Stent having timed-release indicator

Abstract

A medical device includes an elongate body configured to be disposed within a urinary tract of a patient such that a first end portion of the elongate body is disposed at a first location of the urinary tract and a second end portion of the elongate body is disposed at a second, different location of the urinary tract. The elongate body defines a lumen that is configured to convey urine from the first location of the urinary tract to the second location of the urinary tract. An agent is formulated to visually alter urine of the patient, the agent is coupled to the elongate body and releasable into the patient's urine.

What is claimed is: 
     
         1 . A medical device, comprising:
 an elongate body configured to be disposed within a urinary tract of a patient such that a first end portion of the elongate body is disposed at a first location of the urinary tract and a second end portion of the elongate body is disposed at a second, different location of the urinary tract, the elongate body defining a lumen, the lumen being configured to convey urine from the first location of the urinary tract to the second location of the urinary tract; and   an agent formulated to visually alter urine of the patient, the agent being coupled to the elongate body and releasable into the patient's urine.   
     
     
         2 . The medical device of  claim 1 , wherein the agent is formulated to change the color of the urine. 
     
     
         3 . The ureteral stent of  claim 1 , further comprising:
 a barrier disposed to inhibit release of the agent from the elongate body and formulated to be degraded by contact with the patient's urinary tract or urine therein sufficient to allow release of the agent.   
     
     
         4 . The medical device of  claim 1 , wherein the agent is disposed on a release element coupled to the elongate body. 
     
     
         5 . The medical device of  claim 1 , wherein the lumen defined by the elongate body is a first lumen, the elongate body further defining a second lumen, the agent being disposed within at least a portion of one of the first lumen or the second lumen, and further including a barrier coupled to the elongate body to fluidically isolate the agent from the ureter, the barrier being formulated to be degraded by contact with the patient's urinary tract or urine therein sufficiently to allow release of the agent. 
     
     
         6 . The medical device of  claim 1 , further comprising:
 a barrier disposed between the agent and the lumen to inhibit release of the agent into the lumen.   
     
     
         7 . The medical device of  claim 1 , further comprising:
 a barrier coupled to an outer surface of the elongate body, the agent disposed between the elongate body and the barrier.   
     
     
         8 . The medical device of  claim 1 , wherein the first location is a kidney and the second location is a bladder. 
     
     
         9 . The medical device of  claim 1 , wherein the elongate body is configured to be completely degraded by a mammalian body. 
     
     
         10 . A medical device, comprising:
 an elongate body configured to be disposed at least partially into a ureter of a patient;   a barrier, disposed on at least a portion of the elongate body, being biodegradable by contact with a mammalian body and/or bodily fluids; and   an agent coupled to the elongate body and fluidically blocked from the mammalian body by the barrier, the agent configured to be released into at least one of the ureter, a bladder or a kidney of the patient when at least a portion of the barrier is sufficiently degraded by the mammalian body.   
     
     
         11 . The medical device of  claim 10 , wherein the elongate body has a proximal end and a distal end, and defines a lumen between the proximal end and the distal end. 
     
     
         12 . The medical device of  claim 10 , wherein the agent is configured to visually alter urine of the patient. 
     
     
         13 . The medical device of  claim 10 , wherein the elongate body defines a lumen, the agent being disposed within the lumen between the barrier and the elongate body. 
     
     
         14 . The medical device of  claim 10 , wherein the elongate body and the barrier define a reservoir, the agent disposed within the reservoir. 
     
     
         15 . The medical device of  claim 10 , wherein the agent is incorporated within the barrier. 
     
     
         16 . The medical device of  claim 10 , wherein the agent is disposed on a release element, the release element is coupled to the elongate body. 
     
     
         17 . The medical device of  claim 10 , wherein the elongate body defines a first lumen and a second lumen, the agent being disposed in at least one of the first lumen or the second lumen. 
     
     
         18 . The medical device of  claim 10 , wherein the agent is formulated to alter a color of urine of the patient. 
     
     
         19 . The medical device of  claim 10 , wherein the elongate body and the barrier are each formulated to be completely degradable by the mammalian body. 
     
     
         20 . A method, comprising:
 determining the pH of the urine of a patient;   based on the pH, selecting one of a plurality of release elements to be placed in a urinary tract of the patient, each release element from the plurality of release elements configured to be coupled to a ureteral stent, the stent configured to be disposed at least partially within a ureter of a patient, the release element including an agent and a barrier, the agent configured to alter a color of urine of the patient, the barrier being configured and formulated to inhibit release of the agent into the ureter and to be degraded by the ureter and/or urine therein sufficient to release the agent within a predetermined period of disposal of the stent in the ureter at a given pH.   
     
     
         21 . The method of  claim 20 , further comprising:
 coupling the selected release element to a stent.   
     
     
         22 . The method of  claim 21 , further comprising:
 disposing the stent at least partially within the ureter of a patient.