[In vitro studies of shock wave effects during ablation of normal and atherosclerotic vascular wall by excimer laser].
Ablation of atherosclerotic plaque and normal arterial wall was performed using a xenon-chloride-excimer laser with a wavelength of 308 nm and a pulse duration of 115 ns. The light was transmitted via a 600 micron fiber and adjusted to an energy density of 3.5 J/cm2. The acoustic signals generated by the laser pulse were measured with hydrophones consisting of polyvinylidenefluoride with active diameters of 0.3 mm and recorded on a dual-channel digital storage oscilloscope using either a 0.5 m coaxial cable or a broadband transmission system. From 19 cadavers human aortic tissue segments were excised and macroscopically classified as either normal or calcified atherosclerotic plaque. Approximately 500 measurements were performed in saline and blood each. Histological analysis was carried out after the experiments to verify the macroscopic diagnosis and to correlate the acoustic responses with the tissue characteristics. For "normal" arterial segments, maximum peak pressure was 1.25 MPa +/- 0.85 MPa, rise time 163 ns +/- 43 ns, and pressure increase 8.2 kPa +/- 5.4 kPa/ns in saline. For calcified, atheromatous segments a significantly higher maximum pressure (2.20 MPa +/- 1.16 MPa), a significantly shorter rise time (69.9 ns +/- 25.8 ns), and a significantly higher pressure increase (32.3 kPa +/- 21.3 kPa/ns) was found in saline (p < or = 0.0001). In blood, maximum peak pressure was 1.29 MPa +/- 0.43 MPa, rise time 93.3 ns +/- 27.7 ns, and pressure increase 14.6 kPa +/- 5.2 kPa/ns for "normal" arterial segments. Maximum peak pressure (2.28 MPa +/- 0.63 MPa) and pressure increase (32.8 kPa +/- Pa/ns) were significantly higher for calcified tissue segments.(ABSTRACT TRUNCATED AT 250 WORDS)
Haase
K K
KK
Abteilung für Kardiologie, Universität Tübingen.
Hanke
H
H
Baumbach
A
A
Wehrmann
M
M
Rose
C
C
Karsch
K R
KR
D017222:Angioplasty, Balloon, Laser-Assisted / Q000295:instrumentation*; D001794:Blood Pressure / Q000502:physiology; D003324:Coronary Artery Disease / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D003326:Coronary Circulation / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D009131:Muscle, Smooth, Vascular / Q000473:pathology / Q000503:physiopathology; D017539:Tunica Intima / Q000473:pathology / Q000503:physiopathology
In-vitro-Untersuchungen zu Stosswelleneffekten während der Ablation von normaler und atherosklerotischer Gefässwand durch Excimer-Laser.