Does histotripsy of central liver tumors cause biliary ductal injuries? A study in a live porcine survival model and early human clinical experience

Tuesday, April 1, 2025

3:18 PM – 3:27 PM CT

Location: Music City Center, 208 AB

Presenting Author(s)

Allison Couillard, MD

Resident
University of Wisconsin Hospitals and Clinics, United States

Author/Co-author(s)

Paul F. Laeseke, MD, PhD

Assistant Professor
University of Wisconsin, United States
Erica M. Knavel Koepsel, MD (she/her/hers)

Associate Professor
University of Wisconsin, United States
Timothy J. Ziemlewicz, MD

Professor of Radiology
University of Wisconsin Hospital and Clinics, United States
JS

John F. Swietlik, MD

Assistant Professor
University of Wisconsin, United States
LH

Louis Hinshaw, MD

Professor
University of Wisconsin School of Medicine and Public Health, United States
FL

Fred T. Lee, Jr., MD

Professor
University Of Wisconsin, United States

Purpose: Histotripsy is a non-invasive focused ultrasound technique recently FDA-approved to treat liver tumors. Two important characteristics of histotripsy are a high degree of precision and tissue selectively, specifically the preservation of collagenous structures such as bile ducts. The purpose of this study is to evaluate for biliary complications after histotripsy of the central liver in both porcine models and human clinical patients.

Materials and Methods:

Retrospective review of porcine subjects (mean wt=50 kg, n=18) treated with histotripsy in the central liver (treatment zone < 1.0 cm from a lobar bile duct or common bile duct) that survived at least 30 days and had CT or MRI follow-up. Images were assessed for the presence of biliary complications such as ductal dilatation, biloma, or bile leak immediately post-treatment and with 30-day (+/- 5 day) CT or MRI follow-up. For human clinical patients, retrospective review of centrally treated liver lesions treated at a single institution was performed (n=3). Size of the treatment zone, distance from common bile duct, and evidence of biliary complications were evaluated.

Results:

Porcine model: The mean size of the treatment zone immediately post treatment was 3.2 x 3.3 x 1.9 cm (mean prescribed size=2.5 x 2.5 x 2.0 cm, p > 0.05). The mean distance from the central common bile duct was 8.0 +/- 2.0 mm. There was evidence of mild biliary dilatation in two animals (11%) at one month follow-up imaging. No subjects demonstrated evidence of severe bile duct dilatation, bilomas, biliary leaks, hepatic abscesses or gallbladder injuries.

Human clinical subjects: A total of three human subjects met study criteria. The mean age was 57 years, with 1 female and 2 males treated. The lesions treated were hepatocellular carcinoma, melanoma metastases, and colorectal metastases. The mean treatment zone size was 3.2 x 2.8. 3.5 cm and was located 3.0 mm +/- 2.0 mm, from the common bile duct. The mean total bilirubin pre-procedure was 0.7 mg/dL and post-procedure was 0.5 mg/dL (p=0.18). At one month follow-up, there was no evidence of biliary complications seen on imaging or with laboratory findings.

Conclusion:

Histotripsy of the liver adjacent to the central bile ducts does not appear to cause significant biliary complications, even when the target is in direct contact with a central bile duct. This is likely related to the preservation of collagen-based structures identified in prior ex-vivo studies.