Stent structures for use with valve replacements

Abstract

The present embodiments provide a medical device for implantation in a patient comprising a stent and a valve. The stent comprises a proximal region comprising a cylindrical shape having a first outer diameter in an expanded state, and a distal region comprising a cylindrical shape having a second outer diameter in the expanded state. The second outer diameter is greater than the first outer diameter. A proximal region of the valve is at least partially positioned within the proximal region of the stent, and the distal region of the valve is at least partially positioned within one of tapered and distal regions of the stent. When implanted, the proximal region of the stent and the proximal region of the valve are aligned with a native valve, and the distal region of the valve is distally spaced-apart from the native valve.

1 . A medical device for implantation in a patient, the medical device comprising:
 a stent comprising:
 a proximal region comprising a cylindrical shape having a first outer diameter when the stent is in an expanded state; 
 a distal region comprising a cylindrical shape having a second outer diameter when the stent is in the expanded state, where the second outer diameter is greater than the first outer diameter; 
 a tapered region disposed between the proximal and distal regions, where the tapered region transitions the stent from the first diameter to the second diameter; and 
   a valve coupled to at least a portion of the stent, the valve having proximal and distal regions, where the proximal region of the valve is at least partially positioned within the proximal region of the stent and the distal region of the valve is at least partially positioned within one of the tapered and distal regions of the stent.   
     
     
         2 . The medical device of  claim 1  where, when implanted, the proximal region of the stent and the proximal region of the valve are aligned with a native valve, and the distal region of the valve is distally spaced-apart from the native valve. 
     
     
         3 . The medical device of  claim 1  further comprising a plurality of closed cells disposed around the perimeter of the proximal region of the stent, and another plurality of closed cells disposed around the perimeter of the distal region of the stent. 
     
     
         4 . The medical device of  claim 3  where the tapered region further comprises a plurality of closed cells, where an overall length of each of the closed cells of the tapered region is greater than an overall length of each of the closed cells of the proximal region of the stent and less than an overall length of each of the closed cells of the distal region of the sent when the stent is in the expanded state. 
     
     
         5 . The medical device of  claim 3  where the plurality of closed cells of the proximal region of the stent comprise a higher radial force relative to the plurality of closed cells of the distal region of the stent when the stent is in the expanded state. 
     
     
         6 . The medical device of  claim 3  where at least one of the closed cells of the distal region of the stent comprises four angled strut segments, and where two of the angled strut segments comprise a greater length relative to the other two angled strut segments within the closed cell. 
     
     
         7 . The medical device of  claim 1  where the proximal region of the valve comprises a cylindrical body, and the distal region of the valve has a generally rectangular shape comprising opposing flat surfaces that are separated by narrower flat sides, where the opposing flat surfaces at the distal end of the valve allow fluid flow therethrough during antegrade flow and are generally adjacent to one another to inhibit blood flow through the valve during retrograde flow. 
     
     
         8 . The medical device of  claim 1  where the proximal region of the stent comprises a plurality of proximal apices, where at least one of the proximal apices has an end region having an integral barb formed therein, where the plurality of closed cells of the proximal region are disposed distal to the plurality of proximal apices. 
     
     
         9 . A medical device for implantation in a patient, the medical device comprising:
 a stent having proximal and distal regions, and further comprising delivery and expanded states;   a plurality of closed cells disposed at various locations between the proximal and distal regions of the stent,   where each closed cell has an overall length, when the stent is in the expanded state, that is greater than a length of every other closed cell that is disposed proximally thereof; and   a valve coupled to at least the proximal region of the stent.   
     
     
         10 . The medical device of  claim 9 , where the stent comprises at least three longitudinal regions in which a plurality of closed cells are disposed around a perimeter of the stent, where the first longitudinal region is disposed proximal to the second longitudinal region, and the second longitudinal region is disposed proximal to the third longitudinal region,
 where an overall length of each of the closed cells of the first longitudinal region is less than an overall length of each of the closed cells of the second longitudinal region, and where the overall length of each of the closed cells of the second longitudinal region is less than an overall length of each of the closed cells of the third longitudinal region.   
     
     
         11 . The medical device of  claim 9  where a plurality of closed cells disposed around a perimeter of the proximal region of the stent comprise a higher radial force relative to a plurality of closed cells disposed around a perimeter of the distal region of the stent. 
     
     
         12 . The medical device of  claim 9  where at least one of the closed cells comprises four angled strut segments, and where two of the angled strut segments comprise a greater length relative to the other two angled strut segments within the closed cell. 
     
     
         13 . The medical device of  claim 9  where at least one of the closed cells comprises four angled strut segments, and where two of the angled strut segments comprise a first width, which is greater than a second width of the other two angled strut segments within the closed cell. 
     
     
         14 . The medical device of  claim 9  where the proximal region of the stent comprises a cylindrical shape having a first outer diameter when the stent is in the expanded state, and where the distal region of the stent comprises a cylindrical shape having a second outer diameter when the stent is in the expanded state, where the second outer diameter is greater than the first outer diameter, the stent further comprising:
 a tapered region disposed between the proximal and distal regions, where the tapered region transitions the stent from the first outer diameter to the second outer diameter. 
 
     
     
         15 . A medical device for implantation in a patient, the medical device comprising:
 a stent comprising:
 a proximal region comprising a cylindrical shape having a first outer diameter when the stent is in an expanded state; 
 a distal region comprising a cylindrical shape having a second outer diameter when the stent is in the expanded state, where the second outer diameter is greater than the first outer diameter; 
 a tapered region disposed between the proximal and distal regions, where the tapered region transitions the stent from the first diameter to the second diameter; and 
   a valve having proximal and distal regions, where the proximal region of the valve is positioned at least partially within the proximal region of the stent, and where at least a portion of the valve is mechanically coupled to one of the tapered and distal regions of the stent.   
     
     
         16 . The medical device of  claim 15  where an overall length of each of a plurality of closed cells of the proximal region of the stent is less than an overall length of each of a plurality of closed cells of the distal region of the stent when the stent is in the expanded state. 
     
     
         17 . The medical device of  claim 16  where the tapered region of the stent further comprises plurality of closed cells, where an overall length of each of the closed cells of the tapered region is greater than the overall length of each of the closed cells of the proximal region of the stent and less than an overall length of each of the closed cells of the distal region of the stent. 
     
     
         18 . The medical device of  claim 16  where at least one of the closed cells of the proximal region of the stent comprises four angled strut segments, and where two of the angled strut segments comprise a greater length relative to the other two angled strut segments within the closed cell. 
     
     
         19 . The medical device of  claim 16  where at least one of the closed cells of the proximal region of the stent comprises four angled strut segments, where two of the angled strut segments comprise a first width, which is greater than a second width of the other two angled strut segments within the closed cell. 
     
     
         20 . The medical device of  claim 15  where the proximal region of the stent comprises a plurality of proximal apices, where at least one of the proximal apices has an end region having an integral barb formed therein, where the plurality of closed cells of the proximal region of the stent are disposed distal to the plurality of proximal apices.