消融髓核成形术中消融时间与椎间盘内压变化关系的实验研究

目的：研究消融髓核成形术中消融时间与椎间盘内压变化之间的量效关系，并观察消融后椎间盘髓核、终板形态学改变，探讨最佳的消融时间，为临床应用提供参考。 方法:选择2月龄的小型猪6只，平均体重22.5 kg，雌雄不拘，选取L1－S1共6个椎间隙进行消融，按消融时间的长短分10个不同时段测定消融后椎间盘内压，找出消融时间／椎间盘内压变化曲线。于不同消融时段随机从动物活体取出单个完整椎间盘，对髓核及终板进行HE染色，在普通光学显微镜下观察形态学改变。结果:实验动物正常椎间盘内压为（24.45±1.04） mmHg，椎间盘内压力符合正态分布，P>0.05。椎间盘内压随消融时间延长而逐渐降低，消融70 s后椎间盘内压达到平衡，70 s后椎间盘内压变化无统计学意义。病理显示消融后髓核组织出现空洞，消融至120 s时软骨终板完整，未见明显损伤。结论:椎间盘内压测量可以作为消融髓核成形术中椎间盘内压变化的监测手段，椎间盘内压变化与消融时间存在较明显的量效关系。消融70 s时椎间盘内压达到平台期，超过70 s后椎间盘内压的减少不再明显，消融区域未见扩大，软骨终板未见明显损伤。

Relationship between ablation time and changes of intra-disc pressure in nucleoplasty of isoionic radiofrequency ablation

AIM: To study the change of intra-disc pressure during nucleoplasty, and establish the relationship between accumulation of ablation time and degree of decompression. METHODS: Six pigs, aged two months, mean weight 22.5 kg were used in the experiment. Six disc spaces from Lumbar1 to Sacrum1 of each animal were selected for nucleoplasty. According to different ablation time, 10 groups of intra-disc pressure at certain time during the procedure were documented. Changes were recorded with ablation proceeding. According to certain time, discs and adjacent endplates were removed surgically from some segments at random for morphologic examination under light microscopy. RESULTS: Normal intra-disc pressure was (24.45±1.04) mmHg in control group. The difference of adjacent disc pressure was not statistically significant(P>0.05). The correlation of reduction of intra-disc pressure and accumulation of ablation time was positive. Compared with intra-disc pressure in control group, the pressure change of all ablation groups was statistically significant (P<0.05), and pressure reduction became very small after 70 s. Morphologic examinations showed that the treated area of nucleus pulposus appear vacant after ablation, and no evidence of damage to endplate at 120 s was observed. CONCLUSION: The intra-disc pressure measurement is useful for monitoring the degree of decompression during nucleoplasty. There is exact quantity-effect relation between ablation time and pressure reduction. When reduction of intra-disc pressure reaches platform after certain time during procedure, the change of pressure becomes very small and the incidence of injuries of adjacent endplates and other tissues may increase.