What Mesh Should be Used in Hernia Repair?

Ventral hernia repair is one of the most frequently performed general surgery operations in the world, yet the treatment of clean-contaminated and contaminated cases remains controversial. Biologic mesh has been thought to resist infection, decrease chronic wound complications, and reduce the need for reoperation. Their use continues to be predominant in contaminated and dirty cases. This article is a comprehensive review of what mesh to choose in both clean and contaminated single-staged, open ventral hernia repair with further considerations of tissue incorporation characteristics, cost, safety profiles, complications, recurrence, and long-term outcomes.

Seasonal assessment of the distribution, source apportionment, and risk of water-contaminated polycyclic aromatic hydrocarbons (PAHs)

The research aims to evaluate the seasonal differences in the distribution, source, and risks of water-contaminated PAHs. The PAHs were extracted by the liquid-liquid method and analyzed with GC-MS, and a total of eight PAHs were detected. There was a percentage increase in the average concentration of the PAHs from the wet to the dry season in the range of 20 (Anthracene)-350 (Pyrene)%. Total PAHs (∑PAHs) range from 0.31 to 1.23 mg/l in the wet period and from 0.42 to 1.96 mg/l in the dry period. The distribution of the average PAHs in mg/l showed that Fluoranthene ≤ Pyrene < Acenaphthene < Fluorene < Phenanthrene < Acenaphthylene < Anthracene < Naphthalene in wet period and while Fluoranthene < Acenaphthene < Pyrene < Fluorene < Phenanthrene < Acenaphthylene < Anthracene < Naphthalene in the dry period. The children were exposed to non-carcinogenic risk through non-dietary ingestion due to the accumulative effect (HI) of the PAHs in the dry period. Furthermore, the naphthalene was responsible for ecological and carcinogenic risk in the wet period, while the fluorene, phenanthrene, and anthracene were responsible for ecological and carcinogenic risk in the dry period. However, while adults and children are both susceptible to carcinogenic risk through the oral channel during the dry period, only children are susceptible to non-carcinogenic risk through this pathway. The multivariate statistical analysis revealed the influence of physicochemical parameters on the detected PAHs and also showed the PAHs' sources to be mainly combustion, pyrolysis, and vehicular emission.

Biosynthetic meshes in contaminated fields: where are we now? A systematic review and meta-analysis in humans

PURPOSE

Selection of an appropriate mesh reinforcement for hernia repair in contaminated fields is a significant problem for surgeons. To date the proper mesh for contaminated fields has not been found. Biosynthetic meshes have emerged as new treatment option in contaminated fields. This study aims to evaluate the postoperative outcomes of biosynthetic meshes in contaminated fields.

METHODS

Systematic electronic search (PubMed, Medline, Embase, Scopus), according to PRISMA criteria, was performed. A literature search of scientific papers was performed by two reviewers until April 2021. Articles were chosen based on reference to biosynthetic meshes, their use in infected fields, and in human subjects. GRADE methodology and the modified Newcastle-Ottawa scale were used to assess the quality of studies. According to CDC-Centers for Disease Control classes patients were divided into two subgroups, group 1 (CDC class 2) and group 2 (CDC classes 3-4).

RESULTS

The research included 21 articles and 1619 patients were analyzed. Long-term follow-up showed a significant higher recurrence rate than short-term follow-up. P < 0.001. Meta-analysis of these studies showed that the SSI were significantly higher in CDC classes 3-4 than CDC class 2 (P < 0.01). No differences were found in SSO (P = 0.06) and recurrence (P = 0.37) rate among the two groups. Phasix™ was the most common mesh in 15 studies. The mean follow-up was 23.0 months. The surgical site infection (SSI) rate was 17.3%. The surgical site occurrence (SSO) rate was 32.4%. Recurrence rate was 11.5%.

CONCLUSION

This is the first systematic review and meta-analysis on the clinical outcomes of abdominal wall repair using biosynthetic mesh in contaminated-infected settings. The results show good results in patients at high risk of postoperative wound complications. The aim of this study is to add to the growing literature on biosynthetic mesh a picture of current literature evidence to help future researchers performing further studies on this topic.

