A.A. GRIGORYEVA1, A.I. PROSKURIN2, E.B. DORZHINOVA3 1Astrakhan branch of Scientific-Clinical Center for Otorhinolaryngology of ФМБА of Russia, 2 Tatishchev Str, Astrakhan, Russian Federation, 414056 2Astrakhan State Medical University, 121 Bakinskaya Str., Astrakhan, Russian Federation, 414000 3Respublican Hospital named after P.P. Zhemchuyev, 52 Pushkin Str., Elista, Republic of Kalmykia, Russian Federation, 358009 Grigorieva A.A. — PhD […]