Objective Mesh infection may occur after incisional hernia repair using prosthetic mesh. Preparation of antibiotics-bonded meshes to prevent infection is one of the solutions. To evaluate the anti-infection effect of polypropylene mesh bonded norvancomycin slow-release microsphere by preparing the rat model of incisional hernia repair contaminatedwith Staphylococcus aureus. Methods The norvancomycin slow-release microspheres were prepared by emulsion and solvent evaporation method and they were bonded to polypropylene mesh (50 mg/mesh). The appearance of the microspheres was observed using scanning electronic microscope (SEM). The content of norvancomycin in microspheres and the release rate of the norvancomycin in norvancomycin-bonded polypropylene mesh were detected using high performance l iquid chromatography method. The rat models of incisional hernia were developed in 40 healthy Sprague Dawley rats, aged 10-11 weeks and weighing 200-250 g. The rats were divided randomly into the experimental group (norvancomycin-bonded polypropylene mesh repair, n=20) and the control group (polypropylene mesh repair, n=20). And then the mesh was contaminated with Staphylococcus aureus. The wound heal ing was observed after operation. At 3 weeks after operation, the mesh and the tissue around the mesh were harvested to perform histological observation and to classify the inflammatory reaction degree. Results The norvancomycin microsphere had integrated appearance and smooth surface with uniform particle diameter, 64% of particlediameter at 60 to 100 μm, and the loading-capacity of norvancomycin was 19.79%. The norvancomycin-bonded polypropylene patch had well-distributed surface and the loading-capacity of norvancomycin was (7.90 ± 0.85) mg/cm2. The release time of norvancomycin in vitro could last above 28 days and the accumulative release rate was 72.6%. The rats of 2 groups all survived to experiment completion. Wound infection occurred in 2 rats of the experimental group (10%) and 20 rats of the control group (100%), showing significant difference (χ2=32.727 3, P=0.000 0). The inflammatory reaction in experimental group was not obvious, grade I in 16 rats and grade II in 4 rats, and numerous inflammatory cell infiltration occurred in the control group, grade II in 3 rats and grade III in 17 rats, showing significant difference (Z=32.314, P=0.000). Conclusion The polypropylene mesh bonded norvancomycin slow-release microsphere has definite anti-infection effect in rat model of incisional hernia repair contaminated by Staphylococcus aureus.
Objective To evaluate the outcome of pedicle graft of greater omentum and polypropylene mesh in reconstruction of large defect of abdominal wall caused by surgical incision. Methods From 1994 to 2004, 12 cases of large abdominal wall defects were repaired with pedicle graft of greater omentum and polypropylene mesh after removal of abdominal wall tumor; the defect sizes of abdominal wall ranged from 10 cm×7 cm to 25 cm×17 cm. Results The abdominal wall wound in 12 cases were healed by first intention. After a follow-up of 1 to 5 years, no complications of abdominal hernia, infection and intestine obstruction occurred in all patients. Conclusion It is reliable to repair abdominal wall defect caused by surgical incision with pedicle graft of greater omentum and polypropylene mesh instead of peritoneum.
Objective To compare the effect of small intestinal submucosa(SIS)and polypropylene mesh(PPM) on repairing abdominal wall defects in rats, and toprobe into the feasibility of using SIS to repair the abdominal wall defects. Methods 100 SD rats(50 males and 50 females)were randomly divided into 2 groups(n=50). Their weight ranged from 200 to 250 g.Full thickness abdominal wall defects (2 cm×2 cm) were created by surgery and were repaired with SIS and PPM respectively. At different postoperative time (1st, 2nd, 4th, 8th and 12th week), animals were sacrificed to make histological observation. The tensile strengthand the development of adhesions were measured and observed. Results 95 animals survived and were healthy after surgery. No inflammatory response and obvious immunoreaction were observed in both groups. One week after operation, the tensile strengthof abdominal wall in SIS group (204.30±5.13 mmHg) was lower than that in PPMgroup(240.0±10.0 mmHg) at 1st week(P＜0.05),and there were no difference at 4th, 8th, 12th week. Adhesions were more marked in PPM group thanthat in SIS group(P＜0.05). Conclusion Both SIS and PPM are histologically compatible when used in rats and can maintain sufficient tensile strength. SIS is superior to PPM in regards to tissue compatibility and adhesion formation.
Objective To prepare a new sirolimus drug-coated polypropylene (SRL-PP) mesh by grafting he sirolimus onto the surface of the polypropylene (PP) mesh via chemical reaction, and to apply the new mesh to animal experiment to explore its anti-adhesion properties.MethodsThe sirolimus was grafted onto the surface of the mesh by chemical reaction to prepare the SRL-PP mesh, which was compared with the PP mesh and the polyethylene glycol modified polypropylene (PEG-PP) mesh. The three groups of meshes were respectively characterized (infrared spectroscopy test, contact angle measurement), and their tensile property was measured. These meshes were implanted into the abdominal cavity of the rats respectively. The anti-adhesion properties of the new sirolimus drug-coated mesh was studied by intraperitoneal adhesion and histopathological change in rats.ResultsThe results of infrared spectrum analysis showed that there was a new absorption peak at the wavelength 1 643 cm–1 (amide group) of SRL-PP mesh, suggesting that sirolimus drug was successfully uploaded onto the surface of the mesh; the SRL-PP mesh was excellent in hydrophilicity, which provided a favorable condition for the growth of peritoneal mesothelial cells. There was no significant difference in mechanical properties between SRL-PP mesh and PP mesh or PEG-PP mesh, which provided a good mechanical guarantee for clinical application. The degree of abdominal adhesion in SRL-PP mesh group (1.00±0.58) was significantly lower than that in PP mesh group (5.17±0.69) and PEG-PP mesh group (4.00±0.58), and the tD value between SRL-PP mesh group and PP mesh group was 2.76 (P<0.05). The number of inflammatory cells and the expression of inflammatory cytokines in the adhesion tissue in SRL-PP mesh group were significantly lower than those in PP mesh group and PEG-PP mesh group.ConclusionsThe sirolimus is successfully loaded onto the surface in the PP mesh by chemical reaction. Animal experiment shows that the sirolimus drug-coated mesh can significantly reduce the abdominal adhesion of the rats, which provides a basis for clinical trial and application.