Hernia-to-neck ratio is associated with emergent ventral hernia repair

The ratio of hernia size to fascial defect size, termed the hernia-to-neck ratio (HNR), has been proposed as a novel predictive factor for umbilical hernia complications. HNR ≥ 2.5 has been suggested to warrant surgery due to association with bowel strangulation, incarceration, and necrosis. The aim of this study was to evaluate the association between HNR and emergent ventral hernia repair at our institution.

A retrospective cohort study was performed of consecutive patients with ventral hernias evaluated at a large safety-net hospital from 2017 to 2019. Patients who required emergent ventral hernia repair were compared to patients who did not require repair at latest follow-up. HNR was calculated using a previously described method: maximal hernia sac size and maximal fascial defect size (termed "hernia neck size") were measured in the sagittal plane on CT scan. Data are described as mean ± standard deviation and median (interquartile range).

A total of 166 patients were included: 84 (51%) required emergent hernia repair and 82 (49%) did not undergo repair. Median follow-up was 19 (8-27) months. Patient groups were similar except the emergent repair group had more males (50% vs. 34%, p = 0.03), umbilical hernias (93% vs. 56%, p < 0.01), recurrent hernias (31% vs. 15%, p < 0.01), and lower mean BMI (34.3 ± 9.9 vs. 39.1 ± 6.5, p < 0.01). Hernia sac size did not differ between groups (5.8 [3.8-8.4] cm vs. 6.1 [3.5-11.8] cm, p = 0.45). Hernia neck size was significantly smaller in the emergent repair group (1.5 [2.3-3.5] cm vs. 3.4 [1.8-6.2] cm, p < 0.01). Hernia-to-neck ratio was significantly higher in the emergent repair group (2.4 [1.8-3.1] vs. 1.7 [1.1-2.9], p < 0.01).

This study demonstrated an association between higher HNR and increased risk of emergent ventral hernia repair. Future studies will evaluate the use of HNR to risk-stratify patients with ventral hernias in a safety-net hospital.