Adhesion prevention in ventral hernia repair: an experimental study comparing three lightweight porous meshes recommended for intraperitoneal use

Advanced postoperative tissue antiadhesive membranes enabled with electrospun nanofibers

Tissue adhesion is one of the most common postoperative complications, which is frequently accompanied by inflammation, pain, and even dyskinesia, significantly reducing the quality of life of patients. Thus, to prevent the formation of tissue adhesions, various strategies have been explored. Among these methods, placing anti-adhesion membranes over the injured site to separate the wound from surrounding tissues is a simple and prominently favored method. Recently, electrospun nanofibers have been the most frequently investigated antiadhesive membranes due to their tunable porous structure and high porosities. They not only can act as an essential barrier and functional carrier system but also allow for high permeability and nutrient transport, showing great potential for preventing tissue adhesion. Herein, we provide a short review of the most recent applications of electrospun nanofibrous antiadhesive membranes in tendons, the abdominal cavity, dural sac, pericardium, and meninges. Firstly, each section highlights the most representative examples and they are sorted based on the latest progress of related research. Moreover, the design principles, preparation strategies, overall performances, and existing problems are highlighted and evaluated. Finally, the current challenges and several future ways to develop electrospun nanofibrous antiadhesive membranes are proposed. The systematic discussion and proposed directions can shed light on ideas and guide the reasonable design of electrospun nanofibrous membranes, contributing to the development of exceptional tissue anti-adhesive materials in the foreseeable future.

Surgical techniques and effectiveness of laparoscopic resection of abdominal wall desmoid-type fibromatosis and defect reconstruction: a single-center retrospective analysis

PURPOSE

Although the treatment of abdominal wall desmoid-type fibromatosis (DF) has evolved over the past decades, surgical treatment remains an important approach. Previously, surgeries for abdominal DF were mostly performed by laparotomy, which involves massive dissection and significant trauma. Here, we report our single-center experience of the laparoscopic management of abdominal wall DF in young female patients.

METHODS

The clinical data of nine patients diagnosed with abdominal wall DF during January 2020-April 2022 at the Qilu Hospital of Shandong University were retrospectively analyzed. All patients underwent laparoscopic resection of abdominal wall DF and immediate abdominal wall reconstruction (AWR) with mesh augmentation via the intraperitoneal onlay mesh (IPOM) technique.

RESULTS

Laparoscopic DF resection and AWR were successfully performed in all patients. The mean operation time was 175.56 ± 46.20 min. The width of abdominal wall defect was 8.61 ± 3.30 cm. Full- and partial-thickness myofascial closure and reapproximation were performed in five, two, and two patients, respectively. The average mesh size was 253.33 ± 71.01 cm2. The total and postoperative lengths of hospital stay were 11.00 ± 3.46 and 4.89 ± 2.03 days, respectively. Tumor recurred in one patient after 20 months of the resection. Nonetheless, death, herniation, or bulging were not observed in any patient during a mean follow-up of 16.11 ± 8.43 months.

CONCLUSION

Laparoscopic resection of abdominal wall DF and immediate AWR with IPOM mesh reinforcement is safe and reliable for young female patients. Management of such patients should be decided according to the biological behavior, size, and location of tumors.

The Effects of Pectin-Honey Hydrogel in a Contaminated Chronic Hernia Model in Rats

Incisional hernia is a frequent complication after abdominal surgery. A previous study on rats evaluated the use of a Pectin-Honey Hydrogel (PHH)-coated polypropylene (PP) mesh for the healing of acute hernias. However, there are no studies investigating the use of PHH in association with PP mesh in chronic contaminated hernia. The aims of this study are to assess the effectiveness of PHH in promoting abdominal hernia repaired with PP mesh and in counteracting infection. Twenty Sprague Dawley male rats were enrolled and a full thickness defect was made in the abdominal wall. The defect was repaired after 28 days using a PP mesh, and a culture medium (Tryptone Soy Broth, Oxoid) was spread onto the mesh to contaminate wounds in both groups. The rats were randomly assigned to a treated or untreated group. In the treated group, a PHH was applied on the mesh before skin closure. At euthanasia-14 days after surgery-macroscopical, microbiological and histopathological evaluations were performed, with a score attributed for signs of inflammation. An immunohistochemical investigation against COX-2 was also performed. Adhesions were more severe (p = 0.0014) and extended (p = 0.0021) in the untreated group. Bacteriological results were not significantly different between groups. Both groups showed moderate to severe values (score > 2) in terms of reparative and inflammatory reactions at histopathological levels. The use of PHH in association with PP mesh could reduce adhesion formation, extension and severity compared to PP mesh alone. No differences in terms of wound healing, contamination and grade of inflammation were reported between groups.

