Identifying predictors of ventral hernia recurrence: systematic review and meta-analysis.

BACKGROUND: Ventra hernias are increasing in prevalence and many recur despite attempted repair. To date, much of the literature is underpowered and divergent. As a result there is limited high quality evidence to inform surgeons succinctly which perioperative variables influence postoperative recurrence. This systematic review aimed to identify predictors of ventral hernia recurrence. METHODS: PubMed was searched for studies reporting prognostic data of ventral hernia recurrence between 1 January 1995 and 1 January 2018. Extracted data described hernia type (primary/incisional), definitions of recurrence, methods used to detect recurrence, duration of follow-up, and co-morbidity. Data were extracted for all potential predictors, estimates and thresholds described. Random-effects meta-analysis was used. Bias was assessed with a modified PROBAST (Prediction model Risk Of Bias ASsessment Tool). RESULTS: Screening of 18 214 abstracts yielded 274 individual studies for inclusion. Hernia recurrence was defined in 66 studies (24.1 per cent), using 41 different unstandardized definitions. Three patient variables (female sex, age 65 years or less, and BMI greater than 25, 30, 35 or 40 kg/m2), five patient co-morbidities (smoking, diabetes, chronic obstructive pulmonary disease, ASA grade III-IV, steroid use), two hernia-related variables (incisional/primary, recurrent/primary), six intraoperative variables (biological mesh, bridged repair, open versus laparoscopic surgery, suture versus mesh repair, onlay/retrorectus, intraperitoneal/retrorectus), and six postoperative variables (any complication, surgical-site occurrence, wound infection, seroma, haematoma, wound dehiscence) were identified as significant prognostic factors for hernia recurrence. CONCLUSION: This study summarized the current evidence base for predicting ventral hernia recurrence. Results should inform best practice and future research.

A systematic methodological review of non-randomised interventional studies of elective ventral hernia repair: clear definitions and a standardised minimum dataset are needed.

BACKGROUND: Ventral hernias (VHs) often recur after surgical repair and subsequent attempts at repair are especially challenging. Rigorous research to reduce recurrence is required but such studies must be well-designed and report representative and comprehensive outcomes. OBJECTIVE: We aimed to assesses methodological quality of non-randomised interventional studies of VH repair by systematic review. METHODS: We searched the indexed literature for non-randomised studies of interventions for VH repair, January 1995 to December 2017 inclusive. Each prospective study was coupled with a corresponding retrospective study using pre-specified criteria to provide matched, comparable groups. We applied a bespoke methodological tool for hernia trials by combining relevant items from existing published tools. Study introduction and rationale, design, participant inclusion criteria, reported outcomes, and statistical methods were assessed. RESULTS: Fifty studies (17,608 patients) were identified: 25 prospective and 25 retrospective. Overall, prospective studies scored marginally higher than retrospective studies for methodological quality, median score 17 (IQR: 14-18) versus 15 (IQR 12-18), respectively. For the sub-categories investigated, prospective studies achieved higher median scores for their, 'introduction', 'study design' and 'participants'. Surprisingly, no study stated that a protocol had been written in advance. Only 18 (36%) studies defined a primary outcome, and only 2 studies (4%) described a power calculation. No study referenced a standardised definition for VH recurrence and detection methods for recurrence varied widely. Methodological quality did not improve with publication year or increasing journal impact factor. CONCLUSION: Currently, non-randomised interventional studies of VH repair are methodologically poor. Clear outcome definitions and a standardised minimum dataset are needed.

Diagnostic utility of hepatitis E virus antigen-specific ELISA versus PCR testing in a cohort of post liver transplant patients in a large university hospital.

BACKGROUND: Hepatitis E virus (HEV) is an important infectious agent causing acute and chronic disease. Chronic hepatitis E affects immunocompromised people and serological testing is neither reliable nor sufficient to infer whether a patient has infection; therefore HEV RNA testing is the only reliable diagnostic test presently available. An HEV antigen-specific ELISA test is commercially available but is not yet in clinical use. OBJECTIVES: 1) determine the prevalence of HEV infection in the Royal Free Hospital (RFH) liver transplant cohort; 2) compare the diagnostic utility of HEV antigen-detection against the current gold standard; 3) consider screening strategies for HEV infection in immunocompromised groups. STUDY DESIGN: The serum samples of 490 post liver transplant patients visiting the outpatient clinic at the RFH over an eight-month period were tested for HEV with both an HEV antigen-specific ELISA and HEV RNA test. RESULTS: The prevalence of HEV infection was 0.20% (95% CI 0.0%-1.1%). The specificity of the ELISA was 98.2% with a positive predictive value of 10.0%. There was one true positive HEV case, which was picked up correctly by the antigen-specific ELISA. These results were improved by incorporating a neutralisation step into further ELISA tests. CONCLUSIONS: The antigen-specific ELISA test gave no false negative results, supporting its utility as a screening tool. There was one true antigen positive result. Further investigation including cost analysis is indicated to determine the efficacy of HEV antigen-specific ELISA testing in a screening context and in the clinical investigation of HEV infection in immunocompromised patients.