421results about How to "Prevent thrombosis" patented technology

The invention features polymeric biomaterials formed by nucleophilic addition reactions to conjugated unsaturated groups. These biomaterials may be used for medical treatments.

The present invention involves a blood pump having a pump housing with an internally disposed rotor that collectively provide a dual inflow capability which prevents thrombus formation and reduces hemolysis during use.

Stents with coatings comprising a combination of a restenosis inhibitor comprising an HMG-CoA reductase inhibitor and a carrier. Also provided are methods of coating stents with a combination of an HMG-CoA reductase inhibitor and a carrier. A preferred example of a restenosis inhibitor is cerivastatin. The stent coatings have been shown to release restenosis inhibitors in their active forms.

It is an object of the present invention to realize a small and light blood pump that can control thrombosis and moreover, endure a prolonged use.

A blood pump comprising an impeller, a casing having a suction inlet and a delivery outlet and rotatably encasing the impeller, a magnetic drive means for rotating the impeller by magnetically acting from outside of the casing on a magnet that the impeller includes, a magnetic attraction force adjustment means for adjusting the attraction force by said magnetic action, a control means for rotating speed of said magnetic drive means, and a pair of pivot bearings for supporting pivots at both ends of the impeller rotation shaft, wherein the distance between bearing faces of said both pivot bearings is set longer than the length of the rotation shaft of the impeller and the rotation speed of the impeller is controlled to a predetermined speed by said control means for rotating speed so as to levitate the impeller in the blood flow in the casing and to maintain out of contact between the pivots at both ends of the rotation shaft of the impeller and the bearing face of said both pivot bearing.

In accordance with the present invention, a distal protection and embolic material retrieval device with improved apposition to both large and small vessel walls of varying geometries for enhancing the filtering of embolic material during intravascular procedures while allowing for the passage of blood is provided. The device includes a filter basket designed to maximize apposition of the filtering portion to that of the vessel wall and may include struts which provide circumferential support to the filtering membrane and thereby minimizing or eliminating in-folding of the filter basket. Thin film materials may also be utilized for the filtering membrane of the filter basket. In addition one can incorporate biological and/or pharmaceutical agents in combination with the present invention.

The invention provides a medical device having a catheter and first and second expandable members. The device may be used for protection against stroke by inserting the catheter into a carotid artery, locating the first expandable member within a common carotid artery, locating the second expandable member within an external carotid artery, expanding the first expandable member to occlude the common carotid artery, and expanding the second expandable member to at least partially obstruct the external carotid artery. By this method antegrade blood flow in the internal carotid artery stops.

Polymeric drug formulations containing a non-releasing single-phase dispersion of a water-soluble drug in a water-insoluble tissue-compatible polymer matrix. Polymeric drug formulations are also disclosed containing a single-phase dispersion of a water-soluble drug and a water-insoluble tissue-compatible polymer matrix, and a second, phase-disrupting polymer that is non-miscible with the tissue-compatible polymer and is present in an amount sufficient to form phase-separated microdomains of the second polymer in the tissue-compatible polymer matrix, so that the release rate of the water-soluble drug from the tissue-compatible polymer matrix is related to the amount of the second polymer. Methods of preparing the polymeric drug formulations are also described, as well as methods for site-specific drug delivery utilizing the polymeric drug formulations.

In an artificial heart valve for the replacement of an aortic or a mitral valve, including an annular body, which is provided at its outer circumference with means for mounting the artificial valve in place by surgical procedures and which defines in its interior a blood flow passage in which valve flap elements are pivotally supported so as to open or close the blood flow passage depending on their pivot positions, the annular body includes circumferentially spaced projections extending into the flow passage and being provided at their inner ends with pivot joints on which the valve flap elements are pivotally supported.

The present invention relates to a vascular stent that includes an expandable stent defining an interior compartment, a first polymeric layer exposed to the interior compartment defined by the stent, the first layer comprising an agent that promotes re-endothelialization, an agent that inhibits thrombosis, or a combination thereof, and a second polymeric layer at least partially external of the stent, the second layer being adapted for contacting a vascular surface and being characterized by pores that are substantially impermeable to vascular smooth muscle cell migration. Method of making and using the vascular stent are also disclosed.

