Biodegradability and Safety Study of LifeMesh™, a Novel Self-adhesive Mesh, in Sprague-Dawley Rats.

Self-adhesive meshes are being developed to avoid complications due to traumatic fixation methods. LifeMesh™ is a novel self-adhesive mesh with a biodegradable gelatin adhesive layer developed for hernia repair. The aim of this study was to assess the safety and biodegradability of LifeMesh in Sprague-Dawley (SD) rats for 6 weeks, in comparison to a bare polypropylene (BPP) mesh fixed with sutures. LifeMesh was tolerated well and its implantation did not result in any adverse local reaction, and its adhesive layer was substantially degraded after 4 weeks. Histopathological examination revealed that the presence of the adhesive contributed to a uniform thickness of the granulation tissue surrounding the mesh, in contrast to a nonuniform granulation tissue with BPP. Nonuniform granulation tissue suggests that there will be poorer integration of the mesh to the abdominal wall. The use of LifeMesh also resulted in less adhesions of internal organs with a smaller surface area of involvement. These findings lend support to the potential benefit of LifeMesh for hernia repair in humans and expand the available information on the typical histopathological findings expected with biodegradable implants in the peritoneal cavity of SD rats.

An Immunopathological Evaluation of the Porcine Cholecyst Matrix as a Muscle Repair Graft in a Male Rat Abdominal Wall Defect Model.

With the increasing use of animal-based biomaterials for regenerative medical applications, the need for their safety assessment is paramount. A porcine cholecyst-derived scaffold (CDS), intended as a muscle repair graft, prepared by a nondetergent/enzymatic method was engrafted in a rat abdominal wall defect model. Host tissue-scaffold interface samples were collected 2, 8, and 16 weeks postimplantation and evaluated by histopathology, immunohistochemistry, and electron microscopy. The nature of the tissue reaction was compared with those induced by a jejunum-derived scaffold (JDS) prepared by the same method and a commercial-grade small intestinal submucosa (CSIS) scaffold. A study of the immunopathological response in major lymphoid tissues and immunophenotyping for M1 and M2 macrophages was performed at the host tissue-scaffold interface. Further, "irritancy scores" for CDS and JDS were determined using CSIS as the reference material. Both CDS and JDS appeared to be potential biomaterials for muscle grafts, but the former stimulated a skeletal muscle tissue remodeling response predominated by M2 macrophages. The data support the notion that biomaterials with similar biocompatibility, based on local tissue response on implantation, may cause differential immunogenicity. Additionally, CDS compared to JDS and CSIS was found to be less immunotoxic.

Early morphological changes in tissues when replacing abdominal wall defects by bacterial nanocellulose in experimental trials.

Experimental trials were done on five dogs to explore if an anterior abdominal wall defect could be repaired using wet (99.9%), compact BNC membranes produced by the Мedusomyces gisevii Sa-12 symbiotic culture. The abdominal wall defect was simulated by middle-midline laparotomy, and a BNC membrane was then fixed to open aponeurotic edges with blanket suture (Prolene 4-0, Ethicon). A comparative study was also done to reinforce the aponeurotic defect with both the BNC membrane and polypropylene mesh (PPM) (Ultrapro, Ethicon). The materials were harvested at 14 and 60 days postoperative to visually evaluate their location in the abdominal tissues and evaluate the presence of BNC and PPM adhesions to the intestinal loops, followed by histologic examination of the tissue response to these prosthetics. The BNC exhibited good fixation to the anterior abdominal wall to form on the 14th day a capsule of loose fibrin around the BNC. Active reparative processes were observed at the BNC site at 60 days post-surgery to generate new, stable connective-tissue elements (macrophages, giant cells, fibroblasts, fibrin) and neocapillaries. Negligible intraperitoneal adhesions were detected between the BNC and the intestinal loops as compared to the case of PPM. There were no suppurative complications throughout the postsurgical period. We noticed on the 60th day after the BNC placement that collagenous elements and new capillary vessels were actively formed in the abdominal wall tissues, generating a dense postoperative cicatrix whose intraperitoneal adhesions to the intestinal loops were insignificant compared to the PPM graft.