Abdominal wall hernia repair: from prosthetic meshes to smart materials

Hernia reconstruction is one of the most frequently practiced surgical procedures worldwide. Plastic surgery plays a pivotal role in reestablishing desired abdominal wall structure and function without the drawbacks traditionally associated with general surgery as excessive tension, postoperative pain, poor repair outcomes, and frequent recurrence. Surgical meshes have been the preferential choice for abdominal wall hernia repair to achieve the physical integrity and equivalent components of musculofascial layers. Despite the relevant progress in recent years, there are still unsolved challenges in surgical mesh design and complication settlement. This review provides a systemic summary of the hernia surgical mesh development deeply related to abdominal wall hernia pathology and classification. Commercial meshes, the first-generation prosthetic materials, and the most commonly used repair materials in the clinic are described in detail, addressing constrain side effects and rational strategies to establish characteristics of ideal hernia repair meshes. The engineered prosthetics are defined as a transit to the biomimetic smart hernia repair scaffolds with specific advantages and disadvantages, including hydrogel scaffolds, electrospinning membranes, and three-dimensional patches. Lastly, this review critically outlines the future research direction for successful hernia repair solutions by combing state-of-the-art techniques and materials.

Impact of titanium-coated polypropylene mesh on functional outcome and quality of life after inguinal hernia repair

Objective

This study aims to compare the clinical outcomes of complications, quality of life, and chronic pain between titanium-coated polypropylene mesh and polypropylene mesh after Lichtenstein or TAPP surgery.

Methods

A retrospective cohort study was conducted, involving patients who underwent inguinal hernia repair using Timesh light®, Optilene LP®, or 3DMax™ meshes between January 2020 and May 2022. Based on the surgical method, patients were divided into Lichtenstein and TAPP groups, and further categorized according to the type of mesh used. The primary endpoints assessed postoperative complications, postoperative pain, and postoperative quality of life. Secondary endpoints included postoperative sensation in the surgical area and postoperative recurrence rate.

Results

A total of 180 Lichtenstein procedures and 478 TAPP procedures were included in the analysis after propensity score matching. The findings revealed that patients with titanium-coated polypropylene mesh did not exhibit significant advantages in perioperative data. Within three months to one year after TAPP surgery, patients with the titanium-coated polypropylene mesh reported improved foreign body sensation during activities (P = 0.002) and a lower incidence of chronic pain (P = 0.008). However, after one year, these advantages of titanium-coated polypropylene mesh were no longer significant during activity or at rest. In the TAPP group, the titanium-coated polypropylene mesh depicted advantages in the single score of the SF-36 questionnaire.

Conclusions

The utilization of titanium-coated polypropylene mesh resulted in reduced foreign body sensation and chronic pain in activity within one year after TAPP surgery, significantly enhancing certain aspects of the patient's quality of life compared to polypropylene mesh.

Laparoscopic Intraperitoneal Onlay Mesh (IPOM): Short- and Long-Term Results in a Single Center

The laparoscopic intraperitoneal onlay mesh repair (IPOM) approach has become the most widely adopted technique in the last decade. The role of laparoscopic IPOM in the last years has been resizing due to several limitations. The aim of the present study is to evaluate short- and long-term outcomes in patients who underwent laparoscopic IPOM. This retrospective single-center study describes 170 patients who underwent laparoscopic IPOM for ventral hernia at the General Surgery Unit of Parma University Hospital from 1 January 2016 to 31 December 2020. We evaluated patient, hernia, surgical and postoperative characteristics. According to the defect size, we divided the patients into Group 1 (Ø < 30 mm), Group 2 (30 < Ø < 50 mm) and Group 3 (Ø > 50 mm). A total of 167 patients were included. The mean defect diameter was 41.1 ± 16.3 mm. The mean operative time was different among the three groups (p < 0.001). Higher Charlson Comorbidity Index, obesity and incisional hernia were related to postoperative seroma and obesity alone with SSO. p < 0.001 Recurrence was significantly higher in larger defects (Group 3) and incisional hernia. p < 0.001. This retrospective study suggests that laparoscopic IPOM is a feasible and safe surgical technique with an acceptable complication rate, especially in the treatment of smaller defects up to 5 cm.

Ultra-Fine Polyethylene Hernia Meshes Improve Biocompatibility and Reduce Intraperitoneal Adhesions in IPOM Position in Animal Models

