1. Department of General, Endocrinological Surgery and Gastroenterological Oncology; Poznan University of Medical Sciences; Poznan Poland
2. Department of General Surgery; John Paul II Memorial Hospital; Belchatow Poland
3. Department of Thoracic Surgery; Poznan University of Medical Sciences; Poznan Poland
4. Department of General, Vascular and Oncologic Surgery; Regional Specialistic Hospital; Słupsk Poland