Bifurcated medical device for treating a target site and associated method

Abstract

Embodiments of the present invention provide medical devices and methods for treating a target site within the body. For example, one embodiment provides a stent graft for treating a target site proximate to a bifurcated lumen, wherein the stent graft includes a first tubular structure having proximal and distal ends and a side wall extending therebetween. The first tubular structure includes an opening defined within the side wall and is configured to define a first portion having first and second ends and a second portion having first and second ends. The opening corresponds to the first ends of the first and second portions and the second ends of the first and second portions respectively correspond to the proximal and distal ends of the first tubular structure, and at least a portion of the first and second portions are configured to be positioned within respective branches of a bifurcated lumen.

1 . A stent graft for treating a target site proximate to a bifurcated lumen, the stent graft comprising:
 a first tubular structure having proximal and distal ends and a side wall extending therebetween, the first tubular structure comprising an opening defined within the side wall, wherein the first tubular structure is configured to define a first portion having first and second ends and a second portion having first and second ends, wherein the opening corresponds to the first ends of the first and second portions and the second ends of the first and second portions respectively correspond to the proximal and distal ends of the first tubular structure and at least a portion of the first and second portions are configured to be positioned within respective branches of a bifurcated lumen, wherein the first tubular structure comprises an expanded preset configuration, and wherein the first tubular structure is configured to be constrained to a smaller diameter than the expanded preset configuration and return to the expanded preset configuration when unconstrained.   
     
     
         2 . The stent graft of  claim 1 , wherein the first tubular structure comprises at least one layer of an occlusive material. 
     
     
         3 . The stent graft of  claim 1 , wherein the first tubular structure comprises at least one layer of braided strands. 
     
     
         4 . The stent graft of  claim 3 , wherein the first tubular structure comprises braided strands of an elastic metallic alloy. 
     
     
         5 . The stent graft of  claim 3 , wherein the opening is defined by displacing the braided strands within the side wall of the first tubular structure. 
     
     
         6 . The stent graft of  claim 1 , wherein the first ends of the first and second portions are D-shaped in cross section such that the first ends of the first and second portions are configured to cooperate to define a substantially circular opening. 
     
     
         7 . The stent graft of  claim 1 , wherein the first tubular structure comprises a bulbous region between its proximal and distal ends, and wherein the opening is defined in the bulbous region. 
     
     
         8 . The stent graft of  claim 1 , wherein the first tubular structure is configured to be shaped along the opening such that the first and second portions comprise respective lumens extending between the first and second ends of the first and second portions that are not in fluid communication with one another. 
     
     
         9 . The stent graft of  claim 1 , wherein the opening comprises a cut extending partially about the circumference of the first tubular structure such that the first tubular structure is configured to be folded along the cut to form the first and second portions. 
     
     
         10 . The stent graft of  claim 1 , wherein the first ends of the first and second tubular portions comprise at least one radiopaque marker. 
     
     
         11 . The stent graft of  claim 1 , wherein at least a portion of an outer surface of the first and second portions comprises a corrugated surface. 
     
     
         12 . The stent graft of  claim 1 , wherein the first ends of the first and second portions are configured to engage a lumen upstream of an aneurysm such that the opening substantially conforms to a diameter of the lumen. 
     
     
         13 . The stent graft of  claim 12 , wherein the second ends of the first and second portions are configured to engage respective branches of the bifurcated lumen downstream of the aneurysm. 
     
     
         14 . The stent graft of  claim 12 , further comprising at least one hook located proximate to each of the first ends of the first and second portions and configured to engage the lumen. 
     
     
         15 . The stent graft of  claim 1 , wherein the first and second portions are configured to be coaxially aligned for delivery within a catheter. 
     
     
         16 . The stent graft of  claim 1 , further comprising a second tubular structure having proximal and distal ends and a lumen extending therebetween and configured to engage the first tubular structure, wherein the proximal end of the second tubular structure comprises a pair of openings configured to receive the first tubular structure and align the lumen of the second tubular structure with the opening defined in the first tubular structure. 
     
     
         17 . The stent graft of  claim 16 , wherein the second tubular structure comprises an expanded preset configuration, and wherein the second tubular structure is configured to be constrained to a smaller diameter than the expanded preset configuration and return to the expanded preset configuration when unconstrained. 
     
     
         18 . The stent graft of  claim 16 , wherein the second tubular structure further comprises a clamp configured to clamp the proximal end thereof so as to define the pair of openings. 
     
     
         19 . The stent graft of  claim 16 , wherein the first and second tubular portions are configured to be delivered to the bifurcated lumen in axial alignment with one another. 
     
     
         20 . The stent graft of  claim 1 , wherein the opening is defined approximately midway between the proximal and distal ends of the first tubular structure. 
     
