Polypropylene Implants Research Articles

THE EFFECT OF A POLYPROPYLENE IMPLANT TREATED WITH THYROTHRICIN ON THE HYPOGASTRIC TISSUES OF THE ABDOMINAL WALL IN RATS

Introduction. The study of tissue reactions to the placement of polymeric materials (polypropylene mesh), used for the treatment of hernias, remains relevant. The paper examines the hypothesis regarding the existence of certain differences in tissue reactions to polypropylene implants without and with treatment of the latter with an antimicrobial agent. Objective of this study is to investigate the reaction of the tissues of the peritoneum and the muscle-aponeurotic layer of the abdominal wall to a polypropylene implant treated with thyrothricin, used for the treatment of complicated variants of inguinal hernias.
 Materials and methods. Experimental studies were conducted on laboratory sexually mature male Wistar rats. Experimental animals made up 4 groups of 5 animals each. The 1st group included control animals (intact). In the rats of the 2nd group, a defect of the abdominal wall of the hypogastric region was surgically modeled. In the animals of the 3rd experimental group, after modeling the defect of the abdominal wall, a polypropylene mesh implant was placed between the peritoneum and the inner leaf of the aponeurosis of the rectus abdominis muscles. The 4th experimental group consisted of animals in which the polypropylene implant was additionally treated with a thyrothricin solution.
 Results. During the experimental study, the integration of tissue elements of the peritoneal walls and the muscle-aponeurotic layer of the abdominal wall with the material of polypropylene meshes was revealed. Active processes of collagenogenesis were observed in the boundary zones and the area of integration with the implant, as well as pronounced manifestations of vascularization of the newly formed connective tissue. The morphological features of the connective tissue formed in the area and around intact implants and meshes treated with thyrothricin did not significantly differ from each other, but significantly prevailed over the condition of the tissues in intact animals. No particular difference between the above-mentioned changes in the tissues of animals of the 3rd and 4th groups was found.
 Conclusion. The obtained results indicate positive biocompatibility of body tissues and polypropylene implants. There is no negative effect of polypropylene nets treated with thyrothricin on body tissues and their regenerative potential.

Comparative assessment of tissue response to a mesh implant made of polypropylene modified with carbon nanotubes and silver nanoparticles

Treatment of abdominal hernias remains one of the most urgent problems of modern surgery. A large number of complications after hernia operations require the development of new types of implants for tissue plastic surgery. The purpose of the study is to carry out an experimental comparative assessment of tissue reaction to the implantation of the developed polypropylene mesh implant modified with carbon nanotubes and silver nanoparticles. Research was conducted on 105 sexually mature laboratory rats in three series of experiments (35 rats each). In the first series, polypropylene mesh implants were implanted in the tissues of the anterior abdominal wall, in the second – polypropylene implants coated with an antiseptic, and in the third – polypropylene implants modified with carbon nanotubes and silver nanoparticles. Animals were removed from the experiment after preliminary anesthesia 3, 5, 7, 14, 21, 30 and 90 days after the operation. The tissues of the abdominal wall were taken together with the implants, histological preparations were made, which were stained with hematoxylin and eosin and according to Van Gieson. We studied the composition and ratio of elements of cell infiltration in tissues with further statistical processing of the obtained data. It was established that during the implantation of mesh edoprostheses, regardless of their type, necrotic changes with reactive inflammation, the presence of inflammatory cell infiltrate, tissue swelling and microcirculation disorders were detected in the tissues 3-5 days after the operation. Under the condition of implantation of the developed mesh, a less pronounced exudative phase of inflammation and an earlier onset of the reparation phase were detected. Depending on the type of implant used, the subsequent reaction differed between the groups of experimental animals, which was evidenced by the regression of inflammatory phenomena in the tissues and the processes of formation of the fibrous capsule around the implants. During the implantation of nanomodified mesh implants by the 7th day of the experiment, the exudative phase of inflammation ended and the formation of a thin connective tissue capsule began, the formation of which was completed by the 21st day of observation, while when the mesh was implanted with polypropylene and polypropylene with an antimicrobial coating, the formation of the capsule lasted up to 30 days. Thus, it was established that the exudative phase of inflammation continues in the tissues around the implantation of classic polypropylene and polypropylene meshes with an antimicrobial coating up to the 14th day of the experiment, and the connective tissue capsule is formed up to the 30th day. At the same time, in the tissues around the mesh implants made of polypropylene modified with carbon nanotubes and silver nanoparticles, the exudative phase of inflammation ended by the 7th day of the experiment. This ensured the intensity of reparative regeneration processes and the separation of the implant from the surrounding tissues by a thin connective tissue capsule for up to 21 days of observation.

