External Validation of the HERNIAscore: An Observational Study

Abstract

Background: The HERNIAscore is a ventral incisional hernia (VIH) risk assessment tool that uses only preoperative variables and predictable intraoperative variables. The aim of this study was to validate and modify, if needed, the HERNIAscore in an external dataset.

Study design: This was a retrospective observational study of all patients undergoing resection for gastrointestinal malignancy from 2011 through 2015 at a safety-net hospital. The primary end point was clinical postoperative VIH. Patients were stratified into low-risk, medium-risk, and high-risk groups based on HERNIAscore. A revised HERNIAscore was calculated with the addition of earlier abdominal operation as a categorical variable. Cox regression of incisional hernia with stratification by risk class was performed. Incidence rates of clinical VIH formation within each risk class were also calculated.

Results: Two hundred and forty-seven patents were enrolled. On Cox regression, in addition to the 3 variables of the HERNIAscore (BMI, COPD, and incision length), earlier abdominal operation was also predictive of VIH. The revised HERNIAscore demonstrated improved predictive accuracy for clinical VIH. Although the original HERNIAscore effectively stratified the risk of an incisional radiographic VIH developing, the revised HERNIAscore provided a statistically significant stratification for both clinical and radiographic VIHs in this patient cohort.

Conclusions: We have externally validated and improved the HERNIAscore. The revised HERNIAscore uses BMI, incision length, COPD, and earlier abdominal operation to predict risk of postoperative incisional hernia. Future research should assess methods to prevent incisional hernias in moderate-to-high risk patients.

Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

Cox proportional hazards regression model, stratified by HERNIAscore (Outcome: Clinical Hernia)

Figure 2

Cox proportional hazards regression model, stratified by HERNIAscore (Outcome: Radiographic Hernia)

Figure 3

Cox proportional hazards regression model, stratified by Revised HERNIAscore (Outcome: Clinical Hernia)

Figure 4

Cox proportional hazards regression models, stratified by Revised HERNIAscore (Outcome: Radiographic Hernia)