Mount Sinai neurotologists work closely with their neurosurgical colleagues to treat patients with acoustic neuroma, also known as vestibular schwannoma, which are benign tumors on the hearing and balance nerves. Acoustic neuromas may cause hearing loss, vertigo/dizziness/imbalance, tinnitus/ringing in the ear, or other problems if sufficiently large. They are typically slow growing, but a small percentage will grow quickly. Generally, treatment may consist of surgery, radiation, or observation, and depends on the patient’s age, tumor size, symptoms, hearing status, and preference. Patients with large tumors and brainstem compression typically undergo surgery. Tumor size does not always correlate with hearing loss. In some cases, particularly smaller tumors, we are able to preserve a patient’s hearing. In other cases, we may place a cochlear implant for those patients with severe or profound hearing loss.https://www.mountsinai.org/locations/skull-base-surgery-center/conditions/acoustic-neuroma
Featured Faculty
George Wanna, MD, FACS Maura K. Cosetti, MD Enrique R. Perez, MD, MBA Zachary G. Schwam, MD
The Mount Sinai skull base surgery video series presents trans labyrinthine approach for a vestibular schwannoma. This procedure is commonly performed as a team approach between our neurotologist and skull based neurosurgeons. This video was edited by Zachary Swan. Here we have a patient with a rather small yet very symptomatic vestibular Schwannoma who insisted on resection because of his profound hearing loss. We opted for a trans labyrinthine approach. This is a right mastoid with the soft tissue work already performed. As in other videos. The outline of the craniotomy is shown here with some anatomy for orientation. We start drilling with a large cutting burn, outlining the craniotomy. We then drill within the lines drilling parallel to the middle foid dura, sigmoid sinus and ear canal. We exenterate the mastoid air cells only some of which are shown here. We start to see the shadow of the sigmoid sinus through bone with some more drilling. We also see the shadow of the middle fossa dura. The lateral semi circular canal is our initial depth marker. We then accelerate the root of the zygoma to better see the incus and mallus as they articulate in the epi tian. We then remove some of the retrosigmoid bone and eggshell the bone over the sinus itself. We will then find the facial nerves that we can later do an efficient and safe larynx toy. We also typically drill a facial recess to access the eus station tube for later packing. Its relative position is shown here, we drill parallel to the facial nerve with a large diamond burr. Its outline will be shown later while we usually do a facial recess, this patience is very narrow. We therefore just remove the incus, drill down the incus buttress and visualize the station tube anteriorly in the depth. The relative positions of the semi circular canals and facial nerve are shown here for global reference. The endolymphatic sac will be in the posterior FASA pre sigmoid dura and the jugular bulb will dive deep under the facial nerve. We will perform a labyrinthectomy open the vestibule which is where the ampullae of the semi circular canals are located and then drill until we find the internal auditory canal or IC. The I AC will be in the depth. The middle fossa is then skeletonized with a large diamond burr and then decompressed with a bipolar bone is removed from the sigmoid sinus and the sinus itself is decompressed, shrinking it out of the way a bit. The sural angle and middle P Faid immediately are further skeletonized. The decompressed er is outlined here, we then show the outline of the labyrinth before commencing the labyrinthectomy, the inferior part of the lateral canal and the aula of the posterior canal come very close to the facial nerve. We start with the lateral canal, exposing the loin and leaving an inferior strut. So as not to damage the facial nerve, we then go parallel to the posterior canal lumen. As we get close to the facial nerve, we switch to a diamond, we then drill down a bit until we see the cross section of the lateral and posterior canals. The purple arrow will take us to the common cruise and superior canal. We decompress the posterior Faid dura and then expose a bit of superior canal lumen. The arrows show the direction of drilling to fully expose the superior canal lumen. We connect the superior and posterior canals and follow the superior canal anteriorly. This shows the outline of where the vestibule will be in relation to the facial. We accelerate some of the bone between the posterior canal and the back of the facial nerve. Once the vestibule is partially open, one can see the neurosensory epithelium, the ampullae of the superior and lateral canals converge to form Mike's dot behind which is the labyrinthine segment of the facial nerve, all bone behind the facial is removed and the vestibule is opened. Next, we look for the I AC. The Aula of the superior canal is a good landmark for the top of the I AC outlined in green. After finding the I ac we drill troughs on either side to facilitate tumor dissection. Bone is sequentially removed until the inferior shadow of the I AC comes into view. The trough is then drilled. We can now see the outline of the I ac dura a bit better and the superior trough has commenced. Generally, we try to skeletonize the IACC between 182 170 degrees to get full access to the tumor and nerves. Once paper thin, the bone is removed with the right angle and er Rosin guiding our dissection is the characteristic orientation of the cranial nerves within the I AC. The facial is usually intros superior, but we always use a nerve stimulator to confirm. We now see the whole I ac covered in dura, the dash lines mark our dural cuts and the drill flaps will then be reflected out. One must be careful anteriorly as an early take off of the labyrinthine facial can happen. The dur is incised with a small blade and then a right angle. The nerve stimulator is used to elevate the dural flap off the tumor, putting a micro pledget on top of the tumor and pulling down gently. We are able to develop a cleavage plane between the tumor and the surrounding nerves. We come upon the superior vestibular and cochlear nerves. First, we continue to develop the plane and see another nerve which is the facial. We confirm with the stimulator after we try for a bit to roll the tumor out. We realize we need to sacrifice the superior vestibular nerve to release it. We open the dura develop a cleavage plane and cut the nerve after confirming it's not the facial because our working space is a bit cramped and there's more extension into the CPA than anticipated. We open the poster, your FAA do. As shown, the door is again cut with a blade and opened with scissors. The inferior aspect of the tumor is rolled out and the same is done with the posterior aspect. The relationship of the tumor and the facial nerve in the I AC is shown some attachments are cut with a scissor on the tumor side. After lifting the tumor up, the facial is shown at the brain stem. The tumor is dissected off the nerve approximately and then taken off the metal segment with a micro dissector. After removing the small tumor, an IAB branch is seen to seal the cavity and prevent postoperative CS F leaks, small pieces of fat are placed under the dural leaflets to achieve a Champagne Cork effect. Small pieces are placed one after another until the deep cavity is filled. We then turn our attention to packing the eus station tube through the Antrim small pieces of fat and ser a cell are alternated into the middle ear and eus station tube until it is completely packed off. The surge cell helps to push the fat in the tensor timpani tendon can also be cut to get a little more visualization of the eus station tube if need be. Once the entire cavity is obliterated with fat fiber and glue is used to seal it. Mesh cranioplasty is then performed to better pack in the fat and help with cosmesis. The timpani membrane is then checked to ensure there is no perforation.
