Light-Activated Chemically Reactive Fibrous Patch Revolutionizes Wound Repair Through the Prevention of Postoperative Adhesion.

A light-activated chemically reactive fibrous patch (ChemPatch) with tissue adhesion and wound healing activity was developed for preventing postoperative peritoneal adhesion. ChemPatch was constructed by an integrative electrospinning fabrication strategy, generating multifunctional PCL-NHS fibers encapsulating antioxidant curcumin and MnO2 nanoparticles. ChemPatch exhibited excellent photothermal conversion, which not only reformed the physical state to match the tissue but also improved conjugation between ChemPatch and tissues, allowing for strong attachment. Importantly, ChemPatch possessed good antioxidant and radical scavenging activity, which protected cells in an oxidative microenvironment and improved tissue regeneration. Particularly, ChemPatch acted as a multifunctional barrier and could not only promote reepithelialization and revascularization in wound defect model but simultaneously ameliorate inflammation and prevent postoperative peritoneal adhesion in a mouse cecal defect model. Thus, ChemPatch represents a dual-active bioadhesive barrier for reducing the incidence and severity of peritoneal adhesions.

Vaginal Patch Plastron for cystocele repair at the time of vaginal prosthesis bashing: A technical note (with video).

Native tissue cystocele repair has been the cornerstone of prolapse surgery, especially since the learned societies warned clinicians and patients about serious mesh related complications and recommend a vaginal route without prosthesis in first intention. Surgical techniques mainly consist in anterior colporraphy, vaginal patch plastron and para vaginal repair. However, in case of vaginal patch plastron, the vagina left in contact with the bladder is a material of much better quality than colporraphy alone. The multiplication of native tissues, generating post-operative fibrosis, associated with anchorage on a strong ligamentous structure, allows to expect better outcomes compared to anterior colporraphy. Indeed, vaginal plastron corrects median cystoceles with a vaginal strip as well as lateral cystoceles thanks to bilateral paravaginal suspension. Thereby, vaginal patch plastron appears to be a good compromise between the 3 autologous techniques with median and paralateral repair We aimed to describe the surgical technique of the vaginal patch plastron for vaginal native tissue repair for cystocele.

A novel anatomic titanium mesh cage for reducing the subsidence rate after anterior cervical corpectomy: a finite element study.

Fusion with a titanium mesh cage (TMC) has become popular as a conventional method after cervical anterior corpectomy, but postoperative TMC subsidence has often been reported in the literature. We designed a novel anatomic cervical TMC to reduce the postoperative subsidence rate. According to the test process specified in the American Society of Testing Materials (ASTM) F2267 standard, three-dimensional finite element analysis was used to compare the anti-subsidence characteristics of a traditional TMC (TTMC) and novel TMC (NTMC). Through analysis, the relative propensity values of a device to subside (Kp) of the TTMC and NTMC were 665.5 N/mm and 1007.2 N/mm, respectively. A higher Kp measurement is generally expected to indicate that the device is more resistant to subsidence into a vertebral body. The results showed that the novel anatomic titanium mesh cage (NTMC) significantly improved the anti-subsidence performance after anterior cervical corpectomy and fusion (ACCF), which was approximately 51.3% higher than that of the traditional titanium mesh cage.

Five-year outcomes of an anterior mesh kit for severe pelvic organ prolapse in women.

AIMS: The Elevate™ Anterior mesh was designed to correct anterior vaginal wall defects by providing level 1 and 2 support via a single incision and transvaginal approach. This study aimed to examine the objective and subjective outcomes following prolapse repair using the Elevate™ Anterior mesh kit. METHODS: A retrospective case series review of 270 patients with Baden-Walker Grades 3 or 4 anterior compartment prolapse who underwent the Elevate™ Anterior mesh kit was undertaken. Operative complications were recorded with follow-up intervals arranged at 1, 6, 12, 24, 36, 48 and 60 months. A standardized questionnaire directed at urinary, pain and recurrence symptoms was used at each follow-up visit. Pelvic examinations were performed at each follow-up visit to assess for objective cure and for detection of complications. The primary outcome was to assess the cure rate defined as anterior vaginal wall prolapse ≤ Grade 1. RESULTS: The follow-up rate was 28.9%. Subjective and objective cure rates at 60 months were 100% and 96.2%, respectively. Ten (3.7%) intraoperative complications were recorded. At 60 months, three (3.8%) patients complained of de novo stress/urge urinary incontinence. One patient had dyspareunia at 6 months postsurgery which resolved by the end of 1 year. Prolapse recurrences in the anterior compartment was 3.8% at the end of 5 years. Mesh exposure into the vagina occurred in three patients. CONCLUSIONS: In conclusion, our experience with the Elevate™ Anterior mesh kit had promising subjective and objective outcomes with high patient satisfaction rates.

