Shape-Configurable Mesh for Hernia Repair by Synchronizing Anisotropic Body Motion.

Continuous progress has been made in elucidating the relationship between material property, device design, and body function to develop surgical meshes. However, an unmet need still exists wherein the surgical mesh can handle the body motion and thereby promote the repair process. Here, the hernia mesh design and the advanced polymer properties are tailored to synchronize with the anisotropic abdominal motion through shape configuration. The thermomechanical property of shape configurable polymer enables molding of mesh shape to fit onto the abdominal structure upon temperature shift, followed by shape fixing with the release of the heat energy. The microstructural design of mesh is produced through finite element modeling to handle the abdominal motion efficiently through the anisotropic longitudinal and transverse directions. The design effects are validated through in vitro, ex vivo, and in vivo mechanical analyses using a self-configurable, body motion responsive (BMR) mesh. The regenerative function of BMR mesh leads to effective repair in a rat hernioplasty model by effectively handling the anisotropic abdomen motion. Subsequently, the device-tissue integration is promoted by promoting healthy collagen synthesis with fibroblast-to-myofibroblast differentiation. This study suggests a potential solution to promote hernia repair by fine-tuning the relationship between material property and mesh design.

[Safety of mesh with fluoropolymer coating during intra-abdominal placement in large animals: results of the pilot study]. / Bezopasnost' setchatykh endoprotezov s ftorpolimernym pokrytiem: rezul'taty pilotnogo issledovaniya.

OBJECTIVE: When performing laparoscopic intraperitoneal hernioplasty (IPOM), endoprostheses made of fluoropolymers are often used. However, there is no data in the literature on the intra-abdominal use of inexpensive polyester prostheses with a fluoropolymer coating compared to composite implants. Thus, the aim of the pilot study was a preliminary assessment of the safety profile of FTOREX mesh endoprostheses during intra-abdominal placement in large animals. MATERIAL AND METHODS: 6 endoprostheses were installed laparoscopically intraperitoneally in each of the 3 pigs: 1) FTOREX; 2) FTOREX with a layer of carboxymethylcellulose; 3) REPEREN-16-2; 4) SYMBOTEX; 5) VENTRALIGHT ST; 6) decellularized pork peritoneum. Fixation was performed with a herniator, transfascial sutures were not used. Relaparoscopy was performed after 45 days, and withdrawal from the experiment was performed after 90 days. Performance characteristics, signs of deformation and retraction, parameters of spike formation were evaluated. RESULTS: All the animals survived, no complications were observed. There were no clinical manifestations or behavioral reactions indicating the presence of adhesions. The most convenient to use were the SYMBOTEX and FTOREX implants (5.0 points each). By the end of the experiment, deformation and retraction were noted in both variants of the FTOREX implants and the REPEREN prosthesis. These changes were completely absent only when using the SYMBOTEX endoprosthesis. According to the number of implants with adhesions, by the end of the observation, both variants of FTOREX prostheses occupied an intermediate position between the Reference (the worst indicator) and VENTRALIGHT ST (the best indicator). However, both FTOREX endoprostheses showed the best performance among all implants in the integral assessment of adhesions, as well as in terms of parameters such as the area and appearance of adhesions, and in terms of the strength of the joints, they were second only to the VENTRALIGHT ST endoprosthesis (0.67 vs. 0.5 points). During the study, there was no reliable dependence of deformation, retraction and adhesion formation indicators on the type of implant. CONCLUSION: The results of the pilot study showed that all the implants used did not cause any clinically significant adverse reactions or complications. FTOREX endoprostheses with their intraperitoneal installation have anti-adhesive properties that are not inferior to VENTRALIGHT ST or SYMBOTEX composite implants. However, having less rigidity, they are more often deformed and subjected to retraction.

