Tensile properties of five commonly used mid-urethral slings relative to the TVT™

We characterized the tensile properties of five mid-urethral slings relative to the Gynecare TVT™. Slings were divided and loaded to failure. The heat-sealed Boston Scientific mid-section and the American Medical Systems (AMS) tensioning suture were examined separately. Analysis of the resulting nonlinear load elongation curves included calculation of low and high stiffness, the transition point between them (inflection point), load at failure, and relative elongation. Permanent elongation was measured after repetitive loads. Mean values were compared using a one-way analysis of variance. The curves of the Gynecare, Boston Scientific (no midsection) and AMS (no suture) were nonlinear with similar low stiffness and inflection points. The Bard, Caldera, and Mentor slings were stiffer. Heat sealing the Boston Scientific mid-section increased stiffness, while the AMS suture had negligible effect. Cyclical loading induced permanent elongation that was similar for Gynecare, AMS, and Boston Scientific (without mid-section) and lower for Bard, Caldera, and Mentor. With the exception of AMS, the overall effect of newer sling modifications was an increase in tensile stiffness.     

Effects of resterilization on mechanical properties of polypropylene meshes

BACKGROUND: The re-use of sterile packaged polypropylene meshes in hernia surgery is not recommended by the manufacturers. However, especially in developing and underdeveloped countries, many surgeons are obliged to re-use the mesh pieces after resterilization because of economic problems. The purpose of this study was to determine the effects of ethylene oxide and autoclave resterilization on the mechanical properties of polypropylene meshes. METHODS: Repetitive ethylene oxide gas and autoclave sterilizations were applied to polypropylene meshes (Herniamesh S.r.l., San Mauro, Italy) up to 3 times and the effects on the mechanical properties were examined. Gas resterilizations were applied for 4.5 hours at 55 degrees C, whereas for autoclave resterilizations the specimens were kept at 134 degrees C and 3 atm pressure for 64 minutes. Ethylene oxide gas-sterilized samples were labeled as G(n) and autoclave-sterilized samples were labeled as A(n). Effects of the resterilizations on maximum load (Fmax), elongation at maximum load (deltaL), and energy required for complete failure of the specimen (E) were measured. RESULTS: Fmax in the groups showed no significant differences. DeltaL values of groups A2, A3, and G3 were found to be significantly lower in comparison with the control group, whereas differences between the control group and other groups were not statistically significant. E values of A2 and A3 groups were significantly lower than that in the control group (P < .05), whereas the differences between the control group and other groups were not found to be statistically significant. No significant variations were determined between samples sterilized 1, 2, or 3 times in scanning electron microscopy micrographs, however, small irregularities were observed on autoclaved samples. CONCLUSIONS: Single use of polypropylene meshes is always recommended because of biocompatibility and infection risks. However, if re-use of the open packages is needed, ethylene oxide sterilization is preferred over autoclave sterilization. If ethylene oxide sterilization is not available then 1 cycle of resterilization with an autoclave can be used.     

Experimental biomechanical evaluation of polypropylene prostheses used in pelvic organ prolapse surgery

Introduction and hypothesis  Although polypropylene (PP) is the most common biomaterial used to repair genital prolapse via vaginal route, its mechanical properties however remain obscure. Methods  An abdominal hernia rabbit model was used to evaluate retraction, solidity, and elasticity of the principal types of PP prostheses currently available, i.e., three large pore size monofilament prostheses, one heavy weight (HWPP), a second low weight (LWPP), and a third coated with atelocollagen (CPP). A small pore size multifilament PP (MPP) implant was also tested. Results  In comparison with HWPP (12%), LWPP (15%), and MPP (30%), CPP had less retraction (8% of the original size). Unlike pore size, weight prosthesis is not an influencing factor for retraction. Atelocollagen coating reduced retraction. HWPP and MPP were the most solid prostheses. MPP supported the greatest elastic force. Conclusions  When the biomechanical parameters were comparatively assessed, HWPP was considered to have the most advantageous properties for prolapse surgery.     

Biomechanical properties of raw meshes used in pelvic floor reconstruction

Female urinary incontinence and pelvic organ prolapse are common conditions. The aim of this study was to assess the biomechanical properties of raw meshes commonly used in pelvic floor surgery, particularly the effects of cyclical loading on these meshes. The material properties of nine different types of surgical meshes were examined using uniaxial tensile tests. The strength and extensibility of the mesh designs differed considerably. Most mesh types exhibited curvilinear loading curves. Cyclical loading of mesh samples produced significant permanent deformation in all mesh designs. This non-recoverable extension ranged from about 8.5% to 19% strain. Hysteresis also varied considerably between materials from 30% to 85%. All mesh groups tested for their biomechanical properties displayed differences in results for failure load, stiffness, non-recoverable extension and hysteresis.     

