The amenorrhea as a protective factor for healing of hysterotomy - a retrospective analysis one year postpartum.

OBJECTIVES: The good healing of the hysterotomy after cesarean section is important for subsequent pregnancies. However, the factors which improve this healing have not been completely described, yet. In this study, we focused on factors which may affect healing of hysterotomy within one year after delivery, such as menstruation, breastfeeding, and the use of the contraception. MATERIAL AND METHODS: Following delivery, total of 540 women were invited for three consecutive visits at six weeks, six months, and 12 months postpartum. The presence of menstruation, frequency of breastfeeding and contraception use were recorded. The scar was evaluated by vaginal ultrasound as already described. The impact of menstruation, breastfeeding, and contraception method on presence of niche was evaluated. RESULTS: The presence of menstruation increased odds to have niche by 45% (CI 1.046-2.018, p = 0.026). Secondarily, our results demonstrated a statistically significant protective effect of breastfeeding on the incidence of niche with OR 0.703 (CI 0.517-0.955, p = 0.024). Breastfeeding decreases odds to have niche by 30%. Also, the use of gestagen contraception lowered the odds by 40% and intrauterine device (IUD) or combine oral contraceptive (COC) by 46.5%. The other possibly intervening factors were statistically controlled. CONCLUSIONS: Amenorrhea, breast-feeding and progesterone-contraceptive decreases the risk of uterine niche within one year follow up.

Laparoscopic single-stapler technique in rectosigmoid resection in women with deep infiltrating endometriosis.

OBJECTIVE: To demonstrate the use of a single-stapler technique during rectosigmoid resection in women with deep infiltrating endometriosis (DIE). DESIGN: A step-by-step video demonstration of rectosigmoid resection and end-to-end anastomosis using two circularly placed sutures and one circular stapler. SETTING: Institute for the Care of Mother and Child, Prague, Czech Republic. PATIENT(S): A 39-year-old woman presented with primary sterility and deep infiltrating endometriosis, and an EZIAN score of A2,B2,C3. A nodule was located 9 cm from the anus and was 38 × 9 mm in size. This included an intramural fibroma of 6 cm and a left-sided ovarian endometriotic cyst of 6 cm. Her pain on the visual analogue scale were dysmenorea 6, dyspareunia 5-6, dyschezie 7, dysuria 0, and acyclic pain 5. INTERVENTIONS: The primary objective was to replace the linear-stapler resection with two simple, strictly circularly placed sutures, to cut the intestinal wall between them, and to form the end-to-end anastomosis with a circular stapler. The one-stapler technique consisted of the following steps: intestinal wall cleansing as in the limited segmental resection; placement of one strictly circular suture just below the DIE nodule, without fixation; placement of the first circular suture just below the DIE nodule, ideally with at least three full-thickness "bites" of the intestinal wall; placement of the second circular stitch approximately 2 cm below the first one in a similar manner (three full-thickness "bites"); interruption of the intestinal wall with a harmonic scalpel; end-to-end intestinal anastomosis with a circular stapler; and airtightness test of the anastomosis. This results in only one incision line and therefore a lower risk of leakage. Intestinal resection time was on average 10 minutes longer compared to that for the linear stapler technique. So far, we have successfully performed the procedure in 25 women. Perioperative leakage was observed in two of these 25 patients in the classical procedure group and in none of the 25 patients in the group with the one-stapler technique. There were no differences in C-reactive protein (CRP) on third and fifth postoperative days or in other complications such as bleeding and pyrexia). The cost of procedure is lowered by the decrease in the number of staplers from 3 to 1. The patients' postoperative follow-up was uneventful, and they were discharged from the hospital at the same time as the women in whom the classical stapler technique was performed. MAIN OUTCOME MEASURES(S): The primary outcome was the development of a new surgical approach to resection rectosigmoid endometriotic nodules that would decrease the number of incision lines on the intestine. The secondary outcome measures were peri- and postoperative complications (i.e., bleeding, intestinal leakage, postoperative infection, CRP), length of the surgery and hospitalization, and cost of the procedure. CONCLUSION: Multiple incision lines following resection of the rectosigmoid colon and end-to-end anastomosis are risk factors for postoperative intestinal leakage. Therefore, a single incision line formed with two circular sutures, and one circular stapler may reduce the risk of postoperative complications and also financial expenses of the procedure. We believe that this method is suitable and easiest for nodules located less than 6 cm from the anal verge because of possible complications with angulation of linear stapler.

