Morphometric Ablation Lesion Characteristics Comparing 4, 6, and 8 mm Electrode‐Tip Cryocatheters

Abstract

Longer electrode-tip cryocatheters produce larger lesions of similar depth, with intact endothelial layers and absence of thrombosis. Surface areas and volumes may be particularly sensitive to catheter tip-to-tissue contact angles with larger electrodes, as reflected by greater variability with 8 mm tips.

Cryoablation of typical AVNRT: Younger age and administration of bonus ablation favor long-term success

“…In fact, a larger tip catheter is expected to create wider lesions, which are likely to be associated with less recurrences at follow-up. 15 In our series, the success rate at 12-month follow-up was 89.4%, which is comparable with previous experiences. 7 Two conditions resulted to be independently associated with the rate of recurrences: patients' age and the lack of bonus CA delivered.…”

Enlargement of Catheter Ablation Lesions in Infant Hearts With Cryothermal Versus Radiofrequency Energy

“…Such an approach overcomes limitations of formula-based estimates (eg, prolate ellipsoid) 17 and yields highly consistent results. 18,19 Using this methodology, we confirmed the observation by Saul et al that radiofrequency ablation in immature myocardium results in substantial enlargement of atrial and ventricular lesions but not AV groove lesions over time. Although underlying mechanisms remain unknown, it was speculated that expansion of radiofrequency ablation lesions may be driven in part by the serrated bordering zones 18,20,21 that produce multiple extensions of fibrous and elastic tissue into surrounding normal myocardium.…”

“…18,19,27 Acute lesion sizes and the extent of variability obtained by 4-mm electrode-tip radiofrequency and cryothermal ablation catheters, with cryoablation producing nonsignificantly smaller lesion volumes, are likewise compatible with prior observations in mature animals. 18,19 It is worth noting that although the study was powered to compare expansion rates of ablation lesions according to energy modality, analyses that further divide lesions into multiple subgroups (eg, by cardiac chamber and time of euthanasia) are limited by smaller sample sizes.…”

“…18,19 The postablation healing response is somewhat slower with radiofrequency energy, as replacement fibrosis is confined to the outer margin of lesions at 7 days, with lingering intralesional hemorrhage. 18,19 Radiofrequency ablation lesions become densely fibrotic by 1 month. 28 We had speculated that differences in the pathophysiology of acute injury and healing processes associated Figure 4.…”

Comparison of the Disordered Mechanical Function of the Left Atrium After Antral Isolation of Pulmonary Veins by Radiofrequency or Cryoballoon Ablation

“…Повреждение, вызванное криовоздействием, явля-ется более гомогенным, чем радиочастотное, характе-ризуется очерченной зоной некроза, менее выражен-ным тромбообразованием в связи с сохранностью эндокарда в месте воздействия [21,23,24]. Также установлено, что размер повреждения по площади сопоставим с диаметром используемого катетера при неизменной глубине повреждения [25]. Исходя из вышесказанного, можно предположить, что пре-диктором нарушения механической функции при РЧА является большой объем ЛП, а при криоабла-ции -малый.…”