Cold-molding process for loading a stent onto a stent delivery system

Information

  • Patent Grant
  • 9295570
  • Patent Number
    9,295,570
  • Date Filed
    Wednesday, February 23, 2005
    19 years ago
  • Date Issued
    Tuesday, March 29, 2016
    8 years ago
Abstract
A method of making a stent delivery system is provided in which a delivery catheter has a balloon that extends non-uniformly into interstices of a stent. In accordance with the method a balloon/stent/crimping tube assembly is placed in a crimping tool, the balloon is inflated, and the crimping tool is actuated to compress the stent on the outside of the balloon without application of heat or chemicals, thereby causing creases of the balloon to extend non-uniformly into the interstices of the stent. Optionally, pillows may be formed in the balloon to prevent longitudinal movement of the stent with respect to the balloon during intravascular delivery. One or more secondary crimpings also may be performed to achieve a smoother delivery profile.
Description
FIELD OF THE INVENTION

The present invention relates to a cold-molding process for loading a stent onto a stent delivery system. More specifically, the present invention relates to a method of loading a stent onto a balloon having creases that extend non-uniformly into the interstices of the stent without the use of a heating step.


BACKGROUND OF THE INVENTION

A stent is commonly used alone or in conjunction with angioplasty to ensure patency through a patient's stenosed vessel. Stents overcome the natural tendency of the vessel walls of some patients to restenose after angioplasty. A stent is typically inserted into a vessel, positioned across a lesion, and then expanded to create or maintain a passageway through the vessel, thereby restoring near-normal blood flow through the vessel.


A variety of stents are known in the art, including self-expandable and expandable stents, as well as wire braid stents. One such stent is described, for example, in U.S. Pat. No. 4,733,665 to Palmaz. Expandable stents are typically delivered to treatment sites on delivery devices, such as balloon catheters or other expandable devices. Balloon catheters may comprise a balloon having a collapsed delivery configuration with wings that are wrapped and folded about the catheter. An expandable stent is then disposed in a collapsed delivery configuration about the balloon by compressing the stent onto the balloon. The stent and balloon assembly may then be delivered, using well-known percutaneous techniques, to a treatment site within the patient's vasculature, for example, within the patient's coronary arteries. Once the stent is positioned across a lesion at the treatment site, it is expanded to a deployed configuration by inflating the balloon. The stent contacts the vessel wall and maintains a path for blood flow through the vessel.


Significant difficulties have been encountered during stent delivery and deployment, including difficulty in maintaining the stent on the balloon and in achieving symmetrical expansion of the stent when deployed. Several techniques have been developed to more securely anchor the stent to the balloon and to ensure more symmetrical expansion. These include plastically deforming the stent so that it is crimped onto the balloon, and sizing the stent such that its internal diameter provides an interference fit with the outside diameter of the balloon catheter. Such techniques have several drawbacks, including less than optimal securement of the stent to the balloon. Consequently, the stent may become prematurely dislodged from the balloon during advancement of the stent delivery system to the treatment site.


Stent delivery systems utilizing a removable sheath disposed over the exterior surface of the stent, which is removed once the stent is positioned at the treatment site, have also been proposed, for example, in U.S. Pat. No. 5,690,644 to Yurek et al. Such systems may be used with or without retainer rings and are intended to protect the stent during delivery and to provide a smooth surface for easier passage through the patient's vasculature. However, the exterior sheath increases the crossing profile of the delivery system while decreasing flexibility, thereby decreasing the ability of the device to track through narrowed and tortuous anatomy.


U.S. Pat. No. 6,106,530 to Harada describes a stent delivery device comprising a balloon catheter having stoppers disposed proximal and distal of a balloon on to which a stent is affixed for delivery. The stoppers are separate from the balloon and maintain the stent's position in relation to the balloon during delivery. As with the removable sheaths discussed previously, the stoppers are expected to increase delivery profile and decrease flexibility of the stent/balloon system.


U.S. Pat. No. 6,110,180 to Foreman et al. provides a catheter with a balloon having pre-formed, outwardly-extending protrusions on the exterior of the balloon. A stent may be crimped onto the balloon such that the protrusions extend into the gaps of the stent, thereby securing the stent about the balloon for delivery. A drawback to this device is the added complexity involved in manufacturing a balloon with pre-formed protrusions. Additionally, if the protrusions are not formed integrally with the balloon, there is a risk that one or more of the protrusions may detach during deployment of the stent. The protrusions may also reduce flexibility in the delivery configuration, thereby reducing ability to track through tortuous anatomy.


U.S. Pat. No. 5,836,965 to Jendersee et al. describes a hot-molding process for encapsulating a stent on a delivery system. Encapsulation entails placement of the stent over a balloon, placement of a sheath over the stent on the balloon, and heating the pressurized balloon to cause it to expand around the stent within the sheath. The assembly is then cooled while under pressure to cause the balloon to adhere to the stent and to set the shape of the expanded balloon, thereby providing substantially uniform contact between the balloon and the stent. This method also provides a substantially uniform delivery profile along the surface of the encapsulated balloon/stent assembly.


A significant drawback of Jendersee's encapsulation method is the need to heat the balloon in order to achieve encapsulation. Such heating while under pressure may lead to localized plastic flows resulting in inhomogeneities along the length of the balloon including, for example, varying wall thickness. Varying wall thickness may, in turn, yield areas of decreased strength that are susceptible to rupture upon inflation of the balloon during deployment of the stent. Additionally, heating and cooling increases the complexity, time, and cost associated with affixing the stent to the balloon.


U.S. Pat. No. 5,976,181 to Whelan et al. provides an alternative technique for stent fixation involving the use of solvents to soften the balloon material. In this method, the stent is disposed over an evacuated and wrapped balloon while in its compact delivery configuration. A rigid tube is then placed over the stent and balloon assembly, and the balloon is pressurized while the balloon is softened by application of a solvent and/or heating. The rigid tube prevents the stent from expanding but allows the balloon to deform so that its surface projects through either or both of the interstices and ends of the stent. Softening under pressure molds the balloon material such that it takes a permanent set into the stent. Once pressure is removed, the stent is interlocked with the surface of the balloon, providing substantially uniform contact between the balloon and the stent and a substantially uniform delivery profile.


As with the technique in the Jendersee patent, the technique in the Whelan patent has several drawbacks. Chemically softening the balloon material under pressure is expected to introduce inhomogeneities along the length of the balloon, such as varying wall thickness, which again may lead to failure of the balloon. Additionally, chemical alteration of the balloon, via application of a solvent to the surface of the balloon, may unpredictably degrade the mechanical characteristics of the balloon, thereby making accurate and controlled deployment of a stent difficult. Softening also adds cost, complexity, and time to the manufacturing process.


In view of the drawbacks associated with previously known methods and apparatus for loading a stent onto a stent delivery system, it would be desirable to provide methods and apparatus that overcome those drawbacks.


It would be desirable to provide methods and apparatus for loading a stent onto a stent delivery system that enhance positional stability of the stent during delivery.


It would further be desirable to provide methods and apparatus for loading a stent onto a stent delivery system wherein the delivery system comprises a crossing profile and flexibility suitable for use in tortuous and narrowed anatomy.


It would still further be desirable to provide methods and apparatus for loading a stent onto a stent delivery system that provide a substantially symmetrical expansion of the stent at deployment.


It would also be desirable to provide methods and apparatus for loading a stent onto a stent delivery system that do not unpredictably modify the mechanical characteristics of the balloon during fixation of the stent to the balloon.


SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention to provide methods and apparatus for loading a stent onto a stent delivery system and deployment that overcome drawbacks associated with previously known methods and apparatus.


It is an object to provide methods and apparatus for loading a stent onto a stent delivery system that enhance positional stability of the stent during delivery.


It is an object to provide methods and apparatus for loading a stent onto a stent delivery system wherein the delivery system comprises a crossing profile and flexibility suitable for use in tortuous and narrowed anatomy.


It is also an object to provide methods and apparatus for loading a stent onto a stent delivery system that provide a substantially symmetrical expansion of the stent at deployment.


It is an object to provide methods and apparatus for loading a stent onto a stent delivery system that do not unpredictably modify the mechanical characteristics of the balloon during fixation of the stent to the balloon.


These and other objects of the present invention are achieved by providing methods and apparatus for cold-molding a stent to the balloon of a stent delivery system so that the balloon extends non-uniformly into the interstices of the stent. In a preferred embodiment, the stent is a balloon expandable stent and is manufactured in a fully-expanded state or in an intermediate-expanded state (i.e., having a diameter smaller than its fully-expanded, deployed diameter, but larger than its compressed delivery diameter).


