Objective

To evaluate an approach to the canine lumbar dorsal root ganglion (DRG), a significant contributor to the pain pathway, using new methylene blue staining.

Study design

Prospective randomized study.

Animals

A total of three Beagle dog cadavers weighing 10.4 ± 0.7 kg (mean ± standard deviation).

Methods

Bilateral third to fifth lumbar DRG approaches were performed in three dog cadavers positioned in sternal recumbency. The mammillary process was palpated, and a 22 gauge spinal needle was inserted through the skin 1 cm lateral to the process and directed towards the median plane at a 45° angle to the dorsal plane. The needle was advanced along the transverse plane until touching bone, or a popping sensation was detected. Under fluoroscopic guidance, the position of the needle tip was adjusted to be in the cranioventral part of the intervertebral foramen. The location of the needle was confirmed by demarcation of the nerve roots after iohexol (0.1 mL) injection. For evaluation of the DRG approach, new methylene blue (0.1 mL) was injected. Subsequently, anatomical dissection of the area was performed. The DRG staining was scored as follows: 0, no staining; 1, partial (<50%); 2, partial (≥50%); and 3, complete staining. Comparisons among the staining scores of the third to fifth DRG were assessed with the Friedman test.

Results

Staining score 3 was achieved in 14 of 18 (77.8%) sites. Staining scores 2, 1 and 0 were identified at two, one and one of the 18 sites, respectively. No significant difference was noted in the staining scores among the third to fifth DRGs (p = 0.78).

Conclusions and clinical relevance

The technique used for DRG injections achieved adequate DRG staining, supporting use of the fluoroscopy-guided approach to the canine lumbar DRG.

中文翻译：

---

荧光镜引导下的方法治疗狗的腰背根神经节：比格犬的尸体研究。

目的

为了评估犬腰椎背根神经节（DRG）的方法，该方法使用新的亚甲基蓝染色，是疼痛路径的重要贡献者。

学习规划

前瞻性随机研究。

动物

总共三只比格犬尸体，重10.4±0.7千克（平均±标准差）。

方法

在位于胸骨卧位的三只狗尸体上进行双侧第三至第五腰椎DRG入路。触诊乳突，将22号脊柱针穿过该过程横向1 cm的皮肤，并以与背平面成45°角的方向指向正中平面。针头沿横向平面前进，直到接触骨骼或检测到爆裂感。在荧光检查的指导下，将针尖的位置调整为在椎间孔的颅腹部分。注射碘海醇（0.1 mL）后通过神经根的分界确认针的位置。为了评估DRG方法，注入了新的亚甲蓝（0.1 mL）。随后，对该区域进行解剖解剖。DRG染色的评分如下：0，无污染；1，部分（<50％）; 2，偏（≥50％）; 3，完全染色。用弗里德曼检验评估第三至第五DRG的染色评分之间的比较。

结果

18个站点中的14个（77.8％）达到了染色得分3。分别在18个地点的两个，一个和一个处确定了染色分数2、1，0。第三至第五个DRG之间的染色分数没有显着差异（p  = 0.78）。

结论与临床意义

用于DRG注射的技术可实现足够的DRG染色，从而支持对犬腰部DRG进行荧光检查引导的方法。