Method and apparatus for improving mitral valve function

Abstract

A method and apparatus for reducing mitral regurgitation. The apparatus is inserted into the coronary sinus of a patient in the vicinity of the posterior leaflet of the mitral valve, the apparatus being adapted to straighten the natural curvature of at least a portion of the coronary sinus in the vicinity of the posterior leaflet of the mitral valve, whereby to move the posterior annulus anteriorly and thereby improve leaflet coaptation and reduce mitral regurgitation.

1 . An assembly for reducing mitral regurgitation, the assembly comprising: 
 an elongated carrier of material sufficiently flexible to assume a first configuration generally conforming to a coronary sinus upon insertion of said carrier into the coronary sinus, and to assume a straighter second configuration when biased toward the straighter configuration, said carrier having a lumen extending lengthwise therethrough; and    an elongated rod of a material less flexible than said carrier and adapted to be received by the lumen in said carrier;    whereby to urge said carrier from the first configuration to the second configuration, to straighten a natural curvature of at least a portion of the coronary sinus in the vicinity of the posterior leaflet of the mitral valve, to move the posterior annulus anteriorly and thereby improve leaflet coaptation and reduce mitral regurgitation.    
   
   
       2 . An assembly according to  claim 1  wherein said carrier is of a circular cross-section in at least a portion thereof.  
   
   
       3 . An assembly according to  claim 1  wherein said carrier is of an ovoid cross-section in at least a portion thereof.  
   
   
       4 . An assembly according to  claim 1  wherein said rod is provided with varying degrees of stiffness along the length thereof.  
   
   
       5 . An assembly according to  claim 1  wherein said rod is selected from a kit comprising a plurality of rods having different degrees of stiffness.  
   
   
       6 . An assembly according to  claim 1  wherein said rod is selected from a kit comprising a plurality of rods having different lengths.  
   
   
       7 . An assembly according to  claim 1  wherein the assembly further comprises a guidewire, and said carrier further comprises an opening through which said guidewire is movable.  
   
   
       8 . An assembly according to  claim 1  wherein said carrier is provided with a second lumen extending lengthwise through said carrier; and 
 said assembly comprises a second elongated rod of a material less flexible than said carrier and adapted to be received by the second lumen;    whereby to further urge said carrier from the second configuration to a still straighter configuration.    
   
   
       9 . An assembly according to  claim 8  wherein the lumens are of different diameters.  
   
   
       10 . An assembly according to  claim 8  wherein said first rod is of a stiffness different from the stiffness of said second rod.  
   
   
       11 . An assembly according to  claim 8  wherein said rods are provided with varying degrees of stiffness along the length thereof.  
   
   
       12 . An assembly according to  claim 8  wherein said rod is selected from a kit comprising a plurality of rods having different lengths.  
   
   
       13 . An assembly according to  claim 11  wherein the stiffness of said first rod along at least a portion thereof is inversely coordinated with the stiffness of said second rod along at least a portion thereof.  
   
   
       14 . An assembly according to  claim 8  wherein the assembly further comprises a sheath for constraining said carrier, said sheath being removable from said carrier.  
   
   
       15 . An assembly according to  claim 14  wherein said sheath constrains said carrier in a first cross-sectional configuration and, upon removal of said sheath, frees said carrier to assume a second cross-sectional configuration.  
   
   
       16 . An assembly according to  claim 1  wherein said elongated rod is substantially straight in an unstressed condition.  
   
   
       17 . An assembly according to  claim 1  wherein said elongated rod is substantially curved after insertion into the coronary sinus.  
   
   
       18 . An assembly according to  claim 1  wherein said elongated rod comprises first and second end portions connected together by an intermediate portion, wherein said intermediate portion comprises first and second regions connected together by a central region, wherein said central region and said first and second end portions are substantially curved after said elongated body is inserted into the coronary sinus, and further wherein said first and second regions are substantially straight after the elongated body is inserted into the coronary sinus.  
   
   
       19 . An assembly according to  claim 18  wherein said central region, said first and second end portions and said first and second regions have a length such that said elongated body applies an anteriorly-directed force to the walls of the coronary sinus substantially adjacent to the posterior leaflet of the valve, and applies a posteriorly-directed force to the walls of the coronary sinus substantially adjacent to the commissures of the valve.  
   
   
       20 . An assembly according to  claim 1  wherein said elongated rod is formed at least in part out of a resilient material.  
   
   
       21 . An assembly according to  claim 20  wherein said elongated rod effects valve remodeling on a continuous basis over a prolonged period of time.  
   
   
       22 . An assembly according to  claim 21  wherein said elongated rod is formed at least in part out of a superelastic material.  
   
   
       23 . An assembly according to  claim 1  wherein said assembly further comprises a stabilizing scaffold engaging to said elongated carrier.  
   
