Background: Umbilical hernia is a common pathology and surgical repair is advised to prevent complications in symptomatic patients. However, risk factors that predict such advert events are unknown. The aim of the study was to determine whether morphological characteristics are associated with the occurrence of complications.
Method: Retrospective review of adult patients with elective and emergent umbilical hernia repair operated from January 2004 to December 2013. The size of the hernia and the size of the neck were measured based on operative reports, ultrasound, CT or MRI images. The Hernia-Neck-Ratio (HNR) was then calculated as novel risk indicator.
Results: 106 patients underwent umbilical hernia repair (70 for uncomplicated and 36 for complicated hernia) as single procedure. The median size of the hernia sac was statistically significantly smaller in the uncomplicated group (30 mm, interquartile range (IQR) 20-49 vs. 50 mm, IQR 40-71, p = 0.037). The median size of the neck was not different between both groups (15 mm, IQR 11-29 vs. 16 mm, IQR 12-21, p = 0.44). The median HNR was smaller in the uncomplicated group (1.76, IQR 1.45-2.18 vs. 3.33, IQR 2.97-3.91, p = 0.00026). Based on ROC curve analysis (area under the curve: 0.9038), a cut-off value of 2.5 was associated with 91 % sensitivity and 84 % specificity.
Conclusions: A novel predictive factor for complications related to umbilical hernia is proposed. The Hernia-Neck Ratio can easily be calculated. These results suggest that umbilical hernia with HNR >2.5 should be operated, irrespective of the presence of symptoms.