Comparative analyses of attitude, knowledge, and recollection of preoperative counseling regarding pelvic mesh among women with or without a mesh-related complication.

PURPOSE: Our objective was to compare the recollection of preoperative counseling regarding mesh for pelvic organ prolapse (POP) and/or stress urinary incontinence (SUI) among women with or without a mesh-related complication (MRC). We hypothesized that the patients who had MRC would better recollect counseling regarding complications associated with mesh. METHODS: We conducted a retrospective cohort study among women who had prior implantation of synthetic, non-absorbable mesh for POP and/or SUI at least 3 months prior who presented with or without a MRC. The primary outcome was the proportion of women who recalled being counseled preoperatively about the risk of mesh exposure. RESULTS: Ninety-six women were included in the final analysis (50 MRC; 46 no MRC). MRC women presented further in time from the index surgery [median 69 months [IQR 26-115] vs 12 months (IQR 6-64), p < 0.01]. After adjustment for time since surgery and age, MRC women were significantly less likely to recall being counseled about the possibility of any MRC [19/50 (38%) vs 32/44 (73%), aOR 0.29, 95% CI 0.11-0.79, p = 0.01]. They were also less likely to report they would undergo the same surgery again 5-point Likert scale [median 3 (IQR 1-4) vs 5 (IQR 3-5), 5-point Likert scale, p < 0.01], less satisfied with their mesh surgery [median 1 (IQR 1-3) vs 5 (IQR 3-5), 5-point Likert scale, p < 0.01] and recommended improved preoperative counseling [27/50 (54%) vs 6/46 (13%), p < 0.01]. CONCLUSION: Women who experienced MRC were less likely to recall being counseled about the possibility of MRC and report more unmet needs regarding perioperative counseling than women without MRC.

Inaccuracies in News Media Reporting About the 2019 US Food and Drug Administration Ban on Transvaginal Mesh for Pelvic Organ Prolapse Repair.

OBJECTIVE: To analyze inaccuracies in the news media reporting of the 2019 US Food and Drug Administration (FDA) ban on surgical mesh for transvaginal repair of pelvic organ prolapse (POP). METHODS: We queried the NexisUni media database for English-language news articles about "transvaginal mesh" or "FDA" published before and after the ban. Content analysis was based on discussion of the ban, indications for surgical mesh, and assessment of bias. We characterized public interest in transvaginal mesh using Google Trends. RESULTS: Of 290 news articles reviewed, 42 articles were included for analysis. Public interest in transvaginal mesh increased 4-fold after the FDA announcement. While 15 articles (38%) accurately reported that mesh was used in both POP and incontinence repairs, a plurality (18, 43%) only described using mesh for POP. The majority (30, 71%) of articles did not specify that the FDA ban applied to only transvaginal repair of POP and not to incontinence. Despite multiple professional societies affirming the use of mesh for incontinence, only 2 (5%) articles cited these evidence-based recommendations. About half of the articles had an overtly biased tone; articles with an anti-mesh bias were significantly less likely to identify the mesh indications relevant to the ban (P <.01). CONCLUSION: Seventy percent of news reports about the 2019 FDA ban on transvaginal mesh for POP failed to distinguish between the clinical indications for mesh impacted by the ban. The findings raise concern about patient perceptions of and future access to mesh surgery, regardless of indication.

A preliminary evaluation of two different meshes in minimally invasive inguinal hernia surgery.

