An incarcerated hernia is the entrapment of abdominal tissue within the hernial sac. The risk of strangulation due to incarceration increases as the emergency surgery is delayed. Perforation and sepsis may develop secondary to necrosis, leading to a life-threatening clinical situation .
Comorbid diseases and postoperative mortality increase with age . In this study, the mean age of the resection group was higher than that of the non-resection group, while the rate of femoral hernia was lower. Both of these results contradict some reported literature data [16, 17]. This is thought to be due to the fact that elective inguinal hernia surgeries may have been postponed due to the number of increased comorbid diseases with age and the COVID-19 pandemic.
Previous studies have reported that emergency hernia surgery was performed more frequently in men and bowel necrosis was higher in women. In the current study, emergency hernia repair and bowel resection were performed more frequently in male patients [21, 22]. The rate of mesh use was significantly higher in group-2 patients who did not underwent bowel resection (p < 0.0001). This can be attributed to not preferring the use of mesh in group-1 patients due to the risk of infection by the surgeon.
In the present study, the rate of performing bowel resection was 34.1% among patients with IIH who underwent emergency surgery, and the mortality rate was 7.6%, which was higher than those reported in the literature [1, 16]. This high mortality rate may be due to the fact that our hospital is a tertiary referral center serving a population of 4,5 million where complicated patients are referred for management, and that the study period covers approximately 1.5 years of the COVID-19 pandemic when hospital admissions were delayed [1, 23].
In the case of inflammation, an increase in neutrophil count, accordingly associated lymphopenia, and an increase in CRP levels are expected . Most of the previous studies conducted to predict bowel necrosis have focused on acute mesenteric ischemia, reporting that CRP, WBC, and NLR values are significant for prognosis [24, 25]. Performing bowel resection for necrosis in incarcerated hernias increases postoperative morbidity and length of hospital stay, as in our study .
The present study demonstrates the feasibility of a novel biomarker, DRR, as an inflammatory biomarker for early prediction of bowel necrosis in patients with IIH, unlike the literature data reported so far. In addition to DRR, the resection group had significantly different WBC, CRP, NLR, PLR, LMR, LCR values, which is consistent with the literature data.
In some studies, an increased DRR has been associated with the prognosis of urothelial carcinoma, cholangiocarcinoma, renal cell carcinoma, gastric adenocarcinoma, head and neck cancer [26–31]. Cancer cells exhibit a higher rate of aerobic glycolysis in order to multiply faster than normal cells . AST plays an essential role in the mitochondrial displacement of nicotinamide adenine dinucleotide hydrogen in aerobic glycolysis via the malate aspartate shuttle . Therefore, an increase is observed in AST activation of fast-growing tissues such as cancer cells . Some studies have also used DRR to predict the risk of liver fibrosis and liver damage secondary to the hepatitis C virus [34, 35].
Weng et. al. found that an increased DRR was independently associated with the risk of developing cardiovascular disease, especially in men . An elevated serum AST level is also an important marker in systemic conditions such as metabolic syndrome, sarcopenia, and increased oxidative stress, which are risk factors for mortality apart from liver damage . Elinav et. al. found a decrease in ALT levels, especially in men over 70 years of age, throughout a 12-year follow-up period, reporting that it was significantly associated with mortality, although multivariate regression analysis revealed that diabetes, chronic renal failure, and malignancy were strong predictors of mortality .
We think that the higher male ratio and the higher mean age of patients in the resection group than the non-resection group in the present study may be associated with increased DRR, which is in line with the literature data indicating that ALT values may be decreased in the male gender and elderly population .
Although we cannot clearly reveal the underlying mechanism of increased DRR for predicting intestinal necrosis in the light of the literature, we can consider that the development of intestinal necrosis may have triggered the dysfunction of the hepatic inflammatory pathway activated by catecholamines at the mitochondrial level, leading to liver damage with increased oxidative stress [39, 40].
This study has some limitations. First, the study has a retrospective design. Second, it was not known whether the patients included in the study had a history of liver disease. However, this study is the first to propose that the De Ritis ratio can be used as a predictor of bowel necrosis in incarcerated inguinal hernias. In this sense, we believe that our work is valuable.