Abstract: Tissue piercing devices and methods for using the same are described. The tissue piercing devices may be adapted to pierce through the septal wall to create a pathway between the right and left atria. The tissue piercing devices may include one or more visualization elements to visualize a target puncture site on the septal wall, such as within the fossa ovalis. The devices that may include an inner volume adapted to hold a piercing member and the one or more visualization elements therein. One or more components of the tissue piercing apparatus may be steerable to steer the piercing member toward the target puncture site. In some examples, the tissue piercing devices may include an inflatable member that is expandable upon inflation to form the inner volume.

Abstract: A cryotherapy catheter can include an elongate member and an inflatable balloon at a distal end of the elongate member, the elongate member having lumens formed therein to supply cryogenic fluid to a chamber of the balloon and to channel exhaust from the balloon chamber; and a controller programmed to control a first rate at which the cryogenic fluid is supplied to the balloon chamber and a second rate at which exhaust is channeled from the balloon chamber, wherein the controller is programmed to a) develop, during a first phase of a cryotherapy procedure, a first pressure inside the balloon chamber at a value that is greater than an ambient pressure outside and adjacent to a proximal end of the elongate member, and b) develop, during a second phase of the cryotherapy procedure, the first pressure at a value that is less than the ambient pressure.

Abstract: A cryotherapy catheter can include an elongate member and an inflatable balloon at a distal end of the elongate member, the elongate member having lumens formed therein to supply cryogenic fluid to a chamber of the balloon and to channel exhaust from the balloon chamber; and a controller programmed to control a first rate at which the cryogenic fluid is supplied to the balloon chamber and a second rate at which exhaust is channeled from the balloon chamber, wherein the controller is programmed to a) develop, during a first phase of a cryotherapy procedure, a first pressure inside the balloon chamber at a value that is greater than an ambient pressure outside and adjacent to a proximal end of the elongate member, and b) develop, during a second phase of the cryotherapy procedure, the first pressure at a value that is less than the ambient pressure.

Abstract: A cryotherapy catheter can include an elongate member and an inflatable balloon at a distal end of the elongate member, the elongate member having lumens formed therein to supply cryogenic fluid to a chamber of the balloon and to channel exhaust from the balloon chamber; and a controller programmed to control a first rate at which the cryogenic fluid is supplied to the balloon chamber and a second rate at which exhaust is channeled from the balloon chamber, wherein the controller is programmed to a) develop, during a first phase of a cryotherapy procedure, a first pressure inside the balloon chamber at a value that is greater than an ambient pressure outside and adjacent to a proximal end of the elongate member, and b) develop, during a second phase of the cryotherapy procedure, the first pressure at a value that is less than the ambient pressure.

Abstract: Apparatus and methods for cooling liquid coolant, such as nitrous oxide, to be delivered to a cryo-ablation device such as a balloon catheter. A hose or conduit in fluid communication with the ablation device includes an outer member and inner tubes. A first inner tube disposed within a lumen of the outer member carries liquid coolant to the ablation device. Another inner tube also disposed within the lumen carries liquid coolant and terminates within the lumen such that gaseous coolant derived from liquid coolant flowing through the second inner tube flows within the lumen to cool or chill the first inner tube and liquid coolant carried by the first inner tube to the ablation device.

Abstract: Apparatus and methods for cooling liquid coolant, such as nitrous oxide, to be delivered to a cryo-ablation device such as a balloon catheter. A hose or conduit in fluid communication with the ablation device includes an outer member and inner tubes. A first inner tube disposed within a lumen of the outer member carries liquid coolant to the ablation device. Another inner tube also disposed within the lumen carries liquid coolant and terminates within the lumen such that gaseous coolant derived from liquid coolant flowing through the second inner tube flows within the lumen to cool or chill the first inner tube and liquid coolant carried by the first inner tube to the ablation device.

Abstract: Apparatus and methods for cooling liquid coolant, such as nitrous oxide, to be delivered to a cryo-ablation device such as a balloon catheter. A hose or conduit in fluid communication with the ablation device includes an outer member and inner tubes. A first inner tube disposed within a lumen of the outer member carries liquid coolant to the ablation device. Another inner tube also disposed within the lumen carries liquid coolant and terminates within the lumen such that gaseous coolant derived from liquid coolant flowing through the second inner tube flows within the lumen to cool or chill the first inner tube and liquid coolant carried by the first inner tube to the ablation device.