BACKGROUND: Many meshes are available for use in laparoscopic inguinal hernia repair. The surgeon must consider several factors when choosing a mesh for hernia repair including clinical outcomes, cost, and ease of use. The purpose of this study was to compare two different lightweight polypropylene meshes for laparoscopic and robotic inguinal hernia repairs. METHODS: Subjects were randomized immediately before surgery. Data were reported in N (%) and median [Q1-Q3], comparisons of mesh insertion time were tested using a 2 × 2 ANOVA on the ranked times, comparisons between categorical variables were tested with Fisher's Exact, and all data were analyzed using SAS® 9.4 (SAS Institute, Inc.). RESULTS: Between January 2015 and June 2016, 50 subjects were enrolled; two were excluded. Of 48 eligible subjects, most were Caucasian (N = 42, 88%), male (N = 37, 77%), with a median age of 63, and were randomized evenly between 3DMax™ mesh and Ultrapro® mesh. Robotic mesh placement significantly increased insertion time regardless of mesh type (p < .0001). When comparing NASA-TLX self-assessment surveys, there was no significant difference between the meshes in difficulty of placement. The type of mesh did not significantly impact the insertion time regardless of robot use (p = 0.523). CONCLUSION: Our data demonstrate that mesh insertion times comparing two different lightweight polypropylene meshes were not significantly different. Increased insertion times associated with robotic repair are likely due to the mechanics of robotic suturing and associated learning curve. Our data suggest that these meshes can be used interchangeably based on the surgeon's preference. CLINICAL TRIAL REGISTRATION NUMBER: NCT01825187.

Implantation of biologic mesh in ventral hernia repair-does it make sense?

BACKGROUND: Biological acellular porcine dermis mesh, such as Permacol™, has been used since 2009 to treat abdominal incisional hernias in a septic context. This study investigated the risk factors for incisional hernia recurrence after biological mesh augmentation. RESULTS: Over a period of 6 years from February 2009 to February 2015, 68 patients underwent surgery. The mesh was placed intraperitoneally with closure of the anterior fascia in 27 cases (39.7%). The biological mesh was placed in the retromuscular pre-fascial plane in 1 case (1.5%) and pre-aponeurotic plane in 1 case (1.5%). Closure of the anterior fascia was not achieved in 39 cases, including 20 cases in which the mesh was placed intraperitoneally (intraperitoneal bridging group, 29.4%) and 19 cases in which the mesh was placed between the edges of the fascia (inlay bridging group, 27.9%). There were 37 cases of postoperative surgical site infections (54.4%), and Clavien-Dindo morbidity staging indicated stage I-II and III-IV complications in 19.1% and 44.1% of the cases, respectively. The recurrence rate was 61.8%, and the mortality rate was 0%. The rate of recurrence was significantly lower in the «fascia approximated¼ group (37%), p = 0.001). Univariate analyses of risk factors for procedural failure indicated an increased risk of recurrence in cases of postoperative surgical site infections, complications of Clavien-Dindo grade III or higher, an absent fascial closure in front of the mesh (OR = 8.69), an operating time longer than 180 min, and a VHWG score higher than 2. After logistic regression, the risk factors for recurrence were postoperative infections (OR = 6.2), placement of bridged biological mesh (OR = 22.3), and postoperative morbidity grade III or higher (OR = 16.7). CONCLUSIONS: Patients with postoperative surgical site infections are at an increased risk for recurrence, and bridged mesh placements lack efficacy. Overall, this study challenges the purported advantage of biologics in treating incisional hernia repairs.

Comparison of the Efficiency of Two Novel Guided Bone Regeneration Devices in the Rabbit Calvarial Model.