Biomaterial based implants caused remote liver fatty deposition through activated blood-derived macrophages

Understanding the biocompatibility of biomaterials is a prerequisite for the prediction of its clinical application, and the present assessments mainly rely on in vitro cell culture and in situ histopathology. However, remote organs responses after biomaterials implantation is unclear. Here, by leveraging body-wide-transcriptomics data, we performed in-depth systems analysis of biomaterials – remote organs crosstalk after abdominal implantation of polypropylene and silk fibroin using a rodent model, demonstrating local implantation caused remote organs responses dominated by acute-phase responses, immune system responses and lipid metabolism disorders. Of note, liver function was specially disturbed, defined as hepatic lipid deposition. Combining flow cytometry analyses and liver monocyte recruitment inhibition experiments, we proved that blood derived monocyte-derived macrophages in the liver underlying the mechanism of abnormal lipid deposition induced by local biomaterials implantation. Moreover, from the perspective of temporality, the remote organs responses and liver lipid deposition of silk fibroin group faded away with biomaterial degradation and restored to normal at end, which highlighted its superiority of degradability. These findings were further indirectly evidenced by human blood biochemical ALT and AST examination from 141 clinical cases of hernia repair using silk fibroin mesh and polypropylene mesh. In conclusion, this study provided new insights on the crosstalk between local biomaterial implants and remote organs, which is of help for future selecting and evaluating biomaterial implants with the consideration of whole-body response.

Features of Cell Reactions during Implantation of Biodegradable Polymer and Polypropylene in the Experiment.

Quantitative and qualitative characteristics of cell infiltrates in male Wistar rats were studied from 14 days to 12 months after implantation of polypropylene and a biodegradable polymer obtained by electrospinning and consisting of 65% polycaprolactone and 35% polytrimethylene carbonate. It was found that a predominantly macrophage-giant cell reaction developed around the biodegradable polymer; it spread into the matrix and the number of cells in the infiltrate decreased, as the degradation progressed. Around polypropylene, mainly lymphocytic and leukocytic reaction was seen; it also decreased with time, but was characterized by a reverse increase in the number of lymphocytes. Immunohistochemical analysis showed that the proportion of CD38+ cells 12 months after implantation increased around polypropylene to a greater extent than around the biodegradable polymer, while the proportion of CD68+ cells decreased. These findings suggest that implantation of a biodegradable polymer caused no prolonged lymphocytic and plasma cell reaction in animals as in the case of polypropylene, which indicates that biodegradable polymer is a promising material for tissue engineering.

The impact of bacterial contamination on the host response towards fully absorbable poly-4-hydroxybutyrate and nonabsorbable polypropylene pelvic floor implants.

Polypropylene (PP) implants for the vaginal surgical correction of pelvic organ prolapse (POP) are known for adverse events, like vaginal or visceral exposures. It is hypothesized that this is a result of a prolonged inflammatory response. One of the triggering factors of prolonged inflammation might be bacterial contamination. A possible solution might lie in an absorbable biomaterial, which provides initial mechanical support while being gradually replaced by the host tissue.With this study we aimed to compare the host response, in a subcutaneous mouse implant infection model, to delayed absorbable poly-4-hydroxybutyrate (P4HB) and a latest generation PP implant. By comparing non-infected to Staphylococcus aureus infected mice, we assessed how bacterial contamination affects the host response and its role in the development of complications. Further, we included sham surgery as a control, mimicking the wound response in native tissue repair.Despite the higher surface area of the P4HB implants, the clearance of infection was similarly delayed in the presence of a P4HB or PP implant, as compared to sham. Further, the host response towards P4HB and PP was quite comparable, yet collagen deposition was significantly increased around infected P4HB implants at early time points. Adverse event rates were similar, though implant exposures were only seen in infected mice and more often with PP (11.1%) than P4HB implants (5.6%). Infected mice overall had significantly higher levels of infiltration of inflammatory cells and lower levels of vascularization and collagen deposition compared to non-infected mice. Thus, for both P4HB and PP, bacterial contamination negatively affected mesh integration by increased inflammation and an increased adverse event rate. Altogether, our results from this subcutaneous mouse implant infection study suggest that P4HB could be a promising degradable alternative to PP, warranting further research to study its potential as a new surgical solution for women with POP.

