Introduction: It has been suggested that pulmonary vein (PV) stenosis is a rare complication of cryoballon ablation (CB). However, PVs stenosis frequency could be higher in mixed procedures in which radiofrequency (RF) is used to complete the isolation following pulmonary vein cryoablation.
Methods: We analyzed the incidence of PV stenosis in 48 patients with drug-refractory paroxysmal atrial fibrillation (AF), who underwent in our center to ablation of VPs with mixed approach: initial CB, and additional RF with irrigated catheter (25 to 35 W) to complete the gaps if it were necessary. All patients had undergone cardiac computed tomography (CT) before ablation for detailing the anatomy and ostium diameter of PVs. Between 3 and 6 months post-procedure, we performed a cardiac magnetic resonance (CT in four patients) to evaluate the possible reduction in the VPs diameter regarding the prior study conducted before the ablation procedure.
Results: Of the 158 target PVs, 40 (25%) required additional radiofrequency to complete the isolation. PVs stenosis was only observed in two PVs (1.3%), one mild and one moderate, and both veins were left inferior pulmonary veins. In the PVs with stenosis the cryoablation had been undertaken as single procedure, using a balloon of 23mm in diameter for the vein that developed mild stenosis and one of 28mm in which presented moderate stenosis. None of the stenosis provoked symptoms. There was no PVs stenosis in the group with additional RF application after the cryoablation.
Conclusions: PVs stenosis is a rare complication of atrial fibrillation ablation with cryoballoon. In our experience, additional RF application after cryoablation to achieve complete isolation of PVs was not associated with an increased incidence of stenosis