猪腹主动脉下端狭窄对邻近上游血流动力学的影响

Influence of abdominal aorta extremity stenosis on proximal upstream artery haemodynamics in swines

目的观察腹主动脉下端不同程度狭窄引起的邻近上游管腔血流动力学的改变。方法幼年家猪6只，利用血管夹夹闭腹主动脉下端侧壁依次造成1／4、1／2、3／4管腔狭窄及管腔完全闭合，记录对应邻近腹主动脉血流流速曲线波形，测算收缩期峰值速度（peak systolic velocity，PSV）、舒张期最小血流速度（minimum diastolic velocity，MDV）。分析所有实验数据并进行统计学处理，观察血流参数与狭窄程度的相关性。结果狭窄达到一定程度后舒张期流速曲线消失，狭窄程度进一步加重到一定程度后出现针状波峰及舒张期低平流速曲线波形，完全阻断时则舒张期流速曲线消失。PSV随狭窄程度加重而减低。结论腹主动脉狭窄引起邻近上游管腔收缩期波峰倾向尖锐，出现针状波峰说明下游管腔存在严重狭窄，如果合并舒张期无血流流速曲线显示则说明下游管腔血流完全受阻。

Objective To study the haemodynamics changes in the proximal upstream artery caused by different degrees of abdominal aorta extremity stenosis. Methods The lateral walls of the abdominal aorta extremity were pinched with the vascular clamp to achieve 1/4,1/2 and 3/4 stenosis or occlusion in 6 juvenile susserota domesticas,the velocity tracing of the proximal artery recorded,and the parameters of the peak systolic velocity（PSV） and minimum diastolic velocity（MDV） were obtained and statistically analyzed for their correlation with different degrees of abdominal aorta extremity stenosis. Results The diastolic velocity tracing vanished when stenosis reached a certain degree, the needle ridge and low amplitude diastolic velocity tracing emerged when stenosis to a certain extent,and only the needle ridge was present when the abdominal aorta extremity was completely obstructed. PSV reduced with the aggravation of stenosis. Conclusions The proximal upstream artery systolic ridge caused by abdominal aorta extremity stenosis tends to be acuminate, which indicates serious stenosis of the downstream artery. The systolic needle ridge and the absence of diastolic velocity tracing would suggest a complete obstruction of the blood stream in the downstream lumina.