P095 ARE POLYPROPYLENE MESH IMPLANTS ASSOCIATED WITH SYSTEMIC AUTOIMMUNE/INFLAMMATORY SYNDROMES?

Abstract Aim Worldwide there is a lot of commotion about the effects and complications of mesh implants. The surgical implantation of polypropylene (PP) meshes has been linked to the occurrence of systemic autoimmune disorders (SAIS). We performed a systematic review to determine whether PP implants for inguinal, ventral hernia or pelvic floor surgery are associated with the development of SAIS. Material and Methods We searched Embase, Medline, Web of Science, Scopus, Cochrane library, clinicaltrialsregister.eu, clinicaltrails.gov and WHO-ICTR platform. Forward and backward reference searching was performed to avoid missing relevant papers. All types of studies, except case studies, reporting SAIS in patients having a PP implant for either pelvic floor surgery, ventral or inguinal hernia repair were included. Animal studies were excluded. We intended to perform a meta-analysis. The quality of evidence was assessed with the Newcastle-Ottawa Scale. This study was registered at Prospero (CRD42020220705). Results Of 1938 records identified, 3 were eligible. Two studies involving retrospective matched cohorts focused on mesh surgery for vaginal prolapse or inguinal hernia compared to hysterectomy and colonoscopy, respectively. These reports had a low risk of bias. The third study was a case-series with a high risk of bias, with a sample of 714 patients with systemic disease, 40 of them had PP mesh implanted. A meta-analysis showed no association when comparing systemic disease between mesh and control groups. Calculated Risk Ratio was 0.9 (95%CI 0.78-1.04). Conclusions To date, there is no evidence to suggest a causal relationship between being implanted with a PP mesh and the occurrence of SAIS.

Invasive technologies in the complex treatment of tuberculosis in children and adolescents: from the past to the present (literature review)

Invasive technologies in the complex treatment of tuberculosis in children and adolescents have a long history, which began in the pre-antibiotic period. This is the way of their improvement from independent use of artificial pneumothorax and pneumoperitoneum to the use of these techniques in the complex treatment of respiratory tuberculosis during the development of chemotherapy for the disease. New technology uses valvular bronchial blocking. That procedure creates hypoventilation and atelectasis in the affected region of the lung with preservation of drainage function of the blocked bronchus and destruction cavity, which allow reducing indications for surgical treatment as a method with a high level of injury rate. The approaches to surgical intervention in children and adolescents with respiratory tuberculosis have also changed. It is also part of the comprehensive treatment of the disease. Minimally invasive accesses under the control of video-assisted thoracoscopy are used, which significantly reduced the risk of surgery and increased the immediate efficiency of surgical treatment. New technologies combined with all types of surgeries are being widely developed: electro- and argon plasma coagulation and pleurodesis, vaporization of the tuberculous lesion, and encapsulated pleura by high-energy CO2 laser, new materials (polypropylene implants) are used. Further development of invasive technologies with multiple and extensively drug-resistant Mycobacterium tuberculosis, to children and adolescents compensates for the lack of efficiency of conservative chemotherapy and is an urgent problem at the present stage of pediatric phthisiology.

Morphogenetic Aspects of the Response of Vaginal Tissues to Polypropylene Implants as the Basis of Mesh-Associated Complications.

Morphometric and immunohistochemical examination of the vaginal mucosa before and 12 months after installation of polypropylene implants for the correction of stress urinary incontinence was performed in 20 patients with genital prolapse. The research results confirmed good biocompatibility of polypropylene and the formation of full-fledged connective tissue in the vaginal mucosa, but revealed the presence of a weak lymphocytic reaction to polypropylene 12 months after surgery. According to immunohistochemical study, increased contents of B lymphocytes and plasma cells responsible for the inductive and productive stages of the immune response were revealed in the vaginal mucosa around the implants 12 months after surgery. This reaction in the presences of provoking factors can lead to the development of inflammation and erosion, a type of mesh-associated complications.