Pro - inflammatory cytokines and metalloproteinase activation in polypropylene mesh implant in rat subcutaneous tissue.

AIMS AND OBJECTIVES: Polypropylene meshes have been increasingly adopted for correction of pelvic organ prolapse due to its lower recurrence rate when compared to surgeries without meshes. The study of the interaction of these materials with the host tissue may contribute to the development of materials with best biocompatibility and, consequently, less complication rates. MATERIALS AND METHODS: The present study compares the inflammatory reaction of standard-weight (SW) and lightweight (LW) meshes (72 g/m216g/m2 respectively), implanted in the abdomen of 20 adult rats, which were euthanized in four or 30 days. Quantification of pro-inflammatory markers, IL-1 and TNF-α, and of metalloproteinases, MMP2 and MMP3, were carried out through immunohistochemistry with AxioVision ® software. RESULTS: There were no significant differences in the quantification of IL-1 and TNF-α in LW versus SW meshes. However, IL-1 quantification increased along time (30 days >4 days, p=0.0269). Also, MMP-2 quantification was similar to SW and LW and both presented a significant increase along time (30 days >4 days, p < 0.0001). MMP-3 quantification also showed no difference between the SW and LW groups, but increased along time (30 days >4 days, p=0.02). CONCLUSIONS: Mesh's density did not influence the quantification of pro-inflammatory cytokines IL-1 and TNF-α and metalloproteinases 2 and 3. The increased expression of IL-1, MMP-2 and MMP-3 over time could represent a longstanding inflammatory response after PP mesh implantation. Possibly, the occurrence of adverse events following PP prosthetic implants can be influenced by other factors, not solely related to the amount of implanted material.

Strength and histology of a nanofiber scaffold in rats.

BACKGROUND: Full-thickness soft tissue defects from congenital absence or traumatic loss are difficult to surgically manage. Healing requires cell migration, organization of an extracellular matrix, inflammation, and wound coverage. PLCL (70:30 lactide:caprolactone, Purac), poly(propylene glycol) nanofibrous scaffolds enhance cell infiltration in vitro. This study compares strength and tissue ingrowth of aligned and unaligned nanofibrous scaffolds to absorbable and permanent meshes. We hypothesize that PLCL nanofibrous grafts will provide strength necessary for physiological function while serving as a scaffold to guide native tissue regeneration in vivo. MATERIALS AND METHODS: Abdominal wall defects were created in 126 rats followed by underlay implantation of Vicryl, Gore-Tex, aligned, or unaligned PLCL Nanofiber mesh. Specimens were harvested at 2, 6, and 12 wk for strength testing and 2, 12, and 24 wk for histopathologic evaluation. Specimens were graded for cellular infiltration, multinucleated giant cells (MNG), vascularity, and tissue organization. Mean scores were compared and analyzed with non-parametric testing. RESULTS: The PLCL grafts maintained structural integrity until at least 12 wk and exhibited substantial tissue replacement at 24 wk. At 12 wk, only the aligned PLCL had persistent cellular infiltration of the graft, whereas both aligned and unaligned PLCL grafts showed the presence of MNG. The presence of MNGs decreased in the aligned PLCL graft by 24 wk. CONCLUSIONS: The aligned PLCL nanofiber mesh offers early strength comparable to Gore-Tex but breaks down and is replaced with cellular ingrowth creating a favorable option in management of complex surgical wounds or native soft tissue defects.

Endometriosis-associated clear cell carcinoma arising in caesarean section scar: a case report and review of the literature.

