US20070049804A1 - One-piece retractable stent - Google Patents

One-piece retractable stent Download PDF

Info

Publication number
US20070049804A1
US20070049804A1 US11/439,052 US43905206A US2007049804A1 US 20070049804 A1 US20070049804 A1 US 20070049804A1 US 43905206 A US43905206 A US 43905206A US 2007049804 A1 US2007049804 A1 US 2007049804A1
Authority
US
United States
Prior art keywords
medical device
intraluminal medical
stent
retractor
intraluminal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/439,052
Other languages
English (en)
Inventor
Albert Wong
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US11/439,052 priority Critical patent/US20070049804A1/en
Priority to PCT/US2006/020089 priority patent/WO2007024310A2/fr
Publication of US20070049804A1 publication Critical patent/US20070049804A1/en
Priority to US12/393,039 priority patent/US9144507B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/94—Stents retaining their form, i.e. not being deformable, after placement in the predetermined place

Definitions

  • This invention relates to endoprosthesis devices adapted for implantation into a body lumen such as, but not limited to, a blood vessel or a bile duct to maintain the patency thereof. More particularly, the present invention relates to a retractable stent.
  • Coronary angioplasty is a medical procedure used to prop open clogged arteries. This is often accompanied by insertion of an intraluminal medical device, for example, a stent, to help keep the artery open.
  • an intraluminal medical device for example, a stent
  • current stents while sufficient in strength to keep clogged arteries open, fail in that they cause inflammation and immune responses that encourage re-blocking of the artery in a condition known as restenosis.
  • re-clogging restenosis
  • retrieving the implanted stent is a problem.
  • Biliary stent implantation is a medical procedure used to treat problems associated with blockages in the bile ducts. The procedure involves the implantation of a stent to help keep the passageway open. Current stents used in the bile ducts can cause inflammation and immune responses and also are not easily retrievable, sometimes requiring surgery. Biliary stents often need to be replaced every few months (because they get clogged up); thus, the fact that current stents are not easily retrievable is a major problem as they need to be replaced frequently.
  • Stents are also implanted in other structures, such as, but not limited to, peripheral arteries and veins, esophagus, trachea or large bronchi, ureters, and urethra. Any of these medical procedures involves the implantation of a stent to assist in maintaining the patency of the passageway the stent is implanted in.
  • Current stents used in these structures can cause inflammation and immune responses and often are not easily retrievable, sometimes requiring surgery.
  • Stents in some of these structures also need to be replaced relatively frequently, something that presents a major problem associated with current stents since current stents are not easily retrievable once placed.
  • Prior art i.e., current stents
  • metallic wire mesh and bioresorbable. Both such categories have flaws.
  • the metallic wire mesh stents cause inflammatory and immune responses that may lead to restenosis, besides causing other localized tissue damage and trauma.
  • the bioresorbable stents' only advantage over metallic wire mesh stents is that they degrade and go away after 5-10 years.
  • wire mesh stents behave exactly the same as wire mesh stents: a similar, if not increased, rate of immune responses (especially due to breakdown/degradation products generated during stent degradation), a requirement for surgical intervention if removal becomes necessary, and a similar, if not increased, rate of inflammatory responses (especially due to breakdown/degradation products generated during stent degradation).
  • Bioresorbable stents were invented to deal with the core problem of metal stents: inflammatory and immune responses eventually lead to restenosis, blocking the duct or vessel the stent originally opened, and requiring retrieval of the stent, which often involves surgery (although other stents can occasionally be retrieved without surgery, retrieving coronary stents in particular always requires open heart surgery).
  • Bioresorbable stents attempted to solve this problem by degrading automatically within five to ten years; however, serious immune and inflammatory responses caused by this degradation often occur before the stent is completely degraded, in which case it must be surgically removed; also, the associated memory immune responses associated with the immune responses and inflammation often preclude bioresorbable stents from being used more than once in a person (that is, it is often impossible to implant a second bioresorbable stent in a person after the first bioresorbable stent has degraded or been retrieved).
  • the one-piece retractable stent of the present invention belongs to a completely different stent category and is the first and only member of this new category. It is made of a one-piece sheet material (an elastic metallic polymer, for example, is a good candidate). Also, it is not bioresorbable. Because it is one-piece (which minimizes damage to the luminal membranes of ducts or vessels the stent is deployed in), and because it is not bioresorbable, it prevents, or at least minimizes, inflammation, immune responses, and restenosis.
  • the structure of the invention allows it to be collapsed when desired at any time and retrieved easily, without need for surgical intervention (e.g., if deployed in a coronary artery, open heart surgery would not be necessary to retrieve my stent).
