Evaluation Of Hemodynamic Changes Of Proximal Arterial Occlusion In Lower Extremities By Spectrum Doppler Ultrasonography

Objective:Lower arterial occlusive disease refers to a group of lesionsstenosis or even occlusion of extremity arteries below the iliacartery caused by a variety of factors.These diseases can lead to distallimb ischemia or necrosis, seriously affect the patient’s quality oflife. A method of high sensitivity, simple, easily operated is vitalfor clinic. For a long time, arterial X-ray digital subtractionangiography (DSA) has been known as the gold standard for peripheralarterial occlusive disease diagnosis, but the DSA have thedisadvantages of invasive and expensive，which limit its clinicalapplication. With the development of color Doppler ultrasound, colorDoppler diagnosis for lower extremity arterial disease has becomemainstream. In this study, we analysis the changes of DopplerUltrasonography Spectrum in arterial occlusion of lower extremities，and discuss the value of color Doppler in the diagnosis of lowerextremity arterial occlusive disease.Method:There are34patients diagnosis of lower extremity arterial occlusivedisease in this study，including39arteries.We observe and record theitems with two-dimensional ultrasound，including artery running, wall echo,thickness and degree of smooth wall lumen for emboli, thrombus and plaque, thrombus echo characteristics, form segmental emboli activities,embolization, plaque location, size, number, morphology, etc，measure thethickness of artery wall, the size of the outer diameter within the lumen, thelength of the lumen occlusion segments；check the conditions of blood flowin arteries and collateral arteries around， using the Color Doppler.Spectrum doppler ultrasound to observe spectrum and blood flowparameters of the proximal segment about2cm above the block, such asPSV,AT,AC,DT,DC,ST,DRV etc. Make the control group,measure thespectrum of flow parameters of segment about2cm under bifurcation.Applicate statistical analysis software SPSS11.5, compare the twogroups using t-test, P <0.05,that difference is statistically significant.Result:1.Two-dimensional ultrasound shows: location and length of the occludedartery, the wall thickening irregular,sclerosis plaques on the wall, caviyfilled with substantive echo, no boundary with wall. The wall of pulsatiledecreases in the proximal occlusion segment,and the closer to theocclusion segment the pulsatile weakens.2. Color doppler image display:The color become fade at the proximalocclusion segment.When the proximal occlusion segment is smooth,thecolor blood flow break off suddenly at the block segment,and appear asmall bunch of reverse blood flow signal. When proximal l occlusionsegment present "wedge", color blood flow become thin gradually till end. 3. Spectrum doppler display: block segment have no spectrum display.Spectum form unusualat, diastole reverse flow velocity slow or disappear,even apparent diastolic forward flow. First phase wave is up a steep, downgently and pause in the descending limb, which appeared earlier thandiastolic early disappearance of backward wave.4. The differences of PSV、AT、DT、AC、DC、DRV、AT/ST、DT/ST in theproximal occlusion segment compared with control group were statisticallysignificant（P<0.05）。Conclusion:1. Artery occlusion segment can cause hemodynamic changes in theproximal occlusion segment. Color and spectral doppler can evaluatehemodynamic changes.2. Characteristic spectrum shape change can evaluate hemodynamicchanges in the proximal occlusion segment. The differences of PSV、AT、DT、AC、DC、DRV、AT/ST、DT/ST in the proximal occlusion segment compared withcontrol group were statistically significant.3. Spectrum Doppler is more sensitive than color blood flow signal,and canmake up the shortage of in the diagnosing of lower extremity arterialocclusion disease by color doppler flow imaging.4. When arterial spectrum characteristic appear abnormal,first to consider thedistal artery severe stenosis or occlusion.