Learning objectives
To demonstrate the collateral circulation pathways that can be observed in pathological studies at color Doppler in territories of carotid and vertebral arteries.
Background
The arterial system is responsible for the transport of oxygenated blood to organs and tissues.
Some pathological conditions can interrupt or reduce the blood supply,
for breach of continuity of this system.
We can enumerate the trauma,
the arteritis and atherosclerosis.
Atherosclerosis,
in particular,
can lead to progressive reduction of the volume of blood to an organ,
and is associated with widely known and proven risk factors,
such as hypertension,
obesity,
diabetes,
hypercholesterolemia,
sedentary lifestyle,
chronic kidney disease,
smoking,
among others.
The body has defense...
Findings and procedure details
The reversal of blood flow can be observed at color and spectral Doppler,
which is a hemodynamically significant signal of stenosis or occlusion in proximal arterial bed.
The arterial refilling occurs by collateral circulation,
and the antegrade flow to distal bed,
since the arrival of collateral artery and retrograde flow to proximal segments from collateral artery.
The degree of stenosis of the carotid and vertebral arteries is directly estimated based on color Doppler measurements of flow velocities in the vascular lumen.
However,
the signal which...
Conclusion
The knowledge of the main cranial collateral circulation pathways can assist the understanding and recognition of stenoses,
occlusions and flow compensation pathways in patients with atherosclerosis and arteritis processes.
References
1- Symptomatic Carotid Artery Occlusion: Flow Territories of Major Brain-Feeding Arteries. Peter Jan van Laar,
Jeroen Hendrikse,
Catharina J.
M.
Klijn,
L.
Jaap Kappelle,
Matthias J.
P. van Osch,
Jeroen van der Grond
Radiology,
2007,
Vol.242: 526-534,
10.1148/radiol.2422060179
2- Doppler Sonography of the Intertransverse Segment of the Vertebral Artery.
Carlos N,
MD,
Rosa G,
MD,
Angel C,
MD,
Fernando V,
MD,
Núria B́,
MD,
Concepció B,
MD.
J Ultrasound Med 19:47–53,
2000.
3- Vertebral Artery Occlusion in Duplex Color-Coded Ultrasonography
Kozue Saito,
MD; Kazumi Kimura,...