[Histological changes in intraperitoneal onlay mesh (IPOM) with synthetic and biological meshes. Results of the chronic experiment]. / Gistologicheskie izmeneniya pri intraperitoneal'noi plastike (IPOM) sinteticheskimi i biologicheskimi endoprotezami. Rezul'taty khronicheskogo eksperimenta.

OBJECTIVE: The objective of the study was to analyze histological changes in the site of the meshes FTOREX, FTOREX coated with carboxymethylcellulose, Ventralight ST, Symbotex, REPEREN-16-2 and decellularized porcine peritoneum on the parietal peritoneum of the pig. MATERIAL AND METHODS: At laparoscopy, 6 different meshes were placed intraperitoneally in each of the 3 pigs. After 90 days, the animals were taken out of the experiment. After staining with hematoxylin and eosin, quantitative morphometry and counting the number of vessels and cells in the interstitium in the areas of the mesh and peritoneum were performed. An immunohistochemical study with an antibody to pancytokeratins assessed the state of the initial peritoneum and neoperitoneum. RESULTS: According to morphological characteristics, the meshes were divided into 3 groups: 1) with fluoropolymer coating FTOREX, 2) Ventralight ST and Symbotex, 3) REPEREN and decellularized peritoneum. In group 1, the surface area of the mesh threads was optimal in terms of the arrangement and arrangement of the threads relative to each other. This contributed to the formation of a relatively dense fibrous framework and a place to preserve the underlying peritoneum involved in the formation of the neoperitoneum. Despite the smallest surface area of the threads, in group 3, the greatest fibroblastic reaction was noted. Inflammatory changes were the least pronounced in group 1. They were the greatest in group 3, where there was a pronounced leukocyte reaction, combined with the processes of metaplasia, the development of fibrinoid necrosis, and the progression of the secondary inflammatory process. In group 1, the optimal ratio of newly formed vessels was noted, in group 2 - veins prevailed over arteries, in group 3 - the number of vessels was minimal. Immunohistochemical study showed that in group 1, mesothelial cells covered almost the entire surface of the implant, and there were also areas of preserved basic peritoneum. In group 2, mesothelium also covered most of the surface of the meshes, but the underlying peritoneum was absent. In group 3, on the contrary, a significant number of extended areas not covered with mesothelium were revealed. CONCLUSION: The conducted morphological and morphometric study showed that the most balanced ratio of the components of the newly formed fibrous tissue and blood vessels is observed when using implants with a fluoropolymer coating FTOREX. At the same time, the remaining basic peritoneum actively participated in the formation of the neoperitoneum. The Ventralight ST and Symbotex meshes also contributed to the formation of a full-fledged fibrous tissue and adequate vascular proliferation, however, they prevented the preservation of the underlying peritoneum, which practically excluded its participation in the formation of the neoperitoneum. The REPEREN mesh and decellularized porcine peritoneum led to the least balanced cell and vascular proliferation and the greatest fibroplastic reaction, which could further negatively affect the state of the formed scar.

Prophylactic Effect of Simultaneous Placement of Mesh on Incidence of Parastomal Hernia After Miles' Surgical Resection of Colorectal Cancer: A Prospective Study.

INTRODUCTION: To assess the prophylactic effect of simultaneous placement of mesh and the incidence of parastomal hernia (PSH) after abdominoperineal resection of rectal cancer. METHODS: This study included real-world data of 56 surgically resected patients with colorectal cancer who were consecutively assigned to two groups: control (no mesh, n = 32) and experimental (received mesh, n = 24). An artificial patch was placed under the tunica vaginalis of rectus abdominis for patients in the experimental group, whereas those in the control group received routine sigmoidostomy. The median follow-up time was >20 mo. The difference in hazards function was analyzed by cox regression analysis. The Kaplan-Meir analysis was used to determine the survival curves. A P value of <0.05 was considered as significant. RESULTS: The postoperative incidence rate of PSH was lower in the experimental (41.7%) group than in the control group (71.9%; P = 0.045). The PSH postoperative time in the experimental group was significantly delayed compared to the control group (48 mo versus 10 mo; P < 0.001). The risk of progression from H1 to H2 was less in the experimental group compared to the control group (49.28% versus 60.86%; P = 0.14). CONCLUSIONS: Prophylactic mesh placement significantly prolonged postoperative time for the recurrence of PSH. The incidence of recurrence of H2 (severe PSH) requiring secondary surgical repair was also reduced.