Risky sexual behaviour and contraceptive use among young women in the Czech Republic.

OBJECTIVE: This study aimed to obtain sexual and reproductive behaviour data of late adolescent women in the Czech Republic and to analyse the relationships between sexual behaviour and social, demographic, and behavioural factors. METHODS: Data were obtained using the Computer-Assisted Web Interviewing method from 25 April to 2 May 2018 from a representative group of sexually active women aged 18-24 years. Results were statistically evaluated using sign schema on adjusted residuals. RESULTS: A total of 525 women participated (median age of coitarche - 16 years, condom use with/without hormonal contraception - 65%, unprotected sex - 9.3% in the sexual debut). Anamnestic artificial abortion and sexually transmitted disease (STD) rates were 5.3% and 3.8%, respectively. Early coitarche, number of sexual partners, history of abortion, and STDs were positively correlated with current hormonal contraceptive use; the number of sexual partners and use of hormonal contraception were negatively correlated. Hormonal contraceptive users were more likely vaccinated against human papilloma virus (HPV) in comparison with women without any contraception. There was no correlation between risky sexual behaviour, contraceptive use, and socio-demographic factors. CONCLUSION: Women with early coitarche and a high cumulative number of sexual partners have more unwanted pregnancies and STDs; moreover, those with regular coital activity without contraception are less frequently vaccinated against HPV.

Ultrasound cesarean scar assessment one year postpartum in relation to one- or two-layer uterine suture closure.

INTRODUCTION: This study compared healing of the scars after cesarean section during the first postpartum year using a single- or double-layer suturing technique. Scarring was assessed by a transvaginal ultrasound. We explored the appearance and localization of uterine scars with regard to the obstetric history. Our aim was to compare the position of the scar or defect, if present, its dimensions, and any residual myometrium with respect to the suturing technique during the cesarean section. MATERIAL AND METHODS: Women with uncomplicated singleton pregnancies indicated for elective or acute cesarean section were randomly allocated to the uterine closure technique group. During the first postpartum year, their lower uterine segment was examined with a transvaginal ultrasound in three consecutive visits at 6 weeks, 6 months and 12 months. RESULTS: 324 women attended the 12-month visit; of these, 149 underwent single-layer closure of the uterine incision and 175 double-layer technique. A higher proportion of the defects is seen in the single-layer closure technique of suturing. Defects in the single-layer group were wider (0.002) and the residual myometrial thickness in the single-layer group were thinner (0.019). Women who underwent cesarean section at the stage of full cervical dilation had scars that were closer to the external cervical os (0.000). The position of the uterus varies greatly between controls (0.000). The combination of uterine position and scar defect presence changed significantly between controls (0.001), and was significantly dependent on the suturing method (0.003). Defects with or without contact with the uterine cavity changed statistically between controls (0.017). Both types of defects were more common in the single-layer closure technique group. CONCLUSIONS: The findings of this study demonstrate that double-layer technique with the first continuous nonlocking suture followed by a second continuous nonlocking suture is associated with better suture healing and greater residual myometrial thickness. No difference was observed between single- and double-layer closure for the presence of maternal infectious morbidity, wound infection or blood transfusion.

Assessment of Electrospun and Ultra-lightweight Polypropylene Meshes in the Sheep Model for Vaginal Surgery.

