Compensatory neovascularisation in cauda equina nerve roots subjected to chroniccompression

本研究的目的是用专门设计的手术显微镜，在一个对照的实验装置中，在受压区的头部和尾部的尾部，用专门设计的手术显微镜来研究神经血管的形成。犬10只，体重7~12 kg，麻醉。狗俯卧放置，行第6腰椎和腰椎囊的椎板切除术。一个特别设计的可压平的塑料气球被轻轻地放置在第7腰椎的椎板下。气球被连接到ATS-1000压缩空气系统上。当球囊内压力增加时，球囊在第7腰椎椎板覆盖的椎管内压迫马尾神经。其中5只犬在100 mm汞压力下压迫120分钟，然后恢复神经根90分钟。手术显微镜下观察血流量及血管网分布情况。在剩余的…中另取5只狗，按压至10毫米汞柱，持续1周。在这个系列中，气球被连接到ATS-1000压缩空气系统，该系统现在被用来在10 mm Hg的输液压力下以缓慢的速度向气球中注入一种被称为Konnyaku的物质。这种物质最初是液体，但在10-20分钟内逐渐变得粘稠。当Konnyaku不再流入气囊时，维持输液压力30分钟，以补偿椎管内组织移位造成的压力损失。分别在椎板的头缘和尾缘结扎充气的气囊，并将位于结扎的头端和尾端的气囊部分切开并取出。在最初的手术七天后，两组的狗都被重新麻醉。结果：急性脊髓损伤后120分钟，马尾神经头部血管淤滞，毛细血管变窄，血流量减少。这些变化在加压松解后逐渐恢复。在马尾神经的尾部，有与神经根平行的血管。在这张幻灯片中，上血管是小动脉，下血管是小静脉。在120分钟的压迫过程中，尾部也可观察到静脉淤滞、毛细血管狭窄和血流量减少。与针刺组相似，静脉淤滞，毛细血管变窄，压迫区域的头尾血流量减少。然而，在所有这些慢性压迫的神经根中都可以看到明显更明显的血管网络，这与针灸形成了显著的对比。急性和慢性压迫均可引起不同程度的血管改变。然而，在慢性压迫的神经根中，有一个更发达的血管网络，这可能表明，由于神经根的内在血管系统的新生血管，慢性压迫的神经根可能会恢复功能。较少

The aim of this study was to study the nerve vasculature using a specially designedoperationmicroscope supplied with video camera in the area of the caudaeuina just cranial and caudal to the compression-zone in a controlled experimental set-up. Atotal of 10 dogs, bodyweight 7-12 Kg, were anaesthetized. The dogswere placed prone and a laminectomy of the 6th lumbar vertebra and the sac-rum was performed. A specially designedinflatable plastic balloon was gently placed under the lamina of the 7th lumbar vertebra. The balloon was connectedto a ATS-1000 compressed-air system. When the pressure in the balloon was increased, the balloon compressed the cauda equina in the segment of the spinal canal covered by the lamina of the 7th lumbar vertebra. In 5 of the dogs, compression at 100mm Hgwas maintained for 120 minutes and then the nerve roots were allowed to recover for 90 minutes. The blood flow and the distribution of vascular networks was studied by the operation microscope. In the remaini … More ng 5 dogs, compressionat 10 mmHg was maintained for one week. In this series, the balloon was connected to a ATS-1000 compressed-air system that now was used to infuse a substancecalled konnyakuinto the balloon at a slow rate at 10 mmHg infusion pressure. This substanceis first liquid but gradually beoomes viscous in 10-20 minutes. When there was no more flow of konnyakuinto the balloon, the infusion pressure was maintajned for 30 minutes to compensatefor pressure loss resulting from displacement of the tissues in the spinal canal. The inflated balloon was ligated, still under infusion, at the cranial and caudal border of the lamina, respectively, and the parts of the balloon locatedcranial and caudal to the ligatures were cut and removed. Seven days after the initial procedure, the dogs in both were reanesthetized. Similar to the acute series, the nerve root vasculature was studied in the cranial and the caudal segments of the cauda equina.Results : In the acuteseries, venousstasis, narrowing of capillaries, and a reduction of the blood flow were observed during the 120 minutes of compression in the cranial part of the caudaeuina. These changes gradually recovered after release of the compression. In the caudal part of the cauda equina, there were vessels running parallel to the nerve roots. The upper vessel is an arteriole and the lower vessel is a venule in this slide. Duing the 120 minutes of compression, venous stasis, narrowing of capillaries, and a reduction of the blood flow were also observed in the caudal part of the caudaequina. Similar to the acuteseries, there was venous stasis, narrowing of capillaries, and a reduction of blood flow bothcranial and caudal to the compression zone. However, a clearly more pronouncedvascular network was seen in all of these chronically compressed nerve roots, which contrasted significantly to the acuteseries. Both acute and chronic compressioninducedevident vascular changes. However, in the chronically compressednerve roots there was a more developedvascular network that might indicate that chronically compressed nerve roots mayrecover functionally due to neovascularisation of the intrinsic vasculature of the nerve roots. Less