Toward Large Ablations With Single-Needle High-Frequency Irreversible Electroporation In Vivo.

Area of Science:

• Biomedical Engineering
• Oncology
• Medical Devices

Background:

• Irreversible electroporation (IRE) is a minimally thermal ablation technique for tumors near critical structures.
• Clinical use of IRE is hindered by complex anesthesia and electrode placement challenges.
• High-frequency irreversible electroporation (H-FIRE) with a single-insertion probe shows promise but has limited ablation volumes.

Purpose of the Study:

• To improve H-FIRE waveform design for increased operating voltage and ablation volume using a single-insertion bipolar probe.
• To overcome limitations of current H-FIRE systems, including Joule heating and small ablation sizes.
• To evaluate the feasibility of H-FIRE for generating clinically relevant, minimally thermal ablations.

Main Methods:

• Optimized H-FIRE waveform by adjusting interphase and interpulse delays to increase safe operating voltage before arcing.
• Utilized an actively cooled, single-insertion bipolar probe for H-FIRE delivery.
• Performed in vivo experiments in swine liver to assess ablation volumes and characteristics.

Main Results:

• Improved H-FIRE waveform design enabled higher maximum operating voltages.
• Achieved significant ablation volumes (up to 4.62 cm x 1.83 cm) in swine liver within 5 minutes.
• Ablations were minimally thermal, ultrasound-visible, and induced an immune response without cardiac synchronization.

Conclusions:

• Novel H-FIRE waveform design and probe system can rapidly create clinically relevant, minimally thermal ablations.
• The single-insertion bipolar probe offers a more user-friendly alternative to traditional IRE.
• Optimized H-FIRE shows potential to overcome limitations and expand clinical adoption for tumor ablation.