球囊扩张成形术治疗胸主动脉狭窄的实验研究

Percutaneous transluminal angioplasty (PTA) of aortic stenosis in chest(an experimental study in dog)

目的 :探讨胸主动脉狭窄时高血压形成的机理 ,寻找有效的治疗方法。材料和方法 :健康杂种家犬10只 ,全麻下 ,手术暴露胸主动脉 ,结扎胸主动脉制成动物模型。股动脉穿刺插管造影 ,观察狭窄前后主动脉直径 ,测量狭窄前后主动脉压力 ,并抽取主动脉血做肾素活性测定。于狭窄后4周 ,再次插管行球囊扩张成形术 ,于扩张前后测量动脉压并抽取主动脉血测血浆肾素活性。扩张后2周再次插管测主动脉压并测血浆肾素活性。结果 :10只犬 ,动脉模型制作成功 ,狭窄处直径均为原直径25 %以下。于狭窄后即刻血压升高(P<0 01) ,狭窄后4周血压进一步升高(P<0 01) ,扩张后即刻血压有下降(P>0 01) ,2周后恢复正常。血浆肾素活性 ,狭窄后4周升高(P<0 01) ,扩张后2周左右恢复正常。结论 :胸主动脉狭窄时 ,血压升高是由于狭窄上方血管容量增加及血浆肾素活性增高共同引起 ;球囊扩张成形术是治疗胸主动脉狭窄的一种简便、安全。

Objective:To explore the mechanism of high blood pressure when stenosis of thoracic aorta exist and look for an effective method to treat aortic stenosis in chest.Materials and methods:In 10 dogs,thoracic aorta was exposed by operation under general anaesthesia and narrowed with chromic catgut.The angiography of aorta was done,the diameter and pressure in aorta were measured before and after narrow,before and after PTA,and 2 weeks after PTA.The blood was drawn from aorta to determine the plasma renin activity.PTA was done 4 weeks after narrow.Result:Animal model was made successfully in 10 dogs,the diameter of thracic aorta was less than 25% diameter before narrow:blood pressure of thoracic aorta rose(P<0 01)immediately after narrow, and rose(P<0 01) again 4 weeks after narrow.The blood pressure of thoracic aorta fell(P<0 01)immediately after PTA but returned to normal 2 weeks after PTA.The plasma renin activity rose 4 weeks after narrow and returned to normal 2 weeks after PTA.Conclusion:The reason of high blood pressure when stenosis of thoracic aorta exist is both increase of blood volume in aorta over narrow and increase of plasma renin.PTA is a simple,effective and safe method to treat stenesis of thoracic aorta.