BACKGROUND: Creating a secluded large space using guided bone regeneration (GBR) is a novel osteogenesis technique used in the prevention of premature membrane exposure complications. However, this technique is not considered clinically feasible. OBJECTIVES: This study aimed to compare the outcome of the insertion of two novel GBR devices in a rabbit calvarial model in terms of mode of action, simplicity, and amount of new space and bone gained. MATERIALS AND METHODS: The expansible GBR (EGBR) device, composed mainly of a titanium plate, silicone membrane, and activation screw, was inserted beneath the periosteum in the calvarial area of eight rabbits. The smart GBR (SGBR) device, composed of silicone sheets and Nitinol strips, were inserted beneath the periosteum in the calvarial area of another 10 rabbits. Half of each group was sacrificed 2 months after surgery, and the other half was sacrificed after 4 months. RESULTS: Histological and microradiographical analysis showed that, at 2 months, the EGBR device achieved a mean space gain of 207.2 mm3, a mean bone volume of 68.2 mm3, and a mean maximum bone height of 1.9 mm. Values for the same parameters at 4 months were 202.1 mm3, 70.3 mm3, and 1.6 mm, respectively. The SGBR device had significantly higher (P < 0.05) mean space gain (238.2 mm3; 239.5 mm3), bone volume (112.9 mm3, 107.7 mm3), and bone height (2.7 mm; 2.6 mm) than the EGBR device at 2 and 4 months, respectively. CONCLUSION: Both devices proved to be effective in augmenting bone vertically through the application of GBR and soft tissue expansion processes. However, the SGBR device was more efficient in terms of mode of action, simplicity, and amount of bone created in the new space.

Tissue remodeling macrophages morphologically dominate at the interface of polypropylene surgical meshes in the human abdomen.

BACKGROUND: Mesh implants are widely used to reinforce the abdominal wall, although the inevitable inflammatory foreign body reaction (FBR) at the interface leads to complications. Macrophages are suspected to regulate the subsequent scar formation, but it is still unclear whether adequate fibrous scar formation with collagen deposition depends mainly on the presence of M1 or M2 macrophages. METHODS: This study investigated the FBR to seven human polypropylene meshes, which were removed after a median incorporation time of 1 year due to the primary complaint of recurrence. Using immunofluorescence, the FBR was examined in six regional zones with increasing distance from the mesh fibers up to 350 µm, based on the cell densities, macrophage M1 (CD86) and M2 (CD163, CD206) phenotypes, deposition of collagen-I and -III, and expression of matrix metalloproteinase-2 (MMP-2) and -8 as indicator of collagen degradation. RESULTS: All mesh-tissue complexes demonstrated a decrease in cell density and macrophages with distance to the mesh fibers. Overall, about 60% of the macrophages presented an M2 phenotype, whereas only 6% an M1 phenotype. Over 70% of macrophages showed co-expression with collagen-I or -III and over 50% with MMP-2. CONCLUSIONS: The chronic FBR to polypropylene meshes is associated with an M2 macrophage response, which is accompanied by collagen deposition and MMP-2 expression. These findings challenge the idea that mainly M1 macrophages are related to inflammation and highlights that iatrogenic attempts to polarize these cells towards the M2 phenotype may not be a solution to ameliorate the long-term foreign body reaction.

Consenso de la Asociación Española de Urología sobre el uso de mallas en la cirugía del prolapso de órganos pélvicos / Consensus statement of the Spanish Association Of Urology on the use of meshes in pelvic organ prolapse

INTRODUCCIÓN: Recientemente la Food and Drug Administration ha prohibido el uso de mallas transvaginales para el tratamiento quirúrgico de los prolapsos de órganos pélvicos (POP) en Estados Unidos. Esto ha suscitado una repercusión a escala mundial en el manejo de la patología del suelo pélvico por parte de los diferentes especialistas. OBJETIVO: Lograr un consenso sobre el uso de mallas en el tratamiento quirúrgico de los POP. ADQUISICIÓN DE DATOS/EVIDENCIA: Se organizó un Comité de expertos de la Asociación Española de Urología (AEU) para una revisión de la literatura y analizar la seguridad y eficacia del uso de mallas de polipropileno en la cirugía de los POP. RESULTADOS/EVIDENCIA DE LA LITERATURA: La evidencia refleja que el uso de mallas, comparado con el uso de tejidos nativos, ofrece una mejor eficacia a expensas de nuevas complicaciones y una mayor tasa de revisiones quirúrgicas, siendo estas menores en manos de cirujanos expertos. CONCLUSIONES: La cirugía del POP debe ser realizada por cirujanos con experiencia, adecuadamente formados y en centros de referencia. El paciente debe recibir una información correcta acerca de las diferentes opciones de tratamiento. Las mallas transvaginales solo deben indicarse en casos complejos y en recidivas tras cirugía del POP. PROPUESTA AEU: Creación de una guía clínica y de un registro nacional para la evaluación a largo plazo. Elaboración de un Consentimiento Informado a disposición de todos los profesionales y pacientes, así como un plan de formación específico para conseguir una mejor capacitación en la cirugía compleja del suelo pélvico