  • Existing stents cannot be collapsed due to their design; once expanded/deployed, their many pieces lock into place permanently, making it impossible to collapse the stent, and thus making it impossible to retrieve the stent without open heart surgery in the case of coronary stents, or at least making it quite difficult to retrieve the stent, in the case of other stents.
  • the present invention further relates to the one-piece retractable stent in combination with a retractor device.
  • One method involves the stent being attached to a retractor device, which may be attached to a delivery device, for example, a catheter delivery device, if necessary. Variations of this method may be used without departing from the spirit of the method. Other methods may be used to deliver the stent depending on where the stent needs to be delivered to.
  • One method involves a retractor device, attached to a delivery device, for example, a catheter delivery device, being delivered to the location of the stent.
  • the retractor then attaches to or exerts force on one or more portions of the stent, and pulls it into the collapsed state.
  • the delivery device is then employed to extract the retractor device and the attached stent. Variations of this method may be used without departing from the spirit of the method.
  • This invention provides much needed improvements over both metallic and bioresorbable stents. It provides retractability, thus never requiring open heart surgery for removal, over both metallic and bioresorbable stents. Also, it provides reduced inflammation and immune responses over both metallic and bioresorbable stents.
  • the invention functions similarly to a regular metal stent, but, because of its special one-piece sheet design, it can be retracted with a special retractor in a minor surgical procedure similar to the procedure for implanting the stent (without major surgery, such as open heart surgery in the case of coronary stents) and replaced with a new stent if and when it needs to be replaced with a new one;
  • the present invention provides a generally tubular, expandable, retractable intraluminal device having a central longitudinal axis generally referred to as a stent.
  • the stent of the present invention is comprised of a one-piece sheath and, in a collapsed state, has at least some portions which project inward into the central longitudinal axis.
  • FIG. 1 provides a view of the initial sheet of material 14 (e.g., a metallic polymer) and shows how it is curled into a fully expanded stent 10 .
  • the initial sheet of material 14 e.g., a metallic polymer
  • FIG. 2 provides a 3-D view of the fully expanded stent 10 as it is right after the first step of manufacturing (and also later in the stent's life when it is deployed in a patient in vivo).
  • FIG. 3 provides a 2-D cross sectional view of the configuration the stent is in after it is collapsed in the final stage of the manufacturing process 12 .
  • FIG. 4 provides a 3-D sideways view of the collapsed stent after manufacture 12 .
  • FIG. 5 is a detailed view of the retractor 6 illustrating the twin clamps 2 and 4 for delivery and retrieval of the stent.
  • FIG. 6 is a detailed end-on view of the retractor 6 about to collapse the expanded/deployed stent 10 and retrieve it.
  • FIG. 7 shows one possible alternative embodiment of the initial sheet of material 16 from which the stent can be made.
  • FIG. 8 provides a 3-D view of one possible alternative embodiment 18 of the fully expanded stent as it is right after the final step of manufacturing (and also later in the stent's life when it is deployed in a patient in vivo).
  • FIG. 9 provides a 2-D cross-sectional view of the stent in the final collapsed state 8 , after it is retracted.
  • FIG. 10 provides a view of a sample catheter delivery device 20 that could be used in conjunction with the retractor 6 to deliver the stent.
  • FIG. 11 shows another possible alternative embodiment of the initial sheet of material 22 from which the stent can be made.
  • FIG. 1 a view of the initial sheet of material 14 (e.g., a metallic polymer) that shows how it is curled into a stent 10 is provided by FIG. 1 .
  • the dimensions of the initial sheet of material 14 may be altered as necessary to produce stents of different sizes and dimensions.
  • FIG. 2 A 3-D view of the fully expanded stent 10 as it is right after the first step of manufacturing, in this particular embodiment, and also later in the stent's life when it is deployed in a patient in vivo, is provided in FIG. 2 .
  • the manufacturing protocol is only a sample and is not intended to be the sole means by which the stent can be made. Other possible manufacturing protocols may bypass this stage.
  • FIG. 3 provides a 2-D cross sectional view of the configuration the stent 12 is in after it is collapsed in the final stage of the manufacturing process. Note that it may be possible to use a manufacturing protocol not stated here to directly manufacture the stent in this configuration 12 , bypassing the configuration 10 in FIG. 2 and eliminating the need for a step to collapse the stent.
  • FIG. 5 A detailed view of the retractor 6 in this particular embodiment is provided in FIG. 5 , illustrating inner 2 and outer 4 forks/clamps for delivery and retrieval of the stent.
  • Other retractor configurations or geometries may be used without deviating from the intended purpose of the retractor.
  • FIG. 4 A 3-D sideways view of the collapsed stent after manufacture 12 , in the preferred embodiment, is provided by FIG. 4 .
  • sample catheter delivery device 20 shown attached to the retractor 6 in FIG. 10 is intended for illustrative purposes only.
