Objective

To describe the gross and microscopic anatomy of the sciatic nerve paraneural sheath and to report an ultrasound (US)-guided subparaneural approach to the sciatic nerve in dogs, comparing two different volumes of injectate.

Study design

Prospective, randomized, anatomical study.

Animals

A group of nine middle-sized adult Mongrel canine cadavers (18 limbs).

Methods

The sciatic nerves of three pelvic limbs of two canine cadavers were identified, exposed and isolated between the greater trochanter and the popliteal fossa for gross anatomical and microscopic examination. An additional three pelvic limbs were surgically dissected on the lateral surface of the limb; the sciatic nerves were isolated, and a 26 gauge over-the-needle catheter was inserted through the paraneural sheath under direct visualization. A methylene blue solution was then slowly injected into the subparaneural compartment through the catheter under US visualization using an 8–13 MHz linear-array transducer. Subsequently, 12 pelvic limbs (six cadavers) were randomly allocated to one of two groups; using US-guided percutaneous subparaneural approach, either 0.1 or 0.05 mL kg^–1of a 1:1 solution of methylene blue and 0.5% bupivacaine was injected. The spread of the dye solution and the amount of nerve staining were macroscopically scored. The stained sciatic nerves with their sheaths were then harvested for microscopic examination.

Results

The paraneural sciatic nerve sheath was easily identified distinct from the nerve trunk both macroscopically and with US visualization, and microscopically. Complete staining was achieved in five of six (83.3%) sciatic nerves in each group; no difference was found in the amount of staining between the two groups. Microscopically, no signs of sciatic nerve intraneural injection were observed.

Conclusions and clinical relevance

The US-guided subparaneural injection of 0.05 mL kg^–1 of a dye injectate resulted in satisfactory nerve staining without evidence of sciatic nerve intraneural injection.

中文翻译：

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超声引导下犬坐骨神经的神经下入路：尸体研究

客观的

描述坐骨神经旁神经鞘的大体和微观解剖结构，并报告对狗的坐骨神经进行超声 (US) 引导的神经旁方法，比较两种不同体积的注射液。

学习规划

前瞻性、随机、解剖学研究。

动物

一组九具中等大小的成年杂种犬尸体（18 条肢体）。

方法

在大转子和腘窝之间识别、暴露和分离两具犬尸体的三个骨盆肢的坐骨神经，用于大体解剖学和显微镜检查。另外三个骨盆肢体在肢体的侧面进行了手术解剖；分离坐骨神经，并在直视下通过旁神经鞘插入 26 号针头导管。然后使用 8-13 MHz 线阵换能器在 US 可视化下通过导管将亚甲蓝溶液缓慢注入神经旁室。随后，将 12 个骨盆肢体（6 具尸体）随机分配到两组中的一组；使用超声引导下经皮神经旁入路，0.1 或 0.05 mL kg ^–1注射亚甲蓝和 0.5% 布比卡因的 1:1 溶液。对染料溶液的扩散和神经染色的量进行宏观评分。然后收获染色的坐骨神经及其鞘用于显微镜检查。

结果

神经旁坐骨神经鞘很容易在肉眼观察和超声观察以及显微镜下与神经干区分开来。每组 6 条坐骨神经中有 5 条（83.3%）完全染色；两组间染色量无差异。在显微镜下，没有观察到坐骨神经神经内注射的迹象。

结论和临床相关性

US 引导下神经内注射0.05 mL kg ^–1染料注射液，神经染色令人满意，没有坐骨神经神经内注射的证据。