Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Polypropylenes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed2006

[Transvaginal cervico-isthmic cerclage using polypropylene tape: surgical procedure and pregnancy outcome: Fernandez's procedure].

OBJECTIVE: To assess the efficacy of performing transvaginal cervico-isthmic cerclage using synthetic tape in prevention of preterm labor in high-risk women. PATIENTS AND METHODS: A retrospective analysis of 24 transvaginal cerclages using polypropylene tape performed in women presenting with high risk of preterm delivery: prior histories of pregnancy losses in the second trimester, prior failure of Mac Donald's cerclage and/or absent portio vaginalis of the cervix. Cerclage was performed between 12 and 16 weeks of gestation. A polypropylene tape was placed at the cervicoisthmic junction by vaginal route. RESULTS: The median age of the patients in this series was 32.1 years (range 22-39 years). No intra-operative complication occurred. The median operating time was 34.9 minutes (+/-5.1) (range 30-45 min). Cesarean delivery was systematically performed in all patients since the cerclage was considered to be definitive. Mean gestational age and birth weight at delivery were respectively 37.1 weeks (+/-1.8) and 2850 g (+/-745). Preterm birth rate was 19% (4/21). Birth at less than 32 weeks occurred in only one patient (4%). In one case, the tape has been removed later because symptomatic vaginal erosion was noted. One neonatal death occurred following amniotic fluid infection at 34 weeks. At the present time, 3 women are at 22, 26 and 26 weeks of gestation with no preterm labor. CONCLUSION: Transvaginal cerclage using polypropylene tape may be considered as an effective and minimally invasive alternative to transabdominal cervico-isthmic cerclage in women presenting with high risk of preterm delivery.

Adult↗
PubMed1999

A multivariate method to predict the water vapour diffusion rate through polypropylene packaging.

Semipermeable containers typically allow water to diffuse upon storage. The water diffusion rate of the widely distributed X-ray contrast agent Visipaque in polypropylene bottles and MR contrast agent Omniscan in polypropylene syringes has been evaluated. The goal was to develop a mathematical method for estimating the rate constant for water diffusion through the polypropylene wall as a function of several variables. The method presents an opportunity to measure the effect of the variables influencing product stability and thereby predicting the shelf-life at an early stage of the stability study. The effect of temperature, humidity, surface area, wall thickness, concentration of active ingredient and fill volume on the logarithmic rate constant for diffusion was estimated by partial least squares regression. The predictive ability of the cross-validated models was good (r = 0.99) for the two contrast agents. The models were used to predict shelf-life for relevant combinations of temperature and humidity, for the four defined climatic zones.

Contrast Media↗
PubMed1999

Effect of relaparotomy through previously integrated polypropylene and polytetrafluoroethylene experimental implants in the abdominal wall.

