T.R. BATYRSHIN1, V.A. ABDULYANOV2, R.G. BATYRSHIN3 1Kazan State Medical Academy, 36 Butlerov St., Kazan, Russian Federation, 420012 2Kazan State Medical University, 49 Butlerov St., Kazan, Russian Federation, 420012 3City Clinical Hospital № 16, 121 Gagarin St., Kazan, Russian Federation, 420038 Batyrshin T.R. — PhD (Medicine), Associate Professor of the Department of Otorhinolaryngology, tel. +7-905-319-93-37, e-mail: […]