Health & Disease Info
All You Wanted to Know About ... Phlebitis
and Blood Clots
Patient information is designed to help you understand what is
going on when inflammation in the veins and blood clots have occurred,
usually in the leg. In order to help you understand this better
we have tried to compartmentalize this overview so that we consider
the anatomy and functioning of the veins in the normal state and
also in the diseased state. This should help you to understand the
chronic changes that take place and what needs to be done to help
prevent some of the more severe chronic problems.
In this section we are talking about diseases of the veins.
Veins are blood vessels which return blood to the heart after they
pass through the nutrient blood vessels and tissues of the body.
Since man stands in an upright posture, the blood flow through the
veins is usually against the forces of gravity so that a mechanism
is required to prevent the blood from rolling back down the veins
instead of proceeding upwards to the heart.
A mechanism that has been provided takes the form of valves within
the veins and peripheral muscle pumping functions. The valves are
present in just about all veins and are shaped like curved doors
so that blood is allowed to pass through them in the direction going
towards the heart. But if gravity pulls the blood back again, the
doors go closed and the blood is maintained above the level of the
valve. Each time a step is taken or a muscle is contracted, blood
is emptied from the veins within that muscle. The blood is propelled
forward toward the heart through the open valves. When the valves
are healthy and close tightly there is no leakage, and these are
called competent valves. However, when the valves have been damaged
by disease or blood clots or by enlargement of the veins so that
the valves can no longer come together accurately, then leakage
does occur and the valves are said to be incompetent.
There are two main types of veins in the legs. The first are the
ones lying deep within the muscles called the deep veins. These
are involved in the muscle pump action and are responsible for returning
the majority of the blood to the heart. The second type called superficial
veins are merely collecting veins located on the surface just under
the skin and have very little muscular support.
Acute Venous Disease
of the time when we speak of acute venous disease we are talking
about deep vein thrombosis or DVT. This results in blood clots forming
in the veins which either partially or completely block the flow
of the blood through the vein leading to pain from pressure within
the leg and significant swelling. It is felt that there are three
components which contribute to the formation of DVT. One component
is very slow movement of blood through the veins (called stasis).
Another component is an inflammation of the vein wall itself. Finally
there may be an increased tendency for the blood to clot (hypercoagulability).
Anything that changes any of these three parameters can be responsible
for causing DVT. Factors that would contribute to venous stasis
(or slowing the flow of blood) would include pregnancy, inactivity,
surgery, obesity, injury, or varicose veins. A very common cause
of stasis is sitting for a long time with one's legs hanging down.
This is many times done in a long trip in the car or bus or train.
Conditions which usually affect the vein wall are usually direct
injury with trauma to the vein. Many mechanisms can increase the
"clotability" of the blood including hormonal drug therapy,
cancer, blood disorders, or unusual medical problems. DVT can occur
not only in the leg but also in the arm. This is an unusual problem
but does account for up to 5 to 10% of the incidence of phlebitis.
Symptoms usually consist of pressure and swelling of the arm or
leg. There may be enlargement of the superficial veins seen under
the skin. And a dusky, bluish discoloration may occur.
diagnosis of DVT is not as easy as one might think and even with
a thorough history and physical the accuracy of the diagnosis is
only about 50%. Therefore, the presence of DVT has to be documented
usually by use of one of two methods, either duplex examination
A duplex examination is a study whereby ultrasound waves are passed
into the extremity both visualizing the vein and any clot that might
be in it and listening to the flow of blood through the vein with
different testing maneuvers. This is usually our front line test.
If a definitive study can be obtained in our office, usually no
further studies are required. If, however, duplex study can not
be obtained or if the results from a duplex study are questionable,
then venography will have to be done. A venogram is done by placing
a needle into the vein in the foot or wrist with injection of x-ray
dye. X-ray pictures are taken as the dye proceeds toward the heart.
The treatment of DVT is basically medical. When blood clots
are fresh, they are actively forming more clots and are not well
attached to the veins. Our main interest at this point is to stop
all clotting by using medications and to prevent the clots from
moving by maintaining bedrest. The mainstay of treatment is the
use of Heparin. Heparin is a drug which neutralizes all of the active
clotting components in the blood and prevents further clots from
forming. This drug does not actually dissolve blood clots but prevents
new ones from being formed so that the body may resorb clots that
have been formed. A second drug called Coumadin is started concurrently
for the long term treatment of DVT. Coumadin fools the liver into
making some inactive clotting factors instead of active clotting
factors that are usually made from Vitamin K.
In this way with a reduced level of active clotting factors present
in the blood there is a lower chance that new blood clots will be
formed while the body is absorbing the blood clots that are already
present in the veins. Heparin must be continued in the hospital
until the Coumadin has had a chance to exert its maximum effect.
