Experimental study of vascuralized osteochondral allograft.

从近交系WKAH大鼠（RT1k）中取出带股血管的股骨远端，用可编程冷冻机逐步冷冻后，在85℃下保存一周。37℃解冻后，移植物被移植到另一只异体lewis大鼠（rt11）腹壁的皮下袋中。同时将移植物的动、静脉与受体动物的股动脉、静脉吻合。第1组，移植物冷冻保存后移植。术后1周吻合血管开始闭合。术后第5周，动静脉完全闭合。未观察到新骨形成。第2组：冷冻保存后移植，应用环孢素10mg/kg/d。吻合的动、静脉通畅率100%。术后3 d，移植物周围软组织血管保留，但移植物骨内无血管存在，组织学上观察到骨和骨髓细胞坏死。术后1周，移植骨内再次出现血管。术后3周，坏死骨逐渐被新生骨取代。由此可见，带血管的同种异体骨移植物在低温保存后，其免疫原性并未减弱。使用任何免疫抑制剂都可以清楚地观察到移植物骨的蠕变取代。

Distal femur with femoral vessels was removed from inbreded WKAH rat (RT1k) and stored at-85 C for one week following gradual freezing using a programmable freezer. After thawing at 37 C, the graft was transplanted into a subcutaneous pocket on the abdominal wall of another allogeneic lewis rat (RT1l). At that time, artery and vein of graft were anastomosed to femoral artery and vein of the recipient animal.In the Group 1, the graft was transplanted after cryopreservation. Anastomosed vessels began to close one week postoperatively. At 5th week postoperatively, artery and vein were completely closed. No new bone formation was observed.In the Group 2, the graft was transplanted after cryopreservation and used cyclosporin with 10mg/kg/day. Patency rate of anastomosed artery and vein was 100%. At three days postoperatively, vasculature was preserved in soft tissue around the graft, however, no vasculature exised inside the grafted bone, and necrosis of bone and bone marrow cell was observed histologically. One week postoperatively, vasculature appeared again inside the grafted bone. After three weeks postoperatively, necrotic bone was replaced by new bone gradually.Form the above, it was concluded that immunogenecity of vascularized bone allograft was not weakened even after cryopreservation. Creeping substitution was clearly observed in the grafted bone using any immunosuppressive agent.