N. V. Levchenko
Khanty-Mansiysk State Medical Academy; The Nyagan District Hospital
Russian Federation

Nikolai V. Levchenko, MD, PhD, surgical doctor of the surgical department №1,NyaganDistrictHospital

V. V. Khryachkov
Khanty-Mansiysk State Medical Academy;
Russian Federation

Valerii V. Khryachkov, MD, PhD, DSc, professor of hospital surgery chair

R. R. Shavaliev
Khanty-Mansiysk State Medical Academy; The Nyagan District Hospital
Russian Federation

Rafael’ R. Shavaliev, surgical doctor of the surgical Department №1, The Nyagan District Hospital 

For correspondence: Address: 12 Zagorodnykh str., Nyagan’ 628181, Russian Federation

D. P. Kislitsin
Khanty-Mansiysk State Medical Academy; District Clinical Hospital
Russian Federation

Dmitrii P. Kislitsin, MD, PhD, associate professor, head of the department of hospital surgeryKhanty-MansiyskStateMedicalAcademy, head of the surgical department ofDistrictClinicalHospital, chief freelance surgeon of the department of health KHMAO-Yugra Tyumen region