Polypropylene Implants Research Articles

MULTILEVEL SURGICAL CORRECTION OF POSTGISTERECTOMIC GENITAL HERNIA

The article presents a new surgical method for correcting posthisterectomic genital hernia, accompanied by bilateral paravaginal defects. Despite the use of many surgical techniques and high-tech materials for the prevention and treatment of posthisterectomic genital hernia, the prevalence rate of this pathology fails to decline, but on the contrary, for many reasons, it tends to grow, which calls for the development of new surgical methods of the treatment. The proposed surgical program of multilevel correction of posthisterectomic genital hernia with bilateral paravaginal defects, providing multifocal fixation of anatomical structures with polypropylene implants, will improve clinical results and their duration, as well as the fall of the prevalence rate of relapses of the disease.

Biomimetic implants for pelvic floor repair.

Polypropylene implants are used for the reconstructive surgery of urogynaecological disorders like pelvic organ prolapse, but severe complications associated with their use have been reported. There is evidence that surface properties and a difference in mechanical stiffness between the implant and the host tissue contribute to these adverse events. Electrospinning is an innovative engineering alternative that provides a biomimetic microstructure for implants, resulting in a different mechano-biological performance. The main objective of this review is to inform about the potential of electrospun matrices as an alternative modality for pelvic floor repair. Publications with the following studies of electrospun matrices were reviewed: (i) the technique; (ii) in vitro use for soft tissue engineering; (iii) in vivo use for reconstruction of soft tissues in animals; and (iv) clinical use in humans. Electrospun matrices provide a synthetic mimic of natural extracellular matrix (ECM), favoring cellular attachment, proliferation and matrix deposition, through which a proper, low-inflammatory tissue-implant interaction can be established. Electrospun sheets can also be created with sufficient mechanical strength and stiffness for usage in prolapse surgery. Electrospun matrices mimic the structural topography of the extracellular matrix and can be functionalized for better biological performance. As such, they have great potential for the next generation of urogynecological implants. However, their long-term safety and efficacy must still be established in vivo.

Physiologic musculofascial compliance following reinforcement with electrospun polycaprolactone-ureidopyrimidinone mesh in a rat model

PurposeElectrospun meshes may be considered as substitutes to textile polypropylene implants. We compared the host response and biomechanical properties of the rat abdominal wall following reinforcement with either polycaprolactone (PCL) modified with ureidopyrimidinone-motifs (UPy) or polypropylene mesh. MethodsFirst we measured the response to cyclic uniaxial load within the physiological range both dry (room temperature) and wet (body temperature). 36 rats underwent primary repair of a full-thickness abdominal wall defect with a polypropylene suture (native tissue repair), or reinforced with either UPy-PCL or ultra-light weight polypropylene mesh (n = 12/group). Sacrifice was at 7 and 42 days. Outcomes were compliance of explants, mesh dimensions, graft related complications and semi-quantitative assessment of inflammatory cell (sub) types, neovascularization and remodeling. ResultsDry UPy-PCL implants are less stiff than polypropylene, both are more compliant in wet conditions. Polypropylene loses stiffness on cyclic loading. Both implant types were well incorporated without clinically obvious degradation or herniation. Exposure rates were similar (n = 2/12) as well as mesh contraction. There was no reinforcement at low loads, while, at higher tension, polypropylene explants were much stiffer than UPy-PCL. The latter was initially weaker yet by 42 days it had a compliance similar to native abdominal wall. There were eventually more foreign body giant cells around UPy-PCL fibers yet the amount of M1 subtype macrophages was higher than in polypropylene explants. There were less neovascularization and collagen deposition. ConclusionAbdominal wall reconstruction with electrospun UPy-PCL mesh does not compromise physiologic tissue biomechanical properties, yet provokes a vivid inflammatory reaction.

