SELECTIVE DORSAL ROOT BLOCKADE USING SPINAL ENDOSCOPY AND ELECTRO-PHYSIOLOGY

1)建立了准确识别相应传入神经后根的方法：内窥镜外径1.8 mm。对山羊进行麻醉和机械通气。在对下胸椎进行小范围椎板切除后，我们将内窥镜插入蛛网膜下腔，并观察该间隙的结构。然后将一个八极导管型电极插入可视化空间，记录诱发电位。每一根杆子都可以通过记号区分开来。在内窥镜下，我们试图确定这些极点与背根之间的空间关系。我们从导管尖端按顺序选择相邻的电极对进行双极记录。我们将电极插入Th11或Th12肋间神经。我们获得了刺激每条肋间神经诱发的脊髓背侧表面电位的连续记录。利用内窥镜可以确定记录电极与背根之间的空间关系。诱发电位的形状随根与极的相对位置而变化。将内窥镜技术与电生理技术相结合，以记录电极为线索，识别相应传入神经的背根。2)在内窥镜下对神经根进行阻断，评价阻断的选择性：在内窥镜下，将3ml、0.3ml和0.05ml 3%利多卡因溶液分别注入背根作为Th1。我们可以通过改变刺激和记录部位的诱发电位的顺序记录来确定阻滞的范围。我们还可以使用这项技术来评估封锁的选择性。该方法为选择性脊神经后根阻滞提供了一种有用的工具。

1) We developed a method of accurately identifying the dorsal roots for the corresponding afferent nerves.:We used an endoscope with an external diameter of 1.8 mm. Goats were anesthetized and mechanically ventilated. After small laminectomy on lower thoracic vertebrae, we inserted this endoscope into subarachnoid space and observed structures in the space. Then we inserted an eight polar catheter-type electrode into the visualized space to record evoked potentials. The each pole could be distinguished by marks. Using endoscopy, we tried to determine the spatial relationship between these poles and dorsal root. We chose the neighboring pairs of poles sequentially from the tip of catheter for bipolar recording. We inserted electrodes into Th11 or Th12 intercostal nerves. We obtained sequential recordings of potentials from dorsal surface of the cord evoked by stimulating each intercostal nerve. 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. By combining endoscopy with the electro-physiological technique, we could identify the dorsal roots for the corresponding afferent nerves using the recording electrode as a cue.2) We applied blockade on the roots under endoscopic view and evaluated the selectivity of the blockade.:Under endoscopic view, we applied a dose of 3 ml, 0.3 ml and 0.05 ml of 3% lidocaine solution on the dorsal root regarded as Th1 1. We obtained sequential recordings of evoked potentials after blockade and tried to determine the effects of blockade. We could determine the extension of blockade by obtaining sequential recordings of evoked potentials changing the site of stimulation and recording. We could also evaluate the selectivity of the blockade using this technique. This method can provide a useful tool for selective dorsal root blockade.