X线透视引导穿刺大鼠腰椎间盘建立椎间盘源性腰痛模型的实验研究

Establishment of discogenic low back pain model in rats by fluoroscopy-guided puncture of lumbar intervertebral disc: an experimental study

目的 探讨X线透视引导下穿刺大鼠腰椎间盘建立椎间盘源性腰痛(DLBP)动物模型的可行性。方法 将60只Sprague-Dawley大鼠随机分为DLBP组(X线透视引导下穿刺L4~5和L5~6,n=24)、假手术组(穿刺同层面椎旁肌,n=15)、正常组(不做任何处理,n=21);根据建模时间,再将每组大鼠平均分为30 d组、90 d组、180 d组。分别在建模后1、7、14、30、90、180 d进行行为学实验,评估大鼠步态功能、痛温觉阈值、轴性腰痛的改变;建模后30、90、180 d进行腰椎MR矢状位T2加权成像扫描,扫描完成后处死大鼠截取L4~5和L5~6椎间盘,行苏木精-伊红(HE)染色和番红O-固绿染色观察椎间盘退变程度。结果 DLBP组建模后大鼠步态障碍评分呈先增高后恢复再增高改变,至90、180 d与正常组和假手术组相比大鼠行为学表现为痛温觉阈值显著减低(均P<0.01)、轴性腰痛诱发的弯腰时间增加及挣扎时间减少(均P<0.05)。腰椎MR矢状位T2加权成像显示,建模后30、90、180 d正常组和假手术组大鼠腰椎间盘T2信号均无降低,而DLBP组腰椎间盘T2信号均降低,Pfirrmann分级以Ⅲ~Ⅳ级为主,呈中-重度退变。组织学结果显示,DLBP组大鼠椎间盘退变Masuda评分显著高于正常组和假手术组(均P<0.05)。结论 X线透视引导下腰椎间盘穿刺技术便捷、高效、微创,成功建立了DLBP大鼠模型。

Objective To explore the feasibility of establishing an animal model of discogenic low back pain(DLBP) in experimental rats by puncturing the lumbar intervertebral disc under the guidance of fluoroscopy. Methods A total of 60 Sprague-Dawley rats were randomly divided into DLBP group(fluoroscopy-guided puncture of L4-5 and L5-6, n=24), sham surgery group(puncturing the same level of paraspinal muscles, n=15), and control group(no any treatment measures, n=21). Each of the three groups was further divided into 30-day, 90-day, and 180-day subgroups. Behavioral assays were separately conducted at 1, 7, 14, 30, 90, and 180 days after model establishment to evaluate the changes in gait function, pain and temperature perception threshold, and axial low back pain in the experimental rats.Lumbar MRI sagittal T2-weighted imaging scans were separately performed at 30, 90 and 180 days after model establishment for the experimental rats of the corresponding subgroups, and after the scan was completed the experimental rats were sacrificed. The L4-5 and L5-6 discs were harvested, which were sent for HE staining and Safranin-0 fast green staining to check the degeneration degree of the discs. Results After modeling,the gait disorder scores of the rats in the DLBP group showed a changing pattern of first increasing, then recovering and again increasing. Compared with the sham surgery group and the control group, at 90 days and180 days after model establishment in the DLBP group, the behavior of rats showed a significant reduction in the threshold of pain and temperature perception(all P<0.01), the time of bending waist induced by axial low back pain was notably increased, and the time of struggling was remarkably reduced(all P<0.05). Lumbar MRI sagittal T2-weighted imaging showed that at 30 days, 90 days and 180 days after model establishment no reduction in T2 signal intensity of lumbar intervertebral discs was observed in the sham surgery group and in the control group. While the lumbar intervertebral discs T2 signal intensity was reduced in the DLBP group, and most rats the Pfirrmann classification was grade Ⅲ-Ⅳ, indicating a moderate-severe degeneration.Histological examination revealed that the Masuda score of intervertebral disc degeneration in the experimental rats of DLBP group was significantly higher than that in the sham surgery group and in the control group(all P<0.05). Conclusion The fluoroscopy-guided puncture of lumbar intervertebral disc is a convenient, efficient and minimally-invasive technique, with the help of this technique DLBP model is successfully established in experimental rats.(J Intervent Radiol, 2022, 31: 883-888)