Emergent and urgent ventral hernia repair: comparing recurrence rates amongst procedures utilizing mesh versus no mesh.

BACKGROUND: The decision for emergent and urgent ventral hernia repair (VHR) is driven by acute symptomatology, concern for incarceration and strangulation, and perforation. Although mesh has been established to reduce hernia recurrences, the potential for mesh complications may impact the decision for utilization in emergent repairs. This study evaluates hernia repair outcomes in the emergent setting with/without mesh. METHODS: An IRB-approved review of NSQIP and retrospective chart review data of emergent/urgent VHRs performed between 2013 and 2017 was conducted at a single academic institution. Six-month postoperative emergency department and surgery clinic visits, hospital readmissions, and hernia recurrences were recorded. Patients were grouped based on mesh utilization. Perioperative and outcome variables were compared using Chi-square, Fisher's exact, and t-tests. RESULTS: Among 94 patients, 41 (44%) received mesh; 53 (56%) did not. Synthetic mesh was used in 27 cases (65.9%); bioresorbable or biologic mesh was used in 14 cases (34.1%). ASA class (p = 0.016) was higher in the no-mesh group, as were emergent vs. urgent cases (p ≤ 0.001). Preoperative SIRS/Sepsis, COPD, and diabetes were increased in the no-mesh group. Hernia recurrence was significantly higher in the no-mesh group vs. the mesh group (24.5% vs. 7.3%, p = 0.03). No difference was found in wound complications between groups. ED visits occurred almost twice as often in the mesh group (42% vs. 23%, p = 0.071). Postoperative surgery clinic visits were more frequent among the mesh group (> 1 visit 61% vs. 24%, p = 0.004). CONCLUSIONS: Mesh-based hernia repairs in the urgent/emergent patient population are performed in fewer than half of patients in our tertiary care referral center. Repairs without mesh were associated with over a three-fold increase in recurrence without a difference in the risk of infectious complications. Efforts to understand the rationale for suture-based repair compared to mesh repair are needed to reduce hernia recurrences in the emergent population.

Inguinal hernia mesh is safe in 1720 patients.

BACKGROUND: There is substantial media and patient interest in the safety of mesh for hernia repair. However, there is a lack of data regarding health-related quality of life (HRQOL) outcomes in patients who undergo inguinal hernia repair (IHR) with mesh. The purpose of this study is report short and long-term postoperative quality of life outcomes in patients following IHR with mesh. METHODS: We analyzed outcomes of 1720 patients who underwent IHR with mesh between 2008 and 2019 at a single institution from a prospectively maintained quality database. All surgeries were performed by four board-certified surgeons. HRQOL outcomes were measured using the Surgical Outcomes Measurement System (SOMS) and Carolinas Comfort Scale (CCS) surveys that were administered preoperatively, 3 weeks, 6 months, 1, 2, and 5 years postoperatively. Survey responses were summarized as mean with standard deviation or frequency with percentage. Postoperative SOMS scores were compared to preoperative scores using the two-tailed paired t test with a significance level of p < 0.05. RESULTS: One (0.1%) patient experienced a mesh infection postoperatively. In terms of complications, 159 (9.2%) developed a seroma, 31 (1.8%) a hematoma, and 36 (2.1%) patients experienced a recurrence. SOMS Pain Impact, SOMS Pain Quality, and SOMS Pain visual analog scale at 3 weeks, 6 months, 1 year, 2 years, and 5 years were all improved from preoperative (all p < 0.05). At 5 years postoperatively, only 3.9%, 3.2%, and 3.1% of patients reported severe or disabling sensation of mesh, pain, and movement limitations, respectively. CONCLUSION: Inguinal hernia repair with mesh results in a low rate of complications. A minority of patients had severe or disabling symptoms at 5-year follow-up and generally reported improvements in pain impact and quality in long-term follow-up.

