Tension-free synthetic meshes are the clinical standard for hernia repair, but they often trigger immune response-mediated complications such as severe foreign-body reactions (FBR), visceral adhesions, and fibrotic healing, increasing the risk of recurrence. Herein, we developed a hybrid cell membrane coating for macroscale mesh fibers that acts as an immune orchestrator, capable of balancing immune responses with tissue regeneration. Cell membranes derived from red blood cells (RBCs) and platelets (PLTs) were covalently bonded to fiber surfaces using functionalized-liposomes and click chemistry. The fusion of clickable liposomes with cell membranes significantly improved coating efficiency, coverage uniformity, and in vivo stability. Histological and flow cytometric analyses of subcutaneous implantation in rats and mice demonstrated significant biofunctional heterogeneity among various cell membrane coatings in FBR. Specifically, the RBC-PLT-liposome hybrid cell membrane coating markedly mitigated FBR, facilitated host cell infiltration, and promoted M2-type macrophage polarization. Importantly, experimental results of abdominal wall defect repairs in rats indicate that the hybrid cell membrane coating effectively prevented visceral adhesions, promoted muscle regenerative healing, and enhanced the recruitment of Pax7+/MyoD+ muscle satellite cells. Our findings suggest that the clickable hybrid cell membrane coating offers a promising approach to enhance clinical outcomes of hernia mesh in abdominal wall reconstruction.

Postoperative adhesion (PA) caused by the combination of proteins, inflammatory response and bacterial infection poses substantial challenges for polypropylene meshes (PPMs) based hernioplasty. Herein, inspired by the peritoneum, a Janus PPMs with side-specific functions was developed via a surface-initiated photoiniferter-mediated polymerization technology. A physical barrier composed of zwitterionic polymer brushes (PS) was firstly constructed on the one side of the PPMs, while the polymethacrylic acid (PMAA) brushes acting as the linker for bioactive nanoparticles (HAP) were precisely situated on the opposite surface subsequently. Our findings reveal that the mesh surface modified with PS demonstrated significant antifouling property that more than 99% of protein adhesion could be inhibited even after the co-incubation for 72 h in the crucial test. Meanwhile, on the other surface of the PPMs modified with HAP achieved satisfactory ROS-scavenging, inflammation-inhibiting and cell adhesion-promoting properties as well as good bactericidal performance (killing rate > 99.9%). Furthermore, the Janus PPMs could maintain comparable mechanical property with pristine meshes. Equipped with the above multiple merits and asymmetric property, the constructed Janus PPMs demonstrated effective treatment for abdominal hernia defects in vivo without any PA formation. Overall, this study duplicates the unique characteristics of peritoneum onto PPMs to successfully address postoperative complications of the hernioplasty and also offers a versatile and innovative idea to construct asymmetrical functions on the one implant. STATEMENT OF SIGNIFICANCE: The implantation of surgical meshes in the hernia defect provides additional firm support to reinforce the abdomen fascia in tension-free way. However, multiple post-surgery complications induced tissue adhesions is of great challenges for commercial mesh-based hernioplasty. Although material designing and surface modification might circumvent these limitations partly, the construction of side-specific biofunctions on the commercial mesh surfaces is very challenging because of its porous structure. Herein, we demonstrate a feasible and promising approach to construct asymmetric biofunctions on the opposite sides of network structured polypropylene mesh, which is rarely achieved previously. The fabricated Janus PPMs maintains the inherent long-term mechanical support; meanwhile, the opposite sides of PPMs could perform multiple biofunctions independently.

