or the iliac vein where, if they embolise,
could be fatal.
Again, the consequences of venous thromboembolism
are clear. There can be fatality if the pulmonary
circulation is markedly occluded. This can
happen suddenly. There can be acute mortality.
There can be recurrence. So the patient may
have an episode of pulmonary embolism. He’s
sick, gets better, goes home from the hospital.
Once they’ve had one episode, they’re
at high risk for another episode. And often
that’s because they develop recurrent thrombophlebitis.
They have a tendency to develop this inflammatory
clotting disorder in the veins and then, of
course, for pieces of it to break off.
Sometimes the veins get completely occluded
with the clot and then they can cause something
I will talk about later called post-thrombotic
syndrome in which the patient experiences
chronic swelling of the leg. And even ulcers
and really a very, very unpleasant sequence
of events can occur with a lot of clotting
in the venous system.
The definition of thrombophlebitis is of course
the presence of thrombus in a vein. It’s
almost always accompanied by an inflammatory
process in the vein wall. As I’ve said before,
it can affect superficial veins when it’s
usually not very serious and often as a result
of some minor trauma. And it can be treated
with just some local heat and maybe some aspirin
or ibuprofen. When it gets in the deep veins,
that’s when there’s a much greater potential
for pulmonary embolism. As we said, pulmonary
embolism can be fatal. And there are a whole
variety of risk factors for developing thrombophlebitis:
long periods of bed rest, long airplane trips,
cancer, heart failure, severe lung disease…
A lot of these place patients at higher risk
for developing thrombophlebitis and pulmonary
I mentioned before the post-thrombotic syndrome.
This is a very serious complication of venous
thrombosis. It’s a long-term complication
of deep venous thrombosis. What happens is
you occlude enough of the veins in the lower
leg so that it is difficult for blood arriving
in the muscles and skin of the leg to get
out of the leg. So you have pooling of blood
there, you have increased pressure from standing,
from gravity. This results in much more fluid
getting out of the capillaries that can be
resorbed. So you have swelling. And then with
all of this swelling, it actually impairs
arterial flow from getting into the tissues
and you may have necrosis – or death of
tissues – and development of an ulcer as
you can see from the picture here.
A number of symptoms are related to the post-thrombotic
syndrome: there can be pain or heaviness in
the leg; itching or tingling; as I’ve already
mentioned, edema swelling; development of
severe varicose veins; brownish or reddish
skin discoloration from red blood cells being
deposited in the skin. And, of course, the
worst complication is ulcers. And even, occasionally,
the ulcer gets infected and this could lead
to amputation. So the post-thrombotic syndrome
can be very, very severe.