冠状动脉支架术后再狭窄发生机制的血管内超声观察

Mechanism of in-stent restenosis:An intravascular ultrasound observation

目的:应用冠状动脉造影(CAG)及血管内超声(IVUS)研究冠脉内支架术后再狭窄的发生机制.方法:以成功留置冠脉内支架,于6mo后进行复查的92名患者118处病变(其中前降支53处病变、回旋支32处病变、右冠状动脉33处病变)为对象,进行CAG及IVUS检查,以CAG直径狭窄率≥50%为支架内再狭窄.根据冠状动脉造影结果将患者分为支架再狭窄组(39例)和无再狭窄组(79例),通过IVUS观察两组冠脉内支架术后及随访时参考段血管面积、最小支架截面积、最小血管内膜腔截面积、新生内膜面积、支架体积及新生内膜体积.结果:两组支架置入术后即刻及随访时参考段血管面积、最小支架截面积、支架体积无显著性差异(P>0.01),随访时再狭窄组最小血管内膜腔截面积较无再狭窄组明显减小[(2.3±1.1)mm2vs(5.4±1.8)mm2,P<0.01];而新生内膜面积及体积较无再狭窄组明显增大[(4.7±1.5)mm2vs(1.6±0.8)mm2,(121.1±31.9)mm3vs(54.3±11.4)mm3,P<0.01].结论:支架内再狭窄主要以内膜增生为主,而与血管重构及支架弹性回缩无明显关系.

AIM： To investigate the in-stent restenosis process by coronary artery angiography （CAG） and intravascular ultrasound（IVUS）. METHODS： The study consisted of 92 patients with 118 stents（LAD53, LCX32, RCA33）. Follow-up CAG and IVUS were performed 6 months after stent placement. There were 39 stents with and 79 stents without in-stent restenosis by CAG. The reference areas, minimal stent cross-sectional areas （ CSA）, minimal stent luminal CSA, intimal hyperplasia CSA, stent lumen and intimal hyperpla volume were measured by IVUS. RESULTS： Reference areas, minimal stent CSA and stent volume had no significant differences between restenotic and nonrestenotic stents （ P 〉 0.01 ）. Restenotic stents had smaller minimal stentluminalCSA [（2.3±1.1）mm^2 vs （5.4±1.8） mm^2, P〈 0.01 ] than nonrestenotic stents, but had bigger intimal hyperplasia CSA and intimal hyperplasia volume than nonrestenotic stents [（4.7±1.5） mm^2 vs （1.6±0.8） mm^2, （121.1 ±31.9） mm^3 vs （54.3 ± 11.4） mm^3, P 〈0. 01 3. CONCLUSION： Intimal hyperplasia was important in the development of in-stent restenosis. But the vascular remodeling and the degree of stent dilation had no obvious relationship with in-stent restenosis.