Hernia surgery is a widely performed procedure, and the use of a polypropylene mesh is considered the standard approach. However, the mesh often leads to complications, including the development of scar tissue that wraps around the mesh and causes it to shrink. Consequently, there is a need to investigate the relationship between the mesh and scar formation as well as to develop a hernia mesh that can prevent fibrosis. In this study, three different commercial polypropylene hernia meshes were examined to explore the connection between the fabric structure and mechanical properties. In vitro dynamic culture was used to investigate the mechanism by which the mechanical properties of the mesh in a dynamic environment affect cell differentiation. Additionally, electrospinning was employed to create polycaprolactone spider-silk-like fiber mats to achieve mechanical energy dissipation in dynamic conditions. These fiber mats were then combined with the preferred hernia mesh. The results demonstrated that the composite mesh could reduce the activation of fibroblast mechanical signaling pathways and inhibit its differentiation into myofibroblasts in dynamic environments.

Surgical meshes have demonstrated greater reliability compared to suture repair for abdominal wall hernia treatment. However, questions remain regarding the properties of these devices and their influence on surgical outcomes. Morphological properties, including pore size and porosity, play a crucial role in mesh integration and encapsulation. In this study, we introduce a straightforward image analysis procedure for accurately calculating both textile porosity and effective porosity. The latter specifically considers pores that prevent bridging, providing valuable insights into mesh performance.

A photographic setup was established to capture high-quality images of the meshes, accompanied by calibration images necessary for computing the effective porosity. The developed image analysis procedure comprises seven steps focused on improving the binarization process's quality, followed by the computation of textile and effective porosities. To facilitate usability, an app called "poreScanner" was designed using MATLAB app designer, guiding users through the algorithm described herein. The app was used to compute both porosities on 24 meshes sourced from various manufacturers, by averaging seven measurements obtained from as many images. The app's measurement stability was validated computing the coefficient of variation for both textile and effective porosity, for a total of 36 results (24 for the textile porosity and 12 for the effective one). Additionally, different operators independently tested one heavy and one light mesh, confirming the measurement's operator independence.

The results on the coefficient of variation indicated values below 5 % in 34 out of 36 cases, regardless of the mesh density. Similarly, the same parameter was computed to assess the independence of the procedure from different operators, yielding a maximum value of 1.84 %. These findings confirm the robustness and user-independence of the measurement procedure.

The procedure presented in this study is straightforward to replicate and yields dependable results. Its adoption has the potential to standardize the computation of surgical mesh porosity, enabling consistent determination of this crucial morphological parameter.

Hernia and life-threatening intestinal obstruction often result from abdominal wall injuries, and the regeneration of abdominal wall defects is limited due to the lack of biocompatible, antibacterial and angiogenic scaffolding materials for treating injured tissues. Taking inspiration from the facile preparation of dopamine polymerization and its surface modification technology, in this study, multi-therapeutic copper element was introduced into porcine small intestinal submucosa (SIS) bio-patches through polydopamine (PDA) deposition, in order to regenerate abdominal wall injury. In both in vitro antibacterial assays, cytocompatibility assays and in vivo abdominal wall repair experiments, the SIS/PDA/Cu bio-patches exhibited robust antibacterial efficiency (＞99%), excellent biocompatibility to cells (＞90%), and enhanced neovascularization and improved collagen maturity compared to other commercially available patches (3.0-fold higher than the PP mesh), due to their activation of VEGF pathway. These findings indicated the bio-patch was a promising application for preventing visceral adhesion, bacterial infection, and promoting soft tissue regeneration.

This study developed, a novel polypropylene (PP) mesh combined with poly (L-lactic acid) (PLA) electrospun nanofibers loaded sirolimus (SRL). The PP mesh was combined with PLA/SRL (1/0, 1/0.01, 1/0.02; mass ratios) composed electrospun membrane characterized by FTIR spectroscopy, XPS and SEM, and evaluated for cytocompatibility in vitro. In an in vivo study, a total of 84 Sprague-Dawley rats were employed to evaluate the efficacy of the novel composite PP mesh anti-adhesion, mechanical properties and inflammation. As a results, the PLA/SRL membrane could compound with PP mesh stably and load SRL. Although tensile testing showed that the mechanical properties of composite mesh decreased in vivo, the integration strength between the tissue and mesh was still able to counteract intra-abdominal pressure. Compared with the native PP mesh group, the novel PP mesh group showed a lower score for abdominal adhesion and inflammation. More importantly, the novel PP mesh completely integrated with the abdominal wall and had sufficient mechanical strength to repair abdominal wall defects.

