R.R. SHIGABUTDINOV², A.V. ZAKHAROVA¹,², D.M. MIRGASIMOVA¹,², S.G. GLEBASHEVA², D.Zh. VASILIEV² ¹Kazan State Medical University, 49 Butlerov St., Kazan, Russian Federation, 420012 ²Republican Clinical Hospital of the MH of RT, 138 Orenburgskiy Tract, Kazan, Russian Federation, 420064 Shigabutdinov R.R. — head of the department of endoscopy, tel. +7-917-267-31-56, e-mail: shigabutdinov1969@mail.ru Zakharova A.V. — Cand. Med. Sc., […]