Association between Duration of Neurosurgical Craniotomy and Surgical Site Infection: A Prospective Cohort Study.

OBJECTIVE: To quantify the dose-response relationship between the duration of neurosurgical craniotomy and the risk of surgical site infection (SSI), and to provide high-level evidence for optimizing perioperative infection prevention strategies. METHODS: A prospective cohort study was conducted among patients who underwent neurosurgical craniotomy in a tertiary grade A hospital from January 2021 to December 2022. Demographic data, underlying diseases, perioperative variables, and postoperative SSI outcomes were collected. Patients were divided into the SSI group (n = 68) and non-SSI group (n = 1197) based on the occurrence of SSI. Sample size was calculated using PASS software (version 15.0) with the following parameters: assumed SSI incidence of 5%, expected odds ratio (OR) of 1.2 for each 1-hour increase in surgical duration, α = 0.05, and β=0.8, confirming that 1265 participants provided sufficient statistical power. Multivariate logistic regression models (adjusted for confounding factors in three steps) were used to evaluate the association between surgical duration and SSI. Subgroup analyses were performed to explore potential effect modifiers. Restricted cubic spline (RCS) curves were applied to characterize the dose-response relationship. RESULTS: A total of 1265 eligible patients were enrolled, with an overall SSI incidence of 5.38% (68/1265). During follow-up, 63 patients were lost to follow-up, loss rate=4.98%, 0.05). RCS curves confirmed a significant linear dose-response relationship between surgical duration and SSI risk (P for overall<0.001, P for nonlinear=0.104), even after adjusting for all potential confounders. CONCLUSIONS: Surgical duration is an independent risk factor for SSI following neurosurgical craniotomy, with a significant linear association. Shortening surgical duration via optimized surgical planning (e.g., preoperative 3D reconstruction of skull lesions), improved surgical team collaboration (e.g., reducing instrument change time), and application of minimally invasive techniques (e.g., keyhole craniotomy), combined with strengthened perioperative infection control (e.g., strict sterile technique, intraoperative antibiotic redosing for surgeries exceeding 3 hours) and optimized perioperative management (e.g., maintaining normothermia, avoiding unnecessary blood transfusion), may effectively reduce SSI risk and improve patient outcomes.