Effects of lithotripter fields on development of chick embryos

Effects and Mechanisms

“…Acoustic cavitation in water near the focus of a lithotripter has been reported [106,107], presumably brought about through the negative tail of the pulse. It is generally assumed in ESWL that cavitation plays some part in stone fragmentation [108] and bioeffects [106,[109][110][111][112][113][114][115][116][117]. 15 Williams et al [118] attempted to use the resonant bubble detector described in section 5.1.1(c) to detect shock-induced cavitation bubbles downstream from the exposure site of a Dornier System lithotripter.…”

“…In 1990, Hartman et al [116] stated that "Overall, up to the present time, there is no clear evidence that ultrasound influences the development of the vertebrate embryo/fetus unless there is an associated, biologically significant temperature rise [636,637]." However, they noted that in lithotripsy the patient is subjected to pressures an order or so greater than previously, and demonstrate that though the timeaveraged intensities are so small as to have insignificant bulk heating effect, the exposures can drastically effect embryo development with as few as three double shocks of amplitude 10 MPa.…”

“…In a typical clinical lithotripsy procedure, more than 1000 shocks with pressure amplitudes in excess of 20 MPa are deployed [116]. Temporal peak pressures have been reported as high as 100-300 MPa [639], in contrast to diagnostic ultrasonics, where the largest peaks are no more than about 10 MPa.…”

“…Possible side effects of lithotripsy include, for example, canine lung [109] and kidney [112,113,644] haemorrhage. Workers have researched the effect of lithotriptic exposure on the development of chick embyros [116], effects in canine [113,640] and piglet livers [114], and canine gall bladders [113,640]. Lithotriptic effects on the electrophysiological parameters across abdominal frog skin [645], where exposure to a single shock caused a reversible increase in the total ionic conductance and a decrease in the short circuit current, were similar to those found in a 1-MHz therapeutic ultrasound field [304], as discussed in section 5.2.4.…”

“…In tissue, Kuwahara et al [646] and Delius et al [114] showed that lithotripsy can generate bubbles in tissues that are large enough to be detected by ultrasonic pulse-echo equipment. Hartman et al [116] subjected chick embryos at 72-h incubation to three double shock waves generated by the 9 French probe of a Wolf electrohydraulic lithotripter (Model 2137.50), the fields of which have been characterised by Campbell et al [647]. A significant increase in early deaths, delayed deaths and malformations was seen at pressures of 10 MPa, with possible effects at lower pressures.…”