生物可吸收铁基肺动脉支架的动物实验研究

Experimental study of bioabsorbable iron-based pulmonary artery stent

目的了解生物可吸收铁基肺动脉支架在猪肺动脉中的可吸收降解性和生物安全性。方法小型猪19只应用随机数字表进行随机分组。其中3只为空白对照组；10只为支架植入A组，于肺动脉内仅植入1个支架；6只为支架植入B组，于肺动脉内分别植入2个支架。术后进行随访至24个月。统计学方法采用随访资料多个时间点多组处理的重复测量资料方差分析。结果术后随访肺动脉血流速度（F分组×时间=1．06，P=0．40）、右心室压力（F分组×时间=0．58，P=0．86）各组问比较差异无统计学意义，提示未发生血管再狭窄情况。肺动脉管径扩张率支架植入A、B组与对照组之间比较差异有统计学意义（F分组=3．57，P=0．05；F时间=12．89，P〈0．001；F分组×时间=2．99，P=0．03），提示在随访期内支架对血管能维持较好的扩张作用。血清铁水平各组比较差异无统计学意义（F分组×时间=0．94，P=0．52）。随访期内所有试验动物均成活至随访终点，均未出现支架不良反应造成的严重不良事件。结论生物可吸收铁基支架在动物体内发生一定程度的降解并有较好的生物安全性与稳定性。

Objective To monitor the degradation and bio-safety features of the bioabsorbable iron-based stent planted in the pig pulmonary artery. Methods A total of 19 miniature pigs were randomly assigned into 3 groups. Three cases were assigned as the control group; ten cases were assigned as stent implantation group A with one stent implanted in the pig pulmonary artery; the other six cases were assigned as stent implantation group B with two stents implanted in the pig pulmonary artery. Follow-up studies for 24 months were conducted in all cases. Repeated measures ANOFA were used to collect and analyze statistical processing data at multiple time points of the follow-up. Results After surgery, pulmonary artery blood flow velocity and right ventricular pressure were measured by echocardiography and cardiac catheterization. There was no significant difference in pulmonary artery blood flow velocity（ Fgroup×time= 1.06,P = 0.40） and right ventricular pressure （ Fgroup×time=0. 58, P = 0.86 ） among each group, and no vascular re- narrow circumstance was indicated. Pulmonary artery diameter expansion rate between stent group and control group was statistically different （ Fgroup= 3.57, P = 0.05 ; Ftime= 12.89, P 〈 0. 001 ; Fgroup×time= 2. 99, P = 0.03 ）, suggesting that the stent could maintain a good expansion of the role of vascular in the follow-up period even though in degradation. Difference in the level of serum iron concentrations among the groups was not statistically significant （ Fgroup×time= 0.94, P = 0.52）, suggesting that there was no evidence of iron overload. All animals survived to the follow-up endpoint, and no serious side effects caused by stent implantation were found. Conclusions Bioabsorbable iron-based stent planted in the pig pulmonary artery may experience a certain degree of degradation, and it is safe and stabile in animals.