Implantable meshes used in tension-free repair operations facilitate treatment of internal soft-tissue defects. However, clinical meshes fail to achieve anti-deformation, anti-adhesion, and pro-healing properties simultaneously, leading to undesirable surgery outcomes. Herein, inspired by the peritoneum, a novel biocompatible Janus porous poly(vinyl alcohol) hydrogel (JPVA hydrogel) is developed to achieve efficient repair of internal soft-tissue defects by a facile yet efficient strategy based on top-down solvent exchange. The densely porous and smooth bottom-surface of JPVA hydrogel minimizes adhesion of fibroblasts and does not trigger any visceral adhesion, and its loose extracellular-matrix-like porous and rough top-surface can significantly improve fibroblast adhesion and tissue growth, leading to superior abdominal wall defect treatment to commercially available PP and PCO meshes. With unique anti-swelling property (maximum swelling ratio: 6.4%), JPVA hydrogel has long-lasting anti-deformation performance and maintains high mechanical strength after immersion in phosphate-buffered saline (PBS) for 14 days, enabling tolerance to the maximum abdominal pressure in an internal wet environment. By integrating visceral anti-adhesion and defect pro-healing with anti-deformation, the JPVA hydrogel patch shows great prospects for efficient internal soft-tissue defect repair.

The objective of this study was to evaluate the long-term anatomical and functional efficacy, but also the safety of tension-free vaginal mesh in cystocele repair.

This retrospective and monocentric study included 90 women who underwent a prolapse repair between June 2006 and November 2008. A light-weight polypropylene vaginal mesh (22g/m2, Novasilk COLOPLAST®) was used without any fixation. Females were followed at 1 month, 1 year, 3 years and 6 years. Only long-term results are presented in this study. The anatomical result was assessed by the POP-Q classification and the functional results by standardized symptoms (PFDI-20), sexuality (PISQ-12) and quality of life (PFIQ-7) questionnaires.

6 years after surgery, the follow-up rate was 74%. Anatomically, the prolapse recurrence rate (Ba≥0) was 17% (n=8). Functionally, the overall patient satisfaction rate was 89%. Quality of life and symptoms scores (4,11±8.45 vs. 17.5±14.4 and 35.8±15.9 vs 94±23.4 respectively) were significantly improved (p<0.001). Concerning the prevalence of the complication, the retraction and exposition rate was 1.7% (n=1) and a re-intervention rate was 6.7% (n=4). The rate of de novo dyspareunia was 1.7% (n=1).

In this short retrospective series of vaginal mesh interposition for cystocele repair, the prevalence of medium-term patient satisfaction was high.

To assess position of mesh endoprosthesis in retroperitoneal space after TARR hernioplasty using ultrasound in early and long-term postoperative period.

There were 30 patients with inguinal hernias after TARR procedure. Standard technology of laparoscopic transabdominal preperitoneal hernioplasty was used in all patients. In all cases, a large-pore monofilament polypropylene mesh 10x15 cm was used. Control examination and ultrasound of the mesh implant were performed the next day, in 1, 3, 6, 12 months after surgery. Correct position of the implant was determined by its placement at the level of pubic bone with complete overlap of posterior wall of the inguinal canal and inner ring.

US-image of the implant is present in two geometric forms - linear and sinusoid. The shape of prosthesis varies depending on postoperative period and the use of fixing elements. Thus, sinusoidal shape of prosthesis was observed in patients without fixation of prosthesis the next day and in 1 month after TARR. Geometry of the implant acquired the form of a straight line after 3 months and became almost a straight line in 12 months after surgery. Linear shape of prosthesis in early postoperative period was found after intraoperative fixation of endoprosthesis. Sinusoidal shape is noted after 3 months. Ultrasonic pattern of endoprosthesis looked as a thin hyperechoic band with thickness of 1.2-3.9 mm. Mean thickness of prosthesis was 2.2±0.1 mm the next day after surgery, 2.8±0.2 mm after 1 month and 1.6±0.05 mm after 12 months.