BACKGROUND: Malignant transformation has been reported in approximately 1% of the endometriosis cases; herein, we report a case of clear cell endometrial carcinoma arising from endometriosis foci located within a caesarean section scar. CASE PRESENTATION: In November 2014, a Caucasian, 44-year-old woman was transferred to our institution because of severe respiratory failure due to massive lung embolism and rapid enlargement of a subcutaneous suprapubic mass. Abdomino-pelvic magnetic resonance showed a 10.5 × 5.0 × 5.0 cm subcutaneous solid mass involving the rectus abdominis muscle. Pelvic organs appeared normal, while right external iliac lymph nodes appeared enlarged (maximum diameter = 16 mm). A whole-body positron emission tomography/computed tomography scan showed irregular uptake of the radiotracer in the 22 cm mass of the abdominal wall, and in enlarged external iliac and inguinal lymph nodes. In December 2014, the patient underwent exploratory laparoscopy showing normal adnexae and pelvic organs; peritoneal as well as cervical, endometrial and vesical biopsies were negative. The patient was administered neo-adjuvant chemotherapy with carboplatin and paclitaxel, weekly, without benefit and then underwent wide resection of the abdominal mass, partial removal of rectus abdominis muscle and fascia, radical hysterectomy, bilateral salpingo-oophorectomy, and inguinal and pelvic lymphadenectomy. The muscular gap was repaired employing a gore-tex mesh while the external covering was made by a pedicled perforator fasciocutaneous anterolateral thigh flap. Final diagnosis was clear cell endometrial adenocarcinoma arising from endometriosis foci within the caesarean section scar. Pelvic and inguinal lymph nodes were metastatic. Tumor cells were positive for CK7 EMA, CKAE1/AE3, CD15, CA-125, while immunoreaction for Calretinin, WT1, estrogen, and progesterone receptors, cytokeratin 20, CD10, alpha fetoprotein, CDX2, TTF1, and thyroglobulin were all negative. Liver relapse occurred after 2 months; despite 3 cycles of pegylated liposomal doxorubicin (20 mg/m2, biweekly administration), the death of the patient disease occurred 1 month later. CONCLUSIONS: Attention should be focused on careful evaluation of patient history in terms of pelvic surgery, and symptoms suggestive of endometriosis such as repeated occurrence of endometriosis nodules at CS scar, or cyclic pain, or volume changes of the nodules.

[Morphological and functional aspects of recurrent postoperative ventral hernias]. / Morfofunktsional'nye aspekty retsidiva posleoperatsionnykh ventral'nykh gryzh.

AIM: To define the optimal treatment of postoperative ventral hernias. MATERIAL AND METHODS: It was performed microscopic examination of intraoperative specimens which were obtained from 40 patients with medium, large and giant hernia. The aim was to reveal ultrastructural changes and morphological features which are associated with abdominal wall weakness in case of postoperative ventral hernia. There were 28 (70%) cases of primary postoperative hernia and 12 (30%) cases of recurrent and multiple-recurrent hernia. In 4 patients polypropylene mesh implants were implanted prior to recurrence. Tissue specimens were obtained from the top of herniation, hernial ring and in 6 cm from the hernial ring. RESULTS AND DISCUSSION: Electron microscopy showed that postoperative ventral hernias are accompanied by ultrastructural destructive changes in cells of the skin, aponeurosis and muscles that indicates on morphofunctional failure of abdominal wall tissues. Swelling and degradation of collagen, fibroblasts vacuolization, capillary sludge of erythrocytes, development of vacuum zones with the fragments of altered collagen fibrils, red blood cells and mast cells are morphological signs of micronecrosis followed by abdominal wall weakness and postoperative ventral hernias. CONCLUSION: Postoperative ventral hernias are associated with morphological and functional failure of abdominal wall due to tissue destructive changes. Therefore, this obviously defective tissue can not be used per se and especially with tension. Mesh implants should be applied.

[[Substantiation of choisce of the kind, localization and method of the implant fixing in alloplasty of the abdominal wall complex defects].]

