Abstract: Disclosed are bio-active coating compositions for polymeric substrates. In particular, a bio-active coating is described which is the reaction product formed by providing a polymer backbone with at least one free isocyanate group, wherein the isocyanate group is pendant from the polymer backbone. There is further provided a hydrophilic, amine-terminated spacer which has at least one amine group at its first and second ends. One of the amine groups of the spacer is reacted with one or more of the isocyanate groups on the polymer backbone in the presence of an optional catalyst agent. A bio-active agent is then covalently bonded onto an unreacted end of the spacer in the presence of a catalyst. Also disclosed are coating compositions for a substrate and methods of preparing same.

Abstract: A valve sizer having a movable element mounted to the distal end of a shaft. A valve sizing portion includes the movable element so that the valve sizing portion may be adjusted to correspond to a number of different available replacement valve sizes. An indicator mounted to the proximal end of the shaft indicates the valve size corresponding to the outer dimension of the valve sizing portion.

Abstract: A holder is provided for carrying a prosthetic ring which allows for manipulation and handling of the ring during implantation in a heart. The holder includes a holder body configured to fit the ring. A boss extends around the holder body. A backing lip extends from a proximal end of the boss and has a diameter that is greater than a diameter of the boss. A shoulder tab extends only partially around the distal end of the boss and extends beyond a diameter of the boss. The prosthetic ring mates with the boss and the backing lip to thereby hold the prosthetic ring.

Abstract: A heart valve prosthesis including a heart valve formed of a flexible material. An elongated stent member is provided in the valve and includes terminal ends. A plurality of flexible post members are formed in the stent member. Each post member includes a pair of opposite sides. A crimp collar interconnects the terminal ends of the stent member. The crimp collar is positioned between adjacent post members. A first radius is formed in the stent member between the crimp collar and an adjacent side of each adjacent post member. A plurality of second radii are formed in the stent member between an opposite side of a first one of the adjacent post members and an opposite side of a second one of the adjacent post members. The second radii are greater than each first radius.

Abstract: A valve includes an elastic valve body and a stent. A first portion of the stent is embedded in the elastic valve body and a second portion of the stent is outside the valve body. A method of manufacturing such a valve is also claimed.

Abstract: A cardiovascular valve system including a permanent base unit that is affixed to the patient using conventional sutures or staples, and a collapsible valve having a collapsible frame that mates with the permanent base unit, and supports valve leaflets. An installed collapsible frame may be re-collapsed and disengaged from the permanent housing. A new collapsible valve is then installed, to resume the function of the prosthesis.

Abstract: Herein are disclosed devices, particularly medical devices, more particularly implantable medical devices, comprising a first layer of a metal and a short chain silicone terminating with silicon hydride, and a second layer of a silicone polymer. The short chain silicone is bound to the metal, and the silicone polymer is covalently bound via the vinyl group to the silicon hydride group of the short chain silicone. Also disclosed herein is a method for making such devices, involving providing the metal, depositing the short chain silicone, molding the silicone polymer as a silicone prepolymer, and polymerizing the silicone prepolymer to yield silicone polymer covalently bonded to the short chain silicone.

Abstract: An implant device is provided which is responsive to an external interrogation circuit. The implant device includes a structure implantable within a living animal and operatively configured to carry out or assist in carrying out a function within the living animal. The device further includes an electrically passive sensing circuit integral with the structure for sensing a parameter associated with the function. In particular, the sensing circuit includes an inductive element wherein the sensing circuit has a frequency dependent variable impedance loading effect on the interrogation circuit in response to an interrogation signal provided by the exciter/interrogator element, the impedance loading effect varying in relation to the sensed parameter.

Abstract: A valve prosthesis (9) for implantation in the body by use of catheter (11) comprises a stent made from an expandable cylinder-shaped thread structure (2,3) comprising several spaced apices (4). The elastically collapsible valve (6) is mounted on the stent as the commissural points (5) of the valve (6) is secured to the projecting apices (4). The valve prosthesis (9) can be compressed around the balloon means (13) of the balloon catheter (11) and be inserted in a channel, for instance in the aorta (10). When the valve prosthesis is placed correctly the balloon means (13) is inflated thereby expanding the stent and wedging it against the wall of the aorta. The balloon means is provided with beads (14) to ensure a steady fastening of the valve prosthesis on the balloon means during insertion and expansion. The valve prosthesis (9) and the balloon catheter (11) make it possible to insert a cardiac valve prosthesis without a surgical operation comprising opening the thoracic cavity.