INTRODUCTION: Recently the Food and Drug Administration has banned the use of transvaginal meshes for the surgical treatment of pelvic organ prolapse (POP) in the United States. This has caused a worldwide impact on the management of pelvic floor pathology by different specialists. OBJECTIVE: To achieve a consensus on the use of meshes in the surgical treatment of POPs. ACQUISITION OF DATA/EVIDENCE: A Committee of experts of the Spanish Association of Urology (AEU) was organized to review the literature and analyze the safety and efficacy of the use of polypropylene meshes in POP surgery. RESULTS/EVIDENCE FROM THE LITERATURE: The evidence reflects that the use of meshes, compared to the use of native tissues, offers better efficacy at the expense of new complications and a higher rate of surgical reviews, these being minor in the hands of expert surgeons. CONCLUSIONS: POP surgery must be performed by experienced surgeons, properly trained and in referral centers. The patient should receive correct information about the different treatment options. Transvaginal meshes should only be indicated in complex cases and in recurrences after POP surgery. AEU PROPOSAL: Creation of a clinical guideline and a national registry for long-term evaluation. Preparation of an Informed Consent available to all professionals and patients, as well as a specific training plan to achieve better training in complex pelvic floor surgery

Alterations in the mechanical, chemical and biocompatibility properties of low-cost polyethylene and polyester meshes after steam sterilization.

INTRODUCTION: In Africa and other Low Resource Settings (LRS), the guideline-based and thus in most cases mesh-based treatment of inguinal hernias is only feasible to a very limited extent. This has led to an increased use of low cost meshes (LCMs, mostly mosquito meshes) for patients in LRS. Most of the LCMs used are made of polyethylene or polyester, which must be sterilized before use. The aim of our investigations was to determine changes in the biocompatibility of fibroblasts as well as mechanical and chemical properties of LCMs after steam sterilization. MATERIAL AND METHODS: Two large-pored LCMs made of polyester and polyethylene in a size of 11 x 6 cm were cut and steam sterilized at 100, 121 and 134 °C. These probes and non-sterile meshes were then subjected to mechanical tensile tests in vertical and horizontal tension, chemical analyses and biocompatibility tests with human fibroblasts. All meshes were examined by stereomicroscopy, scanning electron microscopy (SEM), LDH (cytotoxicity) measurement, viability testing, pH, lactate and glycolysis determination. RESULTS: Even macroscopically, polyethylene LCMs showed massive shrinkage after steam sterilization, especially at 121 and 134 °C. While polyester meshes showed no significant changes after sterilization with regard to deformation and damage as well as tensile force and stiffness, only the unsterile polyethylene mesh and the mesh sterilized at 100 °C could be tested mechanically due to the shrinkage of the other specimen. For these meshes the tensile forces were about four times higher than for polyester LCMs. Chemical analysis showed that the typical melting point of polyester LCMs was between 254 and 269 °C. Contrary to the specifications, the polyethylene LCM did not consist of low-density polyethylene, but rather high-density polyethylene and therefore had a melting point of 137 °C, so that the marked shrinkage described above occurred. Stereomicroscopy confirmed the shrinkage of polyethylene LCMs already after sterilization at 100 °C in contrast to polyester LCMs. Surprisingly, cytotoxicity (LDH measurement) was lowest for both non-sterile LCMs, while polyethylene LCMs sterilized at 100 and 121 °C in particular showed a significant increase in cytotoxicity 48 hours after incubation with fibroblasts. Glucose metabolism showed no significant changes between sterile and non-sterile polyethylene and polyester LCMs. CONCLUSION: The process of steam sterilization significantly alters mechanical and structural properties of synthetic hernia mesh implants. Our findings do not support a use of low-cost meshes because of their unpredictable properties after steam sterilization.

Impact of human umbilical cord-derived stem cells (HUMSCs) on host responses to a synthetic polypropylene mesh for pelvic floor reconstruction in a rat model.

