Cryo balloon

#The present invention pertains generally to the field of cryo therapy. More particularly, the present invention pertains to cryo ablation catheters for use in causing cold-induced necrosis and cryoplasty catheters for use in causing apoptosis to prevent restenosis.

#A number of medical conditions may be treated using ablative techniques or devices. Ablative techniques, generally, result in destroying the function of abnormal tissue at an area of interest. Destroying the function of the abnormal tissue may result in an efficacious treatment for a medical condition. For example, atrial fibrillation may be the result of abnormal electrical activity in the left atrium and the pulmonary vein, and may be treatable by ablation of the abnormal tissue within the left atrium and/or the pulmonary vein.

#Atrial fibrillation is a serious medical condition that is the result of abnormal electrical activity within the heart. This abnormal activity may occur at regions of the heart including the sino-atrial (SA) node, the atriovenricular (AV) node, the bundle of His, or within other areas of cardiac tissue. Moreover, atrial fibrillation may be caused by abnormal activity within a isolated focal center within the heart. It is believed that these foci can originate within the pulmonary vein, particularly the superior pulmonary veins.

#FIG. 1 is a cross-section of a cryo therapy device having a pressure gauge and a pressure release tube;

#FIG. 2 is a partial cross-section of a cryo therapy device having a fuse link coupled to the pressure relief tube;

#FIG. 3 is a partial cross-section of a cryo therapy device having a relief cutter coupled to the inner surface of the inner member of the cooling chamber; and

#The following description should be read with reference to the drawings wherein like reference numerals indicate like elements throughout the several views. The detailed description and drawings represent select embodiments and are not intended to be limiting.

#FIG. 1 is a cross-section of a cryo therapy device 10 having a pressure gauge 12 and a pressure release tube 14. Pressure gauge 12 is coupled to a cooling member 16, for example on an inner member 26. Pressure gauge 12 may be used to quantify pressure within cooling member 16. Cooling member 16 is coupled to an elongate shaft 18. In addition, at least a portion of pressure relief tube 14 is disposed within cooling member 16. Pressure relief tube 14 may be used to release inflation/cooling media from cooling member 16. This could be done, for example, when the pressure in cooling member 16 as detected by gauge 12 is in excess of a desired limit.

#Cryo therapy device 10 may use heat transfer to perform a number of procedures including pulmonary vein ablation, pulmonary artery ablation, atrial fibrillation, arrhythmia, and other conditions. Moreover, cryo therapy device 10 may be used to prevent restenosis in the vasculature (including the pulmonary artery and vein), cardiac tissue (including atria and ventricles), and other target regions where cryoplasty may have beneficial effects.