Can Hernia Sac to Abdominal Cavity Volume Ratio Predict the Fascial Closure Rate for Large Ventral Hernia? The Reliability of the Tanaka Score.

Background The hernia sac to abdominal cavity volume ratio (VR) on abdominal CT was described previously as a way to predict which hernias would be less likely to achieve fascial closure. The aim of this study was to test the reliability of the previously described cutoff ratio in predicting fascial closure in a cohort of patients with large ventral hernias. Methods Patients who underwent elective, open incisional hernia repair of 18 cm or larger width at a single center were identified. The primary end point of interest was fascial closure for all patients. Secondary outcomes included operative details and abdominal wall-specific quality-of-life metrics. We used VR as a comparison variable and calculated the test characteristics (ie, sensitivity, specificity, and positive and negative predictive values). Results A total of 438 patients were included, of which 337 (77%) had complete fascial closure and 101 (23%) had incomplete fascial closure. The VR cutoff of 25% had a sensitivity of 76% (95% CI, 71% to 80%), specificity of 64% (95% CI, 54% to 74%), positive predictive value of 88% (95% CI, 83% to 91%), and negative predictive value of 45% (95% CI, 36% to 53%). The incomplete fascial closure group had significantly lower quality of life scores at 1 year (83.3 vs 52.5; p = 0.001), 2 years (85 vs 33.3; p = 0.003), and 3 years (86.7 vs 63.3; p = 0.049). Conclusions In our study, the VR cutoff of 25% was sensitive for predicting complete fascial closure for patients with ratios below this threshold. Although there is a higher likelihood of incomplete fascial closure when VR is ≥ 25%, this end point cannot be predicted reliably. Additional studies should be done to study this ratio in conjunction with other hernia-related variables to better predict this important surgical end point.