Polytetrafluoroethylene Implants Research Articles

M-Shaped Auricular Cartilage Grafts for Correcting Short Nose Deformity in Asians: A Retrospective Study.

The demand for rhinoplasty in Asia is growing annually, and short nose deformity has been one of the main reasons for the surgery due to its high incidence. There is an urgent need for rhinoplasty suitable for Asians because of their different facial features from Westerners. The M-shaped auricular cartilage rhinoplasty has been developed as a new method for correcting short nose deformity for Asians. This study aimed to evaluate the aesthetic and functional results of M-shaped auricular cartilage rhinoplasty compared to clinically commonly used rhinoplasty methods. A total of 45 patients were enrolled and divided into three groups of 15 patients: The first group underwent M-shaped auricular cartilage rhinoplasty, the second group underwent auricular-septal cartilagerhinoplasty, and the third group underwent overlapped auricular cartilagerhinoplasty. All of these patients underwent comprehensive rhinoplasty and had silicone or expanded polytetrafluoroethylene implants in the dorsum of their noses. The patient score improvements on the three patient-reported outcome measures were higher in the M-shaped auricular cartilagerhinoplasty group (1.65/1.79/0.11) compared with the overlapped auricular cartilagerhinoplasty group (1.40/1.51/0.05), and the score improvements in the auricular-septal cartilagerhinoplasty group (2.04/1.98/0.28) were the highest. This is a retrospective clinical study demonstrating the clinical efficacy of M-shaped auricular cartilage rhinoplasty. Compared with the overlapped auricular cartilage rhinoplasty, the effect of this novel M-shaped method is better. However, when compared to the auricular-septal cartilage rhinoplasty with septal extension and reinforcement using nasal septal cartilage, its effect is slightly worse. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Комбинированный способ хирургического лечения при паралитическом лагофтальме с применением имплантатов из политетрафторэтилена

The purpose is to develop a combined method of paralytic lagophthalmos treatment using polytetrafluoroethylene (PTFE) implants. Material and methods. The clinical group consisted of 20 patients (8 males, 12 females) aged 31-69 (44.7 ± 5.3 years) with facial nerve paralysis, who were treated within the last 3 years. The onset of paralytic lagophthalmos took place 1-9 years (3.3 ± 2.1 years) before surgical treatment. A typical clinical picture was as follows: lagophthalmos 9-16 mm (13.3 ± 3.1 mm), retraction of the upper eyelid 3-6 mm (4.1 ± 1.1 mm), atony and ectropion of the lower eyelid, epitheliopathy (11 cases), leucoma (9 cases). Visual acuity was 0.01-1.0 (0.3 ± 0.15). All patients had surgery for lagophthalmos with the use of a PTFE implant. In 5 patients, surgery was performed in two stages (separately for the upper and the lower eyelids), in 15 cases it was performed simultaneously, using a combined method The implant was a porous PTFE tape 200-300 μm thick, either solid or with perforations. The follow-up period was 6 months to 3 years (1.9 ± 0.9 years). Results. No complications have been revealed either in the early or late follow-up periods. All patients had positive dynamics of the following parameters: the size of lagophthalmos, the presence of ectropion of the lower eyelid, retraction of the upper eyelid, the condition of the cornea. The evaluation was conducted 6 months after surgery or later. In all cases, lagophthalmos decreased significantly, the residual lagophthalmos was 2-5 mm (3.1 ± 1.3 mm). The condition of the cornea in patients with keratopathy improved, vision increased to reach 0.1 1.0 (0.5 ± 0.25). Conclusion. In the proposed method, the lagophthalmos is eliminated by lower eyelid strengthening and upper eyelid recession. PTFE implants provide a stable effect. For citation: Filatova I.A., Shemetov S.A. Combined method of surgical treatment for paralytic lagophthalmos with polytetrafluoroethylene (PTFE) implants. Russian ophthalmological journal. 2018; 11 (2): 27-34. doi: 10.21516/2072-0076-2018-11-2-27-34 (In Russian).

Perioperative warming, oxygen, and Ilomedin on oxygenation and healing in infrainguinal bypass surgery

BackgroundPerioperative adjuncts are utilized across surgical specialities with the goal of improving patient outcomes. High-dose oxygen and extended warming are shown to increase wound collagen deposition during abdominal surgery. Prostacyclin is shown to improve limb salvage and patency rate in infrainguinal bypass (IIB) surgery. This study evaluated the impact of these adjuncts on healing and perfusion post IIB surgery. MethodsThis randomized controlled study allocated patients undergoing IIB surgery into three treatment arms (perioperative high-dose oxygen, extended warming, and a synthetic prostacyclin) or a control group. The primary outcome was accumulation of hydroxyproline (OHP, collagen surrogate marker) as collected in polytetrafluoroethylene implants on day 5. Secondary outcomes included levels of growth factors and cytokines, and tissue oxygenation of the wound and foot as measured by hyperspectral technology and ankle-brachial pressure index. Clinical outcomes were observed to day 30, with long-term follow-up of 12 mo. ResultsSeventy-one patients completed the study. Comparing treatment groups with the control at day 5, there were no differences in OHP, growth factors or cytokines levels, or improvement in tissue oxygenation at the surgical incision. However, there was more flow to the foot (HT-SUM (%) change) in the Ilomedin group compared to control (0% versus −14.6%, P = 0.045). HT-deoxy was higher at the peripheries in the oxygen and temperature groups, suggesting decreased tissue oxygenation. ConclusionsThe perioperative treatments did not dramatically improve oxygenation or healing of the surgical wound in IIB surgery; however, Ilomedin may result in greater flow to the peripheries.

Safety and Efficacy of Expanded Polytetrafluoroethylene Implants in the Surgical Management of Traumatic Nasal Deformity.

The ideal alloplastic implant for correction of traumatic nasal deformity has not been adequately examined. To evaluate the safety profile and postoperative results of expanded polytetrafluoroethylene (ePTFE) implants used in functional nasal surgery (FNS) in the setting of traumatic nasal deformity. We conducted a 13-year retrospective medical chart review for patients treated at a tertiary academic facial plastic and reconstructive surgery practice between July 1999 and July 2012. A total of 404 FNS procedures were performed by a single surgeon during this period, 255 to repair traumatic deformities, 35 of these involving ePTFE implants. Patient demographics, medical comorbidities, operative and technical considerations, functional and aesthetic results, complications, and postoperative course findings were collected from patient records. In addition, preoperative and postoperative photographic documents were examined. Functional nasal surgery. Postoperative complications or presentations necessitating revision. A total of 404 patients (197 male, 207 female) underwent FNS. Of those, 255 procedures were to treat traumatic deformities. Forty patients altogether required the use of an ePTFE implant, 35 of those 40 deformities being associated with a traumatic injury. One of the 35 patients in the ePTFE-repaired traumatic deformities group experienced postoperative infection. This patient ultimately developed exposure after the infection failed to resolve with oral antibiotics, and the implant was removed. An additional patient in the ePTFE group required revision of the implant owing to contour irregularity and aesthetic concerns. No infections or other complications occurred among the 220 patients with traumatic deformity treated with autologous grafts. Analysis of other variables including sex, tobacco use, diabetes, immunosuppression, implant thickness, suture material, and prior septorhinoplasty were not associated with increased rate of infection (P > .05 for all). In the setting of traumatic nasal deformities requiring FNS, ePTFE implants can be used at the level of the nasal dorsum, where soft tissue coverage is often adequate, with a low risk of complications.

Safety and Efficacy of Expanded Polytetrafluoroethylene Implants in the Surgical Management of Traumatic Nasal Deformity

Safety and Efficacy of Expanded Polytetrafluoroethylene Implants in the Surgical Management of Traumatic Nasal Deformity

Comparative Study of Morphological and Histological Changes between Differently Structured Expanded Polytetrafluoroethylene Implants in an Animal Model

Expanded polytetrafluoroethylene (e-PTFE) is a popular graft material used in augmentation rhinoplasty. New e-PTFE has thicker fibrils and is more compact than first developed e-PTFE. This study aimed to compare morphological and histological changes between differently structured e-PTFE implants in a rat model. Two types of e-PTFE were implanted in the cranial region of 30 adult male rats. En bloc specimens containing the implants and surrounding soft tissues were sampled 1, 3, and 6 months after implantation. We measured the three-dimensional size of the implants over time and evaluated histological changes using light and electron microscopy. Grossly, no implants were extruded, and there was no evidence of wound infection. All first developed e-PTFE samples were fixed to surrounding tissues after 1 month, whereas new e-PTFE samples tended to migrate and were easily separated from surrounding tissues until 3 months after implantation. The first developed e-PTFE height diminution rate was 14.7% of the initial value after 6 months; however, new e-PTFE size was not changed. Diameter and height diminution rates for first developed e-PTFE were significantly greater than those for new e-PTFE after 6 months. Histologically, connective tissue in growth was observed in first developed e-PTFE after 1 month, and the internodal space decreased over time; however, connective tissue did not infiltrate into new e-PTFE until 6 months and the internodal space was not significantly changed. First developed e-PTFE should be carefully trimmed in augmentation because of its potential to decrease in size over time, whereas new e-PTFE is more likely to show migration and instability.