The method of the implant fixation for prophylaxis of complications after alloplasty of complex abdominal wall defects was proposed. Taking into account physico-mechan- ical parameters of implant, degree of anisotropy, in accordance to mechanical and morphological characteristics of the abdominal wall musculo-aponeurotic structures, it is possible to individualize the choice maximally, to plan the alloplasty kind, and to determine the method of optimal surgical treatment objectively.

Remodeling characteristics and collagen distribution in biological scaffold materials explanted from human subjects after abdominal soft tissue reconstruction: an analysis of scaffold remodeling characteristics by patient risk factors and surgical site classifications.

OBJECTIVE: The study purpose was to evaluate the associations between patient characteristics or surgical site classifications and the histologic remodeling scores of biologic meshes biopsied from abdominal soft tissue repair sites in the first attempt to generate a multivariable risk-prediction model of nonconstructive remodeling. BACKGROUND: Host characteristics and surgical site assessments may predict remodeling degree for biologic meshes used to reinforce abdominal tissue repair sites. METHODS: Biologic meshes were biopsied from the abdominal tissue repair sites of n = 40 patients during an abdominal reexploration, stained with hematoxylin and eosin, and evaluated according to a semi-quantitative scoring system for remodeling characteristics (cell types, cell infiltration, extracellular matrix deposition, scaffold degradation, fibrous encapsulation, and neovascularization) and a mean composite score. Biopsies were stained with Sirius Red and Fast Green and analyzed to determine the collagen I:III ratio. On the basis of univariate analyses between subject clinical characteristics or surgical site classification and the histologic remodeling scores, cohort variables were selected for multivariable regression models using P ≤ 0.200. RESULTS: The model selection process for cell infiltration score yielded 2 variables: age at mesh implantation and mesh classification (C statistic = 0.989). For the mean composite score, the model selection process yielded 2 variables: age at mesh implantation and mesh classification (r = 0.449). CONCLUSIONS: These preliminary results constitute the first steps in generating a risk-prediction model that predicts the patients and clinical circumstances most likely to experience nonconstructive remodeling of abdominal tissue repair sites with biologic mesh reinforcement.

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.

Comparing the host tissue response and peritoneal behavior of composite meshes used for ventral hernia repair.

BACKGROUND: The use of a prosthetic material is the best treatment option for ventral hernia repair; one of the most frequently performed abdominal surgery procedures. This preclinical study compares the behavior of a new mesh (Parietex composite ventral patch [Ptx]) with that of two existing meshes used for ventral hernia repair. MATERIALS AND METHODS: Fifty-four New Zealand White rabbits (3000 g) were used in an experimental model of umbilical hernia repair (diameter 1.5 cm). The materials tested were: Ventralex ST hernia patch (Vent) (Bard Davol Inc, Warwick, RI) (n = 18); Proceed ventral patch (Ethicon, Somerville, NJ) (PVP) (n = 18) and Ptx (Covidien, Sofradim, Trevoux, France) (n = 18). At 3, 7, 14 d, and 6 wk after implant, peritoneal behavior and adhesion formation were assessed by sequential laparoscopy. Mesh mesothelial cover was determined by scanning electron microscopy. Host tissue ingrowth (collagens I and III) and the macrophage response were assessed by immunohistochemical labeling. Animals were euthanized at 2, 6 wk, and 6 mo after surgery. Data were compared using the Mann-Whitney U test. RESULTS: Adhesion formation from 3 d-6 wk was significantly greater (P < 0.05) for PVP compared with Vent or Ptx. Three encapsulated PVP implants showed "tissue-integrated" adhesions affecting the intestinal loops. All three implant types showed similar patterns of collagen l and III deposition. The PVP mesh elicited the greater macrophage response both at 2 wk and 6 mo. CONCLUSIONS: Ptx and Vent showed excellent mesothelialization, which led to minimum adhesion formation. The appropriate tissue integration of Ptx in the parietal neoperitoneum is likely attributable to its deployment system.

