Fall, 2009
 
This article was chosen because it deals with vessels (the vertebrals) that play a key role in posterior circulation, but aren’t readily researched.  Vertebrals aren’t researched frequently because they are “technically difficult to evaluate with ultrasound (Hurcan et al. 2004 p.1483)”.  In fact vertebral stenosis has received little attention because in addition to being difficult to evaluate, it is  poorly understood (Hurcan et al. 2004 p.1487). There are many advances in surgical procedures, such as stenting, that include the vertebrals.  This has caused research on the vertebrals to become more popular.  Therefore, more research is needed to understand their role in circulation with significant stenosis.
 
The main purpose of this study was to evaluate the diameter, flow velocity, peak systolic velocity, and time average velocity in normal vertebrals (Hurcan et al. 2004 p.1484).  Patients included in the study had 50% or less stenosis at the carotid bifurcation or had 50% or more stenosis without significant collateral flow from the vertebral system.  One hundred and eighty patients were evaluated using color Doppler ultrasound and angiographic techniques.  For consistency purposes the same staff radiologist, protocol, procedures, and machine were used.  Having one technologist do the Color Doppler studies was deemed a major limitation to the study due to the possibility of technique errors.  To lessen the likelihood of mistakes all measurements were taken 3 times and averaged.
 
Sixty of the original 180 patients were eliminated from the study due to various vascular disorders leaving 120 patients for comparison.  The 120 patients included men and women whose ages varied from 40 to 79 years old.
 
The study results showed  out of 120 patients 90 had 50% or greater ICA stenosis, 30 had 50% or less, and 11 had total ICA occlusions with ICA circulation preserved from the anterior communicating circulation. This data was consistent with angiographic results.  There were no significant diameter differencesnoted within the group.  On average the flow volume and diameter of the left vertebral were higher than the right.
 
In conclusion, vertebral evaluation is important when evaluating the perfusion of posterior circulation,  Color Doppler is very important when evaluating flow volume in the vertebrals because vertebral insufficiency is sometimes clinically undetectable and hard to quantify.  This study showed that blood flow in normal vertebral arteries is not affected in some cases even when there is a total occlusion of the ICA without collateral flow (Hurcan et al. 2004 p.1490).  The data in this study correlated well with the angiographic data.  More studies are needed to gather a more significant amount of data.  This increase of data may help develop the new and upcoming technological and surgical advances.

References
Hurcan, Cem, MD, Kizikilic, Osman, MD, & Mihmanli, Ismail, MD, et al. (2004).  Color Doppler Analysis of Vertebral Arteries Correlative Study With Angiographic Data.  The Journal of Ultrasound in Medicine, 23, 1483-1491.