Short-term outcome after transvaginal mesh repair of pelvic organ prolapse

The objective of this study is to report on short-term outcomes after pelvic organ prolapse repair using Prolift® transvaginal mesh. A 3-year multicenter prospective cohort study was performed in 28 centers. Assessment preoperatively and at 2 months postoperatively included the condition-specific pelvic organ prolapse quantification system (POP-Q) and a macroscopic inflammatory scale. Subjective outcome was measured using the urogenital distress inventory (UDI) and the incontinence impact questionnaire (IIQ-7). Surgical characteristics and adverse events during follow-up were registered in a separate protocol. The evaluation is based on the interim safety analysis and includes 2-month evaluations of 123 cases. Pelvic organ perforation occurred in four cases (3.2%), three bladder injuries and one case of rectal perforation. At the 2-month follow-up, there were two cases of mesh exposure, an increase of mild–moderate granuloma formation in the operated areas (P?P?相似文献   

Laparoscopic rectopexy for external prolapse in children

Purpose

This study reports the results of laparoscopic rectopexy in children.

Methods

Results were obtained from a prospective database for all laparoscopic rectopexy procedures performed for external prolapse in a tertiary referral centre from 2006 to 2013. Outcomes included recurrence of symptoms and/or visible prolapse as well as the need for further surgery

Results

Eighteen procedures including both suture and mesh rectopexy were performed in 11 patients. Six had solitary rectal ulcers. All patients had failed conservative management, including laxative therapy, and one patient had previously had a trial of injection of hypertonic saline. At a median follow up of 33 months (6–75) complete resolution was seen in 7 cases and partial resolution, with some continuing symptoms, was seen in 1 patient. All suture rectopexy cases ultimately failed and required a redo rectopexy procedure. Three patients had persistent failure with recurrence of prolapse during the study period despite repeated procedures. There were no serious complications.

Conclusions

Laparoscopic mesh rectopexy can be safely performed in children and can lead to complete resolution of external prolapse. There is a cohort for whom it fails to relieve the problem. In this series there was a trend towards less recurrence with mesh rectopexy.     

Biocompatibility of bacterial contaminated prosthetic meshes and porcine dermal collagen used to repair abdominal wall defects

Background and aims A contaminated or infected surgical site is considered a contraindication for the use of the nonabsorbable alloplastic materials employed to repair abdominal wall defects. Therefore, the biocompatibility of new prosthetic materials was investigated. Materials and methods Meshes measuring 1.5×1.5 cm made of conventional and titanium-coated polypropylene, polyglycol, or porcine dermal collagen were implanted under the abdominal wall of 96 rats (eight groups of 12 animals each) employing the inlay technique. Implantation of all four materials was performed both under semisterile conditions and bacterial contamination of the mesh. The meshes were explanted after 28 days. Results All the materials implanted under semisterile conditions were incorporated into the abdominal wall with only few intraabdominal adhesions (mean adhesion scores: 1.0, 1.2, 1.0, 0.8 points, respectively, not significant). With the porcine dermal collagen, proliferation rate and the proportion of inflammatory cells were statistically lower (p<0.01). In the bacterial contamination group, all meshes were associated with a suppurating infection and strong adhesions between the bowel and mesh, which were most prominent in the case of dermal collagen (mean adhesion scores: 1.6, 1.7, 1.7, and 1.9 points, respectively, not significant). In this group, two animals died of peritonitis. In comparison with the other materials, the proliferation rate was significantly elevated (p=0.03). No significant differences were seen between the other materials employed. Conclusion Irrespective of the material employed, implantation of alloplastic meshes in an abdominal wall contaminated with bacteria, is associated with suppurating infections, in particular in the case of the membrane-like porcine dermal collagen. Nonabsorbable alloplastic meshes and dermal skin grafts should therefore not be used to repair infected abdominal wall defects.     

