Microwave Ablation: The Differences Between Biliary Cirrhosis and Normal Porcine Liver Using a Cooled-tip Electrode

Area of Science:

• Hepatobiliary surgery
• Minimally invasive therapies
• Radiofrequency and Microwave Ablation

Background:

• Liver cirrhosis presents unique challenges for thermal ablation therapies.
• Understanding the impact of liver fibrosis on ablation efficacy is crucial for treatment planning.

Purpose of the Study:

• To compare in vivo and ex vivo microwave ablation (MWA) outcomes in a porcine model of biliary cirrhosis.
• To investigate the influence of liver cirrhosis on MWA lesion size and characteristics using a cooled-tip electrode.

Main Methods:

• Microwave ablation (MWA) using a cooled-tip electrode was performed under laparotomy in both normal and cirrhotic porcine livers.
• Morphological and pathological features of the ablated zones were assessed and compared between in vivo and ex vivo settings, as well as between cirrhotic and normal liver tissues.

Main Results:

• In cirrhotic livers, in vivo ablated areas were significantly smaller than ex vivo ablated areas (short axis, long axis, and volume).
• Both in vivo and ex vivo ablated areas in normal pig livers were larger than their counterparts in cirrhotic livers, across all measured dimensions.
• This indicates that cirrhotic liver tissue is less responsive to MWA compared to normal liver tissue.

Conclusions:

• Microwave ablation (MWA) lesion volumes are reduced in biliary cirrhotic porcine livers compared to normal livers, irrespective of in vivo or ex vivo application.
• Achieving a comparable ablated volume in cirrhotic liver requires significantly longer ablation durations or higher power settings than in normal liver.
• These findings highlight the need for adjusted MWA protocols when treating cirrhotic liver parenchyma.