Method and device for inserting and withdrawing a two piece stent across a constricting anatomic structure

Abstract

A stent device and methods for inserting and removing a stent to and from an anatomical tract of a living being. The stent includes a distal segment and a proximal segment joined by a flexible connection structure. The stent is inserted using components comprising a delivery assembly such that the stent proceeds through the anatomical tract and seats the flexible connection structure of the stent in a natural constricting structure of the anatomical tract. The flexible quality of the connection structure permits the natural constricting functions of the anatomical tract to occur. The natural closure of the anatomical constricting structure stops the flow of fluid, for example, from a target organ which indicates that the stent is properly placed within the anatomical tract.

What is claimed is:  
     
         1 . A method of placing a prosthesis into an anatomical tract that passes through an anatomical constricting structure, the prosthesis comprising a first segment, a second segment and a connection structure that flexibly connects the first and second segments, the prosthesis mounted on an insertion assembly, the method comprising: 
 inserting the prosthesis and the insertion assembly into an opening in the anatomical tract;    advancing the prosthesis through the anatomical tract using the insertion assembly until at least the first segment is at least partially located on a far side of the anatomical constricting structure from the opening in the anatomical tract;    at least partially withdrawing at least a first portion of the insertion assembly from the anatomical tract relative to the prosthesis; and    manipulating at least one of a second portion of the insertion assembly and a portion of the prosthesis to obtain the connection structure extending through the anatomical constricting structure, the first segment being located entirely on the far side of the anatomical constricting structure, and the second segment being located entirely on a near side of the anatomical constricting structure relative to the opening in the anatomical tract.    
     
     
         2 . The method of  claim 1 , wherein advancing the prosthesis through the anatomical tract using the insertion assembly comprises locating at least one of the first and second segments relative to at least one of an organ and a cavity associated with the anatomical tract.  
     
     
         3 . The method of  claim 2 , wherein locating at least one of the first and second segments relative to at least one of an organ and a cavity comprises locating the first segment relative to an opening in a bladder.  
     
     
         4 . The method of  claim 1 , wherein: 
 the first segment comprises a first end connected to the connection structure and a second end opposite the first end, the second end having an opening; and    locating the first segment relative to the opening in the bladder comprises advancing the second end of the first segment through the opening in the bladder and into the bladder such that at least one of liquids and gases are released into the bladder signaling entry of the first segment into the bladder.    
     
     
         5 . The method of  claim 1 , wherein: 
 locating the first segment entirely on the far side of the anatomical constricting structure, and locating the second segment entirely on a near side of the anatomical constricting structure relative to the opening in the anatomical tract signals placement of the connecting structure within the anatomical constricting structure by voluntary control of the anatomical constricting structure.    
     
     
         6 . The method of  claim 3 , wherein: 
 the first segment comprises a first end connected to the connection structure and a second end opposite the first end, the second end having an opening; and    locating the first segment relative to the opening in the bladder comprises advancing the second end of the first segment through the opening in the bladder and into the bladder such that fluid held in the bladder can flow through the opening of the second end and into the first segment.    
     
     
         7 . The method of  claim 6 , wherein: 
 the insertion assembly comprises: 
 a mandrel,  
 a pusher mountable on the mandrel, and  
 a removal structure attached to one of the first and second segments; and  
   at least partially withdrawing at least a portion of the insertion assembly from the anatomical tract comprises removing the mandrel and the pusher from the anatomical constricting structure.    
     
     
         8 . The method of  claim 7 , wherein locating the first segment relative to the at least one of an organ and a cavity comprises locating the first segment entirely on the far side of the anatomical constricting structure.  
     
     
         9 . The method of  claim 8 , wherein manipulating one of the second portion of the insertion assembly and a portion of the prosthesis comprises pulling on at least a portion of the removal structure until the connection structure extends through the anatomical constricting structure and the second segment is entirely on the near side.  
     
     
         10 . The method of  claim 2 , wherein locating at least one of the first and second segments relative to at least one of the organ and the cavity comprises advancing the first segment entirely through the anatomical constricting structure and advancing the second segment at most partially through the anatomical constricting structure.  
     
     
         11 . The method of  claim 10 , wherein: 
 the insertion assembly comprises: 
 a mandrel;  
 a pusher mountable on the mandrel;  
 a removal structure attached to one of the first and second segments; and  
   at least partially withdrawing at least a portion of the insertion assembly from the anatomical tract comprises removing the mandrel and the pusher from the anatomical constricting structure.    
     
     
         12 . The method of  claim 11 , wherein manipulating one of the second portion of the insertion assembly and a portion of the prosthesis comprises pulling on at least a portion of the removal structure until the connection structure extends through the anatomical constricting structure and the second segment is on the near side.  
     
     
         13 . The method of  claim 10 , wherein manipulating one of the second portion of the insertion assembly and a portion of the prosthesis comprises pulling the one of the second portion of the insertion assembly and a portion of the prosthesis to withdraw the second segment to the near side such that the connection structure extends through the anatomical constricting structure.  
     