BACKGROUND: There is an urgent need to develop better materials to provide anatomical support to the pelvic floor without compromising its function. OBJECTIVE: Our aim was to assess outcomes after simulated vaginal prolapse repair in a sheep model using three different materials: (1) ultra-lightweight polypropylene (PP) non-degradable textile (Restorelle) mesh, (2) electrospun biodegradable ureidopyrimidinone-polycarbonate (UPy-PC), and (3) electrospun non-degradable polyurethane (PU) mesh in comparison with simulated native tissue repair (NTR). These implants may reduce implant-related complications and avoid vaginal function loss. DESIGN, SETTING, AND PARTICIPANTS: A controlled trial was performed involving 48 ewes that underwent NTR or mesh repair with PP, UPy-PC, or PU meshes (n=12/group). Explants were examined 60 and 180 d (six per group) post-implantation. INTERVENTION: Posterior rectovaginal dissection, NTR, or mesh repair. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Implant-related complications, vaginal contractility, compliance, and host response were assessed. Power calculation and analysis of variance testing were used to enable comparison between the four groups. RESULTS: There were no visible implant-related complications. None of the implants compromised vaginal wall contractility, and passive biomechanical properties were similar to those after NTR. Shrinkage over the surgery area was around 35% for NTR and all mesh-augmented repairs. All materials were integrated well with similar connective tissue composition, vascularization, and innervation. The inflammatory response was mild with electrospun implants, inducing both more macrophages yet with relatively more type 2 macrophages present at an early stage than the PP mesh. CONCLUSIONS: Three very different materials were all well tolerated in the sheep vagina. Biomechanical findings were similar for all mesh-augmented repair and NTR. Constructs induced slightly different mid-term inflammatory profiles. PATIENT SUMMARY: Product innovation is needed to reduce implant-related complications. We tested two novel implants, electrospun and an ultra-lightweight polypropylene textile mesh, in a physiologically relevant model for vaginal surgery. All gave encouraging outcomes.

The effect of the first vaginal birth on pelvic floor anatomy and dysfunction.

INTRODUCTION AND HYPOTHESIS: First vaginal delivery severely interferes with pelvic floor anatomy and function. This study determines maternal and pregnancy-related risk factors for pelvic floor dysfunction (PFD), including urinary incontinence (UI), urgency, anal incontinence (AI), pelvic organ prolapse (POP) and levator ani muscle (LAM) avulsion. METHODS: This is a single-centre prospective observational cohort study on healthy women in their first singleton pregnancy. All underwent clinical and 3D transperineal ultrasound examination at 6 weeks and 12 months postpartum. Objective outcomes were POP-Q and presence or absence of LAM trauma. Functional outcomes were measured by the ICIQ-SF and PISQ 12. Multivariate regression was performed to determine birth and maternal habitus-related risk factors for UI, urgency, AI, dyspareunia, LAM avulsion and ballooning. RESULTS: Nine hundred eighty-seven women were included. Risk factors for UI were maternal age per year of age (OR: 1.09; 95% CI: 1.04-1.13; p = 0.0001) and BMI before pregnancy (OR: 1.08; 95% CI: 1.04-1.13; p = 0.001); for POP stage II+ maternal age (OR: 1.08; 95% CI: 1.08-1.14; p = 0.005). Avulsion was more likely after forceps (OR: 3.22; 95% CI:1.54-8.22; p = 0.015) but less likely after epidural analgesia (OR: 0.58; 95% CI: 0.37-0.90; p = 0.015) and grade I perineal rupture (OR: 0.50; 95% CI: 0.29-0.85; p = 0.012). Ballooning was more likely at increased maternal age (OR: 1.08; 95% CI: 1.02-1.13; p = 0.005), epidural (OR: 1.64; 95% CI: 1.06-2.55; p = 0.027) and grade I perineal rupture (OR: 1.79; 95% CI: 1.10-2.90; p = 0.018). CONCLUSION: Though maternal characteristics at birth such as age or BMI increase the risk of PFD, labour and birth factors play a similarly important role. The most critical risk factor for MLA avulsion was forceps delivery, while an epidural had a protective effect.

Interposition of the mesorectal flap as prevention of rectovaginal fistula in patients with endometriosis.

INTRODUCTION AND HYPOTHESIS: Endometriosis is a gynecological condition characterized by endometrial tissue outside of the uterus. It affects up to 15% of women of reproductive age. In the case of bowel infiltration, about 90% of lesions are localized on the sigmoid colon or the rectum and may interfere with bowel function. Three surgical approaches are possible: (1) shaving technique, (2) discoid resection of the nodule, and (3) segmental resection with end-to-end anastomosis. A rectovaginal fistula is feared as a postoperative complication mainly in simultaneous resection of the vaginal and the rectosigmoid nodules. Its prevention is a two-step surgery (the first operation on the vagina and the second on the colon) or a preventive colostomy, both of which are often thought to be too invasive for a benign condition. Herein, we suggest a one-step surgery to prevent its development. METHODS: In three women, a concomitant laparoscopic resection of the vaginal and rectosigmoid endometrial nodule was completed with interposition of a mesorectal flap. RESULTS: All surgeries were uncomplicated with no rectovaginal fistula in the postoperative period. CONCLUSION: In the hands of skilled surgeons, this one-step technique can be used to prevent rectovaginal fistula development.

