Do surgical clips interfere with radiofrequency thermal ablation?

Area of Science:

• Medical Devices
• Interventional Radiology
• Surgical Oncology

Background:

• Surgical clips are commonly used in liver procedures.
• The impact of surgical clips on radiofrequency ablation (RFA) is not well understood.
• Ensuring safety during RFA in patients with prior clip placement is crucial.

Purpose of the Study:

• To investigate if surgical clips alter tissue conductivity during RFA.
• To determine the safety of performing RFA in the presence of liver surgical clips.
• To evaluate the effect of clip proximity on RFA lesion formation.

Main Methods:

• Ex vivo porcine liver model utilized for experimentation.
• Surgical clips positioned at varying distances (10, 20, 30 mm) from a radiofrequency electrode.
• Standardized RFA application for 5 minutes, with lesion morphology and growth documented.
• Clip orientation (perpendicular or parallel to electrode track) analyzed.

Main Results:

• RFA lesions were generally circular and homogeneous after 5 minutes.
• Early lesion formation showed irregularity, extending towards a 1 cm clip.
• A distinct lesion formed around the 1 cm clip within the second minute.
• The primary lesion eventually incorporated the satellite lesion around the 1 cm clip.
• No lesions were observed around clips positioned 20 mm or further from the electrode.

Conclusions:

• Radiofrequency ablation can be safely performed in patients with implanted surgical clips.
• Aberrant conduction around surgical clips was not observed when clips were 20 mm or further from the RFA electrode.
• Clip proximity significantly influences RFA lesion development, with closer clips potentially creating satellite lesions.