Correlation between the Degree of Left Subclavian Artery Stenosis and the Left Vertebral Artery Waveform by Pulse Doppler Ultrasonography

Abstract

Background:Development of retrograde blood flow may be observed in the vertebral artery and is associated with progressive ipsilateral proximal subclavian or innominate artery stenosis. The subclavian steal phenomenon is more prevalent in the left subclavian artery (LSA). The purpose of this study was to analyze the correlation between the degree of LSA stenosis and pulse Doppler waveforms of the left vertebral artery (LVA). Methods:A retrospective analysis of LVA waveforms was performed in 22 cases with LSA proximal stenosis before the origin of the LVA in conventional angiograms. The degree of LSA stenosis was classified into 5 groups (<50, 50–59, 60–69, 70–89, 90–100%). Pulse Doppler waveforms of the LVA were also classified into 5 subtypes depending on the depth of the mid-systolic notch representing retrograde blood flow (normal, mid-systolic notch, retrograde flow smaller than antegrade flow, retrograde flow larger than antegrade flow, retrograde flow without antegrade flow). Results:A statistically significant correlation (R² = 0.646, p < 0.0001) was found between the degree of LSA stenosis and the LVA waveform. Conclusions:The pattern analysis of LVA pulse Doppler waveforms seems to be useful in determining the degree of LSA stenosis.

Waveform Patterns and Peak Reversed Velocity in Vertebral Arteries Predict Severe Subclavian Artery Stenosis and Occlusion

“…However, in this study, 92% of patients with severe SA stenosis had type IV or V waveforms. Results from the present study also revealed that all of the patients with SA occlusion had type IV and V waveforms, which is not consistent with a previous report (Sakima et al 2011). In the present study, type IV waveforms represented 70%-89% left SA stenosis, but type V waveforms indicated SA occlusion.…”

“…The present study reconfirmed that the degree of proximal SA stenosis is correlated with the ipsilateral VA waveform (Kliewer et al 2000;Sakima et al 2011;Von Reutern and Pourcelotl 1978). However, compared with the previous report, our study had five VA waveform patterns, was not limited to an evaluation of left SA stenosis, and had a relatively larger sample size.…”

“…The spectral Doppler waveform of the VA has also proven useful for predicting the degree of ipsilateral SA stenosis and determining if blood flow is antegrade or retrograde (Buckenham and Wright 2004;Kaneko et al 1998;Kliewer et al 2000;Sakima et al 2011). In previous studies, VA peak reversed velocity (PRV) has been used to determine the cause of reversed flow (Chen et al 2013(Chen et al , 2014.…”

Subclavian Steal Syndrome

“…3 Usually, hemodynamically significant (50%-60% or higher) stenosis of the proximal SA leads to the development of SSS. 4,5 Depending on the severity of SA stenosis, there are different variants of abnormal Doppler waveforms in the affected VA ( Figure 9). 4,6 Occult subclavian steal (the affected side's VA Doppler waveforms demonstrate antegrade flow with mid-systolic notch-the "bunny sign") corresponds to the milder form of hemodynamically significant SA stenosis, partial subclavian steal (alternating "to-and-fro" waveforms) corresponds to the moderate form, and complete steal (retrograde flow in the VA) is observed in severe cases.…”

Vertebral and internal mammary artery steal syndrome in patients with hemodialysis access

“…VA waveforms were classifi ed in fi ve subtypes as described elsewhere [13]. Type I: normal antegrade waveform …”