It is normal for blood clots to form after injury, but if they become dangerous, doctors may inject thrombolytic agents to dissolve the blood clots, according to the Society for Vascular Surgery. Common thrombolytic agents include tissue plasminogen activator and streptokinase.
To perform the procedure, the doctor identifies an appropriate site on the patient's skin where she can access an artery or vein. She cleans the area and applies a local anesthetic before creating a small puncture. The doctor may proceed to inject the thrombolytic agents with a short catheter and allow the drugs to travel to the blood clot through the bloodstream by themselves. Alternatively, she may use a long catheter to guide the clot-dissolving drugs directly to the location of the blood clot, and in some instances, she may also use special devices on the tip of the catheter to help break up the clot, explains the Society for Vascular Surgery.
The doctor monitors the blood clot by consulting an X-ray screen. When the clot is dissolved to the doctor's satisfaction and the patient displays an adequate ability to coagulate blood, the doctor ceases the delivery of the drugs and removes the catheter. The blood clot may take several hours to dissolve, and in severe cases, it can take days, states the Society for Vascular Surgery.