In Vitro Cytotoxicity, Colonisation by Fibroblasts and Antimicrobial Properties of Surgical Meshes Coated with Bacterial Cellulose.

Hernia repairs are the most common abdominal wall elective procedures performed by general surgeons. Hernia-related postoperative infective complications occur with 10% frequency. To counteract the risk of infection emergence, the development of effective, biocompatible and antimicrobial mesh adjuvants is required. Therefore, the aim of our in vitro investigation was to evaluate the suitability of bacterial cellulose (BC) polymer coupled with gentamicin (GM) antibiotic as an absorbent layer of surgical mesh. Our research included the assessment of GM-BC-modified meshes' cytotoxicity against fibroblasts ATCC CCL-1 and a 60-day duration cell colonisation measurement. The obtained results showed no cytotoxic effect of modified meshes. The quantified fibroblast cells levels resembled a bimodal distribution depending on the time of culturing and the type of mesh applied. The measured GM minimal inhibitory concentration was 0.47 µg/mL. Results obtained in the modified disc-diffusion method showed that GM-BC-modified meshes inhibited bacterial growth more effectively than non-coated meshes. The results of our study indicate that BC-modified hernia meshes, fortified with appropriate antimicrobial, may be applied as effective implants in hernia surgery, preventing risk of infection occurrence and providing a high level of biocompatibility with regard to fibroblast cells.

A multicenter prospective audit to investigate the current management of patients undergoing anti-reflux surgery in the UK: Audit & Review of Anti-Reflux Operations & Workup.

BACKGROUND: There are a variety of surgical and endoscopic interventions available to treat gastroesophageal reflux disease. There is, however, no consensus on which approach is best.The aim of this national audit is to describe the current variation in the UK clinical practice in relation to anti-reflux surgery (ARS) and to report adherence to available clinical guidelines. METHODS: This national audit will be conducted at centers across the UK using the secure online web platform ALEA. The study will comprise two parts: a registration questionnaire and a prospective multicenter audit of ARS. All participating centers will be required to complete the registration questionnaire comprising details regarding pre-, peri-, and post-operative care pathways and whether or not these are standardized within each center. Following this, a 12-month multicenter prospective audit will be undertaken to capture data including patient demographics, predominant symptoms, preoperative investigations, surgery indication, intraoperative details, and postoperative outcomes within the first 90 days.Local teams will retain access to their own data to facilitate local quality improvement. The full dataset will be reported at national and international scientific congresses and will contribute to peer-reviewed publications and national quality improvement initiatives. CONCLUSIONS: This study will identify and explore variation in the processes and outcomes following ARS within the UK using a collaborative cohort methodology. The results generated by this audit will facilitate local and national quality improvement initiatives and generate new possibilities for future research in anti-reflux interventions.