(1) Introduction: The intraperitoneal onlay mesh technique (IPOM) is widely used to repair incisional hernias. This method has advantages but suffers from complications due to intraperitoneal adhesion formation between the mesh and intestine. An ideal mesh minimizes adhesions and shows good biocompatibility. To address this, newly developed multifilamentous polyethylene (PET) meshes were constructed from sub-macrophage-sized monofilaments and studied regarding biocompatibility and adhesion formation. (2) Methods: We investigated fine (FPET, 72 filaments, 11 µm diameter each) and ultra-fine multifilament (UFPET, 700 filaments, 3 µm diameter each) polyethylene meshes for biocompatibility in subcutaneous implantation in rats. Adhesion formation was analyzed in the IPOM position in rabbits. Geometrically identical mono-filamentous polypropylene (PP) Bard Soft® PP meshes were used for comparison. Histologic and immune-histologic foreign body reactions were assessed in 48 rats after 7 or 21 days (four mesh types, with two different mesh types per rat; n = 6 per mesh type). Additionally, two different mesh types each were placed in the IPOM position in 24 rabbits to compile the Diamond peritoneal adhesion score after the same timeframes. The biocompatibility and adhesion score differences were analyzed with the Kruskal–Wallis nonparametric statistical test. (3) Results: Overall, FPET and, especially, UFPET showed significantly smaller foreign body granulomas compared to PP meshes. Longer observation periods enhanced the differences. Immunohistology showed no significant differences in the cellular immune response and proliferation. UFPET demonstrated significantly reduced peritoneal adhesion formation compared to all other tested meshes after 21 days. (4) Conclusions: Overall, FPET and, especially, UFPET demonstrated their suitability for IPOM hernia meshes in animal models by improving major aspects of the foreign body reaction and reducing adhesion formation.

Mesh for Hernia Repair as Cause of Bowel Obstruction

Ventral hernia repairs are commonly treated by abdominal wall repair where a prosthetic mesh is placed over the hernia site, to prevent future hernia recurrences. Risks of a ventral hernia repair include urinary retention, seroma, recurrence, and in rare cases, bowel injury or obstruction. Our patient's clinical presentation and history, supported by an abdominal X-ray and CT findings, were consistent with the diagnosis of small bowel obstruction (SBO) due to adhesions between the patient's small bowel and the mesh used for abdominal wall hernia repair. Our patient underwent an exploratory laparotomy due to exquisite abdominal wall tenderness and evidence of SBO. Appropriate identification of the cause of our patient's SBO, careful and meticulous treatment, and appropriate inpatient monitoring all contributed to a successful outcome.

Polymer Hernia Repair Materials: Adapting to Patient Needs and Surgical Techniques

Biomaterials and their applications are perhaps among the most dynamic areas of research within the field of biomedicine. Any advance in this topic translates to an improved quality of life for recipient patients. One application of a biomaterial is the repair of an abdominal wall defect whether congenital or acquired. In the great majority of cases requiring surgery, the defect takes the form of a hernia. Over the past few years, biomaterials designed with this purpose in mind have been gradually evolving in parallel with new developments in the different surgical techniques. In consequence, the classic polymer prosthetic materials have been the starting point for structural modifications or new prototypes that have always strived to accommodate patients’ needs. This evolving process has pursued both improvements in the wound repair process depending on the implant interface in the host and in the material’s mechanical properties at the repair site. This last factor is important considering that this site—the abdominal wall—is a dynamic structure subjected to considerable mechanical demands. This review aims to provide a narrative overview of the different biomaterials that have been gradually introduced over the years, along with their modifications as new surgical techniques have unfolded.

Behaviour at the peritoneal interface of next-generation prosthetic materials for hernia repair

BACKGROUND

When using a prosthetic material in hernia repair, the behaviour of the mesh at the peritoneal interface is especially important for implant success. Biomaterials developed for their intraperitoneal placement are known as composites and are made up of two different-structure materials, one is responsible for good integration within host tissue and the other is responsible to make contact with the viscera. This study examines the behaviour at the peritoneal level of two composites, the fully degradable Phasix-ST® and the partially degradable Symbotex®. A polypropylene mesh (Optilene®) served as control.

METHODS

Sequential laparoscopy from 3 to 90 days, in a preclinical model in the New Zealand white rabbit, allowed monitoring adhesion formation. Morphological studies were performed to analyse the neoperitoneum formed in the repair process. Total macrophages were identified by immunohistochemical labelling. To identify the different macrophage phenotypes, complementary DNAs were amplified by qRT-PCR using specific primers for M1 (TNF-α/CXCL9) and M2 (MRC1/IL-10) macrophages.

RESULTS

The percentage of firm and integrated adhesions remained very high in the control group over time. Both composites showed a significant decrease in adhesions at all study times and in qualitative terms were mainly loose. Significant differences were also observed from 7 days onwards between the two composites, increasing the values in Phasix over time. Neoperitoneum thickness for Phasix was significantly greater than those of the other meshes, showing mature and organized neoformed connective tissue. Immunohistochemically, a significantly higher percentage of macrophages was observed in Symbotex. mRNA expression levels for the M2 repair-type macrophages were highest for Phasix but significant differences only emerged for IL-10.

CONCLUSIONS

Fewer adhesions formed to the Symbotex than Phasix implants. Ninety days after implant, total macrophage counts were significantly higher for Symbotex, yet Phasix showed the greater expression of M2 markers related to the tissue repair process.