Geometry of synthetic implants after TARR hernioplasty undergoes significant changes and depends on duration of postoperative period and fixation of the prosthesis.

Background: The linear geometry of the meshes undergoes significant changes after the transabdominal preperitoneal (TAPP) inguinal hernia repair, caused not only by the presence or absence of mesh fixation but also by reparative processes occurring in the area of surgical intervention. Objective: To assess the position of mesh in the preperitoneal space after the TAPP inguinal hernia repair using ultrasonography in the immediate and late postoperative periods. Materials and Methods: A total of 65 patients who underwent inguinal hernia repair with TAPP were examined. In all cases, a lightweight large-pore monofilament polypropylene mesh (size 10 × 15 cm) was used as a prosthesis. Follow-up examinations and ultrasonography of the mesh were carried out on the first postoperative day and at 1, 3, 6, and 12 months of the follow-up period. Results: Ultrasonography demonstrated mesh in two distinctly different appearances. Although it was seen as an echogenic structure with mild acoustic shadowing, the shape was either wavy or straight linear depending on the method and time elapsed from surgery. Thus, in patients without mesh fixation, it has a wavy appearance on the first day and at 1 month after TAPP, whereas at 3 months it took the appearance of a straight line, and at 12 months the implant has retained the shape of a straight line. Among patients who underwent mesh fixation in the immediate postoperative period, implant appeared as a straight line, and starting from the third month it began to acquire a wavy outline. Conclusion: Geometry of mesh used for TAPP inguinal hernia repair undergoes significantly different changes depending on the method of mesh fixation and time of postoperative period.

Literature review is devoted to the main implants used in hernia surgery and their disadvantages. Advisability of titanium mesh implants in surgery of anterior abdominal wall hernias is shown.

The Lichtenstein technique is used worldwide because of its rapid learning curve, good results and low recurrence rates. In this approach, a lateral tie-shaped incision is made on the mesh, involving the spermatic funiculus and thus correcting the deep inguinal ring defect by narrowing it. The lateral tie, however, does not prevent the wrinkling of the upper portion of the mesh that is caused by the arched shape of the inguinal ligament, where the lower edge of the prosthesis is sutured.

To describe a variation of the Lichtenstein technique that is easy to perform, maintains the advantages and prevents wrinkling of the mesh and allows for better mesh accommodation in the inguinal region.

The main feature of this approach is to cut the mesh vertically and to make the tie over the spermatic cord by overlapping the two resulting portions without wrinkling them. The final appearance is clearly more anatomical, allowing the mesh to be perfectly adapted for each patient.

We operated on consecutive patients using this approach for more than 5 years. There have been no recurrences or specific mesh complications during follow-up, and the surgical aspect of this technique was clearly more anatomical.

This method appears to be easier to perform and the surgical aspects of the technique are more anatomical for the patient.

Worldwide, more than 20 million patients undergo groin hernia repair annually. The many different approaches, treatment indications and a significant array of techniques for groin hernia repair warrant guidelines to standardize care, minimize complications, and improve results. The main goal of these guidelines is to improve patient outcomes, specifically to decrease recurrence rates and reduce chronic pain, the most frequent problems following groin hernia repair. They have been endorsed by all five continental hernia societies, the International Endo Hernia Society and the European Association for Endoscopic Surgery.

