SELECTIVE DORSAL ROOT BLOCKADE USING SPINAL ENDOSCOPY AND ELECTRO-PHYSIOLOGY

我们的目的是发展一种在内镜视野下选择性背根阻滞的方法。我们通过将内窥镜观察与脊髓电位测量相结合来实现这一目标。首先，我们开发了一种准确识别相应传入神经背根的方法。然后，我们在内窥镜下对根进行封锁，并评估封锁的选择性。方法：采用外径1.8 mm的内窥镜，该内窥镜由成像纤维、导光板和冲洗腔组成。对山羊进行麻醉和机械通气。下胸椎小椎板切除术后，我们将内窥镜小心地插入蛛网膜下腔，观察腔内结构。然后，我们将一个八极性导管型电极插入可视化空间以记录诱发电位。导管两极之间的距离为1cm。每根杆子都可以用记号来区分。利用内窥镜，我们试图更多地确定这些极和背根之间的空间关系。我们从导管的尖端依次选择相邻的两极对进行双极记录。为了刺激周围神经，我们将针状电极插入Th11和Th12肋间神经。通过刺激肋间神经，我们获得了脊髓背表面的连续电位记录。通过内窥镜和诱发电位的结合，我们试图确定相应传入神经的背根。在内镜下，我们将0.03或0.3 ml的3%利多卡因溶液应用于背根，作为Th11。我们获得了阻断后的诱发电位序列记录，并试图确定阻断的影响。在每次实验结束时，我们解剖动物，以确保肋间神经起源于根。结果：在内窥镜下，我们可以确定记录电极与背根的空间关系。诱发电位的形状根据根和极之间的相对位置有明显的变化。因此，我们可以用记录电极作为线索来识别背根和相应的传入神经。0.3 ml 3%利多卡因溶液阻断Th11根后，Th11和Th12刺激引起的电位均被抑制。0.03 ml注射后，同侧Th11刺激引起的电位被抑制，而对侧Th11和Th12刺激引起的电位没有变化。讨论与结论：通过内窥镜结合电生理技术，我们可以识别相应传入神经的背根。我们还可以利用这种技术来评估阻断剂的选择性。该方法可作为选择性背根阻滞的有效工具。少

We aimed to develop a method of the selective dorsal root blockade under the endoscopic visual field. We achieved this goal by combining endoscopic observation with spinal cord potential mesurement. First, we developled a method of accurately identifying the dorsal roots for the corresponding afferent nerves. Then, we applied blockade on the roots under endoscopic view and evaluated the selectivity of the blockade.Methods : We used an endoscope with an external diameter of 1.8 mm, which consisted of the image-fiber, light-guide and a flush lumen. Goats were anesthetized and mechanically ventilated. After small laminectomy on lower thoracic vertebrae, we inserted this endoscope carefully into subarachnoid space and observed structures in the space. Then we inserted an eight polar catheter-type electrode into the visalized space to record evoked potentials. The distance between the pole of the catheter was 1 cm. The each pole could be distinguished by marks. Using endoscopy, we tried to … More determine the spatial relationship between these poles and dorsal roots. We chose the neighboring pairs of poles sequentially from the tip of catheter for bipolar recording. To stimulate peripheral nerves, we inserted needle-type electrodes into Th11 and Th12 intercostal nerves. We obtained sequential recordings of potentials from dorsal surface of the cord evoked by stimulating each intercostal nerve. By combining endoscopy with evoked potentials, we tried to identify the dorsal roots for the corresponding afferent nerve. Under endoscopic view, we applied a dose of 0.03 or 0.3 ml of 3% lidocaine solution on the dorsal root regarded as Th11. We obtained sequential recordings of evoked potentials after blockade and tried to determine the effects of blockade. At the end of each experiment, we dissected the animal and ensured the intercostal nerve originating from the root.Results : With the endoscope, we could determine the spatial relationship between the recording electrode and dorsal roots. Shapes of evoked potentials changed characteristically according to the relative position between roots and poles. Thus we could identify the dorsal root and the corresponding afferent nerve using the recording electrode as a cue. After the Th11 root blockade with 0.3 ml of 3% lidocaine solution, potentials evoked by Th11 and Th12 stimulation was both depressed. After a dose of 0.03 ml injection, potentials evoked by ipsilateral Th11 stimulation was depressed without change on potentials by contralateral Th11 and Th12 stimulationDiscussions and Conclusions : By combining endoscopy with the electro-physiological technique, we could identify the dorsal roots for the corresponding afferent nerves. We could also evaluate the selectivity of the blockade using this technique. This method can provide a useful tool for selective dorsal root blockade. Less