# US 6,719,804 B2 · Medical stent and related methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,719,804 B2 - Document ID: US6719804B2 - Status: Granted - Kind: B2 - Application number: 10/032,712 - Filed: 2001-10-24 - Published: 2002-10-03 - Granted: 2004-04-13 - Earliest claimed: 2001-04-02 - Assignees: SciMed Life Systems, Inc. - Inventors: Ernest J. St. Pierre - Web page: https://patentgrep.com/patent/US6719804B2 ## CPC - A61M 27/008: {pre-shaped, for use in the urethral or ureteral tract} - A61M 25/0009: {Making of catheters or other medical or surgical tubes} - A61F 2250/0019: differing in hardness, e.g. Vickers, Shore, Brinell - A61M 25/0041: {pre-formed, e.g. specially adapted to fit with the anatomy of body channels (urethral catheters A61F2/04)} - A61M 25/0054: {with regions for increasing flexibility} - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract A medical stent is sized for placement in a ureter. The stent includes a first section which includes a first material, defines a lumen, and includes a first coil completing at least one revolution. A second section of the stent includes a second material, defines a lumen, and includes a second coil completing at least one revolution. A third section defines a lumen and is located between the first and second sections. The third section includes a co-extrusion of the first and second materials. One of the first or second sections is harder than the other section. ## Claims ### Claim 1 A medical stent comprising: a single-piece, extruded stent body which does not substantially soften when exposed to a temperature of a human body, at least a portion of the stent body sized for placement in a ureter and at least a section of the stent body defining holes therethrough, the stent body comprising: a first section defining a lumen and comprising a first coil completing at least one revolution, the first section comprising a first material having a first durometer value; a second section defining a lumen and comprising a second coil completing at least one revolution, the second section comprising a second material having a second durometer value, wherein the second durometer value is greater than the first durometer value; and a third section defining a lumen and located between the first and second sections, wherein the third section comprises a co-extrusion of the first and second materials that is disposed between the first coil and the second coil and wherein an outer surface of the third section smoothly transitions to outer surfaces of the first and second sections immediately proximate the third section and an inner diameter of the third section is substantially constant through the third section and on either side of the third section immediately proximate to the third section in the first and second sections. ### Claim 2 (depends on 1) The stent of claim 1 wherein the first material comprises ethylene vinyl acetate. ### Claim 3 (depends on 1) The stent of claim 1 wherein the first material has a durometer value of about 70 to about 90 on a Shore A scale. ### Claim 4 (depends on 1) The stent of claim 1 wherein the second material has a durometer value of about 80 to about 95 on a Shore A scale. ### Claim 5 (depends on 1) The stent of claim 1 wherein a cross-section of the lumen in at least one of the first, second, and third sections is circular. ### Claim 6 (depends on 1) The stent of claim 1 wherein a cross-section of at least one of the first, second, and third sections is circular. ### Claim 7 (depends on 1) The stent of claim 1 wherein at least one of the first, second, and third section comprises a radiopaque material. ### Claim 8 A medical stent comprising: a single-piece, extruded stent body which does not substantially soften when exposed to a temperature of a human body, at least a portion of the stent body sized for placement in a ureter and at least a section of the stent body defining holes therethrough, the stent body comprising: a first section defining a lumen and comprising a first coil completing at least one revolution, the first section comprising a first material and the first coil having a first retention strength; a second section defining a lumen and comprising a second coil completing at least one revolution, the second section comprising a second material and the second coil having a second retention strength, wherein the second retention strength is greater than the first retention strength; and a third section defining a lumen and located between the first and second sections, wherein the third section comprises a co-extrusion of the first and second materials that is disposed between the first coil and the second coil and wherein an outer surface of the third section smoothly transitions to outer surfaces of the first and second sections immediately proximate the third section and an inner diameter of the third section is substantially constant through the third section and on either side of the third section immediately proximate to the third section in the first and second sections. ### Claim 9 A method for placing a medical stent comprising: inserting a medical stent into a ureter, the medical stent comprising: a single-piece, extruded stent body which does not substantially soften when exposed to a temperature of a human body, at least a portion of the stent body sized for placement in a ureter and at least a section of the stent body defining holes therethrough, the stent body comprising: a first section defining a lumen and comprising a first coil completing at least one revolution, the first section comprising a first material having a first durometer value; a second section defining a lumen and comprising a second coil completing at least one revolution, the second section comprising a second material having a second durometer value, wherein the second durometer value is greater than the first durometer value; and a third section defining a lumen and located between the first and second sections, wherein the third section comprises a co-extrusion of the first and second materials that is disposed between the first coil and the second coil and wherein an outer surface of the third section smoothly transitions to outer surfaces of the first and second sections immediately proximate the third section and an inner diameter of the third section is substantially constant through the third section and on either side of the third section immediately proximate to the third section in the first and second sections.