An expert group of international surgeons (the HerniaSurge Group) and one anesthesiologist pain expert was formed. The group consisted of members from all continents with specific experience in hernia-related research. Care was taken to include surgeons who perform different types of repair and had preferably performed research on groin hernia surgery. During the Group's first meeting, evidence-based medicine (EBM) training occurred and 166 key questions (KQ) were formulated. EBM rules were followed in complete literature searches (including a complete search by The Dutch Cochrane database) to January 1, 2015 and to July 1, 2015 for level 1 publications. The articles were scored by teams of two or three according to Oxford, SIGN and Grade methodologies. During five 2-day meetings, results were discussed with the working group members leading to 136 statements and 88 recommendations. Recommendations were graded as "strong" (recommendations) or "weak" (suggestions) and by consensus in some cases upgraded. In the Results and summary section below, the term "should" refers to a recommendation. The AGREE II instrument was used to validate the guidelines. An external review was performed by three international experts. They recommended the guidelines with high scores. The risk factors for inguinal hernia (IH) include: family history, previous contra-lateral hernia, male gender, age, abnormal collagen metabolism, prostatectomy, and low body mass index. Peri-operative risk factors for recurrence include poor surgical techniques, low surgical volumes, surgical inexperience and local anesthesia. These should be considered when treating IH patients. IH diagnosis can be confirmed by physical examination alone in the vast majority of patients with appropriate signs and symptoms. Rarely, ultrasound is necessary. Less commonly still, a dynamic MRI or CT scan or herniography may be needed. The EHS classification system is suggested to stratify IH patients for tailored treatment, research and audit. Symptomatic groin hernias should be treated surgically. Asymptomatic or minimally symptomatic male IH patients may be managed with "watchful waiting" since their risk of hernia-related emergencies is low. The majority of these individuals will eventually require surgery; therefore, surgical risks and the watchful waiting strategy should be discussed with patients. Surgical treatment should be tailored to the surgeon's expertise, patient- and hernia-related characteristics and local/national resources. Furthermore, patient health-related, life style and social factors should all influence the shared decision-making process leading up to hernia management. Mesh repair is recommended as first choice, either by an open procedure or a laparo-endoscopic repair technique. One standard repair technique for all groin hernias does not exist. It is recommended that surgeons/surgical services provide both anterior and posterior approach options. Lichtenstein and laparo-endoscopic repair are best evaluated. Many other techniques need further evaluation. Provided that resources and expertise are available, laparo-endoscopic techniques have faster recovery times, lower chronic pain risk and are cost effective. There is discussion concerning laparo-endoscopic management of potential bilateral hernias (occult hernia issue). After patient consent, during TAPP, the contra-lateral side should be inspected. This is not suggested during unilateral TEP repair. After appropriate discussions with patients concerning results tissue repair (first choice is the Shouldice technique) can be offered. Day surgery is recommended for the majority of groin hernia repair provided aftercare is organized. Surgeons should be aware of the intrinsic characteristics of the meshes they use. Use of so-called low-weight mesh may have slight short-term benefits like reduced postoperative pain and shorter convalescence, but are not associated with better longer-term outcomes like recurrence and chronic pain. Mesh selection on weight alone is not recommended. The incidence of erosion seems higher with plug versus flat mesh. It is suggested not to use plug repair techniques. The use of other implants to replace the standard flat mesh in the Lichtenstein technique is currently not recommended. In almost all cases, mesh fixation in TEP is unnecessary. In both TEP and TAPP it is recommended to fix mesh in M3 hernias (large medial) to reduce recurrence risk. Antibiotic prophylaxis in average-risk patients in low-risk environments is not recommended in open surgery. In laparo-endoscopic repair it is never recommended. Local anesthesia in open repair has many advantages, and its use is recommended provided the surgeon is experienced in this technique. General anesthesia is suggested over regional in patients aged 65 and older as it might be associated with fewer complications like myocardial infarction, pneumonia and thromboembolism. Perioperative field blocks and/or subfascial/subcutaneous infiltrations are recommended in all cases of open repair. Patients are recommended to resume normal activities without restrictions as soon as they feel comfortable. Provided expertise is available, it is suggested that women with groin hernias undergo laparo-endoscopic repair in order to decrease the risk of chronic pain and avoid missing a femoral hernia. Watchful waiting is suggested in pregnant women as groin swelling most often consists of self-limited round ligament varicosities. Timely mesh repair by a laparo-endoscopic approach is suggested for femoral hernias provided expertise is available. All complications of groin hernia management are discussed in an extensive chapter on the topic. Overall, the incidence of clinically significant chronic pain is in the 10-12% range, decreasing over time. Debilitating chronic pain affecting normal daily activities or work ranges from 0.5 to 6%. Chronic postoperative inguinal pain (CPIP) is defined as bothersome moderate pain impacting daily activities lasting at least 3 months postoperatively and decreasing over time. CPIP risk factors include: young age, female gender, high preoperative pain, early high postoperative pain, recurrent hernia and open repair. For CPIP the focus should be on nerve recognition in open surgery and, in selected cases, prophylactic pragmatic nerve resection (planned resection is not suggested). It is suggested that CPIP management be performed by multi-disciplinary teams. It is also suggested that CPIP be managed by a combination of pharmacological and interventional measures and, if this is unsuccessful, followed by, in selected cases (triple) neurectomy and (in selected cases) mesh removal. For recurrent hernia after anterior repair, posterior repair is recommended. If recurrence occurs after a posterior repair, an anterior repair is recommended. After a failed anterior and posterior approach, management by a specialist hernia surgeon is recommended. Risk factors for hernia incarceration/strangulation include: female gender, femoral hernia and a history of hospitalization related to groin hernia. It is suggested that treatment of emergencies be tailored according to patient- and hernia-related factors, local expertise and resources. Learning curves vary between different techniques. Probably about 100 supervised laparo-endoscopic repairs are needed to achieve the same results as open mesh surgery like Lichtenstein. It is suggested that case load per surgeon is more important than center volume. It is recommended that minimum requirements be developed to certify individuals as expert hernia surgeon. The same is true for the designation "Hernia Center". From a cost-effectiveness perspective, day-case laparoscopic IH repair with minimal use of disposables is recommended. The development and implementation of national groin hernia registries in every country (or region, in the case of small country populations) is suggested. They should include patient follow-up data and account for local healthcare structures. A dissemination and implementation plan of the guidelines will be developed by global (HerniaSurge), regional (international societies) and local (national chapters) initiatives through internet websites, social media and smartphone apps. An overarching plan to improve access to safe IH surgery in low-resource settings (LRSs) is needed. It is suggested that this plan contains simple guidelines and a sustainability strategy, independent of international aid. It is suggested that in LRSs the focus be on performing high-volume Lichtenstein repair under local anesthesia using low-cost mesh. Three chapters discuss future research, guidelines for general practitioners and guidelines for patients.