The stent is disposed on the balloon of a delivery catheter, and the balloon and stent are placed within an elastic crimping tube. The balloon/stent/crimping tube assembly is then placed in a crimping tool, and the balloon is inflated, preferably only partially. The crimping tool is actuated to compress the stent on the outside of the partially inflated balloon and to cause creases of the balloon to extend non-uniformly into the interstices of the stent. Crimping occurs at a substantially constant temperature, without the use of chemicals. The balloon is then deflated, and the elastic crimping tube is removed.


Optionally, pillows or bumpers may be formed in the proximal and/or distal regions of the balloon during crimping that, in conjunction with the non-uniform creases of the balloon, prevent longitudinal movement of the stent with respect to the balloon during intravascular delivery.


Furthermore, one or more additional, secondary crimping steps may be performed to achieve a smoother delivery profile, in which a semi-rigid crimping tube is disposed over the stent delivery system, and the assembly is again disposed within the crimping tool. During secondary crimping, the crimping tool is actuated to further compress the stent onto the unpressurized balloon. Secondary-crimping may alternatively be performed with the balloon partially or completely pressurized/inflated.


Apparatus of the present invention may be used with a variety of prior art stents, such as balloon expandable stents, and may include tubular slotted stents, connected stents, articulated stents, multiple connected or non-connected stents, and bi-stable stents. In addition to methods of production, methods of using the apparatus of the present invention are provided.





BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the invention, its nature and various advantages will be more apparent from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, in which like reference numerals refer to like parts throughout, and in which:



FIGS. 1A-1C are, respectively, a side view of a stent delivery system in accordance with the present invention, a cross-sectional view of the system along section line A-A in FIG. 1A, and a detail view of the balloon of the system non-uniformly extending within the interstices of the stent;



FIG. 2 is a flow chart showing the steps of the cold-molding process of the present invention;



FIGS. 3A-3C are, respectively, a side view of the distal end of the delivery catheter of the system of FIG. 1 in an expanded configuration, and cross-sectional views of the catheter along section line B-B in FIG. 3A, showing the balloon evacuated to form radially extended wings and in a contracted configuration with the radially extended wings wrapped about the catheter;



FIGS. 4A-4C are, respectively, a side view, partially in section, of the wrapped delivery catheter of FIG. 3C having the stent of FIG. 1 and an elastic crimping tube disposed thereover, the entire assembly disposed within a crimping tool; a cross-sectional view of the same along section line C-C in FIG. 4A; and a detail view of the expandable structure of the stent;



FIGS. 5A and 5B are, respectively, a cross-sectional view along section line C-C in FIG. 4A of the apparatus upon pressurization of the balloon, and a detail view of the expandable structure of the stent;



FIG. 6 is a cross-sectional view along section line C-C in FIG. 4A during crimping after pressure has been removed;



FIG. 7 is a cross-sectional view along section line C-C in FIG. 4A of a possible configuration of the stent delivery system after crimping and removal of the elastic crimping tube;



FIG. 8 is a side view, partially in section, of the stent delivery system disposed within a semi-rigid crimping tube and within the crimping tool for optional secondary crimping; and



FIGS. 9A-9D are side views, partially in section, of the stent delivery system of FIG. 1 disposed within a patient's vasculature, depicting a method of using the apparatus in accordance with the present invention.





DETAILED DESCRIPTION OF THE INVENTION

The present invention comprises methods and apparatus for cold-molding a stent onto a stent delivery system. More specifically, the present invention provides methods and apparatus for obtaining a balloon having creases that extend non-uniformly into the interstices of a stent loaded onto the exterior of the balloon, without the use of a heating or chemical process.


With reference to FIG. 1, apparatus in accordance with the present invention is described. As seen in FIG. 1A, stent delivery system 10, illustratively shown in a collapsed delivery configuration, comprises balloon expandable stent 20 loaded on balloon 14 of delivery catheter 12. Stent 20 comprises an illustrative balloon expandable stent and may be replaced with other stents known in the art. As seen in FIGS. 1B and 1C, balloon 14 has creases 16 that extend non-uniformly into interstices 22 of stent 20.


In FIG. 1B, creases 16 are shown with varying slope and height about the circumference of stent delivery system 10. FIG. 1C depicts creases 16 as shaded areas and illustrates that creases 16 extend along the length of stent 20 within interstices 22. Line L indicates the longitudinal axis of stent 20 in FIG. 1C. It should be understood that creases 16 typically do not extend within every interstice 22 of stent 20.


Delivery catheter 12 preferably includes markers 17 disposed distal of and proximal to stent 20 that facilitate placement of stent 20 on balloon 14, and that facilitate positioning of stent delivery system 10 at a treatment site within a patient's vasculature. Markers 17 are preferably radiopaque and fabricated from a radiopaque material, such as platinum or gold. Catheter 12 preferably also comprises guide wire lumen 13 and inflation lumen 15, which is coupled to balloon 14. As described hereinbelow, during the cold-molding process of the present invention, proximal and/or distal pillows 19 optionally may be formed in balloon 14 during pressurized crimping. As with creases 16, pillows 19 act to reduce or prevent longitudinal movement of the stent on the balloon during intravascular delivery.


Balloon 14 is expandable by injection of a suitable medium, such as air or saline, via inflation lumen 15. Balloon 14 preferably expands stent 20 to a deployed configuration under application of pressure in the range of about 6-9 atm. Additionally, balloon 14 preferably has a rated burst pressure above 10 atm, and even more preferably between about 12-14 atm. Balloon 14 may be fabricated from a variety of materials, including Nylon, polyethylene terephalate, polyethylene, and polyether/polyamide block copolymers, such as PEBAX.


Additionally, balloon 14 may be fabricated from an elastomeric polyester block copolymer having an aromatic polyester hard segment and an aliphatic polyester soft segment, such as “Pelprene,” which is marketed by the Toyobo Corporation of Osaka, Japan. Balloon 14 also may be fabricated from a copolymer having a polybutylene terephalate hard segment and a long chain of polyether glycol soft segment, such as “Hytrel” from the DuPont Corporation of Wilmington, Del.


Illustrative stent 20 may be fabricated from a variety of materials, including polymers and metals, and may comprise any of a variety of prior art stents, such as balloon expandable stents, including tubular slotted stents, connected stents, articulated stents, multiple connected or non-connected stents, and bi-stable stents. Stent 20 also may include external coating C configured to retard restenosis or thrombus formation in the vessel region surrounding the stent. Alternatively, coating C may deliver therapeutic agents into-the-patient's blood stream or vessel wall.


Referring now to FIGS. 2-8, a method of producing stent delivery system 10 is described. FIG. 2 provides an overview of the cold-molding process of the present invention, while FIGS. 3-8 provide detailed views of these process steps.


As depicted in FIG. 2, the cold-molding process of the present invention involves steps of: obtaining a stent, step 102; obtaining a balloon catheter, step 103; disposing the stent on the balloon of the balloon catheter, step 104; and disposing an elastic crimping sleeve over the stent and balloon, step 105. In accordance with the method of the present invention, the balloon is then inflated—preferably only partially—with an inflatable medium, such as air, at step 106. The sleeve/stent/balloon assembly is then crimped within a crimping tool that compresses the stent onto the balloon, step 107, while the balloon is pressurized.


As described hereinbelow, this step causes the balloon to bulge into the interstices of the stent, and in addition, to form pillows 19, proximal of, and distal to, the ends of the stent to retain the stent in place during transluminal delivery. At step 108, the balloon is depressurized, and the elastic sleeve is removed to complete the stent loading process.


If desired, a semi-rigid sleeve optionally may be disposed over the stent/balloon assembly, and one or more additional crimping steps may be performed, steps 109 and 110 of FIG. 2.


Referring now to FIGS. 3-8, additional details of a preferred embodiment of the process of the present invention are illustrated and described. In FIG. 3, balloon 14 of delivery catheter 12 preferably is folded prior to placement of stent 20 about balloon 14. Balloon 14 is first expanded, as in FIG. 3A, and then evacuated to form radially extended wings 18, as seen in FIG. 3B. Balloon 14 is illustratively depicted with four wings 18, but it should be understood that any number of wings may be provided, for example, two, three or five wings. In FIG. 3C, wings 18 are wrapped about the shaft of delivery catheter 12 to dispose catheter 12 in a contracted configuration. It should be understood that balloon 14 may alternatively be folded and/or disposed in a collapsed delivery configuration by other techniques, for example, with techniques that do not utilize wings.


With reference to FIG. 4, stent 20 and elastic crimping tube 30 are disposed about balloon 14, preferably with stent 20 positioned between markers 17 of delivery catheter 12 (steps 102-105, FIG. 2). The balloon/stent/crimping tube assembly is inserted within crimping tool 40, as seen in FIG. 4A. Crimping tool 40 is preferably positioned between markers 17 to facilitate formation of optional pillows 19 during pressurization of balloon 14. Crimping tool 40 may be any of a variety of crimping tools known in the art. An illustrative crimping tool is described, for example, in U.S. Pat. No. 6,082,990 to Jackson et al., which is incorporated herein by reference.


