Extracorporeal shock waves act by shock wave-gas bubble interaction

Abstract

Previous animal experimental data had su~ested that extracorporeal shock waves acted by the interaction of shock waves witi remnant gas bubbles Iefi horn eavitational activity from previous shocks (1). ht vitro experitnenk had shown that haemolysis frotn shock waves was reduced by >95 0/0by stitic express pressures of ody 10s kPa in the exposure vessel (2). Two additional experiments confiied the interaction. ht the fret, an identical number of 100 shock waves was administered slower than us~ly to red blood cells and minimal excess pressure was applied. h the second, a single strong shock wave or two strong shock waves were applied to red blood cells. ht both haemolysis was determined, The fust experiment revealed a lower haemolysis at the slower application of the shock waves. Application of a sitt~e strong shock wave caused little haemolysis yet appliution of two shock waves caused a 5-fold increase of haemolysis, Static excess pressure abolished the increase. The only interpretation one can thii of is that the fwst shock had caused remnant gas bubbles which acted strongly at the second shock. The term shock-wave gas-bubble interaction is well known horn cavitation physics and should be used more ofien to describe the mechanism of action of extracorporeal shock waves. TRODUCTIONExtracorpord shock waves are single pressure pdses of 35-120 ma peak pressure followd by a tensile wave. They are clinically applied for lithotipsy (1,2). In tissues they can cause hemorrhages as a side effect. Previous animal experiment data had suggestd that tissue damage is generatti by cavitation, more spectilc by the interaction of shock waves with remnant gas bubbles left from cavitation activity from previous shocks (3). Shock waves can dso cause damage to cells in vitro. Hemolysis, red blood cell des~ction, is a simple means to quant@ it. In vitro experiments had shown that haemolysis from shock waves was reduced by >9570 by static express pressures of ody 105kPa in the exposure vessel (4). This was interpreted as evidence for a reduced shock wave -gas bubble interaction by a reduction of the size of the remnant gas bubbles by the excess pressure. Two simple experiments elucidated this further. One applied shock waves more slowly and the other applid just one or two shock waves, SLOW SHOCK WA~APPLICATION During slow wave application, 100 shock waves were applied to red blood cells with the normal speed of one discharge per smond. In another group 100 shock waves were applied with a slower speed of one discharge every five seconds. Red blood cell Iysis was determined photometrically. The result is shown in the figure on the Iefi.

Physical Shock Wave Mediates Membrane Hyperpolarization and Ras Activation for Osteogenesis in Human Bone Marrow Stromal Cells

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The Euler Equations for Multiphase Compressible Flow in Conservation Form

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Inactivation of Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes by underwater shock waves

“…These holes are likely due to the shock wave-generated cavitation and to the mechanical stress produced by the pressure pulse. Delius, Ueberle, and Eisenmenger (1998) and Loske et al (2002) showed that there is synergy between shock waves and cavitation in the inhibitory effect observed after repeated application of ESW on eukaryotic cells and E. coli ATCC 10356, respectively.…”