscle is mobilized after it's disconnected from its cuff and attachment to the superior temporal line. The muscle is mobilized inferiorly and posteriorly. Unlike it traditional pterional craniotomy where the muscle is reflected enteriorly and inferiorly. The area of the pterional is generously exposed. The periorbital is dissected from the inner surface of the orbit to protect the orbital contents during the craniotomy Frontal zygomatic suture is identified. This is an important technical mucous that I would like to emphasize here that the initial keyhole is placed about a few millimeters above and about seven millimeters posterior to the location of the frontal psychosomatic suture. The angle of the drilling is about 45 degrees against the surface of the skull. Perpendicular drilling would lead me to expose primarily the frontal dura without reaching the periorbita and exposing the orbita roof. Again, it's really important for creating the real key hole to avoid a perpendicular drilling. As you can see here, use a 45 degree to trilling. As demonstrated here, you can see the roof of the orbit, the frontal dura and the periorbita. All exposed within the keyhole. This is the real McCarty keyhole lumbar drain alouds generous the decompression of the dural sac periorbital contents are protected. You can see the presence of the tumor led to interorbital hypertension and herniation of orbital fat. The roof of the orbit is isolated. Performance of it. Good keyhole is essential for conduction and performance of the one piece modified orbital psychosomatic craniotomy. The dura is mobilized away from the inner surface of the skull. After another bare hole is placed along the posterior aspect of the pony exposure, just inferior to the superior temporal line. The initial bony cut or craniotomy starts along the posture per hole and goes all the way to the level of the orbital roof and preferably avoids their frontal sinus. As the progress of the footplate is prevented. Since the footplate is touching the orbit or roof. It trill is backed away and removed. The second craniotomy is obviously around the temporal area until this spinal wink avoids further progress of the foot plates. The b1 without a footplate is used to cut the orbital rim. Obviously avoiding their super orbital nerve. Additional bone cuts are performed over the frontal process of zygoma extended reaching the previous bone cut over the area of this spinal wink. Secondly, the area of the pterional is also thinned out over the spinal wink until they keyhole is reached. Two cottons and patties are used to mobilize the dura and the interorbital contents away from the orbital roof. While a small osteotome is used to fracture the roof of the orbit. Toward the cut at the level of the orbital rim. Next, the bone flap is gently elevated. You can see the orbit and the dura well decompressed by the lumbar drain. You can see the superior orbital fissure, the location of the tumor. The tumor had eroded through the poster aspect of the orbit. Here's the area of the client had process that was unnecessary to remove in this case. Since the tumor ends just about at the location of my arrow, here is the superior orbital fissure. Here's the tumor. You can see the entry of the optic nerve into its foramen, just here. Just need to the climate process. Here you can see the entry of the optic nerve into its foramen. The frontal sinus was not entered. Tack up stitches are placed along the frontal and temporal areas to prevent postoperative fluid collections. Here is the generous modified orbiter sagomatic craniotomy that is quite effective to expose parasellar lesions. Extending superiorly high riding suprasellar tumors are excellent candidates, including those within the interpedicular sisterns. The periorbital over the tumor is incised. The tumor is relatively gelatinous. Microdissection exposes the entire roof of the tumor. Next, the tumor is mobilized. The intact periorbita is preserved. Here's the tumor mobilized out of its cavity. That unaffected area of the periorbita is protected. This tumor was confirmed to be sure anoma. Stared their section cavity, which is very clean unaffected by the tumor. This is the final product after resection. The bone flap is replaced. Try to avoid the mini plate here, if possible. Obviously the orbital rim has to be lined up well with the area of the craniotomy to avoid any step offs that can lead to post operative deformity. Thank you.

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