A biodegradable antithrombotic conjugate having heparin and other anti-thrombotic moieties are introduced as side chains to the polymer backbone modified by click chemistry. Various bioabsorbable monomers and dimers such as valerolactone may be used in the monomer derivation, homo- and co-polymerization, and the conjugation with a biologically active molecule by click chemistry. A coating comprising a biocompatible and bioabsorbable polymer anti-thrombotic conjugate is applied to at least a portion of an implantable device to prevent or reduce the formation of thrombosis on the surface of the implantable device. A first or sub-layer of the coating is prepared by mixing a polymeric material and a biologically active agent with a solvent, thereby forming a homogeneous solution. A second or outer layer comprising the present anti-thrombotic conjugate may be applied over the inner drug-containing layers using, for example, a dip coating or spray coating process.

A prosthetic valve for regulating fluid flow through a body vessel is provided. The valve includes an expandable support frame and a valve leaflet, and includes at least one opening that permits a controlled amount of retrograde flow through the valve when the valve is in a closed configuration.

The present device has increased longitudinal flexibility in a stent by having some curved sections of each circumferential set of strut members being unconnected to the curved sections of the adjacent circumferential set of strut members with the other curved sections being connected by highly flexible, undulating longitudinal connecting links. The present device prevents flaring of the unconnected strut members by having a shorter longitudinal length for the unconnected strut members, and may have generally shorter longitudinal lengths for all the strut members in the circumferential sets of strut members at the stent ends to reduce the tendency for end flaring of the stent. Finally, the stent demonstrates that the flexible longitudinal connecting links of the curved sections of the sets of strut members are connected at a point that is close to the line where the diagonal sections join the curved sections, thus further reducing the propensity for end flaring.

A hemodialysis and vascular access system comprises a subcutaneous composite PTFE silastic arteriovenous fistula having an indwelling silastic venous end which is inserted percutaneously into a vein and a PTFE arterial end which is anastomosed to an artery. Access to a blood stream within the system is gained by direct puncture of needle(s) into a needle receiving site having a tubular passage within a metal or plastic frame and a silicone upper surface through which needle(s) are inserted. In an alternate embodiment of the invention, percutaneous access to a blood stream may be gained by placing needles directly into the system (i.e. into the PTFE arterial end). The invention also proposes an additional embodiment having an arterialized indwelling venous catheter where blood flows from an artery through a tube and a port into an arterial reservoir and is returned to a vein via a port and a venous outlet tube distinct and distant from the area where the blood from the artery enters the arterial reservoir. The site where blood is returned to the vein is not directly fixed to the venous wall but is free floating within the vein. This system provides a hemodialysis and venous access graft which has superior longevity and performance, is easier to implant and is much more user friendly.

A modified annexin protein, preferably annexin V, is used to prevent thrombosis without increasing hemorrhage. Annexin binds to phosphatidylserine on the outer surface of cell membranes, thereby preventing binding of the prothrombinase complex necessary for thrombus formation. It does not, however, affect platelet aggregation necessary for hemostasis. The modified annexin molecule can be a homodimer of annexin, an annexin molecule coupled to one or more polyethylene glycol chains, or an annexin molecule coupled to another protein. By increasing the molecular weight of annexin, the modified annexin is made to remain in circulation for sufficient time to provide a sustained therapeutic effect.

An ablation electrode is mounted on the distal end of a catheter with a first portion inside and a second portion outside the catheter. The second portion is adapted to have a surface that makes maximum contact with a tissue to be ablated, leaving a minimum area not covered by the tissue and potentially exposed to blood. The first portion is adapted to provide an extended surface area for efficient exchange of heat with a coolant flowing inside the catheter. Outlets provided near the area not covered by the tissue in the second portion prevents blood from getting close to or come directly in contact with the area, thereby greatly reducing formation of dangerous blood clots. The minimizing of an electrical circuit through blood greatly reduces wasted power into the electrode so that the efficiently cooled electrode is not burdened. The catheter preferably has multiple electrodes with similar features.

