Table 2 Eligibility Criteria

• Patients of both sexes undergoing a primary elective median abdominal incision

• Patients with a known history of adhesion or peritonitis

• Age equal or greater than 18 years

• Patients with a known sensitivity to polyvinylalcohol or carboxy-methylcellulose

• Written informed consent

• Simultaneous participation in another clinical trial with interfering end-points

• Expected incison length ≥15 cm

• Emergency surgery

• Expected survival time more than12 months

• Patients with peritoneal carcinosis or peritoneal dialysis

• For female adults of reproductive potential: negative pregnancy test at visit 1 and sufficient contraception from time of written consent up to at least 4 months

• Patients with systemic immunsuppression (e.g. hydrocortisone >50 mg per daily, other immunsuppressants like Azathropin, Mycophenolatmofetil, Ciclosporin, Everolimus, Methotrexat ect.), chemotherapy or radiotherapy within the last 2 weeks prior surgery

• Patients with ascites >200 ml

• ASA > 3

• Patients with intra-abdominal abscess or other intra-abdominal infection

• Renal impairment (Creatinine >1.3 mg/ml)

• Pregnant or breast-feeding women

• Lack of compliance

• Surgical procedures or patients which require insertion more than 2 intra abdominal drains