2.2. Patients
All the patients underwent PSD surgery in our secondary level state hospital between 01.01.2013 and 31.12.2017, were evaluated for eligibility. The patients with missing data, under 18 years old age, who had any immune system disease, and who were treated other treatment procedures, were excluded from the study. The patients underwent either SPC or EPC surgery was included in the study. The authors did not involve in the selection of the surgery type of the patient. The patients’ initial, perioperative and follow-up data were gathered from the electronic health records.