Methods and apparatus for tissue cryotherapy

Abstract

A method for performing cryotherapy on a target tissue region in a body includes positioning a first cooling element in a first location in a body adjacent a target tissue region, positioning a second cooling element in a second location in the body adjacent the target tissue region, and cooling the respective first and second cooling elements so as to cool the target tissue region.

1 . A method for performing cryotherapy on a target tissue region in a body, comprising: 
 positioning a first cooling element in a first location in a body adjacent a target tissue region;    positioning a second cooling element in a second location in the body adjacent the target tissue region; and    cooling the respective first and second cooling elements so as to cool the target tissue region.    
     
     
         2 . The method of  claim 1 , wherein the target tissue region is sufficiently cooled to be ablated.  
     
     
         3 . The method of  claim 1 , wherein the target tissue region is proximate an annulus of a mitral valve connecting a left atrium and left ventricle of a heart.  
     
     
         4 . The method of  claim 3 , wherein the target tissue region comprises a left atrial isthmus of the heart.  
     
     
         5 . The method of  claim 1 , wherein the target tissue region is proximate an annulus of a tricuspid valve connecting a right atrium and right ventricle of a heart.  
     
     
         6 . The method of  claim 1 , wherein the first location is in a coronary sinus and the second location is in a left atrium.  
     
     
         7 . The method of  claim 6 , wherein positioning the first cooling element in the coronary sinus comprises inserting the first cooling element in the coronary sinus and adjacent the target tissue region when the first cooling element is in a collapsed profile, and expanding the first cooling element to an expanded profile that substantially occludes the coronary sinus.  
     
     
         8 . The method of  claim 1 , wherein one or both of the cooling elements are expandable.  
     
     
         9 . The method of  claim 1 , wherein one or both of the first and second cooling elements are inflatable.  
     
     
         10 . The method of  claim 1 , one or both of the first and second locations comprising an atrium or ventricle of a heart.  
     
     
         11 . The method of  claim 1 , one or both of the first and second locations comprising a pulmonary vein or pulmonary vein opening.  
     
     
         12 . The method of  claim 1 , wherein cooling of the first cooling element is controlled independent of cooling of the second cooling element.  
     
     
         13 . The method of  claim 1 , wherein positioning the second cooling element comprises locating a portion of the first cooling element and verifying that the located portion is in contact with, or otherwise adjacent to, the target tissue region.  
     
     
         14 . The method of  claim 13 , wherein the portion of the first cooling element is located using a fluoroscope.  
     
     
         15 . The method of  claim 13 , wherein the portion of the first cooling element is located using ultrasound.  
     
     
         16 . The method of  claim 13 , wherein the portion of the first cooling element is located using electromagnetic or radiofrequency energy.  
     
     
         17 . The method of  claim 13 , wherein cooling the first cooling element comprises cooling the located portion.  
     
     
         18 . The method of  claim 1 , further comprising verifying a selected portion of the first cooling element is positioned proximate a selected portion of the second cooling element while or after the respective cooling elements are positioned adjacent the target tissue region.  
     
     
         19 . The method of  claim 1 , wherein the first location is inside a heart, and the second location is adjacent or on a surface of the heart.  
     
     
         20 . The method of  claim 19 , wherein the first location is inside an atria.  
     
     
         21 . The method of  claim 19 , wherein the second location is on an epicardium of the heart or within a pericardial sac.  
     
     
         22 . A method for treating atrial fibrillation, comprising: 
 positioning a first cooling element in a patient's coronary sinus adjacent a target tissue region at least partially connecting the patient's left atrium and left ventricle;    positioning a second cooling element in the patient's left atrium adjacent the target tissue region; and    cooling the respective first and second cooling elements so as to ablate the target tissue region.    
     
     
         23 . The method of  claim 22 , wherein the target tissue region comprises the patient's left atrial isthmus.  
     
     
         24 . The method of  claim 22 , wherein positioning the first cooling element in the coronary sinus comprises 
 inserting the first cooling element in the coronary sinus and adjacent the target tissue region when the first cooling element is in a collapsed profile, and    expanding the first cooling element to an expanded profile that substantially occludes the coronary sinus.    
     
     
         25 . The method of  claim 24 , wherein the first cooling element is expanded by inflating the first cooling element.  
     
     
         26 . The method of  claim 22 , wherein one or both of the first and second cooling elements are expandable.  
     
     
         27 . The method of  claim 26 , wherein cooling of the first cooling element is controlled independent of cooling of the second cooling element.  
     
     
         28 . The method of  claim 22 , further comprising locating a portion of the first cooling element and verifying that the located portion is in contact with, or otherwise adjacent to, the target tissue region.  
     
     
         29 . The method of  claim 28 , wherein cooling the first cooling element comprises cooling the located portion.  
     
     
         30 . The method of  claim 22 , further comprising verifying a selected portion of the first cooling element is positioned proximate a selected portion of the second cooling element while or after the respective cooling elements are positioned adjacent the target tissue region.  
     
     
         31 . The method of  claim 30 , wherein cooling the first and second cooling elements comprises cooling the respective selected portions.  
     
     
         32 . The method of  claim 22 , wherein the target tissue region is ablated by being synergistically cooled using the first and the second cooling elements.  
     
     
         33 . Apparatus for performing cryotherapy on a target tissue region in a body, comprising: 
 a first cooling element configured for positioning in a first location in a body adjacent a target tissue region, the first cooling element comprising a locatable portion;    a second cooling element configured for positioning in a second location in a body adjacent the target tissue region, the second cooling element comprising a locatable portion;    each of the first and second cooling elements being in fluid communication with a coolant source; and    one or more controllers for controlling cooling of the first and second cooling elements independent of each other.    
     
     
         34 . The apparatus of  claim 33 , wherein the first location is in a coronary sinus and the second location is in a left atrium.  
     
     
         35 . The apparatus of  claim 34 , wherein the first cooling element may be configured in a collapsed profile for positioning in the coronary sinus adjacent the target tissue region, and in an expanded profile that substantially occludes the coronary sinus.  
     
     
         36 . The apparatus of  claim 33 , wherein one or both of the first and the second cooling elements are expandable.  
     
     
         37 . The apparatus of  claim 33 , wherein one or both of the first and second cooling elements are inflatable.  
     
     
         38 . The apparatus of  claim 33 , further comprising a system for verifying whether the locatable portion of the first cooling element is in contact with, or otherwise adjacent to, the target tissue region.  
     
     
         39 . The apparatus of  claim 33 , wherein the locatable portion of the first cooling element may be selectively cooled.  
     
     
         40 . The apparatus of  claim 33 , further comprising a system for verifying whether the locatable portion of the first cooling element is positioned proximate the locatable portion of the second cooling element.  
     
     
         41 . The apparatus of  claim 33 , further comprising a third cooling element, wherein the first, second, and third cooling elements are configured such that two of the cooling elements are alternately placed in contact with the target tissue region while the remaining cooling element is being positioned.  
     
     
         42 . The apparatus of  claim 33 , wherein the first location is inside a heart and the second location is outside the heart.