建立及评价适于血流储备分数CT成像模拟的小型猪慢性冠状动脉狭窄模型

目的 建立适于血流储备分数CT成像（FFR_CT）模拟研究的小型猪慢性冠状动脉狭窄模型，并评价其可靠性。方法 巴马小型猪16头，开胸于冠状动脉前降支近或中段放置Ameroid缩窄环。建模后第2周进行冠状动脉CTA监测其狭窄程度；末次冠状动脉CTA检查2日内进行冠脉造影验证狭窄程度，并测血流储备分数（FFR）。基于冠状动脉CTA图像建立计算流体力学模型，获得FFR_CT值，并与FFR值进行比较，验证模型可靠性。结果 10头小型猪成功建模，共完成CTA检查24次，图像质量均达到诊断要求。术后第2周，前降支轻微狭窄，术后第3周9头实验猪狭窄>50%，术后第4周其余1头狭窄>50%。冠状动脉CTA示狭窄程度与冠状动脉造影结果一致。FFR_CT值与实测FFR值差异无统计学意义（t=-1.13，P=0.29）。结论 应用Ameroid环置入巴马小型猪冠状动脉左前降支近段或中段，并定期采用CTA监测，可有效建立适用于基于冠状动脉CTA图像无创性血流动力学模拟研究的慢性冠状动脉狭窄模型。

Establishment and assessment of chronic coronary stenosis model for fractional flow reserve derived from coronary CT angiography in Bama miniature pig

Objective To establish chronic coronary stenosis model for fractional flow reserve derived from coronary CT angiography (FFR_CT) in Bama miniature pig, and to evaluate its reliability. Methods Sixteen Bama miniature pigs were used to establish chronic coronary stenosis models through placing Ameroid constrictor into proximal or middle segments of left anterior descending arteries (LAD). In the 2nd week after modeling, the degrees of stenosis were monitored with coronary CTA. Invasive coronary angiography was used to verify stenosis degrees and measure fractional flow reserve (FFR) within 2 days of last coronary CTA examination. Computational fluid dynamics model was constructed and FFR_CT was calculated by the specialized laboratory based on coronary CTA data respectively. Simulated FFR_CT and FFR values were compared to verify this model. Results Models were successfully established in 10 pigs with a total of 24 coronary CT examinations, of which image quality met the diagnostic requirements. All models were with LAD stenosis<25% in the 2nd week after operation. LAD stenosis >50% was found in the 3rd week in 9 pigs, and the other one was found with LAD stenosis >50% in the 4th week. The results of coronary CTA corresponded to those of coronary angiography. There was no significant difference between simulated FFR_CT and FFR value (t=-1.13, P=0.29). Conclusion Through placing Ameroid constrictor into LAD of Bama miniature pig and monitoring the degree of stenosis with coronary CTA, model of chronic coronary stenosis could be successfully established, which are suitable for noninvasive simulating hemodynamics study based on coronary CTA.