BACKGROUND: The appearance of new pathologies affecting abdominal organs after implant of a prosthesis to repair an abdominal wall defect may necessitate reintervention. The aim of this study was to compare the behavior of two types of biomaterial widely used in clinical practice, polypropylene (PL) and polytetrafluoroethylene (ePTFE), after a second laparotomy involving the implant. The behavior, in terms of tensile resistance and integration with tissues, of intact prostheses was compared to that of prostheses subjected to opening and repair. METHODS: A defect (7x5 cm) involving all tissue layers was created in the anterior abdominal wall of 24 male New Zealand rabbits. These defects were repaired with a reticular, macroporous PL mesh (Marlex, Bard Card., Madrid, Spain) or a laminar, micro/macroporous ePTFE prosthesis (Mycro Mesh, W.L. Gore, Flagstaff, AZ) of similar size to the defect. Four study groups were established: Intact PL/Intact ePTFE (n = 6 each): animals implanted with a PL or ePTFE prosthesis and sacrificed 90 days after implant; Repaired PL/Repaired ePTFE (n = 6 each): animals implanted with a PL or ePTFE prosthesis subjected to midlongitudinal relaparotomy through the center of the prosthesis 90 days postimplant, followed by repair with continuous polypropylene 4/0 suture. Animals in repaired groups were sacrificed 90 days after the second intervention. Specimens comprised of prosthesis and neoformed tissue were subjected to light and scanning electron microscopy. In addition, 2 cm-wide strips, consisting of the prosthesis and anchorage tissue, were subjected to biomechanical analysis using an Instron tensiometer (Instron, Canton, MA). The results obtained were statistically compared using the Mann-Whitney U-test. RESULTS: The intact PL implants were fully infiltrated by dense, disorganized, well-vascularized scar tissue with fibers concentric to the mesh monofilaments. The appearance of the repaired PL prostheses was similar, with establishment of neoformed tissue in repaired areas of the prosthesis such that both cut edges of the prosthesis were joined together. In contrast, intact ePTFE prostheses were encapsulated by organized tissue with fibers running parallel to the surface of the biomaterial. Repaired ePTFE prostheses including sutured areas were similarly encapsulated. But the edges of the sutured middle area did not fuse. Tensile resistance values of intact and repaired PL prostheses were similar (intact, mean, 34.78 Newtons; repaired, mean, 34.74N, p>0.001). Tensile resistance values of intact ePTFE implants were significantly different to those of the repaired ePTFE prostheses (intact, mean, 22.64N; repaired, mean, 17.21N, p<0.001). Breakage of both types of PL specimen strips was restricted to recipient tissue while breakage of intact ePTFE specimens occurred in the areas of anchorage to the abdominal wall. Rupture of repaired ePTFE specimens took place in the sutured central areas of the prostheses. CONCLUSIONS: We conclude that relaparotomy through an existing PL prosthesis previously integrated with the abdominal wall does not affect the tissue integration process or the tensile resistance of the implant. When the relaparotomy involves an ePTFE prosthesis, however, although the repair process itself is unaffected, significant loss in tensile strength is incurred. In addition, relaparotomy through both types of biomaterial is likely to result in the neoformation of adhesions in the areas of the prosthesis subjected to opening and repair but, in general, the number of adhesions formed in the presence of intact or repaired polypropylene implants was larger than that observed with the use of ePTFE.

Abdominal Muscles↗
PubMedDate not supplied

New nanocomposite materials reinforced with cellulose whiskers in atactic polypropylene: effect of surface and dispersion characteristics.

New nanocomposite films were prepared with atactic polypropylene as the matrix and either of three types of cellulose whiskers, with various surface and dispersion characteristics, as the reinforcing phase: aggregated without surface modification, aggregated and grafted with maleated polypropylene or individualized and finely dispersed with a surfactant. Films obtained by solvent casting from toluene were investigated by means of scanning electron microscopy, dynamic mechanical analysis, and tensile testing. In the linear region, the mechanical properties above the glass-rubber transition were found to be drastically enhanced for the nanocomposites as compared to the neat polypropylene matrix. These effects were ascribed to the formation of a rigid network with filler/filler interactions. In addition, interactions between the filler and the matrix as well as the dispersion quality were found to play a major role on the mechanical properties of the composites when investigation of the films was performed in the nonlinear region.

Biocompatible Materials↗
PubMed2003

A new, simple, safe, effective and cost-effective procedure for genuine stress incontinence: midurethral polypropylene sling.

We developed a cost-effective procedure for genuine stress incontinence (GSI) that has the advantages of the tension-free vaginal tape (TVT). The midurethral polypropylene sling procedure (MPS) is carried out under local anaesthesia. A self-fashioned sling (7.5 x 1 cm) was created from a polypropylene mesh with two lengthening polypropylene sutures at the ends. The sutures are carried through the rectus fascia using a needle and the sling is placed around the urethra. Ten patients underwent the MPS and were followed up for a mean of 6.2 months. All patients were cured. The short-term results of the MPS were comparable to those of the TVT. The procedure costs approximately US dollar 9. We conclude that the MPS can be considered as an alternative to the TVT procedure.

Female↗
PubMed2002

Randomized clinical trial of suture repair, polypropylene mesh or autodermal hernioplasty for incisional hernia.