Female genital prolapse surgery using ultra lightweight polypropylene mesh

To compare the results of female genital prolapse (FGP) surgery via vaginal access using lightweight and ultra-lightweight polypropylene mesh. From 2007 to 2011, 93 women aged from 46 to 71 years with II-IV stage FGP (POP-Q classification) were examined and underwent the vaginal extra-peritoneal colpopexy using polypropylene implants in the Department of Urology. Patients were divided into 2 groups. In patients of group 1 (n=50) the surgery was performed according to a newly developed technique using perforated ultra-lightweight (surface density 19 g/m2) domestically manufactured polypropylene implant. In group 2, a standard trocar set with light (surface density of 42.7 g/m2) foreign-made polypropylene implants was used. Long-term follow-up was from 1 to 5 years. General surgical complications (urinary bladder injury, blood loss over 300 ml, perineal and vaginal hematomas) were detected in 2 (4%) patients of group 1 and in 7 (16.3%) patients of group 2. The most common specific mesh-related complication was the vaginal wall erosion, which was observed in 4 (9.3%) patients of group 2 and in 1 (2%) patient of group 1. FGP recurrence was diagnosed in 5 (10%) patients of group 1 in the non-treated part and in 8 (18.6%) patients of group 2. Three patients (7%) in group 2 developed recurrent cystocele due to the shrinkage of the mesh implant which was not observed in group 1. At 12 month follow-up, the results of FGP surgical treatment were estimated as good (full functional recovery and no FGP recurrence) in 41 (82%) and 32 (74.4%) patients of groups 1 and 2, respectively. We have developed a method of vaginal extra-peritoneal colpopexy using a perforated ultra-lightweight polypropylene implant. This technique has resulted in the absence of recurrence in the treated part of FGP, and 4.1, 4.2 and 4.7 fold reductions in the incidence of general surgical complications, vaginal wall erosions and perineal and vaginal hematomas, respectively, compared with FGP patients undergoing the placement of the lightweight polypropylene implant using the standard trocar set.

Morphological and morphometric changes in the tissues of liver and skeletal muscle on implantation of polypropylene and polypropylene-modified carbon nanotubes

Morphological and morphometric changes in the tissues of liver and skeletal muscle on implantation of polypropylene and polypropylene-modified carbon nanotubes

Cranial Polypropylene Implants by Fused Filament Fabrication

This study evaluates the feasibility and suitability of polypropylene (PP) implants produced by Fused Filament Fabrication (FFF) for the substitution of damaged cranial bone material from the polymer‐engineering point of view. The establishing of imaging methods, suitable printing material preparations, best printing practice regarding PP, and a first testing approach of the mechanical implant performance are addressed. Results indicate that PP implants are accurately printable and seem to be mechanical usable for cranial bone substitution. Further investigations concerning impact behavior and medical applicability will be conducted.

Морфологические особенности парапротезной капсулы при имплантации полипропиленового и композиционного эндопротезов на фоне применения оротовой кислоты в эксперименте

Морфологические особенности парапротезной капсулы при имплантации полипропиленового и композиционного эндопротезов на фоне применения оротовой кислоты в эксперименте

Sources of Reactive Oxygen and Nitrogen Species in Tissue Microenvironment of Hernioplasty Materials.

Titanium and polypropylene mesh endoprostheses were implanted into the rat abdominal cavity and the populations of cells migrating to their surface were analyzed. On both materials, the cells were presented mainly by macrophages that proliferated, activated, and fused to form multinuclear cells. Contact with the foreign surface triggered superoxide anion generation and myeloperoxidase synthesis by macrophages (these processes were more intense on polypropylene implants than on titanium ones) and stimulated production of nitric oxide by macrophage. It was hypothesized that the effects of free nitrogen and oxygen radicals lead to oxidation and destruction of the polypropylene endoprosthesis surface.

CHANGES IN THE QUALITY OF LIFE AND SEXUAL FUNCTION IN WOMEN WITH PELVIC PROLAPSE AFTER LIGATION OF COLPOPEXY WITH POLYPROPYLENE MESH

