325 - Pneumo and Hydro-Dissection of Critical Structures During PEF: A Translational Application of a Bench Experiment

Wednesday, April 15, 2026

11:15 AM - 11:24 AM ET

Presenting Author(s)

Mohammed Elkholy, MD

Postdoctoral research fellow
The Laboratory for Minimally Invasive Tumor Therapies, Department of Radiology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, Massachusetts, United States of America, United States

Author/Co-author(s)

AN

Alex Newbury, MD

Radiologist
Beth Israel Deaconess Medical Center, United States
KA

Katarina Anderson, MD

Radiologist
Beth Israel Deaconess Medical Center, United States
YA

Yossof Abouelnagah, MD

Post-doctoral Research Fellow
Beth Israel Deaconess Medical Center / Harvard Medical School, United States
SA

Salma A. S. A. S. Abosabie

MD/MSc Candidate
Julius-Maximilians-Universität Würzburg, Germany
AM

Ahmad Maaly, MD

Postdoctoral Research Fellow
Beth Israel Deaconess Medical Center/Harvard Medical School, United States
MF

Mohamed Farghaly, MD

Postdoctoral research fellow
The Laboratory for Minimally Invasive Tumor Therapies, Department of Radiology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, Massachusetts, United States of America., United States
Marwan H. Moussa, MD

Vascular and Interventional Radiologist
Beth Israel Deaconess Medical Center, United States

Purpose: To evaluate various separators that could be used with Pulsed Electric Field (PEF) ablation in order to minimize non-targeted ablation and improve patient safety.

Materials and Methods: A two-phase translational study was performed to improve the safety of Pulsed Electric Field (PEF) ablation. The first phase used an agar model to test the electrical insulating properties of various separators, including COz, dextrose (D5), and normal saline (NS), with and without contrast. A PEF probe and sensor were used to measure the resulting voltage and current for each separator. In the second phase, the experiment assessed how electrical conductivity changed as the length of the separating barrier was incrementally increased. The findings were then applied clinically, where CO, was used to create a safe space between a recurrent liposarcoma and the nearby colon and femoral plexus, allowing for a successful PEF ablation.

Results: In the translational experiment, CO2 demonstrated superior isolation properties with no conductivity between the electrode and the sensor in comparison to all other separators; D5W, D5W+contrast, NS, NS+contrast (0.0±0.0, 2.12±0.0, 2.12±0.0, 2.82±0.27 and 3±0.06 KV) and (0.0±0.0, 9±0.84, 8.4±0.0, 14.73±0.09 and 14.73±0.09 A). In phase 2, upon increasing the separator length; 2.16 vs. 4.33 vs. 6.49", the current decreased (12.2, 10.8, and 9.6 A), V1 and V2 increased (2.3, 2.56, and 2.68 KV), and (860, 700, and 680 KV).

A 41-year-old man with recurrent retroperitoneal liposarcoma abutting the femoral plexus and ascending colon underwent PEF treatment with NS hydrodissection. However, the procedure was terminated due to a drop in motor evoked potentials (MEPs) of the right femoral nerve and proximity to the colon. Following bench validation, the patient underwent a repeat PEF ablation using intermittent CO2 for pneumodissection of the adjacent structures. A total of overlapping 19 ablations were performed in the caudal and middle portion of the lesion without a decrease in MEPs. Follow up MRI demonstrated an interval decrease in enhancement and diffusion restriction noted at the inferior margin of the treatment site within the right psoas muscle and expected treatment cavity.

Conclusion: Pneumodissection is an effective, safe separator when using PEF ablation in proximity to vital structures.