Abdominal hysterectomy and Burch colposuspension for uterovaginal prolapse

The recurrence rate for prolapse in patients who underwent abdominal hysterectomy and sacrocolposuspension for genital prolapse were determined. Patient records were reviewed and 58 patients who had undergone abdominal hysterectomy for genital prolapse and sacrocolposuspension with mesh were included. The patients median age was 47.0 years and parity 3. Preoperatively, 25 patients (43%) presented with bladder symptoms, 17 (29%) with bowel symptoms and 45 (78%) with something protruding through the vagina. All patients underwent hysterectomy, of which 51 (88%) were subtotal. Colposuspension was performed by inserting a mesh from the mid-vagina to the sacrum (S1). A Burch colposuspension was performed in 50 patients (87%). The median follow-up was 20 months. Six patients (10%) developed recurrent prolapse, of which five (9%) underwent repeat surgery. There were no mesh erosions. The recurrence rate for prolapse was low, indicating that abdominal hysterectomy with sacrocolposuspension is an excellent option for uterovaginal prolapse.Editorial Comment: It has long been felt that the optimal route for hysterectomy in patients with uterovaginal prolapse was via the vaginal approach. While this may be the most facile way to accomplish the hysterectomy, it may not be the best way to re-support pelvic defects and prevent recurrent prolapse. The aim of this paper is to determine if an abdominal approach to hysterectomy and correction of pelvic defects successfully corrects the defects and prevents recurrence of pelvic prolapse. This is a question worthy of study. Unfortunately, the study population and the procedures performed were too diverse to answer this question.     

Functional impairment and complaints following incisional hernia repair with different polypropylene meshes

The influence of mesh material on the clinical outcome of hernia repair has often been neglected, although recent studies have clearly demonstrated the importance of mesh properties for integration in the abdominal wall. Of particular significance are the amount of mesh material and the pore size. In the following study, patients received different mesh types with distinct amounts of polypropylene and of various pore sizes for incisional hernia repair. We investigated whether the type of material influenced the clinical and functional outcomes. Between 1991 and 1999, 235 patients received polypropylene meshes in a sublay position for incisional hernia repair: 115 patients were implanted with a Marlex heavy-weight mesh (Mhw mesh), 37 patients with an Atrium heavy-weight mesh (Ahw mesh) and 83 with a Vypro low-weight mesh (Vlw mesh). The study protocol included ultrasound examination and 3D-stereography in all patients, with a total follow-up of 24±13 months (Mhw-mesh), 11±8 months (Ahw-mesh) and 8±7 months (Vlw-mesh). Our findings demonstrate that the side effects of mesh implantation, comprising paraesthesia and restriction of abdominal wall mobility, were significantly affected by the type of material implanted. Three-dimensional stereographic examinations were well in accordance with our clinical findings. Our data support the hypothesis that the use of low-weight large-pore meshes is advantageous for abdominal wall function. Electronic Publication     

Transvaginal mesh technique for pelvic organ prolapse repair: mesh exposure management and risk factors

Prosthetic reinforcement in the surgical repair of pelvic prolapse by the vaginal approach is not devoid of tolerability-related problems such as vaginal erosion. The purposes of our study are to define the risk factors for exposure of the mesh material, to describe advances and to recommend a therapeutic strategy. Two hundred and seventy-seven patients undergoing surgery due to pelvic prolapse with transvaginal mesh technique were included in a continuous, retrospective study between January 2002 and December 2003. Thirty-four cases of mesh exposure were observed within the 2 months following surgery, which represents an incidence of 12.27%. All the patients were medically treated, nine of whom were found to have completely healed during the check-up performed at 2 months. In contrast, 25 patients required partial mesh exeresis. Risk factors of erosion were concomitant hysterectomy [OR=5.17 (p=10⁻³)] and inverted T colpotomy [OR=6.06 (p=10⁻²)]. Two technical guidelines can be defined from this study as regards the surgical procedure required in order to limit mesh exposure via the vaginal route. The uterus must be preserved, and the number and extent of colpotomies needed to insert the mesh must be limited.     

Structural alterations of prosthetic meshes in humans

The use of prosthetic mesh in abdominal wall hernia surgery is a well-accepted practice. What is not settled, however, is the type of prosthesis that best suits the purpose. The narrow choice today means a prosthesis of polyester or polypropylene. These are available in many designs, configuration of weave, thickness of weave and strand, and size of pore. There has been a pervasive feeling that these materials "shrink". To what extent they do has not been accurately defined. This study was designed to measure such "shrinkage". Interestingly, our measurements revealed that prosthetic meshes could "expand" as well as "shrink". The extent to which they do varies between –40% and 58.5%. Whereas it was felt that fibrocyte activity and its eventual scar formation accounted for the "shrinkage" of the mesh, we have discovered that structural alterations in the size of the mesh pores can be affected by distilled water, saline, blood, formalin, bleach, as well as in vivo implantation. Prosthetic meshes are, therefore, not the inert materials they are claimed to be and can expand as well as shrink. We have, unfortunately, not been able to correlate the degree or direction of change to any known parameter. Electronic Publication     