Outcomes of biologic versus synthetic mesh in CDC class 3 and 4 open abdominal wall reconstruction

INTRODUCTION

Abdominal wall reconstruction (AWR) in a contaminated field is associated with an increased risk of wound complications, infection, and reoperation. The best method of repair and mesh choice in these operations have generated marked controversy. Our aim was to compare outcomes of patients who underwent AWR with biologic versus synthetic mesh in CDC class 3 and 4 wounds.

METHODS

A prospective, single-institution database was queried for AWR using biologic or synthetic mesh in CDC Class 3 and 4 wounds. Hernia recurrence and complications were measured. Multivariable logistic regression was performed to identify factors predicting both.

RESULTS

In total, 386 patients with contaminated wounds underwent AWR, 335 with biologic and 51 with synthetic mesh. Groups were similar in age, sex, BMI, and rate of diabetes. Biologic mesh patients had larger hernia defects (298 ± 233cm² vs. 208 ± 155cm²; p = 0.004) and a higher rate of recurrent hernias (72.2% vs 47.1%; p < 0.001), comorbidities(5.8 ± 2.7 vs. 4.2 ± 2.4, p < 0.01), and a nearly fivefold increase in Class 4 wounds (47.8% vs. 9.8%, p < 0.001), while fascial closure trended to being less common (90.7% vs 96.1%; p = 0.078). Hernia recurrence was comparable between biologic and synthetic mesh (10.4% vs. 17.6%, p = 0.132). Wound complication rates were similar (36.1% vs. 33.3%, p = 0.699), but synthetic mesh had higher rates of mesh infection (1.2% vs 11.8%; p < 0.001) and infection-related resection (0% vs 7.8%, p < 0.001), with 66% of those synthetic mesh infections requiring excision. On logistic regression, wound complications (OR 5.96 [CI 1.60-22.17]; p = 0.008) and bridging mesh (OR 13.10 [CI 2.71-63.42];p = 0.030) predicted of hernia recurrence (p < 0.05), while synthetic mesh (OR 18.6 [CI 2.35-260.4] p = 0.012) and wound complications (OR 20.6 [CI 3.15-417.7] p = 0.008) predicted mesh infection.

CONCLUSIONS

Wound complications in AWR with CDC class 3 and 4 wounds significantly increased mesh infection and hernia recurrence; failure to achieve fascial closure also increased hernia recurrence. Use of synthetic versus biologic mesh increased the mesh infection rate by 18.6 times.

Delayed primary closure (DPC) of the skin and subcutaneous tissues following complex, contaminated abdominal wall reconstruction (AWR): a propensity-matched study

BACKGROUND

Wound complications following abdominal wall reconstruction (AWR) in a contaminated setting are common and significantly increase the risk of hernia recurrence. The purpose of this study was to examine the effect of short-term negative pressure wound therapy (NPWT) followed by operative delayed primary closure (DPC) of the skin and subcutaneous tissue after AWR in a contaminated setting.

METHODS

A prospective institutional hernia database was queried for patients who underwent NPWT-assisted DPC after contaminated AWR between 2008 and 2020. Primary outcomes included wound complication rate and reopening of the incision. A non-DPC group was created using propensity-matching. Standard descriptive statistics were used, and a univariate analysis was performed between the DPC and non-DPC groups.

RESULTS

In total, 110 patients underwent DPC following AWR. The hernias were on average large (188 ± 133.6 cm²), often recurrent (81.5%), and 60.5% required a components separation. All patients had CDC Class 3 (14.5%) or 4 (85.5%) wounds and biologic mesh placed. Using CeDAR, the wound complication rate was estimated to be 66.3%. Postoperatively, 26.4% patients developed a wound complication, but only 5.5% patients required reopening of the wound. The rate of recurrence was 5.5% with mean follow-up of 22.6 ± 27.1 months. After propensity-matching, there were 73 patients each in the DPC and non-DPC groups. DPC patients had fewer overall wound complications (23.0% vs 43.9%, p = 0.02). While 4.1% of the DPC group required reopening of the incision, 20.5% of patients in the non-DPC required reopening of the incision (p = 0.005) with an average time to healing of 150 days. Hernia recurrence remained low overall (2.7% vs 5.4%, p = 0.17).

