Apparatus and methods for coronary sinus access

Abstract

Apparatus and methods for locating 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.

What is claimed is: 
     
         1 . A method for imaging a wall of a body cavity of a patient, comprising:
 inserting a distal end of a tubular member into the body cavity, the tubular member comprising a substantially transparent expandable member thereon in a contracted condition;   expanding the expandable member within the body cavity;   placing a distal surface of the expanded expandable member in contact with a wall of the body cavity in order to image the wall through a central region of the distal surface;   applying sufficient force to at least partially clear fluid from between the surface and the wall to enhance imaging the wall; and   manipulating the tubular member to move the expandable member along the wall, while imaging the wall through the central region of the distal surface.   
     
     
         2 . The method of  claim 1 , wherein the tubular member is manipulated to move the expandable member along the wall, while imaging the wall through the expandable member, until a desired body structure is centered within a field of view through the distal surface. 
     
     
         3 . The method of  claim 1 , wherein the entire distal surface of the expandable member is configured to be moved along the wall while imaging through the distal surface. 
     
     
         4 . The method of  claim 1 , wherein the tubular member is manipulated by steering the distal end of the tubular member from a proximal end of the tubular member. 
     
     
         5 . The method of  claim 1 , wherein the tubular member is manipulated to move the expandable member along the wall, while imaging the wall through the expandable member, until a desired body structure is identified. 
     
     
         6 . The method of  claim 5 , wherein an instrument is advanced to the desired body structure through the tubular member, the instrument comprising at least one of a lead, a guide wire, a cannula, and a catheter. 
     
     
         7 . The method of  claim 5 , wherein the desired body structure comprises a body lumen communicating with the body cavity, the method further comprising advancing an instrument from the tubular member into the body lumen. 
     
     
         8 . The method of  claim 7 , wherein the tubular member is manipulated to position the body lumen in a field of view through the central region of the distal surface of the expandable member, thereby substantially aligning a channel through the expandable member with the body lumen. 
     
     
         9 . The method of  claim 8 , wherein the instrument is advanced through the channel into the body lumen after the channel is substantially aligned with the body lumen. 
     
     
         10 . The method of  claim 7 , wherein the body cavity comprises a right atrium of a patient's heart, and wherein the body lumen comprises a coronary sinus ostium. 
     
     
         11 . The method of  claim 1 , further comprising delivering a fluid between the surface and the wall to at least partially clear bodily fluid from between the surface and the wall to enhance imaging the wall. 
     
     
         12 . A method for imaging a wall of a body cavity of a patient, comprising:
 inserting a distal end of a tubular member into the body cavity, the tubular member comprising a substantially transparent expandable member thereon in a contracted condition;   expanding the expandable member within the body cavity;   placing a surface of the expanded expandable member in contact with a wall of the body cavity in order to image the wall through a central region of a distal surface of the expandable member;   substantially stabilizing the distal end of the tubular member relative to the wall of the body cavity by advancing at least a portion of the tubular member to extend the distal end beyond the surface of the expanded expandable member; and   manipulating the tubular member to move the expandable member along the wall, while imaging the wall through the central region of the expandable member.   
     
     
         13 . The method of  claim 12 , wherein the distal end of the tubular member is stabilized by applying a distal force to the tubular member to press the expandable member against the wall to stabilize the distal end of the tubular member. 
     
     
         14 . The method of  claim 13 , wherein pressing the expandable member results in deformation of the expandable member, thereby substantially stabilizing the distal end of tubular member. 
     
     
         15 . The method of  claim 13 , further comprising imaging one or more tissue structures through the expandable member while the distal end of the tubular member is stabilized. 
     
     
         16 . The method of  claim 13 , wherein a portion of the expandable member is directed into a body lumen communicating with the body cavity when the distal force is applied to stabilize the distal end of the tubular member. 
     
     
         17 . The method of  claim 12 , wherein the distal end of the tubular member is stabilized by advancing an elongate member from the tubular member. 
     
     
         18 . The method of  claim 17 , wherein the elongate member is advanced from the tubular member into a body lumen communicating with the body cavity to stabilize the distal end of the tubular member. 
     
     
         19 . The method of  claim 17 , wherein the elongate member is advanced from the tubular member to engage a morphological feature to stabilize the distal end of the tubular member. 
     
     
         20 . An apparatus for imaging within a body lumen, comprising:
 a flexible tubular member comprising proximal and distal ends defining a longitudinal axis therebetween;   a substantially transparent expandable member on the distal end of the tubular member, the expandable member being expandable from a contracted condition to an enlarged condition when fluid is introduced through the tubular member into an interior of the expandable member; and   an optical imaging element disposed within the interior of the expandable member, the imaging element extending from the distal end of the tubular member in a direction at least partially transversely relative to the longitudinal axis.