Different etiopathogeneses in early-onset and late-onset inguinal hernia mesh infections in a prospectively evaluated cohort

Causation between the gut microbiota and inguinal hernia: a two-sample double-sided Mendelian randomization study

Inguinal hernias are the most common type of enterocele and are frequently caused by defects in the abdominal wall muscles in the groin area. Numerous animal models and human studies have shown that the gut microbiota is associated with skeletal muscle aging and loss. However, the causation between the gut microbiota and inguinal hernia remains unclear. To reveal the causal association between the gut microbiota and inguinal hernia, we conducted a two-sample double-sided Mendelian randomization analysis. We used genome-wide association analysis (GWAS) summary statistics of the gut microbiota from the MiBioGen consortium and GWAS statistics of inguinal hernia from the FinnGen R10 database. The causation between the gut microbiota and inguinal hernia was explored through the inverse variance weighted (IVW) method, MR Egger regression method, weighted median method, weighted model method, and simple model method. Sensitivity analysis was used to test whether the Mendelian randomization analysis results were reliable. Reverse Mendelian randomization was used to conduct effect analysis and sensitivity analysis using the entire gut microbiota as the outcome. The IVW results indicated that Verrucomicrobia, Lactobacilliales, Clostridiaceae1, Butyricococcus, Categorybacter, Hungatella, Odoribacter, and Olsenella had a direct negative causation with the gut microbiota. The reverse Mendelian Randomization results showed that Eubacterium brachygroup, Eubacterium eligensgroup, Eubacterium xylanophilumgroup, Coprococcus3, Ruminococcus1, and Senegalimassilia were directly related to inguinal hernia. The bilateral sensitivity analysis revealed no heterogeneity or horizontal pleiotropy. The results confirmed that 8 bacterial traits had a negative causation with inguinal hernia. Reverse MR analysis revealed a positive correlation between inguinal hernia and 6 bacterial traits. Modulating the diversity and components of the gut microbiota is envisaged to contribute to improving the incidence and prognosis of inguinal hernia.

Risk of Hernia Mesh Explantation following Early Versus Late Onset Skin and Soft Tissue Infection

To estimate the relative risk of explantation in patients with skin and soft tissue infection onset within 90 days of hernia surgery, compared with days 91-365 and after 1 year.

BACKGROUND

Infectious complications occurring after hernia repair with synthetic mesh require prolonged treatment, and eventual mesh explantation. Little is known whether early versus late onset infection is associated with differential risk of mesh removal, and whether treatment with long-term antibiotics or debridement are associated with mesh salvage.

METHODS

This was a retrospective observational cohort study. We obtained data on all inguinal, umbilical, and ventral hernia repairs with implanted synthetic mesh performed in Veterans Affairs hospitals during 2008-2015. Participants without a 5-year infection after hernia surgery were excluded. Logistic regression estimated the association of mesh explantation with exposure to mesh-related infection during postoperative days 0-90, versus days 91-365 versus after 1 year. Additional covariates included any subsequent abdominal operation, antibiotic administration, and incision and drainage (I&D) or debridement procedures.

RESULTS

One thousand eight hundred eighty-five patients underwent index hernia repair and developed a skin and soft tissue infection within 5 years. Infection onset during days 91-365 was associated with increased explantation risk (OR, 1.62; 95% CI, 1.04-2.48), as was increased antibiotic use (OR, 1.04; 95% CI, 1.03-1.05) and surgical treatments (OR, 3.74; 95% CI, 3.02-4.67). Subsequent abdominal operation was associated with lower explantation risk (OR, 0.46; 95% CI, 0.33-0.61).

CONCLUSIONS

Early infections may be more suitable for conservative management. Later-onset infections have lower probability of mesh salvage and should be considered for earlier explantation to save the patients prolonged courses of antibiotics and surgical interventions.

Delayed mesh infection after inguinal hernia repair: a case report

Delayed deep mesh infection is a rare complication and the precise mechanism of its development is unknown. We report a case of delayed deep mesh infection after inguinal hernia repair. A 65-year-old man was admitted for treatment of colon cancer. He had a history of bilateral hernioplasty repaired with mesh-plugs 6 years previously. Fluorine-18 fluorodeoxyglucose positron emission tomographic scan showed positive findings in the right inguinal region similar to cancer. He had no complaints or findings to suspect mesh infection. Postoperative computed tomography scan over time revealed a fluid collection with inflammation. Eleven years after hernia repair, the patient presented with inflammation in the right inguinal region and emergency operation was performed. An abscess cavity was found and the mesh-plug covered with granulation tissue was removed. The patient remains free of recurrence of inguinal hernia or inflammatory changes after 3 years of follow-up.