Abstract: A method for making a blood-contacting medical device with improved biocompatibility by applying to the blood-contacting surface an aqueous solution of heparin and then overcoating the heparin with a porous polymer. The inclusion of a porous polymer in intimate contact with a heparin on the device controls the administration of heparin following implantation or other blood contact. The adhesion of the coating and the rate at which the heparin is delivered can be controlled by the selection of an appropriate bioabsorbable or biostable polymer.

Abstract: A medical device having a surface graft matrix comprising carboxyl-functional groups located on the device, the surface graft matrix comprising an outer portion; and one or more biomolecules covalently coupled to the surface graft matrix, wherein a majority of the biomolecules are located in the outer portion of the surface graft matrix. The surface graft matrix can also be loaded with a pharmaceutical agent.

Abstract: A radially expandable stent for implantation within a body lumen having a generally cylindrical body with open proximal and distal ends, the cylindrical body comprising a plurality of metal elements joined to allow flexing of the cylindrical body along the longitudinal axis of the body whereby the stent can conform to a curved body lumen and a polymeric film extending between the metal elements of the stent. The stent provides a biocompatible polymeric surface to contact and support a body lumen and also a flexible structure to allow the stent to conform closely to bends in a body lumen. The stent is especially useful for repairing an injury to blood vessels caused during angioplasty procedures.

Abstract: An intraluminal stent comprising fibrin is capable of reducing the incidence of restenosis at the site of vascular injury such as that produced by an angioplasty procedure.

Abstract: A medical article having a metal or glass surface with the surface having an adherent coating of improved biocompatibility. The coating is made by first applying to the surface an silane compound having a pendant vinyl functionality such that the silane adheres to the surface and then, in a separate step, forming a graft polymer on the surface with applied vinylsilane such that the pendant vinyl functionality of the vinylsilane is incorporated into the graft polymer by covalent bonding with the polymer. Biomolecules may then be covalently attached to the base layer.

Abstract: A stent for providing support to a body lumen comprises a wire wound in a continuous winding into a generally cylindrical shape with the cylindrical shape terminating at one end in a closed loop of the wire and a line of elongated flexible material extending through the closed loop and looped back on itself at the closed loop such that the line is secured to the winding at the closed loop and is freely slideable through the closed loop. If necessary, this stent can be readily removed from the body lumen after implantation or left in the body lumen as a permanent implant.

Abstract: Systems and methods for delivering a radially expandable stent for implantation within a body vessel that provide for the controlled radial expansion of the stent simultaneous with controlled axial movement of the ends of the stent, whereby controlled delivery of the stent can be accomplished. The device may include a screw rotated to simultaneously radially expand and axially compress a stent that has been previously wound onto a delivery device.

Abstract: A device for delivery of a therapeutic substance into a body lumen including a polymer in intimate contact with a drug on a stent allows the drug to be retained on the stent during expansion of the stent and also controls the administration of drug following implantation. The adhesion of the coating and the rate at which the drug is delivered can be controlled by the selection of an appropriate bioabsorbable or biostable polymer and the ratio of drug to polymer.

Abstract: A method of treating a patient with a medical device having immobilized heparin on a blood-contacting surface in which the covalently attached heparinized surface is provided with an adsorbed protein which may be activated by the immobilized heparin to block the coagulation of fibrinogen. Antithrombin III is the preferred adsorbed protein. The adsorbed protein is maintained on the immobilized heparin surface until the medical device is placed into contact with the patient's blood. When in contact with the patient's blood, the adsorbed protein will prevent initial thrombin formation at the biomaterial-blood interface. The preadsorption of ATIII is accomplished under conditions advantageous to maximum heparin/ATIII binding. When the preadsorbed surface comes in contact with whole blood, the maximum advantage of prophlactic properties of ATIII/heparin are obtained.

Abstract: A feedthrough configuration for a hermetically sealed implantable medical device includes a metal case having an aperture and a feedthrough in the aperture which includes a ferrule sealed in the aperture, a pin extending through the ferrule and the aperture, an insulating material supporting the pin within the ferrule and an electrically conductive block spaced from the ferrule and in electrical connection with the pin. A device for electrical or electromagnetic protection can be connected to a peripheral upstanding portion of the ferrule and a peripheral skirt portion of the block. This arrangement of feedthrough elements can be particularly useful if the protective device is a chip capacitor which typically has a flat-sided configuration that can bridge the space between the ferrule and the block and be connected at one end to the block and at the other end to the ferrule.