   
       24 . An assembly according to  claim 1  wherein at least a portion of said elongated carrier is configured to facilitate tissue in-growth.  
   
   
       25 . An assembly for reducing mitral regurgitation, the assembly comprising: 
 an elongated carrier of material sufficiently flexible to assume a first configuration generally conforming to a coronary sinus upon insertion of said carrier into the coronary sinus, and to assume a straighter second configuration when biased toward the straighter configuration, said carrier having a plurality of lumens extending lengthwise therethrough; and    a plurality of elongated rods of a material less flexible than said carrier and adapted to be received by the lumens in said carrier;    whereby to urge said carrier from the first configuration to the second configuration, to straighten a natural curvature of at least a portion of the coronary sinus in the vicinity of the posterior leaflet of the mitral valve, to move the posterior annulus anteriorly and thereby improve leaflet coaptation and reduce mitral regurgitation.    
   
   
       26 . A method for reducing mitral regurgitation, the method comprising the steps of: 
 providing a flexible carrier having at least one lumen extending lengthwise therethrough;    advancing a guidewire through the vascular system of a patient until a distal end of the guidewire is disposed in the coronary sinus of the patient;    advancing the carrier over the guidewire until a distal end of the carrier is disposed in the coronary sinus;    advancing a rod of a selected stiffness into said at least one lumen to exert a straightening force on the carrier and thereby on the coronary sinus to move the annulus of the mitral valve anteriorly, whereby to reduce mitral regurgitation.    
   
   
       27 . A method according to  claim 26  wherein said carrier comprises a plurality of lumens extending lengthwise therethrough, and further wherein said guidewire extends through one of said lumens.  
   
   
       28 . A method according to  claim 26  wherein the flexible carrier is provided in a sheath, the sheath and carrier are advanced together, and the sheath is removed after the carrier is disposed in the coronary sinus and before the advancement of the rod into the carrier.  
   
   
       29 . An assembly for reducing mitral regurgitation, the assembly comprising: 
 a carrier of material sufficiently flexible to assume a first configuration generally conforming to a coronary sinus upon insertion of said carrier into the coronary sinus, and to assume a straighter second configuration when biased toward the straighter configuration, said carrier having a plurality of first lumens extending lengthwise therethrough;    a catheter shaft having a plurality of first lumens extending lengthwise therethrough, each alignable with one of the carrier first lumens, a distal end of said catheter shaft being engageable with a proximal end of said carrier;    a plurality of straightening rods, each less flexible than said carrier and adapted to be received by the catheter shaft first lumens and by the carrier first lumens; and    a push rod adapted to be received by at least the catheter shaft first lumens and engageable with one of said straightening rods and operable to push the one straightening rod into one of the carrier first lumens in alignment with the catheter shaft lumen in which said push rod is disposed;    whereby to bias the carrier from the first configuration to the second configuration.    
   
   
       30 . An assembly according to  claim 29  wherein said straightening rods are of varying degrees of stiffness along the length thereof.  
   
   
       31 . An assembly according to  claim 29  wherein said rod is selected from a kit comprising a plurality of rods having different lengths.  
   
   
       32 . An assembly according to  claim 29  wherein the assembly further comprises a guidewire adapted for insertion into the coronary sinus, and said carrier and said catheter shaft are movable along said guidewire.  
   
   
       33 . An assembly according to  claim 29  wherein said push rod is adapted to connect to a selected straightening rod end-to-end, and to be disconnected therefrom.  
   
   
       34 . An assembly according to  claim 29  wherein said carrier and said catheter shaft are each provided with second lumens of smaller diameter than the first lumens.  
   
   
       35 . An assembly according to  claim 34  wherein tether lines are fixed in the carrier second lumens, and extend proximally from a proximal end of said catheter shaft, the tether lines being drawable through said catheter shaft to urge said catheter shaft and said carrier into abutting relationship.  
   
   
       36 . An assembly for reducing mitral regurgitation, the assembly comprising: 
 an elongated carrier of material sufficiently flexible to assume a first configuration generally conforming to a coronary sinus upon insertion of said carrier into the coronary sinus, and to assume a straighter second configuration when biased toward the straighter configuration, said carrier having a plurality of first lumens extending lengthwise therethrough and a plurality of second lumens, smaller in diameter than the first lumens, extending therethrough;    a catheter shaft having a plurality of first and second lumens extending lengthwise therethrough and alignable with the respective first and second lumens of said carrier, a distal end of said catheter shaft being engageable with a proximal end of said carrier;    a plurality of straightening rods less flexible than said carrier and adapted to be received by the catheter shaft first lumens and by the carrier first lumens;    a plurality of push rods adapted to be received by at least the catheter shaft first lumens; and    a tether fixed in at least one carrier second lumen and extending through the catheter shaft second lumen and manipulatable to draw said carrier into abutting engagement with said catheter shaft;    wherein at least one selected stiffening rod is insertable into at least one selected catheter shaft first lumen, and at least one push rod is insertable into the selected catheter shaft lumen and into engagement with the selected stiffening rod to push the selected stiffening rod into one of the carrier first lumens, to bias the carrier from the first configuration towards the second configuration.    
   
