Abstract: The invention provides a means of boosting the mechanical performance of shaped shaped medical devices comprising polymer hydrogels, such as stents, so that they may be more easily inserted into or removed from the body. In one aspect, the invention provides shaped medical devices having increased mechanical strength and comprising both ionic and covalent crosslinks. In another aspect, the invention provides a shaped medical device having a heterogeneous polymer composition and a variable dissolution or degradation rate along its length. The shaped medical devices according to the present invention retain their shape and stiffness during insertion into the body and can swell and soften inside the body to enhance patient comfort.
Type:
Grant
Filed:
February 25, 2000
Date of Patent:
April 9, 2002
Assignee:
SciMed Life Systems, Inc.
Inventors:
Sheng Ping Zhong, Arthur R. Madenjian, Douglas E. Godshall, John M. Ronan, Samuel A. Thompson
Abstract: Vascular grafts, and methods for making the same, are provided. The vascular grafts comprise a graft tissue derived from a biological source that is enclosed within an external synthetic sleeve. The synthetic sleeve has an extended length that is greater than the length of the graft tissue. However, the sleeve is longitudinally compressed such that it has a resting length substantially similar to the length of the graft tissue.
Type:
Grant
Filed:
October 4, 1999
Date of Patent:
March 19, 2002
Assignee:
Sulzer Carbomedics Inc.
Inventors:
Brian K. Mcllroy, Tim Ashton, Roshan Maini, Richard E. Phillips
Abstract: A vascular access graft that is radially supported and self-sealing upon puncture with, for example, a dialysis needle. The graft has at least one access segment that is formed by an inner layer, an intermediate layer, and outer layer. The intermediate layer has, in longitudinal cross-section, regions of different densities. Radial support members within the intermediate layer prevent collapse of vascular access graft and may be formed of a material that has a lower melting temperature than the other components of the graft. A porous or low-density material is provided between the radial support members to permit blood seepage therein, and the graft is formed by heating to cause the radial support members to melt slightly into the interstitial spaces of the low-density material. The radial support members may be individual turns of a helical coil of FEP, and the low-density material may be compressed PTFE “cotton”. The inner and outer layers may also be formed of PTFE.
Abstract: An implantable, bioresorbable vessel wall support, in particular a coronary stent, comprises a combination of metal materials which dissolves in the human body without any harmful effects on the person that wears the implant. The combination of metal materials can be an alloy or a local galvanic element.
Type:
Grant
Filed:
June 25, 1999
Date of Patent:
September 11, 2001
Assignee:
Biotronik Mess- und Therapiegeraete GmbH & Co.
Ingenieurbuero Berlin
Abstract: Partially encapsulated stents are made using strips and bands of covering material. In one embodiment ringed stents are placed over an inner ePTFE tube (e.g., supported on a mandrel) and are covered by a series of longitudinal strips. A series of spaced apart ePTFE circumferential bands can then be placed over the top of the longitudinal strips and ringed stents; alternatively bands alone or strips alone may be employed. All of the components of the structure are then laminated to the inner ePTFE tube to capture the stent. By selecting the size and position of the ePTFE bands, it is possible to leave critical parts of the stent unencapsulated to facilitate flexibility and expansion. The longitudinal strips can be woven about the stent and later laminated into position to provide an anti-compression function as well as overall structural stability. Although a single stent can be used, these approaches lend themselves to use of a plurality of individual ring stents spaced apart along the inner ePTFE tube.
Abstract: The invention describes the possibility of the biofunctionalization of biomaterials, in particular implants, by their made-to-measure coating with synthesized cell- or tissue-selective RGD peptides which in vitro stimulate the adhesion of mainly those cell species which in each case are intended to accomplish the tissue integration of the appropriate biomaterial.
Type:
Grant
Filed:
November 22, 1999
Date of Patent:
August 28, 2001
Assignee:
Merck Patent Gesellschaft mit beschraenkter Haftung
Inventors:
Jorg Meyer, Alfred Jonczyk, Berthold Nies, Horst Kessler, Dirk Finsinger, Martin Kantlehner
Abstract: An expanded polytetrafluoroethylene flanged vascular graft (10) suitable for end-to-side anastomosis grafting having an integral terminal polytetrafluoroethylene flanged skirt or cuff section (12) which facilitates an end-to-side anastomosis directly between an artery and the expanded polytetrafluoroethylene flanged bypass graft (10) without need for an intervening venous collar or venous patch.
Type:
Grant
Filed:
December 8, 1998
Date of Patent:
August 14, 2001
Assignee:
Impra, Inc.
Inventors:
Hans Scholz, Ulf Kruger, Utz Settmacher
Abstract: A vascular implant formed of a compressible foam material has a compressed configuration from which it is expansible into a configuration substantially conforming to the shape and size of a vascular site to be embolized. Preferably, the implant is formed of a hydrophilic, macroporous foam material, having an initial configuration of a scaled-down model of the vascular site, from which it is compressible into the compressed configuration. The implant is made by scanning the vascular site to create a digitized scan data set; using the scan data set to create a three-dimensional digitized virtual model of the vascular site; using the virtual model to create a scaled-down physical mold of the vascular site; and using the mold to create a vascular implant in the form of a scaled-down model of the vascular site. To embolize a vascular site, the implant is compressed and passed through a microcatheter, the distal end of which has been passed into a vascular site.
Type:
Application
Filed:
December 5, 2000
Publication date:
May 24, 2001
Inventors:
George R. Greene, Robert F. Rosenbluth, Brian J. Cox
Abstract: The present invention provides controlled expansion endoluminal prostheses and methods for their deployment and expansion. The present stent-grafts generally comprise a radially expansible tubular frame and a plastically expansible liner on the frame. Either the frame or the liner includes a reinforcing element which limits expansion of the stent-graft at a predetermined expanded size. In some embodiments, the reinforcing element restrains the frame, for example, by limiting the circumferential diagonals of perforations on a perforate frame structure. Generally, however, the reinforcing element is included in the liner as circumferentially oriented yarn. A particularly advantageous liner includes composite circumferential yarns having inexpansible fibers wrapped around an expansible fiber, such as a partially oriented yarn, PTFE, or the like.
Type:
Grant
Filed:
February 25, 1998
Date of Patent:
January 23, 2001
Assignee:
Medtronic, Inc.
Inventors:
Jay A. Lenker, Brian J. Cox, Michael A. Evans, Steven Weinberg
Abstract: The present invention provides methods for modifying surfaces made from metal alloy and/or UHMWPE, preferably surfaces which are frictionally engaged, e.g., in an orthopaedic implant. The methods of the present invention reduce the coefficient of friction of the metal alloy component, reduce the shearing of fibrils from the UHMWPE component, and reduce sub-surface fatigue in the UHMWPE component. The method involves solvent immersion of the UHMWPE component to remove short chains of polyethylene at or near the surface of the component, and to swell and toughen the subsurface of the component. The method also involves firmly coating the surface of the metal alloy component with an adherent layer of diamond-like carbon (“DLC”) by creating a metal-silicide interface at the surface of the metal alloy to permit firmer adhesion of DLC.
Type:
Grant
Filed:
April 30, 1997
Date of Patent:
January 9, 2001
Assignee:
Southwest Research Institute
Inventors:
Geoffrey Dearnaley, James Lankford, Jr.