[Application of C-QUR V-Patch system while performing preperitoneal alloplasty for small and middle umbilical hernias].

Own experience of application of a system C-QUR V-Patch, manufactured by "Atrium" (Maquet Getinge Group) firm while performing preperitoneal alloherniolasty for small and middle umbilical hernias, was summarized. In this implant polypropylene mesh, covered by layer of preparation of omega-3 class of polyunsaturated fatty acids, capable of bioabsorption, joined with a newest technologies of a space memory. Its application guarantees lesser traumaticity and duration of operation, absence of peritoneal damage, small sizes of operation wound, what permits to accelerate significantly the patients' working ability restoration, as well as to achieve a quality of their life improvement.

Reconstruction of large-size abdominal wall defect using biodegradable poly-p-dioxanone mesh: an experimental canine study.

BACKGROUND: Reconstruction of large-size abdominal wall defect (AWDs) is a huge challenge faced in current surgical practice. In this study, we aimed to evaluate the effectiveness and safety of biodegradable poly-p-dioxanone (PDO) mesh for reconstructing large-size AWDs in an experimental canine model. METHODS: Eighteen experimental canines were randomly and equally divided into three groups, namely, a PDO group, a Marlex group and a control group (n = 6 each). Following the creation of a 6 cm × 5.5 cm AWD, PDO mesh and Marlex mesh were used to reconstruct the defect in the PDO and Marlex groups, respectively. The defect was closed using relaxation sutures alone in the control group. Animals were killed 24 weeks after surgery, and reconstruction outcomes were evaluated using radiography, histology and biomechanical testing. RESULTS: All animals except those in the control group survived the experiment. The PDO group showed no wound dehiscence, herniation or infection, whereas the animals in the Marlex group exhibited marked foreign body reactions. The PDO group had less intraabdominal adhesion than the Marlex group. As shown by radiography, histology and biomechanical testing, PDO mesh exhibited complete degradation and favorable biochemical strength at 24 weeks postsurgery. CONCLUSIONS: PDO mesh implantation is an effective, safe treatment modality for reconstructing large-size AWDs.

Multiple visceral resection after locoregional recurrence of signet ring cell gastric cancer -- case report and literature review.

Recurrence is the most important cause of treatment failure in patients with advanced gastric cancer, even after curative surgery. Surgery plays an important role in these patients,even in cases of multivisceral involvement. In selected cases good biological resources - surgery is the only viable choice to prolong survival. This report describes the case of a 41 year-old patient presenting a locoregional recurrence with multiple visceral involvement at 15 months after radical subtotal gastrectomy with D2 lymph node dissection for antral gastric cancer.

Evaluation of Interaction With Bio-absorbable Polyglycolic Acid Spacer and Anti-adhesive Agents Using a Rat Experimental Model.

BACKGROUND/AIM: Neskeep®, an absorbable polyglycolic acid spacer, has been developed as the optimal material for spacer placement surgery. However, preventing its severe adhesion is a crucial concern. Therefore, we aimed to identify an effective anti-adhesion agent for Neskeep® using rat models. MATERIALS AND METHODS: Animal experiments were performed using 60 rats, which underwent Neskeep® placement on the abdominal wall. Three types of anti-adhesion agents were employed, establishing four subgroups: Seprafilm®, INTERCEED®, AdSpray®, and only Neskeep® (control) groups. Rats were sacrificed on postoperative days 7, 14, and 28 to assess adhesion levels around the Neskeep® Macroscopic visual assessment with the Lauder score and histopathological evaluation were performed to assess the degree of adhesion. RESULTS: There were no significant differences in the proportion of Lauder scores on days 7 and 14 between the four groups. Histological evaluation revealed no significant differences between groups at any observation time. However, the mean Lauder scores at day 28 were 5.0, 1.6, 4.0, and 4.8 in the Neskeep®, Seprafilm®, INTERCEED®, and AdSpray® groups, respectively. The proportion of milder Lauder score was significantly higher in the Seprafilm® group on day 28. CONCLUSION: Seprafilm® may exhibit an anti-adhesive effect when used with Neskeep®.