In order to evaluate the effects of human umbilical cord-derived stem cells (HUMSCs) on the biocompatibility of and tissue response to a polypropylene (PP) mesh (Gynemesh™ PS) implanted in rat vaginas, HUMSCs were isolated and characterized in vitro and then combined with Gynemesh™ PS to create a tissue-engineered mesh. This tissue-engineered mesh and pure PP mesh were implanted in the submucosae of the posterior vaginal walls of rats. Mesh/tissue complexes were harvested at 1, 4 and 12 weeks after implantation. Histological evaluations including an assessment of the inflammatory reaction, neovascularization and fibrosis around the mesh fibers were performed and real-time quantitative polymerase chain reaction (RT-PCR) was used to analyze the mRNA expression of genes involved in wound healing at the tissue-mesh interface. After being seeded onto the PP mesh scaffold, HUMSCs grew and proliferated well in vitro culture. One week after implantation, the HUMSC-seeded mesh elicited a greater inflammatory response than the pure PP mesh (3.33 ± 0.21 vs. 2.63 ± 0.18, p = 0.026), while 4 and 12 weeks after implantation, the inflammatory response in the HUMSC-seeded mesh was lower than that in the unseeded mesh (p < 0.05). At 12 weeks, the HUMSC-seeded mesh induced a lower expression of matrix metalloproteinase (MMP)-1 and a higher expression of anti-inflammatory cytokine interleukin (IL)-4. HUMSCs may decrease the inflammatory response and improve the biocompatibility of a conventional synthetic mesh and may have the potential to reduce postoperative complications such as mesh exposure or erosion.

A new semiresorbable mesh for primary inguinal repair: a preliminary observational study on quality of life and safety.

BACKGROUND: A currently unsolved problem of open inguinal hernia repair (IHR) is chronic postoperative inguinal pain (CPIP), which affects 10-12% of patients after IHR. In the present paper, we explored the results of a newly designed partially absorbable mesh made of polypropylene and polylactic acid (HybridMesh®) for open hernia repair and its impact on postoperative safety, efficacy, comfort and pain. METHODS: A prospective multicentric pilot trial was conducted in third-referral centers across Italy (n = 5). Inclusion criteria were unilateral primary inguinal hernia in patients of both genders and BMI < 30 kg/m2. All patients were submitted to elective Lichtenstein mesh hernia repair under local anesthesia with HybridMesh. Primary outcome measure was the evaluation of Carolina Comfort Scale and modifications at 2 years after surgery and its correlation with surgical variables; secondary outcomes were postoperative early and late morbidity, recurrence and postoperative early quality of life. RESULTS: Between 2015 and 2016, 125 (5 female) patients were operated, 2-year follow-up rate was 100%. The surgical site occurrence rate was 28% without the need of procedural interventions. Twenty-four months after surgery, no case of severe CPIP was recorded and altered global CCS score was present in 16 patients (13.0%). At univariate analysis, CCS score was negatively affected by fixation with sutures (OR 3.949; 95% CI 1.334-13.300), with no effect shown on multivariate analysis. Alterations in pain and movement limitations domains of CCS were observed in 9.7% of patients, at univariate analysis; they occurred more frequently when the mesh was sutured (OR 4.437; 95% CI 1.387-17.025) and in patients suffering from SSO (ecchymosis: OR 3.269; 95% CI 1.032-10.405); however, no effect was shown on multivariate analysis. Two recurrences (1.6%) were identified within the first postoperative year. CONCLUSIONS: The results of this study support the safety, efficacy and good tolerability of HybridMesh as a device to treat primary unilateral inguinal hernia during open anterior approach. Further studies are needed to clarify its role in comparison to currently available devices at longer follow-ups.

Analysis of resorbable mesh implants in short-term human muscular fascia cultures: a pilot study.

