Ureteral stent for placement in a kidney and bladder

1. A ureteral stent for placement in a bladder, a kidney and a ureteral passageway connecting the bladder and the kidney, the ureteral stent including:

a bladder portion configured to be positioned in the bladder, the bladder portion being resilient and biased in an unrestrained position to prevent the bladder portion from migrating into the ureteral passageway when positioned in the bladder;

a kidney portion configured to be positioned in the kidney and the ureteral passageway, the kidney portion being tubular and defining a tubular ureter portion configured to be positioned in the kidney and the ureteral passageway to place the ureteral passageway in an open state and a tubular resilient fixing portion biased in an unrestrained position to secure the resilient fixing portion in the kidney when positioned in the kidney;

a tether connecting the bladder portion and the ureter portion to allow the bladder portion to float in the bladder and to allow a ureter orifice connecting the ureteral passageway to the bladder to move between a compressed state and an uncompressed state, wherein the tether has first and second ends knotted together outside the bladder and kidney portions forming a knotted portion; and

a sleeve coupled to a wall of the ureter portion that covers the knotted portion to prevent the knotted portion from irritating the ureter, the sleeve having a length less than a length of the ureter portion.

2. The ureteral stent according to claim 1 , wherein the bladder portion and the fixing portion are movable between respective restrained positions when being positioned in the bladder and kidney, respectively, and the respective unrestrained positions when positioned in the bladder and kidney, respectively.

3. The ureteral stent according to claim 2 , wherein the bladder portion and kidney portion are substantially straight when in the respective restrained positions and curved when in the respective unrestrained positions.

4. The ureteral stent according to claim 1 , wherein the bladder portion and kidney portion each include at least one radiopaque element on outer surfaces thereof to assist an operator in positioning the stent.

5. The ureteral stent according to claim 4 , wherein the bladder portion and kidney portion have first and second ends, respectively, each end having at least one radiopaque element.

6. The ureteral stent according to claim 1 , wherein the bladder portion includes a tip at a first end opposite a second end coupled to the tether, the tip having a stiffness greater than a stiffness of a remaining portion of the bladder portion.

7. The ureteral stent according to claim 1 , wherein the bladder portion and ureter portion of the kidney portion each include a least one opening in a wall thereof providing a passage between an outside of the bladder and kidney portions and an inside of the bladder and kidney portions for receiving the tether, wherein the tether extends from the inside of the bladder and kidney portions to the outside of the bladder and kidney portions, and wherein the tether has a first end and a second end coupled together outside the bladder and kidney portions forming a coupled tether portion.

8. The ureteral stent according to claim 1 , wherein the tether is a suture.

9. The ureteral stent according to claim 1 , wherein the bladder portion and the fixing portion are a flexible loop when in their unrestrained positions.

10. The ureteral stent according to claim 1 , wherein the bladder portion and the fixing portion are J-shaped when in their unrestrained positions.

11. The ureteral stent according to claim 1 , wherein the bladder portion and the fixing portion are helical when in their unrestrained positions.

12. The ureteral stent according to claim 1 , wherein the kidney portion has a durometer between 50 shore A and 80 shore A.

13. The ureteral stent according to claim 1 , wherein the resilient fixing portion has a durometer greater than a durometer of the ureter portion.

14. The ureteral stent according to claim 1 , wherein the bladder portion has a durometer between 25 shore A and 50 shore A.

15. The ureteral stent according to claim 1 , wherein the kidney portion has transition zones along its length going from a harder durometer at the resilient fixing portion to a softer durometer at an end of the ureter portion connected to the tether.

16. A ureteral stent for placement in a bladder, a kidney and a ureteral passageway connecting the bladder and kidney, the ureteral stent including:

a bladder portion configured to be positioned in the bladder, the bladder portion being resilient and biased in an unrestrained position to prevent the bladder portion from migrating into the ureteral passageway when positioned in the bladder;

a kidney portion configured to be positioned in the kidney and the ureteral passageway, the kidney portion having a ureter portion configured to be positioned in the kidney and the ureteral passageway to place the ureteral passageway in an open state and a resilient fixing portion biased in an unrestrained position to secure the resilient fixing portion in the kidney when positioned in the kidney;

at least one tether connected to the bladder portion and the ureter portion to allow the bladder portion to float in the bladder and to allow a ureter orifice connecting the ureteral passageway to the bladder to move between a compressed state and an uncompressed state, wherein the tether has a length and first and second ends at opposite ends of the length from one another, and wherein the first and second ends are knotted together outside the bladder and kidney portions forming a knotted portion; and

a sleeve coupled to the wall of the ureter portion that covers the knotted portion to hold down the knotted portion and part of the tether to prevent the knotted portion from irritating a patient and to allow the tether to lie down to reduce a thickness of the ureter portion, the sleeve having a length less than a length of the ureter portion.