Multicenter, Prospective, Longitudinal Study of the Recurrence, Surgical Site Infection, and Quality of Life After Contaminated Ventral Hernia Repair Using Biosynthetic Absorbable Mesh: The COBRA Study

OBJECTIVE: The aim of the study was to evaluate biosynthetic absorbable mesh in single-staged contaminated (Centers for Disease Control class II and III) ventral hernia (CVH) repair over 24 months. BACKGROUND: CVH has an increased risk of postoperative infection. CVH repair with synthetic or biologic meshes has reported chronic biomaterial infections and high hernia recurrence rates. METHODS: Patients with a contaminated or clean-contaminated operative field and a hernia defect at least 9 cm had a biosynthetic mesh (open, sublay, retrorectus, or intraperitoneal) repair with fascial closure (n = 104). Endpoints included overall Kaplan-Meier estimates for hernia recurrence and postoperative wound infection rates at 24 months, and the EQ-5D and Short Form 12 Health Survey (SF-12). Analyses were conducted on the intent-to-treat population, and health outcome measures evaluated using paired t tests. RESULTS: Patients had a mean age of 58 years, body mass index of 28 kg/m, 77% had contaminated wounds, and 84% completed 24-months follow-up. Concomitant procedures included fistula takedown (n = 24) or removal of infected previously placed mesh (n = 29). Hernia recurrence rate was 17% (n = 16). At the time of CVH repair, intraperitoneal placement of the biosynthetic mesh significantly increased the risk of recurrences (P ≤ 0.04). Surgical site infections (19/104) led to higher risk of recurrence (P < 0.01). Mean 24-month EQ-5D (index and visual analogue) and SF-12 physical component and mental scores improved from baseline (P < 0.05). CONCLUSIONS: In this prospective longitudinal study, biosynthetic absorbable mesh showed efficacy in terms of long-term recurrence and quality of life for CVH repair patients and offers an alternative to biologic and permanent synthetic meshes in these complex situations

Prospective, multicenter study of P4HB (Phasix™) mesh for hernia repair in cohort at risk for complications: 3-Year follow-up

Background: This study represents a prospective, multicenter, open-label study to assess the safety, performance, and outcomes of poly-4-hydroxybutyrate (P4HB, Phasix™) mesh for primary ventral, primary incisional, or multiply-recurrent hernia in subjects at risk for complications. This study reports 3-year clinical outcomes. Materials and methods: P4HB mesh was implanted in 121 patients via retrorectus or onlay technique. Physical exam and/or quality of life surveys were completed at 1, 3, 6,12, 18, 24, and 36 months, with 5-year (60-month) follow-up ongoing. Results: A total of n = 121 patients were implanted with P4HB mesh (n = 75 (62%) female) with a mean age of 54.7 ± 12.0 years and mean BMI of 32.2 ± 4.5 kg/m2 (±standard deviation). Comorbidities included: obesity (78.5%), active smokers (23.1%), COPD (28.1%), diabetes mellitus (33.1%), immunosuppression (8.3%), coronary artery disease (21.5%), chronic corticosteroid use (5.0%), hypo-albuminemia (2.5%), advanced age (5.0%), and renal insufficiency (0.8%). Hernias were repaired via retrorectus (n = 45, 37.2% with myofascial release (MR) or n = 43, 35.5% without MR), onlay (n = 8, 6.6% with MR or n = 24, 19.8% without MR), or not reported (n = 1, 0.8%). 82 patients (67.8%) completed 36-month follow-up. 17 patients (17.9% ± 0.4%) experienced hernia recurrence at 3 years, with n = 9 in the retrorectus group and n = 8 in the onlay group. SSI (n = 11) occurred in 9.3% ± 0.03% of patients. Conclusions: Long-term outcomes following ventral hernia repair with P4HB mesh demonstrate low recurrence rates at 3-year (36-month) postoperative time frame with no patients developing late mesh complications or requiring mesh removal. 5-year (60-month) follow-up is ongoing

Optimizing choledocholithiasis management: a Cost-effectiveness analysis

Hypothesis: Endoscopic retrograde cholangiopancreatography (ERCP) is more cost-effective for managing incidental choledocholithiasis (CDL) after laparoscopic cholecystectomy and intraoperative cholangiogram (LC/IOC) than laparoscopic common bile duct exploration (LCBDE). Design A cost-effectiveness analysis was performed to compare ERCP with LCBDE. Sensitivity analyses were performed to determine the key contributors to cost-effectiveness between the 2 treatment options. Setting Costs were approached from the institutional perspective considering a typical patient undergoing LC/IOC at a large referral center. Patients The base case patient evaluated was a woman 18 years of age or older with symptomatic cholelithiasis and incidental CDL discovered at the time of LC/IOC. Interventions Endoscopic retrograde cholangiopancreatography with drainage procedure performed after LC/IOC or LCBDE during LC/IOC. Main Outcome Measures Costs, quality-adjusted life years gained, mean cost-effectiveness ratios, and incremental cost-effectiveness ratios. Results: In the base case analysis, ERCP was the optimal treatment choice with a cost of $24 300 for 0.9 quality-adjusted life years gained compared with$28 400 and 0.88 quality-adjusted life years for LCBDE. Endoscopic retrograde cholangiopancreatography remained the optimal strategy for CDL in multiway probabilistic sensitivity analysis. If LCBDE were performed and the cost of a potential operative case lost was $3100 or less and the cost of ERCP hospitalization was$18 000 or more, then LCBDE became the preferred treatment for CDL. Conclusions: Endoscopic retrograde cholangiopancreatography was both less costly and more effective than LCBDE. Factors important to choosing the best strategy for CDL management included the cost of a potential case lost due to LCBDE performance and the cost of ERCP hospitalization

Flavour-changing top quark decays in the alternative left-right model

We examine flavour-changing neutral-current decays of the top quark, t→qγ, t→qZ, t→qH, and t→qg (with q=u,c), in the Alternative Left-Right Model, a left right-symmetric model featuring exotic quarks and light bosons. These decays have a very small probability of occurring within the Standard Model, but they can be enhanced in this model through the presence of the exotic states. While associated signals may be detected directly at the LHC, rare decays have the advantage of offering means to probe new particles indirectly, through loop-contributions. We perform a comprehensive analysis of the model's parameter space to demonstrate the possible existence of enhancements in the corresponding branching ratios, of 106 for the branching ratios B(t→uZ) and B(t→uH), and in the range of 102−104 for the other decays, relative to the Standard Model. We subsequently determine the preferred parameter space regions of the model in terms of potential of being reached in the near future

Quantitative CT Imaging of Ventral Hernias: Preliminary Validation of an Anatomical Labeling Protocol

<div><p>Objective</p><p>We described and validated a quantitative anatomical labeling protocol for extracting clinically relevant quantitative parameters for ventral hernias (VH) from routine computed tomography (CT) scans. This information was then used to predict the need for mesh bridge closure during ventral hernia repair (VHR).</p><p>Methods</p><p>A detailed anatomical labeling protocol was proposed to enable quantitative description of VH including shape, location, and surrounding environment (61 scans). Intra- and inter-rater reproducibilities were calculated for labeling on 18 and 10 clinically acquired CT scans, respectively. Preliminary clinical validation was performed by correlating 20 quantitative parameters derived from anatomical labeling with the requirement for mesh bridge closure at surgery (26 scans). Prediction of this clinical endpoint was compared with similar models fit on metrics from the semi-quantitative European Hernia Society Classification for Ventral Hernia (EHSCVH).</p><p>Results</p><p>High labeling reproducibilities were achieved for abdominal walls (±2 mm in mean surface distance), key anatomical landmarks (±5 mm in point distance), and hernia volumes (0.8 in Cohen’s kappa). 9 out of 20 individual quantitative parameters of hernia properties were significantly different between patients who required mesh bridge closure versus those in whom fascial closure was achieved at the time of VHR (p<0.05). Regression models constructed by two to five metrics presented a prediction with 84.6% accuracy for bridge requirement with cross-validation; similar models constructed by EHSCVH variables yielded 76.9% accuracy.</p><p>Significance</p><p>Reproducibility was acceptable for this first formal presentation of a quantitative image labeling protocol for VH on abdominal CT. Labeling-derived metrics presented better prediction of the need for mesh bridge closure than the EHSCVH metrics. This effort is intended as the foundation for future outcomes studies attempting to optimize choice of surgical technique across different anatomical types of VH.</p></div

Results of preliminary statistical analyses.

<p>(a) and (b) shows the number of false predictions and number of included variables over different alpha values using cross-validated elastic net regularized logistic regression, respectively. Generally, a larger alpha value yields stronger regularization, and thus involves less variables for the regression model. Note that the blue dashed curves represent the regression results using EHSCHV variables, while the green solid curves use the variables derived from labeling. (c) presents a hyper-plane using support vector machine to separate the two groups of patients with distinct technical outcomes by the two remaining labeling-derived variables of an exploratory regression model built upon all observations.</p

Overview of the anatomical labeling protocol.

<p>(a) Axial and sagittal slices to label are determined in terms of the size and resolution of the volume. (b) On the selected axial slices, the anterior (outer and inner borders) and posterior abdominal wall is traced. At the same time, linea alba and linea semilunaris are labeled on the appropriate axial slices. (c) The VH is labeled entirely on every axial slice where the hernia exists. (d) On the selected sagittal slices, the outer and inner borders of the anterior abdominal wall are traced. Note the previous VH and abdominal wall labels can be helpful references. (e) The umbilicus and skeletal landmarks are labeled. (f) The complete set of labels is reviewed.</p

Statistical comparison of 20 metrics between two groups of patients with distinct outcomes.

<p>^a Each index refers to a metric in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0141671#pone.0141671.t002" target="_blank">Table 2</a></p><p>* indicates significant difference between the two groups</p><p>Statistical comparison of 20 metrics between two groups of patients with distinct outcomes.</p

Hernia volume reliability.

<p>Hernia volume reliability.</p