A study of induction of nerve regeneration using bioabsorbable tubes.

A silicone tube (S-tube) was packed with CPLA (copolymer of poly-L-lactide) fibers (S-tube+CPLA) or collagen fibers (S-tube+fiber). Two types of tube were prepared from a collagen sheet (Col-tube) and a bioabsorbable atelocollagen membrane for guided tissue regeneration (GTR-tube). They were packed with collagen fibers or films (Col-tube+fiber, GTR-tube+fiber and GTR-tube+film). Bridge grafting (15 mm in length) was performed with these tubes in a rat sciatic nerve model. Specimens were harvested after 8 weeks. Minifascicles were formed in the open space between the CPLA fibers in the S-tube+CPLA group. Regenerated axons were also formed in the degenerated collagen fibers in the S-tube+Col group. Immunocytochemistry evaluation revealed that Schwann cells invaded the space in the absorbing collagen fibers. Histologic analysis of the regenerated axons in the groups with Col-tubes or GTR-tubes revealed that both the Col-tube and the GTR-tube packed with collagen fibers were effective in providing a scaffold for regenerating nerve tissue.