drsclafani wrote: i want an explanation of how a vein that has a 30% stenosis (presumably for years) and has not been dilated by angioplasty can develop a 80% stenosis in six months
I've read here that the parts of the venous systems being used depends on body position, so it seems that what is seen through venous imaging often might depend on body positioning and likely adds variability to what is going to be seen via imaging.do you think might be owed to image variation due to positioning of the subject?
1eye wrote:more so perhaps in the IJVs and other cerebral outflow veins, where posture really makes a difference, than lower down in the azygos?
Cece wrote:hydration status or inconsistencies in measurement....
My reason for asking the question is that there is some variance in reporting 30% and then 80% stenosis. When something is clearly phasic, i wonder when it is justified to treat. Clearly, it is highly unlikely that spontaneous change in the diameter of the vein would be due to increasing stenosis.
So it would depend upon where in the azygous vein this stenosis resided.
As has been stated, variations in position really make a difference. But where? In the arch? or in the ascending azygous vein?
Certainly, as Lyon states, the view performed can make a great difference. We know that angulations of the ray beam of 70-90 degrees from the vertical lays out very nicely the entire azygous arch. Less angulation of the beam could certainly change the view of a stenosis.
1eye considers this less likely than in the jugular vein where position of the neck makes a difference. Rotation of the neck can sometimes eliminate a severe narrowing in the J-2 segment of the IJV.
did you realize that different phases of breathing can really change the narrowing of the Azygous vein in the junction of the upper and middle thirds of the ascending azygous vein..
I happen to be very skeptical of the mid- ascending azygous stenosis. The diameter and the flow in this area is highly dependent upon the phase of respiration. If the images of the vein are taken during deep inspiration, there is usually less narrowing of this junction. During deep expiration it is usually narrow and there is more retrograde contrast flow into the peripheral vessels indicating reflux.
With IVUS one can see the vessel enlarge during inspiration and shrink during expiration. Because of this, I have chosen not to angioplasty this inconstant stenosis.
Can you tell us where in the azygous vein was the stent placed? Was it in the arch? or in the ascending portion?