Experimental evaluation of intra-abdominal adhesions comparing two different intraperitoneal meshes and the effect of a natural anti-inflammatory product on their formation

Purpose:

In laparoscopic incisional hernia repair, meshes with a tissue-separating barrier are positioned intraperitoneally. Despite this property, the close contact between mesh and viscera involves a risk of adhesion formation. Some natural products, such as red propolis (RP), could reduce these adhesions owing to their anti-inflammatory properties. This study aimed to compare two different intraperitoneal meshes with respect to their characteristics of adhesion formation, histological findings and evaluate the role of RP in the development of these adhesions.

Methods:

40 Wistar rats received placement of two different meshes (Symbotex and Dynamesh IPOM) on peritoneum. The animals were divided into two groups: control group (mesh) and treatment group (mesh and RP). After 7 and 14 days, 20 animals of each group underwent midline laparotomy to determine the adhesions and histological characteristics.

Results:

Out of the 40 animals, there were two deaths in the test group and two in the control group. All animals in both groups developed adherence to the mesh. At postoperative day (POD) 7, two Symbotex meshes presented firm adhesions and at POD 14, two Dynamesh meshes had firm adhesions as well. The comparison between the meshes under the effect of RP in relation to the control group showed no statistical difference.

Conclusions:

Both meshes showed intraperitoneal adhesions in all evaluated samples with similar results on the characteristics of adhesions. RP showed no effect on the incidence or gradation of intraperitoneal adhesions with the mesh.

Re-do surgery after prosthetic abdominal wall repair: intraoperative findings of mesh-related complications

INTRODUCTION

Mesh repair is one of the most popular technique for the treatment of abdominal wall hernias, resulting in lower recurrence rates. However, it is associated with a high risk of mesh-related complications. The aim of the present study is to assess the impact of biomaterials on the intra-abdominal organs, in terms of adhesions and visceral complications, in a series of patients undergoing re-do surgery at our abdominal wall unit.

MATERIALS AND METHODS

We reviewed the clinical records of 301 patients who undergone laparotomy between June 2008 and May 2018, selecting 67 patients with one or more previous prosthetic abdominal wall repair (AWR).

RESULTS

The average number of previous repairs was 1.6 with a mean time interval of 66 months from the last repair. Clinical presentation included hernia recurrence (69%), mesh infection (26%), infection and recurrence (10%), and fistula (1%). Adhesions were intraoperatively observed in all patients, except for eight cases. Mesh was completely removed in 43 patients, partially in four. Postoperative complications were observed in 39% of cases, including wound dehiscence, hematoma, seroma, and mesh infection.

CONCLUSIONS

Long-term implant results in abdominal wall repair and are not completely known, and literature is still lacking on this topic. Re-do surgery for subsequent pathological events may represent a way to increase our knowledge.

Postoperative ileus after laparoscopic primary and incisional abdominal hernia repair with intraperitoneal mesh (DynaMesh®-IPOM versus Parietex™ Composite): a single institution experience

PURPOSE

Laparoscopic primary or incisional abdominal hernia repair with intraperitoneal mesh placement is a well-accepted and safe technique. Evidence for complications however remains inconclusive, and little is known about the occurrence of postoperative ileus secondary to postoperative intra-abdominal adhesions with different types of IPOM meshes used. Therefore, we retrospectively compared the occurrence of postoperative ileus between two of the different meshes used in our center.

METHODS

Three hundred seventy-five patients who underwent ventral hernia repair with intraperitoneal mesh placement, either with a DynaMesh®-IPOM (FEG Textiltechnik mbH, Aachen, Nordrhein-Westfalen, Germany) or a Parietex™ Composite mesh (Medtronic, Minneapolis, MN, USA), at the Heilig-Hart Hospital in Lier (Antwerp, Belgium) between 2012 and 2017 were retrospectively compared with regard to the occurrence of postoperative ileus until 6 weeks postoperatively. Baseline demographics and clinical data up to 6 weeks postoperatively of the patients in the two mesh groups are provided.

RESULTS

The DynaMesh®-IPOM mesh group was associated with a significantly higher incidence of postoperative ileus compared with the Parietex™ Composite mesh group with a cutoff limit at postoperative day 1 (n = 17, 6.8% vs. n = 0, 0.0%; P = 0.003) and postoperative day 4 (n = 13, 5.2% vs. n = 0, 0.0%, P = 0.006), even with a mesh surface area of ≤ 300 cm² and when both meshes were fixated with the same method of fixation (Securestrap™) with a cutoff limit for postoperative ileus at postoperative day 1 (n = 4, 7.7% vs. n = 0, 0.0%; P = 0.013) and postoperative day 4 (n = 3, 5.8% vs. n = 0, 0.0%, P = 0.040). Of the 17 patients with a postoperative ileus, 9 (52.9%) had a suspicion of adhesive small bowel obstruction on CT scan (P = 0.033) with definitive confirmation of small bowel adhesions with the DynaMesh®-IPOM mesh at laparoscopy in 2 patients.