Referring to FIG. 4B, stent 20 may be directly placed about balloon 14, and elastic crimping tube 30 then may be loaded over the stent/balloon assembly. Alternatively, stent 20 may be placed within elastic crimping tube 30, and then the stent/tube assembly disposed surrounding balloon 14. As yet another alternative, crimping tube 30, or crimping tube 30 and stent 20, may be positioned within crimping tool 40; then, balloon 14, with or without stent 20 loaded thereon, may be positioned within crimping tool 40.


As depicted in FIG. 4C, stent 20 preferably is manufactured in an intermediate-expanded state having a diameter smaller than its expanded deployed diameter, but larger than its compressed delivery diameter, thereby facilitating positioning of stent 20 about balloon 14. When stent 20 is initially disposed surrounding balloon 14, the balloon does not substantially extend into interstices 22 of stent 20. It should be understood that stent 20 alternatively may be manufactured in a fully-expanded state.


In FIG. 5, once stent 20 and crimping tube 30 are disposed about balloon 14 of delivery catheter 12, and once the entire assembly is disposed within crimping tool 40, balloon 14 is pressurized, for example, via an inflation medium delivered through inflation lumen 15 of catheter 12 (step 106, FIG. 2). Pressure application causes balloon 14 to enter a portion of interstices 22 of stent 20 in a non-uniform manner, as seen in the cross section of FIG. 5A and in the detail view of FIG. 5B. Crimping tube 30 and crimping tool 40 prevent expansion of stent 20 during partial or complete pressurization of balloon 14, as depicted in FIG. 5A.


The inflation medium is preferably delivered at a pressure in the range of about 6-8 atm. This pressure range is below the preferred rated burst pressure of balloon 14, which is above 10 atm, and even more preferably between about 12-14 atm, and thus ensures that the balloon does not puncture. The elasticity of crimping tube 30 allows the tube to expand slightly upon application of pressure, and to contract slightly during crimping. Tube 30 may be fabricated from any suitable elastic material, for example, a polymer, such as PEBAX. Elastic crimping tube 30 preferably has a hardness of between about 30 and 40 Shore Hardness, and more preferably a hardness of about 35 Shore Hardness.


With reference to FIG. 6, in conjunction with FIG. 4A, crimping tool 40 is actuated to crimp stent 20 onto balloon 14 (step 107, FIG. 2). Crimping tool 40 applies an inwardly-directed stress, σcrimp, to the assembly. Initially, balloon 14 is still pressurized. Stent 20 is compressed onto the outside of balloon 14, causing the balloon to further bulge non-uniformly into interstices 22 of the stent. Crimping preferably proceeds along the length of the balloon/stent/tube assembly all at once but may alternatively proceed in sections, so that the assembly is gradually crimped along its length.


Balloon 14 is then depressurized, allowing crimping tool 40 to further compress stent 20 onto balloon 14, as seen in FIG. 6 (step 108, FIG. 2), which forms creases 16 of balloon 14 that extend non-uniformly within interstices 22 of the stent. Creases 16 are most clearly seen in FIGS. 1B and 1C. Optional pillows 19 of stent delivery system 10 are also formed. Since many prior art crimping tools 40 apply an inwardly-directed stress, σcrimp, that is not uniform about the radius of balloon 14, elastic crimping tube 30 acts to more uniformly distribute the stress about the circumference of the balloon/stent assembly.


Stent delivery system 10 is removed from elastic crimping tube 30 and crimping tool 40 (step 108, FIG. 2). Stent delivery system 10 has a low-profile delivery configuration adapted for percutaneous delivery within a patient's vasculature, as described hereinbelow with respect to FIG. 9. Creases 16, as well as pillows 19, secure stent 20 to balloon 14 between markers 17 of delivery catheter 12.


In contrast to prior art techniques described hereinabove, crimping in accordance with the present invention occurs at a substantially constant temperature, without the use of chemicals. In the context of the present invention, substantially constant temperature during crimping should be understood to include minor fluctuations in the actual temperature due to frictional losses, etc.


Importantly, the system of the present invention is not actively heated to thermally remodel the balloon, as described in U.S. Pat. No. 5,836,965 to Jendersee et al. Likewise, no solvents are added to soften and mold the balloon, as described in U.S. Pat. No. 5,976,181 to Whelan et al. As described previously, both heating and solvents have significant potential drawbacks, including inhomogeneities along the length of the balloon, such as varying wall thickness. Varying wall thickness may yield areas of decreased strength that are susceptible to rupture upon inflation of the balloon during deployment of the stent. Additionally, heating and cooling, as well as addition of solvents, increases the complexity, time, and cost associated with affixing the stent to the balloon.


Theoretical bounds for the radial stress that may be applied to balloon 14 during crimping, while the balloon is pressurized, may be estimated by modeling balloon 14 as an idealized tube and assuming crimping tool 40 applies an evenly distributed, inwardly-directed radial stress, σcrimp. Stent 20 and elastic crimping tool 30, meanwhile, theoretically resist the crimping stress with an outwardly-directed radial stress, σresistance. Thus, the composite inwardly-directed radial stress, σin, applied to balloon 14 may be idealized as:

σincrimp−σresistance  (1)

Pressurization/inflation of balloon 14 similarly may be modeled as an evenly distributed, outwardly-directed radial stress, σo and it may be assumed that the rated burst pressure of balloon 14 is the yield stress of the balloon, σy. A stress balance provides:

σin−σouty  (2)

Thus, a theoretical upper bound for the radial stress, σin, that may be applied to balloon 14 is:

σinyout  (3)

A theoretical lower bound for σin also may be found by observing that, in order to compress stent 20 onto the exterior of balloon 14, crimping tool 40 must apply a radial stress, σcrimp, that is greater than the net stress provided by resistance of stent 20 and crimping tube 30, σresistance, and by the inflation of balloon 14, σout:

σcrimpoutresistance  (4)

Combining Equation (1) and (4) provides a lower bound for σin:

σinout  (5)

Finally, combining Equations (3) and (5) provides a range for σin:

σoutinyout  (6)


As an example, assuming a burst pressure, σy, of 12 atm and a balloon pressurization, σout, of 8 atm, the balloon will theoretically withstand an inwardly-directed stress, σin, of up to 20 atm. Furthermore, in order to ensure that stent 20 is crimped onto balloon 14, σin must be greater than 8 atm. Thus, the inwardly-directed radial stress must be between 8 and 20 atm. Assuming, for example, a resistance stress, σresistance, of 2 atm, crimping tool 40 must apply a crimping stress, σcrimp, between 10 and 22 atm. As one of ordinary skill will readily understand, the actual radial stress applied should be further optimized within this range to provide a safety factor, optimal crimping, etc. Since balloon 14 is not in reality an idealized tube, stresses applied to the balloon will have a longitudinal component in addition to the radial component, which may be, for example, accounted for in the safety factor.


With reference now to FIG. 7, a possible configuration of the stent delivery system after crimping and removal of elastic crimping tube 30 is described. One or more struts 21 of stent 20 may be incompletely compressed against balloon 14. Such a strut may potentially snag against the patient's vasculature during delivery, and thereby prevent positioning of stent delivery system 10 at a treatment site. Additionally, pressurized crimping may result in a delivery profile for delivery system 10 that is more polygonal than cylindrical, thereby applying undesirable stresses on the vessel wall during transluminal insertion. Accordingly, it may be desirable to perform an optional secondary crimping step after balloon 14 has been depressurized.


Referring to FIG. 8, in order to reduce the potential for incompletely compressed individual struts 21 of stent 20, and to provide a more uniform cylindrical delivery profile, one or more additional, secondary crimping steps may be performed on stent delivery system 10. In FIG. 8, stent delivery system 10 is disposed within semi-rigid crimping tube 50, which is disposed within crimping tool 40 (step 109, FIG. 2). Tube 50 may be fabricated from any suitable semi-rigid material. As with elastic crimping tube 30, semi-rigid crimping tube 50 preferably comprises a polymer, such as PEBAX. Semi-rigid crimping tube 50 preferably has a hardness of between about 50 and 60 Shore Hardness, and more preferably a hardness of about 55 Shore Hardness.


With stent delivery system 10 disposed within semi-rigid tube 50 and crimping tool 40, tool 40 is actuated to compress individual struts 21 against balloon 14 and to give delivery system 10 the substantially cylindrical delivery profile of FIG. 1B (step 110, FIG. 2). As with elastic crimping tube 30, semi-rigid tube 50 acts to evenly distribute crimping stresses applied by crimping tool 40 around the circumference of the stent/balloon assembly. Since balloon 14 is not pressurized, secondary crimping preferably proceeds in sections along the length of stent delivery system 10. However, as will be apparent to those of skill in the art, secondary crimping may proceed in one step. Optionally, balloon 14 may be pressurized during secondary crimping.


