1. Faculty of Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, ul. Jagiellonska 13/15, 85-090Bydgoszcz, Poland
2. Department of General and Oncological Pediatric Surgery, Antoni Jurasz University Hospital No. 1 in Bydgoszcz, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, ul. Marii Sklodowskiej- Curie 9, 85-094Bydgoszcz, Poland