CONCLUSION

Our results confirm current literature available regarding postoperative ileus secondary to postoperative intra-abdominal adhesions with the DynaMesh®-IPOM mesh. However, further research with well-designed, multicenter randomized controlled studies to evaluate the use and related complications of these meshes is needed.

Regulation of Peritoneal Inflammatory Response to Implant Material Using an Ex Vivo Model System

BACKGROUND

Implants used in abdominal wall reconstruction are associated with intra-abdominal inflammation that can cause complications such as adhesions, fistulae, or failure of the implant. This study analyzed the inflammatory response of human peritoneum explants when exposed to different implant materials including synthetic and biological (cross-linked and non-cross-linked).

MATERIALS AND METHODS

Human peritoneum explants (parietal and visceral) were incubated in culture with implants used for abdominal wall reconstruction. Implants included Permacol (biological implant with chemical cross-linking); Biodesign and Strattice (biological implants without chemical cross-linking); Prolene (synthetic nonabsorbable); and Vicryl (synthetic absorbable). Control peritoneum samples were incubated without implant. Cytokine concentrations and corresponding gene expression were measured by enzyme-linked immunosorbent assay and quantitative polymerase chain reaction, respectively. Further evaluation included assessment of tissue viability and implant-cytokine adsorption.

RESULTS

Incubation of human peritoneal explants with Biodesign or Strattice was associated with a significant reduction in interleukin-6, interleukin-1β, and tumour necrosis factor alpha protein and gene expression compared with control. These could not be explained by reduced cell viability or implant-cytokine adsorption. Incubation of explants in Biodesign-conditioned media displayed a similar effect to incubation of explants with Biodesign itself.

CONCLUSIONS

Human peritoneal explants cultured with different mesh implant materials show an altered inflammatory cytokine response suggesting a tissue-specific response. Downregulation of key inflammatory cytokines by the peritoneum exposed to non-cross-linked biological implants may be mediated by the release of soluble factors from these implants inhibiting cytokine gene expression. This ex vivo human peritoneal system provides a novel preclinical model to investigate peritoneum-implant interactions.

[Titanium mesh implants in herniology]

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.

Assessment of short-term outcome with TiO2 mesh in laparoscopic repair of large paraesophageal hiatal hernias

Background

Laparoscopic large para-oesophageal hiatal hernia (LPHH) repair using mesh reinforcement significantly reduces postoperative recurrence rates compared to conventional suture repair, especially within short follow-up times. However, the ideal strategy for repairing LPHH remains disputable because no clear guidelines are given regarding indications, mesh type, shape or position. The aim of this study was to survey our short-term results of LPHH management with a biosynthetic monofilament polypropylene mesh coated with titanium dioxide to enhance biocompatibility (TiO₂Mesh™).

Methods

A retrospective study was performed at Ramon y Cajal University Hospital, Spain from December 2014 to October 2018. Data were collected on 27 consecutive patients with extensive hiatal hernia defects greater than 5 cm for which a laparoscopic repair was performed by primary suture and additional reinforcement with a TiO₂Mesh™. Study outcomes were investigated, including clinical and radiological recurrences, dysphagia and mesh-related drawbacks.

Results

Twenty-seven patients were included in our analysis; 10 patients were male, and 17 were female. The mean age was 73 years (range, 63–79 years). All operations were performed laparoscopically. The median postoperative hospital stay was 3 days. After a mean follow-up of 18 months (range, 8-29 months), only 3 patients developed clinical recurrence of reflux symptoms (11%), and 2 had radiological recurrences (7%). No mesh-related complications occurred.

Conclusions

TiO₂Mesh™ was found to be safe for laparoscopic repair of LPHH with a fairly low recurrence rate in this short-term study. Long-term studies conducted over a period of years with large sample sizes will be essential for confirming whether this mesh is suitable as a standard method of care with few drawbacks.

Primary non-complicated midline ventral hernia: is laparoscopic IPOM still a reasonable approach?

PURPOSE

Ventral hernia repair has become a common procedure, but the way in which it is performed still depends on surgeon's skill, experience, and habit. The initial open approach is faced with extensive dissection and a high risk of infection and prolonged hospital stay. To tackle these problems, minimally invasive procedures are gaining interest. Several new techniques are emerging, but laparoscopic intra-peritoneal onlay mesh (IPOM) is still the mainstay for many surgeons. We will discuss why laparoscopic IPOM is still a valuable approach in the treatment of primary non-complicated midline hernias and review the current literature.

METHODS

We performed a literature search across PubMed and MEDLINE using the following search terms: "Laparoscopic hernia repair", "Ventral hernia repair" and "Primary ventral hernia". Articles corresponding to these search terms were individually reviewed by the primary author and selected on relevance.

CONCLUSION

Laparoscopic IPOM still is a good approach for the efficient treatment of primary non-complicated midline hernias. Several techniques are emerging, but are faced with increased costs, technical difficulties, and low study patient volume. Further research is warranted to show superiority and applicability of these new techniques over laparoscopic IPOM, but until then laparoscopic IPOM should remain the go-to technique.