  • Catheter delivery devices useful for delivery of a medical device of the type described herein are well known to those of ordinary skill in the art and as such any suitable delivery catheter may be employed herein. Additionally, in certain applications of the stent, it may not be necessary to use a catheter delivery device.
  • the stent 12 and the retractor 6 are typically attached to the catheter for delivery to the implantation site where the retractor expands the stent.
  • the stent is now in its fully expanded state 10 .
  • the retractor is then disconnected from the stent.
  • the retractor is collapsed and the catheter 20 and retractor 6 are then removed from the body lumen leaving the stent 10 behind.
  • FIG. 6 is a detailed end-on view of the retractor's inner 2 and outer 4 forks about to collapse the expanded/deployed stent 10 and retrieve it.
  • Other retractor configurations or geometries may be used without deviating from the intended purpose of the retractor.
  • FIG. 9 A 2-D cross-sectional view of the state the stent is in 8 after it is collapsed by the retractor's inner 2 and outer 4 forks (this is the final stage of the stent's life and the stent is now in its final collapsed state 8 ) is provided by FIG. 9 .
  • the stent may be formed according to any method known in the art including the following sample manufacturing protocol, which has been designed for an average-sized stent made using an elastic metallic polymer. Please note that this invention can be produced for any size and can also be made with materials other than elastic metallic polymers.
  • FIG. 7 shows one possible alternative embodiment of the sheet of material 16 from which the stent is made.
  • This sheet 16 has regularly shaped rectangular holes cut into it from both ends at regular intervals to allow blood vessel endothelium to grow onto and along the stent's luminal surface easier. Please note that this is only one of very many possible additional embodiments of the sheet geometry.
  • FIG. 8 provides a 3-D view of a stent 18 made from the possible alternative sheet embodiment 16 shown in FIG. 7 .
  • FIG. 11 shows another possible alternative embodiment for the sheet of material 22 from which the stent is made.
  • This sheet 22 has regularly shaped circular holes cut into it at regular spaces to allow blood vessel endothelium to grow onto and along the stent's luminal surface easier. Please note that this is only one of many possible additional embodiments of the sheet geometry.
  • the retractable stent can be easily modified from the preferred embodiment to contain perforations or holes of varying shapes, sizes, and amounts in the stent wall.
  • the presence of such holes can help to further reduce the incidents and severity of inflammation and immune responses.
  • the presence of such holes would allow for easier and faster growth of endothelial tissue onto and then along the luminal surface of the stent; the presence of endothelial tissue coating the luminal surface of the stent would inhibit inflammatory and immune responses, which can be triggered or enhanced by the detection of foreign material.
  • the retractable stent can be made easily at any length desired without altering any aspect of its design. This feature makes it possible, in the case of very short clogs, clots, or blockages, to avoid using a stent that is longer than necessary; the shorter the stent, the lower the chance of inflammation and immune responses. Many current stents, on the other hand, have a minimum length which they can be made at.
  • the retractable stent can be made easily at any diameter desired without altering any aspect of its design. This feature makes it possible to use the stent in any duct or vessel desired even if said duct or vessel has a small or non-standard diameter. Many current stents, on the other hand, have a minimum diameter which they can be made at, meaning that they could not be used in vessels or ducts with a diameter less than said minimum diameter.
  • the retractable stent's smooth one-piece design prevents injury to the wall of a duct or vessel during expansion/deployment of said stent in said duct or vessel.
  • One of the major triggers of inflammation, immune responses, and restenosis associated with current stents is damage to the wall of a duct or vessel caused by the struts on said current stents during expansion/deployment in said duct or vessel.
  • the retractable stent of this invention allows all of the benefits associated with the use of current stents while eliminating most, if not all, of the drawbacks. It can be deployed as a normal stent but can also be retracted easily when necessary or if desired. It reduces inflammation and immune responses and naturally inhibits restenosis, one of the main problems associated with the use of stents. Its simple one-piece design allows it to be manufactured cheaply and easily for a variety of dimensions, and also allows custom dimensions to be made upon order.
  • the retractable stent of this invention has an additional advantage in that it can be made with holes or perforations of varying shapes, sizes, and amounts to improve its function and lengthen its longevity in some applications, such as when using in a coronary artery; the stent can also be made without holes or perforations if desired.
US11/439,052 2005-08-25 2006-05-23 One-piece retractable stent Abandoned US20070049804A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US11/439,052 US20070049804A1 (en) 2005-08-25 2006-05-23 One-piece retractable stent
PCT/US2006/020089 WO2007024310A2 (fr) 2005-08-25 2006-05-24 Stent retractable monolithique
US12/393,039 US9144507B2 (en) 2005-08-25 2009-02-26 Method for surgical treatment of occlusive disease

