Selective vestibular ablation by KTP laser in endolymphatic hydrops

Objectives and hypothesis: Vertigo, the cause of disability in many patient s with Meniere's disease, may be the result of the effects of endolymphatic hydrops on the semicircular canals, We hypothesize that intractable vertig o may be controlled by destruction of the semicircular canal neuroepitheliu m using visible light lasers without the need for extensive fenestration of the bony labyrinth, This study was designed to assess the cochlear effects of potassium titanyl phosphate (KTP) laser-assisted triple semicircular ca nal ablation (TSCA) in endolymphatic hydrops, Study Design: Randomized, pro spective, and controlled. Methods: Forty-one adult guinea pigs underwent ei ther a unilateral endolymphatic duct occlusion to induce hydrops or a sham procedure, Ten weeks after induction of the hydrops, a KTP laser-assisted T SCA or a sham surgery was performed. Results: Electrocochleographic thresho lds to clicks and tone-bursts (2-20 kHz) did not change significantly up to 4 weeks after TSCA in hydropic ears. Cross-sectional histology confirmed t he presence of hydrops and the ablation of the semicircular canals, Cochlea r whole-mounts for hair cell counts showed no significant loss of outer or inner hair cells in hydropic ears treated with TSCA. Conclusion: KTP laser- assisted TSCA can be performed in the guinea pig model of endolymphatic hyd rops without significant loss of hearing. Evaluation of this technique may be warranted in patients with intractable Meniere's disease.