Referring now to FIG. 9, a method of using stent delivery system 10 of the present invention is described. Stent delivery system 10 is disposed in a contracted delivery configuration with stent 20 disposed over balloon 14 of delivery catheter 12. Creases 16 of balloon 14 non-uniformly extend within interstices 22 of stent 20. Creases 16, in conjunction with optional pillows 19, act to secure stent 20 to balloon 14. As seen in FIG. 9A, the distal end of catheter 12 is delivered to a target site T within a patient's vessel V using, for example, well-known percutaneous techniques. Target site T may, for example, comprise a stenosed region of vessel V. The radiopacity of markers 17 may facilitate positioning of system 10 at the target site. Alternatively, stent 20 or other portions of catheter 12 may be radiopaque to facilitate positioning.


In FIG. 9B, balloon 14 is inflated, for example, via an inflation medium delivered through inflation lumen 15 of catheter 12. Stent 20 expands to the deployed configuration in which it contacts the wall of vessel V at target site T. Expansion of stent 20 opens interstices 22 of the stent and removes the non-uniform creases of balloon 14 from within the interstices. Additionally, stent 20 has a diameter in the deployed configuration that is larger than the diameter of optional pillows 19, thereby facilitating removal of stent 20 from delivery catheter 12. Balloon 14 is then deflated, as seen in FIG. 9C, and delivery catheter 12 is removed from vessel V, as seen in FIG. 9D.


Stent 20 remains in place within vessel V in the deployed configuration in order to reduce restenosis and recoil of the vessel. Stent 20 also may comprise external coating C configured to retard restenosis or thrombus formation around the stent. Alternatively, coating C may deliver therapeutic agents into the patient's blood stream or a portion of the vessel wall adjacent to the stent.


Although preferred illustrative embodiments of the present invention are described hereinabove, it will be evident to those skilled in the art that various changes and modifications may be made therein without departing from the invention.


For example, stent delivery system 10 may be produced without using elastic crimping tube 30. In this case, the stent/balloon assembly would be loaded directly into crimping tool 40, which would limit expansion of balloon 14 during pressurization. Likewise, semi-rigid crimping tube 50 may be eliminated from the secondary crimping procedure. If crimping tubes are not used, crimping tool 40 preferably applies an inwardly-directed stress that is substantially evenly distributed about the circumference of the stent/balloon assembly.


Additionally, balloon 14 may be depressurized prior to crimping stent 20 onto the balloon. This may be particularly beneficial when crimping long stents, for example, stents longer than about 50 mm. Pressurization of balloon 14 may cause the balloon to increase in longitudinal length. When crimping a long stent 20 onto a correspondingly long balloon 14, this increase in balloon length is expected to be more significant, for example, greater than about 1 mm.


If stent 20 is crimped onto balloon 14 while the balloon is pressured, significant stresses may be encountered along creases 16 after balloon 14 is depressurized, due to contraction of the balloon back to its shorter, un-inflated longitudinal length. These stresses may, in turn, lead to pinhole perforations of balloon 14. Thus, since pressurization of balloon 14 causes the balloon to extend at least partially within interstices 22 of stent 20 in a non-uniform manner, as seen in FIG. 5A, it is expected that crimping after depressurization will still establish creases 16 of stent delivery system 10, in accordance with the present invention. Obviously, crimping after depressurization may be done with stents 20 of any length, not just long stents.


It is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.

Claims
  • 1. A stent delivery system having a contracted delivery configuration and an expanded deployed configuration, the stent delivery system comprising: a stent having a plurality of expandable elements and a plurality of interstices disposed between adjacent expandable elements; anda delivery catheter having an inflatable balloon comprising creases extending non-uniformly within the interstices of the stent in the contracted delivery configuration, each crease defining a maximum radial height within a corresponding interstice, wherein the maximum radial heights of the creases vary;wherein the stent delivery system is made by: introducing an inflation medium into the balloon;compressing the stent to an intermediate configuration using a crimping tool;releasing at least a portion of the inflation medium from the balloon; andcompressing the stent to the contracted delivery configuration.
  • 2. The stent delivery system of claim 1, wherein the stent comprises a metal stent.
  • 3. The stent delivery system of claim 1, wherein the stent comprises a polymer stent.
  • 4. The stent delivery system of claim 1, wherein the stent comprises an external coating.
  • 5. The stent delivery system of claim 1, wherein introducing an inflation medium into the balloon comprises partially inflating the balloon.
  • 6. The stent delivery system of claim 1, wherein the stent delivery system is made by re-inflating the balloon after releasing at least a portion of the inflation medium from the balloon.
  • 7. The stent delivery system of claim 1, wherein the creases include a folded first region having at least one fold of the balloon folded into at least an interstice and a second folded region having a least two folds of the balloon folded into at least a second interstice, wherein the creases are captured within the interstices to releasably affix the stent to the inflatable balloon.
  • 8. The stent delivery system of claim 1, wherein introducing the inflation medium into the balloon comprises introducing the inflation medium at a pressure in the range of about 6 atm to about 8 atm.
  • 9. The stent delivery system of claim 1, wherein the balloon has a working length and is free from heat-induced and solvent-induced inhomogeneities along the working length of the balloon.
  • 10. The stent delivery system of claim 1, wherein the creases have varying slope about a circumference of the stent delivery system.
  • 11. The stent delivery system of claim 1, wherein a first crease corresponding to a first interstice has a first maximum radial height greater than a radial midpoint of the first interstice and a second crease corresponding to a second interstice has a second maximum radial height less than a radial midpoint of the second interstice.
  • 12. A method for stenting at a target site within a patient's vessel, the method comprising: providing a stent delivery system comprising a stent having a plurality of expandable elements and a plurality of interstices disposed between adjacent expandable elements and a delivery catheter with an inflatable cold-molded balloon having creases extending non-uniformly within the interstices of the stent, each crease defining a maximum radial height within a corresponding interstice, wherein the maximum radial heights of the creases vary, wherein the stent delivery system is made by: introducing an inflation medium into the balloon;compressing the stent to an intermediate configuration using a crimping tool;releasing at least a portion of the inflation medium from the balloon; andcompressing the stent to a contracted delivery configuration;percutaneously delivering the stent delivery system to the target site within the patient's vessel in the contracted delivery configuration; andexpanding the stent delivery system to an expanded deployed configuration, wherein the balloon is inflated, the interstices of the stent open, and the stent engages the target site.
  • 13. The method of claim 12, wherein introducing an inflation medium into the balloon comprises partially inflating the balloon.
  • 14. The method of claim 12, wherein the stent delivery system is made by re-inflating the balloon after releasing at least a portion of the inflation medium from the balloon.
  • 15. The method of claim 12, wherein the stent delivery system is made by loading the stent and the delivery catheter into the crimping tool.
  • 16. The method of claim 12, wherein introducing an inflation medium into the balloon comprises introducing the inflation medium at a pressure below a burst pressure of the balloon.
  • 17. The method of claim 12, wherein introducing an inflation medium into the balloon comprises introducing an inflation medium at a pressure in the range of about 6 atm to about 8 atm.
  • 18. The method of claim 12, wherein compressing the stent to a contracted delivery configuration comprises compressing the stent in sections along a length of the stent.
  • 19. The method of claim 12, wherein the stent delivery system is made by performing one or more additional crimping steps to further compress the stent.
  • 20. The method of claim 12, wherein the stent delivery system is made without applying heat or chemicals to the balloon.
  • 21. The method of claim 12, wherein the stent is disposed about the balloon, and the creases include a first folded region having at least one fold of the balloon folded into at least a first interstice and a second folded region having at least two folds of the balloon folded into at least a second interstice, and wherein the creases are captured within the interstices to releasably affix the stent to the inflatable balloon.
  • 22. The method of claim 12, further comprising: deflating the balloon; andremoving the delivery catheter from the patient's vessel.
  • 23. The method of claim 12, wherein the balloon has a working length and is free from heat-induced and solvent-induced inhomogeneities along the working length of the balloon.
  • 24. The method of claim 12, wherein the creases have varying slope about a circumference of the stent delivery system.
  • 25. The method of claim 12, wherein a first crease corresponding to a first interstice has a first maximum radial height greater than a radial midpoint of the first interstice and a second crease corresponding to a second interstice has a second maximum radial height less than a radial midpoint of the second interstice.
Parent Case Info

This application is a divisional of U.S. patent application Ser. No. 09/957,216, filed Sep. 19, 2001, now U.S. Pat. No. 6,863,683, the full disclosure of which is incorporated herein by reference.

