Apparatus and methods for delivering a stent into an ostium

Abstract

Apparatus and methods are provided for delivering a stent into an ostium. The apparatus includes a catheter including a proximal end, a distal end, and proximal and distal balloons disposed adjacent one another on the distal end. The balloons are expandable independently of one another, and a stent is provided surrounding the balloons. During use, the distal end of the catheter is introduced into a main lumen, and the proximal balloon is inflated to flare a proximal portion of the stent. The distal end is then advanced into the ostium until the flared proximal portion contacts a wall of the main lumen surrounding the ostium. The distal balloon is inflated to expand a distal portion of the stent, e.g., to dilate a lesion within the branch and/or ostium. Thereafter, the balloons are collapsed, and the apparatus is withdrawn, leaving the stent within the ostium.

1 . An apparatus for delivering a prosthesis into an ostium of a body lumen, comprising:
 an elongate member comprising a proximal end, a distal end sized for introduction into a body lumen, and first and second lumens extending between the proximal and distal ends, thereby defining a longitudinal axis;   a first expandable member on the distal end of the elongate member, the first expandable member comprising an interior communicating with the first lumen;   a second expandable member on the distal end of the elongate member, the second expandable member comprising an interior communicating with the second lumen; and   a prosthesis comprising a first portion surrounding the first expandable member and a second portion surrounding the second expandable member;   the second expandable member being expandable independently of the first expandable member for expanding the second portion to an enlarged condition while the first portion remains in a contracted condition, the first expandable member being expandable for expanding the first portion to an enlarged condition that is smaller than the second portion in its enlarged condition.   
     
     
         2 . The apparatus of  claim 1 , further comprising a constraint for maintaining the first portion in the contracted condition while the second expandable member is expanded. 
     
     
         3 . The apparatus of  claim 2 , wherein the constraint comprises a tubular member overlying the first portion, the tubular member being movable between a first position covering the first portion and a second position uncovering the first portion. 
     
     
         4 . The apparatus of  claim 3 , wherein the tubular member is movable between a third position covering the second portion and the first position. 
     
     
         5 . The apparatus of  claim 1 , wherein the second expandable member comprises a transverse surface when expanded that is disposed adjacent the first expandable member, the second portion being deformed transversely by the transverse surface as the second expandable member is expanded such that the second portion extends transversely relative to the longitudinal axis when the second portion expands to its enlarged condition. 
     
     
         6 . The apparatus of  claim 5 , wherein the transverse surface has a generally concave shape when the second expandable member is expanded. 
     
     
         7 . The apparatus of  claim 6 , wherein the first expandable member comprises a tapered portion that at least partially nests within the concave shape of the transverse surface as the first expandable member is expanded. 
     
     
         8 . The apparatus of  claim 6 , wherein the second portion at least partially contacts the transverse surface of the second expandable member when the second expandable member is expanded such that an acute angle is defined between the first and second portions. 
     
     
         9 . The apparatus of  claim 1 , wherein the first portion has a first length and the second portion has a second length, the second length being shorter than the first length. 
     
     
         10 . The apparatus of  claim 9 , wherein the first expandable member has a length at least as long as the first length. 
     
     
         11 . The apparatus of  claim 1 , wherein the second expandable member is disposed proximal to the first expandable member on the elongate member distal end. 
     
     
         12 . The apparatus of  claim 1 , wherein the second expandable member is disposed immediately adjacent the first expandable member such that adjacent surfaces of the first and second expandable members contact one another as the first and second expandable members are expanded. 
     
     
         13 . The apparatus of  claim 1 , wherein the second expandable member at least partially overlaps the first expandable member, thereby preventing gaps from forming between the first and second expandable members when the second expandable member is expanded to its enlarged condition. 
     
     
         14 . The apparatus of  claim 13 , wherein a portion of the second expandable member is attached to a portion of the first expandable member. 
     
     
         15 . The apparatus of  claim 14 , wherein a distal end of the second expandable member extends over and is attached to a distal end of the first expandable member. 
     
     
         16 . The apparatus of  claim 1 , wherein the elongate member comprises a port on the proximal end and a valve for selectively connecting at least one of the first and second lumens to the port. 
     
     
         17 . The apparatus of  claim 16 , wherein the valve is movable to a position wherein both of the first and second lumens are connected to the port such that the first and second expandable members may be expanded or collapsed substantially simultaneously. 
     
     
         18 . An apparatus for delivering a prosthesis into an ostium of a body lumen, comprising:
 an elongate member comprising a proximal end, a distal end sized for introduction into a body lumen, and a longitudinal axis extending therebetween;   a first expandable member on the distal end of the elongate member, the first expandable member being expandable from a proximal end of the elongate member, the first expandable member comprising a length for receiving a first portion of a tubular prosthesis thereon; and   a second expandable member on the distal end of the elongate member adjacent the first expandable member, a portion of the second expandable member being attached to the first expandable member, the second expandable member being expandable from a proximal end of the elongate member independently of the first expandable member for expanding the second portion to an enlarged condition while the first portion remains in a contracted condition, such that, in an enlarged condition, the second expandable member defines a transverse surface adjacent the first expandable member for expanding a second portion of the prosthesis to a flared condition to facilitate placement of the prosthesis within an ostium.   
     
     
         19 . The apparatus of  claim 18 , further comprising a prosthesis comprising a first portion surrounding the first expandable member and a second portion surrounding the second expandable member. 
     
     
         20 . A method for implanting a prosthesis within an ostium extending from a main lumen into a branch lumen using an elongate member comprising first and second expandable members on a distal end of the elongate member, the prosthesis comprising first and second portions surrounding the first and second expandable members, respectively, the method comprising:
 directing the distal end of the elongate member into the main lumen;   expanding the second expandable member to cause the second portion of the prosthesis to expand transversely;   directing the distal end into the ostium until the expanded second portion contacts a wall of the main lumen surrounding the ostium and the first portion is disposed within the branch lumen;   expanding the first expandable member to expand the first portion of the prosthesis to contact a wall of the branch lien;   collapsing the first and second expandable members; and   withdrawing the elongate member from the branch and main lumens, leaving the prosthesis with the first portion expanded within the branch lumen and the second portion contacting the wall of the main lumen surrounding the ostium.