     
         14 . The method of  claim 13 , wherein pulling the one of the second portion of the insertion-assembly and a portion of the prosthesis comprises pulling at least a portion of a removal structure, the pulled portion of the removal structure attached to at least the second segment.  
     
     
         15 . The method of  claim 14 , wherein the pulled portion of the removal structure includes at least a removal thread attached to the second segment.  
     
     
         16 . The method of  claim 13 , wherein: 
 the insertion assembly comprises: 
 a mandrel,  
 a pusher mountable on the mandrel, and  
 a removal structure attached to one of the first and second segments; and  
   at least partially withdrawing at least a portion of the insertion assembly from the anatomical tract comprises removing the mandrel and the pusher from the anatomical constricting structure.    
     
     
         17 . The method of  claim 16 , wherein pulling the second portion of the insertion assembly comprises pulling at least a portion of the removal structure that is attached to the second segment.  
     
     
         18 . The method of  claim 13 , wherein: 
 the insertion assembly comprises: 
 a stiff member that extends through the first and second segments and the connection structure and that contacts an end of the first segment that is opposite an end of the first segment connected to the connection structure,  
 an insertion structure that extends through the second segment and the connection structure and into the first segment,  
 at least one segment release structure, each segment release structure releasably connecting the insertion structure to one of the first and second segments, and  
 a removal structure attached to at least the second segment; and  
   pulling at least one of the second portion of the insertion assembly and the portion of the prosthesis comprises pulling the insertion structure.    
     
     
         19 . The method of  claim 18 , wherein: 
 the at least one segment release structure comprises a first segment release structure that releasably connects the insertion structure to the first segment; and    withdrawing at least a portion of the insertion assembly comprises withdrawing the first segment release structure to release the first segment from the insertion structure before pulling the insertion structure.    
     
     
         20 . The method of  claim 18 , wherein withdrawing at least a portion of the insertion assembly further comprises at least partially withdrawing the stiff member from the prosthesis before pulling the insertion structure.  
     
     
         21 . The method of  claim 18 , further comprising, after pulling the insertion structure, withdrawing the stiff member from the anatomical tract.  
     
     
         22 . The method of  claim 21 , further comprising, after removing the stiff member, withdrawing the insertion structure from the anatomical tract.  
     
     
         23 . The method of  claim 18 , wherein withdrawing at least a portion of the insertion assembly further comprises withdrawing one of the at least one segment release structure that connects the insertion structure to the first segment before pulling the insertion structure.  
     
     
         24 . The method of  claim 22 , wherein: 
 when the first and second segments and the connection structure are mounted on the insertion structure, the at least one segment release structure releasably connects the insertion structure to the first and second segments such that the connection structure is in a collapsed state; and    pulling the insertion structure after withdrawing the segment release structure that connects the insertion structure to the first segment causes the connection structure to expand from the collapsed state and extend through the anatomical constricting structure.    
     
     
         25 . The method of  claim 23 , wherein the at least one segment release structure further releasably connects the insertion structure to the first and second segments such that the first and second segments approximately abut each other.  
     
     
         26 . The method of  claim 18 , wherein the stiff member contacts the first segment at a closed end of the first segment opposite an end of the first segment connected to the connection structure.  
     
     
         27 . The method of  claim 13 , wherein: 
 the insertion assembly comprises: 
 a stiff member that extends through the first and second segments and the connection structure and that contacts the first segment,  
 an insertion structure that extends through the second segment and the connection structure and into the first segment,  
 a first segment release structure that releasably holds the first segment relative to the insertion structure, and  
 a second segment release structure that releasably holds the second segment relative to the insertion structure;  
   at least partially withdrawing at least a portion of the insertion assembly from the anatomical tract relative to the prosthesis comprises removing the first segment release structure from the insertion assembly to release the first segment from the insertion structure; and    pulling at least one of the second portion of the insertion assembly and the portion of the prosthesis comprises partially withdrawing the insertion structure from the anatomical tract.    
     
     
         28 . The method of  claim 26 , wherein at least partially withdrawing at least a portion of the insertion assembly from the anatomical tract relative to the prosthesis further comprises at least partially withdrawing the stiff member from the prosthesis before partially withdrawing the insertion structure from the anatomical tract.  
     
     
         29 . The method of  claim 26 , further comprising, after partially withdrawing the insertion structure from the anatomical tract: 
 removing the second segment release structure from the insertion assembly to release the second segment from the insertion structure; and    withdrawing the insertion structure from the anatomical tract.    
     
     
         30 . The method of  claim 28 , further comprising withdrawing the stiff member from the anatomical tract.  
     
     
         31 . The method of  claim 29 , wherein: 
 when the first and second segments and the connection structure are mounted on the insertion structure, the at least one segment release structure releasably connects the insertion structure to the first and second segments such that the connection structure is in a collapsed state; and    pulling the insertion structure after withdrawing the segment release structure that connects the insertion structure to the first segment causes the connection structure to expand from the collapsed state and extend through the anatomical constricting structure.    
     
