G.-M. von Reutern 1, I. Alpsoy 2, J. Allendörfer 2
1 Neurologische Praxis am Kardiologischen Zentrum – Bad Nauheim,
2 Asklepios Neurologische Klinik Bad Salzhausen – Nidda, Germany
Objective: Poststenotic peak systolic velocities (PSV) of < 50 cm/s of the distal internal carotid A. (ICA) were introduced as one of the main criteria to differentiate 70% vs 80% stenosis (NASCET definition) (NSRG consensus Stroke. 2012;43:916-921). There is only a sparse evidence for this threshold. Therefore we examined the PSV in patients with risk factors and arteriosclerosis (<50%). With reduced velocities the diameter of the ICA is reducing, a possible additional parameter for grading a stenosis.
Material and Methods: 100 consecutive patients (mean age 65,4 y, range 40-93, male 52%) were examined (GE Logic 7). PSV was measured as distal as possible, at least 2 cm distal to the origin. Due to the variable anatomy the exact distance was not prescribed. The distal diameter of the ICA was measured in systole, if possible with B-Mode, or B-flow imaging for its good spatial resolution.
Results: ICA PSV on the left (right) side was 64,1 (62,7) cm/s, range from 34 to 114 (40-118) cm/s, SD 13,3 (11,9) cm/s, Mean side to side difference was 11% (range 0-59%), 95% of values were.
Discussion: ≥ 50 cm/s PSV of the distal ICA is a valuable threshold to classify ICA without hemodynamic relevant lesions. In this group the diameter can be expected to be ≥ 3,7 mm. The next step in validating these criteria will be to perform the same measurements in patients with high degree stenosis. Beside the absolute threshold side to side differences of PSV, pulsatility and diameter will be of interest.
Key words: grading carotid stenosis, internal carotid artery, velocity.