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US71082505P 2005-08-25 2005-08-25
US11/439,052 US20070049804A1 (en) 2005-08-25 2006-05-23 One-piece retractable stent

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US12/393,039 Continuation US9144507B2 (en) 2005-08-25 2009-02-26 Method for surgical treatment of occlusive disease

Publications (1)

Publication Number Publication Date
US20070049804A1 true US20070049804A1 (en) 2007-03-01

Family

ID=37772067

Family Applications (2)

Application Number Title Priority Date Filing Date
US11/439,052 Abandoned US20070049804A1 (en) 2005-08-25 2006-05-23 One-piece retractable stent
US12/393,039 Expired - Fee Related US9144507B2 (en) 2005-08-25 2009-02-26 Method for surgical treatment of occlusive disease

Family Applications After (1)

Application Number Title Priority Date Filing Date
US12/393,039 Expired - Fee Related US9144507B2 (en) 2005-08-25 2009-02-26 Method for surgical treatment of occlusive disease

Country Status (2)

Country Link
US (2) US20070049804A1 (fr)
WO (1) WO2007024310A2 (fr)

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5718973A (en) * 1993-08-18 1998-02-17 W. L. Gore & Associates, Inc. Tubular intraluminal graft
US6015429A (en) * 1994-09-08 2000-01-18 Gore Enterprise Holdings, Inc. Procedures for introducing stents and stent-grafts
US6017362A (en) * 1994-04-01 2000-01-25 Gore Enterprise Holdings, Inc. Folding self-expandable intravascular stent
US20030055484A1 (en) * 1994-08-31 2003-03-20 Lilip Lau Exterior supported self-expanding stent-graft
US20030055495A1 (en) * 2001-03-23 2003-03-20 Pease Matthew L. Rolled minimally-invasive heart valves and methods of manufacture
US6706064B1 (en) * 1997-06-28 2004-03-16 Anson Medical Limited Expandable device
US6733525B2 (en) * 2001-03-23 2004-05-11 Edwards Lifesciences Corporation Rolled minimally-invasive heart valves and methods of use
US20040111142A1 (en) * 2000-02-01 2004-06-10 Rourke Jonathan M. Micro-porous mesh stent with hybrid structure
US20040210298A1 (en) * 2001-04-27 2004-10-21 Intek Technology, L.L.C. Methods for delivering, repositioning and/or retrieving self-expanding stents
US6843803B2 (en) * 1995-12-01 2005-01-18 Medtronic Vascular, Inc. Bifurcated intraluminal prostheses construction and methods
US20060184231A1 (en) * 2005-02-08 2006-08-17 Rucker Brian K Self contracting stent

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4762128A (en) * 1986-12-09 1988-08-09 Advanced Surgical Intervention, Inc. Method and apparatus for treating hypertrophy of the prostate gland
AU669338B2 (en) * 1991-10-25 1996-06-06 Cook Incorporated Expandable transluminal graft prosthesis for repair of aneurysm and method for implanting
US5474563A (en) * 1993-03-25 1995-12-12 Myler; Richard Cardiovascular stent and retrieval apparatus
US5735892A (en) * 1993-08-18 1998-04-07 W. L. Gore & Associates, Inc. Intraluminal stent graft
US5746745A (en) * 1993-08-23 1998-05-05 Boston Scientific Corporation Balloon catheter
US5868780A (en) * 1996-03-22 1999-02-09 Lashinski; Robert D. Stents for supporting lumens in living tissue
EP1095635A4 (fr) * 1999-05-06 2007-06-20 Kanji Inoue Appareil plieur d'instrument et utilisation de cet appareil
US7181261B2 (en) * 2000-05-15 2007-02-20 Silver James H Implantable, retrievable, thrombus minimizing sensors
US6796960B2 (en) * 2001-05-04 2004-09-28 Wit Ip Corporation Low thermal resistance elastic sleeves for medical device balloons
US20040034405A1 (en) * 2002-07-26 2004-02-19 Dickson Andrew M. Axially expanding polymer stent
US7311727B2 (en) * 2003-02-05 2007-12-25 Board Of Trustees Of The University Of Arkansas Encased stent
ES2346059T3 (es) * 2003-03-26 2010-10-08 Biosensors International Group Ltd. Cateter de suministro de implantes con juntas erosionables electroliticamente.
JP4975609B2 (ja) * 2004-02-27 2012-07-11 エーオーテックス， インコーポレイテッド 補綴心臓弁送達システムおよびその方法
US8038704B2 (en) * 2005-07-27 2011-10-18 Paul S. Sherburne Stent and other objects removal from a body

