Influence of ambient air pressure changes on vestibular symptoms after stapes surgery.

OBJECTIVE: To examine if vestibular irritation after stapes surgery may be provoked by pressure changes across the tympanic membrane, which consecutively results in displacements of the ossicular chain and the piston prosthesis suspended to it. METHODS: In this prospective study 15 patients (13 female, 2 male) received unilateral stapes surgery (4 left, 11 right ear) with stapedotomy (n=14) or stapedectomy (n=1) at an academic tertiary referral center. Surgery was performed under local anesthesia via a transmeatal approach with a piston prosthesis 0.4×4.5mm. The fixation of the stapes, the exclusion of a malleus head fixation, and the gliding capacity of the malleus-incus joint were examined intraoperatively. A pure tone audiogram at four frequencies, a tympanometry with simultaneous video-oculography (VOG), caloric testing, and posturography with and without simultaneous tympanometry were performed six days before surgery, six weeks and three months after surgery, respectively. RESULTS: The mean air bone gap improved significantly from 25 (±8) dB preoperatively to 10 (±6) dB after surgery. In the tympanometry with simultaneous VOG only two patients showed nystagmus beats into the operated ears during only one of the two follow-up appointments. All other patients did not show any vestibular symptoms or nystagmus during any of the follow-up appointments. In the combined testing of posturography and tympanometry no patient showed any pathological findings. CONCLUSION: In patients who underwent stapes surgery with a piston prosthesis no vestibular symptoms can be provoked by pressure changes in the external auditory canal.