A soft elastomer alternative to polypropylene for pelvic organ prolapse repair: a preliminary study.

We compared the impact of a mesh manufactured from the soft elastomer polydimethylsiloxane (PDMS) to that of a widely used lightweight polypropylene (PP) mesh. To achieve a similar overall device stiffness between meshes, the PDMS mesh was made with more material and therefore was heavier and less porous. We hypothesized that the soft polymer PDMS mesh, despite having more material, would have a similar impact on the vagina as the PP mesh. PDMS and PP meshes were implanted onto the vaginas of 20 rabbits via colpopexy. Ten rabbits served as sham. At 12weeks, mesh-vagina complexes were explanted and assessed for contractile function, histomorphology, total collagen, and glycosaminoglycan content. Outcome measures were compared using one-way ANOVA and Kruskal-Wallis testing with appropriate post-hoc testing. Relative to sham, vaginal contractility was reduced following the implantation of PP (p = 0.035) but not the softer PDMS (p = 0.495). PP had an overall greater negative impact on total collagen and glycosaminoglycan content, decreasing by 53% (p < 0.001) and 54% (p < 0.001) compared to reductions of 35% (p = 0.004 and p < 0.001) with PDMS. However, there were no significant differences in the contractility, collagen fiber thickness, total collagen, and glycosaminoglycan content between the two meshes. Despite having a substantially higher weight, PDMS had a similar impact on the vagina compared to a low-weight PP mesh, implicating soft polymers as potential alternatives to PP. The notion that heavyweight meshes are associated with a worse host response is not applicable when comparing across materials.

Comparative Analysis of Connective Tissue Responses to Implantation of Biodegradable Material and Polypropylene in Experimental Animals.

We compared qualitative characteristics of the connective tissue at the site of implantation of polypropylene or a biodegradable polymer synthesized by electrospinning and consisting of 65% polycaprolactone and 35% polytrimethylene carbonate. Synthetic materials were implanted into the interfascial space of the muscles on the back of Wistar rats. The parameters of cellular and non-cellular structures of the forming connective tissue were studied in 1, 2, 3, 6, 9, and 12 months after implantation. It was found that the number of fibrocytes and fibroblasts around biopolymer and polypropylene increased during the period from 1 to 9 months, with a significant lag in case of biopolymer implantation; by 12 months, the number of fibrocytic cells did not significantly differ. The fibroplastic and angioplastic processes developed in the thickness of both materials, but with a one-month lag in case of biopolymer implantation due to degradation properties and nonporous structure of this polymer. Collagen fibers were actively synthesized around both materials, but in case of polypropylene, this process was more pronounced. In 6 months after implantation of polypropylene, dense regular connective tissue was formed; in 12 months after implantation of the biopolymer, the formation of dense irregular connective tissue was observed at the site of implantation. The biopolymer can be used to strengthen the core muscles.

Морфогенетические аспекты реакции тканей влагалища на полипропиленовые имплантаты как основы MESH-ассоциированных осложнений

Морфогенетические аспекты реакции тканей влагалища на полипропиленовые имплантаты как основы MESH-ассоциированных осложнений

ANALYSIS OF POSTOPERATIVE COMPLICATIONS IN REPAIR OFINCISIONAL VENTRAL HERNIAS USING ALLO- AND AUTOGRAFTS

The article provides a multicenter retrospective analysis of postoperative complications in patients after ventral hernias repair. The study went on for 10 years and included 628 patients divided into 2 groups. The first group included 510 patients operated on using polypropylene implants (mesh density 60g/m2 ). In the second group (118 patients) a de-epithelized autodermal graft prepared according to the authors' technology was applied. Clavien-Dindo classification was used to describe postoperative complications. The total number of complications in the first group was 22.2%, in the second group — 2.5% (p &lt; 0.01). In the analysis of complications in all patients operated on using both allo- and autograft, the most frequent complications in the form of seroma were noted when implants using the one lay technique — 22.3% (p &lt; 0.05) were installed. The autodermal de-epithelized graft used in ventral hernia plastics, regardless of their localization and size, especially in relapses after alloplasty, may be a good alternative to synthetic grafts.

In Vitro Bacterial Adhesion and Biofilm Formation on Fully Absorbable Poly-4-hydroxybutyrate and Nonabsorbable Polypropylene Pelvic Floor Implants.

Knitted polypropylene (PP) implants for the correction of pelvic organ prolapse have been associated with complications such as vaginal exposure, infection, and pain. Since certain complications may be linked to bacterial contamination and persistent inflammation, there is a rationale to develop a biocompatible implant that is less prone to bacterial adhesion and biofilm formation. Delayed absorbable materials could meet these requirements and poly-4-hydroxybutyrate (P4HB) might be such a new material for future pelvic floor implants. We studied in vitro bacterial adhesion and biofilm formation on P4HB in comparison to PP. We investigated the influence of both polymers using flat films and compared P4HB and PP implants with different knitting designs. P4HB flat films were demonstrated to be hydrophilic with significantly less Staphylococcus aureus and Escherichia coli cultured from P4HB films than from hydrophobic PP films after 24 h of incubation. On the implants, a higher number of E. coli were cultured after 1 h of incubation from the knitted P4HB implant with the highest density and smallest pore size, compared to other P4HB and PP implants. No differences were observed between the implants for E. coli at later time points or for S. aureus incubation. These results show that in flat films, the polymer influences biofilm formation, demonstrated by a reduced biofilm formation on P4HB compared with PP flat films. In addition, the knitting design may affect bacterial adhesion. Despite certain design and material characteristics that give the knitted P4HB implants a higher surface area, this did not result in more bacterial adhesion and biofilm formation overall. Collectively, these results warrant further (pre)clinical investigations of P4HB pelvic floor implants.

Design of a Novel Reproducible Cartilage-Sparing Autologous Technique for Microtia Repair.

Microtia reconstruction through manual carving of autologous rib cartilage has a steep learning curve, is operator dependent, is time consuming, requires multiple stages, and frequently results in suboptimal results with poor patient satisfaction. The use of temporoparietal fascia over polypropylene implants achieves excellent cosmetic outcomes in a single stage, although is burdened by infection and extrusion in some cases. We describe the development of a hybrid technique with a novel device that allows for standardization of the cartilaginous construct, minimization of the need for donor cartilage and operative time, and minimization of the number of stages. Clinical Trial: NCT03624608.

Fully absorbable poly-4-hydroxybutyrate implants exhibit more favorable cell-matrix interactions than polypropylene

Pelvic organ prolapse (POP) is a multifactorial condition characterized by the descent of the pelvic organs due to the loss of supportive tissue strength. This is presumably caused by the decreased fibroblast function and the subsequent change in the quality of the extracellular matrix. The correction of POP using an implant intends to provide mechanical support to the pelvic organs and to stimulate a moderate host response. Synthetic polypropylene (PP) implants were commonly used for the correction of prolapse. Although they were successful in providing support, these implants have been associated with clinical complications in the long term due to substantial foreign body response and inappropriate tissue integration. The complications can be avoided or minimized by engineering a biocompatible and fully absorbable implant with optimized mechanical and structural characteristics that favor more appropriate cellular interactions with the implant. Therefore, in this study, we evaluated implants comprised of poly-4-hydroxybutyrate (P4HB), a fully absorbable material with high mechanical strength, as an alternative to PP. The P4HB implants were knitted in four unique designs with different pore shapes ranging from a more rectangular geometry- as it is in PP implant- to a rounded geometry, to determine the effect of the implant structure on the textural and mechanical properties and subsequent cell-matrix interaction. The cellular response was investigated by seeding primary vaginal fibroblasts isolated from patients with POP. P4HB favored cellular functions more than PP, as indicated by greater cell attachment and proliferation (P < 0.01), and significantly more collagen deposition (P4HB vs PP, 11.19 μg vs 6.67 μg) at 28 days culture (P < 0.05). All P4HB implants had higher strength and lower stiffness than the PP scaffold. The material and the design of the implant also influenced the behavior of vaginal fibroblasts. The aspect ratio of the vaginal POP fibroblasts cultured on the PP implant (1.61 ± 0.75) was significantly (P < 0.005) smaller than those cultured on P4HB implants (average 2.31 ± 0.09). The P4HB structure with rounded pores showed the lowest stiffness and highest fibroblast attachment and proliferation (P < 0.01). Overall, P4HB induces more matrix deposition compared to PP and knit design can further optimize cell behavior.