Abstract: A cryotherapy catheter can include an elongate member and an inflatable balloon at a distal end of the elongate member, the elongate member having lumens formed therein to supply cryogenic fluid to a chamber of the balloon and to channel exhaust from the balloon chamber; and a controller programmed to control a first rate at which the cryogenic fluid is supplied to the balloon chamber and a second rate at which exhaust is channeled from the balloon chamber, wherein the controller is programmed to a) develop, during a first phase of a cryotherapy procedure, a first pressure inside the balloon chamber at a value that is greater than an ambient pressure outside and adjacent to a proximal end of the elongate member, and b) develop, during a second phase of the cryotherapy procedure, the first pressure at a value that is less than the ambient pressure.

Abstract: A cryotherapy catheter can include an elongate member and an inflatable balloon at a distal end of the elongate member, the elongate member having lumens formed therein to supply cryogenic fluid to a chamber of the balloon and to channel exhaust from the balloon chamber; and a controller programmed to control a first rate at which the cryogenic fluid is supplied to the balloon chamber and a second rate at which exhaust is channeled from the balloon chamber, wherein the controller is programmed to a) develop, during a first phase of a cryotherapy procedure, a first pressure inside the balloon chamber at a value that is greater than an ambient pressure outside and adjacent to a proximal end of the elongate member, and b) develop, during a second phase of the cryotherapy procedure, the first pressure at a value that is less than the ambient pressure.

Abstract: A method of performing a catheter-based procedure can include introducing a delivery sheath inside a patient's body and advancing a secondary sheath through the delivery sheath, toward a treatment site inside the patient's body. The secondary sheath can be distinct from the delivery sheath, coaxial to the delivery sheath along at least a portion of a length of the delivery sheath, and can have a default linear shape that is substantially free of radial bias. The method can further include introducing a catheter through the delivery sheath and secondary sheath, to the treatment site, and performing a procedure at the treatment site with the catheter. Performing the procedure can include performing the procedure while maintaining at a relatively fixed position the secondary sheath.

Abstract: A method, system, and device for detecting whether an expandable member completely occludes an anatomic passageway allows a user, such as a physician, clinician, or surgeon, to perform a medical procedure more efficiently and increases the procedure's chances of success. An incomplete occlusion can be immediately detected by monitoring the pressure difference across the expandable member. Through this method, a user can quickly diagnose the problem and reposition the expandable member in the anatomic passageway. In particular, in a cryoablation procedure, devices incorporating this method can help ensure a uniform and complete lesion in the pulmonary vein to electrically isolate the pulmonary vein from the atrium, thus preventing atrial fibrillation.

Abstract: A method of performing cryotherapy on a patient can include positioning an outer surface of a distal portion of a cryotherapy catheter in contact with body tissue to be treated; performing a treatment phase, including regulating a temperature of the outer surface at a treatment value for a first period of time; performing a recovery phase comprising allowing the temperature of the outer surface to warm up to a recovery value that is higher than treatment value but substantially lower than a normal body temperature of the patient; and performing one or more additional treatment phases for a second period of time. Each of the first and second periods of time can be selected to allow a cold front having a cold front temperature to propagate from the outer surface and through a therapeutic portion of a thickness of the body tissue, but not substantially beyond the thickness.

Abstract: A sheath attached to a guide wire, a tubular shaft member slidable on the guide wire and a filtering assembly constricted within the sheath are movable in a vessel to a position distal to a lesion in the direction of fluid flow. The filtering assembly may be formed from a plurality of angularly spaced splines and a mesh disposed on the splines having properties of passing fluid in the vessel while blocking the passage of emboli in the fluid. The splines may be provided with shape memory for expanding against the wall of the vessel when released from constriction by the sheath. The sheath may be moved relative to the filtering assembly and the support member to release the filter for expansion against the vessel wall. An interventional device can be used to treat the lesion. Any emboli released into the vessel as a result of the interventional treatment are blocked by the filter member while fluid is allowed to pass there through.