Substantially pure dimers of Apolipoprotein AI-Milano (APO-AI-M/APO AI-M) were isolated from plasma and characterized. Apolipoprotein AI-M dimer can also be produced in a recombinant Escherichia coli system. Pharmaceutical compositions comprising the ApoAI-AI-M/ApoAI-M are described. Patients with atherosclerosis or cardiovascular diseases can be treated with the dimer. Medicaments containing the dimer can also be used to prevent thrombosis in different clinical circumstances, both at the arterial and at the venous level. The dimer can also act as a prodrug for the monomer.

A catheter apparatus is provided that includes a tubular body having a distal end. The body defines first and second lumens. The first lumen has a first adapter that includes a first valve biased to seal the proximal end. The first lumen defines a first lateral port and the second lumen defines a second lateral port. A push rod is connected to the first valve for corresponding movement therewith and extends to a tip. The tip includes a first member extending into the first lumen and a second member extending into the second lumen such that the first member seals the first lateral port and the second member seals the second lateral port in a closed position of the tip. The first valve is engageable such that fluid communication is established between the proximal end of the first lumen and the first lumen, and the first and second members move to an open position whereby fluid communication is established. The first and second lumens may be coaxial whereby the first lumen has a first port that seals a second port of the second lumen.

The present invention provides a drug-eluting stent, wherein the stent is coated with one or more non-mucleotide P2Y₁₂ receptor antagonist compounds or a pharmaceutically acceptable salt, solvate, or hydrate thereof. When the stent is placed in a narrowed or damaged arterial vessel, a therapeutically effective amount of the P2Y₁₂ receptor antagonist compound is eluted continuously from the stent to the local environment of the stent. The P2Y₁₂ receptor antagonist compound-eluting stents are useful in preventing thrombosis and restenosis, and are effective in inhibiting the contraction of vascular smooth muscle cells, inhibiting cell proliferation, and reducing inflammation.

A blood access for dialysis includes a radially distensible support structure having an open lattice structure defining a support wall having interstitial open areas and defining exterior and luminal wall surfaces; a first porous polymeric portion having a plurality of pores, the first porous polymeric portion being securably disposed over at least a portion of the exterior wall portion of the support structure; a second porous polymeric portion having a plurality of pores, the second porous polymeric portion being securably disposed over at least a portion of the luminal portion of the support structure; and a biodegradable and/or bioabsorbable material disposed within the pores of the first polymeric portion and/or pores of the second polymeric portion.

A method of forming a tissue equivalent is described. A length of polyester tube is threaded over a mandrel (H) and attached at either end by clips at A and D. A block (F) is then screwed into place. The polyester is then pre-soaked by injecting through Tap (2) an acidified collagen solution for approximately one hour. After a suitable period of time the excess solution is aspirated off. Following this stage, a second, alkaline solution is injected into the apparatus which contains smooth muscle cells (SMC). Thus, neutralisation of the collagen impregnated within the fabric of the tube occurs leading to spontaneous fibrillogenesis within the interstices of the cloth, eliminating the risk of delamination. The apparatus is then incubated. The collagen contracts down onto the fabric tube and the cell-impregnated gel becomes incorporated into the presoaked collagen. The pre-impregnated collagen and the collagen provided in the aqueous mixture contract down as one into a coherent whole with the SMC. The tissue equivalent is then lined with endothelial cells and the apparatus again incubated and fed at increasing intraluminal pressures applied either statically or dynamically. This is believed to cause the vessel to become preconditioned to the pressure it will work under as an implant. This allows organization of the basement membrane which in turn promotes EC attachment and theoretically prevents smooth muscle cell hyperplasia.

A method is provided for increasing blood flow in or about a cardiac structure to prevent thrombosis. One step of the method includes providing an implantable sprayer having an elongated tubular body with proximal and distal end portions. The distal end portion includes at least one opening and an anchoring mechanism. The distal end portion of the implantable sprayer is inserted into a cardiac chamber that includes the cardiac structure. The anchoring mechanism is then deployed so that the distal end portion of the implantable sprayer is secured in or about the cardiac structure. Next, the proximal end portion is anastomosed with an artery so that blood flows through the elongated tubular body of the implantable sprayer and is sprayed out of the at least one opening to continuously circulate blood in or about the cardiac structure.