不同硬膜外覆盖材料对预防大鼠脊柱术后瘢痕增生和粘连的机制

Effectiveness of different epidural coverage materials for preventing postoperative scar hyperplasia and dural adhesion in spine

目的分析明胶海绵、牛跟腱提取胶原及聚酯尿烷纤维3种常用硬膜外覆盖物预防大鼠椎板切除术后硬膜外瘢痕粘连的作用及其机制。方法48只成年Wistar大鼠切除L2~5椎板制作椎板切除模型,根据不同覆盖材料随机数字表法分为4组(每周12只):空白组(A组)、明胶海绵组(可吸收,B组)、聚酯尿烷纤维组(不可吸收,C组)和牛跟腱提取胶原组(可吸收,D组)。于术后4周及12周取手术区域脊柱组织行大体观察(Rydell瘢痕粘连程度评级标准)、组织学观察(Nussbaum标准);并检测硬膜周围组织中碱性成纤维细胞生长因子(bFGF)、转化生长因子β1(TGF‑β1)、血管内皮细胞生长因子(VEGF)等3种瘢痕增生相关细胞因子的表达情况。分析比较各组各指标间的差异。结果48只大鼠全部存活。4周和12周大体观察和组织学结果显示明胶海绵和牛跟腱提取胶原组不存在硬膜粘连,聚酯尿烷纤维组硬膜存在粘连,空白对照组粘连程度较重且存在脊髓受压。可吸收材料组与不可吸收组Rydell评级和Nussbaum组织学评分间差异具有统计学意义(均P<0.05)。在4周和12周可吸收材料组的bFGF、TGF‑β1、VEGF等3种细胞因子的表达水平均较不可吸收组低,差异均有统计学意义(均P<0.01),12周时免疫荧光实验证实bFGF、TGF‑β1、VEGF表达在明胶海绵组(9.81±0.81、12.42±2.35、8.63±1.76)和牛跟腱提取胶原组(12.70±2.02、8.23±1.03、10.19±2.67)均较聚酯尿烷纤维组(33.94±2.03、30.29±2.76、25.79±1.21)低,组间差异均有统计学意义(均P<0.01)。结论牛跟腱提取胶原和明胶海绵可有效减轻脊柱术后瘢痕的增生及硬脊膜粘连。

Objective To analyze the effects and mechanisms of three commonly used epidural coverings,gelatin sponge,bovine Achilles tendon extract collagen and polyester urethane fiber,in preventing epidural scar adhesions after laminectomy in rats.Methods Forty‑eight adult Wistar rats were excised from L2 to L5 lamina to establish laminectomy models,and were divided into four groups with random number table according to different covering materials(12 rats in each group):blank group(group A),gelatin sponge group(absorbable,group B),polyester urethane fiber group(non‑absorbable,group C)and bovine Achilles tendon extract collagen group(absorbable,group D).At 4 and 12 weeks postoperatively,the spinal tissues of the operated area were taken for gross observation(Rydell scar adhesion rating criteria)and histological observation(Nussbaum criteria);and the expression of three scar proliferation‑related cytokines,basic fibroblast growth factor(bFGF),growth transforming factorβ1(TGF‑β1)and vascular endothelial growth factor(VEGF),were measured in the peridural tissues.The differences between the indices in each group were analyzed and compared.Results All 48 rats survived,and gross and histological findings at 4 and 12 weeks showed no dural adhesions in the gelatin sponge and bovine Achilles tendon extract collagen groups,adhesions in the polyester urethane fiber group,and heavy adhesions and spinal cord compression in the blank control group.There were significant differences in the Rydell grade and Nussbaum histological score between the absorbable material group and the non‑absorbable group(both P<0.05).Western protein blotting at 4 and 12 weeks confirmed that the expression levels of three cytokines,including bFGF,TGF‑β1,and VEGF,were lower in the absorbable material group than those in the non‑absorbable group(all P<0.01).Immunofluorescence tests at 12 weeks confirmed that the expression of bFGF,TGF‑β1 and VEGF were all lower in the gelatin sponge group(9.81±0.81,12.42±2.35,8.63±1.76)and the bovine Achilles tendon extract collagen group(12.70±2.02,8.23±1.03,10.19±2.67)than those in the polyester urethane fiber group(33.94±2.03,30.29±2.76,25.79±1.21)(all P<0.01).Conclusions Bovine achilles tendon extract collagen and gelatin sponge can effectively reduce the hyperplasia of scar and dural adhesions after spinal surgery.