Complications Associated With Alloplastic Implants in Rhinoplasty

To evaluate the incidence of infection and extrusion of porous high-density polyethylene (pHDPE) and expanded polytetrafluoroethylene (ePTFE) implants used in rhinoplasty at a high-volume, academic facial plastic surgery practice. A total of 662 rhinoplasty procedures performed by 3 faculty surgeons from 1999 to 2008 were retrospectively reviewed. Patient demographics, medical comorbidities, operative details, and postoperative course findings were collected from patient records. The incidence of postoperative infection was 2.8% (19 of 662 patients). In each case of infection, alloplastic material had been used. Infections occurred in 1 in 5 rhinoplasty procedures in which pHDPE implants were used. In patients in whom ePTFE was used alone, the infection rate was 5.3%. Exposure developed in 12% of patients in whom an alloplast was used during surgery. Factors notably not associated with infection on bivariate analysis included sex, surgeon, purpose of procedure (functional vs cosmetic), current tobacco use, or history of cocaine use (P > .05 for all). To our knowledge, this study represents the largest evaluation of the use of pHDPE implants in rhinoplasty to date. Our findings are in contrast to those of previous studies regarding the use of pHDPE in rhinoplasty and parallel to those regarding the use of ePTFE. Caution is strongly recommended when considering the use of pHDPE in rhinoplasty.

Experimental noninferiority trial of synthetic small-caliber biodegradable versus stable vascular grafts

Long-term evolution of polycaprolactone vascular prostheses has been investigated recently. The goal of this study was to evidence a noninferiority of such grafts compared with expanded polytetrafluoroethylene (ePTFE) implants in an aortic replacement model in the rat. Fourteen anesthetized Sprague-Dawley rats received an infrarenal aortic graft (biodegradable, n = 8; expanded polytetrafluoroethylene, n = 6) replacement (end to end; inner diameter, 2 mm). Biodegradable grafts (polycaprolactone) were produced by random micro-/nanofiber electrospinning. After a median survival of 16.5 months, in vivo ultrasonography and angiography as well as postexplantation microcomputed tomography, histomorphometry, immunohistochemistry, and scanning electron microscopy were performed. Patency was 100% for polycaprolactone and 67% for ePTFE. No aneurysmal dilatation or stenoses were found in either group. Compliance was significantly higher for polycaprolactone compared with ePTFE (8.2 ± 1.0%/100 mm Hg vs 5.7 ± 0.7%/100 mm Hg; P < .01), but markedly reduced compared with adjacent native aortas and the control group. Histologically, low cellular in-growth was found in ePTFE whereas polycaprolactone showed significantly greater homogenous cellularity, producing an autologous extracellular matrix (10.8% ± 4.0% vs 32.1% ± 9.2%, P < .0001). Morphometry showed 100% neo-endothelialization for both grafts with a totally confluent endothelial coverage for polycaprolactone grafts by scanning electron microscope. More intimal hyperplasia was found in ePTFE compared with polycaprolactone grafts. Calcification was higher in ePTFE than in polycaprolactone grafts (15.8% vs 7.0%, P = .04) and was absent in controls. Outcomes of synthetic biodegradable nanofiber polycaprolactone grafts are not inferior compared with the clinically used expanded polytetrafluoroethylene grafts after long-term implantation in the rat aorta. Moreover, these implants show better patency, compliance, endothelialization, and cell in-growth, and less intimal hyperplasia and calcification than their counterparts.

