Treatment of atrioventricular nodal re-entrant tachycardia by cryoablation with a 6 mm-tip catheter vs. radiofrequency ablation

Abstract

Compared with RF ablation, CRYO with 6 mm-tip catheter for treating AVNRT results in higher recurrence and potentially lower incidence of permanent AVB. Fluoroscopy time has been shown to be reduced by CRYO.

Cryoablation Versus Radiofrequency Energy for the Ablation of Atrioventricular Nodal Reentrant Tachycardia (the CYRANO Study)

“…Several retrospective series 8,12,16,17 did not find a significant difference in procedure duration between cryoablation and RF, and only Chan et al 16 reported a significantly shorter fluoroscopy time in the cryoablation group (18 versus 26 minutes). In our experience, the longer procedure duration is not so much due to the time needed to install the cryoablation console and start the system but more to the time needed to perform multiple cryoablation mappings (each of 3 minutes' duration) with a large number of sites sometimes tested before ablating.…”

“…4,7,8,10 -13,15 Several authors report that using a 4-mm-tip ablation catheter achieved only moderate success rates, 11,12 whereas in more recent series with 6-mm-tip cryoablation catheters, short-term success rates of 93% to 99% were reached. 13,16,17 We used a 6-mm-tip catheter, an ablation time of 4 minutes, and a bonus freeze at the site of successful ablation. With this practice, a high short-term success rate (96.8%) comparable to RFCA (98.4%) was found.…”

“…Several other groups have described the problem of AVNRT recurrence after cryoablation in the range of 8% to 20%, which seems hard to accept compared with the significantly lower recurrence risk with RF. [11][12][13][14]16,17 The most likely reason for the high recurrence rate after cryoablation is the different type of acute and the smaller size of definitive ablation lesions. Cryoablation leads to a more homogenous lesion with intact, smooth endothelium and the absence of a big colliquation necrosis.…”

Catheter Cryoablation

“…In a systematic review that combined 22 published studies (including 2654 patients), cryothermal ablation had a high procedural success rate (95%; range, 85%-99%) that was comparable with RFCA (95%-98%). [30][31][32][35][36][37][38][39][40][41][42][43][44][45][46][47] Long-term freedom from recurrent arrhythmia with cryoablation was reported to be 89% (range, 81.3%-98%), which was lower than historical observations with RF (3%-7% recurrence). 32 Although historical comparisons between observational studies are fraught with potential biases, 11 comparative studies between cryothermy and RFCA for AVNRT (8 retrospective observational studies and 3 prospective randomized studies; Table 1), reported comparable acute success rates.…”

“…32 Although historical comparisons between observational studies are fraught with potential biases, 11 comparative studies between cryothermy and RFCA for AVNRT (8 retrospective observational studies and 3 prospective randomized studies; Table 1), reported comparable acute success rates. [36][37][38][39][40][41][42][43][44][45][46][47] Although the longer term recurrence rate was statistically similar in 7 of the 11 studies, there was an overall trend that favored RFCA. Procedural duration was globally similar, with a shorter fluoroscopy time with cryoablation.…”