BACKGROUND AND OBJECTIVES: Perfluorocarbon exposed sonicated dextrose albumin (PESDA) microbubbles has been suggested to facilitate thrombus disruption under the transcutaneous ultrasound (US). Thus, we investigated whether such a noninvasive approach could augment thrombolytic effect of fibrinolytic agent in an experimental thrombotic model. MATERIALS AND METHODS: Thrombus formation was induced with electrical injury in the rabbit iliofemoral arteries (n=20): Thrombus occlusion was documented by angiography in all arteries. In the control group, only tissue plasminogen activator (t-PA, 3 mg/kg) was administered intrav-enously in five rabbits. In the Group 1 (n=9), injured arteries were exposed to transcutaneous US (20 kHz, 30 W/cm2, continuous mode) with t-PA (3 mg/kg). In the Group 2 (n=6), the same treatment was given while administering PESDA continuously (10 ml/min, intravenous). Angiographic results were evaluated at 10 minute interval for 1 hour respectively. RESULTS: In the control group, two of five iliofemoral arteries (40.0%) were recanalized and one of nine iliofemoral arteries (11.1%) was recanalized in Group 1. In contrast, four of six iliofemoral arteries (66.7%) were recanalized angiographically in Group 2 (p=0.392 vs. control group: p=0.047 vs. Group 1). However, late reocclusion occurred in all iliofemoral arteries of Group 2. CONCLUSION: Although PESDA with transcutaneous US significantly enhanced initial angiographic patency rate of t-PA, it was associated with high rate of reocclusion. Further studies will be necessary for clinical application of this noninvasive method in acute arterial occlusion.