The safety of applying A-Part® Gel intra-peritoneally under the incision in order to prevent post-surgical adhesions after median laparotomy.

Primary Objective:

• first assessment of the safety of applying A-Part® Gel as adhesion prophylaxis after major abdominal surgery by specific observation of two major complications of abdominal surgery (wound healing impairment, and/or postoperative peritonitis) in comparison to a control group.

Secondary Objectives:

• To further evaluate the safety of A-Part® Gel by comparing the incidences of adverse events between the treatment groups (with special attention to anastomosis leakage)
• To explore the efficacy of A-Part® Gel in reducing post-surgical adhesions after median laparotomy

Inclusion Criteria:

• Patients of both sexes, who are candidates for a primary and elective median abdominal incision with a length of ≥ 15 cm 2.
• Age ≥ 18 years
• Patients who are legally capable and able to understand the nature, significance and consequences of the study and are willing and able to comply with the study protocol and the follow up
• Written informed consent obtained according to international guidelines and local law. Informed consent will be documented by the volunteer's dated signature, which will be also signed and dated by the investigator
• Patients with an expected survival time >12 months
• 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

Exclusion Criteria:

• Patients with a previous median laparotomy and any other abdominal surgery (exceptions: previous laparoscopic appendectomy, cholecystectomy, inguinal hernia repair, gynecological tube sterilisation)
• Patients with a known history of adhesions or a known history of peritonitis
• Patients with a known sensitivity to polyvinylalcohol and/or carboxymethylcellulose
• Simultaneous participation of the patient in another clinical trial or participation in a clinical trial within the last 30 days prior to signing the Informed consent form
• Patients with ASA > 3 or emergency patients (including severe psychic diesease)
• Patients with ascites > 200 ml
• Patients with peritoneal carcinosis or peritoneal dialysis
• Patients with a diagnosed peritonitis, intra-abdominal abscess or other intra-abdominal infection
• Patient with renal impairment (Creatinine > 1.3 mg/dl)
• Patients with systemic immunosuppression (e.g. hydrocortisone > 50mg daily [oral/i.v.] at any day or any equivalent dosage; other immunosuppressants like Azathioprin, Mycophenolatmofetil, Ciclosporin, Everolimus, Methotrexat, ect.), chemotherapy or radiotherapy within the last 2 weeks prior to surgery
• Surgical procedures or patient characteristics which require insertion of more than 2 intra-abdominal drainages
• Women within a pregnancy or breast-feeding mothers or women who wish to get pregnant within the next 4 months after surgery or women without sufficient contraceptive care