     
         32 . The method of  claim 30 , wherein the at least one segment release structure releasably further connects the insertion structure to the first and second segments such that the first and second segments approximately abut each other.  
     
     
         33 . The method of  claim 2 , wherein: 
 locating at least one of the first and second segments relative to at least one of the organ and the cavity comprises advancing the first segment at most partially through the anatomical constricting structure; and    manipulating one of the second portion of the insertion assembly and a portion of the prosthesis comprises advancing the second portion of the insertion assembly further into the anatomical tract to advance the first segment entirely to the far side of the anatomical constricting structure such that the connection structure extends through the anatomical constricting structure.    
     
     
         34 . The method of  claim 33 , wherein: 
 the insertion assembly comprises: 
 a stiff member that extends through the first and second segments and the connection structure and that contacts the first segment,  
 a first portion of the insertion assembly that extends through the second segment and the connection structure and into the first segment,  
 a first segment release structure that releasably holds the first segment relative to the insertion assembly, and  
 a second segment release structure that releasably holds the second segment relative to the insertion assembly; and  
   at least partially withdrawing at least a first portion of the insertion assembly from the anatomical tract relative to the prosthesis comprises removing the first segment release structure from the insertion assembly to release the first segment from the insertion structure; and    advancing the second portion of the insertion assembly comprises advancing the stiff member to advance the first segment entirely to the far side of the anatomical constricting structure.    
     
     
         35 . The method of  claim 34 , wherein: 
 when the first and second segments and the connection structure are mounted on the insertion structure, the at least one segment release structure releasably connects the insertion structure to the first and second segments such that the connection structure is in a collapsed state; and    advancing the insertion structure after withdrawing the segment release structure that connects the insertion structure to the first segment causes the connection structure to expand from the collapsed state and extend through the anatomical constricting structure.    
     
     
         36 . The method of  claim 34 , wherein the at least one segment release structure further releasably connects the insertion assembly to the first and second segments such that the first and second segments approximately abut each other.  
     
     
         37 . The method of  claim 33 , wherein advancing the second portion of the insertion assembly comprises advancing the second portion to place the first segment in a location on the far side of the anatomical constricting structure that is relative to at least one of an organ and a cavity associated with the anatomical tract.  
     
     
         38 . The method of  claim 37 , wherein placing the first segment in a location relative to at least one of an organ and a cavity comprises placing the first segment relative to an opening in a bladder.  
     
     
         39 . The method of  claim 38 , wherein: 
 the first segment comprises a first end connected to the connection structure and a second end opposite the first end, the second end having an opening; and    placing the first segment relative to the opening in the bladder comprises advancing the second end of the first segment through the opening and into the bladder such that fluid held in the bladder can flow into the first segment.    
     
     
         40 . The method of  claim 33 , wherein: 
 the insertion assembly comprises: 
 a stiff member that extends through the first and second segments and the connection structure and that contacts the first segment,  
 an insertion structure that extends through the second segment and the connection structure and into the first segment,  
 a first segment release structure that releasably holds the first segment relative to the insertion structure, and  
 a second segment release structure that releasably holds the second segment relative to the insertion structure;  
   at least partially withdrawing at least a first portion of the insertion assembly from the anatomical tract relative to the prosthesis comprises removing the second segment release structure from the insertion assembly to release the second segment from the insertion structure;    advancing the second portion of the insertion assembly comprises advancing the insertion structure to advance the first segment entirely to the far side of the anatomical constricting structure.    
     
     
         41 . The method of  claim 40 , wherein: 
 when the first and second segments and the connection structure are mounted on the insertion structure, the at least one segment release structure releasably connects the insertion structure to the first and second segments such that the connection structure is in a collapsed state; and    advancing the insertion structure after withdrawing the segment release structure that connects the insertion structure to the second segment causes the connection structure to expand from the collapsed state and extend through the anatomical constricting structure.    
     
     
         42 . The method of  claim 41 , wherein the at least one segment release structure further releasably connects the insertion structure to the first and second segments such that the first and second segments approximately abut each other.  
     
     
         43 . The method of  claim 40 , further comprising: 
 removing the first segment release structure from the insertion structure; and    removing the insertion structure from the anatomical tract.    
     
     
         44 . The method of  claim 40 , wherein advancing the second portion of the insertion assembly comprises advancing the second portion to place the first segment in a location on the far side of the anatomical constricting structure that is relative to at least one of an organ and a cavity associated with the anatomical tract.  
     
     
         45 . The method of  claim 44 , wherein placing the first segment in a location relative to at least one of an organ and a cavity comprises placing the first segment relative to an opening in a bladder.  
     
     
         46 . The method of  claim 45 , wherein: 
 the first segment comprises a first end connected to the connection structure and a second end opposite the first end, the second end having an opening; and    placing the first segment relative to the opening in the bladder comprises advancing the second end of the first segment through the opening and into the bladder such that fluid held in the bladder can flow into the first segment.