Comparative study of peritoneal adhesions after intraperitoneal implantation in rats of meshes of polypropylene versus polypropylene/polyglecaprone versus polyester/porcine collagen

PURPOSE

To Compare the extent and intensity of adhesions formed between the intra-abdominal organs and the intraperitoneal implants of polypropylene mesh versus polypropylene/polyglecaprone versus polyester/porcine collagen used for correction of abdominal wall defect in rats.

METHODS

After the defect in the abdominal wall, thirty Wistar rats were placed in three groups (ten animals each) for intraperitoneal mesh implant: polypropylene group, polypropylene/polyglecaprone group, and polyester/porcine collagen group. The macroscopic evaluation of the extent and intensity of adhesions was performed 21 days after the implant.

RESULTS

The polypropylene group had a higher statistically significant impairment due to visceral adhesions (p value = 0.002) and a higher degree of intense adherence in relation to polypropylene/polyglecaprone and polyester/porcine collagen groups (p value<0.001). The polyester/porcine collagen group showed more intense adhesions than the polypropylene/polyglecaprone group (p value=0.035).

CONCLUSIONS

The intraperitoneal implantation of polypropylene meshes to correct defects of the abdominal wall caused the appearance of extensive and firm adhesions to intra-abdominal structures. The use of polypropylene/polyglecaprone or polyester/porcine collagen tissue-separating meshes reduces the number and degree of adhesions formed.

Biological Scaffolds for Abdominal Wall Repair: Future in Clinical Application?

Millions of abdominal wall repair procedures are performed each year for primary and incisional hernias both in the European Union and in the United States with extremely high costs. Synthetic meshes approved for augmenting abdominal wall repair provide adequate mechanical support but have significant drawbacks (seroma formation, adhesion to viscera, stiffness of abdominal wall, and infection). Biologic scaffolds (i.e., derived from naturally occurring materials) represent an alternative to synthetic surgical meshes and are less sensitive to infection. Among biologic scaffolds, extracellular matrix scaffolds promote stem/progenitor cell recruitment in models of tissue remodeling and, in the specific application of abdominal wall repair, have enough mechanical strength to support the repair. However, many concerns remain about the use of these scaffolds in the clinic due to their higher cost of production compared with synthetic meshes, despite having the same recurrence rate. The present review aims to highlight the pros and cons of using biologic scaffolds as surgical devices for abdominal wall repair and present possible improvements to widen their use in clinical practice.

Evaluation of synthetic reticular hybrid meshes designed for intraperitoneal abdominal wall repair: Preclinical and in vitro behavior

Introduction

Reticular hybrid meshes represent an alternative material for intraperitoneal repair of abdominal hernias. These consist of a reticular mesh coated or interwoven/knitted with inert materials. This study assesses the performance of two reticular polypropylene-containing hybrid meshes, TiMESH (coated with titanium) and DynaMesh (interwoven with polyvinylidene fluoride), in vitro, as well as their efficiency in adhesion prevention and tissue incorporation in an intraperitoneal model.

Methods

The mesothelialization capacity of TiMESH and DynaMesh was evaluated in vitro and compared to that of Surgipro (reticular bare polypropylene) and Preclude (laminar expanded polytetrafluoroethylene). Mesh fragments were placed on the intact parietal peritoneum of New Zealand white rabbits (n = 24), and laparoscopy performed 7 days post-surgery. Fourteen days post-implantation, adhesions were evaluated and host tissue incorporation, macrophage response, collagen expression (immunohistochemistry/RT-PCR) and neoperitoneum formation assessed. Adhesions and omental tissue were also examined.

Results

Mesh pores in reticular meshes were devoid of cells in the in vitro study. TiMESH, DynaMesh and Surgipro showed similar adhesion rates at 7/14 days and optimal tissue integration, with significant differences in comparison to Preclude. The greatest presence of macrophages was observed for TiMESH and was significant versus that for Preclude. Hybrid meshes revealed significantly higher collagen 1 mRNA expression in implants, with no differences in the levels of collagen 3. Omental samples from animals with a reticular mesh showed significantly greater collagen 1 mRNA levels.

Conclusions

The reticular structure of a mesh limits the formation of a continuous mesothelial monolayer in vitro, regardless of its composition. The presence of titanium as a coating or polyvinylidene fluoride interwoven with polypropylene in a reticular structure did not prevent adhesions. The hybrid meshes showed proper integration and an increase in the mRNA Col 1 levels in the implant area compared to Surgipro or Preclude.

