Blood clots in the lung (pulmonary embolism, PE): interventional radiologists perform 2 different forms of treatment, placement of devices (inferior vena cava filters) to capture blood clots before they reach the lung preventing further PE. When there is a massive PE causing collapse an interventional radiologist may use small catheter tubes to break up the blood clot and restore blood flow.
Dilated veins (varicose veins): these most commonly occur in the legs but can occur in the pelvis or scrotum. These can be treated by blocking the vein by heat treatment (laser or microwave) or by the use of irritant drugs and embolisation techniques.
Your physician will firstly confirm all your weak veins, using a Duplex Ultrasound Scan and will determine the best place to insert the catheter. You will be asked to wear protective glasses because laser is used in this procedure. Your physician will then clean, shave and numb this area with a local anesthetic.
Once the area has become numb, a small incision is made and a catheter and a guide-wire are inserted into your skin. Next, a laser fiber is passed through the catheter until it extends approximately 1 to 2 centimeters from the end, at which point it is secured in place. The laser energy seals the faulty vein and blood flow is re-directed to healthy veins. The entire process takes approximately takes an hour.

Blocked veins: this can occur in the context of blood clot in the veins (venous thrombosis, DVT) which is sometimes treated by the injection of blood clot dissolving medicines (thrombolysis) through a small catheter passed into the vein. Some patients develop blood clots as a result of a narrowing in a vein, when the clot has been broken down using balloons and stents. Sometimes tumours in the chest will compress a vein leading to facial swelling, headache and other symptoms which can usually be relieved with a stent.