Compensatory neovascularisation in cauda equina nerve roots subjected to chroniccompression

本研究的目的是在一个控制的实验装置中，使用一种特殊设计的带有摄像机的手术显微镜来研究神经脉管系统，该显微镜位于尾尾肌的头部和尾侧压迫区。麻醉犬10只，体重7 ~ 12 Kg。将狗置于俯卧位，并对第6腰椎和骶椎进行椎板切除术。将一个特别设计的可充气塑料球囊轻轻放置在第7腰椎椎板下。气球与ATS-1000压缩空气系统相连。当球囊内压力增加时，球囊在第7腰椎椎板覆盖的椎管段内压迫马尾。其中5只犬在100mm高压下压迫120分钟，然后让神经根恢复90分钟。手术显微镜下观察血流及血管网分布。其余5只犬，维持10 mmHg压力1周。在这个系列中，气球连接到ATS-1000压缩空气系统，该系统现在用于在10毫米汞柱的注射压力下以缓慢的速度将一种称为konnyakuu的物质注入气球。这种物质最初是液体，但在10-20分钟内逐渐变得粘稠。当不再有konnyakuin流入球囊时，维持输注压力30分钟，以补偿椎管组织移位造成的压力损失。将仍处于输液状态的充气球囊分别结扎在椎板的颅缘和尾缘，将位于结扎处颅缘和尾缘的球囊切除并移除。初次手术后7天，两家医院的狗都被再次麻醉。与急性系列相似，在马尾的颅和尾段研究了神经根血管系统。结果：在脑脊膜颅部受压120分钟期间，观察到静脉淤积，毛细血管狭窄，血流量减少。这些变化在解除压迫后逐渐恢复。在马尾尾部，有平行于神经根的血管。上面的血管是小动脉下面的血管是小静脉。在120分钟的压迫过程中，还观察到马尾尾部静脉淤滞，毛细血管狭窄，血流量减少。与急性发作相似，静脉淤滞，毛细血管狭窄，颅侧和尾侧压迫区血流减少。然而，在所有这些长期受压的神经根中可见明显更明显的血管网络，这与针孔组形成明显对比。急性和慢性压迫均可引起明显的血管改变。然而，在慢性受压的神经根中，有一个更发达的血管网络，这可能表明慢性受压的神经根可能由于神经根固有血管的新生而恢复功能。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