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

INTRODUCTION: Inguinal hernia mesh infection (IHMI) is a rare but a significant problem. The aim of this study was to determine whether etiopathogeneses of early-onset and late-onset IHMIs differ in terms of the origin of infectious agents, and route of dissemination. PATIENTS AND METHODS: This was a retrospective cohort study with prospective data collection of patients operated on from 2013 to 2015. Early-onset IHMI was defined as symptoms developed within one year after the index surgery, whereas late-onset IHMI was defined as infection developed later than a year after the index surgery. Age, gender, ASA score, BMI, time from index surgery, isolated infectious agents and possible pathogeneses were analyzed. RESULTS: During the study period, 1438 patients underwent inguinal hernia repair. Sixteen patients (1.1%) had IHMI, of whom nine were early-onset and seven late-onset. The groups were comparable for age (p = .54), gender (p = 1.0), BMI (p = .79), and ASA score (p = 1.0). The most common infectious agent in early-onset IHMI was St. aureus, whereas Enterococci and Enterobacter prevailed in late-onset IHMI. The possible pathogenesis of IHMI in seven patients with early-onset IHMI was primary exogenous infection, whereas in patients with late-onset IHMI the pathogenesis might be hematogenous or contact spread. All patients with IHMI underwent mesh removal. In two patients (one from each group), partial mesh removal was performed previously and IHMI recurred. CONCLUSIONS: Early-onset hernia mesh infection is mostly caused by St. aureus through exogenous contamination, whereas its late-onset counterpart might be a result of hematogenous or contact spread of intestinal flora.

Hybrid: Evolving techniques in laparoscopic ventral hernia mesh repair.

INTRODUCTION: Laparoscopic repair is now the treatment of choice for most cases of ventral/incisional hernia. Although the technique has undergone many refinements, there is no standard technique for difficult or complicated hernias. AIM: The aim of this study was to show the different innovative methods used to treat difficult ventral hernia through hybrid techniques. MATERIALS AND METHODS: A total of 75 (n = 75) patients underwent Laparoscopic Ventral Hernia Hybrid Mesh Repair (LVHHMR) by our surgical unit between January 2014 and December 2016. Three different techniques of repairing the defects were used. Mesh fixation time, post-operative pain score (visual analogue score) and follow-up for pain and recurrence (at 6 months, 12 months and 24 months) were recorded and analysed. RESULTS: Out of 75 patients (20 men and 55 women), the median age was 45 years and body mass index of the patients was 25-35. Types of hernias operated were paraumbilical hernias, incisional and recurrent hernias. The techniques used were (1) laparoscopic adhesiolysis, open sac excision with closure of defect and laparoscopic mesh placement, (2) laparoscopic adhesiolysis, omphalectomy with closure of defect and laparoscopic mesh placement and (3) open adhesiolysis, sac excision with closure of defect and laparoscopic mesh placement. Five patients required analgesics for 48 h. No patients complained of pain at follow-ups (1 month, 6 months, 12 months and 24 months). Mean hospital stay postoperatively was 2-3 days. CONCLUSION: LVHHMR is safe and feasible approach for complicated/difficult ventral hernias. However, further larger studies are required to establish these methods as gold standard.

The use of mesh for inguinal hernia repair in northern Ghana.

BACKGROUND: Despite the recognition that inguinal hernia (IH) repair is cost-effective, repair rates in low- and middle-income countries remain low. Estimated use of mesh in low- and middle-income countries also remains low despite publications about low-cost, noncommercial mesh. The purpose of our study was to assess the current state of IH repair in the northern and transitional zone of Ghana. MATERIALS AND METHODS: A retrospective review of surgical case logs of IH repairs from 2013 to 2017 in 41 hospitals was performed. Multivariate logistic regression was used to determine predictors of mesh use. RESULTS: Eight thousand eighty male patients underwent IH repair. The range of IH repair in each region was 96 to 295 (overall 123) per 100,000 population. Most cases were performed at district hospitals (84%) and repaired nonurgently (93%) by nonsurgeon physicians (66%). Suture repair was most common (85%) although mesh was used in 15%. The strongest predictor of mesh use was when a surgeon performed surgery (odds ratio [OR] 3.13, P <0.001), followed by surgery being performed in a teaching hospital (OR 2.31, P <0.001). Repair at a regional hospital was a negative predictor of mesh use (OR 0.08, P <0.001) as was the use of general anesthesia (OR 0.40, P = 0.001). CONCLUSIONS: Most IH repairs are performed in district hospitals, by nonsurgeon physicians, and without mesh. Rates of repair and the use of mesh are higher than previous estimates in Ghana and Sub-Saharan Africa but not as high as high-income countries.