Сравнительный анализ реакций соединительной ткани на имплантацию биодеградируемого материала и полипропилена у экспериментальных животных

Сравнительный анализ реакций соединительной ткани на имплантацию биодеградируемого материала и полипропилена у экспериментальных животных

Morphological changes of a great omentum at implantation of polypropylene and composite prostheses at allohernioplasty

To date, allohernioplasty of giant postoperative ventral hernias retains high postoperative mortality and a significant number of postoperative complications. The purpose of the study is to investigate the possibility of intraperitoneal use of polypropylene and composite implants in allohernioplasty of postoperative giant ventral hernias by studying the morphological changes of the great omentum. The results of surgical treatment of 146 patients with postoperative giant ventral hernias were investigated. To this group of patients with allohernioplasty by the method onlay was performed 22 (15.1%) patients, by the method sublay – 46 (31.5%), by the method inlay – 52 (35.6%), with intra-abdominal placement of the mesh by the method onlay (intraperitoneal onlay mesh) – 26 (17.8%). 32 (21.9%) patients who underwent surgery using the sublay method polypropylene implant was fenced off from the abdominal organs with a great omentum, 22 (15.1%) patients operated on by the intraperitoneal onlay mesh method composite implant was also fenced off from the abdominal organs by a great omentum. In 8 (5.5%) patients from the group of patients who were operated on by the sublay method and in 6 (4.1%) – operated by the intraperitoneal onlay mesh method for 14-18 days patients developed signs of chronic intestinal obstruction, where the cause was postoperative adhesive illness. The study of the effect of polypropylene prosthesis on a great omentum was performed on 8 outbred dogs and 6 outbred mature dogs, who were implanted with a composite mesh unilaterally covered with oxycellulose. The polypropylene implant has been shown to have a greater capacity for the development of adhesive processes. However, if a great omentum to protect this prosthesis from the abdominal cavity then the first zone (active inflammation) spread in 155 microns (increase in the number of blood capillaries of the microcirculatory bed, thickening of the arterioles wall, venous full blood flow, diapedesis of leukocytes through the wall of the blood cells), the second zone (sclerosis) – up to 40 microns (increase in the number of macrophages and lymphocytes. proliferation of fibroblasts). In the future, the structure of the omentum was almost indistinguishable, so with allohernioplasty by the developed method, it was possible to prevent the development of adhesive disease on the intestine. This study confirmed the limited spread of the inflammatory response, which allows the implant of a polypropylene mesh on a great omentum. In the composite mesh, the composite mesh was spliced with surrounding tissues from the side where there was no gel coating, and from the side of the salivary coating, the “readiness” to spread the inflammatory process (vasculitis with pronounced lympho-plasmocytic infiltration of the vessel walls and perivascular ductus), therefore, left it is also necessary to enclose it with a large omentum from intestium.

Transvesical laparoendosopic single-site surgery as a valuable option to remove eroded materials from the bladder: single-center experience and a review of the literature

IntroductionCurrently, polypropylene materials are used widely for the treatment of various urogynecologic disorders. This type of treatment can be complicated, although rarely, with erosions of the polypropylene implants into the bladder or the urethra. There is no established treatment for such complications. We present our experience in transvesical laparoendoscopic single-site surgery (T-LESS) removal of eroded materials, and a review of the literature in this field.Materials and methodsFrom June 2015 to May 2017 eight females, with an average age of 66.5 years (range 55–80 years), were referred to our Center because of the erosion of polypropylene material in the bladder, after anti-incontinence or pelvic organ prolapse treatment. Patients were diagnosed with ultrasound and cystoscopy. Seven bladder erosions and one bladder and urethral penetration were found. Patients were qualified for removal with the T-LESS approach. The Tri-Port + disposable set and standard laparoscopic instruments were used. The eroded materials were dissected and cut away, and the defects of the bladder wall were closed with barbed sutures. The peri-operative efficacy and safety of the method were assessed, and the patients were scheduled for follow-up visits at 6 weeks and every 3 months thereafter. The patients were offered a cystoscopic exam during the 7–10 month period after the operation.ResultsThe procedures were completed successfully in all patients. No blood loss or complications were observed. The mean operative time was 54.5 min, and the average hospital stay was 30 h. During a follow-up at 11 months, all patients were cured, except for one who presented urethral erosion.ConclusionsThe T-LESS technique for removal of eroded meshes is a safe and effective method. The precise access to the bladder minimizes morbidity, and suturing the bladder wall defects may reduce the risk of recurrence.