Fabrication of a modified bacterial cellulose with different alkyl chains and its prevention of abdominal adhesion.

Abdominal hernia mesh is a common product which is used for prevention of abdominal adhesion and repairing abdominal wall defect. Currently, designing and preparing a novel bio-mesh material with prevention of adhesion, promoting repair and good biocompatibility simultaneously remain a great bottleneck. In this study, a novel siloxane-modified bacterial cellulose (BC) was designed and fabricated by chemical vapor deposition silylation, then the effects of different alkyl chains length of siloxane on surface properties and cell behaviors were explored. The effect of preventing of abdominal adhesion and repairing abdominal wall defect in rats with the siloxane-modified BC was evaluated. As the grafted alkyl chains become longer, the surface of the siloxane-modified BC can be transformed from super hydrophilic to hydrophobic. In vivo results showed that BC-C16 had good long-term anti-adhesion effect, good tissue adaptability and histocompatibility, which is expected to be used as a new anti-adhesion hernia repair material in clinic.

Durable and Robust Antibacterial Polypropylene Hernia Mesh for Abdominal Wall Defect Repair.

Polypropylene (PP) mesh is commonly used in repairing abdominal wall hernia (AWH). However, the use of synthetic prosthesis comes with the risk of developing a prosthetic infection, resulting in delayed healing, secondary surgery, and potentially increased mortality. To address these issues, a facile surface functionalization strategy for PP mesh based on phytic acid (PA) and polyhexamethylene guanidine (PHMG) was constructed through a one-step co-deposition process, referred to as the PA/PHMG coating. The development of PA/PHMG coating is mainly attributed to the surface affinity of PA and the electrostatic interactions between PA and PHMG. The PA/PHMG coating could be completed within 4 h under mild conditions. The prepared PA/PHMG coatings on PP mesh surfaces exhibited desirable biocompatibility toward mammalian cells and excellent antibacterial properties against the notorious "superbug" methicillin-resistant Staphylococcus aureus (MRSA) and tetracycline-resistant Escherichia coli (TRE). The PA/PHMG-coated PP meshes showed killing ratios of over 99% against MRSA in an infected abdominal wall hernia repair model. Furthermore, histological and immunohistochemical analysis revealed a significantly attenuated degree of neutrophil infiltration in the PA/PHMG coating group, attributed to the decreased bacterial numbers alleviating the inflammatory response at the implant sites. Meanwhile, the pristine PP and PA/PHMG-coated meshes showed effective tissue repair, with the PA/PHMG coating group exhibiting enhanced angiogenesis compared with pristine PP meshes, suggesting superior tissue restoration. Additionally, PP meshes with the highest PHMG weight ratio (PA/PHMG(3)) exhibited excellent long-term robustness under phosphate-buffered saline (PBS) immersion with a killing ratio against MRSA still exceeding 95% after 60 days of PBS immersion. The present work provides a facile and promising approach for developing antibacterial implants.

One-year outcome of biological and synthetic bioabsorbable meshes for augmentation of large abdominal wall defects in a rabbit model.