This usually takes about a week, give or take a few days. For the
first five days of treatment you are to remain in bed and move around
as little as possible until the blood clots that are present within
the veins have a chance to attach themselves to the vein walls by
formation of scar tissue. Once the clots are fixed to the vein walls,
then it is safe to get up and move around. Surgical intervention
in deep venous thrombosis is almost never indicated. It is used
in only extreme cases. There are some newer drugs on the market
which are designed to actually dissolve the blood clots that are
present and restore blood flow within the veins. These drugs are
used for immediate short term treatment in the hospital and may
have some advantages over Heparin and Coumadin. However, the advantages
have not been confirmed at this point in time, and they continue
to be used in an investigational manner.
More Information About Coumadin
Most experts feel that patients with deep venous thrombosis
should be treated with Coumadin for a minimum of three months if
clots are present in the smaller veins and up to six months if they
are present in the larger veins. If pulmonary embolism occurs, then
treatment is extended for about one year. Because this is a long
term treatment and because Coumadin can be a dangerous drug information
about this particular drug would be given so that you can understand
the importance of following all instructions.
Coumadin is basically rat poison! It is the same chemical that
the exterminator uses in the garage to kill rats and mice. However,
it is prescribed in a very limited and controlled manner. Your clotting
parameters are monitored very closely by blood work. It is imperative
that you take the Coumadin as directed and also obtain all follow-up
studies that are recommended. Chemically Coumadin looks very much
like Vitamin K. Vitamin K is made in the bowel by the bacteria,
that are resident within the bowel, digesting the portion of the
food that you eat but do not digest. The Vitamin K made by the bacteria
is then absorbed through the wall of the bowel and carried to the
liver. Since Coumadin looks very similar to Vitamin K, the liver
is fooled by this and makes some of the clotting factors with Coumadin
and some clotting factors with Vitamin K. Coumadin based clotting
factors are inactive. Therefore, the total amount of active clotting
factors present in the blood becomes lower and the blood takes longer
to clot. In examining this mechanism it becomes obvious that a number
of factors can affect the effect of Coumadin. This is a dynamic
equilibrium with balance between active and inactive clotting factors.
Therefore, anything that increases or decreases the amount of Vitamin
K presented to the liver with respect to the dose of Coumadin will
change the balance of these two chemically similar substances and
will change the balance of clotting factors and affect the clotting
times. It is therefore recommend that you do not take any vitamin
tablets that are not recommended by your physician since some vitamin
tablets contain Vitamin K.
Another recommendation is that you maintain the same type of diet
and not participate in any "fad diets" or other significant
changes in your dietary habits while taking Coumadin unless you
discuss these first with your physician. If you become sick and
are unable to eat properly or if you develop diarrhea or some other
bowel problem, this may also upset the amount of Vitamin K received
by the liver. You should notify your physician as soon as possible
if something like this occurs. Another way that the body's response
to Coumadin changes is by changing the metabolism of the liver.
There are any number of drugs on the market that will either increase
or decrease the metabolism of the liver causing a significant change
in the anticoagulation effect of Coumadin. Before taking any of
these drugs you should discuss their effects with your physician
so that he will follow your prothrombin time more closely and make
needed adjustments in the Coumadin dosage.
Since Aspirin is a direct irritant of the stomach, it should never
be taken in conjunction with Coumadin since any ulceration caused
by the Aspirin may very well bleed and continue to bleed because
of the effects of Coumadin. Early in treatment we obtain prothrombin
times frequently to establish the proper dose of Coumadin. Once
we are at a steady level we reduce the frequency of these blood
tests and in the long term obtain them about once a month unless
some change in medication or health would otherwise dictate a more
close follow-up. The use of Coumadin is associated with a number
of complications not the least of which are bleeding complications
if the prothrombin time gets out of range. Nonhemorrhagic side effects
are uncommon but include necrosis of the skin (in which dead skin
would become black and then ulceration would occur), dermatitis,
( a rash, weeping of the skin, etc.) and a syndrome of painful redness
and swelling in areas of large amounts of subcutaneous fat. Most
of these changes are reversible if the drug is stopped.
is very important to remember also that Coumadin is teratogenic,
(causes malformed babies) and should never be used during pregnancy
or in a lactating mother. In this particular situation subcutaneous
Heparin is used for long term management of DVT.
Complications of DVT
The acute complications of DVT are basically two; congestion
in the involved extremity, and movement of the blood clot to the
lung, a so called pulmonary embolus. This early fresh blood clot
is dislodged from the vein. It can be carried through the larger
veins and lodge itself in an artery to the lung thereby preventing
blood from going into this area of the lung and being oxygenated.
This condition is life threatening and is usually accompanied by
severe apprehension and shortness of breath with severe chest pain,
sweating, and fainting. The pulses are very rapid and occasionally
bloody sputum is produced.
proper anticoagulation is maintained, this usually does not recur
and the body will be able to clear the clots in the lungs and return
circulation there, however, in the acute phases this is a life threatening
condition and intensive medical care is required. Our entire treatment
protocol for the treatment of DVT is designed to avoid this complication.
