The closed systems, such as conventional negative pressure wound therapy (NPWT), were usually avoided in infected or critical colonized wounds. To our observation, the additional continuous irrigation tube attached beside the suction tube in the NPWT system could provide the effective drainage by reducing the occlusion of suction tube, enable effective debridement by diluting infected/necrotized tissues and decrease the incidence of fistula by providing relatively moist ambient. At our institutions, the modified system combined with a "triple-tube" device to allow a continuous instillation became more active and efficient. The study is to investigate if a continuous triple-tube instillation and suction could improve the outcomes of acute severely infected open abdomen.