Vascular Bubble Generation for Diagnosis and Therapy

University Of Michigan At Ann Arbor, Ann Arbor MI

Investigators

Linked publications & trials

Abstract

DESCRIPTION (provided by applicant): Developments and large animal trials of vascular embolization by transcutaneous Acoustic Droplet Vaporization (ADV) are proposed. After, intravenous, infusion, superheated droplets at body temperature will be caused to vaporize into microbubbles at the desired location in the body by applying ultrasound through the skin. This will allow rapid, minimally invasive vascular occlusion at targeted sites. It is expected that this treatment will be faster and less expensive and invasive than comparable angiographic techniques for reducing flow or hemorrhage in emergency situations or before thermal, cavitational or surgical interventions and may prove much faster and less expensive and invasive as a complete local treatment than either thermal or surgical intervention. Necessary droplet production and vaporization processes have been studied. The 30- 120 um bubbles from ADV have been shown to have suitable properties for infarction of superficial leporine and canine tissue regions in either the treated volume or identifiable supply vessels. Therapeutic studies in the canine kidney are addressed in definitive tests of in situ ADV. Specifically, it is proposed to transition from previously demonstrated occlusion by bubbles from intra-arterial droplet injections to occlusion by bubbles from intravenous injections of droplet emulsions. After achieving the generation of necessary bubble concentrations from transpulmonary droplets, similar copious quantities will be produced by transcutaneous vaporization of these droplets in non-superficial feeder arteries, e.g., a segmental renal artery and then the entire renal artery prior to branching of the capsular arteries or the capsular arteries themselves. ADV at depth will be achieved by use of a therapeutic array with appropriate beam shape for full arterial embolization and more than adequate focal gain, power and pressure amplitude for deep ADV. Full embolization of renal cortical tissue for the time required for tissue death, or even the time to prepare and perform other procedures such as partial nephrectomy or RF or cryo-ablation, will be an invaluable tool for saving time, as well as complications and mortality in those alternative or subsequent kidney ablation/resection procedures. The venereal sarcoma cancer model will then be employed in the canine kidney to verify the ability of ADV to provide embolization therapy for treating cancer directly, or in combination with RF ablation. The ADV only requires an intravenous injection of droplets and transcutaneous ultrasound. Similar human trials should be ready for implementation in the next renewal.