Objective. To evaluate the effect of vaginal operations to eliminate pelvic prolapse using polypropylene implants on quality of life and sexual function of patients. Materials and methods. The study included 93 women with genital prolapse II - IV stage, underwent extraperitoneal colpopexy polypropylene implant. The patients were divided into two groups according to the method of vaginal ligation of colpopexy: in group 1 (n = 50) included patients who underwent the surgery perforated polypropylene implant Cineplex (LINTEX, Russia) according to the developed method (patent RF № 2538796); 2 (n = 43) group included patients who had an operation using standard kits with polypropylene mesh (ProliftTM, Prolift™ + M, ProsimaTM ETHICON Women's Health & Urology Johnson & Johnson Company, USA). The quality of social and sexual life was assessed using the questionnaire to calculate the index of sexual function in women (Female Sexual Function Index (FSFI)) and non-specific questionnaire of quality of life SF-36 preoperatively and 6 months after. Results . In patients prior to surgical intervention compared with the general population indicators of quality of life statistically significantly reduced for all scales. Physical health component (PHC) reduced by 57.8% in the 1st group and 59.5 per cent in the 2nd group, and psychological health (PsCH) by 42% and 43.5% respectively groups compared with the general population indicators. In the postoperative period, significant improvement in the quality of life in the 2 treatment groups compared with preoperative observed in all parameters. In group 1 noted that PHC restored by 32%, and PsCH 40.7%; in the 2nd group - PHC improved by 26.1% and PsCH of 29.4% (Fig. 2). Comparative analysis of the quality of life of patients after surgery compared groups showed that in group 1 was able to significantly (p<0.05) improve social functioning and mental health patients in comparison with group 2. The total score of the index of sexual function after surgery was significantly increased in the 1st group from 15.8 ± 5.3 to 25.2 ± 4,2; in the 2nd group - from 15.5 ± 5 to 21.4 ± 6. Intergroup statistical analysis of the index of female sexual function after surgical treatment of pelvic prolapse showed significant improvement (p<0.05) in the 1st group for all indicators (desire, arousal, lubrication, orgasm, satisfaction and total score), in addition to the indicator dyspareunia, in comparison with patients of the 2nd group. Conclusions . The pelvic organ prolapse in women significantly affects their quality of life and becomes the cause of sexual disorders. Vaginal reconstruction of pelvic prolapse using polypropylene implants in sexually active women leads to better sexual function by eliminating the loss of the walls of the vagina and urinary incontinence. However, the peculiarities of surgical intervention are responsible for the reduced orgasmic function and appearance of dyspareunia. In patients after vaginal ligation of colpopexy using perforated polypropylene implant according to the developed method was significantly improved sexual function in all indicators of the FSFI questionnaire in comparison with the patients operated using a standard set with polypropylene implant for the correction of pelvic prolapse.

Host reaction to vaginally inserted collagen containing polypropylene implants in sheep

We aimed to characterize the effect of vaginal or abdominal mesh insertion and of different collagen augmentation of polypropylene mesh in a sheep model. Outcome measures were passive and active biomechanical properties and semiquantitative morphometry. Forty-two Texel sheep were used: 6 were nonimplanted controls (n= 6), the rest were implanted with polypropylene mesh (n= 12; Avaulta Solo; Bard Medical, Covington, GA) or collagen-coated meshes: Avaulta Plus (n= 12; Bard Medical) and Ugytex (n= 12; Sofradim International, Trevoux, France). Through a single incision, the rectovaginal septum was dissected and a 35× 35-mm mesh was sutured to the underlying tissues. Abdominally, a 50× 50-mm mesh was laid over a primarily sutured full thickness 40-mm longitudinal incisional defect. Animals were explanted after 60 or 180 days (n= 6 per group). Outcome measures were passive biomechanics by biaxial tensiometry, active contractility of vaginal explants, and histologic evidence. Vaginal explants were 2.4 times stiffer compared with native vaginal tissue (P < .001), but without differences in comfort zone stiffness or slope of the load-elongation in the physiologic range between the products that were tested. Collagen coating was associated with a 16-fold reduction in contractile force at 180 days, compared with native vaginal tissue, both for Avaulta Plus (P= .032) and Ugytex (P= .015). Abdominal explants were 1.3-times stiffer compared with native abdominal wall tissue (P < .001) and were 1.9-times stiffer compared with vaginal explants. Vaginal mesh implantation yields less stiff explants compared with abdominal explants. Vaginal mesh implantation also alters the passive and active biomechanical properties compared with native vaginal tissues. Collagen matrices did not reduce the number of graft-related complications.

Polypropylene mesh: evidence for lack of carcinogenicity

Tumors related to the implantation of surgical grade polypropylene in humans have never been reported. In this commentary we present a balanced review of the information on what is known regarding the host response to polypropylene and provide data as to why the potential for carcinogenicity of polypropylene mesh is exceedingly small.

Highly purified collagen coating enhances tissue adherence and integration properties of monofilament polypropylene meshes

Complications related to tissue integration of polypropylene implants used in the treatment of pelvic organ prolapse are relatively prevalent. Collagen, a biocompatible, less immunogenic material with modulating properties on the inflammatory process, may improve polypropylene integration. The objective was to study biomechanical and histological effects of monofilament polypropylene mesh coated with purified collagen gel. Forty rats were implanted with two fragments of polypropylene mesh in their abdominal walls (one on each side of the linea alba). One of the fragments had a collagen gel coating (group I) while the other one did not (group II). The animals were euthanized at 7, 14, 90, and 180 days after implantation and their abdominal walls were excised for analysis. The biomechanical study showed that mesh adherence to neighboring tissue increased significantly in group II (p < 0.05). Acute (p < 0.001) and chronic (p = 0.004) inflammatory responses as well as granulation tissue formation (p = 0.001) were less intense in group II at 7 and 14 days. Granulomatous inflammation and foreign body reaction was less significant at 7 days in group II (p = 0.029 and p < 0.001). The birefringence analysis showed higher mean brightness density in the late phase of implantation in group II meshes (p = 0.000). Polypropylene mesh coated with purified collagen gel increases adherence to tissue, promotes a less intense and lasting inflammatory response and triggers a greater organization and packing arrangement of collagen fibers in the late phase of implantation.

