Use of the Saline Infusion Electrode Catheter for Improved Energy Delivery and Increased Lesion Size in Radiofrequency Catheter Ablation

Abstract

Although radiofrequency catheter ablation has undergone explosive growth as the treatment for a variety of arrhythmias, a limiting factor with the existing catheter delivery system has been the relatively small size of the lesions, which appears to be in part due to coagulum formation around the catheter tip, producing a rise in impedance and limiting energy delivery. In order to test the hypothesis that infusion of saline during radiofrequency current application can increase the lesion size and decrease the incidence of impedance rise, ten dogs were each given two radiofrequency ablation lesions to the left ventricular endocardium. One of these lesions was delivered with a standard 7 French quadripolar catheter with a 2-mm tip, and the second was done with a 7 French luminal electrode catheter (also with a 2-mm tip) for the infusion of normal saline during the delivery of radiofrequency energy. Energy was delivered for 60 seconds at either 10 or 20 watts at two distinct sites in the left ventricle for each animal. Four to 7 days following ablation, the animals were sacrificed for pathological examination. The lesions created with the saline infusion catheter were significantly bigger than those produced with a standard catheter (7.3 x 7.0 x 5.1 vs 5.2 x 4.9 x 3.5 mm, respectively, P < 0.001). At the lower energy level (10 W), none of the animals with the saline infusion catheter experienced an impedance rise versus 3 of 5 of the animals in whom the standard catheter was used.(ABSTRACT TRUNCATED AT 250 WORDS)

Ex VivoExperiment on Radiofrequency Liver Ablation with Saline Infusion through a Screw-Tip Cannulated Electrode

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saline into the tissue through the hollow electrode tip Purpose: To investigate whether radiofrequency [6][7][8]. The conductivity of normal saline is 3 to 5 times (RF) therapy with hypertonic saline infusion through higher than that of the blood and 12 to 15 times higher a hollow screw-tip electrode can cause a lesion size than that of tissues.

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Temperature-Controlled Cooled-Tip Radiofrequency Ablation in Left Ventricular Myocardium Avoidance of Steam Pop During Ablation

“…17) To the best of our knowledge, only one previous study has presented subacute phase lesion dimensions at 4-7 days after RF ablation by saline irrigated catheter. 18) However, no previous study has compared acute and chronic phase lesion dimensions. Study limitations: This study has several limitations.…”

Saline-Cooled Versus Standard Radiofrequency Catheter Ablation for Infarct-Related Ventricular Tachycardias

“…Comparison of early success rates with previous studies 12,13 is difficult because success is often reported as the ablation of a "targeted" or "clinical" VT, without regard to the presence of other inducible VTs. The efficacy of standard RF was similar to that observed in a previous study of 52 patients from our group.…”