The long-term behavior of lightweight and heavyweight meshes used to repair abdominal wall defects is determined by the host tissue repair process provoked by the mesh

Although heavyweight (HW) or lightweight (LW) polypropylene (PP) meshes are widely used for hernia repair, other alternatives have recently appeared. They have the same large-pore structure yet are composed of polytetrafluoroethylene (PTFE). This study compares the long-term (3 and 6 months) behavior of meshes of different pore size (HW compared with LW) and composition (PP compared with PTFE). Partial defects were created in the lateral wall of the abdomen in New Zealand White rabbits and then repaired by the use of a HW or LW PP mesh or a new monofilament, large-pore PTFE mesh (Infinit). At 90 and 180 days after implantation, tissue incorporation, gene and protein expression of neocollagens (reverse transcription-polymerase chain reaction/immunofluorescence), macrophage response (immunohistochemistry), and biomechanical strength were determined. Shrinkage was measured at 90 days. All three meshes induced good host tissue ingrowth, yet the macrophage response was significantly greater in the PTFE implants (P < .05). Collagen 1/3 mRNA levels failed to vary at 90 days yet in the longer term, the LW meshes showed the reduced genetic expression of both collagens (P < .05) accompanied by increased neocollagen deposition, indicating more efficient mRNA translation. After 90-180 days of implant, tensile strengths and elastic modulus values were similar for all 3implants (P > .05). Host collagen deposition is mesh pore size dependent whereas the macrophage response induced is composition dependent with a greater response shown by PTFE. In the long term, macroporous meshes show comparable biomechanical behavior regardless of their pore size or composition.

Modification of polytetrafluoroethylene implants by depositing TiCaPCON films with and without stem cells

The present work is focused on the investigation of the structure and properties of TiCaPCON films deposited on the surface of polytetrafluoroethylene (PTFE) as potential bio-implant material. The films were deposited by DC magnetron sputtering of composite TiC 0.5 + Ca 3(PO 4) 2 target produced by self-propagating high-temperature synthesis (SHS). The film structure was examined using X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The films were also characterized in terms of their adhesion to the PTFE substrate, hardness, elastic modulus, elastic recovery, wettability, and friction coefficient both in physiological solution (normal saline) and Dulbecko modified Eagle medium with fetal calf serum. The biological properties of the films were evaluated by in vitro and in vivo experiments. In vitro studies showed that human fibroblasts well adhered and spread on the surface of the PTFE sample coated with TiCaPCON films. In vivo studies using rat hip and rabbit calvarial defect models demonstrated a high osseointegration potential of the TiCaPCON/PTFE implants. In vivo bone tissue regeneration using hybrid implants (adipose-derived stem cells/TiCaPCON film/PTFE porous membrane) were also reported.

Expanded Polytetrafluoroethylene as Dorsal Augmentation Material in Rhinoplasty on Southeast Asian Noses

Objective To describe the outcomes of dorsal augmentation rhinoplasty with expanded polytetrafluoroethylene (ePTFE) implants in Southeast Asian patients from the Philippines. Methods Retrospective ...

Expanded Polytetrafluoroethylene as Dorsal Augmentation Material in Rhinoplasty on Southeast Asian Noses

To describe the outcomes of dorsal augmentation rhinoplasty with expanded polytetrafluoroethylene (ePTFE) implants in Southeast Asian patients from the Philippines. Retrospective review of 1054 patients. Of the 1054 patients, 90.61% were women and 9.39% were men. One thousand eight patients (95.64%) underwent primary rhinoplasty; 46 (4.36%), secondary or revision rhinoplasty. One thousand thirty (97.72%) had desirable and 24 (2.28%) had undesirable outcomes. The most common undesirable outcome was implant deviation (1.04%), followed by a visible ePTFE implant (0.47%). Implant infection occurred in 0.38% of the patients, and 0.38% of the patients were not satisfied with their aesthetic outcome because of the presence of a high nasal bridge. We find ePTFE to be an excellent synthetic material with proven outcomes for augmenting the dorsum in rhinoplasty of the Southeast Asian patient. However, prudent use of this material is warranted to avoid undesirable outcomes.

Gore-Tex Nasal Augmentation

Gore-Tex Nasal Augmentation

Are Polytetrafluoroethylene (Gore-Tex) Implants an Alternative Material for Nasal Dorsal Augmentation in Asians?

