Use of biological dural grafts in rabbit tarsus reconstruction

Objective To investigate the histocompatibility and histological outcomes of biological dural grafts in rabbit tarsus reconstruction. Methods Twenty New Zealand rabbits were divided into the biological dural graft group and allogenic sclera group (n=10 each) by random number table. The rabbits were subjected to total tarsus resection of the left lower eyelid (8 mm×6 mm in size) and implantation with biological dural grafts or allogenic sclera. The gross appearance of the surgical site and the corresponding surface of palpebrsl conjunctiva were observed in both two groups after surgery. Furthermore, HE staining of the graft tissues was performed at 2, 4, 6, 8, 12 weeks, and immunohistochemical assessment ofCD4+ and CD8+ at 4 and 8 weeks after surgery. Results There was no obvious rejection after implantation of the biological dural graft. Immunohistochemistry revealed less infiltration of CD4+ and CD8+ cells on biological dural grafts compared with allogenic sclera at 4 and 8 weeks after surgery [4 weeks after surgery: CD4+: (9±4)/vision vs (30±5)/vision, CD8+: (8±3)/vision vs (66±10)/vision; 8 weeks after surgery: CD4+: (9±4)/vision vs (61±10)/vision, CD8+: (7±2)/vision vs (27±7)/vision; all P＜0.01]. Histological study showed milder inflammation in biological dural graft as a host reaction to implantation. Early after surgery, newly developed fibrous tissues grew into the graft from periphery and transformed into collagen fibers. Along with neovascularization, the alignment of fibrous tissue in the graft was similar to the fiber bundles in normal tarsus. Conclusion Biological dural graft shows favorable histocompatibility after implantation into eyelids of rabbits, and therefore can be used as a tarsus-substituting bioscaffold for induced growth of new vessels and collagenous fiber. Key words: Blepharoplasty; Prostheses and implants; Biological dural graft; Tarsus defect; Rabbits