You asked for feedback from other vascular technologists regarding
the use of arterial duplex imaging versus physiologic testing. I have
been a vascular technologist for over twelve years, and I am in
complete agreement with Rob Daigle's recent flownet comments on this
issue. I can't argue against the superiority of duplex imaging at
localizing the level of disease and determining stenosis versus occlusion.
But I am a pragmatic person and, in this increasingly cost conscious
health care environment, I think we have to provide the service which
will answer the clinical question and provide quality patient care
without inflating the cost. Therefore, I can't understand having a
"routine" for any series of tests like always doing a duplex study after
an abnormal multilevel physiologic study. It would make sense to have
an algorythm for doing the duplex in certain instances, e.g. the
patient is definitely going on for revascularization and they want to
determine if 1) it is a lesion that could be angioplastied, or 2) the surgeon
operates based on the duplex without a preop angiogram. I am not sure
how essential having preop velocities are for comparison to postop
measurements since I would expect them to change anyway. I would
hope to see them normalize, and I would still be looking for a significant
focal velocity increase as evidence of residual stenosis. The postop
study would be a valuable baseline for future follow-up studies.
I may be missing something since I don't routinely duplex in
addition to PVR's/pressures, but I really can't see how doing it for all
abnormal PVR's is justified. Most of the time, one primary screening
study is needed to document the presence and severity of arterial
disease, and if the patient is a surgical candidate, he or she will go on
to arteriography anyway. We prefer using PVR's/segmental pressures as our
primary testing modality but I understand that some labs use a complete
duplex with an ABI.
This brings me to the length of time for a duplex study. I am
amazed at your skill in performing a complete segmental exam and duplex
from the aorta down in 45-60 minutes. We are a hospital lab. A large
percent of our patients are elderly and very sick, often with diffuse
multilevel disease. I am just curious what your patient population is
like and what impact this might have on length of study.
Finally, I would be reluctant to include aorto-iliac scanning as
a routine part of surveillance because I would have to schedule them to be
NPO before the test for optimum results. This is just not feasible for me
to do as a routine for all patients, because I don't have the staff
or equipment to get everyone done in the morning. In effect, I would
be delaying studies which could have a negative impact on patient
care, patient convenience, or hospital costs. Or I could do
suboptimal studies with inadequate visualization of certain segments.
This brings me back to "Why do both physiologic and duplex as a
Comments are welcome.
Mary Watts, BSN, RN, RVT, RDMS