Biomaterial Implants in Abdominal Wall Hernia Repair: A Review on the Importance of the Peritoneal Interface

Biomaterials have long been used to repair defects in the clinical setting, which has led to the development of a wide variety of new materials tailored to specific therapeutic purposes. The efficiency in the repair of the defect and the safety of the different materials employed are determined not only by the nature and structure of their components, but also by the anatomical site where they will be located. Biomaterial implantation into the abdominal cavity in the form of a surgical mesh, such as in the case of abdominal hernia repair, involves the contact between the foreign material and the peritoneum. This review summarizes the different biomaterials currently available in hernia mesh repair and provides insights into a series of peculiarities that must be addressed when designing the optimal mesh to be used in this interface.

Mussel-inspired copolymer-coated polypropylene mesh with anti-adhesion efficiency for abdominal wall defect repair

Construction of anti-adhesive polypropylene meshes through the in situ copolymerization grafting of poly(ethylene glycol) methacrylate and dopamine methacrylamide.

Biocompatibility of synthetic ultraviolet radiation cross-linked polymers - Subcutaneous implantation study

Photo-cross-linked polymers have attracted a lot of attention in the biomedical field. The main benefits of these materials are related to the fact that they are most of the time viscous liquids or pastes that adapt a custom and fixed shape on demand of the user. Present study deals specifically with the biological response upon subcutaneous implantation of four different materials in rabbits. In the study 20 rabbits were divided into four groups (each five rabbits): Groups 1-3 were implanted with tested new obtained by us macromonomers (P1838-DMA; P1838-UR; PDEGA-UR - respectively), while group 4 (control) was implanted with the mesh (PLA) routinely used for surgical treatment of a hernia. The new compounds were polarized earlier using ultraviolet radiation to obtain cross-linked networks. The polymers in the form of discs were then implanted subcutaneously in dorsal region of rabbits. After 28 days polymers were explanted and examined. Microscopic observation evaluated: thickness of the connective tissue capsule around the discs, cells of inflammatory response, disc surface erosion, spectroscopic analysis. The examined materials cause no chronic inflammation, abscesses or tissue necrosis, and the biological response is similar to observed in control group. Therefore, new synthetic materials could be considered as biocompatible and safe. Materials undergo slow degradation of ester bonds and surface erosion and degradation products could be eliminated probably by phagocytosis. On the basis on the afore mentioned knowledge, we formulated hypothesis, that the new polymers are well tolerated by the adjacent tissues. The aim of the following study was to examine reaction of the tissue on new types of prepolymerized material implanted subcutaneously. The obtained results suggest, that the new UV cross-linked polymers do not affect negatively on the connective tissue that is in the contact with the implants. Furthermore, the used materials are in the liquid form, thus they could be easily performed in in minimally invasive laparoscopic treatment of abdominal hernias. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1889-1897, 2019.

Adhesion Prevention to Polypropylene Meshes Using Combined Icodextrin Four Percent and Dimetindene Maleate

BACKGROUND

The use of surgical meshes in ventral hernia repair has significantly reduced hernia recurrence rates. However, when placed intraperitoneally prosthetic materials can trigger the development of peritoneal adhesions. The present experimental study evaluated the combined icodextrin 4% and dimetindene maleate treatment in preventing peritoneal adhesion formation to polypropylene and titanium-coated polypropylene meshes.

MATERIALS AND METHODS

Sixty female white rabbits were divided into four groups. A 2 × 2 cm piece of mesh was fixed to intact peritoneum in all animals through a midline laparotomy. A lightweight polypropylene mesh was implanted in groups 1 and 2 and a titanium-coated polypropylene mesh in groups 3 and 4. Groups 2 and 4 were treated, intraoperatively, with intravenous dimetindene maleate (0.1 mg/kg) and intraperitoneal solution of icodextrin 4% (20 mL/kg) and for the next 6 d with dimetindene maleate intramuscularly. The observation period lasted 15 d. Adhesion scores, percentage of mesh affected surface, tissue hydroxyproline levels, and tissue histopathology were examined.

RESULTS

All animals in group 1 and 57% of animals in group 3 presented postoperative adhesions. The combination of antiadhesives significantly reduced the extent and severity of adhesions as well as the hydroxyproline levels in groups 2 and 4 compared with groups 1 and 3. On microscopic evaluation, animals in group 1 exhibited higher inflammation scores compared with group 2, whereas animals in groups 2 and 4 had better mesotheliazation compared with groups 1 and 3.

CONCLUSIONS

The combined administration of icodextrin 4% and dimetindene maleate reduces the extent and severity of adhesions and may be successfully used to prevent adhesion formation after mesh intraperitoneal placement.

Chronic anemia due to transmural e-PTFE anti-adhesive barrier mesh migration in the small bowel after open incisional hernia repair: A case report

•

Mesh related unusual complication.

•

Intraluminal mesh migration.

•

Mesh erosion.

Introduction

Meshes are commonly employed in abdominal hernia repair to reduce recurrence rates. Prosthetic repair, however, increases the risk of mesh related complications, including migration into adjacent viscera and erosion which can occur as uncommon and can be difficult to be diagnose.