Abstract: To minimize the incidence and consequences of device related infection that occur after prosthetics implants of neuro-muscular stimulating devices, an infection resistant intramuscular lead has been developed. Infection incidence has been decreased by using biomaterials able to release antibacterial drugs (gentamicin) at a controlled rate for the first 3-6 weeks after implant.

Abstract: A prosthesis for insertion into a lumen to limit restenosis of the lumen. The prosthesis carries restenosis-limiting drugs which elute after the device is positioned in the lumen.

Abstract: A method of making a high reliability electrical connection in an implantable medical device. The electrical conductors may include metals such as niobium, molybdenum, tantalum, platinum, titanium, nickel and alloys thereof. The electrical conductors are resistance welded by establishing contact between the conductor pair, providing a protective atmosphere around the contacting pair, and applying electrical energy to the contacting pair to cause fusion while maintaining the protective atmosphere.

Abstract: An improved spacer material for improving the biocompatibility of a biomaterial and a method for making it in which a polyalkylimine is covalently attached to an aminated substrate and combined with a crosslinking agent which is at least difunctional in aldehyde groups. The polyalkylimine can be for example, polyethyleneimine and the crosslinking agent can be, for example, glutaraldehyde. Preferably, the crosslinking agent is applied in dilute solution and at a pH suitable to accomplish light crosslinking of the polyalkylimine and also provide aldehyde linkages at the interface between the biomolecule and the spacer.

Abstract: An intraluminal stent comprising fibrin and an elutable drug is capable of providing a treatment of restenosis.

Abstract: An improved method of making a medical device having immobilized heparin on a blood-contacting surface in which heparin is admixed with sufficient periodate to react with not more than two sugar units per heparin molecule in a buffer solution having a pH in the range of about 4.5-8. This mixture is reacted for at least 3 hours while protected from light and is then applied to the immobilized amine groups. This is an improvement over the prior art methods which included using an excess of periodate and then stopping the reaction at a desired point by the addition of glycerol since the conversion of only a few of the natural functional groups to aldehydes better preserves the antithrombotic bioeffectiveness of the heparin molecules bound to the surface. The invention also avoids the prior art steps of drying and reconstituting the heparin by providing a reacted mixture of heparin and periodate that can be stored as a stable liquid and applied directly to the aminated surface several days later.

Abstract: A method for making an intravascular stent by applying to the body of a stent a solution which includes a solvent, a polymer dissolved in the solvent and a therapeutic substance dispersed in the solvent and then evaporating the solvent. The inclusion of a polymer in intimate contact with a drug on the stent allows the drug to be retained on the stent during expansion of the stent and also controls the administration of drug following implantation. The adhesion of the coating and the rate at which the drug is delivered can be controlled by the selection of an appropriate bioabsorbable or biostable polymer and the ratio of drug to polymer in the solution. By this method, drugs such as dexamethasone can be applied to a stent, retained on a stent during expansion of the stent and elute at a controlled rate.

Abstract: An improved coating and spacer material for a medical device having a blood or tissue-contacting surface comprising a polyalkyleneimine layer which is crosslinked with a crosslinking agent which is at least difunctional in polymerizable vinyl groups which have adjacent strong electron-withdrawing groups and a biomolecule covalently bonded to the crosslinked polyalkyleneimine layer. For example, polyethyleneimine crosslinked with divinyl sulfone could be used. The resulting crosslinked spacer layer has improved uniformity and stability without materially limiting the covalent attachment of a biomolecule such as heparin.

Abstract: A vascular graft having a pleated circumference accommodates blood pressure changes with minimal change in internal surface area. A highly compliant graft may be made from a wide variety of polymers including non-elastomeric materials.

Abstract: A medical device for use in the interior of a body lumen including a catheter and a radially expandable stent mounted on the catheter. The radially expandable stent is in the form of a hollow cylinder defined by a sequence of spaced apart wire elements with each of the wire elements extending 360 degrees around the cylinder and the wire elements having extendible, sinusoidal zig-zags lying flat with respect to the cylinder. The zig-zags are shaped in a generally longitudinal direction along the cylinder at one point and then reverse their direction so that the zig-zags may open as the wire element is expanded. The adjacent wire elements are flexibly connected together in an end-to-end fashion by helical winding.