新型主动脉弓开窗覆膜支架的动物实验研究

Animal experimental study of a new aortic arch fenestrated stent graft

目的通过大动物原位在体置入新型主动脉弓开窗覆膜支架,经长期饲养后评价其安全性与有效性。方法选用三只雄性健康大白猪(分别命名为PD01、PD05、PZ02),术前体重为86~150 kg,月龄为12~14个月。全麻插管下通过在猪的左胸第四肋间进胸,建立体外循环,切开主动脉植入主动脉弓开窗覆膜支架。术后随访6个月,通过血常规、血生化指标、超声、造影、解剖和病理等检查分析其安全性与有效性。结果3例动物术后红细胞、血浆血红蛋白、红细胞比积、血小板维持平稳。3例动物丙氨酸氨基转移酶术后即刻升高,天门冬氨酸氨基转移酶仅PZ02号升高,3例动物白蛋白术后即刻下降,血肌酐及尿素氮水平术后即刻升高,随时间推移,以上指标均恢复正常。在实验动物植入主动脉开窗覆膜支架后,心脏超声结果显示至终点的跨瓣压差和血流速度均未出现明显临床意义的主动脉瓣狭窄。数字减影血管造影检查结果显示,开窗覆膜支架的植入位置良好,未发生脱落、移位等不良现象。实验动物未出现明显的血栓形成、穿孔、感染等情况。结论新型主动脉弓开窗覆膜支架系统符合人造血管替代物的基本要求。其能够简化手术操作,缩短手术时间,减少术后并发症的发生。同时该支架系统具备良好的组织相容性和安全性。

Objective To evaluate the safety and efficacy of a novel aortic arch fenestrated membrane-covered stent graft implanted in situ in large animals after long-term maintenance.Methods Three healthy male Large White pigs(named PD01,PD05,PZ02 respectively),weighing 86-150 kg and aged 12-14 months,were selected.Under general anesthesia and intubation,thoracotomy was performed through the fourth intercostal space on the left side of the pigs to establish extracorporeal circulation.The aortic arch fenestrated covered stent was implanted by incising the aorta.Postoperative follow-up was conducted for 6 months,with safety and efficacy analyzed through routine blood tests,biochemical indices,ultrasonography,angiography,dissection,and pathology.Results In all three animals,postoperative levels of red blood cells,plasma hemoglobin,hematocrit,and platelets remained stable.The ALT of three animals elevated immediately after operation,the AST only elevated in PZ02.The albumin of three animals decreased and the levels of serum creatinine and blood urea nitrogen increased immediately after operation.All the indexes returned to normal along with time.Cardiac ultrasound results after the implantation of the aortic arch fenestrated covered stent showed no significant clinical signs of aortic valve stenosis in terms of transvalvular pressure gradient and blood flow velocity until the endpoint.Digital subtraction angiography revealed that the positioning of the fenestrated covered stents was satisfactory,with no instances of displacement or other adverse phenomena.No obvious thrombosis,perforation,or infection occurred in the experimental animals.Conclusion The novel aortic arch fenestrated covered stent system meets the basic requirements for artificial vascular substitutes.It can simplify surgical procedures,shorten operation time,and reduce the incidence of postoperative complications.Additionally,this stent system exhibits good tissue compatibility and safety.