BACKGROUND: Since conventional suture repair for incisional hernia is associated with high recurrence rates, alloplastic and autoplastic prosthetic techniques have been suggested. METHODS: In a randomized trial, 160 patients with simple or complex hernias underwent either suture repair, autodermal skin graft or onlay polypropylene mesh repair. Suture repair was not done in complex hernias. This report concerns a planned interim analysis. RESULTS: At mean follow-up of 16 months, there were 17 hernia recurrences that were distributed similarly between the surgical techniques. There were fewer infectious complications after suture repair (three of 33 patients) than after skin graft or mesh repair (seven of 39 and five of 28 for simple hernias; seven of 31 and ten of 29 respectively for complex hernias) (P not significant). The severity of infections after polypropylene mesh implantation prompted the trial committee to discontinue the study. No differences were noted in duration of stay in hospital and quality of life. However, pain was significantly more frequent after polypropylene mesh repair (pooled risk ratio 2.9 and 1.8 at 6 weeks and 1 year respectively). CONCLUSION: Suture repair was safe for small incisional hernias. Both autoplastic and alloplastic hernia repair yielded comparably low recurrence rates, but led to a high rate of wound infection.

Female↗
PubMed2001

Comparison of mechanical properties of polyvinylidene fluoride and polypropylene monofilament sutures used for flexor tendon repair.

We performed an experimental study to evaluate the mechanical properties of polyvinylidene fluoride sutures and to compare their use with that of standard polypropylene sutures for the circumferential, epitendinous suture of a flexor tendon repair. Polyvinylidene fluoride sutures had a smaller suture diameter, a greater knot pull strength and less delayed extension when under creep testing, than polypropylene sutures. Tendons repaired using polyvinylidene fluoride sutures had significantly greater gap and breaking strengths than those repaired using polypropylene sutures.

Animals↗
PubMedDate not supplied

Effects of electron beam irradiation on the migration of antioxidants and their degradation products from commercial polypropylene into food simulating liquids.

The influence of electron beam irradiation on migrational behaviour of additives present in food packaging material was studied. The migration experiments were carried out on irradiated and non-irradiated polypropylene pouches containing aqueous food simulating liquids (FSL) for 10 days at 40 degrees C. The controls were irradiated and non-irradiated pouches without FSL contact. After the contact period, the polypropylene and the FSL were analysed. A comparison between the results obtained by the two analyses showed the migration of three products of antioxidant degradation from the polypropylene into the FSL, and a partial decomposition of these migrants in the FSL.

Absorption↗
PubMedDate not supplied

Food and packaging interactions: determination of the kinetic parameters of olive oil diffusion in polypropylene using concentration profiles.

The penetration of olive oil into polypropylene was studied in order to allow a complete modellization of food and packaging interactions. Oil concentration profiles through polypropylene food trays were determined by FTIR-microscopy measurements along the thickness at various times. Calculations of the relevant parameters characterizing Fickian diffusion, namely constant diffusivity, coefficient of convective mass transport on the surface and concentration at equilibrium were carried out. This way of working has proven to be considerably shorter and more accurate than the method consisting of recording the global absorbance of the substance absorbed, especially when the amount of diffusing fat is low. Major conclusions are: that absorption of olive oil is strongly influenced by convection; the diffusion coefficient of olive oil in polypropylene is constant. Possible consequences to simplify global migration testing are discussed.

Diffusion↗
PubMed1996

Stability of thiopental sodium and propofol in polypropylene syringes at 23 and 4 degrees C.

The stability of thiopental sodium and propofol in an admixture stored in polypropylene syringes at room temperature and under refrigeration was studied. Propofol injection 10 mg/ mL and thiopental sodium 25 mg/mL were mixed to final concentrations of 5 and 12.5 mg/mL, respectively. The admixture was put into 60-mL polypropylene syringes, and two syringes were stored at 23 degrees C and two at 4 degrees C. For solutions stored at 23 degrees C, samples were taken at 0, 4, 8, 24, 48, 72, 120, 168, 216, 240, and 264 hours, and for samples stored at 4 degrees C, samples were taken at 0, 4, 8, 24, 48, 72, 120, 168, 216, and 312 hours. Drug concentrations were determined by high-performance liquid chromatography. Thiopental sodium and propofol retained > 90% of their initial concentrations for up to 312 hours at 4 degrees C. At 23 degrees C, > 90% of the initial concentration was retained by propofol for up to 120 hours and by thiopental sodium for up to 240 hours. No visual changes or significant change in pH occurred in any sample. When mixed and stored in polypropylene syringes, propofol 5 mg/mL and thiopental sodium 12.5 mg/mL were stable for up to 312 hours at 4 degrees C and for up to 120 hours at 23 degrees C.

