Incidence of surgical site infection after craniotomy: comparison between three months and twelve months of epidemiological surveillance

Objective: To determine the incidence of surgical site infection in patients undergoing craniotomy and to compare 12-month and 3-month post-discharge surveillance periods in terms of their impact on the incidence of surgical site infection in those patients. Methods: This was a retrospective cohort study involving 173 adult patients submitted to “clean” craniotomy, with or without implants, during the six-month period, at a university hospital in the city of São Paulo, Brazil. All the patients were evaluated in the pre-, trans- and postoperative periods and were followed for 12 months to analyze the development of surgical site infections. Results: Of the 173 patients undergoing craniotomy during the study period, 20 developed an surgical site infection during the first, and 12 months after discharge, the overall incidence of surgical site infection therefore being 11.56%, compared with a 1-month incidence of 8.67% and a 3-month incidence of 10.98%. Among the 106 patients who received implants, the 1-, 3-, and 12-month incidence of surgical site infection was 7.54% (n = 8), 8.49% (n = 9), and 9.43% (n = 10), respectively. Among the 67 patients who did not receive implants, the 1-, 3-, and 12-month incidence of surgical site infection was 10.44% (n = 7), 14.92% (n = 10), and 14.92% (n = 10), respectively. Conclusion: The incidence of surgical site infection after craniotomy is high. Reducing the duration of the post-discharge surveillance period from 12 months to 3 months did not cause significant losses in the numbers of surgical site infection identified or a substantial decrease in their incidence.