Feasibility And Safety Of Flexible Bronchoscopy-guided Microwave Ablation In Peripheral Porcine Lung

PurposeTransbronchial lung biopsy is an important diagnosis of peripheral lung cancer,while an effective treatment under transbronchial lung is absent.A flexible bronchoscopy-guided microwave ablation(MWA)antenna was devised and to be evaluated the feasibility and safety both in ex vivo and in vivo porcine models.The correlation between the ablation parameter was also investigate in peripheral porcine lung.MethodsIn this animal's experimental study,a new flexible bronchoscope-guided microwave ablation needle was used for research and analysis.(1)By antenna penetrated through the surface of ex vivo porcine liver,ablations(n=21)were performed at 40W?50w?60w?70w?80w?90w?100W for 10 minutes with three repetition.Temperatures of catheter and 10mm,15mm,20mm away from the antenna tip were measured respectively;(2)By antenna penetrated through the surface of ex vivo porcine lung,ablations(n=9)were performed at 70w?80w?90w for 10minutes with three repetition.Temperatures of catheter and 10mm,15mm,20mm away from the antenna tip were measured respectively.(3)Under the guidance of bronchoscope,flexible bronchoscopy-guided water-cooled MWA antenna was used to conduct microwave ablations(n=36)in the target bronchus and the around peripheral lung tissue of bilateral ex vivo porcine lungs through the working channel of bronchoscope individually.According to the parameters setting used(power and ablation time),the experiments were divided into 50w,60w,70w,80w groups and 3min,5min,8min groups,three times were repeated under each set parameter.(4)Under the guidance of bronchoscope,flexible bronchoscopy-guided water-cooled MWA antenna unite the extended work channel(EWC)was used to conduct microwave ablations(n=18,6 in ex vivo and 12 in vivo)in the target bronchus and the around peripheral lung tissue of bilateral ex vivo and vivo porcine lungs through the working channel of bronchoscope.All were performed at 80W for 5 minutes with three repetition.After ablation,all ablated peripheral lung tissue was cut open along the target bronchial lumen,and the long-axis diameter(Dl)and short-axis diameter(Ds)of the lesion were measured.Computed tomography(CT)was acquired perioperative,24hours,2weeks,4weeks.Ablation zones in vivo were excised at 24hours and 4weeks respectively and were sectioned for pathological examination.The data were analyzed with One-way ANOVA to compare group-to-group analysis,multi-factor and multi-level ANOVA in the whole group analysis,multivariate linear regression analysis and paired t-test were used.Results(1)In ex vivo liver,temperature and diameter had different changes between parameters(power,time)and increased with the increase of power and time respectively.(2)In ex vivo lung by penetrated through the surface,the temperature of 20mm was over 60?at 80W for 288±26seconds.(3)In the individually ablations under bronchoscopy,as the power increased(50-80w),Dl and Ds gradually increased(P<0.01);Dl and Ds also gradually increased with the increase of ablation time(3-8min)(P<0.01).There is a multiple linear relationship between power,time and Dl?Ds.The determination coefficient(R ~2)=0.91 and=0.85 respectively indicates that the model has a good fitting effect.A scoring model was established for predicting the size of the ablation range after parameter setting.(4)The ablations unite EWC under bronchoscopy were successful in ex vivo and vivo lung.Lesions had different show on CT at different time.No complications occurred during operation.Coagulation necrosis was visible at 24 hours,and repaired fibrous tissue was seen at 4 weeks.ConclusionThe flexible bronchoscopy-guided water-cooled MWA technique was confirmed to be feasible and safe,and it could achieve ideal ablation range according to different parameters(power and time).This new technology could become a potential interventional therapeutic tool in Peripheral Lung Tumors.