     
         21 . A method for treating a target site proximate to a bifurcated lumen, the method comprising:
 constraining a first tubular structure to a smaller diameter than an expanded preset configuration, wherein the first tubular structure has a proximal end and a distal end and an opening defined within a sidewall of the first tubular structure;   delivering the first tubular structure to the bifurcated lumen; and   deploying the first tubular structure within the bifurcated lumen such that the first tubular structure self expands from the constrained smaller diameter, wherein deploying comprises shaping the first tubular structure proximate to the opening such that at least a portion of the first and second portions of the first tubular structure extend within respective branches of the bifurcated lumen and such that the opening is configured to direct fluid into each of the first and second portions.   
     
     
         22 . The method of  claim 21 , wherein deploying comprises deploying the first tubular structure such that the first tubular structure engages the bifurcated lumen upstream and downstream of an aneurysm. 
     
     
         23 . The method of  claim 21 , wherein delivering comprises delivering the first tubular structure over at least one guide wire. 
     
     
         24 . The method of  claim 21 , wherein constraining comprises elongating the first tubular structure to a smaller diameter. 
     
     
         25 . The method of  claim 21 , wherein deploying comprises deploying the first tubular structure such that first ends of the first and second portions engage the bifurcated lumen upstream of an aneurysm and the respective branches of the bifurcated lumen and such that the opening substantially conforms to a diameter of the bifurcated lumen. 
     
     
         26 . The method of  claim 25 , wherein deploying comprises deploying the first tubular structure such that second ends of the first and second portions that respectively correspond to the proximal and distal ends of the first tubular structure are configured to engage respective branches of the bifurcated lumen downstream of the aneurysm. 
     
     
         27 . The method of  claim 21 , wherein delivering comprises delivering the first and second portions in coaxial alignment with one another. 
     
     
         28 . The method of  claim 21 , further comprising deploying a second tubular structure having a lumen such that a pair of openings defined in the proximal end of the second tubular structure are configured to receive the first tubular structure and align the lumen of the second tubular structure with the opening defined in the first tubular structure. 
     
     
         29 . The method of  claim 28 , wherein deploying the second tubular structure comprises deploying a distal end of the second tubular structure in a lumen upstream of an aneurysm and a proximal end of the second tubular structure in the lumen downstream of the aneurysm. 
     
     
         30 . The method of  claim 21 , wherein deploying comprises folding the first and second portions along the opening defined approximately midway between the proximal and distal ends of the first tubular structure. 
     
     
         31 . The method of  claim 21 , wherein deploying comprises engaging a distal end of the first or second portion, and wherein shaping comprises inverting the first and second portions with respect to one another while engaging the distal end of the first or second portion. 
     
     
         32 . A method for fabricating a stent graft comprising:
 braiding a first tubular structure about a mandrel, the first tubular structure having a proximal end and a distal end and a sidewall extending therebetween;   shaping the first tubular structure so as to form first and second portions each having first and second ends, wherein at least a portion of the first and second portions are configured to extend within respective branches of a bifurcated lumen;   defining an opening within the sidewall, wherein the opening is configured to correspond to the first ends of the first and second portions; and   heat setting the first tubular structure while the first tubular structure is shaped.   
     
     
         33 . The method of  claim 32 , wherein braiding comprises braiding the first tubular structure into at least one layer with a plurality of strands. 
     
     
         34 . The method of  claim 32 , wherein shaping comprises folding the first tubular structure along the opening. 
     
     
         35 . The method of  claim 32 , wherein defining comprises forming a cut partially about the circumference of the first tubular structure, and wherein shaping comprises folding the first tubular structure along the cut. 
     
     
         36 . The method of  claim 32 , wherein defining comprises displacing braided strands of the first tubular structure to define the opening. 
     
     
         37 . The method of  claim 32 , wherein heat setting comprises heat setting the first tubular structure about a pair of D-shaped pins to define the opening. 
     
     
         38 . The method of  claim 32 , wherein shaping comprises shaping the first tubular structure along the opening such that the first and second portions comprise respective lumens extending between the proximal and distal ends of the first and second portions that are not in fluid communication with one another. 
     
     
         39 . The method of  claim 32 , further comprising braiding a second tubular structure on a mandrel, the second tubular structure comprising a proximal end and a distal end and lumen extending therebetween. 
     
     
         40 . The method of  claim 39 , further comprising defining a pair of openings in the second tubular structure configured to receive the first tubular structure and align the lumen of the second tubular structure with the opening defined in the first tubular structure. 
     
     
         41 . The method of  claim 40 , wherein defining the pair of openings comprises clamping the proximal end of the second tubular structure to define the pair of openings.