Morphological and Functional Changes in the Vagina following Critical Lifespan Events in the Ewe.

BACKGROUND/AIMS: The ewe is increasingly being used as an animal model for pelvic floor disorders. The aim was to further characterize changes in the vaginal properties during its entire lifespan. METHODS: Vaginal tissues were collected at different stages of reproductive life (neonatal, prepubescence, nulliparous, primiparous, multiparous, and menopausal; ≥6 ewes/group). Vaginal size, as well as active and passive biomechanics, was measured. Microscopy included thickness of glycogen, epithelium, lamina propria and muscularis thickness, densities of collagen, elastin, smooth muscle, and nerves. RESULTS: Vaginal dimensions increase during adolescence, peak at reproductive levels, and decrease sharply after ovariectomy. One year after first delivery, the distal vagina gets more compliant, yet this is reversed later in life. The thickness of glycogen staining epithelial layers changed with puberty and menopause. The epithelium was markedly thicker after multiple deliveries. The thickness of lamina propria and muscularis increased in puberty and in nulliparous. Semi-quantitative collagen assessment demonstrated a lower collagen and higher elastin content after first and multiple deliveries. CONCLUSION: The changes in the ovine vaginal wall during representative moments of her lifespan parallel those observed in women.

First delivery and ovariectomy affect biomechanical and structural properties of the vagina in the ovine model.

INTRODUCTION AND HYPOTHESIS: Animal models are useful for investigating the genesis of pelvic floor dysfunction and for developing novel therapies for its treatment. There is a need for an alternative large-animal model to the nonhuman primate. Therefore we studied the effects of the first vaginal delivery, ovariectomy and systemic hormonal replacement therapy (HRT) on the biomechanical and structural properties of the ovine vagina. METHODS: We examined the gross anatomical properties of nulliparous, primiparous, ovariectomized multiparous, and ovariectomized hormone-replaced multiparous sheep (six animals per group). We also harvested mid-vaginal and distal vaginal tissue to determine smooth muscle contractility and passive biomechanical properties, for morphometric assessment of the vaginal wall layers, to determine collagen and elastin content, and for immunostaining for α-smooth muscle actin and estrogen receptor-α. RESULTS: There were no regional differences in the nulliparous vagina. One year after the first vaginal delivery, stiffness and contractility of the distal vagina were decreased, whereas the elastin content increased. The mid-vagina of ovariectomized sheep was stiff, and its epithelium was thin and lacked glycogen. HRT decreased the stiffness of the mid-vagina by 45% but had no measurable effect on contractility or elastin content, and increased epithelial thickness and glycogen content. HRT also increased the epithelial thickness and glycogen content of the distal vagina. At this location, there were no changes in morphology or stiffness. CONCLUSION: In sheep, life events including delivery and ovariectomy affect the biomechanical properties of the vagina in a region-specific way. Vaginal delivery mainly affects the distal region by decreasing stiffness and contractility. HRT can reverse the increase in stiffness of the mid-vagina observed after surgical induction of menopause. These observations are in line with scanty biomechanical measurements in comparable clinical specimens.

Transvaginal Mesh Insertion in the Ovine Model.

This protocol describes mesh insertion into the rectovaginal septum in sheep using a single vaginal incision technique, with and without the trocar-guided insertion of anchoring arms. Parous sheep underwent the dissection of the rectovaginal septum, followed by the insertion of an implant with or without four anchoring arms, both designed to fit the ovine anatomy. The anchoring arms were put in place using a trocar and an "outside-in" technique. The cranial arms were passed through the obturator, gracilis, and adductor magnus muscles. The caudal arms were fixed near the sacrotuberous ligament, through the coccygeus muscles. This technique allows for the mimicking of surgical procedures performed in women suffering from pelvic organ prolapse. The anatomical spaces and elements are easily identified. The most critical part of the procedure is the insertion of the cranial trocar, which can easily penetrate the peritoneal cavity or the surrounding pelvic organs. This can be avoided by a more extensive retroperitoneal dissection and by guiding the trocar more laterally. This approach is designed only for experimental testing of novel implants in large animal models, as trocar-guided insertion is currently not used clinically.