Augmentation rhinoplasty is a relatively common procedure in Korea. Alloplastic materials such as silicone, supramid mesh, Proplast, Mersiline, Medpor, and hydroxyapatite are frequently used for dorsal augmentation. Alloplastic implants have advantages, such as ready availability and no donor-site morbidity, but are associated with higher infection and extrusion rates than are autogenous materials. Although polytetrafluoroethylene (Gore-Tex) implants have recently been introduced, such implants are yet to be established as an alternative for nasal augmentation because of a lack of relevant reports. From March 1998 to March 2007, we operated on 873 nasal dorsum augmentation patients using hard-type Gore-Tex implants. The patients were all of Korean ethnicity. There were 826 female and 47 male patients and aged ranging from 18 to 57 years (mean, 24 y). The Gore-Tex implant thicknesses were 3.1 to 4.9 mm (used in 59% of cases), 2 to 3 mm (8%), or 5 to 6 mm (33%). The Gore-Tex implants were used only for dorsal augmentation, whereas conchal or septal cartilage was used for nasal tip plasty. Of the total of 873 patients, 257 received long-term follow-up (mean follow-up, 34 mo). Apart from 34 patients with revision, no patient reported dissatisfaction, and there were no reports of problems with nasal contour, implant migration, or resorption of the implant material. The overall complication rate was 3.8%. Of the 257 long-term follow-up patients, 34 (13.5%) required revision. Four of these patients involved minor complications that were managed conservatively, whereas 30 patients required implant removal and revision procedures. These 30 cases included irregularity, infection, deviation, unfavorable dorsum height, and apparent implant silhouette, in addition to obvious supratip deformity. A review of the literature revealed that Gore-Tex implants seemed to have a lower implant removal rate than silicone implants. However, the overall complication rates seemed to be similar when Gore-Tex and silicone implants were used for nasal dorsum augmentation in Asian patients. We found that Gore-Tex implants were effective and safe for use in primary and revision rhinoplasty in Asians. Gore-Tex implants seem to have an overall complication rate similar to that of silicone implants. Thus, Gore-Tex can be considered as an alternative material for dorsal augmentation rhinoplasty but turned out not to have definite advantages over the silicone implants.

Enhancement of capillary and cellular ingrowth in ePTFE implants with a proangiogenic recombinant construct derived from fibronectin

Based on our discoveries of a unique, synergistic interplay between vascular endothelial growth factor (VEGF) and specific domains of the matrix protein fibronectin (FN), we used recombinant technology to create a new protein construct derived from the cell-binding and VEGF-binding domains of FN. We wished to test the hypothesis that this prototype recombinant FN (rFN) protein would enhance cellular and capillary ingrowth in vivo into expanded polytetrafluoroethylene (ePTFE) implants. ePTFE disks of high porosity (60 micron internodal distance) were embedded with fibrin gel and heparin, with/without mixtures of VEGF and rFN and were implanted subcutaneously in rats. Control implants embedded with fibrin glue and heparin alone showed an average of 8.5% (±0.51% standard error mean (SEM)) cellular ingrowth. The addition of either VEGF or rFN caused a modest but significant increase in cellular ingrowth (12.7 ± 1% and 11.8 ± 0.98%, respectively, p < 0.004). However, the combination of rFN/VEGF/heparin dramatically increased cellular ingrowth (27.6 ± 1.62%, p < 0.001), compared with all other treatments. Quantification of capillary ingrowth yielded the same pattern. These results suggest that the incorporation of such biological modulators into cardiovascular implants could offer new strategies for the design of a ready-made small diameter prosthetic graft with enhanced capacity for neovascularization and endothelialization.

Current Status of Grafts and Implants in Rhinoplasty: Part II. Homologous Grafts and Allogenic Implants

After reading this article, the participant should be able to: 1. Understand the challenges in restoring volume and structural integrity in rhinoplasty. 2. Identify the appropriate uses of various homologous grafts and allogenic implants in reconstruction, including: (a) freeze-dried acellular allogenic cadaveric dermis grafts, (b) irradiated cartilage grafts, (c) hydroxyapatite mineral matrix, (d) silicone implants, (e) high-density polyethylene implants, (f) polytetrafluoroethylene implants, and (g) injectable filler materials. 3. Identify the advantages and disadvantages of each of these biomaterials. 4. Understand the specific techniques that may aid in the use these grafts or implants. This review specifically addresses the use of homologous grafts and allogenic implants in rhinoplasty. It is important to stress that autologous materials remain the preferred graft material for use in rhinoplasty, owing to their high biocompatibility and low risk of infection and extrusion. However, concerns of donor-site morbidity, graft availability, and graft resorption have motivated the development and use of homologous and allogenic implants.