CONCLUSIONS

DPC can be performed with a high rate of success in complex, contaminated AWR patients by reducing the rate of wound complications and avoiding prolonged healing times. In patients undergoing AWR in a contaminated setting, a NPWT-assisted DPC should be considered.

Ventral hernia repair with synthetic mesh in a contaminated field: a systematic review and meta-analysis

PURPOSE

The use of mesh in ventral hernia repair becomes especially challenging when associated with a contaminated field. Permanent synthetic mesh use in this setting is currently debated and this discussion is yet to be resolved clinically or in the literature. We aim to systematically assess postoperative outcomes of non-absorbable synthetic mesh (NASM) used in ventral hernia repair in the setting of contamination.

METHODS

A literature search of PubMed, Embase, Scopus, Cinahl, and Cochrane Library identified all articles from 2000-2020 that examined the use of NASM for ventral hernia repair in a contaminated field. Postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Qualitative analysis was completed for all included studies using a modified Newcastle-Ottawa scale.

RESULTS

Of 630 distinct publications and 104 requiring full review, this study included 17 articles published between 2007 and 2020. Meta-analysis demonstrated absorbable mesh was associated with more HR (OR 1.89, 1.15-3.12, p = 0.008), SSO (OR 1.43, 0.96-2.11, p = 0.087), SSI (OR 2.84, 1.85-4.35, p < 0.001), and unplanned reoperation (OR 1.99, 1.19-3.32, p = 0.009) compared to NASM.

CONCLUSION

The use of NASM for ventral hernia repair in a contaminated field may be a safe alternative to absorbable mesh, as evidenced by lower rates of postoperative complications. This review counters the current clinical paradigm, and additional prospective randomized controlled trials are warranted.

A focused netnographic study exploring experiences associated with counterfeit and contaminated anabolic-androgenic steroids

Background

A primary consequence of illicit drug markets and the absence of regulation is the variable quality or purity of the final product. Analysis of anabolic-androgenic steroid seizures shows that these products can contain adulterated products, product not included on the label, or product of unsatisfactory standard. While the potential negative effects of counterfeit anabolic-androgenic steroids (AAS) use is a recognised risk associated with use, no study has explored personal experiences associated with use. The aim of the present study was to use online discussion forums to investigate and explore the experiences associated with the purchase and consumption of counterfeit AAS among consumers.

Methods

An online search was conducted to identify online forums that discussed counterfeit or contaminated AAS; three were deemed suitable for the study. The primary source of data for this study was the ‘threads’ from these online forums, identified using search terms including ‘counterfeit’, ‘tampered’, and ‘fake’. Threads were thematically analysed for overall content, leading to the identification of themes.

Results

Data from 134 threads (2743 posts from 875 unique avatars) was included. Two main themes were identified from the analysis: (1) experiences with counterfeit product and (2) harms and benefits associated with counterfeit product.

Conclusions

The use of counterfeit or contaminated substances represents a public health concern. Those who report using performance and image enhancing drugs such as AAS for non-medical purposes report consuming these substances and experiencing harm as a result. Consumers take steps to limit coming into contact with counterfeit or contaminated product, though recognise that many of these have limitations. The implementation of accessible drug safety checking services may provide an opportunity to provide consumers with information to assist them with making healthier choices.

The development and validation of risk-stratification models for short-term outcomes following contaminated complex abdominal wall reconstruction

BACKGROUND

Short-term outcomes for patients undergoing contaminated complex abdominal wall reconstruction (CCAWR), including risk stratification, have not been studied in sufficiently high numbers. This study aims to develop and validate risk-stratification models for Clavien-Dindo (CD) grade ≥ 3 complications in patients undergoing CCAWR.

METHODS

A consecutive cohort of patients who underwent CCAWR in two European national intestinal failure centers, from January 2004 to December 2015, was identified. Data were collected retrospectively for short-term outcomes and used to develop risk models using logistic regression. A further cohort, from January 2016 to December 2017, was used to validate the models.