Abstract: A suture ring for a rotatable artificial heart valve apparatus has a ring member covered by a fabric material. A portion of the fabric material covers a portion of the inner surface of the ring member. At least one protuberance is formed on the inner surface of the ring member so as to mitigate the frictional resistance to rotation which results from compression of the fabric between the suture ring and the heart valve. Thus, desirable rotation of the heart valve relative to the suture ring is assured over a range of thicknesses of the fabric material.

Abstract: An apparatus controls a direction of formation of a hole through a myocardium for subsequent placement into the hole of a myocardial portion of a transmyocardial implant. The implant also includes a coronary portion having a coronary axis set at an implant angle to a myocardial axis of the myocardial portion. The apparatus includes a base member having base surface for placement against an epicardial surface of a heart adjacent a coronary vessel having a vessel axis. The base member has a determinable base axis for placement of the base surface on the epicardial surface with the base axis parallel with the vessel axis. A support member supports a myocardial penetrator for movement along a support axis in a line of travel parallel to the support axis and substantially restricting the myocardial penetrator from movement transverse to the support axis. The support member is secure to the base member with the support axis and base axis defining a support angle.

Abstract: Bioprosthetic devices made of collagen-based material having collagen amine groups and collagen carboxyl groups are provided as well as methods for their formation. The methods comprise combining an epoxy functionalized crosslinking agent with the collagen-based material in an aqueous medium at an acidic pH to react a portion of the collagen carboxyl groups with the epoxy functionalized crosslinking agent to form crosslinked collagen-based material comprising residual collagen carboxyl groups.

Abstract: A method is disclosed for using tubular material to replace a semilunar heart valve (i.e., an aortic or pulmonary valve). To create such a replacement valve, the native valve cusps are removed from inside an aorta or pulmonary artery, and the inlet end of a tubular segment is sutured to the valve annulus. The outlet (distal) end of the tube is either "tacked" at three points distally, or sutured longitudinally along three lines; either method will allow the flaps of tissue between the suture lines to function as movable cusps. This approach generates flow patterns that reduce turbulence and closely duplicate the flow patterns of native semilunar valves. An article of manufacture is also disclosed, including a sterile biocompatible synthetic material which has been manufactured in tubular form, by methods such as extrusion or coating a cylindrical molding device, to avoid a need for a suture line or other seam to convert a flat sheet of material into a tubular shape.

Abstract: A prosthetic cardiac valve assembly for sutureless implantation in a patient. The assembly includes a generally disk-shaped valve annulus element and one or more generally disk-shaped retainer elements. The elements are adapted for mutual engagement and for engagement with a host tissue region so as to fix a portion of the host tissue between them in a sutureless bond. Ultrasonic or thermal energy is applied to one or more of the elements to bond them together. Either the valve annulus element or the retainer element includes a plurality of projections, and the corresponding element includes a corresponding plurality of apertures for receiving the projections, thus providing for mutual physical engagement. The valve annulus element can include a plurality of valve leaflets which open and close in response to fluid pressure differentials across them. Various insertion devices for the assembly are designed to facilitate insertion of the elements in the heart through a relatively small incision.

Abstract: A valve sizer having a movable element mounted to the distal end of a shaft. A valve sizing portion includes the movable element so that the valve sizing portion may be adjusted to correspond to a number of different available replacement valve sizes. An indicator mounted to the proximal end of the shaft indicates the valve size corresponding to the outer dimension of the valve sizing portion.

Abstract: A flexible self-expandable stent comprises a plurality of radially cylindrical elastic units spaced at fixed intervals, a cylindrical cover fixing member which sheaths the cylindrical elastic units, and a reverse flow preventing valve. The reverse flow preventing valve is attached to the inner wall of the stent, for preventing food-stuffs or fluids from flowing from a downstream side to an upstream side. The flexible self-expandable stent exhibits improved flexibility so that when the stent is disposed in a curved lumina, it can flexibly correspond to the curvature of the lumina and prevent the reverse flow of foodstuffs or fluids by use of the reverse flow preventing valve.

