Abstract: A catheter introducing system includes an introducer catheter comprising a flexible sheath having a hemostasis valve and an obturator having a steering mechanism operated by a proximal actuator handle. The catheter introducer system will usually be introduced with the obturator inside of the flexible sheath so that the obturator can effect steering by laterally deflecting the distal end of the combined sheath and obturator. Such catheter introducing systems are particularly useful for large diameter sheaths which are not readily introduced over guide wires. A first exemplary hemostasis valve comprises a compressed foam insert having an axial lumen therein. A second exemplary hemostasis valve comprises an elastomeric insert which receives and seals over the catheter.

Abstract: An endolumenal prosthesis delivery assembly includes an endolumenal prosthesis which is delivered to a desired location within a body lumen by used of first and second delivery members. The first delivery member has a prosthesis coupler that is adapted to removeably engage the prosthesis during delivery to the desired location and to release the prosthesis and implant it at the desired location. The second delivery member has an anchor on its distal end portion which is adapted to secure the second delivery member within the body lumen distally of the desired location for stenting. Once the second delivery member is anchored, the first delivery member is slideably advanced over the second delivery member until the prosthesis is positioned at the desired location. The anchor along the second delivery member according to this assembly is either an expandable member, such as a balloon, or is otherwise adapted to engage the body lumen wall, such as by use of suction or other mechanical means.

Abstract: A encapsulated stent device for implantation within the vascular system includes a balloon of a balloon catheter formed around and adhered to a wire-like stent so that the outer surface of the device is more regular for delivery through the vascular system without an exterior sheath. The encapsulation securely anchors the stent to the balloon and maintains a low profile for negotiation of tortuous and narrowed vessels. Encapsulation requires placement of the stent over the balloon, placement of a sheath over the stent on the balloon, heating and preferably pressurization of the balloon to cause it to expand around the stent within the sheath, and cooling while preferably maintaining pressure to cause the balloon to adhere to the stent and to set the shape of the expanded balloon. Retainers may be placed at the distal and/or proximal ends of the stent during the encapsulation process, or the balloon material may expand to form retainers.

Abstract: An endoprosthesis is provided having an expandable, generally cylindrical body portion defining an inside surface and an outside surface. The inside surface is preferably regular and smooth to yield a low coefficient of friction, while the outside surface is modified to yield a relatively high coefficient of friction with a vessel surface, includes a macroscopic surface modification to engage the vessel surface, or includes an adhesive coating that bonds the stent to the vessel surface.

Abstract: A coating is provided comprising a polyurethane network formed from the reaction on a substrate to be coated, of a mixture comprising a polyisocyanate; a hydroxyl donor and/or amine donor; a polymer selected from the group consisting of polyethylene oxide, polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, and polyacrylic acid; and an isocyanatosilane adduct having terminal isocyanate groups and at least one hydrolyzable alkoxy group bonded to silicon in a solvent. A method for preparing the coating is also provided.

Abstract: A method of manufacturing an X-ray device is described including the step of coupling a housing that includes diamond to an anode structure that includes diamond. Further, a target metal may be formed on a tip of the anode structure. An X-ray device is also described including a housing made of diamond, a cathode within the housing, and an anode structure that includes diamond. The anode structure may include conductive diamond, while the housing structure may include high resistivity diamond.

Abstract: Balloons and balloon catheters with a superior overall combination of distensibility, elastic stress response and strength. The improved properties of the balloons result from the method or process used to form the balloons, as well as the polymeric materials used in said balloon forming process. Additionally, the enhanced combination of properties of the balloons will not be adversely affected by the novel sterilization process contemplated by this invention.

Abstract: A thrombolytic filtration and drug delivery catheter is disclosed comprising a shaft which longitudinal ribs. The ribs are compressed while being advanced to the site of interest and are released at the site, flaring to a diameter greater than the diameter of the shaft. The ribs can be compressed by a sleeve or thread, for example. Drugs or other agents can be delivered through lumens in the shaft and ribs, out through ports in the ribs. Preferably, the ports are positioned to deliver the drugs or other agents between the ribs and within the region defined by the ribs.

Abstract: The present invention provides a device and method for delivering a therapeutic substance to a treatment site within a patient such as a vessel that has undergone angioplasty. The device provides flexible conduits placed together in the vessel along with a shaft that is attached to their distal ends. After being navigated to the treatment site, the shaft may be moved relative to the conduits causing them to buckle and bow radially outward into contact with the tissue to be treated. The therapeutic substance is then pressurized to be delivered through perfusion ports along the distal portion of the conduits. Because the conduits can be expanded into contact with the treatment site without the assistance of an inflatable member, blood flow through the region during delivery of the therapeutic substance is not interrupted in any significant way. Alternatively, the present invention may be used in conjunction with a balloon angioplasty catheter to deliver therapeutic substances after the dilatation procedure.

Abstract: A method described includes positioning an x-ray emitter at a treatment area, where the x-ray emitter is connected to a cable, setting a voltage source at a source voltage, and measuring a current through the x-ray emitter. The method may include comparing a current flowing through the emitter with a high limit and a low limit. The method further includes increasing the source voltage if the current is lower than the low limit. The method further includes decreasing the source voltage if the current is higher than the high limit. The method includes determining the high limit and the low limit based on the source voltage and the desired radiation.

Abstract: A cathode structure comprising a getter material provided with a diamond film. The getter material may include zirconium, vanadium and iron. Cathode structures may have a substantially rounded configuration including a substantially straight portion. Other cathode structures may have a substantially flat portion, with the diamond film covering essentially the entire flat surface. Methods of manufacturing cathode structures may include conditioning the cathode structure by applying a voltage.

Abstract: An apparatus is described for irradiating a stenosed region of an artery by use of a sliding or floating radiation source inserted into or onto a catheter or onto a guide wire within a catheter, delivered to the treatment site by a mechanical or hydraulic fluid and housed at the site for the irradiation procedure.

Abstract: A catheter for emitting radiation is disclosed, comprising a catheter shaft and an x-ray unit attached to the distal end of the catheter shaft. The x-ray unit comprises an anode and a cathode coupled to an insulator to define a vacuum chamber. The cathode is preferably a field emission cathode of graphite or graphite coated with titanium carbide, for example. The anode is preferably tungsten and the insulator is preferably pyrolytic boron nitride. The x-ray unit is preferably coupled to a voltage source through a coaxial cable. The anode is preferably a heavy metal such as tungsten. The cathode may also be a ferroelectric material. The x-ray unit can have a diameter less than about 4 mm and a length less than about 15 mm. Methods of use of the catheter are also disclosed. The catheter of the present invention can be used to irradiate the site of an angioplasty procedure to prevent restenosis. It can also be used to treat other conditions in any vessel, lumen or cavity of the body.

Abstract: A system and method for effecting rapid exchange of catheters over a guidewire. A gripping mechanism is provided on one of a guide catheter and a guidewire to grip the other of the guide catheter and guidewire proximate to the distal end of the guide catheter. When engaged, the gripping mechanism inhibits movement between the guidewire and the guide catheter when a first catheter is exchanged with a second catheter over the guidewire.

Abstract: Coatings are provided in which biopolymers may be covalently linked to a substrate. Such biopolymers include those that impart thromboresistance and/or biocompatibility to the substrate, which may be a medical device. Coatings disclosed herein include those that permit coating of a medical device in a single layer, including coatings that permit applying the single layer without a primer. Suitable biopolymers include heparin complexes, and linkage may be provided by a silane having isocyanate functionality.

Abstract: A method and apparatus are provided for releasably storing the additional exchange length of a medical guidewire within a housing, in a compacted configuration until it is needed by the physician to perform a catheter exchange. This guidewire has a distal portion which is similar to a traditional guidewire in length and construction and is used throughout the catheterization procedure much like a conventional guidewire. A proximal portion of the guidewire provides added length to effect a catheter exchange in the manner of a conventional exchange wire but may be tightly compacted and stored out of the way within a storage receptacle until the moment that the added length is needed for an exchange. The storage receptacle enables the physician to utilize the distal portion of the guidewire wire much like a conventional guidewire, then release the proximal portion quickly to effect a catheter exchange.

Abstract: A coating is provided for a substrate comprising a polyisocyanate; an amine donor and/or hydroxyl donor; an isocyanatosilane adduct having terminal isocyanate groups and at least one hydrolyzable alkoxy group bonded to silicon; and optionally a polymer selected from the group consisting of polyethylene oxide, polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, and polyacrylic acid. The coating can accommodate a drug so that when the coating is applied to a medical device, the medical device becomes drug-releasing when in contact with aqueous body fluid. A coated article as well as a method for preparing the coating is also provided.

Abstract: A guidewire system for use in catheter exchanges avoids the need for a separate exchange wire by connecting an extension wire to the proximal end of the guidewire thereby increasing the effective length of the guidewire to permit a catheter exchange. The proximal end of the guidewire is attached to the distal end of the exchange wire by a disconnectable, reattachable connection which avoids deformation of the connected joint. The connection includes a male element in the form of a reduced diameter rod extending axially from the proximal end of the guidewire and a female element attached to the distal end of the extension wire. The female element includes a helical coil receptive to the rod and dimensioned to receive the rod in an interference fit requiring the spring to expand. Separation is effected by imparting a combined twisting and axial separation motion to the guidewire and extension wire.

Abstract: A drug storing and metering stent for placement within a vessel comprising an outer member having a lumen, an inner member positioned within the lumen of the outer member. A space separates the inner member from the outer member and within which space a therapeutic drug is disposed. The stent includes at least one protrusion provided on at least one of the inner and outer members and extending across the space so as to cause a friction fit between the inner and outer members. The stent also includes a pattern of perforation across both the inner and outer members to permit the stent to expand radially. The invention also relates to a method of making such a stent, and a method of releasing a therapeutic drug within a vessel.

Abstract: A guidewire for use in guiding a catheter has a tip construction that includes a core wire within a helical coil. The core wire has a distal tip segment that is tapered and is further impressed with a pair of opposed flattened surfaces extending along the taper, the surfaces lying at an angle to each other and defining a progressively flattened tip having increased width in a distal direction to define a duck-bill configuration. The tip construction provides improved column strength at the tip to resist guidewire prolapse while providing excellent torsional and flexibility characteristics.