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

PURPOSE: Electrospun 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. METHODS: First 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. RESULTS: Dry 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. CONCLUSION: Abdominal wall reconstruction with electrospun UPy-PCL mesh does not compromise physiologic tissue biomechanical properties, yet provokes a vivid inflammatory reaction.

Comparative Anatomy of the Ovine and Female Pelvis.

BACKGROUND: Pelvic organ prolapse affects half of vaginally parous women. Several animal models are used to study its pathophysiology and treatment. Sheep are interesting because they develop spontaneously prolapse with similar risk factors as women and can be used for vaginal surgery. This study describes ovine pelvis anatomy and compares it to women's pelvis to provide anatomical tools for translational researchers. METHODS: MRI, pelvic dissections, and histology were used for detailed macro- and microscopic analysis of relevant anatomical structures in 6 nulliparous ewes. RESULTS: Although sheep are quadrupeds, the gross and microscopic anatomies are similar to the female pelvis. Principal differences are the shape and its orientation, the absence of the sacrospinous ligament and the internal obturator. The levator ani (except for the puborectalis) and the coccygeus muscle are present, yet the latter is more developed - coinciding with the tail. The dimensions and morphology of the ovine vagina is comparable. The retropubic and the rectovaginal space are accessible transvaginally. There is a wide expression of estrogen receptors with low or absent immunoreactivity in the urethral epithelium, bladder, anus and internal anal sphincter. CONCLUSION: The ovine pelvic floor has many anatomical and ultrastructural similarities to the female pelvic floor.

Finite element model focused on stress distribution in the levator ani muscle during vaginal delivery.

INTRODUCTION AND HYPOTHESIS: During vaginal delivery, the levator ani muscle (LAM) undergoes severe deformation. This stress can lead to stretch-related LAM injuries. The objective of this study was to develop a sophisticated MRI-based model to simulate changes in the LAM during vaginal delivery. METHODS: A 3D finite element model of the female pelvic floor and fetal head was developed. The model geometry was based on MRI data from a nulliparous woman and 1-day-old neonate. Material parameters were estimated using uniaxial test data from the literature and by least-square minimization method. The boundary conditions reflected all anatomical constraints and supports. A simulation of vaginal delivery with regard to the cardinal movements of labor was then performed. RESULTS: The mean stress values in the iliococcygeus portion of the LAM during fetal head extension were 4.91-7.93 MPa. The highest stress values were induced in the pubovisceral and puborectal LAM portions (mean 27.46 MPa) at the outset of fetal head extension. The last LAM subdivision engaged in the changes in stress was the posteromedial section of the puborectal muscle. The mean stress values were 16.89 MPa at the end of fetal head extension. The LAM was elongated by nearly 2.5 times from its initial resting position. CONCLUSIONS: The cardinal movements of labor significantly affect the subsequent heterogeneous stress distribution in the LAM. The absolute stress values were highest in portions of the muscle that arise from the pubic bone. These areas are at the highest risk for muscle injuries with long-term complications.

Tissue response to collagen containing polypropylene meshes in an ovine vaginal repair model.