Anatomical outcome and quality of life following posterior vaginal wall prolapse repair using collagen xenograft

The aim of this study was to evaluate quality of life, sexual function, and anatomical outcome after posterior vaginal wall prolapse repair using a collagen xenograft. Thirty-three patients were evaluated preoperatively and at 6 and 12 months follow-up (FU). Quality of life and sexual function were assessed using a self-reported questionnaire. Prolapse staging was performed using the pelvic organ prolapse quantification system (POPQ). Preoperatively 3 patients had stage I, 26 patients stage II, and 4 patients stage III prolapse of the posterior vaginal wall. Prolapse of the posterior vaginal wall stage II was observed in 7 patients (21%) at the 6-month FU and in 13 patients (39%) at the 12-month FU. Mean point Bp was reduced from –1.1 preoperatively to –2.5 at 6 months FU (p<0.01) and –1.8 at 12 months FU (p<0.01). Previous abdominal surgery was associated with a less favorable anatomical outcome (odds ratio: 2.0, 95% confidence interval: 1.5–3.8). There were no significant changes in sexual function or dyspareunia during the 1-year FU. Preoperatively 76% of the patients reported a negative impact on quality of life as a result of genital prolapse. There was a significant improvement in several variables associated with quality of life at 6 and 12 months FU. Posterior vaginal wall prolapse repair using a collagen xenograft was associated with an unsatisfying anatomical outcome at 1-year FU although several quality of life-associated variables affecting psychosocial function were improved. Improvement was not restricted to postoperative restoration of vaginal topography, and previous surgery had a negative effect on anatomical outcome.     

Characterization of the structure and properties of authentic and counterfeit polypropylene surgical meshes

A counterfeit version of the Ethicon Prolene polypropylene mesh was distributed to hospitals and clinics and unintentionally implanted into patients undergoing tension-free hernia repair. On December 19, 2003, the Food and Drug Administration (FDA) issued a public health web notification indicating that the counterfeit mesh was not sterile or safe to use. To develop safety recommendations for patients with the counterfeit mesh implant, we compared the counterfeit’s structural, physical, chemical and mechanical properties with polypropylene meshes previously cleared by FDA. The mesh fibers for all the products tested were found to have similar chemical and physical properties. The mechanical properties were directly related to the knitted structure (loop size, repeat distance, fabric tightness) and the porosity. Extracts from the counterfeit mesh passed cytotoxicity screening tests. The FDA further recommended that if the mesh had been inadvertently implanted, then those patients should be monitored as would be the practice for any patient with an implanted surgical mesh.     

Bacteriological analysis of meshes removed for complications after surgical management of urinary incontinence or pelvic organ prolapse

The aim of this study is to examine the role of bacterial infection in complications following surgical management of urinary incontinence and genital prolapse using meshes. There were sixteen prostheses removed. Eight were monofilament polypropylene-knitted meshes, one was a silicone-coated polypropylene mesh, another was a collagen-coated polypropylene mesh, four were silicone-coated polyester meshes and two were polyester meshes. The most frequent cause for removal was symptomatic vaginal erosion (62%). Cultures were performed under aerobic, anaerobic and enrichment conditions. Infection was multimicrobial for 31% of meshes. When only one bacteria was found, it was Proteus mirabilis in 25% of cases. Forty-three per cent of bacterial quantifications were under 10³ colony-forming units per millilitre. Bacterial contamination was found in all meshes, quantification was often low, and therefore, its exact role is not yet clear.     

Transvaginal repair of genital prolapse: preliminary results of a new tension-free vaginal mesh (Prolift™ technique)—a case series multicentric study

Our goal was to report the preliminary results of a transvaginal mesh repair of genital prolapse using the Prolift™ system. This retrospective multicentric study includes 110 patients. All patients had a stage 3 (at the hymen) or stage 4 (beyond the hymen) prolapse. Total mesh was used in 59 patients (53.6%), an isolated anterior mesh in 22 patients (20%) and an isolated posterior mesh in 29 patients (26.4%). We report one bladder injury sutured at surgery and two haematomas requiring secondary surgical management. At 3 months, 106 patients were available for follow-up. Mesh exposure occurred in five patients (4.7%), two of them requiring a surgical management. Granuloma without exposure occurred in three patients (2.8%). Failure rate (recurrent prolapse even asymptomatic or low grade symptomatic prolapse) was 4.7%. According to the perioperative and immediate post-operative results, Prolift™ repair seems to be a safe technique to correct pelvic organ prolapse. Anatomical and functional results must be assessed with a long-term follow-up to confirm the effectiveness and safety of the procedure.     