Adhesion Prevention Efficacy of Composite Meshes Parietex®, Proceed® and 4DryField® PH Covered Polypropylene Meshes in an IPOM Rat Model.

Background: Adhesions to intraperitoneally implanted meshes (IPOM) are a common problem following hernia surgery and may cause severe complications. Recently, we showed that missing peritoneal coverage of the intestine is a decisive factor for adhesion formation and 4DryField® PH (4DF) gel significantly prevents intestine-to-mesh adhesions even with use of uncoated Ultrapro® polypropylene mesh (UPM). The present study investigates adhesion prevention capability of coated Parietex® mesh (PTM) and Proceed® mesh (PCM) in comparison to 4DF treated UPM. Methods: 20 rats were randomized into two groups. A 1.5 x 2 cm patch of PTM or PCM was attached to the abdominal wall and the cecum was depleted from peritoneum by abrasion. After seven days incidence of intestine-to-mesh adhesions was evaluated using Lauder and Hoffmann adhesion scores. Histological specimens were evaluated; statistics were performed using student's t-test. The data were compared with recently published data of 4DF treated uncoated UPM. Results: Use of PTM or PCM did not significantly diminish development of intestine-to-mesh adhesions (adhesion reduction rate PTM: 29%, p = 0.069 and PCM: 25%, p = 0.078). Histological results confirmed macroscopic finding of agglutination of intestine and abdominal wall with the mesh in between. Compared to these data, the use of UPM combined with 4DF gel reveals significantly better adhesion prevention capability (p < 0.0001) as shown in earlier studies. However, in clinical situation interindividual differences in adhesion induction mechanisms cannot be excluded by this experimental approach as healing responses towards the different materials might vary. Conclusion: This study shows that in case of impaired intestinal peritoneum coated PTM and PCM do not provide significant adhesion prevention. In contrast, use of UPM combined with 4DF gel achieved a significant reduction of adhesions. Hence, in case of injury of the visceral peritoneum, application of a polysaccharide barrier device such as 4DF gel might be considered more effective in reducing intestine-to-mesh adhesions than coated mesh devices.

Impairment of the Peritoneal Surface as a Decisive Factor for Intestinal Adhesions in Intraperitoneal Onlay Mesh Surgery - Introducing a New Rat Model.

BACKGROUND: Meshes implanted intraperitoneally are known to cause adhesions potentially resulting in complications such as chronic pain, enterocutaneous fistula, or mesh infection. This study introduces a model for investigation of intestine-to-mesh adhesions and evaluates as to whether missing of visceral peritoneum is causative. METHODS: In 18 rats, rectangular 1.5 x 2 cm patches of an uncoated polypropylene mesh (Ultrapro(®)) were sewn to the inner abdominal wall next to the cecum. Additionally, a meso-suture ensured contact between cecum and mesh. Rats were assigned to 2 groups: in 8 rats the peritoneum was left intact, in 10 the cecum was depleted from peritoneum with abrasion. Sacrifice was on day 7. Macroscopic evaluation used two adhesion scores. Specimens were evaluated microscopically, statistical analyses employed student's t-test. RESULTS: On day 7, rats with mesh implantation combined with locally de-peritonealization by cecal abrasion mostly showed severe cecum-to-mesh agglutination (mean Lauder score 92%, mean total Hoffmann score 90%), whereas meshes of most animals without cecal abrasion only had some coverage with intraabdominal fat (33%, 24%; p = 0.0002). Histological work-up showed adequate wall ingrowth of mesh in all rats. In animals with cecal abrasion, meshes were mostly adhesive with cecal wall. However, when the peritoneum of cecum was unimpaired, abdominal wall above the mesh as well as cecum usually revealed sub-peritoneal tissue and a mono-layer cell coverage as seen in normal peritoneum. CONCLUSION: This study introduces a model mimicking a clinical situation of e.g. hernia repair by intraperitoneally implanted meshes when mesh has contact with normal and with de-peritonealized intestine. The model might be useful for testing mesh types and coatings as well as other devices for their efficacy in adhesion prevention. The high adhesion scores of rats with local de-peritonealization compared with the low scores of animals with intact peritoneum indicate that the integrity of intestinal peritoneum is a decisive factor for adhesion formation.