Five-year results of a randomised controlled multi-centre study comparing heavy-weight knitted versus low-weight, non-woven polypropylene implants in Lichtenstein hernioplasty

BackgroundThis prospective randomised study evaluated whether non-knitted and non-woven lightweight implants can influence postoperative pain and time of return to normal activity, without increasing the recurrence rate in Lichtenstein inguinal hernioplasty.MethodsPatients were operated on in four centres, randomised blindly into two groups with respect to the mesh used: Surgimesh WN (non-woven polypropylene microfibre sheet) and heavy weight polypropylene mesh. The operation was performed according to the Lichtenstein technique. Follow-up was designed for 7 days, and 3, 6, 12 and 60 months. The objectives were to assess the incidence of early and late complications, recurrence rate, and postoperative pain.ResultsA total of 220 patients were randomised; after monitoring visits (exclusion of one hospital), 202 qualified for the assessment. At 60 months, the recurrence rate did not differ statistically. Less pain on the 7th postoperative day, and at 3 months, was observed in the WN group. No other differences were observed.ConclusionsUse of a lightweight non-woven polypropylene implant is a valuable alternative to the use of knitted or woven meshes in the Lichtenstein method. Postoperative pain and recurrence were reduced at short term follow-up, but no statistical difference in recurrence rate was observed at 12 and 60 month follow-up in the patient population tested.

In vitro and in vivo assessment of silver-coated polypropylene mesh to prevent infection in a rat model

The purpose of this study is to determine the effect of silver coating of polypropylene implants on infection in hernia surgery. Silver-coated and non-silver-coated large pore monofilament polypropylene mesh implants were compared with and without infection (four groups). The implants were inserted in the abdominal wall of female Wistar rats. An Escherichia coli strain was inoculated intraoperatively in the two infected groups. The implants were removed, and clinical, bacteriological, and histological analyses were performed at 2, 15, and 30 days postoperatively. Eighty-four rats were studied. All inoculated rats (n = 21) in the non-silver-coated polypropylene group presented periprosthetic E. coli infection, compared with only five inoculated rats in the silver-coated polypropylene group (p < 0.0001). Erosion was significantly higher in the infected than in the non-infected silver-coated polypropylene groups (p < 0.01). There was no histological difference between the four groups. Silver-coated implants appear effective against bacterial infection in our rat model, with good histological tolerance but delayed healing.

Anatomic study of prolapse surgery with nonanchored mesh and a vaginal support device

The purpose of this study was to evaluate the anatomic position and relations to neighboring neurovascular structures of polypropylene implants after vaginal repair with nonanchored mesh and a vaginal support device in a cadaver model. We undertook anatomic dissection of 6 cadavers, with and without prolapse after surgery. All polypropylene implants were positioned in accordance with the prescribed surgical technique. This surgery reconstructed the entire anterior and posterior pelvic floor compartments without extension beyond the pelvic cavity. A safe distance between the implants and their neighboring neurovascular structures (obturator nerve and vessels, 2.8-3.3 cm; pudendal nerve and internal pudendal vessels, 1.8-2.2 cm; sacral plexus, 2-2.2 cm) was observed. Anatomic cadaver dissection confirmed the accurate and safe placement of the polypropylene implants with the use of the prescribed surgical technique.

Implante sintético como estabilizador articular, após desmotomia dos ligamentos cruzados de cães: proposição de técnica

A ruptura do ligamento cruzado (LC) é uma enfermidade diagnosticada em grande parte dos cães com problemas articulares, sendo a causa mais comum de afecção articular degenerativa da articulação do joelho. Este trabalho objetivou avaliar clinicamente a ação da malha de polipropileno como único substituto do LC cranial e caudal de cães, ressaltando particularidades da técnica aqui proposta. Foram utilizados 20 cães, submetidos à desmotomia unilateral dos LC cranial e caudal. Vinte e um dias após a ruptura, todos foram tratados cirurgicamente pela técnica de redução aberta, com o implante de polipropileno substituindo apenas o LC cranial. A técnica proposta demonstrou rápida execução e pouca dissecação de tecidos moles, retorno precoce à deambulação, resistência adequada do implante sem associação de imobilização externa e ausência de reação articular até os 90 dias de pós-operatório.

