The Volume Difference Of Microwave Ablation On Different Organs

ObjectiveExplore the shape and extent of the liver, lung, kidney and muscle with the implantable Water-Cooled microwave ablation in vitro, and compare the size of the ablation volume of four different organs.MethodsThe procedure, ablating the liver, lung, kidney and muscle tissues in vitro with the implantable Water-Cooled microwave antenna, under the conditions of the different ablation power set to 30w, 40w, 50w, 60w, 70w, 80w respectively, and different ablation time set to 2,4 , 6,8,10,12 minutes respectively, which includes the combination of 36 parameters of"power / time", was repeated 3 times. The transverse diameter and longitudinal diameter were measured of the ablation lesions, and calculated the size of the ablation volume.ResultsThe shape of coagulation ablation lesions, having clear boundaries with the surrounding normal tissue, is mostly ellipsoidal or spherical, which can be divided into four grossly visual areas: carbonation zone, coagulation necrosis zone, transition zone and normal tissue zone, corresponding with regional histopathological manifestations. The regression curve fitting analysis of the relationship among the ablation power, time and volume with Statistical Software shows that the size of ablation volume increases with the increasing of the ablation time under the condition of the constant power. But when the time reaches to 8-12min, the ablation volume is stable (p <0.0001), and the same characteristics can be observed with the constant time (P <0.0001). With the same power and same ablation time, the size of ablation volume of the four different organs and tissues, largest in the muscle and smallest in the lung, descends in the order of the muscle, liver, kidney, and lung, which has a significant statistical difference. The comparison between the any two groups were statistically significant (P <0.05). ConclusionThe pig organs and tissues in vitro, mostly ellipsoidal ablation or coagulation of spherical lesions. Fixed ablation power, increasing ablation time, the ablation volume increases; fixed ablation time,increasing the ablation power, ablation volume has increased. Additional power or (and) time, ablation volume of four different organs and tissues are no longer increasing. The size of volume in descending order is muscle> liver> kidney> lung based on the same ablation power and time.