RESULTS

The development cohort consisted of 272 procedures performed in 254 patients. The validation cohort consisted of 114 patients. The cohorts were comparable in baseline demographics (mean age 58.0 vs 58.1; sex 58.8% male vs 54.4%, respectively). A multi-variate model including the presence of intestinal failure (p < 0.01) and operative time (p < 0.01) demonstrated good discrimination and calibration on validation. Models for wound and intra-abdominal complications were also developed, including pre-operative immunosuppression (p = 0.05), intestinal failure (p = 0.02), increasing operative time (p = 0.04), increasing number of anastomoses (p = 0.01) and the number of previous abdominal operations (p = 0.02). While these models showed reasonable ability to discriminate patients on internal assessment, they were not found to be accurate on external validation.

CONCLUSION

Acceptable short-term outcomes after CCAWR are demonstrated. A robust model for the prediction of CD ≥ grade 3 complications has been developed and validated. This model is available online at www.smbari.co.uk/smjconv2.

Strategic considerations for the sustainable remediation of nuclear installations

Nuclear sites around the world are being decommissioned and remedial actions are being undertaken to enable the sites or parts of the sites to be reused. Although this is relatively straightforward for most sites, experience has suggested that preventative action is needed to minimise the impact of remediation activities on the environment and the potential burden to future generations. Removing all contamination in order to make a site suitable for any use generates waste and has associated environmental, social and economic detriments and benefits that should be taken into account. Recent experience of OECD Nuclear Energy Agency (NEA) member countries in the remediation of contaminated land, predominantly contaminated soil and groundwater, on nuclear sites during decommissioning has been assessed by an NEA task group. The experience was used to identify strategic considerations for nuclear site remediation, to consider the application of sustainability principles to nuclear site remediation, to describe good practice, and to make recommendations for further research and development. The key aspects that were identified were that 1) site remediation should be sustainable by resulting in an overall net benefit; and 2) an adaptive approach is essential in order to take into account the inherent uncertainty associated with the decommissioning and site remediation timescales. A report describing the findings was published by OECD/NEA in 2016. The conclusions provide insights to decision makers, regulators, implementers and stakeholders involved in nuclear site decommissioning so that they can achieve sustainable remediation of nuclear sites, now and in the future.

Biochar application for the remediation of heavy metal polluted land: A review of in situ field trials

Polluted land is a global issue, especially for developing countries. It has been reported that soil amendment with biochar may reduce the bioavailability of a wide range of contaminants, including heavy metal(loids), potentially reclaiming contaminated soils for agricultural use. However, there have been only limited reports on the in situ application of biochar at the field scale. This review was devoted to providing preliminary scientific evidence from these field trials, based on a review of 29 publications involving field applications of biochar in 8 different countries. The data show that biochar's effectiveness in reducing the impacts of pollution depends on a myriad of factors in the field, including the application time period, site-specific factors (e.g. climate, biochar dosage rate, and mixing depth), biochar feedstock type, and biochar properties. The results of this review indicate that biochar application can potentially reduce contaminant bioavailability in the field; for instance, a significant decrease (control normalized mean value=0.55) in the Cd enrichment of rice crops was observed. It was found that the use of biochar may help increase crop yields on polluted land, and thus reduce the amount of mineral fertilizer used in the field. However, in order to maximize the benefits of biochar addition, farmers need to accept that the dosage rates of mineral fertilizers should be reduced. This review also revealed that the effectiveness of biochar in mitigating pollution may decrease with time due to ageing factors, such as leaching of biochar alkalinity.

Biogeochemical controls on methylmercury in soils and sediments: Implications for site management

Management of Hg-contaminated sites poses particular challenges because methylmercury (MeHg), a potent bio-accumulative neurotoxin, is formed in the environment, and concentrations are not generally predictable based solely on total Hg (THg) concentrations. In this review, we examine the state of knowledge regarding the chemical, biological, and physical controls on MeHg production and identify those most critical for contaminated site assessment and management. We provide a list of parameters to assess Hg-contaminated soils and sediments with regard to their potential to be a source of MeHg to biota and therefore a risk to humans and ecological receptors. Because some measurable geochemical parameters (e.g., DOC) can have opposing effects on Hg methylation, we recommend focusing first on factors that describe the potential for Hg bio-accumulation: site characteristics, Hg and MeHg concentrations, Hg availability, and microbial activity, where practical. At some sites, more detailed assessment of biogeochemistry may be required to develop a conceptual site model for remedial decision making. Integr Environ Assess Manag 2017;13:249-263. © 2016 SETAC.

Evaluation of antibiotic pressurized pulse lavage for contaminated retromuscular abdominal wall reconstruction

BACKGROUND

Despite patient risk factors such as diabetes and obesity, contamination during surgery remains a significant cause of infections and subsequent wound morbidity. Pressurized pulse lavage (PPL) has been utilized as a method to reduce bacterial bioburden with promising results in many fields. Although existing methods of lavage have been utilized during abdominal operations, no studies have examined the use of PPL during complex hernia repair.

METHODS

Patients undergoing abdominal wall reconstruction (AWR) in clean-contaminated or contaminated fields with antibiotic PPL, from January 2012 to May 2013, were prospectively evaluated. Primary outcome measures studied were conversion of retrorectus space culture from positive to negative after PPL and 30-day surgical site infection (SSI) rate.

RESULTS

A total of 56 patients underwent AWR, with 44 patients (78.6 %) having clean-contaminated fields and 12 patients (21.4 %) having contaminated ones. Twenty-two patients (39.3 %) had positive pre-PPL cultures, 18 of which (81.8 %) converted to negative cultures after PPL. Eleven patients (19.6 %) developed SSIs. Those with persistently positive cultures after PPL had the highest rate of SSI, where two out of four patients (50.0 %) developed an SSI. Contrastingly, only 5 of 18 patients (27.8 %) who converted from a positive to negative culture after PPL developed an SSI.

CONCLUSION

Our findings demonstrate that antibiotic PPL is an effective method to reduce bacterial bioburden during AWR in clean-contaminated and contaminated fields. While complete conversion and eradication of SSI were not achieved, we believe that PPL may be a useful adjunct to standard operative asepsis in preventing prosthetic contamination during contaminated AWR.

Contaminated wounds: Effectiveness of debridement for reducing bacterial load

Surgical management of contaminated hand wounds may seem anecdotal, but such injuries actually account for an appreciable amount of the activity in emergency hand centers, and recommendations put forward by scientific societies differ. Dealing effectively with this public health issue calls for clarifying the usefulness of the various available treatments. Our study's objective was to determine the effectiveness of surgical debridement. In this prospective study, 92 patients with contaminated hand wounds underwent surgical debridement. Selection criteria included the length of time between injury and treatment, and the mechanism of injury. Patients with infected wounds, those treated by antibiotics, who were immunosuppressed or had osteoarthritis were excluded. Skin samples were collected both before and after debridement. In 62% of cases, the wounds were contaminated before debridement. Following the procedure, 87% of the bacterial smears were negative. The comparison between debridement and smear results was statistically significant (Student's t test, P<0.001). Surgical debridement, with appropriate irrigation, can effectively eradicate bacterial flora due to contamination.

APIC position paper: Safe injection, infusion, and medication vial practices in health care

The transmission of bloodborne viruses and other microbial pathogens to patients during routine health care procedures continues to occur because of the use of improper injection, infusion, medication vial, and point-of-care testing practices by health care personnel. These unsafe practices occur in various clinical settings and result in unacceptable and devastating events for patients. This document updates the Association for Professionals in Infection Control and Epidemiology 2010 position paper on safe injection, infusion, and medication vial practices in health care.

A dual-stage approach to contaminated, high-risk ventral hernia repairs

BACKGROUND

The Modified Hernia Grading System (MHGS) was developed to risk stratify complex ventral hernia repairs (VHRs). MHGS grade 3 patients have mesh infections, dirty or contaminated fields, and/or violation of the alimentary tract. Reported surgical site infection (SSI) rates are over 40% after single-stage VHR in contaminated fields. In an attempt to decrease the SSI rate in MHGS grade 3 patients, we developed a dual-stage VHR (DSVHR) approach.

METHODS

We reviewed adult general surgery patients undergoing DSVHR between January 2010 and June 2014. All patients were MHGS grade 3. Primary end point was 30-d superficial and deep SSI. Secondary end points included other surgical site occurrences, 6-mo recurrence, and mesh excision rates.