Abstract: A thin-wall PTFE (polytetrafluoroethylene) tube in the form of a tube of porous expanded PTFE film wherein the porous PTFE film has a microstructure containing a multiplicity of fibrils oriented substantially parallel to each other. The tube has a wall thickness of less than about 0.25 mm and is made from at least one first layer and at least one second layer of porous PTFE film, wherein the fibrils of the first and second layers are oriented substantially perpendicular to each other. Preferably the fibrils of the at least one first layer are oriented substantially parallel to the longitudinal axis of the tube and the fibrils of the at least one second layer of porous PTFE film are oriented substantially circumferential to the tube. The first and second layers may be inner and outer layers respectively, or alternatively their relationship may be reversed.

Abstract: A stent for receiving and supporting a tissue heart valve for ultimate implantation into a human, the heart valve including tissue leaflets joined at circumferentially spaced commissures, wherein the stent includes at least one commissure support post and at least one sinus support structure each sinus support structure being disposed between but not functionally connected to an adjacent commissure support post.

Abstract: The invention relates to a mechanical heart valve for artificial blood pumps and conduits. An occluder is located in a flow channel with an S-shaped center line and with a cross sectional area which decreases in the flow direction. The occluder is made in the form of a rotational body which can be turned around a pivot or virtual axis, which is located outside the center of gravity of the rotational body.

Abstract: Heart valve leaflet selection methods and apparatuses which subject individual leaflets to loads and measure the resulting deflection to more reliably group leaflets of similar physical characteristics for later assembly in prosthetic heart valves. The deflection testing may be accomplished using a variety of test set ups which are designed to impart a load on the leaflet which simulates the actual loading within a heart valve. The results from a number of deflection tests are used to categorize individual leaflets, which data can be combined with other data regarding the characteristics of the leaflet to better select leaflets for assembly into a multi-leaflet heart valve. In one embodiment, the deflection test is combined with an intrinsic load test, and leaflets having similar deflection and intrinsic load values used in the same heart valve.

Abstract: A method for the manufacture of intravascular stents of bioresorbable material comprises the following steps:preparing a viscous solution of poly-.beta.-hydroxybutanoic acid as a bioresorbable polymeric material in a solvent,successively coating a male mold core with layers of the polymer solution in several steps by precipitation of the polymeric material by the solvent being evaporated and by the layer previously precipitated being dissolved at least partially for a homogeneous stent blank to build up,drawing the stent blank off the male mold core, andsubsequently treating the stent blank to finish the shaping of the stent.

Abstract: Improved, adaptable tissue-type heart valves and methods for their manufacture are disclosed wherein a dimensionally stable, pre-aligned tissue leaflet subassembly is formed and its peripheral edge clamped between and attached to an upper shaped wireform and a lower support stent. A variety of adaptable structural interfaces including suture rings, flanges, and conduits may be attached to the support stent with or without an outlet conduit disposed about the wireform to provide a tissue-type heart valve adaptable for use in either a natural heart or in mechanical pumping devices.

Abstract: The present invention includes a prosthetic heart valve having a stent and a piece of biocompatible material. The stent includes an inflow ring and a plurality of posts, each post extending from the ring to a post tip. The piece of material extends over the stent and substantially conforms to a profile of the stent. The piece of material includes a portion which extends adjacent a post tip. A clip is provided which has a shape generally conforming to the post tip to thereby clamp the portion of the piece of material to the post tip.

Abstract: A prosthetic heart valve is shown which incorporates a valve body design and leaflet pivot arrangements that minimize turbulence and shear stresses having a tendency to generate thrombosis. A valve body having an axially curved entrance that is smoothly joined to a generally cylindrical body of extended axial length provides excellent fluid flow characteristics when combined with leaflets that can assume orientations perfectly aligned with the downstream flow of blood. By constructing such a pyrocarbon valve body which receives a metal ring at an appropriate location, suture rings that permit the tissue annulus to directly contact the exterior surface of the cylindrical valve body are accommodated.

