冷冻保存异体椎间盘移植的实验研究

Frozen Intervertebral Disc Allografting

目的 观察猴冷冻保存异体椎间盘移植后的Ｘ线、组织形态学、分子生物学、生物化学和生物力学的变化，探讨移植椎间盘的长期归宿及临床应用的可能性。方法１７只猴中的１２只随机分为０．５、１、１．５、２、６和２４个月组。移植椎间盘梯度降温至－１９６℃保存，术前复温后手术植入。结果Ｘ线显示无脱位，２４个月仍能维持正常高度的的６４．９％。术后２周仅在移植椎间盘终板下骨与宿主椎体骨界面区有轻度免疫排斥反应，４周时较明显，６周后逐渐减轻，８周逐渐趋向正常。分子生物学示移植组ＤＮＡ含量降低。细胞因子基因片段ｐｈＩＬ－６、ｐｈＩＬ－８、ｐｈＴＮＦ和ｉＩＮＯＳ早期较对照组增高，晚期与对照组比较，差异无显著性意义。生化结果示移植椎间盘髓核和纤维环代谢均有不同程度变化。生物力学结果示术后早期移植间盘在旋转、水平和轴向位移方面均有失稳倾向，但对腰椎整体活动无明显影响，术后中、晚期各方向稳定性恢复。结论 结合以往研究认为椎间盘移植有一定的临床应用前景。

Objective This study is a further exploration based on our previous studies of auto- andfresh allografting of intervertebral disc. Methods Twelve rhesus monkeys were divided into 6 groups. Thedonor disc tissue was procured from two monkeys and the procured disc tissues were then preserved at - 196degrees in liquid nitrogen. Osteotomies were performed at the endplates of L4-5 intervertebral disc, then, thefrozen discs were transferred in L4-5 spaces. The 6 groups of animals were sacrificed after 0. 5, 1, 1. 5, 2, 6and 24 months respectively. Results Radiograph demonstrated gradual loss of intervertebral disc height inthe early stage postoperatively, the disc height was still kept 64.9% of its original height at 24 months post-operatively. There was a mild immune rejection in the interface between allograft and recipient vertebral bodyfrom 2 to 8 weeks postoperatively. However, the allografts of intervertebral disc show edevidence ofHuman-aging-like' progressive disc degeneration 2 years after transplantation. DNA content was not normal,but RNA content was as normal as control. There was an increase of factors phIL-6, phIL-8, phTNF and iNOSin early stage postoperatively, then, there was a revision in late stage. Metabolic function of frozen allografts ofintervertebral discs was not as normal as control, but was still maintained in a new level. Biomechanically,hypermobility of allografted segments was observed in flexion-extension, lateral bending and rotation at 2months. then, there was a revision of hypermobility at 6 months postoperatively. Conclusion Combined withour previous work, the results indicate that allografts of intervertebral discs do have a clinical potential in thefuture.