PURPOSE: Alteration in fascial tissue collagen composition represents a key factor in hernia etiology and recurrence. Both resorbable and non-resorbable meshes for hernia repair are currently used in the surgical setting. However, no study has investigated so far the role of different implant materials on collagen deposition and tissue remodeling in human fascia. The aim of the present study was to develop a novel ex vivo model of human soft tissue repair mesh implant, and to test its suitability to investigate the effects of different materials on tissue remodeling and collagen composition. METHODS: Resorbable poly-4-hydroxybutyrate and non-resorbable polypropylene mesh implants were embedded in human abdominal fascia samples, mimicking common surgical procedures. Calcein-AM/Propidium Iodide vital staining was used to assess tissue vitality. Tissue morphology was evaluated using Mallory trichrome and hematoxylin and eosin staining. Collagen type I and III expression was determined through immunostaining semi-quantification by color deconvolution. All analyses were performed after 54 days of culture. RESULTS: The established ex vivo model showed good viability at 54 days of culture, confirming both culture method feasibility and implants biocompatibility. Both mesh implants induced a disorganization of collagen fibers pattern. A statistically significantly higher collagen I/III ratio was detected in fascial tissue samples cultured with resorbable implants compared to either non-resorbable implants or meshes-free controls. CONCLUSION: We developed a novel ex vivo model and provided evidence that resorbable polyhydroxybutyrate meshes display better biomechanical properties suitable for proper restoration in surgical hernia repair.

Does primary closure of direct inguinal hernia defect during laparoscopic mesh repair reduce the risk of early recurrence?

PURPOSE: Hernia recurrence is an important complication following inguinal hernia repair. Primary closure of ventral hernia defects laparoscopically has been shown to reduce the risk of recurrence and seroma formation. The results for ventral hernias may potentially be applied to direct inguinal hernias. Our aim was to evaluate the value of primary closure of direct defects during laparoscopic inguinal hernia mesh repair in reducing the incidence of early recurrence. METHODS: A retrospective, single-center cohort study was conducted on cases performed from August 2016 to February 2018. Patients with direct inguinal hernias undergoing elective laparoscopic mesh repair were included. When performed, the direct hernia defect was primarily closed with extracorporeal non-absorbable interrupted sutures followed by standard placement of a lightweight mesh covering myopectineal orifices. Early recurrence was defined as occurring within 1 year of surgery. RESULTS: A total of 75 direct inguinal hernias in 53 patients who underwent surgery and completed at least 1 year of follow-up were analyzed. The mean age of patients was 63 years (range 44-82 years); with majority of patients being male (98.1%). There were no significant differences observed between the two patient populations in terms of demographics, mean operative time and risk factors. In 9 (16.9%) patients, the direct hernias were recurrent hernias and all underwent open mesh repair during the index hernia surgery. The majority of hernia repairs (63 hernias in 45 patients, 85%) were performed via the totally extraperitoneal (TEP) approach. 19 patients (35.8%) with 28 direct inguinal hernias underwent primary closure of the direct defect prior to mesh placement; while, 34 patients (64.2%) with 47 direct hernias did not undergo primary closure. There were 3 direct hernia recurrences (6.4%) at 1 year post-operatively, and all occurred in the non-closure group. In comparison, there were no recurrences in the closure group; however, this difference was not statistically significant (p = 0.289) in our study due to the small sample size. CONCLUSION: Closure of direct inguinal hernia defects during laparoscopic mesh repair has been shown to reduce the incidence of early hernia recurrence in our retrospective study but future randomized controlled trials with large numbers would enable us to draw more robust conclusions and perhaps change the way we perform laparoscopic inguinal hernia repair.

Complications Following the Use of Biologic Mesh in Ileostomy Closure: A Retrospective, Comparative Study.

