Introduction: Any form of trauma, including surgery is known to result in oxidative stress. Single incision laparoscopy is a step forward towards almost scarless surgery. It is also expected to result in a lower degree of free radicals generation and faster normalization of the organism's antioxidant capacity.

Aim: The aim of the study was to assess a number of plasma oxidative stress markers in patients operated due to inguinal hernia using typical totally extra peritoneal (TEP) and modified single incision laparoscopic surgery (SILS) methods.

Material and methods: Thirty-two consecutive patients with no acute disease and severe chronic disorder, were qualified for inguinal hernia laparoscopic surgery. All were caucasian males, aged 24-69 and they underwent one of two surgical approaches: totally extra-peritoneal repair (TEP) and single incision laparoscopic surgery (SILS). TEP patients created Group 1 (n= 17) and SILS patients formed Group 2 (n= 17). Total antioxidant status (TAS) and thiobarbituric acid-reacting substances (TBARS) were determined in three time points: before, one day and four days after the laparoscopic surgery.

Thirty-two consecutive patients with no acute disease and severe chronic disorder were qualified for inguinal hernia laparoscopic surgery. All were caucasian males, aged 24-69 underwent one of two different surgical approaches: totally extra-peritoneal (TEP) repair and single incision laparoscopic surgery (SILS). TEP patients created Group 1 (n= 17) and SILS patients formed Group 2 (n= 17).

Blood Sampling and Biochemical Analysis Ulnar venous blood samples were collected from the participants three times (fasting, between 6:00 and 7:00 AM): before (0), one day (1) and four days (2) after laparoscopic surgery. Baseline (0) blood samples were used for routine pre-operative laboratory assessment, including complete blood count, basic coagulation tests, C-reactive protein, glucose and electrolytes levels. Total antioxidant status (TAS) and thiobarbituric acid-reacting substances (TBARS) were determined in three time points: 0, 1 and 2 as described above.

Spectrophotometry was used to measure TAS (RANDOX Laboratories, Crumlin, Antrim, UK) on Statfax 1904Plus (Awareness Technology, Palm City, FL) and TBARS according to the Okhawa method [11] (Sigma reagents, Germany) on Specord M40 (Carl-Zeiss, Germany). The intra- and inter-assay coefficients of variation were as follows: TAS (1.6 % and 3.7%), and TBARS (1.9% and 3.8%)

Inclusion Criteria:

• Patients with inguinal hernia.

Exclusion Criteria:

• Patients with acute disease and severe chronic disorder.