Experimental study of vascuralized osteochondral allograft.

从近交系WKAH大鼠（RT 1 k）中取出具有股骨血管的远端股骨，并在使用可编程冷冻器逐渐冷冻后在-85 ℃下储存一周。在37 ℃解冻后，将移植物移植到另一只同种异体刘易斯大鼠（RT 11）腹壁的皮下袋中。第1组移植物经深低温保存后移植，第2组移植物经深低温保存后移植。吻合血管术后1周开始闭合。术后第5周，动脉和静脉完全闭合。第2组移植物经深低温保存后移植，术后每天使用环孢素10 mg/kg。闭塞动静脉通畅率100%。术后3 d，移植骨周围软组织血管保留，移植骨内无血管生成，组织学检查可见骨和骨髓细胞坏死。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所取代，表明带血管同种异体骨经冷冻保存后，其免疫原性并未减弱。在使用任何免疫抑制剂的移植骨中清楚地观察到蠕变替代。

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.