腰椎手术后硬膜外腔瘢痕预防的实验研究

目的比较腰椎手术后硬膜外放置明胶海绵、几丁糖和高分子量的透明质酸钠 (sodium hyaluronate,HA)对术后硬膜外瘢痕形成的预防作用。方法 96只 Wistar大鼠被随机分成四组，每组 24只。一组为对照组，其它三组分别于单侧半椎板切除术和椎间盘破坏术关闭切口前在硬膜外腔放置明胶海绵、几丁糖和高分子量 HA。分别在术后第 2、 4、 8、 12周时，每组各取 6只大鼠进行大体标本、组织切片 (HE、 VG和免疫组化染色 )和透射电镜观察。对术后硬膜外瘢痕的多少和椎管的大小进行计算机图像分析和统计学处理。检测对照组和高分子量 HA组大鼠脑脊液中的 HA浓度。结果几丁糖和高分子量 HA组的硬膜外瘢痕比其它各组显著减少 (P< 0.05)；椎管的大小在各组各时段差异没有显著性意义；在各组各时段均可见到纤维环的环状纤维未能修复椎间盘手术带来的连续性中断。所有脑脊液标本中 HA浓度最高的 2例在 2周时的 HA组。结论几丁糖和高分子量 HA能减少后路腰椎间盘术后的硬膜外瘢痕的形成；评价材料对硬膜外瘢痕影响的同时，也要考虑到其对椎间盘破口愈合的影响；在硬膜外腔放置各种材料时应考虑到其对中枢神经系统的潜在影响。

An experimental study of inhibiting the epidural scar formation following lumbar spinal surgery

Objective To investigate the effects of absorbable gelatin sponge, chitosan and sodium hyaluronate(HA) on inhibition of postoperatively epidural scar formation in animal models with posterior discectomy and the concentrations of HA in the cerebral spinal fluid was also determined. Methods 96 Wistar rats older than 12 months were equally allocated into four groups. Each animal underwent a unilateral hemi-laminectomy and discectomy. Absorbable gelatin sponge, chitosan and HA were placed at the sites of surgery in three groups respectively. The fourth group undergone laminectomy and discectomy only, was served as control. At the time of 2,4,8,12 weeks postoperatively, 6 rats in each group were sacrificed for gross evaluation, histology and transmission electron microscope studies. The areas of epidural scar and spinal canal were measured by a computer image processor, and were compared statistically. The concentrations of HA in the cerebral spinal fluid in the HA groups and control groups were tested. Results The epidural scar areas in the chitosan and HA groups were significantly less than those in the control and absorbable gelatin sponge groups; no significant difference was found among the spinal canal areas of all the groups at different time phase; the compression and dislocation of the dura and spinal nerve roots and the discontinuity of the annulus fiber were observed in every group and time phase. The two cases with highest concentrations of HA were in the HA group at 2-week. Conclusion Chitosan and HA are able to inhibit the epidural scar formation after posterior discectomy. The healing of the annulus must be considered when evaluating the scar inhibition effects of materials. When the materials are placed in the epidural space, their effects on the central nervous system should be considered.