Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Cheng-Gong Road Section 2, Taipei 114, Taipei, 114, Taiwan, R.O.C.
Department of Orthopaedic Surgery, Tri-Service General Hospital, National Defense Medical Center, Cheng-Gong Road Section 2, Taipei 114, Taipei, 114, Taiwan, R.O.C.
Spine J. 2023 Jul;23(7):1079-1087. doi: 10.1016/j.spinee.2023.02.008. Epub 2023 Feb 18.
Chromodiscography is an integral part of full-endoscopic discectomy (FED), comprising ordinary discography with radiopacity produced by contrast medium and intradiscal stain for visualizing annular defects in the endoscopic field. Nevertheless, concerns remain about the cytotoxicity of the stains used. The study of their staining efficacy is also lacking.
To evaluate the feasibility of methylene blue, patent blue, and indigo carmine for intradiscal injection, investigate the effectiveness of each dye, and define critical concentration with adequate staining efficacy and tolerable cytotoxicity for use in chromodiscography during FED.
An experimental in vitro study.
Dye stock solutions were prepared from powder. The stock was diluted with culture medium or balanced saline and used for cytotoxicity or intervertebral disc staining assays, respectively. Bovine tails were obtained from the local slaughterhouse and functional spine units of intervertebral discs were acquired by transverse incision at the disc level. Each disc was punctured over the posterolateral aspect using a surgical knife to simulate an annular defect. The intradiscal injection was performed with each dye at different concentrations using a 22G needle from the contralateral aspect of the punctured site. Staining efficacy was quantified using ImageJ software. Primary cells of bovine tails were cultivated in each dye at different concentrations. Cytotoxicity was assessed 24 hours after stain exposure using the CCK-8 toxicity assay.
Staining efficacy and cytotoxicity were proportional to the concentration of tested dyes. Lower limits of concentration producing significant staining efficacy of indigo carmine, methylene blue, and patent blue were 0.25 mg/mL, 0.25 mg/mL, and 0.05 mg/mL, respectively. Compared with controls, concentrations showing significant toxicity for indigo carmine, methylene blue, and patient blue were 1 mg/mL, 0.5 mg/mL, and 2.5 mg/mL, respectively.
Patent blue can serve as a more suitable tissue stain than either indigo carmine or methylene blue due to the widest range of tradeoff concentration within 0.05 to 2.5 mg/mL.
Patent blue with the characteristic of good staining efficacy and lower cytotoxicity may be a promising option for chromodiscography during FED.
染色椎间盘镜检查术是全内镜下椎间盘切除术（FED）的重要组成部分，包括普通椎间盘造影术和对比剂产生的放射密度以及用于在内镜视野中显示环状缺陷的椎间盘内染色。然而，人们仍然对所用染料的细胞毒性表示担忧。对其染色效果的研究也缺乏。
评估亚甲蓝、专利蓝和靛蓝胭脂红用于椎间盘内注射的可行性，研究每种染料的效果，并确定具有足够染色效果和可耐受细胞毒性的临界浓度，以便在 FED 期间进行染色椎间盘镜检查。
体外实验研究。
从粉末中制备染料储备溶液。储备液用培养基或平衡盐稀释，分别用于细胞毒性或椎间盘染色测定。从当地屠宰场获得牛尾，并通过在椎间盘水平处的横切获得椎间功能单位。使用手术刀在每个椎间盘的后外侧穿刺点进行椎间盘内注射，模拟环状缺陷。使用来自穿刺部位对侧的 22G 针，用不同浓度的每种染料进行椎间盘内注射。使用 ImageJ 软件定量染色效果。在不同浓度的每种染料中培养牛尾的原代细胞，染色后 24 小时用 CCK-8 毒性测定法评估细胞毒性。
染色效果和细胞毒性与测试染料的浓度成正比。靛蓝胭脂红、亚甲蓝和专利蓝产生显著染色效果的浓度下限分别为 0.25mg/ml、0.25mg/ml 和 0.05mg/ml。与对照组相比，靛蓝胭脂红、亚甲蓝和专利蓝显示出显著毒性的浓度分别为 1mg/ml、0.5mg/ml 和 2.5mg/ml。
与靛蓝胭脂红或亚甲蓝相比，专利蓝可以作为一种更合适的组织染料，因为其在 0.05 至 2.5mg/ml 之间的权衡浓度范围内具有最宽的范围。
具有良好染色效果和较低细胞毒性的专利蓝可能是 FED 期间染色椎间盘镜检查的一种有前途的选择。