Ischiasneuropathie nach Beckenbodenrekonstruktion

After the surgical treatment of a recurrent enterocele and rectocele using a polypropylene implant, a patient developed a reversible paralysis. Haematoma was excluded. To search for the cause of the paralysis, polypropylene implants were inserted in four ethanol-preserved cadavers. Their dissection showed a safe distance at all points between the implant and the sciatic nerve. The patient's paralysis was most likely due to the lithotomy position, with an overstretching of the sciatic nerve during the intraoperative flexion of the hip joint.

Evaluation of a new composite prosthesis for the repair of abdominal wall defects

The degree of integration of biomaterials used in the repair of abdominal wall defects seems to depend upon the structure of the prosthesis. The present investigation evaluates the behaviour in terms of adhesion formation and integration of a new composite prosthesis that could be employed in this clinical application. Full-thickness abdominal wall defects (7 x 5 cm) were created in 16 anaesthetized New Zealand white rabbits and the prosthesis were placed in direct contact with the visceral peritoneum during the experiment. The defects were repaired with a composite prosthesis or pure polypropylene mesh to establish two study groups (n = 8 each). The composite device was constituted by a polypropylene mesh physically attached to a poly(ether)urethane-polydimethylsiloxane laminar sheet. Animals were sacrificed 7, 14, 21 and 30 days after implant and prosthesis/surrounding tissue specimens subjected to light and electron microscopy. Firm adhesions were detected in the polypropylene implants, while they were not present in the composite implants. The excellent behaviour of the composite prosthesis shown in this study warrants further investigation on its use for the repair of abdominal wall defects when a prosthetic device needs to be placed in contact with the intestinal loops.

Tensile Strength and Host Response towards Silk and Type I Polypropylene Implants Used for Augmentation of Fascial Repair in a Rat Model

Objective: We compared host response, architectural integration and tensile strength of two different macroporous silk constructs to a polypropylene type I implant in a rat model for augmentation of primary fascial defect repair. Materials and Methods: Animals were sacrificed on days 7, 14, 30 and 90 after implantation. The explants were evaluated macroscopically for infections, herniations and adhesions, mechanically for tensile strength, and histopathologically, to evaluate collagen deposition and inflammatory response. Results: The tensile strength of the explants showed a gradual increase for all materials. All implants uniformly shrank around one fifth by 90 days. In the silk implants, the inflammatory reaction showed a remarkable higher number of foreign body giant cells that characteristically spread from the periphery into implants. Collagen deposition was comparable for all the materials. In Silk a higher grade of neovascularisation was observed. Conclusion: Silk explants expressed high tensiometric strength, which was associated with a marked fibrotic process. The silk implants induced a strong foreign body reaction accompanied by microscopic signs of architectural degradation at 90 days. Polypropylene explants showed a more moderate foreign body reaction without architectural disturbance.

Anatomical conditions for pelvic floor reconstruction with polypropylene implant and its application for the treatment of vaginal prolapse

Objective The purpose of the surgical treatment of vaginal prolapse is not only the restoration of the anatomy but also of the visceral functioning. To maintain the quality of life for patients with recurrent vaginal prolapse, to reduce the failure rates of operations and to avoid a colpectomy or a colpocleisis at the same time, synthetic materials have been introduced in transvaginal reconstructive surgery of the pelvic floor. The TVM Group from France described the reconstruction of the pelvic floor with polypropylene implants in 2004. The aim of this study is to determine the anatomical position of the polypropylene implants after reconstruction of each compartment of the pelvic floor and to determine the relation of the implants to the major neighbouring neurovascular structures on the basis of corpse dissections. Study design Following the technique of the TVM Group from France we present the pelvic floor reconstruction using Gynecare Prolift* (Ethicon, Sommerville, NJ, USA). To reach the aims of the study, anatomical dissections of the pelvic floor on three specially preserved anatomical specimens are performed after the placement of the implants. Results The anatomical dissections show that every defect in all three compartments of the pelvic floor can be repaired by using polypropylene implants. Between the implants and the major neighbouring neurovascular structures a safe distance exists with slight individual differences. Conclusion The pelvic floor reconstruction using polypropylene implants is a treatment option especially for the surgical correction of the recurrent vaginal prolapse. If the surgeon has thorough anatomical knowledge and performs the surgical technique in the recommended manner, injuries of the major neighbouring neurovascular structures will be avoided. Clinical studies will analyze the long-term results after pelvic floor reconstruction using polypropylene implants.