Aim of the project: The aim of this project is to prove reduced mortality, morbidity and hospitalization length (cost reduction) in prospective randomized study in patients treated due to severe peritonitis using VAC method in comparison to classical approach (primary closure of the abdominal cavity; secondary solution of complications). Secondary aim is to validate scoring systems and early sepsis markers (cytokines) in algorithm of assessment of severance of severe peritonitis in our conditions and their inclusion in indication for surgical revision. Tertiary aim is to determine group of patient who would profit the most from the method.