A Fibrin Coating Method of Polypropylene Meshes Enables the Adhesion of Menstrual Blood-Derived Mesenchymal Stromal Cells: A New Delivery Strategy for Stem Cell-Based Therapies

Polypropylene (PP) mesh is well-known as a gold standard of all prosthetic materials of choice for the reinforcement of soft tissues in case of hernia, organ prolapse, and urinary incontinence. The adverse effects that follow surgical mesh implantation remain an unmet medical challenge. Herein, it is outlined a new approach to allow viability and adhesion of human menstrual blood-derived mesenchymal stromal cells (MenSCs) on PP surgical meshes. A multilayered fibrin coating, based on fibrinogen and thrombin from a commercial fibrin sealant, was optimized to guarantee a homogeneous and stratified film on PP mesh. MenSCs were seeded on the optimized fibrin-coated meshes and their adhesion, viability, phenotype, gene expression, and immunomodulatory capacity were fully evaluated. This coating guaranteed MenSC viability, adhesion and did not trigger any change in their stemness and inflammatory profile. Additionally, MenSCs seeded on fibrin-coated meshes significantly decreased CD4+ and CD8+ T cell proliferation, compared to in vitro stimulated lymphocytes (p < 0.0001). Hence, the proposed fibrin coating for PP surgical meshes may allow the local administration of stromal cells and the reduction of the exacerbated inflammatory response following mesh implantation surgery. Reproducible and easy to adapt to other cell types, this method undoubtedly requires a multidisciplinary and translational approach to be improved for future clinical uses.

Evaluation of Clinical Performance of TiNi-Based Implants Used in Chest Wall Repair after Resection for Malignant Tumors

In this study, we assessed the outcomes after surgical treatment of thoracic post-excision defects in 15 patients, using TiNi knitted surgical meshes and customized artificial TiNi-based ribs. Methods: Eight patients were diagnosed with advanced non-small cell lung cancer (NSCLC) invading the chest wall, of which five patients were T3N0M0, two were T3N1M0, and one was T3N2M0. Squamous cell carcinoma was identified in three of these patients and adenocarcinoma in five. In two cases, chest wall resection and repair were performed for metastases of kidney cancer after radical nephrectomy. Three-dimensional CT reconstruction and X-ray scans were used to plan the surgery and customize the reinforcing TiNi-based implants. All patients received TiNi-based devices and were prospectively followed for a few years. Results: So far, there have been no lethal outcomes, and all implanted devices were consistent in follow-up examinations. Immediate complications were noted in three cases (ejection of air through the pleural drains, paroxysm of atrial fibrillation, and pleuritis), which were conservatively managed. In the long term, no complications, aftereffects, or instability of the thoracic cage were observed. Conclusion: TiNi-based devices used for extensive thoracic lesion repair in this context are promising and reliable biomaterials that demonstrate good functional, clinical, and cosmetic outcomes.

P101 BIOSYNTHETIC MESH LIMITS ADHESION FORMATION FOLLOWING INCISIONAL HERNIA REPAIR

Aim Adhesions are fibrous bands of scar tissue that form following peritoneal injury, commonly intra-abdominal surgery, and are associated with serious morbidity such as small bowel obstruction and pain. Surgical meshes used for incisional hernia repair are associated with increased incidence and severity of adhesions. There is limited consensus on which mesh may induce the least adhesions following incisional hernia repair, and most previous data has come from experimental animal models. We aimed to evaluate existing primary research to investigate whether biological mesh limits adhesion formation compared to synthetic or biosynthetic mesh when used in patients for incisional hernia repair and also to assess whether there is correlation with existing animal model data. Material and Methods A systematic search was conducted on PubMed and EMBASE. The number of mesh-related adhesions, character of adhesions and adhesion-related complications were documented. Results were compared to previously published results from animal models. Results Thirty-two studies were included, 11 of which did not document whether the adhesions were mesh related. A total of 14,161 participants underwent incisional hernia repair, 8,526 of whom were included in follow-up analysis. Overall, 9.7% developed adhesions. Biological mesh induced a high rate of dense adhesions, whereas biosynthetic mesh induced loose, filmy adhesions suggested to cause fewer complications. These findings were similar to findings from experimental animal models. Conclusions Bio-synthetic mesh was superior in causing fewer and less dense adhesions. Further analysis of mesh-induced adhesion formation on a larger scale is required to fully understand the consequences of different mesh types.

