The Study Of Repairing Materials In Abdominal Wall Defect On Rats Under Contaminated Environment

Objective To observe the anti-adhesion and repair effect of3composite patcheswhich composed of polylactide-co-caprolactone(PLC), hyaluronic acid(HA),collagen,and polypropylene(PP) mesh repairing abdominal wall defect in rats undercontaminated environment, and to investigate the characteristics of3composite patchesand the feasibility of one-stage repair， and to compare with acellular dermalmatrix(ADM) patch.Methods One hundred and twenty-four adult male Wistar rats(weighting150-250g)were randomly divided into4groups(n=31): ADM patches(group A),PP/PLCcomposite patches(group B), PP/HA/PLC composite patches(group C), andPP/collagen/PLC composite patches(group D). One rat was selected from each group toprepare the contaminated homogenate of the small intestine. The abdominal wall defectmodels(1cm in diameter)were established in other rats, and the defects were repairedwith4patches(1.5cm in diameter)according to grouping method. At30,60, and90dayspostoperatively, the adhesion was observed, and the patch and adjacent tissue washarvested for histological observation.Result Seven rats died at10-70days postoperatively(1in group A,2in group B,3ingroup C, and1in group D). No wound infection, intestinal obstruction, or herniaoccurred in4groups. Adhesion was observed between abdominal viscera and the patch,especially intestine, epiploon, and liver. According to the modified KA TADA criteria,no significant difference in the adhesion score was found among3groups at30and60days(p＞0.05)； the adhesion score was significantly lower in group D than in group Band C at90days(P＜0.05),and no significant difference in the group D and A. Thehistological results showed that inflammatory call infiltration, fibroblasts, secretedcollagen, and the residual absorbable material were observed around the patch at30 days in B、C、D groups. Decreased inflammatory cell infiltration, increase fibroblastsand residual PLC were observed at60days in B、C、D groups. At90days, thefibroblasts became increasingly mature, collagen deposited, the mesothelium formedgradually, and the residual PLC decreased.Conclusion In contaminated environment, PP/collagen/PLC composite patch issuperior to PP/PLC and PP/HA/PLC，and is similar with ADM patch, compositepatches in aspect of abdominal adhesion and inflammatory reaction, and it is moreapplicable to one-stage repair of rat abdominal wall defect. But it is necessary to furtherstudy in the long-term efficacy and the security of the composite patch.