A new hope for patients suffering from pulmonary embolism is going to emerge through a recent technique, ultrasound-accelerated catheter-directed thrombolysis, that combines the heat and energy of ultrasound with highly targeted delivery of clot-busting drugs. The new technique proved to be an effective treatment for patients with acute massive pulmonary embolism (PE), known as blood clot in the lung.
The innovative technique is created by EKOS Corporation, Bothell, Washington. It adds a new dimension to catheter-directed thrombolysis (CDT), a procedure in which a high concentration of clot busting medication is delivered directly to the embolus over an extended period of time through an infusion catheter. In ultrasound-accelerated CDT, the infusion catheter includes an element device that emits ultrasound energy in the therapeutic zone; the ultrasound works to allow the thrombolytic agent to penetrate the clot, thus reducing both the length of time of the infusion and the volume of thrombolytic drug used.
Ultrasound-accelerated CDT provides excellent results for PE patients.
A 46 patients study conducted over ten years showed that treatment of massive PE by ultrasound-accelerated CDT achieved complete thrombolysis in 100 % of the patients compared to 67 % patients receiving CDT without ultrasound, according to Peter Lin, M.D., professor of surgery at the Baylor College of Medicine at the VEITHsymposium. Both the average dose of thrombolytic agent and the length of time for infusion were lower for patients receiving ultrasound-accelerated CDT. Moreover, there were no hemorrhagic complications within this group compared to 3 incidents in the CDT group. All patients receiving ultrasound-accelerated CDT were treated with tissue plasminogen activator (tPA) as the thrombolytic agent. tPA was administered in 16 of the 21 patients undergoing CDT, with urokinase as the thrombolytic for the other five.
Dr. Lin said: "while both CDT and ultrasound-accelerated therapy have remarkable therapeutic effects for this life threatening condition, the EKOS device provides a significant added benefit of clearing most if not all the clot while using less drug." PE causes over 300,000 deaths every year in the United States, and most of these are the result of acute massive PE and typically occur within one hour of presentation. For patients with hemodynamic instability from massive PE, systemic thrombolysis is considered to be the first line of treatment. Dr. Lin added: "In institutions with appropriate clinical expertise. Ultrasound-accelerated thrombolytic is a beneficial treatment option in patients who have acute massive PE with contraindications to systemic thrombolysis, when time to administer systemic thrombolytic agents is lacking, or when no improvement follows stand intravenous thrombolytic administration."