Arterial thrombosis and embolism

Just as in the coronary arteries, blood clots can develop at other atherosclerotic sites.  They can rapidly block a vessel (thrombosis) or break into fragments and block branches of vessels farther downstream ( embolism).  This results in a sudden cessation of blood flow to the areas supplied by the artery and branches.  With a sudden blockage, there is no time for collateral arteries to develop.  The body can't compensate for this blood flow reduction.

After learning this, I wanted to know what can cause clotting in an unbroken blood vessel.  I learned that the endothelial surfaces of a blood vessel may be roughened as a result of atherosclerosis. Atherosclerosis is the accumulation of fatty substances on arterial walls.  This condition can induce the adhesion of platelets.  Clots may also form in blood vessels when blood flows too slowly, allowing clotting factors to accumulate in high enough concentrations to initiate a clot.

Clotting in an unbroken blood vessel is called thrombosis.  The clot itself is called a thrombus.  If it remains intact, the thrombus may become dislodged and be swept away in the blood.  This can lead to an embolism.  An embolus is a blood clot, bubble of air, fat from a broken bone, or even a piece of debris transported in the bloodstream.  An embolus that breaks away from an arterial wall may lodge in a smaller diameter artery downstream. If it blocks blood flow to the brain, kidney, or heart, the embolism can cause a stroke, kidney failure or even a heart attack.

I work as a Medical Assistant for family medicine.  Just recently, I had to set up a patient for a CT scan to rule out whether or not the patient had a pulmonary embolism.  His symptoms were shortness of breath and coughing that did not go away after various treatments. He also had an elevated D-Dimer level.  Luckily, the test was negative.  After taking care of this patient, and learning about clots and embolisms in class, I wanted to learn more about medications and treatments that can be used in case I know someone who does have one.

Through research, I learned that thrombolytic medication that dissolves the clot may be given through a catheter directly to the affected area.  If you've had arterial thrombosis or embolism or are at risk of their development, you'll receive blood thinners (anticoagulants) to reduce the likelihood of blood clotting and future problems.  I also learned that there are surgical treatments available.  A surgeon can remove a clot in an artery by making a small opening upstream from the blockage and passing a balloon-tipped catheter past the blood clot.  Once the balloon is downstream from the blood clot, the doctor inflates it and pulls the catheter back to the opening in the artery.  The balloon pulls the blood clot upstream where it can be removed.  Occasionally, it's necessary to replace or bypass the blocked vessel.

I found this very interesting.  I have many patients at my office who are on coumadin which is a type of anticoagulant.  It is nice to know that there are also some surgical options to help remove a clot once it has been formed and then to have medications to take afterwards to help prevent this from happening again.