A new testis prosthesis material: polymethylmethacrylate.

Introduction: Silicone has been the standard prosthesis material for the last three decades but new materials are being searched because of the known disadvantages of silicone such as migration and high cost. We wanted to test in rats whether or not polymethylmethacrylate could be an alternative to silicone.

Materials And Methods: We prepared polymethylmethacrylate and silicone testis prostheses which were similar to testis size of rats. Eleven rats were implanted with polymethylmethacrylate, 11 others were implanted with a silicone prosthesis and sham operation was performed in 10 rats. Three months later the scrotums of the animals were removed with the prosthesis for a quantitative analysis of the chronic inflammation and fibrotic reaction and to measure the thickness of the capsule.

Result: Rejection and infection were not observed in any of the prosthesis-implanted rats. Both prosthesis groups displayed increased vascularization, hemosiderin accumulation and fibrotic and hyalinized tissue formation that replaced the muscle. Chronic inflammation was measured and found to be higher in the polymethylmethacrylate group and the difference was not found to be significant. The average thicknesses of the capsules around the polymethylmethacrylate and silicone groups were found to be 58.4 and 46.8 microm, respectively, and that difference was not significant again.

Conclusions: In the short term polymethylmethacrylate was equally well tolerated, but the low cost of polymethylmethacrylate made it more advantageous.