Abstract: A method of performing a catheter-based procedure can include introducing a delivery sheath inside a patient's body and advancing a secondary sheath through the delivery sheath, toward a treatment site inside the patient's body. The secondary sheath can be distinct from the delivery sheath, coaxial to the delivery sheath along at least a portion of a length of the delivery sheath, and can have a default linear shape that is substantially free of radial bias. The method can further include introducing a catheter through the delivery sheath and secondary sheath, to the treatment site, and performing a procedure at the treatment site with the catheter. Performing the procedure can include performing the procedure while maintaining at a relatively fixed position the secondary sheath.

Abstract: A method of performing cryotherapy on a patient can include positioning an outer surface of a distal portion of a cryotherapy catheter in contact with body tissue to be treated; performing a treatment phase, including regulating a temperature of the outer surface at a treatment value for a first period of time; performing a recovery phase comprising allowing the temperature of the outer surface to warm up to a recovery value that is higher than treatment value but substantially lower than a normal body temperature of the patient; and performing one or more additional treatment phases for a second period of time. Each of the first and second periods of time can be selected to allow a cold front having a cold front temperature to propagate from the outer surface and through a therapeutic portion of a thickness of the body tissue, but not substantially beyond the thickness.

Abstract: A cryotherapy catheter can include an elongate member and an inflatable balloon at a distal end of the elongate member, the elongate member having lumens formed therein to supply cryogenic fluid to a chamber of the balloon and to channel exhaust from the balloon chamber; and a controller programmed to control a first rate at which the cryogenic fluid is supplied to the balloon chamber and a second rate at which exhaust is channeled from the balloon chamber, wherein the controller is programmed to a) develop, during a first phase of a cryotherapy procedure, a first pressure inside the balloon chamber at a value that is greater than an ambient pressure outside and adjacent to a proximal end of the elongate member, and b) develop, during a second phase of the cryotherapy procedure, the first pressure at a value that is less than the ambient pressure.

Abstract: A method, system, and device for detecting whether an expandable member completely occludes an anatomic passageway allows a user, such as a physician, clinician, or surgeon, to perform a medical procedure more efficiently and increases the procedure's chances of success. An incomplete occlusion can be immediately detected by monitoring the pressure difference across the expandable member. Through this method, a user can quickly diagnose the problem and reposition the expandable member in the anatomic passageway. In particular, in a cryoablation procedure, devices incorporating this method can help ensure a uniform and complete lesion in the pulmonary vein to electrically isolate the pulmonary vein from the atrium, thus preventing atrial fibrillation.

Abstract: Apparatus and methods for cooling liquid coolant, such as nitrous oxide, to be delivered to a cryo-ablation device such as a balloon catheter. A hose or conduit in fluid communication with the ablation device includes an outer member and inner tubes. A first inner tube disposed within a lumen of the outer member carries liquid coolant to the ablation device. Another inner tube also disposed within the lumen carries liquid coolant and terminates within the lumen such that gaseous coolant derived from liquid coolant flowing through the second inner tube flows within the lumen to cool or chill the first inner tube and liquid coolant carried by the first inner tube to the ablation device.

Abstract: A sheath attached to a guide wire, a tubular shaft member slidable on the guide wire and a filtering assembly constricted within the sheath are movable in a vessel to a position distal to a lesion in the direction of fluid flow. The filtering assembly may be formed from a plurality of angularly spaced splines and a mesh disposed on the splines having properties of passing fluid in the vessel while blocking the passage of emboli in the fluid. The splines may be provided with shape memory for expanding against the wall of the vessel when released from constriction by the sheath. The sheath may be moved relative to the filtering assembly and the support member to release the filter for expansion against the vessel wall. An interventional device can be used to treat the lesion. Any emboli released into the vessel as a result of the interventional treatment are blocked by the filter member while fluid is allowed to pass there through.

Abstract: A sheath attached to a guide wire, a tubular shaft member slidable on the guide wire and a filtering assembly constricted within the sheath are movable in a vessel to a position distal to a lesion in the direction of fluid flow. The filtering assembly may be formed from a plurality of angularly spaced splines and a mesh disposed on the splines having properties of passing fluid in the vessel while blocking the passage of emboli in the fluid. The splines may be provided with shape memory for expanding against the wall of the vessel when released from constriction by the sheath. The sheath may be moved relative to the filtering assembly and the support member to release the filter for expansion against the vessel wall. An interventional device can be used to treat the lesion. Any emboli released into the vessel as a result of the interventional treatment are blocked by the filter member while fluid is allowed to pass there through.