Anesthetics, Intravenous↗
PubMed1998

Stability of reconstituted indomethacin sodium trihydrate in original vials and polypropylene syringes.

The stability of reconstituted indomethacin sodium trihydrate 0.5 mg/mL in sterile water for injection for 14 days at either 2-6 degrees C or room temperature (21-25 degrees C) in the drug's original vial and in polypropylene syringes was studied. Twenty 1-mg vials of indomethacin sodium trihydrate were reconstituted with 2 mL of Sterile Water for Injection, USP. Solution from 10 vials was drawn into 20 1-mL disposable polypropylene syringes. Five vials and 10 syringes were stored at 21-25 degrees C, and the other 5 vials and 10 syringes were stored at 2-6 degrees C. Samples were taken on days 0, 1, 2, 4, 5, 7, 9, 12, and 14 and analyzed by liquid chromatography. Physical inspections and pH determinations were made as well. Throughout the study period, all solutions stored at 2-6 degrees C retained more than 95% of the initial indomethacin concentration. At room temperature, solutions stored in syringes retained more than 95% of the initial indomethacin concentration. Solutions stored in glass vials contained only 89.7% of the initial concentration on day 14. Solutions stored at room temperature in either syringes or vials had greater amounts of degradation products than solutions stored at 2-6 degrees C. Reconstituted indomethacin sodium trihydrate 0.5 mg/mL was stable for 14 days when stored in polypropylene syringes at 2-6 or 21-25 degrees C and in its original glass vials at 2-6 degrees C. When stored in the glass vials at 21-25 degrees C, the reconstituted drug was stable for 12 days.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1981

Emergency abdominal wall reconstruction with polypropylene mesh: short-term benefits versus long-term complications.

The acute replacement of full-thickness abdominal wall has been facilitated by polypropylene mesh (Marlex) (PPM), allowing debridement of nonviable tissue and restoration of abdominal wall integrity without tension. However, no substantial long-term follow-up has been reported on the definitive wound coverage after the use of PPM in open wounds. Since 1976, we have placed PPM in 31 patients; 25 for infectious complication, three for massive bowel distension preventing abdominal closure, and three for shotgun wounds with extensive tissue loss. In 29 of 31 patients, the mesh was placed in heavily contaminated wounds; extensive fasciitis was present in 23 patients and 21 had intra-abdominal abscesses. Following mesh placement, 23 reoperations were required for continuing complications. No patients eviscerated, despite these multiple procedures. Polypropylene mesh was highly effective in restoring abdominal wall continuity. Despite advantages when PPM was used, significant long-term problems developed. Seven patients died from their primary illness in the postoperative period. Nine wounds were closed by granulation and subsequent split-thickness skin grafts. All nine developed mesh extrusion and/or enteric fistulae. Nine wounds healed by secondary intention, six developed enteric fistulae or continuing mesh extrusion. Full-thickness flap coverage after granulation provided the best means of wound closure. Polypropylene mesh had significant early advantages for providing abdominal wall integrity even in the presence of severe infection. However, long-term problems were common when wounds were closed to skin grafts or secondary intention. If the mesh cannot be completely removed, strong consideration should be given to myocutaneous flaps for coverage after the primary illness has resolved.

Abdominal Injuries↗
PubMed2003

Prospective analysis of patients treated with a distal urethral polypropylene sling for symptoms of stress urinary incontinence: surgical outcome and satisfaction determined by patient driven questionnaires.