The HerniaSurge Group has developed these extensive and inclusive guidelines for the management of adult groin hernia patients. It is hoped that they will lead to better outcomes for groin hernia patients wherever they live. More knowledge, better training, national audit and specialization in groin hernia management will standardize care for these patients, lead to more effective and efficient healthcare and provide direction for future research.

The frequency of laparoscopic approaches increased in hernia surgery over the past years. After mesh placement in IPOM position, the real extent of the meshes configurational changes after termination of pneumoperitoneum is still largely unknown. To prevent a later mesh folding it might be useful to place the mesh while it is kept under tension. Conventionally used meshes may lose their Effective Porosity under these conditions due to poor elastic properties. The aim of this study was to evaluate a newly developed elastic thermoplastic polyurethane (TPU) containing mesh that retains its Effective Porosity under mechanical strain in IPOM position in a porcine model. It was visualized under pneumoperitoneum using MRI in comparison to polyvinylidenefluoride (PVDF) meshes with similar structure.

In each of ten minipigs, a mesh (TPU containing or native PVDF, 10 × 20 cm) was randomly placed in IPOM position at the center of the abdominal wall. After 8 weeks, six pigs underwent MRI evaluation with and without pneumoperitoneum to assess the visibility and elasticity of the mesh. Finally, pigs were euthanized and abdominal walls were explanted for histological and immunohistochemical assessment. The degree of adhesion formation was documented.

