Experimental Study Of Microwave Ablation On Breast Tissue

Objective:1,To observe the ablation lesions and shapes of 2450MHz implanted internally cooled microwave in vitro and vivo porcine breast.2,The effectiveness and safety is studied in vivo porcine breast.Materials and Methods:(1)vitro experiment:In vitro porcine breast ablation,using 2450MHz implanted internally cooled microwave,20 experimental groups were created base on the ablation power and duration.2450MHz implanted internally cooled microwave antennae were inserted into vitro porcine breast tissues during experiments, and temperature curves of selected spots were simultaneously recorded by iron-constantan couple temperature-measuring system.Ablated lesions were excided along the representable planes after ablation,the longitudinal diameter,transverse diameter and width of the ablation reaction zone were measured.The volume and shape of the ablation lesions were determined using a special computer software base on the photos of the gross section.(2) vivo experiment:In vivo porcine breast ablation,8 experimental groups were created base on the ablation power and duration.24 ultrasound-guided percutaneous breast ablation experiments were done.24 experiments are done in vivo pigs.Experimental pigs were killed after ablation instantly and 10 days later,respectively.Ablated lesions were excided along the representable planes,the shape of mammary and surrounding tissue were observed by eyes.Pathological changes were analyzed.Results:(1) In vitro experiment,the shape of treated area turns out to be drop-shaped with the combination of 20-60 w,3-10 minutes of microwave ablation.The longitudinal diameters were from 1.65±0.058cm to 3.775±0.096cm;The transverse diameters were from 1.075±0.050cm to 2.70±0.000cm;The volumes were from 1.267±0.700ml to 15.067±0.208ml.The circumscription of pathologic changes caused by 2450MHz microwave ablation lesions is all elliptical and radial symmetry about the antenna.The ablation shape can be controlled by changing the times and power magnitudes.(2) In vitro experiment,with the combination of 20-60 w,3-10 minutes of microwave ablation.the longitudinal diameters were from 1.63±0.51cm to 2.53±0.53cm,the transverse diameters were from 1.37±0.53cm to 2.33±0.52cm.Compare with the result of in vitro,we can get the larger ablation scopeand the better equal circles ratio,but the less stabilityConclusions:The apoptosis could be observed under transmission electron microscope.The ablation circumscriptions in mammary in ex vivo swine and in vivo swine with ultrasound-guided percutaneous is steady.The vivo animal experiment have turned out this way is effect and safe.Therefore,this technique will demonstrate potentially applicable in clinical ablation treatments of breast neoplasm.