RESUMO
BACKGROUND: The use of mesh is the standard for the prevention of incisional hernia (IH). However, the effect of surgical site occurrence (SSO) has never been compared. The aim of this meta-analysis was to evaluate the prevalence of SSO and measure its negative effect through the calculation of the number needed to treat for net effect (NNT net). METHODS: A meta-analysis was performed according to the PRISMA guidelines. The primary objective was to determine the prevalence of SSO and IH, and the secondary objective was to determine the NNT net as a metric to measure the combined benefits and harms. Only published clinical trials were included. The risk of bias was analyzed, and the random effects model was used to determine statistical significance. RESULTS: A total of 15 studies comparing 2344 patients were included. The incidence of IH was significantly lower in the mesh group than in the control group, with an OR of 0.29 (95% CI 0.16-0.49, p = 0.0001). The incidence of SSO was higher in the mesh group than in the control group, with an OR of 1.21 (95% CI 0.85-1.72, p = 0.0001) but without statistical significance. Therefore, the way to compare the benefits and risks of each of the studies was done with the calculation of the NNT net, which is the average number of patients who need to be treated to see the benefit exceeding the harm by one event, and the result was 5, which is the average number of patients who need to be treated to see the benefit exceeding the harm by one event. CONCLUSION: The use of mesh reduces the prevalence of IH and it does not increases the prevalence of SSO, the NNT net determined that the use of mesh continues to be beneficial for the patient.