生物可吸收镁合金支架治疗20例兔模型颈内动脉瘤影像学和组织病理学研究

Bioabsorbable magnesium alloy stent in the treatment of internal carotid aneurysms:an angiographic and histopathology study of 20 rabbit model

目的构建生物可降解镁合金覆膜支架植入兔颈内动脉瘤模型,评价生物可降解镁合金覆膜支架在兔颈内动脉瘤模型的组织学反应,支架降解和内皮化情况。方法选取20只新西兰白兔构建颈内动脉瘤模型,通过外科手术于72 h内植入可降解镁合金覆膜支架。不同时间段行DSA血管造影检查评价载瘤动脉是否通畅及再狭窄率等情况。随访4个月,光镜和扫描电镜观察包括6和12个月的颈内动脉造影和血管内皮化及临床评估。结果共成功构建20例新西兰大白兔颈动脉瘤模型,顺利植入生物可降解镁合金覆膜支架。术后立即行血管造影,显示18例完全闭塞,仅2例动脉瘤腔内有部分血栓形成。光镜扫描下所有动脉瘤腔内均可见血栓形成,有些甚至发生机化。1周血管造影显示直段血管侧壁动脉瘤保持很好通畅,支架释放12个月后动脉瘤腔完全隔离。钼靶检测结果显示,镁合金覆膜支架在1 a后明显降解,期间未发现支架移位。术后1个月血管出现内皮化进程,术后6个月完成内皮化过程。结论应用可降解镁合金覆膜支架有助于治疗颈内动脉瘤。支架植入后颈动脉的通畅率得到了显著提高。镁合金覆膜支架具有可生物降解特性,随着时间的延长而降解,于术后6个月完成内皮化。

Objective To establish a biodegradable magnesium alloy stent graft for internal carotid artery aneurysms in rabbits,and to evaluate the histological response,stent degradation and endothelialization of the biodegradable alloy covered stent in the rabbit internal carotid artery aneurysm model.Methods Twenty New Zealand white rabbits were selected to establish rabbit models of internal carotid artery aneurysm by surgical operation.After implantation,a biodegradable magnesium alloy stent was implanted within 72 hours.DSA angiography was performed at different times to evaluate whether the carrying artery was smooth and restenosis rate.The endothelialization of the aneurysm cavity and blood vessel was observed by light and scanning electron microscopy.Results Biodegradable magnesium alloy covered stents were successfully implanted in 20 New Zealand white rabbits with the lateral common carotid artery aneurysm model.The model of internal carotid aneurysm maintained a good open cavity.Only 2 of the aneurysms were formed in the lumen of the aneurysm,and the common carotid artery was unobstructed.In all aneurysms,thrombosis was seen in all aneurysms,and some were even computerized.One week after implantation,angiography showed that the lateral wall aneurysm of the direct segment remained smooth,and the aneurysm cavity was completely isolated after the stent was released for 12 months.One year after implantation,molybdenum target detection showed the coated stent of magnesium alloy was degraded obviously and the contour disappeared.The endothelialization process began at 1 month after operation,and the endothelialization process was completed 6 months after operation.Conclusion The application of degradable magnesium alloy coated stent in the treatment of internal carotid artery aneurysm is very feasible.The patency rate of carotid artery stenting has been significantly improved.The magnesium alloy coated stent has the characteristics of biodegradation,which degraded with time and completed endothelialization at 6 months after the operation.