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5718973A (en) * 1993-08-18 1998-02-17 W. L. Gore & Associates, Inc. Tubular intraluminal graft
US6017362A (en) * 1994-04-01 2000-01-25 Gore Enterprise Holdings, Inc. Folding self-expandable intravascular stent
US20030055484A1 (en) * 1994-08-31 2003-03-20 Lilip Lau Exterior supported self-expanding stent-graft
US6015429A (en) * 1994-09-08 2000-01-18 Gore Enterprise Holdings, Inc. Procedures for introducing stents and stent-grafts
US20020040236A1 (en) * 1994-09-08 2002-04-04 Gore Enterprise Holdings, Inc. Procedures for introducing stents and stent-grafts
US6843803B2 (en) * 1995-12-01 2005-01-18 Medtronic Vascular, Inc. Bifurcated intraluminal prostheses construction and methods
US6706064B1 (en) * 1997-06-28 2004-03-16 Anson Medical Limited Expandable device
US20040111142A1 (en) * 2000-02-01 2004-06-10 Rourke Jonathan M. Micro-porous mesh stent with hybrid structure
US6733525B2 (en) * 2001-03-23 2004-05-11 Edwards Lifesciences Corporation Rolled minimally-invasive heart valves and methods of use
US20030055495A1 (en) * 2001-03-23 2003-03-20 Pease Matthew L. Rolled minimally-invasive heart valves and methods of manufacture
US20060173537A1 (en) * 2001-03-23 2006-08-03 Jibin Yang Rolled minimally invasive heart valves
US20040210298A1 (en) * 2001-04-27 2004-10-21 Intek Technology, L.L.C. Methods for delivering, repositioning and/or retrieving self-expanding stents
US20060184231A1 (en) * 2005-02-08 2006-08-17 Rucker Brian K Self contracting stent

Also Published As

Publication number Publication date
WO2007024310A3 (fr) 2007-11-29
US9144507B2 (en) 2015-09-29
US20100049237A1 (en) 2010-02-25
WO2007024310A2 (fr) 2007-03-01
WO2007024310A8 (fr) 2008-01-17

Similar Documents

Publication Publication Date Title
US8080053B2 (en) Stent, stent removal and repositioning device, and associated methods
US6447540B1 (en) Stent deployment device including splittable sleeve containing the stent
US6645239B1 (en) Flexible and self-expandable stent and inserting device for such stents
US5356423A (en) Resectable self-expanding stent
AU2002366382B2 (en) Stent delivery apparatus and method
EP1827304B1 (fr) Dispositif de repositionnement et de retrait d'une endoprothese vasculaire
US6620122B2 (en) Gastric pseudocyst drainage and stent delivery system for use therein
KR102080379B1 (ko) 경피 회수가능한 혈관 필터
EP0565542B1 (fr) Element attelle resecable a autodilatation
EP0357003A2 (fr) Endoprothèse expansible radialement
JP2004517648A (ja) 向上した放射方向の拡張性並びに形状記憶性を有する自己拡張型ステント
EP2560590A1 (fr) Stent biodégradable ayant des parties d'extrémité non biodégradables et mécanisme pour l'augmentation de la résistance circulaire de stent
WO2006110565A1 (fr) Stent pour duodenum et procede associe
KR20170118154A (ko) 인입 가능한 앵커를 가진 스텐트
EP2061404B1 (fr) Stent a feuilles multicouche
US20120179238A1 (en) Stent having variable stiffness
EP1680153B1 (fr) Stent realisé en tissus naturels
JP2006055330A (ja) ステント及びステントグラフト
US8814929B2 (en) Stent and stent delivery system for side-branch locations in a conduit
US20070049804A1 (en) One-piece retractable stent
Slepian et al. Urological stents: material, mechanical and functional classification
US20140350657A1 (en) Expandable medical device with an end structure having a transitional surface
JP2017029387A (ja) 生分解性ステント
JP2016146869A (ja) 生分解性ステント

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION