Blood thinners alone, do not remove the clot but allow time to the body to dissolve the clot.
Unfortunately, this does not occur always and the vein may remain blocked forever. Thrombolytics ("clot busters") can dissolve a clot quickly, over a period of a few hours to a couple of days.
The procedure involves a puncture usually behind the knee with the patient in the prone position. Under x-ray guidance wires and catheters are navigated to the blocked vein.
Depending on how much clot is present and how old the clot is your vascular surgeon will determine which device to use. Some devices allow to administer the "clot-busting" drug directly into the clot.
Other devices break up the clot into tiny pieces that are then removed with suction through the catheter.
Often, these techniques uncover a particular narrowing of the vein (e.g. May-Thurner syndrome) that caused the blood clot to form and this can immediately be treated by implanting a stent to open the vein (venoplasty).
The benefit treating this narrowing, is that it will likely decrease your risk of developing blood clots in the future. Immediate clot removal is also anticipated to reduce the occurrence of the long term complications of DVT, mainly the post-thrombotic syndrome.
Patients with the best outcomes are patients that have had symptoms that are less than 30 days. The clot seems to respond very favorably when it is "fresh".
The optimal outcomes are seen in patients with symptoms less than 14 days. As with any operation, thrombolysis of a DVT has several risks, the major one being bleeding.
You will want to discuss these risks thoroughly with your vascular surgeon.