PURPOSE: We evaluated the safety and efficacy of the distal urethral polypropylene sling for stress urinary incontinence using patient self-assessment by questionnaires. MATERIALS AND METHODS: We performed a prospective study of all consecutive patients who underwent a mid distal urethral sling procedure between November 1999 and February 2002. Surgical outcome was determined by symptom, bother and quality of life questionnaires completed by the patients. The physicians were blinded to patient responses. These outcomes were compared to the SEAPI determined by the physician and to physical examination findings. RESULTS: There were 301 patients, of whom 2.3% required treatment for persistent stress urinary incontinence (SUI) after the polypropylene sling procedure. In the 92 patients with a minimum followup of 12 months the objective cure rate was 92%. The patient determined subjective success rate (cure and improved greater than 50%) was 89%. On questionnaires only 69% of the patients reported no symptoms of SUI under any circumstance and the same number reported never being bothered by SUI. The physician determined SEAPI overestimated patient self-reported symptoms by 10% to 50% depending on the symptom. CONCLUSIONS: The polypropylene sling represents an inexpensive, safe and simple alternative treatment for patients with stress urinary incontinence. The procedure provides high objective and physician determined cure rates but a lower patient self-reported subjective cure rate. Patient self-assessment of symptoms, bother and quality of life should be an integral part of the outcome of stress urinary incontinence surgery.

Adult↗
PubMed2004

Time dependent variations in biomechanical properties of cadaveric fascia, porcine dermis, porcine small intestine submucosa, polypropylene mesh and autologous fascia in the rabbit model: implications for sling surgery.

PURPOSE: We investigated time dependent variations in tensile strength, stiffness, shrinkage and distortion in 6 materials commonly used for transvaginal anti-incontinence surgery. MATERIALS AND METHODS: A total of 15 rabbits were randomized into 3 survival groups (2, 6 and 12 weeks, respectively). Each rabbit had human cadaveric fascia, porcine dermis, porcine small intestine submucosa, polypropylene mesh and autologous fascia implanted on the anterior rectus fascia. At harvest tensiometry and image analysis were performed on each sling. Results were compared to baseline for each sling type and the percent decrease from baseline was compared among sling types. RESULTS: Each type of human cadaveric fascia and porcine allografts showed a marked decrease (60% to 89%) in tensile strength and stiffness from baseline. Polypropylene mesh and autologous fascia did not differ in tensile strength from baseline. Polypropylene mesh increased in stiffness from baseline. Autologous fascia and small intestinal submucosa demonstrated a 41% and 50% decrease in surface area, respectively, at 12 weeks. CONCLUSIONS: To our knowledge the relative contribution of biomechanical properties of sling material to the success of anti-incontinence surgery is unknown. However, rapid loss of tensile strength and stiffness in porcine and cadaveric materials may contribute to the early re-emergence of symptoms following successful sling surgery. The results of this study add scientific validity to the increasing use of synthetics in anti-incontinence surgery. Urologists selecting a sling material should be aware of its time dependent biomechanical fate relative to other sling materials.

Animals↗
PubMed2004

Does Valsalva leak point pressure predict outcome after the distal urethral polypropylene sling? Role of urodynamics in the sling era.

PURPOSE: Recently sling procedures have been shown to be effective in the treatment of all types of incontinence. In this study we evaluated the role of preoperative Valsalva leak point pressure (VLPP) in predicting the outcome of sling surgery. MATERIALS AND METHODS: We prospectively evaluated 174 consecutive patients who underwent a distal polypropylene sling procedure for the treatment of stress urinary incontinence (SUI). Using SEAPI scores patients were divided by VLPP into group 1-60 patients who did not leak on urodynamics, group 2-27 patients with VLPP greater than 80 cm H2O, group 3-71 patients with VLPP 30 to 80 cm H2O and group 4-16 patients with VLPP less than 30 cm H2O. Surgical outcomes were determined by symptom, bother and quality of life questionnaires filled out by patients. The physicians were blinded to patient response. RESULTS: Mean followup was 14.7 months (range 12 to 30) and mean patient age was 62 years (range 32 to 88). The groups were well matched before surgery with respect to age, number of previous surgeries, and severity of SUI symptoms and urge incontinence. The percentage of patients who were cured or improved was similar among groups. After surgery there was no statistical difference among patient mean self-reported symptoms of or bother from SUI or urge incontinence. CONCLUSIONS: The distal urethral polypropylene sling provides similar symptom improvement in all patients regardless of preoperative VLPP. VLPP is helpful in the diagnosis of SUI but appears to be of minimal benefit in predicting the outcome of the distal urethral polypropylene sling procedure.