UNLABELLED: Pelvic Organ Prolapse (POP) is the herniation of pelvic organs into the vagina. Despite broad acceptance of mesh use in POP surgical repair, the complication rate is unacceptable. We hypothesized that collagen-containing polypropylene (PP) mesh types could modulate mesh-tissue integration and reduce long-term inflammation, thereby reducing mesh-associated complications. This study compared the long-term tissue response to an unmodified PP mesh and two collagen containing meshes in an ovine model which has similar pelvic anatomy and vaginal size to human. Three commercially available macroporous PP meshes, uncoated PP mesh (Avaulta Solo) (PP), the same textile PP mesh layered with a sheet of cross-linked porcine acellular matrix (Avaulta Plus) (PP-ACM) and a different yet also macroporous PP (Sofradim) mesh coated with solubilized atelocollagen (Ugytex) (PP-sCOL) were implanted in the ovine vagina and tissue explanted after 60 and 180days. The macrophage phenotype and response to implanted meshes, and vascularity were quantified by immunostaining and morphometry. We quantified changes in extracellular matrix composition biochemically and collagen organisation and percentage area around the interface of the mesh implants by Sirius Red birefringence and morphometry. PP-ACM induced a more sustained inflammatory response, indicated by similar CD45(+) leukocytes but reduced CD163(+) M2 macrophages at 60days (P<0.05). PP-sCOL increased Von Willebrand Factor (vWF)-immunoreactive vessel profiles after 60days. At the micro-molecular level, collagen birefringence quantification revealed significantly fewer mature collagen fibrils (red, thick fibrils) at the mesh-tissue interface than control tissue for all mesh types (P<0.001) but still significantly greater than the proportion of immature (green thin fibrils) at 60days (P<0.05). The proportion of mature collagen fibrils increased with time around the mesh filaments, particularly those containing collagen. The total collagen percent area at the mesh interface was greatest around the PP-ACM mesh at 60days (P<0.05). By 180days the total mature and immature collagen fibres at the interface of the mesh filaments resembled that of native tissue. In particular, these results suggest that both meshes containing collagen evoke different types of tissue responses at different times during the healing response yet both ultimately lead to physiological tissue formation approaching that of normal tissue. STATEMENT OF SIGNIFICANCE: Pelvic organ prolapse (POP) is the descent of the pelvic organs to the vagina. POP affects more than 25% of all women and the lifetime risk of undergoing POP surgery is 19%. Although synthetic polypropylene (PP) meshes have improved the outcome of the surgical treatment for POP, there was an unacceptable rate of adverse events including mesh exposure and contracture. It is hypothesized that coating the PP meshes with collagen would provide a protective effect by preventing severe mesh adhesions to the wound, resulting in a better controlled initial inflammatory response, and diminished risk of exposure. In this study we assessed the effect of two collagen-containing PP meshes on the long-term vaginal tissue response using new techniques to quantify these tissue responses.

Evaluating Alternative Materials for the Treatment of Stress Urinary Incontinence and Pelvic Organ Prolapse: A Comparison of the In Vivo Response to Meshes Implanted in Rabbits.

PURPOSE: Serious complications can develop with the mesh implants used for stress urinary incontinence and pelvic organ prolapse surgery. We evaluated 2 materials currently in clinical use and 2 alternative materials using a rabbit abdominal model to assess host response and biomechanical properties of the materials before and after implantation. MATERIALS AND METHODS: Poly-L-lactic acid and polyurethane meshes were electrospun to be compared to commercially available polypropylene and polyvinylidene fluoride meshes. A total of 40 immunocompetent full-thickness abdominal wall defect rabbit models were used, including 8 in each of the poly-L-lactic acid, polyurethane, polyvinylidene fluoride and polypropylene experimental groups, and sham controls. Two 20 mm defects were created per animal and primarily repaired. The experimental groups then underwent onlay of each repair material while sham controls did not. Four rabbits per group were sacrificed at days 30 and 90. Abdominal wall specimens containing the defect with or without repair material were explanted to be assessed by histology (hematoxylin and eosin staining, and immunohistochemistry) and biomechanical testing at 30 and 90 days. RESULTS: At 90 days of implantation tissues repaired with all 4 materials showed biomechanical properties without significant differences. However, polypropylene and polyvinylidene fluoride meshes demonstrated a sustained chronic inflammatory response profile by 90 days. In contrast, poly-L-lactic acid and polyurethane meshes integrated well into host tissues with a decreased inflammatory response, indicative of constructive remodeling. CONCLUSIONS: Poly-L-lactic acid and polyurethane alternative materials achieved better host integration in rabbit models than current synthetic repair materials.

Immediate postoperative changes in synthetic meshes - In vivo measurements.