Colocutaneous Fistula Formation Following Inguinal Hernia Repair: A Case Series.

Mesh placement remains the standard of care for inguinal hernioplasty, whether through the classic open approach or the transabdominal preperitoneal (TAPP) approach. Though both techniques are generally safe, they can occasionally result in visceral injuries, albeit infrequently. Mesh migration into the intestines is a morbid situation requiring emergency treatment. We present two male patients who developed mesh-enterocutaneous fistula several years after inguinal hernia repair. The first patient with a history of a bilateral TAPP hernia repair was admitted to the emergency department and underwent bilateral complete mesh removal, limited right colectomy, and wedge resection of the sigmoid colon, due to mesh erosion. The second patient, with a history of a left inguinal hernia treated by open mesh repair, presented to the emergency department complaining of intense pain in his left inguinal area. Erosion of the prosthetic mesh into the sigmoid and a colo-cutaneous fistula was identified, with sigmoidectomy and en bloc excision of the adherent mesh and end-colostomy being performed. Mesh erosion into the intestinal tract is a rare but serious condition. In patients presenting with a subcutaneous abscess in the inguinal region, clinicians should maintain a high level of suspicion for intrabdominal inflammation arising from mesh erosion into adjacent viscera. Surgical management becomes necessary in symptomatic cases or instances of fistulization.

Durable and Robust Antibacterial Polypropylene Hernia Mesh for Abdominal Wall Defect Repair.

Polypropylene (PP) mesh is commonly used in repairing abdominal wall hernia (AWH). However, the use of synthetic prosthesis comes with the risk of developing a prosthetic infection, resulting in delayed healing, secondary surgery, and potentially increased mortality. To address these issues, a facile surface functionalization strategy for PP mesh based on phytic acid (PA) and polyhexamethylene guanidine (PHMG) was constructed through a one-step co-deposition process, referred to as the PA/PHMG coating. The development of PA/PHMG coating is mainly attributed to the surface affinity of PA and the electrostatic interactions between PA and PHMG. The PA/PHMG coating could be completed within 4 h under mild conditions. The prepared PA/PHMG coatings on PP mesh surfaces exhibited desirable biocompatibility toward mammalian cells and excellent antibacterial properties against the notorious "superbug" methicillin-resistant Staphylococcus aureus (MRSA) and tetracycline-resistant Escherichia coli (TRE). The PA/PHMG-coated PP meshes showed killing ratios of over 99% against MRSA in an infected abdominal wall hernia repair model. Furthermore, histological and immunohistochemical analysis revealed a significantly attenuated degree of neutrophil infiltration in the PA/PHMG coating group, attributed to the decreased bacterial numbers alleviating the inflammatory response at the implant sites. Meanwhile, the pristine PP and PA/PHMG-coated meshes showed effective tissue repair, with the PA/PHMG coating group exhibiting enhanced angiogenesis compared with pristine PP meshes, suggesting superior tissue restoration. Additionally, PP meshes with the highest PHMG weight ratio (PA/PHMG(3)) exhibited excellent long-term robustness under phosphate-buffered saline (PBS) immersion with a killing ratio against MRSA still exceeding 95% after 60 days of PBS immersion. The present work provides a facile and promising approach for developing antibacterial implants.

Impact of the ventral hernia working group's publication: a bibliometric analysis.

