Noninvasive assessment of pressure gradients across iliac artery stenoses: duplex and catheter correlative study

Abstract

The present study investigates prospectively the validity and accuracy of the simplified Bernoulli equation in the duplex-derived determination of pressure gradients across iliac artery stenoses in patients with occlusive artery disease. In 28 patients (age range, 38 to 76 years; mean, 53 years) with short iliac artery stenoses, we obtained both duplex scan stenotic jet velocity and catheter pressure measurements. Mean and maximum pressure gradients were determined by both methods, as was the peak-to-peak catheter gradient. The correlation between the duplex-determined and nonsimultaneously measured catheter mean pressure gradients was r = 0.77 (standard error of the estimate [SEE] = 5 mm Hg), that between the duplex-derived and catheter-determined maximum pressure gradients was r = 0.80 (SEE = 10 mm Hg), and that between maximum duplex-determined and peak-to-peak catheter gradient was r = 0.76 (SEE = 12 mm Hg). The peak-to-peak catheter gradient was significantly lower than the maximum duplex-derived gradient (46 versus 53 mm Hg, P < 0.05). Duplex-determined mean pressure gradient decreased from 15 +/- 6 to 3 +/- 1 mm Hg after balloon angioplasty of the iliac stenoses. Duplex scan can be used to predict pressure gradients across short iliac artery stenoses, provided that errors caused by angle malcompensation are prevented.

Ambient pressure sensitivity of microbubbles investigated through a parameter study

“…One noninvasive approach that has been suggested is to perform Doppler echocardiography using a simplified modification of the Bernoulli equation. 1,2 This method was, however, concluded not to yield reproducible or reliable results by Strauss et al 3 Another type of approach, which is still being investigated, is to combine microbubbles injected into the blood and diagnostic ultrasound.…”

Modeling subharmonic response from contrast microbubbles as a function of ambient static pressure

“…On the other hand, currently available non-invasive procedure using Doppler ultrasound has been reported to be non-reproducible. 22,23 The idea of using scattering properties of microbubbles for non-invasive pressure estimation has been around for over three decades. 13, 24 Fairbank and Scully 25 first proposed using air bubbles for cardiac pressure measurements.…”

Peripheral arteries

“…Attempts have been made to quantify pressure loss from measured velocities using a modified Bernoulli equation with limited success. 42,43 The use of velocity ratios in multiple stenoses is somewhat controversial. While some reports have suggested that velocity ratios produce lower accuracy in the presence of severe adjacent disease, 44,45 others suggest that criteria are unaffected.…”