Laparoscopic implantation of elastic TPU meshes in IPOM position was feasible and safe in a minipig model. Mesh position could be precisely visualized and assessed with and without pneumoperitoneum using MRI after 8 weeks. Elastic TPU meshes showed a significantly higher surface increase under pneumoperitoneum in comparison to PVDF. Immunohistochemically, the amount of CD45-positive cells was significantly lower and the Collagen I/III ratio was significantly higher in TPU meshes after 8 weeks. There were no differences regarding adhesion formation between study groups.

The TPU mesh preserves its elastic properties in IPOM position in a porcine model after 8 weeks. Immunohistochemistry indicates superior biocompatibility regarding CD45-positive cells and Collagen I/III ratio in comparison to PVDF meshes with a similar structure.

To evaluate the effect of implanted S-nitrosoglutathione (GSNO) coating polypropylene mesh in foreign-body response of rats.

Thirty female rats underwent to subcutaneous implant of five polypropylene (PP) fragments: uncoated PP (control); PP polyvinylalcohol (PVA) coated and PP PVA + GSNO (1, 10 and 70 mMol) coated. After euthanasia (4 and 30 days), eight slides were prepared from each animal: hematoxylin-eosin (inflammatory response); unstained (birefringence collagen evaluation); TUNEL technique (apoptosis); and five for immunohistochemical processing: CD-31 (angiogenesis), IL-1 and TNF-α (proinflammatory cytokynes), iNOS (NO synthesis) and MMP-2 (collagen metabolism). The inflammation area, birefringence index, apoptotic index, immunoreactivity and vessel density were objectively measured.

Inflammatory reaction area at 4 days was 11.3, 15.2, 25.1, 17.1 and 19.3% of pure PP, PVA, GSNO 1, 10 and 70 mM, respectively, p = 0.0006 (PP × Others). At 30 days lower inflammatory area was observed in GSNO 10 and 70 mM compared to pure PP (5.3, 5.2 and 11.1%, respectively, p = 0.0001). Vessel density was higher for GSNO 1 mM (25.5%) compared to pure PP (19.6%) at 30 days only, p = 0.0081. Apoptotic index at 4 days was lower for GSNO 1 mM (49.3%) than pure PVA (60.6%), p = 0.0124. GSNO 10 and 70 mM reduced their apoptotic index at 30 days compared to 4 days (49.9 vs. 36.9 and 59.1 vs. 47.5%, respectively, p = 0.0397). Birefringence index, IL-1, TNF, MMP-2 and iNOS were not different.

Depending on concentrations, GSNO can increase angiogenesis, reduce inflammation and apoptosis compared to pure PP, without impact on cytokine, collagen organization/metabolism and endogenous NO synthesis.

To investigate whether there is a difference between Marlex(r) and Dynamesh PP-light Marlex(r) meshes, in the abdominal wall defect correction, on rats in contaminated surgical site.

Twenty-eight Wistar rats were divided into two groups of 14, and four subgroups of seven animals. All subgroups underwent similar surgical procedure. One group received the mesh Marlex(r) and the other Dynamesh PP-light(r) for correction of the defect. Before implanting, the meshes went through a contamination process, on which was used standard solution containing 10 UFC of Escherichia coli. Fragments of the animal's abdominal wall received macroscopic, microscopic and microbiological analysis.

There was no statistical significance in the analysis of macroscopic variables. Accentuated inflammatory process was shown in all subgroups. The foreign body type reaction was mild in all subgroups, except Dynamesh(r)-14, which was moderate with no statistical significance. The microbiological analysis of the meshes was also similar between the subgroups.

There was no difference between the meshes of Marlex(r) and Dynamesh PP-light(r) in the ventral abdominal wall defect correction on rats in contaminated surgical site.

To compare an inflammation score and collagen morphometry after incisional hernia repair with four different meshes at two time points.

Four types of mesh were used to repair an abdominal wall incisional defect in Wistar rats: high-density polypropylene (HW/PP); low-density polypropylene (LW/PP); polypropylene mesh encapsulated with polydioxanone coated with oxidized cellulose (PP/CE); and expanded polytetrafluoroethylene (ePTFE). An inflammation score based on histological analysis and collagen morphometry was performed after 7 and 28 days after operation (POD).