The treatment of pulmonary embolus is again mostly medical using
anticoagulants, oxygen, and pain medicines, The thrombolytic drugs
which actually dissolve blood clots are used more in this acute
situation and anticoagulants in the form of Heparin and Coumadin
are continued through the later stages of treatment. Occasionally
surgery is required for removal of the blood clot in emergency situations,
but this is not a standard part of therapy. If anticoagulants can
not be used properly or if recurrence of pulmonary embolus occurs,
there are a number of ways to interrupt the veins so that further
emboli can not proceed to the lungs.
Discussion of Greenfield Filter
most common way of interrupting the venous return to the heart is
by insertion of a "Greenfield filter". This is a basket
of bent wires made of Titanium which is inserted usually percutaneously
(with a direct stick through the skin) into the vein and then a
very small incision to insert the mechanism for delivery of the
filter. Guidewires are placed in the vena cava , (the big vein in
the abdomen returning blood to the heart) and the filter is delivered
over a guidewire to its proper place just below the veins from the
kidneys and then fired to stay in the vena cava.
There are pointed feet in this wire basket which dig into the wall
of the vein and prevents it from moving. The Greenfield filter can
be inserted either through the right groin or through the jugular
vein in the right neck. Occasionally we can not obtain a good "stick"
of the vein percutaneously, and an incision has to be made to identify
the vein for insertion of the filter. However, this is an unusual
circumstance. Once the filter is in place, the insertion apparatus
is withdrawn. There are no symptoms of having the filter in place
and minimal complications occur. One complication that can occur
is swelling of the legs. This would be due to passage of clot up
to the filter and occlusion of the filter with increased venous
pressure in the legs. This is a very unusual complication. It occurs
only when a large thrombus is dislodged from the lower veins. It
simply signifies the fact that a large pulmonary embolus would have
occurred had the filter not been in place. While the swelling of
the legs may be an inconvenience, the result of the embolus without
the filter would have been death. On the average these filters stay
open about 95% of the time so that it is only a very small group
of patients who will ever have symptoms from it.
chronic changes of deep venous thrombosis results in venous stasis
disease also known as chronic venous insufficiency. While varicose
vein formation can develop following deep venous thrombosis, it
is not usually the most significant consideration here. While chronic
venous insufficiency develops over a period of years, efforts to
prevent the complications of chronic venous insufficiency must start
immediately. The blood clots that have formed in the veins will
take six months to a year to be completely absorbed by the body.
While there is obstruction to blood flow there will be swelling
of the limb.
swelling is best controlled using elastic compression in the form
of elastic stockings. These will usually make the leg feel much
less heavy and prevent it from swelling significantly as the clots
are being absorbed. However, even after the clots are absorbed elastic
compression is still the mainstay of treatment of venous stasis
disease. As the clots are being absorbed, the valves within the
veins are also absorbed so that the valvular function is destroyed.
As a result, once the calf muscle pump relaxes, blood also flows
down the leg, and there is a chronic increased pressure within the
veins because of the destroyed valves. As the venous pressure increases,
there is a tendency for fluid to leak out of the blood vessels and
into the tissues causing chronic leg swelling.
This tissue is rich in protein, and while the water portion of
it is reabsorbed, in many cases the protein remains in the tissue
and forms a barrier to diffusion of oxygen to the skin. This causes
the long term sequela of skin breakdown and ulceration if not corrected.
The use of elastic stockings will prevent this swelling and protein
accumulation from developing and will prevent the end stage findings
of chronic venous stasis disease. The standard symptoms of chronic
venous stasis disease include pain when standing, (which is usually
relieved with elevation of the leg), swelling, tenderness, skin
discoloration, dry, scaly, and itchy skin, and ulcers can also form.
Since the symptoms occur primarily in the lower leg below the knee,
it is felt that elastic compression up to the knee joint will have
the optimal effect in preventing these changes.
the end stage changes occur, they are often not reversible so that
the key to treatment is prevention. Following an episode of deep
venous thrombosis the patient should continue using firm elastic
support in a below the knee position for the remainder of his or
her life. In the chronic treatment of venous stasis disease it must
be remembered that the affected tissues will have a tendency to
develop infections much more easily, so that the close observation
for the development of early infection needs to be carried out with
institution of antibiotic therapy early rather than later in this
setting. Also periods of elevation of the legs to significantly
reduce the venous pressures from within will contribute to lowering
the incidence of long term complications.
We hope that this information has helped you to understand
the problem of phlebitis and its sequela and some of the factors
that must be considered in proposing a treatment program. Once phlebitis
has occurred, there is nothing we can do to prevent that particular
problem and the approach is then designed to prevent the long term
sequela of chronic venous insufficiency. If you have further questions,
please bring them to our attention, and we will be happy to discuss
them with you individually.