US Referenced Citations (425)
Number Name Date Kind
3687135 Stroganov et al. Aug 1972 A
3839743 Schwarcz Oct 1974 A
3900632 Robinson Aug 1975 A
4104410 Malecki Aug 1978 A
4110497 Hoel Aug 1978 A
4321711 Mano Mar 1982 A
4346028 Griffith Aug 1982 A
4596574 Urist Jun 1986 A
4599085 Riess et al. Jul 1986 A
4612009 Drobnik et al. Sep 1986 A
4633873 Dumican et al. Jan 1987 A
4656083 Hoffman et al. Apr 1987 A
4718907 Karwoski et al. Jan 1988 A
4722335 Vilasi Feb 1988 A
4723549 Wholey et al. Feb 1988 A
4732152 Wallsten et al. Mar 1988 A
4733665 Palmaz Mar 1988 A
4739762 Palmaz Apr 1988 A
4740207 Kreamer Apr 1988 A
4743252 Martin, Jr. et al. May 1988 A
4768507 Fischell et al. Sep 1988 A
4776337 Palmaz Oct 1988 A
4800882 Gianturco Jan 1989 A
4816339 Tu et al. Mar 1989 A
4818559 Hama et al. Apr 1989 A
4850999 Planck Jul 1989 A
4877030 Beck et al. Oct 1989 A
4878906 Lindemann et al. Nov 1989 A
4879135 Greco et al. Nov 1989 A
4886062 Wiktor Dec 1989 A
4902289 Yannas Feb 1990 A
4977901 Ofstead Dec 1990 A
4990151 Wallsten Feb 1991 A
4994298 Yasuda Feb 1991 A
5019090 Pinchuk May 1991 A
5028597 Kodama et al. Jul 1991 A
5059211 Stack et al. Oct 1991 A
5062829 Pryor et al. Nov 1991 A
5084065 Weldon et al. Jan 1992 A
5085629 Goldberg et al. Feb 1992 A
5087244 Wolinsky et al. Feb 1992 A
5100429 Sinofsky et al. Mar 1992 A
5104410 Chowdhary Apr 1992 A
5108417 Sawyer Apr 1992 A
5112457 Marchant May 1992 A
5123917 Lee Jun 1992 A
5147385 Beck et al. Sep 1992 A
5156623 Hakamatsuka et al. Oct 1992 A
5163951 Pinchuk et al. Nov 1992 A
5163952 Froix Nov 1992 A
5163958 Pinchuk Nov 1992 A
5167614 Tessmann et al. Dec 1992 A
5192311 King et al. Mar 1993 A
5197977 Hoffman, Jr. et al. Mar 1993 A
5234456 Silvestrini Aug 1993 A
5234457 Andersen Aug 1993 A
5236447 Kubo et al. Aug 1993 A
5279594 Jackson Jan 1994 A
5282860 Matsuno et al. Feb 1994 A
5289831 Bosley Mar 1994 A
5290271 Jernberg Mar 1994 A
5292321 Lee Mar 1994 A
5306286 Stack et al. Apr 1994 A
5306294 Winston et al. Apr 1994 A
5328471 Slepian Jul 1994 A
5330500 Song Jul 1994 A
5342348 Kaplan Aug 1994 A
5342395 Jarrett et al. Aug 1994 A
5342621 Eury Aug 1994 A
5356433 Rowland et al. Oct 1994 A
5383925 Schmitt Jan 1995 A
5385580 Schmitt Jan 1995 A
5389106 Tower Feb 1995 A
5399666 Ford Mar 1995 A
5423885 Williams Jun 1995 A
5441515 Khosravi et al. Aug 1995 A
5443458 Eury et al. Aug 1995 A
5443500 Sigwart Aug 1995 A
5455040 Marchant Oct 1995 A
5464650 Berg et al. Nov 1995 A
5502158 Sinclair et al. Mar 1996 A
5507768 Lau et al. Apr 1996 A
5514154 Lau et al. May 1996 A
5514379 Weissieder et al. May 1996 A
5527337 Stack et al. Jun 1996 A
5545208 Wolff et al. Aug 1996 A
5545408 Trigg et al. Aug 1996 A
5549635 Solar Aug 1996 A
5554120 Chen et al. Sep 1996 A
5556413 Lam Sep 1996 A
5569295 Lam Oct 1996 A
5578046 Liu et al. Nov 1996 A
5578073 Haimovich et al. Nov 1996 A
5591199 Porter et al. Jan 1997 A
5591607 Gryaznov et al. Jan 1997 A
5593403 Buscemi Jan 1997 A
5593434 Williams Jan 1997 A
5599301 Jacobs et al. Feb 1997 A
5599922 Gryaznov et al. Feb 1997 A
5605696 Eury et al. Feb 1997 A
5607442 Fischell et al. Mar 1997 A
5607467 Froix Mar 1997 A
5618299 Khosravi et al. Apr 1997 A
5628784 Strecker May 1997 A
5629077 Turnlund et al. May 1997 A
5631135 Gryaznov et al. May 1997 A
5632771 Boatman et al. May 1997 A
5632840 Campbell May 1997 A
5637113 Tartaglia et al. Jun 1997 A
5649977 Campbell Jul 1997 A
5667767 Greff et al. Sep 1997 A
5667796 Otten Sep 1997 A
5670558 Onishi et al. Sep 1997 A
5690644 Yurek et al. Nov 1997 A
5693085 Buirge et al. Dec 1997 A
5700286 Tartaglia et al. Dec 1997 A
5707385 Williams Jan 1998 A
5711763 Nonami et al. Jan 1998 A
5716393 Lindenberg et al. Feb 1998 A
5716981 Hunter et al. Feb 1998 A
5725549 Lam Mar 1998 A
5726297 Gryaznov et al. Mar 1998 A
5728068 Leone et al. Mar 1998 A
5728751 Patnaik Mar 1998 A
5733326 Tomonto et al. Mar 1998 A
5733330 Cox Mar 1998 A
5733564 Lehtinen Mar 1998 A
5733925 Kunz et al. Mar 1998 A
5741881 Patnaik Apr 1998 A
5756457 Wang et al. May 1998 A
5756476 Epstein et al. May 1998 A
5759474 Rupp et al. Jun 1998 A
5765682 Bley et al. Jun 1998 A
5766204 Porter et al. Jun 1998 A
5766239 Cox Jun 1998 A
5766710 Turnlund et al. Jun 1998 A
5769883 Buscemi et al. Jun 1998 A
5776140 Cottone Jul 1998 A
5780807 Saunders Jul 1998 A
5782839 Hart et al. Jul 1998 A
5792144 Fischell et al. Aug 1998 A
5800516 Fine et al. Sep 1998 A
5811447 Kunz et al. Sep 1998 A
5824049 Ragheb et al. Oct 1998 A
5830178 Jones et al. Nov 1998 A
5830461 Billiar Nov 1998 A
5830879 Isner Nov 1998 A
5833651 Donovan et al. Nov 1998 A
5834582 Sinclair et al. Nov 1998 A
5836962 Gianotti Nov 1998 A
5836965 Jendersee et al. Nov 1998 A
5837313 Ding et al. Nov 1998 A
5837835 Gryaznov et al. Nov 1998 A
5840083 Braach-Maksvytis Nov 1998 A
5851508 Greff et al. Dec 1998 A
5853408 Muni Dec 1998 A
5854207 Lee et al. Dec 1998 A
5855612 Ohthuki et al. Jan 1999 A
5855618 Patnaik et al. Jan 1999 A
5858746 Hubbell et al. Jan 1999 A
5860966 Tower Jan 1999 A
5865814 Tuch Feb 1999 A
5868781 Killion Feb 1999 A
5871468 Kramer et al. Feb 1999 A
5873904 Ragheb et al. Feb 1999 A
5874101 Zhong et al. Feb 1999 A
5874109 Ducheyne et al. Feb 1999 A
5874165 Drumheller Feb 1999 A
5876743 Ibsen et al. Mar 1999 A
5877263 Patnaik et al. Mar 1999 A
5879713 Roth et al. Mar 1999 A
5888533 Dunn Mar 1999 A
5891192 Murayama et al. Apr 1999 A
5893852 Morales Apr 1999 A
5897955 Drumheller Apr 1999 A
5906759 Richter May 1999 A
5913871 Werneth et al. Jun 1999 A
5914182 Drumheller Jun 1999 A
5916870 Lee et al. Jun 1999 A
5920975 Morales Jul 1999 A
5922005 Richter et al. Jul 1999 A
5942209 Leavitt et al. Aug 1999 A
5948428 Lee et al. Sep 1999 A
5954744 Phan et al. Sep 1999 A
5957975 Lafont et al. Sep 1999 A
5965720 Gryaznov et al. Oct 1999 A
5971954 Conway et al. Oct 1999 A
5976181 Whelan et al. Nov 1999 A
5976182 Cox Nov 1999 A
5980530 Willard et al. Nov 1999 A
5980564 Stinson Nov 1999 A
5980928 Terry Nov 1999 A
5980972 Ding Nov 1999 A
5981568 Kunz et al. Nov 1999 A
5986169 Gjunter Nov 1999 A
5997468 Wolff et al. Dec 1999 A
6010445 Armini et al. Jan 2000 A
6015541 Greff et al. Jan 2000 A
6022359 Frantzen Feb 2000 A
6042875 Ding et al. Mar 2000 A
6048964 Lee et al. Apr 2000 A
6051648 Rhee et al. Apr 2000 A
