Noninvasive ankle pressure measurements by oscillometry

Area of Science:

• Vascular Medicine
• Diagnostic Imaging

Background:

• Peripheral vascular disease (PVD) diagnosis relies on accurate noninvasive vascular assessments.
• Ankle pressure measurements are crucial for evaluating PVD severity and guiding treatment.
• Limitations exist in current noninvasive techniques, especially with calcified or incompressible vessels.

Purpose of the Study:

• To compare noninvasive ankle pressure measurements using oscillometry and Doppler ultrasound.
• To evaluate the accuracy of oscillometry in patients with varying degrees of peripheral vascular disease.
• To assess the impact of vessel calcification and differing Doppler pressures on oscillometric readings.

Main Methods:

• Noninvasive ankle systolic, mean, and diastolic pressures were measured using an oscillometric device.
• Systolic pressures were simultaneously measured using Doppler ultrasound at the posterior tibial or dorsal pedal artery.
• Measurements were performed on healthy subjects and patients with mild, moderate, and severe peripheral vascular disease.

Main Results:

• Oscillometry and Doppler showed agreement in normal subjects and limbs.
• In mild PVD, both methods showed decreased systolic pressure with normal mean/diastolic pressures.
• In moderate PVD, oscillometry overestimated systolic pressure compared to Doppler; mean pressure decreased.
• Oscillometry reflected higher Doppler pressures in cases of differing pedal pressures but was lower in incompressible vessels.
• The oscillometric device failed to detect pulses in severe PVD cases.

Conclusions:

• Oscillometry and Doppler are comparable in healthy individuals but show discrepancies in PVD.
• Oscillometry's accuracy is affected by vessel calcification and disease severity, potentially leading to over- or underestimation of systolic ankle pressure.
• The limitations of current oscillometric devices in severe PVD highlight the need for more sensitive instrumentation.