Blood clots that form inside veins can damage venous valves and cause chronic obstruction. This can lead to chronic high blood pressure inside the vein, resulting in swelling, inadequately oxygenated tissue and skin ulcerations. Returning the blood flow to an obstructed venous segment is referred to as recanalisation.
How does the procedure work?
Venous recanalisation involves delivering drugs to the area to break up the blood clots, preserving the vein valve function.
The interventional radiologist will insert a sheath (a long plastic tube 2-3 mm in diameter) into a vessel in your neck or groin, and will then guide the sheath under imaging to the obstructed vein. The interventional radiologist will deliver specific drugs used to dissolve clots (called fibrinolytic substances) into the clot via a catheter (a thin tube).
You may also need to undergo anti-coagulation therapy and a procedure called a thrombectomy in order for the treatment to be successful. This may include receiving regular imaging tests over the following 24-48 hours.
Why perform it?
The permanent obstruction of the vessel into an extremity or into an organ leads to various acute symptoms. These include pain, a weak or non-existent pulse, paleness, paraesthesia (‘pins and needles’) and paralysis. In the long term, it can cause permanent complications such as tissue necrosis (the premature death of cells).
You will also need to receive treatment for the underlying condition that caused the clot.
What are the risks?
Minor risks include bruising at the puncture site or in the affected area. Major risks triggered by the mechanical manipulation of the obstructed vessel include a deeper blockage of the clot or injury to the vessel wall. In rare cases, the procedure may cause bleeding within the skull, in which case the treatment must be stopped immediately.
1. Results of a prospective randomized trial evaluating surgery versus thrombolysis for ischemia of the lower extremity. The STILE trial. Annals of Surgery. 1994; 220(3):251-66; discussion 66-8. Epub 1994/09/01.