Alvarez et al.  observed that 13% of incarcerated groin hernia patients had undergone bowel resection surgery. Kurt et al.  reported that bowel resection was required in approximately 15% of patents with an incarcerated groin hernia. Suppiah et al.  revealed that emergency femoral hernia surgery had a higher rate of bowel resection than did elective femoral hernia surgery. Kemler et al.  reported that small bowel resection was required in up to 60% of patients with strangulated femoral hernias. Therefore, the rate of bowel resection is high in incarcerated groin hernia. In our study of 83 patients with incarcerated groin hernias 13 patents (15.7%) underwent bowel resection surgery.
It is very important to understand the preoperative condition of the incarcerated intestinal tract, information that is indispensable for deciding on the surgical technique, such as whether or not to resect the intestinal tract and whether or not to use mesh.
Chen et al.  reported in a meta-analysis that the total rate of resection was 21.0% (160/762) in the patients with incarcerated groin hernia. Eight factors were significantly related to the risk of bowel resection in their pooled analysis: female sex, femoral hernia, bowel obstruction duration of incarceration (hours), WBC count and neutrophilic leukocyte count. Our study indicated that CT attenuation of the incarcerated intestinal wall and the WBC count were significantly associated with the risk of bowel resection in incarcerated groin hernia patients.
In our study, we measured the CT value of the incarcerated intestinal wall at the fundus with the groin hernia patients and examined the need for intestinal resection retrospectively. The CT value is the image density value in a two-dimensional CT image. In recent years, there have been some reports on the utility of CT values in the field of abdominal emergency [14, 15]. Geffroy et al.  showed that increased unenhanced bowel-wall attenuation on 64-section multidirector CT had a useful sensitivity and high specificity for the diagnosis of bowel wall ischemia in a highly selected population of patients with surgically treated small bowel obstruction (SBO). Chuong et al.  showed that adding unenhanced images to contrast-enhanced images when performing CT to detect bowel wall ischemia based on the presence of decreased bowel wall enhancement in patents with SBO improved the sensitivity, level of confidence in assessing decreased bowl enhancement, and interobserver agreement. In our study, we measured the CT values of the incarcerated small intestine at the fundus by unenhanced CT at three locations (when possible, the mean values were extracted from the horizontal, coronal, and sagittal cross-sectional images). The average CT attenuation of the incarcerated small intestinal wall at the fundus was 20.65 ± 3.16 HU in the resection group and 28.12 ± 3.51 HU in the non-resection group. Significant differences were observed between two groups. The cut-off value for predicting intestinal resection was 25 HU (sensitivity: 0.923, specificity: 0.229, according to the examination of the ROC curve).
Inflammation indicators such as the WBC count, percentage of neutrophils, and neutrophil-to-lymphocyte ratio (NLR) were increased when incarcerated hernia evolved into a strangulated hernia [16–18]. These elevated inflammatory markers suggest a high risk of bowel necrosis, so emergency surgery should be performed immediately. In our study, regarding the WBC count, the cut-off count foe predicting intestinal resection was 11,550, (sensitivity: 0.769, specificity: 0.200, according to the examination of the ROC curve). A multivariate analysis showed that the odds ratio for the presence of intestinal resection was 10.153 (95% CI: 1.585 to 65.045) for the WBC count, making it an independent predictor of intestinal resection.
Our study indicated that CT attenuation of incarcerated intestinal wall and the WBC count were significantly associated with the risk of bowel resection in incarcerated groin hernia patients. Several limitations associated with the present study warrant mention. First, this was a retrospective study and our data are based on the medical examinations performed at our hospital. Selection bias therefore could not be completely avoided. Second, due to the single-center setting, this model requires further validation. Further large-scale and well-designed studies are needed.