Abstract: A heart valve holder is provided for implanting a prosthetic heart valve in either an inflow (mitral or tricuspid) or an outflow (aortic or pulmonary) implantation. The valve holder may be repeatedly sterilized for multiple implantations. The valve holder includes holding members to securely hold the valve, a valve-sizing member to allow the holder to hold valves of various sizes, an over rotation stop to prevent the holder from impinging upon the valve leaflets, alignment members to align the holding members for receiving a valve, and means to rotate the valve without damaging the valve leaflets.

Abstract: The present invention includes a metallic coating on portions of the prosthesis to enhance the overall acceptability of the implantable device or fabric/sutures used to implant the prosthesis. The preferred metal is silver, which is applied to surfaces which are exposed to the heart tissue. The silver-treated portions of these devices inhibit or greatly reduce colonization of endocarditis-causing bacteria without impacting the overall biocompatibility of the device.

Abstract: This invention relates to bioprosthetic heart valve stents that are fashioned of bioresorbable materials. Such stents may be configured as sheaths or frames contoured to the shape of a valvular graft. The stents are eventually resorbed by the patent, leaving a functional "stentless" valve with improved hemodynamic characteristics compared to stented valve implants.

Abstract: A valve sizer having a movable element mounted to the distal end of a shaft. A valve sizing portion includes the movable element so that the valve sizing portion may be adjusted to correspond to a number of different available replacement valve sizes. An indicator mounted to the proximal end of the shaft indicates the valve size corresponding to the outer dimension of the valve sizing portion.

Abstract: The invention provides a sewing cuff assembly for mounting to the body of a heart valve prosthesis. The sewing cuff assembly comprises a resiliently deformed spring for exerting a force directed toward the orifice structure. When a torque is applied to the valve, the force results in a rotation-resisting torque sufficient to resist rotation during normal operation of the valve after implantation but low enough to permit assisted rotation, as during surgery.

Abstract: A surgical implement particularly useful for implanting a prosthetic valve in an excised annulus includes a manually grippable handle, and a suture retainer carried by the handle and having an outer face carrying a coiled spring whose coils define an annular array of slits each having opposed yielding surfaces for receiving and releasably retaining sutures between selected coils. Optimum spacing of the sutures according to the shape of the excised annulus is attained by providing reference ribs between selected coils of the spring, and also by making the outer annular face of the suture retainer of substantially the same shape as that of the excised annulus. Implements are described, with a suture retainer and without a suture retainer, including an illuminating device for artificially illuminating the working area. Also described is a method of implanting a prosthetic valve in a quick and efficient manner using such implements.

Abstract: A a blood-contacting medical device with improved biocompatibility. The device is coated with a layer of water-soluble heparin, overlaid by a porous polymeric coating through which the heparin can elute. 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 composite natural tissue heart valve prosthesis which may be mounted in a cloth-covered, generally anatomical stent is disclosed. The prosthesis includes three adjacent tanned heart valve leaflets of generally similar size, shape and symmetry that are attached to adjacent leaflets along their respective valve wall side edges such that there is substantial coaptation between said cusps.

Abstract: An artificial heart valve comprises a relatively rigid stent member having a first cylindrical shape and a flexible valve disposed in the stent member, the stent member being self-expandable to a second cylindrical shape and collapsible to its first cylindrical shape. The valve comprises a circular portion comprising a plurality of leaflets extending from the periphery of the circular portion towards the center thereof, the leaflets being configured to allow for flow of blood through the valve in one direction only. The diameter of the circular portion is substantially the same as the inside diameter of the stent member when the stent member is in its second cylindrical shape, the valve member being attached to the stent member.

Abstract: A natural tissue heart valve prosthesis mounted in a cloth-covered, generally anatomical stent is disclosed. The prosthesis includes an annular implantation flange attached to the exterior base portion of the stent between the inflow end and the outflow end of the stent base and a pericardium strip attached to at least a portion of the outflow rails of the prosthesis to generally inhibit abrasion between the cusps of the valve and the cloth covering of the stent structure.

Abstract: Sulfonated multiblock copolymers, and uses thereof, are disclosed. The sulfonated copolymers are useful for providing non-thrombogenic coatings, e.g., for medical devices, and for promoting cell growth, differentiation, or production of normal cell products. The sulfonated copolymers are also useful for administration of therapeutic agents.

Abstract: This invention comprises a method of using tubular material to replace an atrioventricular (AV) heart valve (i.e., a mitral or tricuspid valve, positioned between an atrial chamber and a ventricular chamber) during cardiac surgery. Preferably, the tubular material should be inherently tubular; i.e., it should be created in tubular form from its inception, rather than by using a longitudinal suture line or other seam to convert a flat sheet of material into a tubular shape. Suitable tubular materials include (1) biocompatible synthetic materials which are manufactured in tubular form, by methods such as extrusion or coating a cylindrical molding device, using material which is sufficiently thin and flexible to serve as leaflets in AV heart valves; and (2) a segment of submucosal tissue harvested from a small intestine, either from the patient who is undergoing the cardiac surgery, or from an animal or human cadaver if the harvested tissue is properly treated to reduce antigenicity.

Abstract: A stent for insertion into a heart wall for Trans Myocardial Revascularization (TMR) thereof. The TMR stent provides for the delivery of blood nutrients from a heart chamber into the heart wall and has an elongated body which may contain a cavity and openings through the elongated body from the cavity. The elongated body should be in fluid communication with the heart chamber. If a cavity and openings are provided, the openings are in fluid communication with the heart chamber, the cavity and the heart wall. The TMR stent may include an anchoring element integrally formed thereon for securing the TMR stent in the heart wall.

Abstract: A ventricular assist device includes a pair of valved conduits and a pumping portion connected by these conduits into the circulatory system of a host patient. The pumping portion and valved conduits are constructed and configured to minimize the number of material-surface transitions which blood must cross in flowing through the device. Also, the valved conduits include porcine xenograft valves, which are externally supported by stenting structure located outside of the blood-contacting flow path of the device. A flexible shape-retaining inner wall member of the valved conduits is impervious to blood, but defines a porous inner surface on which a stable biological interface may form. Also, this inner wall member is shaped with sinuses which do not replicate either the porcine sinuses from which the xenograft valves were taken, or human aortic sinuses.

Abstract: A holder for engaging a heart valve prosthesis during implantation includes a mechanism for attaching the device to the heart valve prosthesis. The heart valve prosthesis includes a circular valve body having an annulus with a substantially annular aperture therein. At least one movable occluder is carried in the aperture and is movable between an open position and a closed position. The attachment mechanism includes a member which couples to the suture cuff thereby affixing the device to the heart valve prosthesis. The attachment mechanism may be actuated to disengage the heart valve prosthesis.

Abstract: In general, the present invention comprises an holding apparatus for facilitating implantation of a prosthetic heart valve within a mammalian heart. The holding apparatus generally comprises a cage or enclosure having a heart valve prosthesis retention space defined therewith. The proximal end of the holding apparatus is releasably attached to the proximal end of the heart valve prosthesis such that, when the holding apparatus is advanced in a forward direction, a "pulling" force will be exerted upon the proximal end of the prosthesis, rather than a "pushing" force being exerted upon the distal end of the prosthesis.

Abstract: A support housing (1) for valve and closure members, in particular for heart valve prostheses, has a base ring (2) which carries at least two symmetrically offset posts (4/5) substantially oriented in the direction of the ring axis and linked together by curved strips (3) for securing at least two flexible webs (6/7). In order to produce with such a support housing a valve or closure member, in particular a heart valve prosthesis, which operates reliably even with different closing pressure differentials, i.e. in particular even under varying physiological stress conditions, the stent (1) is only retained in sections and with limited flexibility. For that purpose the free ends (4) of the posts have a rigid form, and/or the bases of the posts have a flexibility limited by stops, and/or the strips (3) have a flexibility limited by stops.

Abstract: A mechanical heart valve for implantation in a heart of a patient includes an orifice body having an outer circumference and defining a lumen for blood flow therethrough. At least one leaflet carried in the lumen of the orifice body is movable between an open position, allowing flow through the lumen, and a closed position blocking flow through the lumen. A flange ring around the outer circumference of the orifice body includes a plurality of suture holes defined therein. The suture holes are adapted for receiving a suture and thereby attaching the heart valve to tissue of the heart.

