Evaluation of the Influence of Body Position on the Inferior Vena Cava (IVC) Diameter

Age Range:18 - Any
Start Date:October 2010
End Date:November 2016
Contact:Ranjith Vellody, M.D.

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To determine if laying down or standing up changes the diameter of the inferior vena cava.

Patients are referred for IVC(inferior vena cava)filter placement secondary to trauma,
surgery, a fractured pelvis or known blood clots in the lower extremities. The filter is
placed to prevent blood clots from traveling into the lungs. The filters are placed during a
interventional radiology procedure. During the procedure the diameter of the IVC(inferior
vena cava)is measured with the patient in a horizontal position (laying down). The blood
pressure in the IVC when a patient is in this position is relatively low in normal
circumstances, but may increase substantially when the patient is vertical with secondary
dilation of the IVC(inferior vena cava).

Migration of IVC(inferior vena cava)filters is not frequent; however it is a serious
complication, which may be caused by changes in the diameter of the IVC(inferior vena
cava)related to changes in the position of the body and/or increased pressure in the

The purpose of this study is to evaluate how much postural changes of the body affect the
diameter of the IVC(inferior vena cava).

For research purposes patients will have an intravascular ultrasound (IVUS) performed to
measure the IVC diameter before and after a Valsalva maneuver (having the subject hold their
breath and bear down as if they were having a bowel movement). The angiographic table will
be elevated and the measurements will be repeated.

Inclusion Criteria:

1. 18 years of age and older

2. Subjects who will have a clinically indicated IVC filter placement procedure

3. Only subjects with no contraindications to being elevated up to a standing or near
standing position on the angiography table.

Exclusion Criteria:

1. Pregnant

2. Have a broken leg or any other physical condition that won't allow you to stand.

3. If you are in a traction device

4. If you have a brain injury and require special monitoring of the pressure in the

5. Patients on a ventilator cannot participate in this study.
We found this trial at
Ann Arbor, Michigan 48109
Ann Arbor, MI
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