6056993 Leidner et al. May 2000 A
6060451 DiMaio et al. May 2000 A
6063092 Shin May 2000 A
6066156 Yan May 2000 A
6071266 Kelley Jun 2000 A
6074381 Dinh et al. Jun 2000 A
6074659 Kunz et al. Jun 2000 A
6080177 Igaki et al. Jun 2000 A
6080488 Hostettler et al. Jun 2000 A
6082990 Jackson et al. Jul 2000 A
6083258 Yadav Jul 2000 A
6093463 Thakrar Jul 2000 A
6096070 Ragheb et al. Aug 2000 A
6096525 Patnaik Aug 2000 A
6099562 Ding et al. Aug 2000 A
6103230 Billiar et al. Aug 2000 A
6106530 Harada Aug 2000 A
6107416 Patnaik et al. Aug 2000 A
6110180 Foreman et al. Aug 2000 A
6110188 Narciso, Jr. Aug 2000 A
6113629 Ken Sep 2000 A
6117979 Hendriks et al. Sep 2000 A
6120522 Vrba et al. Sep 2000 A
6120536 Ding et al. Sep 2000 A
6120904 Hostettler et al. Sep 2000 A
6121027 Clapper et al. Sep 2000 A
6125523 Brown et al. Oct 2000 A
6127173 Eckstein et al. Oct 2000 A
6129761 Hubbell Oct 2000 A
6129928 Sarangapani et al. Oct 2000 A
6141855 Morales Nov 2000 A
6150630 Perry et al. Nov 2000 A
6153252 Hossainy et al. Nov 2000 A
6159227 Di Caprio et al. Dec 2000 A
6159951 Karpeisky et al. Dec 2000 A
6160084 Langer et al. Dec 2000 A
6165212 Dereume et al. Dec 2000 A
6166130 Rhee et al. Dec 2000 A
6169170 Gryaznov et al. Jan 2001 B1
6171609 Kunz Jan 2001 B1
6174330 Stinson Jan 2001 B1
6177523 Reich et al. Jan 2001 B1
6183505 Mohn, Jr. et al. Feb 2001 B1
6187045 Fehring et al. Feb 2001 B1
6210715 Starling et al. Apr 2001 B1
6224626 Steinke May 2001 B1
6228845 Donovan et al. May 2001 B1
6240616 Yan Jun 2001 B1
6245076 Yan Jun 2001 B1
6245103 Stinson Jun 2001 B1
6248344 Yianen et al. Jun 2001 B1
6251135 Stinson et al. Jun 2001 B1
6251142 Bernacca et al. Jun 2001 B1
6264683 Stack et al. Jul 2001 B1
6267776 O'Connell Jul 2001 B1
6273913 Wright et al. Aug 2001 B1
6280412 Pederson et al. Aug 2001 B1
6281262 Shikinami Aug 2001 B1
6284333 Wang et al. Sep 2001 B1
6287332 Bolz et al. Sep 2001 B1
6290721 Heath Sep 2001 B1
6293966 Frantzen Sep 2001 B1
6296655 Gaudoin et al. Oct 2001 B1
6303901 Perry et al. Oct 2001 B1
6312459 Huang et al. Nov 2001 B1
6327772 Zadno-Azizi et al. Dec 2001 B1
6352547 Brown et al. Mar 2002 B1
6375660 Fischell et al. Apr 2002 B1
6375826 Wang et al. Apr 2002 B1
6379381 Hossainy et al. Apr 2002 B1
6387121 Alt May 2002 B1
6388043 Langer et al. May 2002 B1
6395326 Castro et al. May 2002 B1
6409761 Jang Jun 2002 B1
6423092 Datta et al. Jul 2002 B2
6461632 Gogolewski Oct 2002 B1
6464720 Boatman et al. Oct 2002 B2
6479565 Stanley Nov 2002 B1
6481262 Ching et al. Nov 2002 B2
6485512 Cheng Nov 2002 B1
6492615 Flanagan Dec 2002 B1
6494908 Huxel et al. Dec 2002 B1
6495156 Wenz et al. Dec 2002 B2
6510722 Ching et al. Jan 2003 B1
6511748 Barrows Jan 2003 B1
6517559 O'Connell Feb 2003 B1
6517888 Weber Feb 2003 B1
6527801 Dutta Mar 2003 B1
6537589 Chae et al. Mar 2003 B1
6539607 Fehring et al. Apr 2003 B1
6540777 Stenzel Apr 2003 B2
6551303 Van Tassel et al. Apr 2003 B1
6554854 Flanagan Apr 2003 B1
6565599 Hong et al. May 2003 B1
6569191 Hogan May 2003 B1
6569193 Cox et al. May 2003 B1
6572672 Yadav et al. Jun 2003 B2
6574851 Mirizzi Jun 2003 B1
6579305 Lashinski Jun 2003 B1
6585755 Jackson et al. Jul 2003 B2
6592614 Lenker et al. Jul 2003 B2
6592617 Thompson Jul 2003 B2
6613072 Lau et al. Sep 2003 B2
6626939 Burnside et al. Sep 2003 B1
6635269 Jennissen Oct 2003 B1
6645243 Vallana et al. Nov 2003 B2
6656162 Santini, Jr. et al. Dec 2003 B2
6664335 Krishnan Dec 2003 B2
6666214 Canham Dec 2003 B2
6667049 Janas et al. Dec 2003 B2
6669723 Killion et al. Dec 2003 B2
6676697 Richter Jan 2004 B1
6679980 Andreacchi Jan 2004 B1
6689375 Wahlig et al. Feb 2004 B1
6695920 Pacetti et al. Feb 2004 B1
6706273 Roessier Mar 2004 B1
6709379 Brandau et al. Mar 2004 B1
6719934 Stinson Apr 2004 B2
6719989 Matsushima et al. Apr 2004 B1
6720402 Langer et al. Apr 2004 B2
6745445 Spilka Jun 2004 B2
6746773 Llanos et al. Jun 2004 B2
6752826 Holloway et al. Jun 2004 B2
6753007 Haggard et al. Jun 2004 B2
6764504 Wang et al. Jul 2004 B2
6764505 Hossainy et al. Jul 2004 B1
6769161 Brown et al. Aug 2004 B2
6818063 Kerrigan Nov 2004 B1
6846323 Yip et al. Jan 2005 B2
6863683 Schwager et al. Mar 2005 B2
7008446 Amis et al. Mar 2006 B1
7347869 Hojeibane et al. Mar 2008 B2
7470281 Tedeschi Dec 2008 B2
7563400 Wilson et al. Jul 2009 B2
7722663 Austin May 2010 B1
7731740 LaFont et al. Jun 2010 B2
7763198 Knott et al. Jul 2010 B2
7776926 Hossainy et al. Aug 2010 B1
7947207 Mcniven et al. May 2011 B2
8236039 Mackiewicz et al. Aug 2012 B2
8309023 Ramzipoor Nov 2012 B2
8333000 Huang et al. Dec 2012 B2
8925177 Huang et al. Jan 2015 B2
20010001128 Holman et al. May 2001 A1
20010044652 Moore Nov 2001 A1
20020002399 Huxel et al. Jan 2002 A1
20020004060 Heublein et al. Jan 2002 A1
20020004101 Ding et al. Jan 2002 A1
20020007207 Shin et al. Jan 2002 A1
20020035774 Austin Mar 2002 A1
20020062148 Hart May 2002 A1
20020065553 Weber May 2002 A1
20020068967 Drasler et al. Jun 2002 A1
20020111590 Davila et al. Aug 2002 A1
20020116050 Kocur Aug 2002 A1
20020138127 Stiger et al. Sep 2002 A1
20020138133 Lenz et al. Sep 2002 A1
20020161114 Gunatillake et al. Oct 2002 A1
20030033001 Igaki Feb 2003 A1
20030040772 Hyodoh et al. Feb 2003 A1
20030055482 Schwager et al. Mar 2003 A1
20030056360 Brown et al. Mar 2003 A1
20030093107 Parsonage et al. May 2003 A1
20030097172 Shalev et al. May 2003 A1
20030100865 Santini, Jr. et al. May 2003 A1
20030105518 Dutta Jun 2003 A1
20030105530 Pirhonen et al. Jun 2003 A1
20030171053 Sanders Sep 2003 A1
20030187495 Cully et al. Oct 2003 A1
20030208227 Thomas Nov 2003 A1
20030208259 Penhasi Nov 2003 A1
20030209835 Chun et al. Nov 2003 A1
20030212450 Schlick Nov 2003 A1
20030226833 Shapovalov et al. Dec 2003 A1
20030236565 DiMatteo et al. Dec 2003 A1
20040073155 Laufer et al. Apr 2004 A1
20040093077 White et al. May 2004 A1
20040098095 Burnside et al. May 2004 A1
20040111149 Stinson Jun 2004 A1
20040127970 Saunders et al. Jul 2004 A1
20040133263 Dusbabek et al. Jul 2004 A1
20040138731 Johnson Jul 2004 A1
20040143317 Stinson et al. Jul 2004 A1
20040167610 Fleming, III Aug 2004 A1
20040199246 Chu et al. Oct 2004 A1
20050096735 Hojeibane et al. May 2005 A1
20050118344 Pacetti Jun 2005 A1
20050143752 Schwager et al. Jun 2005 A1
