title: Shock-wave thrombus ablation, a new method for noninvasive mechanical thrombolysis.
abstract: Successful experimental and clinical experience with thrombus ablation has been attained with high-power acoustic energy delivered in a catheter. The goal of this study was to investigate the feasibility of noninvasive thrombus ablation by focused high-power acoustic energy. The source for high-power acoustic energy was a shock-wave generator in a water tank equipped with an acoustic lens with a fixed focal point at 22.5 cm. Thrombus was prepared in vitro, weighed (0.24 +/- 0.08 g), and inserted in excised human femoral artery segments. The arterial segments wer ligated, positioned at the focal point and then randomized into either test (n = 8) or control (n = 7). An x-ray system verified the 3-dimensional positioning of the arterial segment at the focal point. A 5 MHz ultrasound imaging system continuously visualized the arterial segment at the focal point before, during and after each experiment. The test segments were exposed to shock waves (1,000 shocks/24 kv). The arterial segment content was then flushed and the residual thrombus weighed. The arterial segment and thrombus were fixed and submitted to histologic examination. The test group achieved a significant ablation of thrombus mass (0.25 +/- 0.15 vs 0.07 +/- 0.003 g; p = 0.0001) after application of shock waves. Arterial segments showed no gross or microscopic damage. Ultrasound imaging revealed a localized (1.9 +/- 0.5 cm2), transient (744 +/- 733 ms), cavitation field at the focal point at the time of application of focused shock waves. Thus, focused high-power acoustic energy can effect noninvasive thrombus ablation without apparent damage to the arterial wall.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Urology, University of Michigan, Ann Arbor.
authors.forename: U
authors.initials: U
authors.lastname: Rosenschein
authors.forename: S J
authors.initials: SJ
authors.lastname: Yakubov
authors.forename: D
authors.initials: D
authors.lastname: Guberinich
authors.forename: D S
authors.initials: DS
authors.lastname: Bach
authors.forename: P L
authors.initials: PL
authors.lastname: Sonda
authors.forename: G D
authors.initials: GD
authors.lastname: Abrams
authors.forename: E J
authors.initials: EJ
authors.lastname: Topol
mesh_terms: D005263:Femoral Artery / Q000473:pathology; D006801:Humans; D007083:Iliac Artery / Q000473:pathology; D066298:In Vitro Techniques; D008096:Lithotripsy; D013927:Thrombosis / Q000473:pathology / Q000628:therapy*