Presentation of case

This is a case of transmural migration of composite mesh into the bowel, presenting as chronic abdominal pain and anemia 14 years after incisional hernia repair.

Discussion

Mesh implantation in hernia repair has increased the incidence of complications, such as seroma, hematoma and infection. Migration into adjacent viscera and erosion may present as complications related to the use of meshes. Their precise frequency after abdominal wall hernia repair is not well known and their late occurrence can make the diagnosis difficult.

Conclusion

Transmural migration of composite mesh is an uncommon complication of incisional hernia repair. Its pathogenesis is still not completely clear but it has been reported many years after implant surgery. It should be considered in a typical presentation of patients with history of previous prosthetic ventral hernia repair.

Effectiveness of polypropylene mesh coated bovine amniotic membrane with adhesion barrier (polyethylene glycol) in repair of abdominal wall hernias in rats

This study was undertaken to investigate the effectiveness of polypropylene (PP) mesh coated bovine amniotic membrane (BAM) with 5% polyethylene glycol (PEG) 4000 as adhesion barrier in the repair of experimental 2 × 2 cm of abdominal hernias in rats. Rats (32) were divided into 4 groups. A 2 cm × 2 cm defect was created in the full thickness of abdominal muscle on the anterior abdominal wall. PP mesh was implanted in the abdominal cavity (Gr 1 to 4). BAM covered the abdominal face of the graft (Gr 3 and 4). It was given before the abdominal closure 5 ml of 5% PEG 4000 (Gr 2 and 4) and 5 ml of 0.9% NaCl (Gr 1 and 3). After 21 days following the operations, 32 rats were euthanized. Macroscopic and microscopic evaluations were performed according to the scoring systems. The differences between the groups was evaluated by Mann-Whitney U test and Kruskal Wallis analysis of variance. Highest adhesion percentage was observed in Gr 1 and lowest in Gr 4. Inflammatory reaction was observed in Gr 1 and 2. According to the results of this study, the combined use of BAM and 5% PEG 4000 was helpful to prevent the complications of PP mesh.

Robotic TAPP Ventral Hernia Repair: Early Lessons Learned at an Inner City Safety Net Hospital

Background and Objectives

Ventral hernia repair is one of the most commonly performed general surgery procedures, and minimally invasive approaches are increasingly preferred. The physiologic repair offered by the preperitoneal approach is favorable, with reduced complications, but it remains a technical challenge. The robotic platform allows for enhanced instrument flexibility and ease of operation. We conducted a retrospective review of our experience with robotic transabdominal preperitoneal repair (rTAPP) versus robotic intraperitoneal onlay mesh (rIPOM) at a tertiary care hospital in an urban setting.

Methods

We reviewed the records of patients undergoing minimally invasive ventral hernia repair from March 2014 through March 2017. Demographics, complication rates, and operative time were compared by t test and Chi square test, as applicable.

Results

Sixty-three patients met the criteria for inclusion in the study. Of those, 27 underwent ventral hernia repair with rIPOM and 36 with rTAPP, with no major intraoperative complications. There were no significant differences in demographics between the 2 groups in age, BMI, and sex. The difference in mean operative time was not significant (rIPOM 167.26 [SD 51.76] minutes vs rTAPP 158.84 minutes [SD 61.5]; P = .57), whereas mean console time was significantly different (rIPOM 70.88 minutes [SD 32.88] vs rTAPP 90.26 [SD 31.17]; P = .018). Postoperative complications occurred only with rIPOM and included urinary retention, seroma, and fever.

Conclusions

rTAPP is a promising alternative to rIPOM, with reduced complications without adding significant operative time, and may allow for reduced costs.

Surveillance of Surgical Meshes in Ventral Hernias and Unpredictability of Their History

: The authors read the article "The importance of registries in the postmarketing surveillance of surgical meshes" by Kockerling et al, and they completely agree on the role of a clinical follow-up of surgical meshes even if they suggest that a surveillance longer than one year is advisable, particularly in IPOM repair, to collect not only late complications but also more serious adverse events. This seems be the only way to properly assess the safety of the mesh.

Two cases about mesh adhesion to intra-abdominal cavity tissue after using mesh to repair an incisional hernia

Abdominal incisional hernia is a common postoperative complication. With the development of a new type of surgical anti-adhesion mesh, mesh repair has become a widely-adopted procedure, particularly in the laparoscopic era. However, there were few reports about use of these new meshes to repair incisional hernia in the abdominal cavity. In this report, we present two cases: one a 72-year-old male and the other a 62-year-old female. Both of those patients suffered incisional hernias during abdominal operations, and therefore underwent open incisional hernia anti-adhesion mesh repair operations. Both of them had recurrent incisional hernias after the first repair operation. During the second hernia repair operation via laparoscopy, tissue from the intestine and omentum were found to have adhered seriously to the old meshes, which could cause many serious problems. We need to pay more attention to the issue of adhesion, try to determine possible reasons and improve in our future work.