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Experimental Study of Enhance the Effectiveness of Radiofrequency Ablation

Author: WangKe
Tutor: HuangNaiXiang
School: PLA Military Academy of Medical Sciences
Course: Oncology
Keywords: radiofrequency ablation Nacl solution Cacl2 solution cell apoptosis
CLC: R730.5
Type: Master's thesis
Year: 2009
Downloads: 32
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Abstract

Objective: To investigate the feasibility and effect of radiofrequency ablation (RFA) with Nacl and Cacl2 solution of pulmonary tissue of pigs compared to convention RFA.Methods: Twenty-four fresh pulmonary tissue of pigs were divided into three groups: RFA group(n=8), Nacl-enhanced RFA group(n=8) and Cacl2– enhanced RFA group(n=8) .Lesions were created using a 500-kHz RF generator(Rita) capable of producing 200 W of power. Power output was set at 30W , and RF energy was applied for 5 minutes to maintain an average temperature of 70℃. Before and during the procedure, A peristaltic pump was used to infuse 5% Nacl and 5% Cacl2 solution to the lumen of the clectrode at a rate of 15 dripping/min respectively. a thermocouple embedded within the electrode tip continuously measured the local tissue temperature, and tissue impedance was monitored by circuitry incorporated within the generator . The healing process were studied. The gross specimens and the central discolored region of coagulation necrosis in each specimen were histopathologic examined. Tissues were then fixed in 10% formalin for routine histologic examination, and final processing for light microscopic study involved hematoxylin-eosin (HE) and terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling (TUNEL )staining respectively. The technical aspects of RFA and effect were compared for three techniques. For all statistical analysis, SPSS 11.0 computer software was used, and a p value of less than 0.05 was considered statistically significant.Results: 1) In the RFA group, the time achieved the target temperature was longer than the other groups(P<0.01); the time between the Nacl and the Cacl2 groups had no significantly change(P>0.05). 2)In the RFA group, the initial tissue impedance was higher than the he Nacl and the Cacl2 groups(P<0.01). During the procedure of three groups, the impedance heightened and the impedance of RFA group changed markedly. The impedance of Cacl2 group was lower slightly than that of Nacl group(P>0.05). 3)The output power was decreased with the procedure of RFA in three groups, and decreased sharper in the RFA group than the other groups(P<0.01).But the output power between the Nacl and the Cacl2 groups had no significantly changes(P>0.05). 4)Histological examination of a lesion revealed a central charred zone with complete destruction of the parenchyma and a peripheral hemorrhagic rim and a normal tissue . The diameter of lesion in the Cacl2 group was largger than the other groups(P<0.01). 5)HE staining results of three groups showed that typical findings of coagulation necrosis were observed. 6)TUNEL staining results showed that the cell apoptosis index (AI)before the RFA less than that after the RFA in three group(sP<0.01). The AI of Cacl2 groups was larger than that of the other groups(P<0.01).Conclusion: 1) The initial tissue impedance observed lower and maintained the longer time and the output power was higher and the time achieved the target temperature was shorter in the procedure of RFA with Nacl and the Cacl2 infusion, compared the RFA. 2) The diameter of les ion and the ablation effect in the procedure of RFA with Nacl infusion enlarged. 3) The diameter of lesion and the ablation effect in the procedure of RFA with Cacl2 infusion enlarged. And that more apoptosis cells were finded in the lesion. 4) The ablation effect in the procedure of RFA with Cacl2 infusion was stronger than that of with Nacl infusion.

Experimental Study of Enhance the Effectiveness of Radiofrequency Ablation

Abstract

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