Kaneshiro Y, Takamatsu K, Koshimune M, Nakatsuka H, and Imai Y. Orthop. Surg, Osaka City University, 1-4-3, Asahimachi, Abeno-ku, Osaka, Japan
Many investigators have reported how to repair peripheral nerve gap in experimental study with using some nerve conduit. Recently various bioabsorbable polymer tubes have been reported. However those results were not satisfied enough for clinical use. The purpose of this study is to introduce our new bioabsorbable polymer tube and to report its stiffness, flexibility and absorption in vivo including cases in long follow up. Our new tube is consisted of two layers. Outer layer is made from PLLA mesh, inner is from P(LA/CL) sponge form. Inner diameter is 2mm, outer is 3mm. And we had harvest and cultured Schwann cells from DRG of newborn rat, and seeded into tubes for 2 weeks. < Methods> We had implanted their tubes and seeded tubes into 12mm sciatic nerve gaps in Whister rat. At 4, 8, 12 weeks after implantation, their stiffness, flexibility and absorption were observed macroscopically and histologically. And also at 48 and 72 weeks tubes were observed macroscopically. Both tubes could maintain their cavities and their flexibility until 12 weeks macroscopically. However at 48 and 72 weeks, tubes were absorbed almost completely. Histologically inner layer was gradually absorbed since 4 weeks after implantation, however that was not disappeared completely at 12 weeks. Outer layer was almost remained at 12 weeks. Some macrophages were observed around PLLA mesh, but inflammatory cells were not migrated to among regenerating nerves. Our new bioabsorbable tube could be expected as reliable nerve conduit.