Abstract: A prosthetic heart valve is shown which incorporates a valve body design and leaflet pivot arrangements that minimize turbulence and shear stresses having a tendency to generate thrombosis. A valve body having an axially curved entrance that is smoothly joined to a generally cylindrical body of extended axial length provides excellent fluid flow characteristics when combined with leaflets that can assume orientations perfectly aligned with the downstream flow of blood. By constructing such a pyrocarbon valve body which receives a metal ring at an appropriate location, suture rings that permit the tissue annulus to directly contact the exterior surface of the cylindrical valve body are accommodated.

Abstract: An implantable prosthetic heart valve with a suturing ring having an interiorly disposed split ring of constant diameter for securing the suturing ring fabric to the heart valve body and providing a constant rotational torque for facilitating rotation of the heart valve body with respect to the suturing ring. The split ring is formed of a stiff band having opposed split ring ends that are drawn together and held in place by fixation cords. The split ring may include flanges extending in the inflow and/or outflow directions to inhibit passage of suture needles through inflow and/or outflow rim bands of the suturing ring fabric to encourage proper surgical installation.

Abstract: A canalicular implant for insertion through the punctum of the eye and the method of manufacture. The implant is fabricated by cutting suture-like material, such as catgut, of the appropriate diameter to the desired length. The ends of the implant are rounded and polished after cutting by abrasive polishing to remove any sharp edges and burrs formed by the cutting process. This produces an implant with various degrees of rounding at the ends depending on the duration and type of abrasive polishing used. The method of abrasive polishing may comprise tumble polishing, vibratory polishing, or other methods of agitation utilizing dry or wet media comprised of beads, forms, abrasive powders, or other similar substances or combinations of these media.

Abstract: A suture ring for a rotatable artificial heart valve apparatus has a ring member covered by a fabric material. A portion of the fabric material covers a portion of the inner surface of the ring member. At least one protuberance is formed on the inner surface of the ring member so as to mitigate the frictional resistance to rotation which results from compression of the fabric between the suture ring and the heart valve. Thus, desirable rotation of the heart valve relative to the suture ring is assured over a range of thicknesses of the fabric material.

Abstract: An improved set of stents for autologous tissue heart valves is provided. The stents are designed with the aid of a computer-aided-design (CAD) system, and nest within each other to securely clamp a piece of tissue which forms the leaflets of the heart valve. The geometrical features of the stents are designed to provide uniform nesting between the stents to prevent the formation of stress raisers on the tissue. Additionally, the windows in the stent posts are narrowed to prevent the suturing needle used during implantation of the valve from becoming lodged in the garter springs which clamp the outer stent to the inner stent. Finally, the sock covering the outer stent is bonded to the stent base at both upper and lower locations to isolate the bonds from the patient's blood flow.

Abstract: A device for engaging a heart valve prosthesis during implantation includes a heart valve prosthesis holder. The holder includes a distal engaging surface adapted for engaging the heart valve prosthesis. The distal engaging surface carries a compliant member which maintains an occluder of the heart valve in a closed position during implantation.

Abstract: The present invention relates to a heterologous total stentless mitral valve prosthesis for the use in mitral and tricuspid position which provides for better hemodynamic performance. This mitral valve prosthesis addresses the specific needs of flow and contractility, thereby prolonging durability. The heterologous total stentless mitral heart valve prosthesis of this present invention comprises one sewing ring, leaflets, and subvalvular apparatus having new chordal insertions which are fixed to or in between two heterologous pericardial patches. This heart valve prosthesis is obtained from heterologous mammals, such as swine, ovine, bovine, and moreover, the pericardial patches used may also be of synthetic material.

Abstract: This invention relates to bioprosthetic heart valve stents that are fashioned of bioresorbable materials. Such stents may be configured as sheaths or frames contoured to the shape of a valvular graft. The stents are eventually resorbed by the patient, leaving a functional "stentless" valve with improved hemodynamic characteristics compared to stented valve implants.