Many patients with acute deep venous thrombosis also have an iliac (pelvic) vein stenosis (narrowing). Thrombolyis uncovers this stenosis, which can then be corrected in order to keep the vein open and to avoid repeated episodes of deep venous thrombosis. The stenosis is corrected by placing a balloon catheter in the narrowed vein segment and inflating the balloon, thus performing a balloon angioplasty. If this is not entirely successful, a stent (a slender, metallic mesh cylinder) is placed within the narrowed segment of the vein and dilated. The stent keeps the vein open and prevents it from collapsing.

The complication of greatest concern is bleeding. Most commonly this occurs from the puncture site of the catheter. Other areas of the body, such as the gastrointestinal tract, genitourinary system, or musculoskeletal areas that might have been traumatized are potential sources of bleeding. The most feared bleeding complication is intracranial (within the brain), which is rare in patients without risk factors for this complication. Pulmonary embolism is also a rare complication of thrombolysis.