Textile prostheses in abdominal and pelvic surgery

Textile prostheses have been used in abdominal surgery since ancient times. Industrial development of the last one hundred years changed it from simple cloth to highly improved materials that are better integrated and provide superior functional outcomes. Understanding of the physicochemical properties of surgical meshes is essential for the rational choice of the optimal device. This needs to be closely adapted to mechanical and biological conditions of the anatomical region that will be placed in. The quality of the materials and the manufacturing technique are also of great importance, influencing both the mechanical parameters and the integration of the prosthetic material. Although a hard-to-reach concept, the ideal mesh should have high porosity, a monofilamentous structure and it should be composed of durable, non-carcinogenic, non-allergenic, and highly biocompatible materials. These qualities will ensure a good integration of the prosthesis and will make it easy to handle intraoperatively, resulting in a satisfactory clinical outcome. Based on the above considerations, this article aims to bring to light useful manufacturing information regarding textile prostheses used in surgical reconstructions, in order to support surgeons in making the correct and rational choice of the prosthetic material, based on its physicochemical properties, thus avoiding postoperative complications. Textile implants apply to various surgical fields such as abdominal or thoracic wall reconstruction, visceral defect repair, pelvic floor stabilization or tissue replacement. Postoperative complications of mesh use include chronic pain, infection, ulceration of the wound, adhesion formation, intestinal obstruction, recurrence of parietal defect, rejection of the prosthesis, and mesh granuloma

MRI Surveillance of Plastic Material Surgical Meshes: Experimental Model - Interim Results

The number of surgical procedures for abdominal wall defects is increasing, often requiring the insertion of plastic material meshes. Surveillance of patients with inserted plastic meshes requires an accurate determination of the position of the mesh. However, this is a difficult task, depending on the kind of mesh, magnetic resonance imaging (MRI) protocol or consistence of the surrounding tissue (fat, muscle, aponeurosis). The aim of our research was to develop an experimental model to test the ability of MRI to identify the exact position of surgical plastic meshes: polypropylene or polyester. To simulate the placement of a mesh in human body we developed a model built up from two pieces of tissue with dimensions of 40 cm x 20 cm, harvested from a pig with a weight of 120 kg. The meshes were situated for MRI evaluation between the two pieces: abdominal pig muscle respectively suprajacent abdominal pig wall subcutaneous fat, approximately 2 cm high. Five surgical meshes were scanned through six MRI sequences, in view of establishing an optimal MRI scanning protocol and best visible meshes. The MRI scans were evaluated by 5 radiologists with different degrees of training. Our results showed that the experimental model developed by us can be successfully used to test the ability of MRI to visualize different kind of plastic meshes. Also, our experiment has revealed that T1fl2D sequence is the best in highlighting meshes from surrounding tissue, and the best visualized Mesh was number 4, made of polyester. In conclusion, based on our experimental model, we should select a plastic mesh or MRI protocol which will allow an optimal post implantation monitoring. Modern technology of material�s fabrication can help to better identify the mesh itself using MRI scanning.

Autologous fascial slings remain viable at long-term follow-up: a post cystectomy case report

Background Autologous fascial slings (AFS) have been used for a very long time in the treatment of female stress urinary incontinence, but the introduction of synthetic mesh slings placed either retropubicallyor trans-obturator has decreased the need to harvest the autologous rectus muscle fascia, thus reducing invasiveness and operative time. However AFS are still indicated in complicated cases and re-interventions, and the FDA has underlined safety concerns over the use of surgical meshes for the transvaginal repair of prolapsed pelvic organs. Case presentation A 76-year-old woman with muscle-invasivebladder cancer underwent radical cystectomy 16 years after retropubic positioning of an autologous rectus muscle fascial sling for SUI, with complete symptom resolution. The sling was easily identified and removed en bloc with the bladder and urethra, providing an opportunity to histologicallyevaluate the autologous fascial graft after its long permanence in the new position. Histopathological examination demonstrated increased fibroblastic proliferation and formation of capillaries. A slight separation and an increased waviness of the connective fibers were both evident. An increased vascularity was also apparent, including transverse vessels, with clusters of vessels. A relative inflammatory reaction was present in over 300 cells/10 HPF. All these characteristics indicated viable connective tissue. Conclusions AFS remain a valuable surgical option for both primary and recurrent SUI in women, showing high cure rates and low complications in the long-term. The present case, to the best of our knowledge, presents the longest follow-up period of an autologous rectus muscle fascia placed retropubically and its histological evaluation documents characteristics which support its mechanical strength and viability.

3D-Printing of Drug-Eluting Implants: An Overview of the Current Developments Described in the Literature

The usage of 3D-printing for drug-eluting implants combines the advantages of a targeted local drug therapy over longer periods of time at the precise location of the disease with a manufacturing technique that easily allows modifications of the implant shape to comply with the individual needs of each patient. Research until now has been focused on several aspects of this topic such as 3D-printing with different materials or printing techniques to achieve implants with different shapes, mechanical properties or release profiles. This review is intended to provide an overview of the developments currently described in the literature. The topic is very multifaceted and several of the investigated aspects are not related to just one type of application. Consequently, this overview deals with the topic of 3D-printed drug-eluting implants in the application fields of stents and catheters, gynecological devices, devices for bone treatment and surgical screws, antitumoral devices and surgical meshes, as well as other devices with either simple or complex geometry. Overall, the current findings highlight the great potential of the manufacturing of drug-eluting implants via 3D-printing technology for advanced individualized medicine despite remaining challenges such as the regulatory approval of individualized implants.