3D reconstruction of MR-visible Fe3 O4 -mesh implants: Pelvic mesh measurement techniques and preliminary findings.

To develop MR-based measurement technique to evaluate the postoperative dimension and location of implanted magnetic resonance (MR)-visible meshes. This technique development study reports findings of six patients (A-F) with cystoceles treated with anterior vaginal MR-visible Fe3 O4 -polypropylene implants. Implanted meshes were reconstructed from 3 months and/or 1 year postsurgical MR-images using 3D Slicer®. Measurements including mesh length, distance to the ischial spines, pudendal, and obturator neurovascular bundles and urethra were obtained using software Rhino® and a custom Matlab® program. The range of implanted mesh length and their placements were reported and compared with mesh design and implantation recommendations. With the anterior/posterior-mesh-segment-ratio mesh shrinkage localization was evaluated. Examinations were possible for patients A-D 3 months and for A, C, E, and F 1 year postsurgical. The mesh was at least 40% shorter in all patients 3 months and/or 1 year postoperatively. A, B showed shrinkage in the anterior segment, D, E in the posterior segment (Patients C, F not applicable due to intraoperative mesh trimming). Patient E presented pain in the area of mesh shrinkage. In Patient C posterior mesh fixations were placed in the iliococcygeal muscle rather than sacrospinous ligaments. Arm placement less than 20 mm from the pudendal neurovascular bundles was seen in all cases. The portion of the urethra having mesh underneath it ranged from 19% to 55%. MRI-based measurement techniques have been developed to quantify implanted mesh location and dimension. Mesh placement variations possibly correlating with postoperative complications can be illustrated.

Morphological and morphometric analysis of tissue changes during implantation of polypropylene mesh implants modified with carbon nanotubes and antiseptics

Despite the introduction of modern materials for the plasticity of tissues in hernia, the results of treatment of this pathology are not entirely satisfied with the surgeons. A large number of complications and hernias recurrences, encourages the search for materials that would not cause tissue reactions to the foreign body and would have the proper antimicrobial properties. We have developed new mesh implants from modified polypropylene with carbon nanotubes and an antiseptic. The aim of the study is to conduct a comparative analysis of the tissue response to the implantation of mesh implants from polypropylene modified with carbon nanotubes and the antiseptic polyhexamethylene guanidine chloride. During the research, international norms and laws of Ukraine on bioethics adhered to. The study was performed on 70 laboratory rats in two series of experiments on 35 animals in each. In the first series, a polypropylene mesh was implanted, and in the second — a developed mesh. The animals were withdrawn from the experiment 3, 7, 14, 21, 30 and 90 days from the start of the experiment, and the material was taken for study. The selected abdominal wall tissues along with the mesh implants were fixed, poured into paraffin and slides were prepared, stained with hematoxylin-eosin and van Gieson, after what was examined under a microscope. The obtained digital data of the studies, in both series of experiments, were compared and subjected to statistical processing. The conducted studies made it possible to establish that caused inflammation by the implantation of the developed nanocomposite implants in the tissues disappear more rapidly than due to classical implants from polypropylene. At the same time, the formation of a connective tissue capsule that dissociated the implants from the tissues was completed before the 14th day of the experiment. At that time around the classical polypropylene implants during this observation period in the tissues minor inflammatory phenomena were observed, and the formation of the connective tissue capsule was completed until to 30 days of observation. So, high biocompatibility of the developed implants with tissues, what creates the prospect of their application in the clinic for the plastic of tissues was experimentally established.