Adult↗
PubMed2005

Diagnosis, management and prognosis of vaginal erosion after transobturator suburethral tape procedure using a nonwoven thermally bonded polypropylene mesh.

PURPOSE: We studied the diagnosis, management and prognosis of vaginal mesh erosion using a thermally bonded nonwoven polypropylene mesh in a transobturator suburethral tape procedure for the surgical treatment of stress urinary incontinence in women. MATERIALS AND METHODS: A total of 65 patients diagnosed with stress urinary incontinence underwent a transobturator suburethral tape procedure with a fusion welded, nonwoven, nonknitted polypropylene mesh, with or without a central silicone coated section, at our institution. All women were followed and if vaginal erosion was diagnosed, cystoscopy and vaginoscopy were performed, the mesh was partially or completely removed and, if necessary, posterior cough test and urodynamic study were performed. RESULTS: Of the 65 patients 9 (13.8%) were diagnosed with vaginal erosion at the vaginal incision during a relatively long postoperative period (mean 290 days). All presented with vaginal discharge and 1 had a severe complication (obturator abscess). Complete mesh removal was necessary in 8 patients and only 2 (22%) had recurrent stress urinary incontinence. CONCLUSIONS: A 13.8% rate of vaginal mesh erosion using a nonwoven thermally bonded polypropylene mesh was reported. This complication was probably due to the characteristics of the mesh and not to the transobturator approach. Complete removal of the tape is recommended and the continence status prognosis is good (78%).

Adult↗
PubMed2005

Endoscopic holmium laser excision of intravesical tension-free vaginal tape and polypropylene suture after anti-incontinence procedures.

PURPOSE: We report on our technique of endoscopic excision of intravesical tension-free vaginal tape procedure and polypropylene sutures using the holmium laser following various anti-incontinence procedures. MATERIALS AND METHODS: Three patients who previously underwent the tension-free vaginal tape, Burch colposuspension and Stamey vesicopexy, respectively, presented with a range of symptoms including hematuria, recurrent urinary tract infection, frequency, urgency and urinary incontinence. Patients were evaluated with history and examination, and all 3 were found to have nonabsorbable intravesical material. RESULTS: There was obvious encrustation over the eroded polypropylene material within the bladder. A 365 microm tip firing holmium laser fiber was inserted through the working channel of the flexible cystoscope. The tape and sutures were successfully excised using a holmium laser output of 1.0 J per pulse at a rate of 10 Hz. Mean operative time was 15 minutes. CONCLUSIONS: Holmium laser excision of intravesical polypropylene tape or suture is a minimally invasive solution to the problem of intravesical perforation or erosion following anti-incontinence procedures.

Endoscopy↗
PubMedDate not supplied

On the use of unsealed polypropylene mesh as tracheal replacement.

The necessity of a cervical tracheal replacement arises with thyroid carcinoma, which occasionally infiltrates the trachea extensively, the rare primary tracheal tumors and, sporadically, benign stenoses. In the present study, we used an uncoated porous polypropylene prosthesis as cervical tracheal replacement in sheep. Specifically, we implanted a tracheal prosthesis of polypropylene mesh as a cervical tracheal replacement in five sheep, protecting the airways with self-expanding stents. Healing-in of the prostheses was checked bronchoscopically. The animals were killed after increasing survival times (7, 28, 64, 68, and >90 days), and incorporation of the prosthesis was examined macroscopically, microangiographically and histologically. Although medium-term survival was possible with a sufficiently wide airway, all animals were ultimately euthanized because of complications (airway stenosis, prolapse of prosthesis). Nevertheless, the results show that replacement of the cervical trachea with a polypropylene mesh can be successful under different experimental conditions.

Animals↗