Objective

To describe a novel in-plane ultrasound (U/S)-guided temporal approach to peribulbar block in dogs.

Study Design

Prospective experimental cadaver study.

Animals

A group of 10 Beagle cadavers.

Methods

After describing the U/S anatomy, peribulbar injection was performed bilaterally in 10 thawed Beagle cadavers by two randomly assigned operators. A 5–8 MHz microconvex U/S probe was positioned caudal to the orbital ligament in the longitudinal plane. Using an in-plane technique, methylene blue dye was injected in five dogs (10 eyes total), while methylene blue dye and iohexol contrast mixture (50:50) were injected in the remaining five dogs. Injection volume was 0.2 mL cm⁻¹ of cranial length. A computed tomography (CT) scan was performed on dogs injected with dye and contrast to identify spread of contrast. Dissection to visualize dye spread in the orbit was performed in all dogs. Injection success was defined as spread of contrast into the peribulbar space. The pattern of distribution of contrast-dye was also assessed. Comparisons between operator and bilateral injections were assessed using a Student t test (p < 0.05). All other data are reported as number (n/N) and percentage (%).

Results

Peribulbar spread was noted in 19/20 injections (95%) on dissection. CT imaging (five dogs) illustrated peribulbar contrast spread in 9/10 injections (90%), with mixed peribulbar/retrobulbar spread for the remaining injection. Contrast was present at the rostral alar foramen in 4/10 (40%) injections, orbital fissure in 5/10 (50%), oval foramen in 1/10 (10%), maxillary nerve in 3/10 (30%) and intracranial in 5/10 (50%). Coverage of the maxillary nerve was noted on 3/20 (15%) injections on dissection. No further dye spread was noted.

Conclusions and clinical relevance

This technique demonstrated peribulbar spread of injectate in 100% of injections for the 10 canine cadavers studied. Further studies are required to evaluate this technique clinically.

中文翻译：

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犬的平面内超声引导球周阻滞：一项解剖尸体研究

客观的

描述一种新颖的平面内超声 (U/S) 引导的犬球周阻滞时间方法。

学习规划

前瞻性实验尸体研究。

动物

一组 10 具比格犬尸体。

方法

在描述了 U/S 解剖结构后，两名随机分配的操作员在 10 具解冻的 Beagle 尸体中进行了双侧球周注射。5-8 MHz 微凸 U/S 探针位于纵向平面中眶韧带的尾部。使用平面内技术，将亚甲蓝染料注射到五只狗（共 10 只眼睛）中，而将亚甲蓝染料和碘海醇对比剂混合物 (50:50) 注射到其余五只狗中。进样量为 0.2 mL cm ^{- 1}颅长。对注射了染料和造影剂的狗进行计算机断层扫描 (CT) 扫描，以确定造影剂的扩散。对所有狗进行解剖以观察眼眶中的染料扩散。注射成功被定义为对比剂扩散到球周空间。还评估了对比染料的分布模式。使用学生t检验 ( p < 0.05)评估操作员和双侧注射之间的比较。所有其他数据均以数字 ( n/N ) 和百分比 (%) 的形式报告。

结果

19/20 次注射 (95%) 在解剖时注意到球周扩散。CT 成像（五只狗）显示了 9/10 注射（90%）中球周对比剂扩散，其余注射混合球周/球后扩散。4/10 (40%) 注射的鼻翼孔形成对比，5/10 (50%) 的眶裂，1/10 (10%) 的卵圆孔，3/10 (30%) 的上颌神经和颅内 5/10 (50%)。在解剖时注射 3/20 (15%) 时注意到上颌神经的覆盖。没有注意到进一步的染料扩散。

结论和临床相关性

该技术证明了在 100% 注射中注射液在 10 具研究犬尸体中的球周扩散。需要进一步的研究来临床评估这种技术。