O41 – External Validation of the Ventral Hernia Risk Score for Predicting Surgical Site Infections

Author(s):

Mike Liang, Lillian Kao, Robert Martindale, Scott Roth, University of Texas Health Sciences Center

Background: Previously, we reported that the Ventral Hernia Risk Score (VHRS) was more accurate in predicting surgical site infection (SSI) following open ventral hernia repair than other models such as the Ventral Hernia Working Group (VHWG) model in a Veterans Affairs population. VHRS was developed based on single-center data and stratifies SSI risk into five groups based on concomitant hernia repair, skin flaps created, American Society of Anesthesiologists score ≥ 3, body mass index ≥ 40 kg/m2, and wound class 4. The purpose of this study was to externally validate the VHRS in a two-institution cohort.

Hypothesis: The VHRS has greater predictive accuracy of SSI following open ventral hernia repair compared to VHWG grade.

Methods: A mixed prospective and retrospective database of all open ventral hernia repairs performed at two institutions from 2009-2012 was utilized. All patients with a follow-up of at least 1 month were included. The Center for Disease Control definition of SSI was utilized. Each patient was assigned a ventral hernia risk score and ventral hernia working group classification. Receiver operator characteristic curves (ROC) were used to assess predictive accuracy and the areas under the curve (AUCs) were compared between the two models.

Results: A total of 311 patients underwent open ventral hernia repair; 69 (22.2%) patients developed a SSI. AUC of the VHRS (0.80) was greater than that of the VHWG (0.77); however both were highly accurate in predicting SSI.

Conclusions: The VHRS provides a novel, externally validate risk assessment score of a patient’s likelihood to develop a SSI following open ventral hernia repair. Although the VHRS was developed in a Veterans Affairs population of largely high-risk, older men, this data provides evidence that the VHRS is generalizable to other populations. Elevating skin flaps, ASA score 3 or 4 patients, performing concomitant procedures, morbid obesity, and wound class all independently predict the likelihood of SSI. It remains to be seen if preoperative risk reduction, intra-operative surgical technique, and postoperative management can improve outcomes in the highest risk patients.