Prophylactic slowly resorbable mesh in midline laparotomy to limit incisional hernia incidence: the prospective 'Mesh Augmented Reinforcement of Abdominal Wall Suture Line (MARS)' cohort study protocol.

Background: Incisional hernia (IH) after abdominal surgery is a frequent surgical complication. Risk factors associated with IH are midline incisions, patients with an abdominal aneurysm of the aorta, and high BMI. Preventive measures include the use of the small-bites suture technique and/or placing a prophylactic mesh for reinforcement of the midline closure. Although recommended for high-risk patients, many surgeons are still reluctant to place a prophylactic mesh due to related complications. To counter these concerns, new synthetic resorbable meshes are being developed, such as the Methods: The Mesh Augmented Reinforcement of Abdominal Wall Suture Line (MARS) study is a European, multicentre, prospective, single-arm study. A total of 120 patients scheduled for elective midline laparotomy, and for that reason at risk of developing IH, will be recruited in ~12 sites after informed consent. The sample size was estimated based on greater than 80% power, two-sided alpha of 0.05, an expected 12 month IH rate of 8% and a predefined performance goal of 18% (10% clinical margin). Midline incisions will be closed by the small bites closure technique with a minimum 4:1 suture-to-wound length ratio and reinforced by mesh placement in the retrorectus position. The primary outcome will be IH occurrence at 12-month postoperatively, evaluated both clinically and by ultrasound. Secondary outcomes will include mesh-related and postoperative complications, surgical characteristics, IH incidence at 2 and 3 years after surgery, and quality of life. Discussion: Currently, no conclusive evidence is available for synthetic resorbable meshes in a prophylactic setting to prevent IH. The MARS study will be the first prospective cohort study to investigate resorbable synthetic meshes and small bites closure to reduce IH incidence.