Complex abdominal wall hernia repair with biologic mesh in elderly: a propensity matched analysis.

BACKGROUND: Complex abdominal wall reconstruction (CAWR) has become a common surgical procedure both in non-elderly and elderly patients. OBJECTIVE: The aim of this study is to analyze the outcomes of the elderly compared to nonelderly undergoing CAWR using propensity score matching. METHODS: All patients who underwent CAWR using porcine-derived, non-crosslinked acellular dermal matrix (ADM) (Strattice™) between January 2014 and July 2017 were studied retrospectively. Propensity matched analysis was performed for risk adjustment in multivariable analysis and for one-to-one matching. The outcomes were analyzed for differences in postoperative complications, reoperations, mortality, hospital length of stay and adverse discharge disposition. RESULTS: One hundred-thirty-six patients were identified during the study period. Non-elderly (aged 18-64 years) constituted 70% (n = 95) and elderly (aged ≥ 65 years) comprised 30% of the overall patient population (n = 41). Seventy-three (56.7%) were females. After adjustment through the propensity score, which included 35 pairs, the surgical site infection (p = 1.000), wound necrosis (p = 1.000), the need for mechanical ventilation (p = 0.259), mortality (p = 0.083), reoperation rate (p = 0.141), hospital length of stay (p = 0.206), and discharge disposition (p = 0.795) were similar. CONCLUSION: Elderly patients undergoing CAWR with biological mesh have comparable outcomes with non-elderly patients when using propensity matching score.

A novel tool to evaluate bias in literature on use of biologic mesh in abdominal wall hernia repair.

PURPOSE: Biologic meshes are being increasingly used for abdominal hernia repair in high-risk patients or patients with a previous history of wound infection, due to their infection-resistant properties. Several studies have been carried out to assess whether biologic mesh is superior to synthetic mesh, as well as to establish guidelines for their use. Unfortunately, most of these studies were not rigorously designed and were vulnerable to different types of bias. The systematic reviews that have been published so far on this topic contain the same biases and limitations of the primary articles that are analyzed. The lack of a literature review on the bias on the use of biological mesh prompted us to conduct the literature search, assessment and plan this article. METHODS: We performed a literature search in PubMed, Embase and Cochrane databases of systematic reviews on biologic mesh for ventral hernia repair. The literature review was conducted using the Population, Intervention, Comparisons, Outcomes and Design approach. We identified 40 studies that matched the stringent criteria we had set. We then created a 13-point instrument to assess for bias and applied it on the primary studies that we intended to analyze. RESULTS: Most primary studies are case series or case reports of patients undergoing abdominal hernia repair with biologic mesh, without any comparison group, and the inclusion of cases was only specified to be consecutive in 6 out of 40 cases. In terms of assessing outcomes, in none of the 40 articles were the outcome assessors blinded to the intervention or exposure status of participants. CONCLUSION: The instrument that we created could allow to assess the risk of bias in different kind of studies. Our assessment of the studies based on the criteria that we had set up in the instrument clearly identified that further research needs to be done due to the lack of unbiased studies regarding the use of biologic meshes for abdominal hernia repair.

Recurrence of infection and hernia following partial versus complete removal of infected hernia mesh: a systematic review and cohort meta-analysis.

BACKGROUND: The aim of this systematic review and meta-analysis was to determine whether complete removal of infected hernia mesh (CMR) provides better results as compared to partial removal (PMR). METHODS: PubMed, EMBASE, Cochrane Library, and MEDLINE via Ovid were systematically searched for records published from 1980 to 2018 by three independent researchers (GM, GS, and GG). Quality assessment, data extraction and analysis were performed according to the Cochrane Handbook for Systematic Reviews of Interventions. Mantel-Haenszel method with odds ratio and 95% confidence interval (OR (95% CI)) as the measure of effect size of dichotomous primary and secondary endpoints was utilized. Random-effects model was used for meta-analysis. RESULTS: Five observational studies totaling 421 patients were included in the meta-analysis. Rates of infection recurrence were 58.5% (62/106) in PMR and 25.5% (62/315) in CMR. The difference was statistically significant [OR (95% CI) 4.15 (2.30, 7.47); p < 0.001]. Rates of hernia recurrence were 9.7% (8/82) in PMR vs. 40.2% (41/102) in CMR. This difference was not statistically significant [OR (95% CI) 0.25 (0.04, 1.62); p = 0.15]. Low risk of publication bias was found using funnel plots and Egger's test. CONCLUSIONS: This meta-analysis found significantly increased rates of infection recurrence in patients undergoing partial removal of infected hernia mesh as compared to complete removal. Complete removal of infected hernia mesh may be associated with increased rates of hernia recurrence. Further longitudinal observational studies are needed to confirm these findings.