Good morning all,
(Long question/request for info)
One of our labs has been approached by a physician requesting that we
measure the IVC when acute DVT is encountered, regardless of location in
the lower extremity. This is to prepare for possible IVC filter
placement. At least one reference from the literature given to us
states, "diameter estimation is clinically important in the correct
selection of a filter, because mega cavae (diameter 28 mm or greater)
require a particular filter." (Kaura DR. Value of frontal caval
measurement in the placement of inferior vena cava filters. Can Assoc
Radiol J. 1999; 50:301-305). Generally, the venogram performed during
the filter placement determines size of the IVC, ergo the best filter
size; however, this physician would like to be prepared.
Per protocol, our technologists will exam the iliacs and IVC when
ilio-caval thrombus is suspected (continuous Doppler signals at the
femoral vein) or when thrombus extends above the inguinal crease and the
proximal extent of the thrombus cannot be determined without looking in
the abdomen. As far as I know, we have not been asked to perform
ultrasound guided filter placement in conjunction with the procedure.
With the IVC having "unusual geometry" (transmural pressure usually
exceeded by extrinsic pressure) in most individuals, I am wondering
which is the best position and method for measurement. Additionally,
according to one institution, they measure the IVC "1 cm below the
junction of the lowest renal vein".
My concerns are 1.) is this a common practice in any of your labs, 2.)
is this considered experimental, 3.) is there a certain way measurements
should be taken (i.e., longitudinal, transverse), and 4.) is there a
precedent to bill for this type of procedure?
We are going to start this right away for this physician, without
billing, until we have more information. We have arranged a meeting with
the physician to determine the protocol for this practice (i.e., on
which patients do we do this?) so input would be valuable.
1. Ashley DW, et al. The Accurate Deployment of Vena Cava Filters: A
Comparison of Intravscular Ultrasound and Contrast Venography. Mercer
University School of Medicine.
2. Other Vascular Interventions: Inferior Vena Cava Filters.
(JM, thanks for the references)
To unsubscribe or search other topics on UVM Flownet link to: