Creation of a novel risk score for surgical site infection and occurrence after ventral hernia repair

Background: Complex ventral hernia repair (VHR) is a common surgical operation but carries a risk of complications from surgical site infections (SSI) and occurrences (SSO). We aimed to create a predictive risk score to identify patients at increased risk for SSO or SSI within 30 days of surgery. Methods: Data were prospectively collected on all patients undergoing VHR between January 2008 and February 2015 by a single surgeon. Multivariable logistic regression was used to identify independent factors predictive of SSO and SSI. Significant predictors of SSO and SSI were assigned point values based on their odds ratios to create a novel risk score, the Hopkins ventral hernia repair SSO/SSI risk score; predicted and actual rates of outcomes were then compared using weighted regression. Results: During the study period, 362 patients underwent open VHR. Thirty-day SSO and SSI occurred in 18.5 and 10% of patients, respectively. After risk adjustment, ASA class ≥3 (1 point), operative time ≥4 h (2 points), and the absence of a postoperative wound vacuum dressing (1 point) were predictive of 30-day SSO. Predicted risk of SSO utilizing this scoring system was 9.7, 19.4, 29.1, and 38.8% for 1, 2, 3, and 4 points (AUC = 0.73). For SSI, operative time ≥4 h (1 point) and the lack of a wound vacuum dressing (1 point) were predictive. Predicted risk of SSI based on this scoring system was 12.5% for 1 point and 25% for 2 points (AUC = 0.71). Actual vs. predicted rates of SSO and SSI correlated strongly for risk model with a coefficient of determination (R²) of 0.92 and 0.91, respectively. Conclusion: The novel Hopkins ventral hernia repair risk score accurately predicts risk of SSO and SSI after complex VHR. Further studies using a prospective randomized controlled trial will be needed to further validate our findings.