醋酸纤维素和电解可控弹簧圈栓塞犬动脉瘤模型的比较

为探讨提高动脉瘤栓塞效果的途径 ,用显微吻合静脉袋移植的方法 ,建立犬的动脉瘤模型。分别以醋酸纤维素 (CAP)和可控弹簧圈 (WEDC)栓塞动脉瘤模型 ,在术后 2 4h、2周和 2月进行造影复查 ,并在栓塞后不同时期 ,分别抽取动物进行光镜、电镜和免疫组化的病理学研究。结果 :WEDC栓塞效果显著优于CAP(P <0 .0 1 ) ,且无相关并发症 ;CAP组 1 2枚动脉瘤中 ,4枚栓塞后出现载瘤动脉的狭窄或闭塞 ,2枚栓塞后 1周内破裂出血。病理检查发现WEDC动脉瘤腔内 2 4h后被弹簧圈和疏松的血栓所填充 ;CAP栓塞的动脉瘤腔内被CAP致密填塞 ,但早期动脉瘤壁急性化学损伤明显。从栓塞后 2周开始 ,2组动脉瘤颈部逐渐被新生的内皮组织所封闭 ,动脉瘤内部的血栓开始机化 ,但CAP组的炎症反应明显强于WEDC组 ,动脉瘤壁的损伤进一步加重 ,破裂动脉瘤的破裂点附近的瘤壁严重破坏。栓塞后 2个月 ,2组动脉瘤内的血栓都被被纤维组织代替 ,动脉瘤颈部被完整的内皮组织所封闭。结果提示 :WEDC仍然是目前安全可靠的动脉瘤栓塞材料 ,CAP因为其化学腐蚀作用和使用中控制困难 ,还有待于进一步改进。

Comparison of Cellulose Acetate Polymer and Coils for Treatment of Canine Aneurysmal Models

Electrolytic detachable coils have been used as main embolic materials for intracranial aneurysms. Liquid aneurysmal embolic materials represented by cellulose acetate polymer (CAP) are still controversial in use. In this research, the embolization result and pathological reaction after embolization of canine aneurysmal models with electrolytic detachable coils or CAP were observed. The comparison between the two materials might be helpful to explore the better one to improve the effect of intracranial aneurysms embolization. We made liquid material CAP, designed and constructed the self-made electrolytic detachable coils, which was named by Wu electrolytic detachable coil (WEDC). Canine aneurysmal models were constructed by anastomosis of venous pouches. The aneurysms were randomly grouped. The aneurysms were occluded with CAP and WEDC individually. Angiogram follow-ups were performed in 24 h, 2 weeks, and 2 months after embolization. The occluded aneurysms were dissected in each stage for light microscopic, electron microscopic, and histochemical research. We found that the result of embolization was significantly better with detachable coils than that with CAP (P<0.01). There was no complications related to embolization. But in CAP group with 12 aneurysmal models, the parent arteries were thrombosed or became stenosed after embolization in 4 aneurysms. Two CAP embolized aneurysms were ruptured in one week. Pathological examination showed that WEDC embolized aneurysms were filled with coils and loose thrombus around the coils and the CAP embolized aneurysms were densely packed with CAP mass 24 h after embolization. Acute chemical damage of the aneurysmal wall was found in early stage. The necks of aneurysms were gradually covered with newly formed endothelial layer and organization appeared inside the aneurysmal sac 2 weeks after embolization in both groups. Inflammatory cellular infiltration was much more prominent in CAP group than that in WEDC group. The damage to aneurysm wall in CAP group became more aggressive, and in some sections of the ruptured aneurysmal wall, the histological structure of aneurysmal wall was so badly damaged that no clear cell structure could be seen. Thrombus inside aneurysm was replaced completely by fibrous tissue and aneurysmal necks were covered with integrated endothelial tissue in both groups 2 months after embolization. But parts of coils might be exposed outside the endothelial layer in the coil embolization group. It is concluded that electrolytic detachable coils are still the most safe, efficient, and reliable method to embolize aneurysm. CAP should be improved greatly before it is widely used because of its difficulty to control and its strong chemical corrosion.