Prophylactic placement of mesh in the abdominal wall during ileostomy closure can decrease the rate of hernia formation. However, few studies have evaluated the safety of biologic mesh in ileostomy closure. PURPOSE: This study aimed to investigate the safety of biologic mesh in ileostomy closure, specifically the need to remove the mesh due to infection. The rate of surgical site infection (SSI), incisional hernia, surgical site occurrence ([SSO] including seroma and hematoma), and wound pain between primary closure and mesh closure groups also were investigated. METHODS: Using a retrospective study design, data from all consecutive patients who underwent ileostomy closure from January 2015 to June 2016 at the Hanyang University Hospital, Seoul, Republic of Korea, were analyzed. Patients with stage IV colorectal cancer, who were older than 85 years, or who experienced intestinal perforation during the procedure were excluded. Demographic (age, sex, body mass index [BMI], underlying disease) and clinical characteristics as well as SSI, SSO, length of hospital stay, use of additional analgesics, white blood cell count, C-reactive protein, and visual analog scale (VAS) pain scores (noted on days 1, 3, 5, and 14) were abstracted and compared. Clinical and surgical variables were compared using the Mann-Whitney U test, the χ2-test, or Fisher's exact test, depending on the nature of the data. RESULTS: Of the 38 patients who underwent ileostomy closure, 33 (18 [54.5%] who received primary closure and 15 [45.5%] who received mesh closure) were included for analysis. Patient, surgical, and clinical characteristics were not significantly different, but the mean age of the primary closure group was significantly higher than that of the mesh closure group (71 ± 9 vs. 62 ± 10 years old; P = .014). The median follow-up duration was 25 months (interquartile range 18.0-31.5 months). Six (6) complications were observed in 5 patients in the primary closure group, and 8 complications in 5 patients were noted in the mesh closure group (27.8% vs. 33.3%; P = 1.000). None of the cases required removal of the biologic mesh due to mesh-related infectious complication. Two (2) SSIs occurred in the primary closure group (11.1% vs. 0%; P = .489). Three (3) patients experienced a postoperative incisional hernia (9.1%) - 1 in the primary closure group and 2 in the mesh closure group (5.6% vs. 13.3%; P = .579). No statistically significant differences in pain or length of hospitalization were noted. CONCLUSION: No mesh-related infectious complications required biologic mesh removal, and no significant differences were noted in SSI, incisional hernia, and wound pain between the primary closure and mesh closure groups. Although not significantly different, the higher rates of hernia and SSOs in the mesh group require further study.

Mesh smoothing algorithm based on exterior angles split.

Since meshes of poor quality give rise to low accuracy in finite element analysis and kinds of inconveniences in many other applications, mesh smoothing is widely used as an essential technique for the improvement of mesh quality. With respect to this issue, the main contribution of this paper is that a novel mesh smoothing method based on an exterior-angle-split process is proposed. The proposed method contains three main stages: the first stage is independent element geometric transformation performed by exterior-angle-split operations, treating elements unconnected; the second stage is to offset scaling and displacement induced by element transformation; the third stage is to determine the final positions of nodes with a weighted strategy. Theoretical proof describes the regularity of this method and many numerical experiments illustrate its convergence. Not only is this method applicable for triangular mesh, but also can be naturally extended to arbitrary polygonal surface mesh. Quality improvements of demonstrations on triangular and quadrilateral meshes show the effectiveness of this method.

Long term comparative evaluation of two types of absorbable meshes in partial abdominal wall defects: an experimental study in rabbits.

PURPOSE: Synthetic prosthetic materials that are fully absorbable seek to reduce the host foreign body reaction and promote host tissue regeneration. This preclinical trial was designed to analyse, in the long term, the behaviour of two prosthetic meshes, one synthetic and one composed of porcine collagen, in abdominal wall reconstruction. METHODS: Partial defects were created in the abdominal walls of New Zealand rabbits and repaired using a synthetic absorbable mesh (Phasix™) or a non-crosslinked collagen bioprosthesis (Protexa™). After 3, 6, 12 and 18 months, specimens were recovered for light microscopy and collagen expression analysis to examine new host tissue incorporation, macrophage response and biomechanical strength. RESULTS: Both materials showed good host tissue incorporation in line with their spatial structure. At 18 months postimplant, Protexa™ was highly reabsorbed while the biodegradation of Phasix™ was still incomplete. Collagenization of both materials was good. Macrophage counts steadily decreased over time in response to Phasix™, yet persisted in the collagen meshes. At 18 months, zones of loose tissue were observed at the implant site in the absence of herniation in both implant types. The stress-stretch behaviour of Phasix™ implants decreased over time, being more pronounced during the period of 12-18 months. Nevertheless, the abdominal wall repaired with Protexa™ became stiffer over time. CONCLUSION: Eighteen months after the implant both materials showed good compatibility but the biodegradation of Phasix™ and Protexa™ was incomplete. No signs of hernia were observed at 18 months with the stress-stretch relations being similar for both implants, regardless of the more compliant abdominal wall repaired with Protexa™ at short term.