| Project/Area Number |
08457295
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General surgery
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| Research Institution | University of Tokyo |
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Principal Investigator |
CHINZEI Mieko TOKYO UNIV., LECTURER, 医学部・附属病院(分), 講師 (30165097)
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| Co-Investigator(Kenkyū-buntansha) |
TAGAMI Megumi TOKYO UNIV., ASSOCIATE PROFESSOR, 医学部・附属病院(分), 助教授 (90107657)
ABE Yusuke TOKYO UNIV., 医学部, 助手 (90193010)
CHINZEI Tsuneo TOKYO UNIV., 医学部, 助手 (20197643)
MABUCHI Kunihiko TOKYO UNIV., PROFESSOR, 先端科学技術研究センター, 教授 (50192349)
IMACHI Kou TOKYO UNIV., PROFESSOR, 医学部, 教授 (10010076)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 1997: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1996: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | DORSAL ROOT BLOCKADE / SPINAL ENDOSCOPY / SPINAL CORD POTENTIAL |
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| Research Abstract |
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
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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 stimulation
Discussions 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
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