Evaluation of self-reinforced polyglycolide membrane implanted in the subcutis of rabbits

Background: Self-reinforced absorbable implants have been developed recentl y to use in hard tissue reconstructive surgery. Polyglycolide is a biocompa tible polymer from which the suture Dexon is made and widely used. Aims: To study histologically the behaviour of self-reinforced polyglycolid e membrane (SR-PGA) in rabbits' ears. Material and Methods: SR-PGA membranes, 0.4 mm thick, were implanted in the subcutis of the ears of 24 New Zealand white rabbits. Sham operations were carried out on the contralateral ear of each rabbit. The rabbits were foll owed-up for 4, 12 and 20 weeks. Attention was directed towards external mac roscopic changes in the rabbits' ears. After sacrifice, the ears were taken as specimens, inspected for any evidence of infection, sinus formation or fluid accumulation and histological examination was carried out. Results: No complications such as infection, fluid accumulation or sinus fo rmation were observed. Histologically, the membranes induced a foreign-body reaction involving fibrous tissue encapsulation, macrophages and giant cel ls. Fibrous tissue and inflammatory cells were seen between the PGA fibres. The membranes underwent progressive degradation throughout the follow-up p eriod. However, PGA material could be still seen 20 weeks postoperatively, with a small amount of fibrous tissue and macrophages and giant cells. The implant-cartilage interface comprised fibrous and fatty tissue. Conclusions: SR-PGA membranes are biocompatible when implanted in the subcu tis of the ears of rabbits.