Direction of Tissue Contraction after Microwave Ablation: A Comparative Experimental Study in <i>Ex Vivo</i> Bovine Liver
Junhyok Lee, Hyunchul Rhim, Min Woo Lee, Tae Wook Kang, Kyoung Doo Song, Jeong Kyong Lee
Abstract
OBJECTIVE: bovine liver models. MATERIALS AND METHODS: bovine liver models, including the surface (n = 60) and parenchyma (n = 30), to examine the direction of contraction of the tissue in the peripheral and central regions from the microwave antenna. Three commercially available 2.45-GHz microwave systems (Emprint, Neuwave, and Surblate) were used. For surface ablation, the lengths of two overlapped square markers were measured after 2.5- and 5-minutes ablations (n = 10 ablations for each system for each ablation time). For parenchyma ablation, seven predetermined distances between the markers were measured on the cutting plane after 5- and 10-minutes ablations (n = 5 ablations for each system for each ablation time). The contraction in the radial and longitudinal directions and the sphericity index (SI) of the ablation zones were compared between the three systems using analysis of variance. RESULTS: < 0.001). There was a significant difference in the longitudinal contraction properties, whereas there was no significant difference in the radial contraction properties. CONCLUSION: The degree of longitudinal contraction showed significant differences depending on the microwave ablation equipment, which may affect the SI of the ablation zone.