Compared to LW/PP group at 7 POD, HW/PP group had lower (p = 0.014) and PP/CE group had higher inflammation scores (p = 0.001). At 28 POD, higher scores were seen in all the other groups compared to the LW/PP group (HW/PP, p = 0.046; PP/CE, p < 0.001; ePTFE, p = 0.027). Comparing groups individually at 7 and 28 PODs, all demonstrated lower inflammation score values at 28 POD (HW/PP, p < 0.001; LW/PP, p < 0.001; PP/CE, p = 0.002; ePTFE, p = 0.001). At 7 POD, higher amounts of collagen were detected in ePTFE compared to HW/PP (p < 0.001) and LW/PP (p = 0.004) and in PPCE group compared to HW/PP (p = 0.022). At 28 POD, no statistically significant difference was found. Comparing groups individually at 7 and 28 PODs, HW/PP and LW/PP showed larger amounts of collagen at the 28th POD, without any statistically significant differences for the PP/CE and ePTFE groups.

Inflammation scores decreased in all groups at 28 POD. Collagen deposition was higher for non-composite meshes at 28 POD.

Surgical mesh has become an indispensable tool in hernia repair to improve outcomes and reduce costs; however, efforts are constantly being undertaken in mesh development to overcome postoperative complications. Common complications include infection, pain, adhesions, mesh extrusion and hernia recurrence. Reducing the complications of mesh implantation is of utmost importance given that hernias occur in hundreds of thousands of patients per year in the United States. In the present review, the authors present the different types of hernia meshes, discuss the key properties of mesh design, and demonstrate how each design element affects performance and complications. The present article will provide a basis for surgeons to understand which mesh to choose for patient care and why, and will explain the important technological aspects that will continue to evolve over the ensuing years.

The aim of the study was to evaluate the influence of the pore size of a polypropylene mesh on the shrinkage and elasticity of the mesh-tissue complex and the inflammatory reaction to the implant in an open onlay hernia repair.

Twenty-one 10 × 10 cm samples of polypropylene meshes of a different pore size (3.0 × 2.8 mm-PP3, 1.0 × 0.8 mm-PP1 and 0.6 × 0.5 mm-PP.5) were implanted in an onlay position in 21 New Zealand white rabbits. After 90 days of implantation the shrinkage, elasticity and foreign body reaction (FBR) were assessed.

The shrinkage of PP3 was 30.6 ± 4.3 %, PP1 49.3 ± 2.9 % and PP.5 49.5 ± 2.6 %. The shrinkage of PP3 was significantly lower (PP3 × PP1 p = 0.007, PP3 × PP.5 p = 0.005), PP1 and PP.5 were similar. The elasticity was similar. The strength of FBR in mesh pores was similar. The width of foreign body granuloma layers at the mesh-tissue interface was significantly reduced with increasing pore size (inner: PP3 10.1 ± 1.2; PP1 12.5 ± 2.9; PP.5 17.4 ± 5.2 and outer: PP3 21.2 ± 2.5; PP1 30.6 ± 6.3; PP.5 60.4 ± 14.9). All differences between the widths of granuloma layers were statistically significant (p < 0.010). One animal (PP1) was excluded because of a mesh infection.

Implantation of polypropylene mesh of a pore size of 3 mm in an onlay position is associated with a significant reduction of shrinkage in comparison to a 1 mm pore lightweight and 0.5 mm pore heavyweight mesh. A pore size increase to 3 mm is not sufficient for an improvement of mesh-tissue complex elasticity in comparison to a 1 mm pore lightweight and 0.5 mm heavyweight mesh. Polypropylene mesh with enlarged pores to 3 mm is associated with a similar strength of FBR in mesh pores and a reduced foreign body granuloma in comparison to a 1 mm pore lightweight and 0.5 mm pore heavyweight mesh.