BACKGROUND AND OBJECTIVE: Immediate post-operative structural changes in implanted synthetic meshes are believed to contribute to graft related complications. Our aim was to observe in vivo dimensional changes at the pore level. METHOD: Two different polyvinylidine fluoride (PVDF) meshes, CICAT and ENDOLAP (Dynamesh, FEG Textiltechnik) were implanted in 18 female Sprague Dawley (n=9/group). The meshes (30×25mm(2)) were overlaid on a full thickness incision (2×1cm(2)) and sutured on the abdominal wall. All animals underwent microCT imaging (res. 35µm/px) at day 1 and 15 postsurgery. A customized procedure was developed to semi-automatically detect the pore centers from the microCT dataset. Horizontal (transverse) and vertical (cranio-caudal) inter-pore distances were then recorded. The overall mesh dimensions were also noted from 3D models generated from in vivo microCT datasets. Inter-pore distances and the overall dimensions from microCT images of the meshes set in agarose gel phantom were used as controls. Mann-Whitney U test was done to check for significant differences. RESULTS: Number of measurable vertical and horizontal inter-pore distances was 56.5(10.5) and 54.5(14.5) [median (IQR)] per animal. At day 1, we observed a 4.3% (CICAT) and 4.6% (ENDOLAP) increase in vertical inter-pore distance when compared to controls (p<0.001, p=0.003, respectively). Measurements fell back to phantom values by day 15 (3.7% and 4.9% decrease compared to day 1, p<0.001 for both). The horizontal inter-pore distances for ENDOLAP increased by 1.4% (p=0.003) during the two weeks period. The overall mesh dimensions did not change significantly day 1 and day 15. The in vivo measurement of the overall mesh dimensions demonstrated a 15.9% reduction in mesh area as compared to that in phantom controls. CONCLUSION: We report for the first time, in vivo changes in pore dimensions of a textile implant. This study clearly demonstrates the dynamic nature of a textile implant during the tissue integration process. For studied PVDF meshes, the process of tissue integration leads to limited but significant reduction over time as observed at the pore level. Remarkably the extent of this reduction does not account for the change in overall mesh dimensions.

Cross-linked xenogenic collagen implantation in the sheep model for vaginal surgery.

The properties of meshes used in reconstructive surgery affect the host response and biomechanical characteristics of the grafted tissue. Whereas durable synthetics induce a chronic inflammation, biological grafts are usually considered as more biocompatible. The location of implantation is another determinant of the host response: the vagina is a different environment with specific function and anatomy. Herein, we evaluated a cross-linked acellular collagen matrix (ACM), pretreated by the anti-calcification procedure ADAPT® in a sheep model for vaginal surgery. Ten sheep were implanted with a cross-linked ACM, and six controls were implanted with a polypropylene (PP; 56 g/m2) control. One implant was inserted in the lower rectovaginal septum, and one was used for abdominal wall defect reconstruction. Grafts were removed after 180 days; all graft-related complications were recorded, and explants underwent bi-axial tensiometry and contractility testing. Half of ACM-implanted animals had palpable induration in the vaginal implantation area, two of these also on the abdominal implant. One animal had a vaginal exposure. Vaginal ACMs were 63 % less stiff compared to abdominal ACM explants (p = 0.01) but comparable to vaginal PP explants. Seven anterior vaginal ACM explants showed areas of graft degradation on histology. There was no overall difference in vaginal contractility. Considering histologic degradation in the anterior vaginal implant as representative for the host, posterior ACM explants of animals with degradation had a 60 % reduced contractility as compared to PP (p = 0.048). Three abdominal implants showed histologic degradation; those were more compliant than non-degraded implants. Vaginal implantation with ACM was associated with graft-related complications (GRCs) and biomechanical properties comparable to PP. Partially degraded ACM had a decreased vaginal contractility.

Three-dimensional analysis of implanted magnetic-resonance-visible meshes.

OBJECTIVE: Our primary objective was to develop relevant algorithms for quantification of mesh position and 3D shape in magnetic resonance (MR) images. METHODS: In this proof-of-principle study, one patient with severe anterior vaginal wall prolapse was implanted with an MR-visible mesh. High-resolution MR images of the pelvis were acquired 6 weeks and 8 months postsurgery. 3D models were created using semiautomatic segmentation techniques. Conformational changes were recorded quantitatively using part-comparison analysis. An ellipticity measure is proposed to record longitudinal conformational changes in the mesh arms. The surface that is the effective reinforcement provided by the mesh is calculated using a novel methodology. The area of this surface is the effective support area (ESA). RESULTS: MR-visible mesh was clearly outlined in the images, which allowed us to longitudinally quantify mesh configuration between 6 weeks and 8 months after implantation. No significant changes were found in mesh position, effective support area, conformation of the mesh's main body, and arm length during the period of observation. Ellipticity profiles show longitudinal conformational changes in posterior arms. CONCLUSIONS: This paper proposes novel methodologies for a systematic 3D assessment of the position and morphology of MR-visible meshes. A novel semiautomatic tool was developed to calculate the effective area of support provided by the mesh, a potentially clinically important parameter.

Host reaction to vaginally inserted collagen containing polypropylene implants in sheep.

OBJECTIVE: 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. STUDY DESIGN: 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. RESULTS: 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. CONCLUSION: 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.