Softening expanding ureteral stent
First Claim
1. A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion, the elongated member having an initial member outer diameter and including retention means for retaining the stent within a ureter, the member being formulated of a physiologically acceptable polymer capable of hydrating with concurrent softening and with concurrent expanding from the initial member outer diameter to form a final member outer diameter, the polymer being formulated such that upon hydration the member softens and expands to different degrees at different locations therealong, wherein the elongated member has an initial stiffness above about 100 Shore A and wherein upon hydration the initial stiffness of the distal end portion softens to a final softness which falls below 100 Shore A.
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Accused Products
Abstract
A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion. The elongated member has an initial outer diameter. A retention construction serves for retaining the member within the ureter. The member is formulated of a physiologically acceptable polymer capable of hydrating and expanding from the initial member outer diameter to form a final member outer diameter. The stent can assume differing shapes and can exhibit different degrees of softening at different places along its length.
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Citations
40 Claims
- 1. A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion, the elongated member having an initial member outer diameter and including retention means for retaining the stent within a ureter, the member being formulated of a physiologically acceptable polymer capable of hydrating with concurrent softening and with concurrent expanding from the initial member outer diameter to form a final member outer diameter, the polymer being formulated such that upon hydration the member softens and expands to different degrees at different locations therealong, wherein the elongated member has an initial stiffness above about 100 Shore A and wherein upon hydration the initial stiffness of the distal end portion softens to a final softness which falls below 100 Shore A.
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2. A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion, the elongated member having an initial member outer diameter and including retention means for retaining the stent within a ureter, the member being formulated of a physiologically acceptable polymer capable of hydrating with concurrent softening and with concurrent expanding from the initial member outer diameter to form a final member outer diameter, the polymer being formulated such that upon hydration the member softens and expands to different degrees at different locations therealong, wherein upon hydration the proximal end portion softens to about 70 Shore A to about 70 Shore D, and wherein upon hydration the distal end portion softens to about 30 to about 100 Shore A.
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3. A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion, the elongated member having an initial member outer diameter and including retention means for retaining the stent within a ureter, the member being formulated of a physiologically acceptable polymer capable of hydrating with concurrent softening and with concurrent expanding from the initial member outer diameter to form a final member outer diameter, the polymer being formulated such that upon hydration the member softens and expands to different degrees at different locations therealong wherein the polymer comprises a hydrophilic component and a non-hydrophilic component in a selected ratio, the ratio of hydrophilic to non-hydrophilic component being selected such that upon hydration the polymer softens and expands the initial member outer diameter by from about 5% up to about 300%, and wherein the hydrophilic component is selected from the group consisting of poly(ethylene oxide), polyvinyl pyrrolidone, polyvinyl alcohol, poly(ethylene glycol), polyacrylamide, poly(hydroxy ethyl acrylate), poly(hydroxy ethyl methacrylate), hydroxy ethyl cellulose, hydroxy propyl cellulose, methoxylated pectin gels, agar, starches, modified starches, alginates, hydroxy ethyl carbohydrates and mixtures and copolymers thereof and the non-hydrophilic component is selected from the group consisting of silicone, an aliphatic polyurethane, an aromatic polyurethane, a polyether polyurethane, a polyester polyurethane, an ethylene copolymer, a polyamide, an aliphatic polyester or mixtures or copolymers thereof.
- 24. A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion, the elongated member having an initial member outer diameter and including retention means for retaining the stent within a ureter, the member being formulated of a physiologically acceptable polymer capable of hydrating with concurrent softening and with concurrent expanding from the initial member outer diameter to form an enlarged final member outer diameter, the polymer being formulated such that a selectable time following hydration the final member outer diameter reduces in situ to a smaller diameter.
- 32. A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion, the elongated member having an initial member outer diameter, the member being formulated of a physiologically acceptable polymer capable of hydrating with concurrent softening and with concurrent expanding from the initial member outer diameter to form a final member outer diameter, the polymer being formulated such that retention means for retaining the stent within a ureter forms upon hydration of the stent within the ureter.
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40. A ureteral stent comprising an elongated member having a proximal end portion and a distal end portion joined by a body portion, the elongated member having an initial member outer diameter and including retention means for retaining the stent within a ureter, the member being formulated of an inner section surrounded by an outer layer, the inner section being formulated of a physiologically acceptable polymer capable of hydrating with concurrent softening and with concurrent expanding such that the initial member outer diameter expands to form an enlarged final member outer diameter, the outer layer being formulated such that a selectable time following hydration the outer layer degrades or dissolves such that the final member outer diameter reduces in situ to a smaller diameter.
Specification