Benefits and risks

Information for the public

When NICE looked at the evidence, it decided that there was not enough evidence to know how well this procedure works. The 9 studies that NICE looked at involved a total of 272 patients.

Generally, the studies showed the following benefits after the procedure compared with catheter‑directed thrombolysis without ultrasound:

complete or partial clearance of blood clots in most patients
reduced treatment time
improvements in heart function
improvements in blood pressure in the pulmonary artery
most people (19 out of 22) with the most serious types of pulmonary embolism were still alive 180 days after treatment.

The studies showed that the risks of the procedure were:

One person had acute kidney failure and their heart stopped beating; this person later recovered.
In 7 people there was a lot of bleeding; 5 of these needed a blood transfusion. There was a small amount of bleeding in 21 people.
Within 3 months of the procedure 7 people died; these deaths were mainly in people with severe pulmonary embolism who also had other serious illnesses.

If you want to know more about the studies, see the guidance. Ask your health professional to explain anything you don't understand.