Treatment of critical limb ischemia using ultrasound-enhanced thrombolysis (PARES Trial): final results.

PURPOSE: To evaluate the safety and performance of ultrasound-enhanced thrombolysis in the treatment of acute thrombotic or embolic occlusion of the lower limb arteries.

METHODS

From April 2005 to July 2006, 25 patients (15 men; mean age 64.1 years, range 37-82) presenting with acute (<14 days old) occlusions of the lower limb arteries were treated with local thrombolysis [recombinant tissue plasminogen activator (rtPA)] in a dosage of 1.0 mg/h using the EKOS Lysus Peripheral Catheter System with an ultrasound core. No bolus injection of rtPA was given. The mean occlusion length was 25.1 cm (range 2-70).

RESULTS

The technical success rate was 100%. Total clot removal was achieved in 22 (88%) patients after 16.9 hours (range 5-24) using a mean 17 mg (range 5-25) of rtPA. In 8 cases, total clot removal of the main lesion was achieved after 6 hours (6 mg of rtPA). In 1 patient, lysis was stopped after 2.5 hours because of bleeding due a dislocation of the introducer sheath. In 2 cases, total clot removal could not be achieved; these patients were successfully treated with thromboaspiration. At the 1-month follow-up, the treated vessel was still patent in 20 patients. Two reocclusions occurred; 1 was treated with a bypass graft and the other with conservative therapy. There were no cases of amputation or death during follow-up. There were no side effects related to rtPA or the catheter system.

CONCLUSION

This study demonstrates that local lysis of acute arterial occlusions using the Lysus Peripheral Catheter System is safe and effective. Blood flow is restored quickly.