Diagnosis claudication: discussion

PAD or not?

True, there is evidence of PAD in both the right and left lower extremities. This is based on an ankle-brachial index measurement < 0.90. The ABI is determined using the higher of the ankle pressures relative to the higher of the brachial artery pressures to determine the ABI.

Level of stenosis?

To determine the level of stenosis, we compare the pressure measurement from one level to the next. A drop in pressure of 20 mm Hg or greater between consecutive segments signifies a significant stenosis between those two levels.

If the upper thigh pressure is already lower than the arm pressure, the stenosis is above the upper thigh (either in the iliofemoral vessels or, if seen bilaterally, this could signify stenosis in the distal aorta or in both iliofemoral vessels).

In this case, there is evidence of stenosis in the iliofemoral vessels on the right and in the superficial femoral artery on the left.

Pulse volume recordings

Pulse volume recording tracing illustrations (credit: http://www.hearthealthywomen.org/tests-diagnosis/peripheral-vascular-disease/pulse-volume-recording.html)

The PVRs can be helpful in addition to the ABI to determine the location of stenosis and severity. A normal waveform will have a brisk upstroke and may have a normal notching of  the downslope. With increasing severity of PAD, the upstroke will be slower and the notching will disappear. PVRs can be particularly helpful when the ABI cannot be interpreted as with non-compressible vessels.

In this case, the waveforms in the upper thighs are mildly abnormal will increasing severity lower in the leg.

The waveform at the ankle has the classic ‘parvus et tardus’ waveform (Latin for ‘small and slow’), indicating a low amplitude and blunted upstroke.

 

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