University of Wisconsin–Madison

Noninvasive Liver Ablation Using Focused Ultrasound Histotripsy

July 2016 to June 2017

The purpose of this study is to determine the feasibility of histotripsy (focused ultrasound cavitation) to ablate renal and liver tissue. The study will be performed in several phases. The breakdown of MRI use for each phase follows:

1. Pilot study using Eovist, an MRI contrast agent (2 animals). The purpose of this phase of the study is to determine the appropriate dose and transit time of Eovist in pig livers. In two unaltered animals, we will anesthetize the animal, place them in the MRI scanner, inject them with IV Eovist, and image them repeatedly until Eovist is excreted into the common bile duct. Note that we will use an abbreviated version of the human MRI/MRCP protocol for this study. This pilot study will help determine the best timing of imaging after Eovist administration in future ablated pigs, show the normal pig bile duct anatomy, and help determine technical parameters to use when imaging the bile ducts post ablation.
2. Histotripsy of pig liver (15 animals). The animals will be divided into two groups (central liver ablation versus peripheral liver ablation) and scanned after histotripsy. Attention will be paid to creating an ablation zone surrounding lobar bile ducts. The purpose of this study is to determine if histotripsy is able to ablate peri-ductal tissue without damaging the adjacent bile duct—which would be a unique aspect of histotripsy versus conventional thermal ablation methods.
3. Histotripsy of pig kidney (15 animals). There will be 15 animals divided into a peripheral kidney and central kidney group. The purpose of this part of the study is to determine whether histotripsy spares the renal pelvis and collecting system.

This project led by: Fred T Lee Jr, MD