脑动静脉畸形国产非黏附性液体栓塞材料EVAL的实验研究

The experimental study of EVAL （a non-adhesive fluid embolism material made in China ） in embolization of cerebral arteriovenous malformations

目的体外实验研究国产非黏附性液体栓塞材料次乙烯醇异分子聚合物（EVAL）的理化性质，以确定其是否适合脑血管畸形（AVM）的栓塞治疗。方法用旋转黏度计在不同温度下（25℃和37℃），测定不同浓度的EVAL分别含EVOH6％、8％和20％的黏度。将不同浓度（6％和8％）的EVAL在生理盐水液面以下约1cm处缓慢推出，测定其沉淀时间。用电子显微镜放大不同倍数，观察EVAL在体外析出后形成固体的超微结构。结果不同浓度的EVAL黏度有明显差别，随着EVAL浓度的增加黏度也增加。温度对EVAL的黏度有较大的影响，随着温度的升高黏度是下降的。沉淀时间则不受EVAL浓度和温度的影响。EVAL在体外析出后形成的固体在低倍电子显微镜下的结构呈海绵状，在高倍电子显微镜下呈带网的片状结构。结论不同浓度的EVAL具有不同的理化性质，因而适合不同类型的脑AVM的栓塞。

Objective Study the physiochemical characteristics of ethylene vinyl alcohol copolymer （EVAL） mixtures（ a non-adhesive fluid embolism material made in China） in vitro to determine the feasibility of the mixtures in embolization of cerebral arteriovenous malformations. Methods In various temperature（25~C ~1] 37~C ）, the EVAL solutions of various concentrations （ contain 6%, 8%, and 20% EVOH） were assayed by the rotational viscosimeter. The EVAL solutions of various concentrations （contain 6% and 8% EVOH） were pushed out slowly under 1 cm of physiological saline liquid level to assay the precipitation times. With the electronic microscope, the ultra-structure of EVAL solid in vitro was observed. Results The viscosities of different mixtures differed significantly. Along with the increase of EVAL concentrations, the viscosity also raised. The temperature of different mixtures differed significantly. Along with increase of EVAL temperature, the viscosity decreased. The precipitation times were not affected significantly by the concentration and temperature. The EVAL solutions might precipitate in vitro and become solid. With the low power electronic microscope, the EVAL solid was found to like sponge, and with the high power electronic microscope, the EVAL solid was found to like a laminar structure with many meshes. Conclusions Because of their different physiochemical properties, the various EVAL mixtures are suitable for the embolization of different types of cerebral arteriovenous malformations.