Experimental study on the dynamics of lumbosacral nerve root circulation
Experimental study on the dynamics of lumbosacral nerve root circulation
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DOI：
10.1097/00007632-200002010-00007
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发表时间：
2000-02-01
期刊：
影响因子：
3
通讯作者：
Nakai, S
中科院分区：
文献类型：
--
作者：
Kobayashi, S;Yoshizawa, H;Nakai, S
研究设计.神经根循环动力学的实验研究。目标.目的：应用连续显像技术研究犬腰骶神经根循环动力学。神经根的血管分布主要从形态学方面进行了讨论，关于神经根的血液供应动力学还没有得到充分的说明。为了研究神经根中血流的方向，通过主动脉导管手动注射3 mL印度墨水后，立即使用电机驱动的相机拍摄了一系列马尾神经照片。观察神经根受压后血流方向的变化。实验中，将狗处死后，用Spalteholz技术清除神经根，以识别实验中观察到的血管。神经根动脉的血流在神经根近端呈下降趋势，远端呈上升趋势。这一观察结果支持了这样的建议，即在根动脉本身中存在所谓的血流分水岭。当神经根升动脉狭窄时，近端神经根血流向下。微血管造影显示神经根内血管丰富。在腰骶椎退行性变过程中，神经根中没有相对少血供的脆弱区域。因此，分水岭不太可能代表神经根中血流的薄弱点。
Study Design. Experimental investigation of the dynamics of nerve root circulation. Objectives. To study the dynamics of lumbosacral nerve root circulation by using seriography in dogs.Summary of Background Data. The vascular distribution to the nerve root has been discussed mainly from the morphologic aspects, and no adequate elucidation has been presented concerning the kinetics of the blood supply to the nerve root.Methods. To investigate the direction of blood flow in the nerve roots, a series of photographs of the cauda equina were taken using a motor-driven camera immediately after 3 mL of india ink was injected through the aortic catheter manually. The changes in the blood flow direction caused by compression of the nerve root also were observed. After the dog was killed, the nerve roots were cleared by the Spalteholz technique to identify the vessels observed during the experiment.Results. The blood flow in the radicular arteries was descending in the proximal part and ascending in the distal part of the nerve roots. This observation supports the suggestion that there is a so-called watershed of the blood flow in the radicular arteries themselves. However, when the ascending radicular artery of the nerve root was cramped, the radicular blood flow on the proximal side was downward. The microangiograms also showed that there were abundant anastomoses of intrinsic vessels in the nerve roots.Conclusions. There is no relatively hypovascular region in the nerve root that is vulnerable in the course of degenerative changes in the lumbosacral spine. Therefore, it is unlikely that the watershed represents a weak point of the blood flow in the nerve root.