不同压力和功率体外消融对射频消融损伤的影响

Effect of power and contact forces on ablation lesion dimensions

目的通过体外消融实验验证不同压力和功率对射频消融损伤的影响。方法使用SmartTouch;导管,以不同导管贴靠力(低1~3 g、中5~15 g、高15~20 g)在不同功率(低30、中40、高50 W)下对猪心心外膜侧进行射频消融至目标消融指数(AI)值(350、450、500),测量消融灶宽度和深度,并计算体积。结果射频消融中,AI与消融灶最大内径、深度及体积呈正相关(r=0.66、0.7、0.7,P<0.05);在固定压力、AI为350,功率为40 W时,消融产生的消融灶较大[表面直径(4.38±0.37)mm,最大内径(5.49±0.37)mm,深度(3.31±0.20)mm,体积(41.61±5.30)mm^(3)];在固定功率下,低压力组的病灶尺寸明显变小,而中等压力组和高压力组两组之间无明显差异;低压力(1~3 g)、高功率(50 W)消融,蒸汽爆裂发生率100%,而高压力(15~20 g)消融时未出现蒸汽爆裂。结论对于压力监测导管,在功率和压力较低时,消融灶体积、深度随其增加而增大,但当压力、功率较高时,消融灶体积反而减小。低压力消融的损伤较小,而在高功率高AI条件下,高压力消融安全性较好。

Objective To verify the influences of different settings(forces and power)which have effect on radiofrequency ablation lesion through in vitro ablation experiments.Method Using an in vitro model,the experiment was performed with a combination of various powers(30,40,and 50 W)and contact forces(CFs)(1-3,5-15,and 15-20 g)5 times for each setting useing SmartTouch;catheter to reach diverse target ablation index(AI=350,450,and 500).Measured the width and depth of the ablation lesion,and calculated the volume.The correlation between the lesion formation and ablation parameters was evaluated.Results In radiofrequency ablation,AI was positively correlated with the maximum diameter,depth and volume of ablation lesion(r=0.66,0.7,0.7 respectively,all P<0.05);At fixed CF,lesion dimensions increased with power set at 40 W compared with 30 W but decreased with high-power RF energy(50 W),when contact force was 5-15 g and power was 40 W,the ablation lesion was the largest[surface diameter=(4.38±0.37)mm,maximum inner diameter=(5.49±0.37)mm,depth=(3.31±0.20)mm,volume=(41.61±5.30)mm^(3)].Furthermore,at fixed power,lesion dimensions significantly smaller in LCF group,whereas did not differ between MCF and HCF groups;low contact force(1-3 g)with high power setting,the incidence of steam pop was 100%,while the high contact force group(15-20 g)did not appear steam pop when power was high.Conclusion For SmartTouch;catheter,lesion volume is increased along with the early increase of CF and power,whereas further increase of CF and power significantly reduces the lesion size.The ablation lesions are smaller when contact force is low(1-3 g).Besides,in the condition of high power and high target AI,catheter force between 15 g and 20 g performes better and safer than other two groups.