In vivo studies comparing the biocompatibility of various polypropylene meshes and their handling properties during endoscopic total extraperitoneal (TEP) patchplasty: an experimental study in pigs

Background: Polypropylene (PP) meshes are currently being used in millions of operations for hernial repair. We tested several recently modified PP meshes to evaluate them in terms of their biocompatibility and handling characteristics during minimally invasive procedures. Methods: Four different PP meshes (a heavyweight PP, Atrium; a lightweight PP incorporating absorbable polyglactic acid, Vypro II; a lightweight PP, Parietene; and a titanium-coated lightweight PP, Ti-Mesh Extralight), all implanted using the endoscopic total extrapreperitoneal (TEP) technique, were investigated in groups comprising 11 pigs each. After 94 ± 5 days, the animals were autopsied and tissue samples were studied histologically, immunohistochemically, and electron-microscopically. Results: Whereas endoscopic handling of the Vypro II mesh proved difficult, the already good properties of the Atrium mesh were significantly improved on by Parietene and the Ti-Mesh. Clear differences were also found in the shrinkage characteristics of the implant materials. In comparison with Atrium (12%), Vypro II mesh shrinkage was significantly greater (28%), whereas Parietene (7%) and Ti-Mesh (5%) incurred less shrinkage. With regard to the chronic inflammatory reaction, the titanium-coated mesh showed a significantly lower inflammatory activity (13.1% partial volume [%PV] vs 34.1%PV and 29.0%PV) than the lightweight meshes Vypro II and Parietene, but—with the exception of the monocytic (0.2 vs 9.1, 5.1, and 7.9) and B-lymphocytic reaction (1.1 vs 18.0, 11.7, and 12.2)—no significant difference was seen in comparison with Atrium. The various mediators in the extracellular matrix (matrix metalloproteinases 1 [MMP-1 transforming growth factor beta [TGF-], urokinase plasminogen activator [uPA], and type I collagen) tended to show the highest expression with Vypro II (13.6, 113.2, 132.7, and 139.5, respectively) and the lowest expression with Ti-Mesh (11.9, 68.5, 92.8, and 75.0, respectively). With regard to cell proliferation, Parietene and Ti-Mesh appeared to have slight advantages, but no differences were observed in the apoptotic rate. Conclusion: In our opinion, despite a reduction in material, Vipro II, on account of the inflammatory reaction, does not represent a true improvement over the meshes currently used for hernia repair. In comparison, the two lightweight PP patches are characterized by a more favorable foreign body reaction, with the titanium coating of the Ti-Mesh providing an additional advantage in terms of its biocompatibility.     

Urethral prolapse after durasphere injection

Urethral prolapse is an uncommon condition among adult patients. We report a case of adult female patient with urethral prolapse after Durasphere injection. The patient was successfully treated with excision of the prolapsed urethra and Durasphere mass, and fibrin glue injection to support the remaining part of urethra.     

The history and evolution of pessaries for pelvic organ prolapse

The use of pessaries for the treatment of genital prolapse dates back prior to the days of Hippocrates and their use has been documented in early Egyptian papyruses. Throughout the centuries remedies such as honey, hot oil, wine and fumes have been used as treatment. Mechanical methods included succussion and leg binding. Pomegranates were also common remedies. In the middle ages, linen and cotton wool soaked in many different potions were used. As new materials were discovered, pessaries evolved and began to resemble those used today. Cork and brass were soon replaced with rubber. Modern day pessaries are made of non-reactive silicone and come in various designs and sizes to suit each individual. Pessaries can be used as an interim measure for women who wish to complete childbearing or women awaiting surgery. It can also be used as a permanent measure for women who are unsuitable for surgery. It remains to be established whether the use of modern pessaries over prolonged periods of time can prevent progression of or even cure, prolapse.     

Vesical prolapse in an apparently "normal" bladder

Bladder prolapse is extremely rare in children. Reports have been limited to pathologic bladder conditions such as the exstrophy-epispadias complex. We report an interesting presentation of bladder prolapse in a child with Williams syndrome with an apparently normal bladder.     

Gastroduodenojejunal prolapse

A patient presented with symptoms of gastric outlet obstruction. On evaluation she was found to have a polypoidal lesion in the proximal jejunum on upper gastrointestinal barium series. Endoscopic evaluation showed the gastric mucosa prolapsing into the duodenum. At laparotomy, the gastric mucosa was found to prolapse into the jejunum via the duodenum. Excision of the prolapsed mucosa resulted in resolution of the patient's symptoms.