A BASIC STUDY ON THE DEVELOPEMENT OF NEW TECHNIQUE FOR SELECTIVE DORSAL ROOT BLOCKADE USING SPINAL ENDOSCOPY

1. 纤维脊柱内窥镜的发展：我们开发了用于脊柱间隙诊断和治疗的小直径内窥镜，我们打算看看我们是否可以使用这种内窥镜进行选择性后根阻滞。我们制作了两种内窥镜，外径1.8 mm和2.8 mm。后者有一个更大的冲洗腔，用于记录脊髓诱发电位的线型双极电极可以通过该腔。它们由成像纤维，光导，一个冲光管组成。小椎板切除术后，我们将这些内窥镜小心地插入硬膜外和蛛网膜下腔。硬膜外腔和蛛网膜下腔的结构，如脊髓、神经根、血管等清晰可见。一项新技术的发展，利用脊柱内窥镜识别背根作为传入神经从皮肤上的客观区域。我们进行了一项实验研究，在内窥镜下用脊髓诱发电位记录确定与肋间神经区相对应的背根。在内窥镜下观察硬膜外腔和蛛网膜下腔后，通过或平行于内窥镜腔内插入导线式记录电极，确定电极和背根的位置。我们将刺激电极放置在靠近目标根水平的下胸肋间神经上。我们尝试记录脊髓电位或肋间神经脉冲产生的背根电位。在目标根附近，将记录电极的水平由上向下改变，得到一系列电位。在实验的最后，我们确定了目标根和肋间神经的解剖位置。我们可以从硬膜外和硬膜下空间记录到非常靠近背根的诱发电位。我们发现从不同层次得到的诱发电位在形状上有特征差异。在离背根入口最近的电极处获得了最高的电位值。脊髓电位极性在该部位呈反向变化。因此，我们可以利用内窥镜技术配合电生理技术来识别客观根。少

1. Development of fiberoptic spinal endoscopy : We developed small diameter endoscopes for diagnostic and therapeutic use in the spinal space, and we intended to see if we can perform selective posterior root blockade using this endoscope. We made two types of endoscope, outer diameter 1.8 mm and 2.8 mm. The latter had a larger flush lumen through which a wire-type bipolar electrode for recording spinal evoked potentials can be passed. They consisted of the image fiber, light guide, a flush lumen. After small laminectomy, we inserted these endoscope carefully into epidural and subarachnoidal space. We could easily find and clearly observe structures of the epidural and subarachnoidal space, such as spinal cord, nerve roots and blood vessels.2. Development of a new technique using spinal endoscopy to identify the dorsal root as an afferent nerve from an objective area on the dermatome. : We performed a experimental study to determine endoscopically the dorsal root which correspond to th … More e specific intercostal nerve area using spinal cord evoked potential recording. After the observation of the epidural and subarachnoidal space with a endoscope, we inserted a wire type recording electrodes into the space through the lumen of endoscope or in parallel with it, and determined the location of electrodes and dorsal root. We located stimulation electrodes on lower thoracic intercostal nerves near the level of the objective root. We tried to record spinal cord potentials or dorsal root potentials generated by impulses from intercostal nerves. We obtained a series of potentials as changing the level of recording electrode from upward to downward region near the objective root. At the last of the experiment, we determined the anatomical location of the objective root and intercostal nerves. We could record evoked potentials very near to the dorsal root from both the epidural and subdural space. We found characteristic differences in shape of evoked potentials which obtained from different levels. Highest magnitude of the potential were obtained from the electrodes placed nearest to the site of entry of the dorsal root. The polarity of the spinal cord potentials changed inversely on this site. Thus we can identify the objective root using endoscopic technique coordinating with electro-physiological technique. Less