   
       37 . A method for reducing mitral regurgitation, the method comprising the steps of: 
 inserting a guidewire into a patient's vascular system and into the coronary sinus;    loading a carrier onto the guidewire, the carrier being of a material sufficiently flexible to assume a first configuration generally conforming to the coronary sinus, the carrier having a plurality of first lumens extending lengthwise therethrough;    loading a catheter shaft onto the guidewire, the catheter shaft having a plurality of first lumens extending lengthwise therethrough and alignable with the carrier first lumens;    advancing the catheter shaft and the carrier distally along the guidewire until the carrier is disposed in the coronary sinus and adjacent the posterior leaflet of the mitral valve;    loading a straightening rod into a selected one of the catheter shaft first lumens, the straightening rod being of a material less flexible than the lumen;    loading a push rod into the catheter shaft selected first lumen;    engaging the straightening rod with the push rod and advancing the push rod distally to push the straightening rod distally into one of the carrier first lumens aligned with the selected catheter shaft first lumen to advance the engaged straightening rod into the carrier first lumen, to cause the carrier to assume a straighter second configuration;    whereby to apply an anteriorly-directed force to the posterior leaflet of the mitral valve, thereby to reduce mitral regurgitation.    
   
   
       38 . A method according to  claim 37  wherein the push rod is connected to the straightening rod end-to-end when engaging the straightening rod, and is disconnected from the straightening rod upon completion of the pushing of the straightening rod.  
   
   
       39 . A method according to  claim 37  wherein the straightening rod and the push rod are releasably connected to each other.  
   
   
       40 . A method for reducing mitral regurgitation, the method comprising the steps of: 
 providing a flexible carrier having at least one lumen extending lengthwise therethrough;    advancing a guidewire through the vascular system of a patient until a distal end of the guidewire is disposed in the coronary sinus of the patient;    advancing the carrier over the guidewire until a distal end of the carrier is disposed in the coronary sinus;    advancing a rod of a selected stiffness into said at least one lumen to exert a straightening force on the carrier and thereby on the coronary sinus to move the annulus of the mitral valve anteriorly, whereby to reduce mitral regurgitation;    positioning the proximal end of said flexible carrier in a tissue pocket.    
   
   
       41 . A method according to  claim 40  further comprising: 
 capping the proximal end of said flexible carrier before positioning it in the tissue pocket.    
   
   
       42 . A method according to  claim 40  further comprising: 
 cutting said flexible carrier to length and capping the proximal end of said flexible carrier before positioning it in the tissue pocket.    
   
   
       43 . A method according to  claim 42  further comprising: 
 positioning a bumper into at least one lumen after advancing said lumen and before capping said proximal end of said flexible carrier.    
   
   
       44 . A method for reducing mitral regurgitation, the method comprising the steps of: 
 providing a flexible carrier having at least one lumen extending lengthwise therethrough;    advancing a guidewire through the vascular system of a patient until a distal end of the guidewire is disposed in the coronary sinus of the patient;    advancing the carrier over the guidewire until a distal end of the carrier is disposed in the coronary sinus;    advancing a rod of a selected stiffness into said at least one lumen to exert a straightening force on the carrier and thereby on the coronary sinus to move the annulus of the mitral valve anteriorly, whereby to reduce mitral regurgitation;    cutting said flexible carrier to length;    positioning a bumper into at least one lumen;    capping the proximal end of said flexible carrier;    positioning the proximal end of said flexible carrier in a tissue pocket.    
   
   
       45 . A method according to  claim 44  further comprising: 
 uncapping the proximal end of said flexible carrier;    removing the bumper from the at least one lumen;    removing the rod from said at least one lumen;    advancing a different rod into said at least one lumen to exert a straightening force on the carrier and thereby on the coronary sinus to move the annulus of the mitral valve anteriorly, whereby to reduce mitral regurgitation;    positioning a bumper into at least one lumen;    capping the proximal end of said flexible carrier;    positioning the proximal end of said flexible carrier in a tissue pocket.    
   
   
       46 . A method according to  claim 44  further comprising: 
 uncapping the proximal end of said flexible carrier;    removing the bumper from the at least one lumen;    removing the rod from said at least one lumen;    removing the flexible carrier from the coronary sinus of the patient.