Apparatus and methods for coronary sinus access

Abstract

Apparatus and methods for locating morphological features within a body cavity using a catheter including proximal and distal ends, a transparent balloon carried on the distal end, and an optical imaging assembly carried on the distal end for imaging through the balloon. The balloon includes a channel extending therethrough to a lumen extending through the catheter. A guidewire or other localization member is received in the lumen that is extendable through the channel. During use, the catheter is inserted into a right atrium of a heart, and the balloon is expanded and placed against the wall of the heart to locate the coronary sinus. Sufficient force is applied to clear blood between the surface and the wall and clear the field of view of the imaging assembly. The catheter is manipulated to locate the coronary sinus, whereupon the localization member is advanced into the coronary sinus.

1 . A method of assessing a tissue region of interest, comprising:
 inserting a distal end of a catheter into a blood-filled body lumen, the catheter having a barrier or membrane that is at least partially transparent and projecting from the catheter;   expanding the barrier or membrane with a transparent fluid from an insertion configuration to a deployed configuration;   contacting the tissue region with a distal surface of the barrier or membrane;   imaging the tissue region through the transparent fluid with an imaging element positioned within the barrier or membrane proximal to the distal surface;   sensing a physiological parameter of the tissue region via one or more electrodes extending along the barrier or membrane such that the electrodes contact the tissue region when the barrier or membrane is expanded; and   repositioning the barrier or membrane along the tissue region depending upon the physiological parameter sensed by the one or more electrodes while maintaining visualization of the tissue region.   
     
     
         2 . The method of  claim 1 , wherein inserting comprises intravascularly advancing the distal end into a chamber of a heart. 
     
     
         3 . The method of  claim 1 , wherein expanding comprises inflating the barrier or membrane with the transparent fluid. 
     
     
         4 . The method of  claim 1 , wherein contacting further comprises advancing an instrument from the catheter. 
     
     
         5 . The method of  claim 4 , wherein advancing an instrument from the catheter comprises advancing a guidewire from the catheter. 
     
     
         6 . The method of  claim 4 , wherein advancing an instrument from the catheter comprises stabilizing the distal end of the catheter relative to the tissue region via the instrument. 
     
     
         7 . The method of  claim 1 , further comprising delivering a fluid between the distal surface and the tissue region to at least partially clear blood such that imaging of the tissue region is enhanced. 
     
     
         8 . The method of  claim 1 , further comprising infusing a therapeutic agent into the tissue region. 
     
     
         9 . The method of  claim 1 , wherein sensing a physiological parameter of the tissue region comprises detecting an oxygen level of the tissue region. 
     
     
         10 . The method of  claim 1 , wherein repositioning the barrier or membrane comprises manipulating the barrier or membrane to move along the tissue region while maintaining visualization through the barrier or membrane until a second location of the tissue region is located. 
     
     
         11 . The method of  claim 1 , wherein repositioning the barrier or membrane comprises reconfiguring the barrier or membrane from its deployed configuration to its insertion configuration. 
     
     
         12 . A method of assessing a tissue region of interest, comprising:
 inserting a distal end of a catheter into a blood-filled body lumen, the catheter having a barrier or membrane that is at least partially transparent and projecting from the catheter;   expanding the barrier or membrane with a transparent fluid from an insertion configuration to a deployed configuration;   imaging the tissue region contacted against the barrier or membrane through the transparent fluid with an imaging element positioned within the barrier or membrane proximal to the distal surface;   sensing a physiological parameter of the tissue region via one or more electrodes extending along the barrier or membrane; and   repositioning the barrier or membrane along the tissue region depending upon the physiological parameter sensed by the one or more electrodes while maintaining visualization of the tissue region.   
     
     
         13 . The method of  claim 12 , wherein inserting a distal end of a catheter comprises intravascularly advancing the distal end into a chamber of a heart. 
     
     
         14 . The method of  claim 12 , wherein expanding the barrier or membrane comprises inflating the barrier or membrane with the transparent fluid. 
     
     
         15 . The method of  claim 12 , wherein contacting the tissue region further comprises advancing an instrument from the catheter. 
     
     
         16 . The method of  claim 15 , wherein advancing an instrument from the catheter comprises advancing a guidewire from the catheter. 
     
     
         17 . The method of  claim 15 , wherein advancing an instrument from the catheter comprises stabilizing the distal end of the catheter relative to the tissue region via the instrument. 
     
     
         18 . The method of  claim 12 , further comprising delivering a fluid between the distal surface and the tissue region to at least partially clear blood such that imaging of the tissue region is enhanced. 
     
     
         19 . The method of  claim 12 , wherein repositioning the barrier or membrane comprises manipulating the barrier or membrane to move along the tissue region while maintaining visualization through the barrier or membrane until a second location of the tissue region is located. 
     
     
         20 . The method of  claim 12 , wherein repositioning comprises reconfiguring the barrier or membrane from its deployed configuration to its insertion configuration.