RESULTS

Fifteen patients underwent DSVHR. Mean age was 56 y, and median body mass index was 38.3 kg/m(2). Operative indication included enterocutaneous fistulas (ECF; n = 6), ECF with infected mesh (n = 2), infected mesh (n = 2), and VHR requiring bowel resection (n = 5). Thirty-one operative procedures were performed with median of 2.5 d between procedures. Fascial closure was re-established in 12 patients; five patients had underlay biologic mesh placement; seven underwent component separation with retrorectus mesh placement (synthetic [n = 2], biologic [n = 5]). The remaining patients underwent bridging repair with biologic mesh. One patient developed a recurrence after 6 mo, whereas a single patient had a recurrence of their ECF. Four (27%) patients developed a SSI, with an additional four (27%) experiencing a surgical site occurrence. There were no postoperative mesh infections.

CONCLUSIONS

DSVHR in MHGS grade 3 patients is associated with a lower SSI rate than previously reported for those undergoing single-stage repairs.

Suture, synthetic, or biologic in contaminated ventral hernia repair

BACKGROUND

Data are lacking to support the choice between suture, synthetic mesh, or biologic matrix in contaminated ventral hernia repair (VHR). We hypothesize that in contaminated VHR, suture repair is associated with the lowest rate of surgical site infection (SSI).

METHODS

A multicenter database of all open VHR performed at from 2010-2011 was reviewed. All patients with follow-up of 1 mo and longer were included. The primary outcome was SSI as defined by the Centers for Disease Control and Prevention. The secondary outcome was hernia recurrence (assessed clinically or radiographically). Multivariate analysis (stepwise regression for SSI and Cox proportional hazard model for recurrence) was performed.

RESULTS

A total of 761 VHR were reviewed for a median (range) follow-up of 15 (1-50) mo: there were 291(38%) suture, 303 (40%) low-density and/or mid-density synthetic mesh, and 167(22%) biologic matrix repair. On univariate analysis, there were differences in the three groups including ethnicity, ASA, body mass index, institution, diabetes, primary versus incisional hernia, wound class, hernia size, prior VHR, fascial release, skin flaps, and acute repair. The unadjusted outcomes for SSI (15.1%; 17.8%; 21.0%; P = 0.280) and recurrence (17.8%; 13.5%; 21.5%; P = 0.074) were not statistically different between groups. On multivariate analysis, biologic matrix was associated with a nonsignificant reduction in both SSI and recurrences, whereas synthetic mesh associated with fewer recurrences compared to suture (hazard ratio = 0.60; P = 0.015) and nonsignificant increase in SSI.

CONCLUSIONS

Interval estimates favored biologic matrix repair in contaminated VHR; however, these results were not statistically significant. In the absence of higher level evidence, surgeons should carefully balance risk, cost, and benefits in managing contaminated ventral hernia repair.

Contaminated osteochondral plugs: effect of different sterilizing solutions: an experimental study in the rabbit

BACKGROUND

To determine the efficacy of different antiseptic solutions (Control group (I), Antibiotic solution (II), Chlorhexidine 0.4% (III), and povidone - iodine 10% (IV)) in sterilizing contaminated osteochondral plugs.

METHODS

Under sterile conditions, the femoral head and condyles of 20 rabbits were removed and cut into equal osteochondral pieces. A total of 200 osteochondral specimens were obtained. All 200 specimens were dropped on the operating room floor for fifteen seconds and assigned to one of four experimental groups. Group I samples were cultured after washing with normal saline solution (Control group). In other three groups, prior to culturing process, samples were placed in an antibiotic solution after washing with normal saline (Neomycin & Polymyxin) (group II), Chlorhexidine 0.4% (group III), and povidone - iodine 10% (group IV), respectively.

RESULTS

In group I, 25 of 50 specimens had positive cultures. Of 50 specimens of group II, III and IV, no positive cultures were found after 10 days.

CONCLUSION

All three agents including antibiotic solution, povidone-iodine 10% and chlorhexidine 0.4% seem effective in sterilizing the contaminated osteochondral samples. According to the literature, povidone-iodine has no negative effect on the cartilage metabolism and seems to be a proper choice of decontaminating solution for osteochondral plugs.To the best of the authors' knowledge, such a study on the contaminated osteochondral specimen has not been previously reported in the literature.