BACKGROUND: Long-term efficacy of biological and synthetic bioabsorbable meshes for large hernia repair is currently unclear. This rabbit study is aimed at investigating 1-y outcome of biological and synthetic bioabsorbable meshes for augmentation of large abdominal wall defects. MATERIALS AND METHODS: In 46 rabbits, an 11 × 4 cm, full-thickness abdominal wall defect was repaired primarily, or with cross-linked (Permacol, Collamend) or non-cross-linked (Surgisis 4-ply, Surgisis Biodesign) biological, synthetic bioabsorbable (GORE BIO-A Tissue Reinforcement [TR], TIGR Matrix Surgical Mesh [MSM]), or polypropylene (Bard Mesh) meshes, using the underlay augmentation technique. One year after surgery, primary outcome was recurrence; secondary outcomes were tensile strength, histologic degree of tissue remodeling, and intraabdominal adhesion formation. RESULTS: Only two Surgisis 4-ply animals (50%) presented with a recurrent hernia. All GORE BIO-A TR meshes were completely resorbed and, as after primary repair, well-organized connective tissue without inflammation was present, with moderate adhesion formation and sufficient tensile strength. Cross-linked biological and TIGR MSM meshes demonstrated highest tensile strength but were only partially incorporated, with similar foreign body reaction and adhesion formation as polypropylene meshes in the TIGR MSM group, and minimal degradation and moderate adhesion formation in the cross-linked biological group. In the non-cross-linked biological group sufficient tensile strength and moderate adhesion formation were found, with pronounced inflammation if mesh remnants were present. CONCLUSIONS: Synthetic bioabsorbable GORE BIO-A TR meshes were associated with optimal tissue remodeling, with complete resorption, presence of well-organized tissue, and no inflammation. However, mesh augmentation had no advantages regarding recurrence rate versus primary repair of large abdominal wall defects.

Biologic meshes are not superior to synthetic meshes in ventral hernia repair: an experimental study with long-term follow-up evaluation.

BACKGROUND: In laparoscopic incisional hernia repair, direct contact between the prosthesis and the abdominal viscera is inevitable, which may lead to an inflammatory reaction resulting in abdominal adhesion formation. This study compared five different synthetic and biologic meshes in terms of adhesion formation, shrinkage, incorporation, and histologic characteristics after a period of 30 and 90 days. METHODS: In 85 rats, a mesh was positioned intraperitoneally in direct contact with the viscera. Five different meshes were implanted: Prolene (polypropylene), Parietex composite (collagen-coated polyester), Strattice (porcine dermis, non-cross-linked), Surgisis (porcine small intestine submucosa, non-cross-linked), and Permacol (porcine dermis, cross-linked). The meshes were tested in terms of adhesion formation, shrinkage, and incorporation after a period of 30 and 90 days. Additionally, collagen formation after 90 days was determined. RESULTS: Significantly less adhesion formation was observed with Parietex composite (5 %; interquartile range [IQR], 2-5 %) and Strattice (5 %; IQR, 4-10 %) in the long term. In contrast, organs were attached to Permacol with four of seven meshes (57 %), and adhesion coverage of Surgisis mesh was present in 66 % (IQR, 0-100 %) of the cases. After 90 days, the best incorporation was seen with the Parietex composite mesh (79 %; IQR, 61-83 %). After 90 days, major alterations in adhesion formation were seen compared with 30 days. Histologically, Strattice and Parietex composite showed a new mesothelial layer on the visceral side of the mesh. Microscopic degradation and new collagen formation were seen in the Surgisis group. CONCLUSIONS: Parietex composite mesh demonstrated the best long-term results compared with all the other meshes. The biologic non-cross-linked mesh, Strattice, showed little adhesion formation and moderate shrinkage but poor incorporation. Biologic meshes are promising, but varying results require a more detailed investigation and demonstrate that biologic meshes are not necessarily superior to synthetic meshes. The significant changes that take place between 30 and 90 days should lead to careful interpretation of short-term experimental results.

Plastic efficiency of different implants used for repair of soft and bone tissue defects.

The results of clinical and experimental morphological studies of regenerates forming after replacement of large defects of the abdominal wall and tibia with implants from different materials (polytetrafluoroethylene, reperene, prolene, titanium, and titanium nickelide) are analyzed. Study of the regenerate histology and fibroarchitectonics has shown good prospects of mesh constructions from titanium nickelide for effective surgical repair of these defects. The use of this implant seems to be theoretically well-based and promising, particularly under conditions of suppurative infection and low individual reparative regenerative potential.