January 17, 2015
Selective Vestibular Neurotomy can be quite effective in patients with a Meniere's Disease who have been correctly selected for this procedure. Let's go ahead and review technical nuances for this operation. This is a patient of mine, a 41 year-old female with intractable disabling vertigo and tinnitus in the right ear, who previously underwent multiple previous treatments as it is pretty typical of these patients. Due to her disabling features of her vertigo and other symptoms, she underwent a right-sided retromastoid craniotomy. These patients often undergo a number of different procedures, including a mastoid shunt and incision has to take into account, their previous incisions behind their ear to assure that the healing process is adequate for the incision. You can see the position of the sigmoid and transverse sinuses, the root of zygoma, the inion line across these two describes the transverse sinus, and here's the mastoid groove. We went ahead in this case with an S-incision, although I typically use the curvilinear incision as described previously. Here's the craniotomy, the sigmoid sinuses partially exposed, the dural has been opened along the transverse and sigmoid sinuses, and here's the junction between the tentorium and the petrous bone. I used the same trajectory as the one used for trigeminal neuralgia. You can see the seventh and eighth cranial nerves are exposed. The brainstem auditory evoked potentials are monitored here. Here's the exposure of the eighth cranial nerve as you can see all the reclining membranes have been widely open to prevent any traction on the eighth cranial nerve. Typically, the vestibular or primarily the superior vestibular portion of the nerve is slightly more grayish than the cochlear part of the nerve, which is very inferior. Also, there is an arterial that divides these two components or creates a distinction between these two components. And you can also often appreciate a plane between the two that is actually a real plane. And that's how we can differentiate between the primarily vestibular component, which is superior and the cochlear component, which is inferior. We go ahead and use the blunt dissector to gently dissect these two components. Gentle retraction can potentially expose the labyrinthine artery and the facial nerve. Here you can see the plane is clearly present between the vestibular and cochlear portions. We use angled sharp micro scissor to go ahead and cut the vestibular component of the nerve. Again, you have to be very careful to preserve the labyrinthine artery and the facial nerve, both of which are anterior. We cut the nerve in layers just to be on the safe side. Ultimately, the dissector confirms that the nerve is completely transected and no injury has occurred to the anterior structures. Thank you.
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