PROTOCOL FOR COMPLETE CIRCUMFERENTIAL ISOLATION OF THE PULMONARY VEINS USING BALLOON CATHETER CRYOABLATION
Pulmonary Vein Isolation (PVI), with its disconnection of the left atrial muscle from the arrhythmogenic activity of the pulmonary veins, is the cornerstone of a definitive curative treatment in patients with persistently recurrent and symptomatic paroxysmal atrial fibrillation (PAF) in the absence of structural cardiopathy resistant to or intolerant to optimum treatment with antiarrhythmic drugs.
The application of extreme COLD affects the TISSUE MICROVASCULATURE through endothelial injury (expansion of the ice crystals inside produces tears, ruptures, cracks and fissures with post-reperfusion leakage and stasis), stopping the supply of cell nutrients and resulting in HISTOLOGICAL INJURY.
Catheter or Balloon-Catheter Cryoablation has revealed itself to be safe in animals and humans without the risk of complications described with Radiofrequency (RF) ablation (atrioesophageal fistula, stenosis of pulmonary veins, post-ablation atrial arrhythmias and thromboembolism), allowing complete circumferential isolation of the atrial–PV junction in the antrum of the pulmonary veins.
We use a 28 mm, 10.5 Arctic Front Balloon Catheter from CryoCath Technologies, Montreal, Quebec, Canada with a dual camera that allows the flow of nitrous oxide at very low temperatures (-30/-75), in such a way that the refrigerant vapor absorbs heat from the adjacent tissue that surrounds it, causing it to freeze. After every application, the vapor is discharged to outside the system.
The cold source is delivered through a console with an adjustable monitor continuously supplying, among other parameters, data on the temperature reached, expression of which is a function of the degree of occlusion desired and the duration of application.
STUDIES PERFORMED PRIOR TO THE PROCEDURE:
- Transthoracic echocardiogram.
- Transesophageal echocardiogram at least 48 hours before the procedure.
- High resolution CT scan (64 slices) (Toshiba Aquilion 64, TSX-101A).
- MRI-based (1.5 T/Magnetom Symphony, Siemens) characterization of anatomy/ number and caliber/pulmonary veins.
- Prior medical history / acute cerebrovascular accident.
- Blood vessel damage / cryoglobulinemia, coagulation.
- Presence of intracavitary thrombus.
- Associated comorbidity.
Description of Atrial Fibrillation
Prognosis and treatment of Atrial Fibrillation
Cryoablation procedure with commentary by Dr. Jesús M. Paylos
Contraindications for cryoablation