PURPOSE: The Ventral Hernia Working Group (VHWG) proposed a ventral hernia grading guideline, primarily supported by expert opinion, recommending biologic mesh placement in high-risk patients. We investigated the relationship between this industry-sponsored guideline and discourse around ventral hernia repair (VHR). METHODS: Medline platform from Web of Science's database identified publications "pre-VHWG"(1999-01-01 to 2009-12-31), and "post-VHWG"(2010-01-01 to 2020-12-31) describing VHR and complications or recurrence of VHR with the following comorbidities: COPD, smoking, diabetes, immunosuppression, or obesity. Poisson regression analyzed keyword frequency over time using logarithmically transformed data. RESULTS: Of 1291 VHR publications identified pre-VHWG and 3041 publications identified post-VHWG, 172 (13.3%) and 642 (21.1%) publications respectively included prespecified keywords. The keyword groups "biologic"(IRR 3.39,95%CI1.34-11.4,p = 0.022) and "comorbid"(IRR 1.95, 95%CI1.09-3.74,p = 0.033) significantly increased with frequency after publication of the VHWG. CONCLUSION: The VHWG publication likely contributed to a focus on comorbidities and biologic mesh in the ensuing literature within the field of VHR.

Polypropylene Mesh Infection From Surgical Site Infections Caused by Mycobacterium fortuitum.

This report highlights two cases of surgical site infections (SSIs) caused by Mycobacterium fortuitum (Mf) following abdominal mesh implantation. The first case involved an 83-year-old male experiencing non-healing erythema and wounds post-operation, which persisted despite multiple treatments, until effective management was achieved with targeted antibiotics after Mf identification. The second case concerned a female patient with a gynecological postoperative hernia, where Mf was quickly detected following SSI onset three weeks after surgery. Prompt mesh removal and appropriate antibiotic treatment led to a rapid and full recovery. These cases emphasize the importance of early detection and intervention in managing Mf infections effectively, illustrating how the timing of diagnosis can significantly influence treatment outcomes.

Devices in Hernia Surgery.

Despite the heavy reliance of surgeons on mesh with which to repair hernias, less attention is paid to the technical specifications of mesh and/or regulatory processes for bringing medical devices to market during surgical training. This article summarizes some of the key controversies and points regarding mesh materials and regulatory processes related to mesh devices.

Autoimmunity and hernia mesh: fact or fiction?

BACKGROUND: There is an increasing number of patients following hernia surgery with implanted mesh reporting symptoms that could indicate autoimmune or allergic reactions to mesh. 'Allergy' to metals, various drugs, and chemicals is well recognised. However, hypersensitivity, allergy or autoimmunity caused by surgical mesh has not been proven by a scientific method to date. The aim of this study was twofold: to describe the pathophysiology of autoimmunity and foreign body reaction and to undertake a systematic review of surgical mesh implanted at the time of hernia repair and the subsequent development of autoimmune disease. METHODS: A systematic review using the PRISMA guidelines was undertaken. Pubmed (Medline), Google Scholar and Cochrane databases were searched for all English-written peer-reviewed articles published between 2000 and 2021. The search was performed using the keywords "hernia", "mesh", "autoimmunity", "ASIA", "immune response", "autoimmune response". RESULTS: Seven papers were included in the final analysis-three systematic reviews, three cohort studies and one case report. Much of the current data regarding the association of hernia mesh and autoimmunity relies on retrospective cohort studies and/or case reports with limited availability of cofounding factor data linked to autoimmune disease such as smoking status or indeed a detailed medical history of patients. Three systematic reviews have discussed this topic, each with a slightly different approach and none of them has identified causality between the use of mesh and the subsequent development of autoimmune disease. CONCLUSION: There is little evidence that the use of polypropylene mesh can lead to autoimmunity. A large number of potential triggers of autoimmunity along with the genetic predisposition to autoimmune disease and the commonality of hernia, make a cause and effect difficult to unravel at present. Biomaterials cause foreign body reactions, but a chronic foreign body reaction does not indicate autoimmunity, a common misunderstanding in the literature.