20050154450 Larson et al. Jul 2005 A1
20050183259 Eidenschink et al. Aug 2005 A1
20050203606 VanCamp Sep 2005 A1
20050267408 Grandt et al. Dec 2005 A1
20050283962 Boudjemline Dec 2005 A1
20060004328 Joergensen et al. Jan 2006 A1
20060020285 Niermann Jan 2006 A1
20060030923 Gunderson Feb 2006 A1
20060041271 Bosma et al. Feb 2006 A1
20060047336 Gale et al. Mar 2006 A1
20060058863 LaFont et al. Mar 2006 A1
20060100694 Globerman May 2006 A1
20060229712 Wilson et al. Oct 2006 A1
20060287708 Ricci et al. Dec 2006 A1
20060288561 Roach et al. Dec 2006 A1
20070006441 Mcniven et al. Jan 2007 A1
20070204455 Knott et al. Sep 2007 A1
20070208370 Hauser et al. Sep 2007 A1
20070255388 Rudakov et al. Nov 2007 A1
20080097570 Thornton et al. Apr 2008 A1
20080208118 Goldman Aug 2008 A1
20090076448 Consigny et al. Mar 2009 A1
20090105747 Chanduszko et al. Apr 2009 A1
20090187210 Mackiewicz Jul 2009 A1
20090187211 Mackiewicz Jul 2009 A1
20090292347 Asmus et al. Nov 2009 A1
20100152765 Haley Jun 2010 A1
20110106234 Grandt May 2011 A1
20110257675 Mackiewicz Oct 2011 A1
20120035704 Grandt Feb 2012 A1
20120259402 Grandt Oct 2012 A1
20120283814 Huang et al. Nov 2012 A1
20130239396 Schwager et al. Sep 2013 A1
20130269168 Huang et al. Oct 2013 A1
20150074975 Huang et al. Mar 2015 A1
Foreign Referenced Citations (64)
Number Date Country
44 07 079 Sep 1994 DE
19509464 Jun 1996 DE
197 31 021 Jan 1999 DE
198 56 983 Dec 1999 DE
0 108 171 May 1984 EP
0 144 534 Jun 1985 EP
0 364 787 Apr 1990 EP
0 397 500 Nov 1990 EP
0 464 755 Jan 1992 EP
0 493 788 Jul 1992 EP
0 554 082 Aug 1993 EP
0 578 998 Jan 1994 EP
0 604 022 Jun 1994 EP
0 621 017 Oct 1994 EP
0 623 354 Nov 1994 EP
0 665 023 Aug 1995 EP
0 709 068 May 1996 EP
0716836 Jun 1996 EP
0 787 020 Aug 1997 EP
0935952 Aug 1999 EP
0 970 711 Jan 2000 EP
1 000 591 May 2000 EP
1 226 798 Jul 2002 EP
1 295 570 Mar 2003 EP
1637177 Mar 2006 EP
2 029 052 Mar 2009 EP
2196174 Jun 2010 EP
2322118 May 2011 EP
2 247 696 Mar 1992 GB
WO 8903232 Apr 1989 WO
WO 9001969 Mar 1990 WO
WO 9004982 May 1990 WO
WO 9006094 Jun 1990 WO
WO9117744 Nov 1991 WO
WO9117789 Nov 1991 WO
WO 9210218 Jun 1992 WO
WO 9306792 Apr 1993 WO
WO 9421196 Sep 1994 WO
WO 9529647 Nov 1995 WO
WO 9804415 Feb 1998 WO
WO 9903515 Jan 1999 WO
WO 9916382 Apr 1999 WO
WO 9916386 Apr 1999 WO
WO 9942147 Aug 1999 WO
WO 9955255 Nov 1999 WO
WO 0012147 Mar 2000 WO
WO 0064506 Nov 2000 WO
WO 0078249 Dec 2000 WO
WO 0101890 Jan 2001 WO
WO 0105462 Jan 2001 WO
WO 0121110 Mar 2001 WO
WO 02102283 Dec 2002 WO
WO 2004023985 Mar 2004 WO
WO 2004047681 Jun 2004 WO
WO 2005053937 Jun 2005 WO
WO 2006110861 Oct 2006 WO
WO 2007061927 May 2007 WO
WO 2008024491 Feb 2008 WO
WO 2008024621 Feb 2008 WO
WO 2008033621 Mar 2008 WO
WO 2009066330 May 2009 WO
WO 2009086205 Jul 2009 WO
WO 2010066446 Jun 2010 WO
WO 2011050979 May 2011 WO
Non-Patent Literature Citations (100)
Entry
U.S. Appl. No, 09/957,216, Jun. 10, 2003, Restriction Requirement.
U.S. Appl. No. 09/957,216, Sep. 26, 2003, Office Action.
U.S. Appl. No. 09/957,216, Jun. 14, 2004, Office Action.
U.S. Appl. No. 09/957,216, Feb. 16, 2005, Issue Notification.
U.S. Appl. No. 13/133,930, Mar. 27, 2013, Office Action.
U.S. Appl. No. 12/338,980, Jul. 18, 2012, Issue Notification.
U.S. Appl. No. 12/609,513, Aug. 24, 2012, Office Action.
U.S. Appl. No. 61/016,266, filed Dec. 21, 2007, Mackiewicz.
U.S. Appl. No. 61/138,455, filed Dec. 17, 2008, Haley.
U.S. Appl. No. 13/502,084, filed Oct. 29, 2010, Grandt.
U.S. Appl. No. 12/338,980, Aug. 2, 2010, Office Action.
U.S. Appl. No. 12/338,980, Oct. 27, 2010, Office Action.
U.S. Appl. No. 12/338,980, Mar. 1, 2011, Office Action.
U.S. Appl. No. 12/338,980, Apr. 3, 2012, Notice of Allowance.
U.S. Appl. No. 12/338,980, May 25, 2012, Notice of Allowance.
U.S. Appl. No. 12/338,981, Aug. 2, 2010, Office Action.
U.S. Appl. No. 12/338,981, Oct. 27, 2010, Office Action.
U.S. Appl. No. 12/338,981, Mar. 2, 2011, Office Action.
U.S. Appl. No. 12/537,097, Dec. 15, 2011, Office Action.
U.S. Appl. No. 12/537,097, Feb. 3, 2012, Office Action.
U.S. Appl. No. 12/609,513, Mar. 12, 2012, Office Action.
U.S. Appl. No. 13/151,893, Jan. 27, 2012, Office Action.
U.S. Appl. No. 13/151,893, Apr. 3, 2012, Office Action.
U.S. Appl. No. 12/609,513, Feb. 1, 2013, Office Action.
U.S. Appl. No. 12/537,097, Jun. 27, 2012, Office Action.
U.S. Appl. No. 09/957,216, Jan. 31, 2005, Issue Fee payment.
U.S. Appl. No. 09/957,216, Nov. 4, 2004, Notice of Allowance.
U.S. Appl. No. 09/957,216, Sep. 17, 2004, Response to Non-Final Office Action.
U.S. Appl. No. 09/957,216, Jun. 14, 2004, Non-Final Office Action.
U.S. Appl. No. 09/957,216, Mar. 8, 2004, Response to Non-Final Office Action.
U.S. Appl. No. 09/957,216, Sep. 26, 2003, Non-Final Office Action.
U.S. Appl. No. 09/957,216, Aug. 4, 2003, Response to Restriction Requirement.
U.S. Appl. No. 09/957,216, Jun. 10, 2003, Restriction Requirement.
U.S. Appl. No. 11/471,375, Nov. 14, 2012, Issue Fee payment.
U.S. Appl. No. 11/471,375, Aug. 17, 2012, Notice of Allowance.
U.S. Appl. No. 11/471,375, Jun. 12, 2012, Response to Final Office Action.
U.S. Appl. No. 11/471,375, Apr. 13, 2012, Final Office Action.
U.S. Appl. No. 11/471,375, Mar. 8, 2012, Response to Non-Final Office Action.
U.S. Appl. No. 11/471,375, Dec. 8, 2011, Non-Final Office Action.
U.S. Appl. No. 11/471,375, Jun. 16, 2011, Response to Non-Final Office Action.
U.S. Appl. No. 11/471,375, Mar. 16, 2011, Non-Final Office Action.
U.S. Appl. No. 11/471,375, Jan. 18, 2011, Amendment and Request for Continued Examination (RCE).
U.S. Appl. No. 11/471,375, Sep. 15, 2010, Final Office Action.
U.S. Appl. No. 11/471,375, Aug. 20, 2010, Response to Non-Final Office Action.
U.S. Appl. No. 11/471,375, Aug. 5, 2010, Non-Final Office Action.
U.S. Appl. No. 11/471,375, Mar. 29, 2010, Response to Non-Final Office Action.
U.S. Appl. No. 11/471,375, Feb. 2, 2010, Non-Final Office Action.
U.S. Appl. No. 11/471,375, Oct. 6, 2009, Response to Non-Final Office Action.
U.S. Appl. No. 11/471,375, Jul. 6, 2009, Non-Final Office Action.
U.S. Appl. No. 13/551,538, Nov. 13, 2013, Final Office Action.
U.S. Appl. No. 13/551,538, Sep. 10, 2013, Response to Non-Final Office Action.
U.S. Appl. No. 13/551,538, Jun. 10, 2013, Non-Final Office Action.
