Patients and procedures
All patients must comply with a specific study protocol including the aforementioned bundle of preventive perioperative interventions for SSI: preoperative antibiotic prophylaxis following WHO specific recommendations [In the control group skin staples were used for dermal closure, with intervals of 10–15 mm. On the other hand, in the experimental group subcuticular suture was used, performing a continuous intradermal suture with 4/0 long-term absorbable monofilament material. In both groups abdominal fascia closure was performed with a continuous uninterrupted long-term absorbable suture (i.e., polydioxanone or polyglyconate) using “small-bites” technique. Subdermal layer (subcutaneous tissue) was closed when a depth ≥ 3 cm was found. For standardisation of all the procedures, both perioperative SSI prevention measures and incision closure procedure; staff surgeons were requested to learn the described interventions by means of specific lectures and reading a particular study protocol document provided by the investigators team. Furthermore, all participating surgeons were instructed to identify si-SSI according to CDC criteria [