A Comparative Study of Ablation Boundary Sharpness After Percutaneous Radiofrequency, Cryo-, Microwave, and Irreversible Electroporation Ablation in Normal Swine Liver and Kidneys

Abstract

Purpose To compare ablation boundary sharpness after percutaneous radiofrequency (RFA), cryo (CA), microwave ablation (MWA) and irreversible electroporation (IRE) ablation in normal swine liver and kidney. Material and Methods Percutaneous CT-guided RFA (n=5), CA (n=5), MWA (n=5) and IRE (n=5) were performed in the liver and kidney of 4 Yorkshire pigs. Parameters were chosen to produce ablations 2–3cm in diameter with a single ablation probe. Contrast-enhanced CT imaging was performed 24 hours after ablation and animals were sacrificed. Treated organs were removed and processed for histologic analysis with hematoxylin and eosin, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Three readers independently analyzed CT, H&E and TUNEL stained images of the ablation boundary to delineate regions of 1) viable cells, 2) complete necrosis, or 3) mixture of viable and necrotic cells which was defined as the transition zone (TZ). The width of TZ was compared across the techniques and organs. Results Ablations appeared as non-contrast-enhancing regions on CT with sharp transition to enhancing normal tissue. On TUNEL stained slides, the mean width (μm) of the TZ after MWA was 319 ± 157 in liver and 267 ± 95 in kidney, which was significantly lower than RFA (811 ± 477 and 938 ± 429); CA (452 ± 222 and 700 ± 563); and IRE (1319 ± 682 and 1570 ± 962) (all p<0.01). No significant differences were observed between the organs. Conclusion Under similar conditions, the width of the TZ at the ablation boundary varies significantly between different ablation techniques.

How large is the periablational zone after radiofrequency and microwave ablation? Computer-based comparative study of two currently used clinical devices

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Combined radiofrequency ablation and ethanol injection versus repeat hepatectomy for elderly patients with recurrent hepatocellular carcinoma after initial hepatic surgery

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Physiological and Histopathological Effects of Electroporation Pulse on Stomach of Rats

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