[Etiology of labyrinthine perilymphatic fistula].

The examination of 120 patients with verified labyrinthine fistulas (LFs) has demonstrated that perilymphatic LFs most often are caused by rupture of the cochlear window's membrane (54%). Among other reasons were broken base of the stapes (6%), the defect in the area of both windows (17%), rupture of the annular ligament of the stapes (15%), defects in the area of semicircular canals. Incompetence of the stapedial piston prosthesis is documented.