Shock-induced collapse of a bubble inside a deformable vessel

Abstract

Shockwave lithotripsy repeatedly focuses shockwaves on kidney stones to induce their fracture, partially through cavitation erosion. A typical side effect of the procedure is hemorrhage, which is potentially the result of the growth and collapse of bubbles inside blood vessels. To identify the mechanisms by which shock-induced collapse could lead to the onset of injury, we study an idealized problem involving a preexisting bubble in a deformable vessel. We utilize a high-order accurate, shock- and interface-capturing, finite-volume scheme and simulate the three-dimensional shock-induced collapse of an air bubble immersed in a cylindrical water column which is embedded in a gelatin/water mixture. The mixture is a soft tissue simulant, 10% gelatin by weight, and is modeled by the stiffened gas equation of state. The bubble dynamics of this model configuration are characterized by the collapse of the bubble and its subsequent jetting in the direction of the propagation of the shockwave. The vessel wall, which is defined by the material interface between the water and gelatin/water mixture, is invaginated by the collapse and distended by the impact of the jet. The present results show that the highest measured pressures and deformations occur when the volumetric confinement of the bubble is strongest, the bubble is nearest the vessel wall and/or the angle of incidence of the shockwave reduces the distance between the jet tip and the nearest vessel surface. For a particular case considered, the 40 MPa shockwave utilized in this study to collapse the bubble generated a vessel wall pressure of almost 450 MPa and produced both an invagination and distention of nearly 50% of the initial vessel radius on a 𝒪(10) ns timescale. These results are indicative of the significant potential of shock-induced collapse to contribute to the injury of blood vessels in shockwave lithotripsy.

Spiral computed tomography evaluation of rabbit VX2 hepatic tumors treated with 20 kHz ultrasound and microbubbles

“…When MBs collapse, they can create shockwaves, increasing the local pressure by 100 atm and the local temperature by several thousands of degrees (41). Shockwaves can cause substantial cell damage and possible cell lysis nearby (42). The destruction of MBs may cause high-energy microstreams or microjets that will result in shear stress on the membrane of an endothelial cell and increase its permeability (43).…”

Low-frequency ultrasound-mediated microvessel disruption combined with docetaxel to treat prostate carcinoma xenografts in nude mice: A novel type of chemoembolization

“…Different studies have shown that microbubbles could induce significant bioeffects on confining vasculature (15)(16)(17). The bioeffects range from increasing the vascular permeability for the chemotherapy drug and target gene delivery by opening the blood-brain barrier locally and transiently, to vessel rupture and occlusion (11,12,(18)(19)(20)(21)(22)(23).…”

Numerical simulation of the aerobreakup of a water droplet

“…The numerical method, which is both shock and interface capturing, is based on the work on Johnsen & Colonius (2006). Since its development, MFC has been used to study non-spherical bubble collapse (Johnsen 2007;Johnsen & Colonius 2009) and shock-induced collapse of bubbles inside deformable vessels (Coralic & Colonius 2013). Verification of the algorithm via benchmark test cases and parallel performance metrics have previously been documented (Coralic & Colonius 2014;Coralic 2015;Meng 2016), and are not reproduced here.…”