U.S. Appl. No. 13/779,636, Dec. 18, 2013, Non-Final Office Action.
Anonymous, “Bioabsorbable stent mounted on a catheter having optical coherence tomography capabilities”, Research Disclosure, pp. 1159-1162, (2004).
Ansari, “End-to-end tubal anastomosis using an absorbable stent”, Fertility and Sterility, 32(2):197-201 (1979).
Ansari, “Tubal Reanastomosis Using Absorbable Stent”, International Journal of Fertility, 23(4):242-243 (1978).
Bull, “Parylene Coating for Medical Applications”, Medical Product Manufacturing News, 18:1 (1993).
Casper, et al., “Fiber-Reinforced Absorbable Composite for Orthopedic Surgery”, Polymeric Materials Science and Engineering, 53:497-501 (1985).
Detweiler, et al., “Gastrointestinal Sutureless Anastomosis Using Fibrin Glue: Reinforcement of the Sliding Absorbable Intraluminal Nontoxic Stent and Development of a Stent Placement Device”, Journal of Investigative Surgery, 9(2):111-130 (1996).
Detweiler, et al., “Sliding, Absorbable, Reinforced Ring and an Axially Driven Stent Placement Device for Sutureless Fibrin Glue Gastrointestinal Anastomisis”, Journal of Investigative Surgery, 9(6):495-504 (1996).
Detweiler, et al., “Sutureless Anastomosis of the Small Intestine and the Colon in Pigs Using an Absorbable Intraluminal Stent and Fibrin Glue”, Journal of Investigative Surgery, 8(2):129-140 (1995).
Detweiler, et al., “Sutureless Cholecystojejunostomu in Pigs Using an Absorbable Intraluminal Stent and Fibrin Glue”, Journal of Investigative Surgery, 9(1):13-26 (1996).
Devanathan, et al., “Polymeric Conformal Coatings for Implantable Electronic Devices”, IEEE Transactions on Biomedical Engineering, BME-27(11):671-675 (1980).
Elbert, et al., “Conjugate Addition Reactions Combined with Free-Radical Cross-Linking for the Design of Materials for Tissue Engineering”, Biomacromolecules, 2(2):430-441 (2001).
Hahn, et al., “Bioeompatibility of Glow-Discharge-Polymerized Films and Vacuum-Deposited Parylene”, J Applied Polymer Sci, 38:55-64 (1984).
Hahn, et al., “Glow Discharge Polymers as Coatings for Implanted Devices”, ISA, pp. 109-111 (1981).
He, et al., “Assessment of Tissue Blood Flow Following Small Artery Welding with a Intraluminal Dissolvable Stent”, Microsurgery, 19(3):148-152 (1999).
Kelley, et al., “Totally Resorbable High-Strength Composite Material”, Advances in Biomedical Polymers, 35:75-85 (1987).
Kubies, et al., “Microdomain Structure in polylactide-block-poly(ethylene oxide) copolymer films”, Biomaterials, 21(5):529-536 (2000).
Kutryk, et al., “Coronary Stenting: Current Perspectives”, A companion to the Handbook of Coronary Stents, pp. 1-16 (1999).
Martin, et al., “Enhancing the biological activity of immobilized osteopontin using a type-1 collagen affinity coating”, J. Biomed. Mater Res, 70A:10-19 (2004).
Mauduit, et al., “Hydrolytic degradation of films prepared from blends of high and low molecular weight poly(DL-lactic acid)s”, J. Biomed. Mater. Res., 30(2):201-207 (1996).
Middleton, et al., “Synthetic biodegradable polymers as orthopedic devices”, Biomaterials, 21(23):2335-2346 (2000).
Muller, et al., “Advances in Coronary Angioplasty: Endovascular Stents”, Coron. Arter. Dis., 1(4):438-448 (1990).
Nichols, et al., “Electrical Insulation of Implantable Devices by Composite Polymer Coatings”, ISA Transactions, 26(4):15-18 (1987).
Peuster, et al., “A novel approach to temporary stenting: degradable cardiovascular stents produced from corrodible metal-results 6-18 months after implantation into New Zealand white rabbits”, Heart, 86(5):563-569 (2001).
Pietrzak, et al., “Bioabsorbable Fixation Devices: Status for the Craniomaxillofacial Surgeon”, J. Craniofaxial Surg., 8(2):92-96 (1997).
Pietrzak, et al., “Bioresorbable implants—practical considerations”, Bone, 19(1): 109S-119S (Supplement Jul. 1996).
Redman, “Clinical Experience with Vasovasostomy Utilizing Absorbable Intravasal Stent”, Urology, 20(1):59-61 (1982).
Rust, et al., “The Effect of Absorbable Stenting on Postoperative Stenosis of the Surgically Enlarged Maxillary Sinus Ostia in a Rabbit Animal Model”, Archives of Otolaryngology, 122(12):1395-1397 (1996).
Schatz, “A View of Vascular Stants”, Circulation, 79(2):445-457 (1989).
Schmidt, et al., “Long-Term Implants of Parylene-C Coated Microelectrodes”, Med & Biol Eng & Comp, 26(1):96-101 (1988).
Spagnuolo, et al., “Gas 1 is induced by VE-cadherin and vascular endothelial growth factor and inhibits endothelial cell apoptosis”, Blood, 103(8):3005-3012 (2004).
Tamai, et al., “Initial and 6-Month Results of Biodegradable Poly-I-Lactic Acid Coronary Stents in Humans”, Circulation, 102(4):399-404 (2000).
Tsuji, et al., “Biodegradable Polymeric Stents”, Current Interventional Cardiology Reports, 3(1):10-17 (2001).
Volkel, et al., “Targeting of immunoliposomes to endothelial cells using a single-chain Fv fragment directed against human endoglin(CD105)”, Biochimica et Biophysica Acta, 1663(1-2):158-166 (2004).
Von Recum, et al., “Degradation of polydispersed poly(L-lactic acid) to modulate lactic acid release”, Biomaterials, 16(6):441-445 (1995).
Yau, et al., “Modern Size-Exclusion Liquid Chromatography”, Wiley-Interscience Publication, Table of Contents IX-XV (1979).
European Search Report for EP Application No. 07809699.7, dated Jun. 12, 2004.
International Search Report for PCT/US2007/014331, dated Dec. 28, 2007.
U.S. Appl. No. 13/551,538, Apr. 15, 2014 Non-Final Office Action.
U.S. Appl. No. 13/779,636, Nov. 24, 2014 Amendment and Request for Continued.
U.S. Appl. No. 13/779,636, Dec. 29, 2014 Non-Final Office Action.
U.S. Appl. No. 13/779,636, Mar. 30, 2015 Response to Non-Final Office Action.
U.S. Appl. No. 13/779,636, Jun. 5, 2015 Final Office Action.
U.S. Appl. No. 13/551,538, Jun. 19, 2014 Applicant Initiated Interview Summary.
U.S. Appl. No. 13/551,538, Sep. 19, 2014 Notice of Allowance.
U.S. Appl. No. 13/551,538, Nov. 24, 2014 Issue Fee Payment.
U.S. Appl. No. 14/552,066, Jul. 29, 2015 Non-Final Office Action.
European Opposition dated Feb. 7, 2015 against European Patent EP 2066263.
Related Publications (1)
Number Date Country
20050143752 A1 Jun 2005 US
Divisions (1)
Number Date Country
Parent 09957216 Sep 2001 US
Child 11064692 US