房间隔缺损封堵术后内皮化不全的实验研究

Experimental study of incomplete endothelialization after atrial septal defect closure

目的:探讨封堵器大小与内皮化不全的相关性。方法:选择成年健康杂种犬18只,以自制房间隔打孔器建立统一大小(直径6 mm)的房间隔缺损(ASD)模型。将其随机分为A、B和C 3组,每组6只(n=6),分别植入8mm、12 mm和16 mm大小的封堵器,于术后3月及6月观察封堵器的形态和内皮化状况。结果:18只犬均成功建立ASD模型,超声测量缺损的大小为(6.0±0.2)mm。A组的封堵器伞盘形态扁平,厚度为(10.0±0.3)mm,B组的封堵器伞盘呈"贝壳状",厚度为(15.4±1.7)mm,明显大于A组(P<0.05)。C组的封堵器伞盘呈"哑铃状",厚度为(24.3±2.5)mm,显著大于前2组(P<0.05)。A组封堵器术后3个月内膜就基本完全覆盖;B组封堵器术后3月内膜覆盖不完整,伞盘表面内膜呈"岛状"覆盖,术后6个月膜覆盖进一步增加;C组封堵器伞盘术后3月绝大部分金属网裸露,术后6个月虽有增加,但仍大部分无内膜覆盖。结论:过大的封堵器可导致ASD封堵治疗后内皮化不全。

AIM： To explore the relationship between the size of the occluder and the incomplete endothelialization after atrial septal defect（ASD） closure.METHODS： Equal-sized atrial septal defect models were established by homemade atrial septal perforators in 18 adult and healthy canines.Canines were then divided randomly into three groups with six canines in each group.Eight-mm occluders with diameter 2 mm larger than the ASD were implanted in group A,12-mm occluders with diameter 6 mm larger than the ASD were implanted in group B,and 16-mm occluders with diameter 10 mm larger than the ASD were implanted in group C.After 3 months and 6 months,morphological changes of the occluders and endothelialization were observed.RESULTS： ASD models were successfully established in all 18 canines and the average ASD diameter was（6.0±0.2） mm measured by TTE.Morphology of the occluders was flat in group A and the average thickness was（10.0±0.3） mm.In group B the morphology was conchoid and the average thickness was（15.4±1.7） mm,significantly thicker than in group A（P〈0.05）.The morphology of the occluders was dumbbell-shaped in group C with an average thickness of（24.3±2.5） mm,significantly thicker than in group B and group A（P〈0.05;P〈0.01）.Three months after operation,the intima in group A was almost completely covered.Incomplete intimal coverage was observed in group B and the intima was ＂island-like＂ 3 months after operation,and the coverage area increased 6 months after operation.In group C,most of the occluders were exposed at 3 months as well as 6 months after operation.CONCLUSION： Oversized occluders in transcatheter therapy of atrial septal defects may result in incomplete endothelialization.