Stent pusher assembly

Abstract

Provided is a stent pusher assembly ( 100 ) for positioning a ureteral stent ( 50 ), the stent pusher assembly having an inner ( 102 ) and outer stent pusher ( 104 ). The stent pusher assembly positions the ureteral stent in a patient's kidney and bladder without a bladder fixing portion ( 52 ) of the stent entering a ureteral passage-way, thereby minimizing irritation to the patient.

1 . A method for positioning a ureteral stent in a kidney, ureteral passageway and bladder of a patient using a stent pusher assembly having an inner and outer pusher, the ureteral stent including a bladder portion configured to be positioned in the bladder, a kidney portion configured to be positioned in the kidney and the ureteral passageway, and at least one tether coupled to the bladder portion and the kidney portion, the method including:
 advancing a guidewire into the bladder, the ureteral passageway and the kidney;   advancing the kidney portion and bladder portion over the guidewire;   advancing the outer pusher over the guidewire;   advancing the outer pusher along the guidewire until a second end of the outer pusher abuts a first end of the bladder portion;   advancing the outer pusher towards the kidney to advance the bladder portion and kidney portion until the kidney portion is substantially positioned in the ureteral passageway;   advancing the inner pusher over the guidewire, through a lumen of the outer pusher and through a lumen of the bladder portion until a second end of the inner pusher abuts a second end of the kidney portion; and   advancing the inner pusher towards the kidney to advance the kidney portion such that the second end of the kidney portion is disposed in the ureteral passageway and a first end of the kidney portion is disposed in the kidney.   
     
     
         2 . The method according to  claim 1 , wherein the kidney portion and bladder portion are in respective restrained shapes when the guidewire extends through the kidney portion and bladder portion. 
     
     
         3 . The method according to  claim 1 , further including:
 withdrawing the guidewire from the first end of the kidney portion to allow the first end to move to its unrestrained shape to secure the kidney portion in the kidney; and   withdrawing the guidewire, inner pusher and outer pusher from the bladder portion to allow the bladder portion to move to its unrestrained shape to prevent the bladder portion from migrating into the ureteral passageway.   
     
     
         4 . The method according to  claim 1 , wherein advancing the outer pusher towards the kidney until the kidney portion is substantially positioned in the ureteral passageway includes advancing the outer pusher until a portion of the kidney portion is positioned in the bladder and a majority of the kidney portion is positioned in the ureteral passageway. 
     
     
         5 . The method according to  claim 1 , wherein the outer pusher has an axial length less than an axial length of the inner pusher. 
     
     
         6 . The method according to  claim 1 , wherein an outer diameter of the inner pusher is equal to or greater than an outer diameter of the kidney portion to allow the inner pusher to advance the kidney portion without entering a lumen of the kidney portion. 
     
     
         7 . The method according to  claim 1 , wherein an inner diameter of the bladder portion is greater than an outer diameter of the kidney portion to allow the inner pusher having an outer diameter equal to or greater than the outer diameter of the kidney portion to be advanced through the bladder portion. 
     
     
         8 . A pusher assembly for positioning a ureteral stent in a kidney, ureteral passageway and bladder of a patient, the pusher assembly including:
 an inner stent pusher including a body having a lumen and a handle member coupled to a first end of the body; and   an outer stent pusher including a body having a lumen and a handle member coupler to a first end of the body,   wherein the body of the inner stent pusher has an axial length greater than an axial length of the body of the outer stent pusher, and   wherein the body of the inner stent pusher has an outer diameter that is less than an inner diameter of the body of the outer stent pusher to allow the inner stent pusher to move through the lumen of the outer stent pusher during placement of the ureteral stent.   
     
     
         9 . The pusher assembly according to  claim 8 , wherein the handle member of the inner stent pusher acts as a stop to prevent the first end of the body of the inner stent pusher from entering the lumen of the outer stent pusher during placement of the ureteral stent. 
     
     
         10 . The pusher assembly according to  claim 8 , further including a guidewire configured to extend through the lumen in the inner stent pusher. 
     
     
         11 . The pusher assembly according to  claim 8  in combination with the ureteral stent, wherein the ureteral stent includes:
 a bladder portion configured to be positioned in the bladder; 
 a kidney portion configured to be positioned in the kidney and the ureteral passageway; and 
 at least one tether coupled to the bladder portion and the kidney portion. 
 
     
     
         12 . (canceled) 
     
     
         13 . The combination according to  claim 11 , wherein the bladder portion is biased in an unrestrained position. 
     
     
         14 . The combination according to  claim 11 , wherein the guidewire is configured to extend through the bladder portion during placement of the stent to place the bladder portion in a restrained position. 
     
     
         15 . The combination according to  claim 14 , wherein the bladder portion is substantially straight when in the restrained position and curved when in the unrestrained position. 
     
     
         16 . The combination according to  claim 11 , wherein the kidney portion has a resilient fixing portion configured to be positioned in the kidney and a ureter portion configured to be positioned in the kidney and the ureteral passageway to place the ureteral passageway in an open state, the resilient fixing portion being biased in an unrestrained position. 
     
     
         17 . The combination according to  claim 16 , wherein the guidewire is configured to extend through the kidney portion during placement of the stent to place the resilient fixing portion in a restrained position. 
     
     
         18 . The combination according to  claim 16 , wherein the resilient fixing portion is substantially straight when in the restrained position and curved when in the unrestrained position, 
     
     
         19 . The combination according to  claim 11 , wherein the bladder portion and the fixing portion are movable between a restrained position when being positioned in the bladder and kidney by the pusher assembly and the unrestrained position when positioned in the bladder and kidney. 
     
     
         20 . The combination according to  claim 11 , wherein an outer diameter of the inner stent pusher is equal to or greater than an outer diameter of the kidney portion to allow the inner pusher to advance the kidney portion without entering a lumen of the kidney portion. 
     
     
         21 . The combination according to  claim 11 , wherein an inner diameter of the bladder portion is greater than an outer diameter of the kidney portion to allow the inner pusher having an outer diameter equal to or greater than the outer diameter of the kidney portion to be advanced through the bladder portion.