A randomized clinical trial (IOWISI) evaluated the effectiveness of intraoperative wound irrigation with polyhexanide 0.04% solution in preventing surgical site infections (SSIs) after laparotomy. The study included 689 patients undergoing open abdominal surgery, with 557 completing the trial. Patients were randomly assigned to three groups: polyhexanide irrigation, saline irrigation, or no irrigation. The primary outcome was SSI incidence within 30 days post-surgery, defined by the CDC. Overall, 11.8% of patients developed SSIs, with no significant difference between the three groups. Polyhexanide irrigation showed no statistically significant benefit over saline or no irrigation (hazard ratios 1.23 and 1.19, respectively). No significant differences were found in secondary outcomes, including hospital stay, reoperation rates, and adverse events. The study found that 92.8% of procedures were classified as level of contamination II, which may have influenced the results. The trial concluded that intraoperative wound irrigation with polyhexanide solution does not reduce SSI rates in clean-contaminated open abdominal procedures compared to saline or no irrigation. Additional trials are needed to assess the potential benefit of polyhexanide in contaminated and septic procedures. The study highlights the need for further research to evaluate the effectiveness of various irrigation solutions and surgical techniques in preventing SSIs. The results suggest that current practices may not be effective, and more evidence is required to guide clinical decisions. The study also emphasizes the importance of considering patient selection and surgical management in future trials.A randomized clinical trial (IOWISI) evaluated the effectiveness of intraoperative wound irrigation with polyhexanide 0.04% solution in preventing surgical site infections (SSIs) after laparotomy. The study included 689 patients undergoing open abdominal surgery, with 557 completing the trial. Patients were randomly assigned to three groups: polyhexanide irrigation, saline irrigation, or no irrigation. The primary outcome was SSI incidence within 30 days post-surgery, defined by the CDC. Overall, 11.8% of patients developed SSIs, with no significant difference between the three groups. Polyhexanide irrigation showed no statistically significant benefit over saline or no irrigation (hazard ratios 1.23 and 1.19, respectively). No significant differences were found in secondary outcomes, including hospital stay, reoperation rates, and adverse events. The study found that 92.8% of procedures were classified as level of contamination II, which may have influenced the results. The trial concluded that intraoperative wound irrigation with polyhexanide solution does not reduce SSI rates in clean-contaminated open abdominal procedures compared to saline or no irrigation. Additional trials are needed to assess the potential benefit of polyhexanide in contaminated and septic procedures. The study highlights the need for further research to evaluate the effectiveness of various irrigation solutions and surgical techniques in preventing SSIs. The results suggest that current practices may not be effective, and more evidence is required to guide clinical decisions. The study also emphasizes the importance of considering patient selection and surgical management in future trials.