Venogram
(Venography,
Phlebography, Lower Limb Venography)
What
is a venogram?
A venogram
is a procedure that provides x-ray visualization
of the veins, particularly in the lower extremities
(legs). A special dye is injected that is visible
upon x-ray. The contrast dye allows the physician
to evaluate the size and condition of the veins.
A venogram is one of the more accurate tests used
for diagnosing deep vein thrombosis (DVT), but
can also be used to diagnose other abnormalities.
Depending
on the reason for the procedure, several methods
can be used to examine the veins with venography:
- ascending venography
- identifies the presence and
location of DVT.
- descending venography
- assesses the function of the deep vein valves.
- venography of the
upper extremities - assesses blockage, lesions,
or thrombosis in the veins of the neck and axillary
(armpit) region.
- venacavography - evaluates
the inferior vena cava, the vein that brings
bloods to the heart, for obstruction and malformation.
What
is an x-ray?
X-rays
use invisible electromagnetic energy beams to
produce images of internal tissues, bones, and
organs on film. X-rays are made by using external
radiation to produce images of the body, its organs,
and other internal structures for diagnostic purposes.
X-rays pass through body structures onto specially-treated
plates (similar to camera film) and a "negative"
type picture is made (the more solid a structure
is, the whiter it appears on the film).
Other
related procedures that may be used to diagnose
problems of the veins include vascular studies
and renal venogram. Please see these procedures
for additional information.
A venogram
is used to confirm a diagnosis of DVT and to distinguish
clot formation from other venous obstructions.
It can also be used to evaluate congenital (present
at birth) venous malformations or to locate a
vein for arterial bypass graft surgery. It may
be used to determine the cause of swelling or
pain in the extremity and also to determine the
source of pulmonary emboli (blood clots that have
traveled to the lung).
The
amount of radiation used during a venogram is
considered minimal; therefore, the risk for radiation
exposure is very low.
If you
are pregnant or suspect that you may be pregnant,
you
should notify your physician. Radiation exposure
during pregnancy may lead to birth defects.
Because
contrast dye is used, there is a risk for allergic
reaction to the dye. Patients who are allergic
to or sensitive to medications, contrast dye,
iodine, or shellfish should notify their physician.
Patients
with kidney failure or other kidney problems should
notify their physician. In some cases, the contrast
dye can cause kidney failure, especially if the
person is taking Glucophage (a diabetic medication).
Notify
your physician if you have a history of bleeding
disorders or if you are taking any anticoagulant
(blood-thinning) medications, aspirin, or other
medications that affect blood clotting.
For
certain individuals, a venogram may be contraindicated.
These include persons with a known allergy to
contrast dye, severe congestive heart failure,
and severe pulmonary hypertension.
There
may be other risks depending on your specific
medical condition. Be sure to discuss any concerns
with your physician prior to the procedure.
Certain
factors or conditions may interfere with the accuracy
of a venogram. These factors include, but are
not limited to, the following:
- ability of the patient
to remain still during the procedure
- extreme obesity
- severe swelling in
the legs
- Your physician will
explain the procedure to you and offer you the
opportunity to ask any questions that you might
have about the procedure.
- You will be asked to
sign a consent form that gives your permission
to do the test. Read the form carefully and
ask questions if something is not clear.
- Notify your physician
if you have ever had a reaction to any contrast
dye, or if you are allergic to iodine or shellfish.
- Notify your physician
if you are sensitive to or are allergic to any
medications, latex, tape, and anesthetic agents
(local and general).
- You may be asked to
stop eating and/or drinking for at least four
hours before the procedure.
- Notify your physician
if you are pregnant or suspect you may be pregnant.
- Notify your physician
of all medications (prescribed and over-the-counter)
and herbal supplements that you are taking.
- Notify your physician
if you have a history of bleeding disorders
or if you are taking any anticoagulant (blood-thinning)
medications, aspirin, or other medications that
affect blood clotting. It may be necessary for
you to stop these medications prior to the procedure.
- If a sedative is given
before or during the procedure, you may need
to have someone drive you home afterwards.
- Based upon your medical
condition, your physician may request other
specific preparation.
A venogram
may be performed on an outpatient basis or as
part of your stay in a hospital. Procedures may
vary depending on your condition and your physician's
practices.
Generally,
the venogram follows this process:
- You will be asked to
remove your jewelry or other objects that interfere
with the procedure.
- You will be asked to
remove clothing and be given a gown to wear.
- A pen may be used to
mark various sites of pulses on the leg before
the procedure. This will allow easier monitoring
of the pulses after the procedure.
- You will lie on your
back on the x-ray table.
- After cleansing the
area, an intravenous (IV) line will be inserted
into a vein in your foot.
- An injection of contrast
dye will be given. You may feel some effects
when the dye is injected into the IV line. These
effects include a flushing sensation, a brief
headache, or nausea and/or vomiting. These effects
usually last for a few moments. Also, let the
physician know if you are having difficulty
breathing, itching of the skin, or hives.
- X-rays will be taken
at timed intervals as the dye travels through
the lower extremities.
- A tourniquet may be
placed on the extremity to control the speed
of blood flow.
- The intravenous site
will be flushed with heparin/saline solution,
and the needle will be removed from the vein.
- A pressure dressing
will be placed over the puncture site.
Following
the procedure, your vital signs (heart rate, breathing
rate, and blood pressure) will be monitored frequently
and then at intervals determined by your physician.
The peripheral pulses in your feet, as well as
the temperature, color, and sensation in your
legs will be checked. The injection site will
also be monitored for redness, warmth, swelling,
and tenderness.
Normal
activities and diet can be resumed after the procedure
as directed by your physician.
Drink
plenty of fluids to prevent dehydration and to
help pass the contrast dye.
Notify
your physician to report any of the following:
- fever or chills
- increased pain, redness,
swelling, or bleeding or other drainage from
the injection site
Your
physician may give you additional or alternate
instructions after the procedure, depending on
your particular situation.
The
content provided here is for informational purposes
only, and was not designed to diagnose or treat
a health problem or disease, or replace the professional
medical advice you receive from your physician.
Please consult your physician with any questions
or concerns you may have regarding your condition.
This
page contains links to other Web sites with information
about this procedure and related health conditions.
We hope you find these sites helpful, but please
remember we do not control or endorse the information
presented on these Web sites, nor do these sites
endorse the information contained here.
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