Asymmetric oscillation of cavitation bubbles in a microvessel and its implications upon mechanisms of clinical vessel injury in shock-wave lithotripsy

A theoretical model for constrained oscillations of a cavitation bubble inside a vessel is developed, and an approximate solution, including the second-order effect when the vessel radius is significantly larger than the bubble, indicates that the effect of asymmetric bubble oscillation due to the vessel constraint is significant even with a very moderate initial wall velocity, and that this effect magnifies itself with time. Neglecting the effect of asymmetric oscillation leads to a substantial underestimate of the peak pressure exerted on the vessel due to the bubble oscillation, underscoring the importance of the asymmetric oscillation on the resulting vessel dilation, which has been viewed as a primary mechanism for the clinical injuries of capillary and small blood vessels in shock wave lithotripsy.