Morphological changes of nerve by nerve block

将高剂量局麻药5%利多卡因和半永久性神经溶解剂99%酒精注入眶下孔，观察从神经损伤到再生的形态学变化过程。并检查眶下神经从眶下孔到周围触须的正常神经内血管化。药物输注后，酒精组和利多卡因组均未见明显变化。药物输注后1天，酒精组和利多卡因组均显示神经束内有髓神经纤维几乎完全破坏。在酒精组，这种破坏状态在手术后持续了一个月，但在利多卡因组，到手术后第三天，破坏的有髓神经纤维的数量减少了50%。在酒精组，术后2 ~ 3个月，75%的有髓神经纤维长度小于5μm， 20%的有髓神经纤维长度大于5μm。术后6个月，粗髓神经纤维占70%，细髓神经纤维占30%，与对照组接近。在利多卡因组，从术后1周到术后6个月，小于5μm的有髓神经纤维百分比随时间逐渐减少，大于5μm的有髓神经纤维百分比增加。大约5%仍被破坏。光学显微镜观察正常小鼠眶下神经眶下孔附近的横切面，可见神经纤维束（直径约150μm）被神经膜外膜覆盖，由近端向外周延伸，随着分支的增多而增多。在眶下孔附近被神经膜包围的神经束内，分布有少量血管。随着神经束的分支和伸展，血管也分支，在每个神经束中提供一条血管。神经外膜和神经会膜之间有多根血管。神经束内的血管由细分支组成，与神经会膜外的血管相通。神经束被与毛细血管、小动脉和小静脉相通的血管网络所包围。部分血管在神经束内呈链状分布。在眶下神经外周部分，神经束内的血管先于神经进入触须而出。神经末梢神经束内未见血管。少

A high dose local anesthetic, 5% lidocaine, and a semi-permanent neurolytic agent, 99% alcohol, were infused into the infraorbital foramen, and the morphological change progression from nerve injury to regeneration was observed. And the normal intraneural vascularisation of the infraorbital nerve from the infraorbital foramen to the peripheral vibrissae were examined.Immediately post drug infusion, there were no significant changes seen in either the alcohol or the lidocaine groups. One day post drug infusion, both the alcohol group and lidocaine group showed near complete destruction of the myelinated nerve fibers within the fascicle. In the alcohol group, this destructed state continued for one month post-procedure, but in the lidocaine group, by the third day post-procedure, the number of destructed myelinated nerve fibers decreased by 50%. In the alcohol group, from 2 months post-procedure to 3 months post-procedure, 75% of the myelinated nerve fibers were less than 5μm in length, … More while 20% were thick myelinated nerve fibers greater than 5μm. By 6 months post-procedure, thick myelinated nerve fibers were 70%, while thin nerve fibers were 30%, which are close to values found in the control group. In the lidocaine group, from one week post-procedure to 6 months post-procedure, the percentage of myelinated nerve fibers less than 5μm gradually decreased over time, while the percentage of fibers greater than 5μm increased. Approximately 5% remained destructed. Optical microscopic observation of the cross-section of normal mouse infraorbital nerve near the infraorbital foramen revealed nerve fiber fascicles(about 150μm in diameter) covered with epineurium extending from proximal to peripheral areas, increasing in number as they branched. In the nerve fascicle surrounded by the perineurium near the infraorbital foramen, a few blood vessels were distributed. As the nerve fascicle branched and extended, the blood vessels also branched, providing one blood vessel in each nerve fascicle. There were multiple blood vessels in between the epineurium and perineurium. The blood vessels in nerve fascicles consisted of thin branches communicating with blood vessels outside of the perineurium. Nerve fascicles were surrounded by networks of blood vessels communicating with capillaries, arteriolae and venulae. Some blood vessels showed chain-like distribution in nerve fascicles. In the peripheral part of the infraorbital nerve, the blood vessel in the nerve fascicle exited before the nerve entered a vibrissa. There were no blood vessels in the nerve fascicle at the nerve terminal. Less