Changes in Doppler waveforms can predict pressure reduction across internal carotid artery stenoses.

Area of Science:

• Neurology
• Vascular Surgery
• Medical Imaging

Background:

• Cerebral ischemia, caused by embolism or hemodynamic failure, poses significant risks.
• Internal carotid artery (ICA) stenosis can lead to reduced cerebral perfusion pressure.
• Accurate assessment of hemodynamic compromise is crucial for patient management.

Purpose of the Study:

• To determine if Doppler waveforms distal to internal carotid artery (ICA) stenosis can predict hemodynamic compromise.
• To evaluate the correlation between Doppler waveform parameters and the degree of stenosis.
• To assess the accuracy of Doppler ultrasound in predicting reduced cerebral perfusion pressure.

Main Methods:

• Consecutive examination of 49 patients with ultrasound Doppler prior to carotid endarterectomy.
• Analysis of pulsatility index (PI), pulse rise-time (RT), and systolic width (SW).
• Correlation of waveform parameters with angiographic degree of stenosis and ICA/CCA pressure ratio determined during surgery.

Main Results:

• All three Doppler waveform parameters (PI, RT, SW) significantly correlated with the ICA/CCA pressure ratio (p < 0.001).
• A 20% reduction in ICA pressure was predicted with 90-95% accuracy.
• Correlation with arteriography was less convincing, with only PI reaching statistical significance.

Conclusions:

• Distal ICA Doppler waveforms accurately predict the degree of hemodynamic compromise in carotid stenosis.
• Ultrasound Doppler is a valuable, simple adjunct for routine evaluation of carotid stenoses.
• This method aids in assessing reduced cerebral perfusion pressure non-invasively.