Expanded Polytetrafluoroethylene Implants for Soft-Tissue Augmentation: 5-Year Follow-up and Literature Review

Expanded polytetrafluoroethylene implants have been used successfully for augmentation of thinning lips, deep nasolabial folds, and marionette lines without the risk, recovery time, and expense of major surgery. The objective was to assess long-term results and patient satisfaction with expanded polytetrafluoroethylene implants. A retrospective chart review was performed on all patients treated with expanded polytetrafluoroethylene implants from January 1, 2001, to July 1, 2002. Eighty-five implants were placed in 33 patients. Forty-six percent of implants were placed in the nasolabial folds, 34% in the lips, 16.5% in the marionette lines, 2% in the oral commisures, and 1% in the glabella. Eighty-seven percent of implants remain in place with excellent correction. Eleven implants in 6 patients were removed. Four of the 11 implants removed were considered too small by the patient and were replaced with larger implants without difficulty. The other reasons for implant removal included malposition, localized swelling, and an unnatural feel. Patient and physician satisfaction with the treatment was high. Expanded polytetrafluoroethylene implants are a safe, effective, and permanent option for facial volume augmentation. Patients who have had their implants in place for 5 years or more continue to report high satisfaction with the treatment. The authors have indicated no significant interest with commercial supporters.

EPTFE implants for hypoplastic lips in cleft lip and palate patients

Objective: This study was conducted to assess the functional and cosmetic outcome of expanded polytetrafluoroethylene (ePTFE) implants for hypoplastic lips in operated cleft lips and palate patients. Methods: ePTFE implants were placed in 15 patients with hypoplastic upper lips following repair of cleft lip and palate. These patients were assessed post-operatively for functional and cosmetic acceptance and complication. Results: Cosmetic and functional results were extremely satisfactory for all the patients. Postoperative infections occurred in two patients warranting removal of implants. Conclusion: ePTFE lip implants are an excellent option for hypoplastic lips but further long-term evaluation is required.

Prevención de adherencias peritoneales a las prótesis intraperitoneales. Estudio experimental en cerdos

The aim of this study was to investigate the effect of fibrin glue and hyaluronidase gel on the prevention of postoperative peritoneal adhesions to intraperitoneal prostheses. Twenty pigs, divided in two groups, were included. In all animals, four implants (4 x 4 cm) were placed: two polypropylene mesh implants were placed in an upper location and two polytetrafluoroethylene (PTFE) implants (Dualmesh Plus Corduroy) were placed in a lower position. Implants located in the right side of the animals were painted with fibrin glue (group A, n = 10) or with hyaluronidase gel (group B, n = 10). After 5 weeks, the animals were sacrificed and the results (number and grade of intraperitoneal adhesions, histological data on prosthesis integration, such as mesothelialization, fibroblast infiltration, vessel neoformation, etc.) were evaluated. Intraperitoneal adhesions decreased in implants painted with fibrin glue and hyaluronidase gel compared with untreated implants. When right-sided adhesions formed, they were looser and in many animals, the implants were completely peritonized. Integration of the prostheses was not affected by either fibrin glue or hyaluronidase gel. Adhesion formation can be reduced after abdominal surgery. The reduction achieved in this study was greater in the quantity than in the consistency of the adhesions. The results with hyaluronidase gel were moderately superior to those obtained with fibrin glue. Hyaluronidase gel has the advantage of being inexpensive.

Tissue integration and biomechanical behaviour of contaminated experimental polypropylene and expanded polytetrafluoroethylene implants.

Infection is one of the most devastating complications following implantation of a prosthetic material. The aim of this study was to compare the behaviour of two biomaterials contaminated with Staphylococcus aureus or Staphylococcus epidermidis, used to repair abdominal wall defects. Defects (7 x 5 cm) were created in the anterior abdominal wall of 60 white New Zealand rabbits and repaired using polypropylene or expanded polytetrafluoroethylene (ePTFE) prostheses. The site of repair had been previously inoculated with 10(6) colony-forming units/ml S. aureus or S. epidermidis. Seven and 30 days after implantation, prosthetic specimens were examined by light and scanning electron microscopy, and immunohistochemical and biomechanical analysis. No significant differences with respect to controls were observed in the S. epidermidis groups. Two animals inoculated with S. aureus died. S. aureus induced the appearance of denuded areas exposing the filaments in the polypropylene prostheses, whereas the ePTFE prostheses showed zones of erosion, disorganized tissue, haemorrhage and necrosis. The biomechanical strength of the contaminated implants was unaltered. Integration within host tissue was affected in the setting of S. aureus infection but the tensile strength of contaminated prostheses was not significantly reduced.