"It depends on what your definition of is, is."  Bill Clinton,
     President of the United States.

     "The carotid bulb is defined as the dilated (bulbous) first portion of
     the internal carotid artery just as it leaves the bifurcation.  This
     is to be distinguished from the carotid sinus, ie, the terminal
     enlarged portion of the common carotid artery, which gives rise to the
     bifurcation of the internal and external carotid arteries."

        Wesley Moore, HJM Barnettt, Hugh Beebe, Eugene Bernstein, Bruce
        Brener, Thomas Brott, Louis Caplan, Arthur Day, Jerry Goldstone,
        Robert Hobson II, Richard Kempczinski, David Matchar, Marc Mayberg,
        Andrew Nicolaides, John Norris, John Ricotta, James Robertson,
        Robert Rutherford, David Thomas, James Toole, Hugh Trout III,
        Davi Wiebers. "Guidelines for Carotid Endarterectomy:  A
        Multidisciplinary Consensus Statement From the Ad Hoc Committee,
        American Heart Association." AMA Medical/Scientfic Statement,
        Special Report.  American Heart Association, Inc, 1995.

     "Doppler Velocity Prediction of Common Carotid Artery Stenosis," will
     be presented at the 22nd Annual Conference, SVT, September, 1999.

______________________________ Reply Separator
Subject: Re: Grading percent stenosis.
Author:  "" [SMTP:[log in to unmask]] at PHS
Date:    5/6/99 8:12 AM

At this time all published criteria are based upon the first 3 cm of the
ICA.  I am not aware of any published criteria for bulb and cca.  However,
if the bulb stenosis extends up to the ICA with the highest velocities in/or

just at the proximal the ICA then the standard criteria's can be used.  If
the bulb stenosis is more proximal and the highest velocities are not at the

origin of the ICA, then the criteria's cannot be used with reliability.  At
Cedars Sinai and at Ochsner Clinic, we used the following rational with
fairly good correlation results.  Due to the increased diameter of the CCA
and Bulb as well as the combination ICA/ECA flow dynamics we would overcall
stenosis by ~ 10 - 20% and reconcile this call based upon visual findings.
Likewise for stenosis of the vertebral artery similar rational was used.
Due to the decreased diameter of the vert's, althought generally their flow
characteristics are the same as those in the ICA, we would undercall by ~
10 - 20% and reconcile this call based upon visual findings.
Keep in mind that in 70% of cases the left vertebral is dominant and that
the right may be hypoplastic with a more high resistant flow signal.  Does
anyone else have any non-published or know of any published criteria for the

CCA or bulb.  I have seen some published criteria for vertebrals, one from
extracranial work and two from intracranial work.

Cathy Mankin, LPN, RVT