Extension of radiofrequency ablation of the liver by transcatheter arterial embolization with iodized oil and gelatin sponge: results in a pig model.

Purpose: To determine whether transcatheter arterial embolization (TAE) with iodized oil and gelatin sponge particles can be used to expand radiofrequency (RF)-induced coagulation necrosis, the morphology and histologic characteristics of ablation lesions were evaluated in the normal pig liver after three different TAE procedures.

Materials And Methods: Ten consecutive animals with 33 ablation lesions produced with an RF ablation system were randomly assigned to one of three treatment groups and a control group: a group treated with TAE with iodized oil, a group treated with TAE with gelatin sponge, a group treated with TAE with iodized oil and gelatin sponge, and a control group in which TAE was not performed. After the completion of ablation, the lesions were excised for gross and histologic examination.

Results: The longest and shortest diameters of ablation lesions were greatest in the group treated with TAE with iodized oil and gelatin sponge, followed by the groups treated with TAE with gelatin sponge and TAE with iodized oil (P < .05 vs controls, respectively). The hemorrhagic rim was also widest in the group treated with TAE with iodized oil and gelatin sponge (P < .05 vs controls), and it spread toward the liver periphery like a segmental hemorrhagic area adjacent to the ablation lesion. Histochemical staining for lactate dehydrogenase, maleate dehydrogenase, and nicotinamide adenine dinucleotide diaphorase showed what appeared to be 100% cellular destruction in all the ablation lesions and their hemorrhagic rims.

Conclusion: RF ablation combined with TAE with iodized oil and gelatin sponge induces the greatest area of coagulation necrosis accompanied by peripherally spreading segmental necrosis in normal pig liver tissue.