不同容量胸段经椎间孔硬膜外注射阻滞范围的CT影像研究及诊断性阻滞的可行性分析

摘要 目的：探讨不同容量对胸段经椎间孔硬膜外注射（TFEI）药液扩散范围和镇痛效果的影响以及胸段TFEI用于诊断性阻滞的可行性。方法：选择2021年1月至2022年12月南京大学医学院附属鼓楼医院收治的胸段带状疱疹相关疼痛患者140例，随机分为4组，实施单次TFEI并分别注入不同容量含造影剂局麻药（A组：0.2 mL；B组：0.5 mL；C组：1.0 mL；D组：2 mL），CT扫描并观察造影剂在硬膜外向头侧、尾侧及总扩散节段，造影剂在椎间孔、同侧椎旁间隙、同侧及对侧硬膜外间隙扩散情况，判断是否为选择性神经根阻滞。评估注射前、注射后30分钟及24小时视觉模拟评分（VAS）。结果：头侧和尾侧扩散节段以及总扩散节段数，D组最多，A组最少（P<0.05）；C组、D组造影剂扩散≥3个节段发生率明显高于B组（P<0.05）；C组、D组病例造影剂扩散至同侧椎旁间隙和对侧硬膜外间隙的发生率明显高于A组、B组（P<0.05），仅A组37.1%的病例实现选择性神经根阻滞，其余各组均无选择性阻滞病例。注射后30分钟，C、D组VAS评分显著低于A、B组（P<0.05）；注射后24小时，D组VAS评分显著低于A、B组（P<0.05）。结论：胸段带状疱疹相关疼痛患者TFEI药液扩散范围随注射容量的增加而扩大，且在硬膜外倾向于头侧扩散，2 mL容量单次TFEI可阻滞3个以上的神经节段，获得良好的镇痛效果。胸段TFEI行诊断性阻滞的可行性较差。

CT Imaging Study of the Range of Block Transforaminal Epidural Injection Through Intervertebral Foramen in Different Volume Thoracic Segments and Feasibility Analysis of Diagnostic Block

ABSTRACT Objective: To explore the influence of different volume on the diffusion range and analgesic effect of transforaminal epidural injection (TFEI) through intervertebral foramen of thoracic segments and the feasibility of thoracic TFEI for diagnostic block. Methods: From January 2021 to December 2022, 140 patients with thoracic zoster associated pain who were admitted to Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University were selected, they were randomly divided into 4 groups, they were given a single TFEI and injected with different volumes of local anesthetics containing contrast agents (group A: 0.2 mL. Group B: 0.5 mL. Group C: 1.0 mL. Group D: 2 mL), CT scan was performed to observe contrast agent diffusion in the outward-dural cephalic, caudal and total diffusion segments, and contrast agent diffusion in the foramina, ipsilateral paravertebral space, ipsilateral and contralateral epidural space, to determine whether it was selective nerve root block. The visual analogue scale (VAS) was evaluated before injection, 30 minutes after injection and 24 hours after injection. Results: The number of cephalic and caudal diffusion segments and total diffusion segments was the highest in the group D, and the lowest in the group A (P<0.05). The incidence of contrast agent diffusion greater than or equal to 3 segments in the group C and D were significantly higher than that in the group B(P<0.05). The incidence of contrast media diffusion into the ipsilateral paravertebral space and contralateral epidural space in the group C and group D were significantly higher than that in the group A and group B (P<0.05). Only 37.1% of patients in the group A achieved selective nerve root block, and no cases of selective block were found in other groups. At 30 minutes after injection, the VAS score in the group C and D were significantly lower than that in the group A and B(P<0.05). At 24 hours after injection, the VAS score in the group D was significantly lower than that in the group A and B (P<0.05). Conclusion: In patients with thoracic zoster associated pain, the diffusion range of TFEI solution expands with the increase of injection volume, and tends to be cephalic diffusion in the epidural space. A single TFEI with 2 mL volume can block more than 3 nerve segments and obtain good analgesic effect. The diagnostic block of thoracic TFEI is not feasible.