O'Neill Conor W, Liu Jane J, Leibenberg Ellen, Hu Serena S, Deviren Vedat, Tay Bobby K-B, Chin Cynthia T, Lotz Jeffrey C
Department of Radiology, University of California at San Francisco, San Francisco, CA 94143, USA.
Spine J. 2004 Jan-Feb;4(1):88-98. doi: 10.1016/s1529-9430(03)00423-6.
Discectomy is a surgical technique commonly used to treat bulging or herniated discs causing nerve root compression. Clinical data suggest discectomy may also help patients with contained discs and no clear neural compromise. However, the mechanisms of clinical efficacy are uncertain, and consequently bases for treatment optimization are limited.
To determine the effect of percutaneous plasma decompression on the histologic, morphologic, biochemical and biomechanical features of degenerating intervertebral discs.
An adult porcine model of disc degeneration was used to establish a degenerative baseline against which to evaluate discectomy efficacy.
Cytokines interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha were measured from tissue samples using enzyme-linked immunosorbent assay. Histology and morphology images were rated for degenerative findings (of cells and matrix) in both the nucleus and annulus. Proteoglycan content was determined, and intact specimen stiffness and flexibility were measured biomechanically. Magnetic resonance images were collected for biomechanical specimens.
Using a retroperitoneal surgical approach, stab incisions were made in four or five lumbar discs per spine in 12 minipigs. Animals were allocated into one of three groups: 6-week recovery, 12-week recovery and percutaneous plasma decompression using an electrosurgical device at 6 weeks with recovery for 6 additional weeks. Four additional animals served as controls.
Discs treated with discectomy had a significant increase in IL-8 and a decrease in IL-1 as compared with the 12-week, nontreated discs. There were no significant differences in morphologic and biomechanical parameters or proteoglycan content between treated discs and time-matched, nontreated discs.
Our results demonstrate that percutaneous plasma discectomy alters the expression of inflammatory cytokines in degenerated discs, leading to a decrease in IL-1 and an increase in IL-8. Whereas both IL-1 and IL-8 have hyperalgesic properties, IL-1 is likely to be a more important pathophysiologic factor in painful disc disorders than IL-8. Therefore, the alteration in cytokine expression that we observed is consistent with this effect as a mechanism of pain relief after discectomy. In addition, given that IL-1 is catabolic in injured tissue and IL-8 is anabolic, our results suggest that a percutaneous plasma discectomy may be capable of initiating a repair response in the disc.
椎间盘切除术是一种常用的外科技术，用于治疗导致神经根受压的椎间盘膨出或突出。临床数据表明，椎间盘切除术对包容性椎间盘且无明确神经损伤的患者也可能有帮助。然而，其临床疗效机制尚不确定，因此治疗优化的依据有限。
确定经皮等离子体减压对退变椎间盘的组织学、形态学、生物化学和生物力学特征的影响。
使用成年猪椎间盘退变模型建立退变基线，以评估椎间盘切除术的疗效。
采用酶联免疫吸附测定法从组织样本中检测细胞因子白细胞介素（IL）-1、IL-6、IL-8和肿瘤坏死因子（TNF）-α。对组织学和形态学图像进行评分，评估髓核和纤维环中细胞和基质的退变情况。测定蛋白聚糖含量，并通过生物力学方法测量完整标本的刚度和柔韧性。为生物力学标本采集磁共振图像。
采用腹膜后手术入路，在12只小型猪的每个脊柱的四到五个腰椎间盘上做穿刺切口。将动物分为三组之一：6周恢复组、12周恢复组和6周时使用电外科设备进行经皮等离子体减压并再恢复6周组。另外四只动物作为对照。
与12周未治疗的椎间盘相比，接受椎间盘切除术治疗的椎间盘IL-8显著增加，IL-1减少。治疗后的椎间盘与时间匹配的未治疗椎间盘在形态学、生物力学参数或蛋白聚糖含量方面无显著差异。
我们的结果表明，经皮等离子体椎间盘切除术改变了退变椎间盘中炎性细胞因子的表达，导致IL-1减少，IL-8增加。虽然IL-1和IL-8都具有痛觉过敏特性，但在疼痛性椎间盘疾病中，IL-1可能比IL-8是更重要的病理生理因素。因此，我们观察到的细胞因子表达变化与椎间盘切除术后作为疼痛缓解机制的这一效应一致。此外，鉴于IL-1在损伤组织中具有分解代谢作用，而IL-8具有合成代谢作用，我们的结果表明经皮等离子体椎间盘切除术可能能够启动椎间盘内的修复反应。
