64 results about "Retrograde Flow" patented technology

A multiple-sided medical device comprises a closed frame of a single piece of wire or other resilient material and having a series of bends and interconnecting sides. The device has both a flat configuration and a second, folded configuration that comprises a self-expanding stent. The stent is pushed from a delivery catheter into the lumen of a duct or vessel. One or more barbs are attached to the frame of the device for anchoring or to connect additional frames. A covering of fabric or other flexible material such as DACRON, PTFE, or collagen, is sutured or attached to the frame to form an occlusion device, a stent graft, or an artificial valve such as for correcting incompetent veins in the lower legs and feet. A partial, triangular-shaped covering over the lumen of the device allows the valve to open with normal blood flow and close to retrograde flow.

A valve prosthesis device is disclosed suitable for implantation in body ducts. The device comprises a support stent, comprised of a deployable construction adapted to be initially crimped in a narrow configuration suitable for catheterization through the body duct to a target location and adapted to be deployed by exerting substantially radial forces from within by means of a deployment device to a deployed state in the target location, and a valve assembly comprising a flexible conduit having an inlet end and an outlet, made of pliant material attached to the support beams providing collapsible slack portions of the conduit at the outlet. The support stent is provided with a plurality of longitudinally rigid support beams of fixed length. When flow is allowed to pass through the valve prosthesis device from the inlet to the outlet, the valve assembly is kept in an open position, whereas a reverse flow is prevented as the collapsible slack portions of the valve assembly collapse inwardly providing blockage to the reverse flow. The device is configured so that retrograde flow will be altered from laminar flow and directed towards the leaflets to effect closing.

An evacuation sheath assembly and method of treating occluded vessels which reduces the risk of distal embolization during vascular interventions is provided. The evacuation sheath assembly includes an elongated tube defining an evacuation lumen having proximal and distal ends. A proximal sealing surface is provided on a proximal portion of the tube and is configured to form a seal with a lumen of a guided catheter. A distal sealing surface is provided on a distal portion of the tube and is configured to form a seal with a blood vessel. Obturator assemblies and infusion catheter assemblies are provided to be used with the evacuation sheath assembly. A method of treatment of a blood vessel using the evacuation sheath assembly includes advancing the evacuation sheath assembly into the blood vessel through a guide catheter. Normal antegrade blood flow in the blood vessel proximate to the stenosis is stopped and the stenosis is treated. Retrograde blood flow is induced within the blood vessel to carry embolic material dislodged during treating into the evacuation sheath assembly. If necessary to increase retrograde flow, the coronary sinus may be at least partially occluded. Alternatively, antegrade flow may be permitted while flow is occluded at the treatment site.

Apparatus and methods for treatment of stroke are provided. In a preferred embodiment, the present invention disposes at least one catheter having a distal occlusive member in the common carotid artery of the hemisphere of the cerebral occlusion. Retrograde flow may be provided through the catheter to effectively control cerebral flow characteristics. Under such controlled flow conditions, a thrombectomy device may be used to treat the occlusion, and any emboli generated are directed into the catheter.

A noninvasive patient-specific method is provided to aid in the analysis, diagnosis, prediction or treatment of hemodynamics of the cardiovascular system of a patient. Coronary blood flow and pressure can be predicted using a 3-D patient image-based model that is implicitly coupled with a model of at least a portion of the remaining cardiovascular system. The 3-D patient image-based model includes at least a portion of the thoracic aorta and epicardial coronaries of the patient. The shape of one or more velocity profiles at the interface of the models is enforced to control complex flow features of recirculating or retrograde flow thereby minimizing model instabilities and resulting in patient-specific predictions of coronary flow rate and pressure. The invention allows for patient-specific predictions of the effect of different or varying physiological states and hemodynamic benefits of coronary medical interventions, percutaneous coronary interventions and surgical therapies.

An expandable venous valve having a support structure that configured to enlarge the area adjacent to the valve structure such that the flow patterns of retrograde flow are modified in a way that facilitates the flushing of the pockets at the base of the valve area to prevent stagnation of bodily fluid, which in the venous system, can lead to thrombus formation. The enlarged pocket areas can be created by forming an artificial sinus adjacent the valve structure in an unsupported section of vessel wall between two support frame section or the support frame can comprise an expanded-diameter intermediate or proximal section that forms an artificial sinus adjacent the valve structure. In another group of embodiments, the attachment pathway between opposing leaflets and the support frame and/or vessel wall comprises a proximal portion that places the leaflets in extended contact with one another and a distal portion forms a large angle with respect to the adjacent walls such that a large pocket is created at the base of the leaflets. In one embodiment, the attachment pathway extends distally along a pair of substantially parallel longitudinal attachment struts to create an extended leaflet contact area, then angles circumferentially and distally from the former along distal attachment struts to define the bottom edge of the leaflets.

Devices, systems, and methods employ an implant that is sized and configured to attach to the annulus of a dysfunctional heart valve annulus. In use, the implant extends across the major axis of the annulus above and/or along the valve annulus. The implant reshapes the major axis dimension and/or other surrounding anatomic structures. The implant restores to the heart valve annulus and leaflets a more functional anatomic shape and tension. The more functional anatomic shape and tension are conducive to coaptation of the leaflets, which, in turn, reduces retrograde flow or regurgitation. The implant improves function to the valve, without surgically cinching, resecting, and/or fixing in position large portions of a dilated annulus, or without the surgical fixation of ring-like structures.

The present invention concerns a novel stent and a method for communicating oxygenated blood directly from the left ventricle to the coronary sinus to provide retrograde perfusion to the myocardium. The stent is placed substantially within the coronary sinus with its trailing end protruding into the right atrium and the leading end protruding into the left ventricle. The stent has a smaller passageway at the trailing (right ventricular) end and at the leading (left ventricle) end, and has a covering at the trailing end. The smaller passageway and the cover at the trailing end to promote retrograde flow into the venous system of the heart and specifically the myocardium of the left ventricle and to reduce a significant left-to-right shunt.

Apparatus and methods are described for effective removal of emboli or harmful fluids during vascular procedures, such as angiography, balloon angioplasty, stent deployment, laser angioplasty, atherectomy, intravascular ultrasonography and other therapeutic and diagnostic procedures. A catheter with an occluder mounted at its distal end creates an occlusion proximal to the lesion. The catheter provides a pathway for introducing a treatment catheter. Prior to, during or subsequent to the procedure, suction is activated to establish retrograde flow to remove emboli from the site. Additionally, a thin catheter with a distal fluid ejection nozzle maybe introduced distal to the treatment site to rinse emboli from the treatment site. The suction flow and/or ejected fluid flow may be varied in a pulsatile manner to simulate regular blood flow and/or perturb settled emboli into being captured that may otherwise not be collected. The method establishes a protective environment before any devices enter the site to be treated.

Devices, systems and methods retain a native heart valve leaflet to prevent retrograde flow. The devices, systems, and methods employ an implant that, in use, rests adjacent a valve annulus and includes a retaining structure that is sized and shaped to overlay at least a portion of one or more native valve leaflets. The retaining structure retains the leaflet or leaflets it overlays, to resist leaflet eversion and/or prolapse. In this way, the implant prevents or reduces regurgitation. The implant does not interfere significantly with the opening of and blood flow through the leaflets during periods of antegrade flow.

Disclosed is a pressure sensitive prosthesis that includes a tubular member having a passageway extending therethrough and a sleeve attached about one end of the tubular member. The sleeve functions as a one-way valve to permit fluid flowing through the sleeve lumen in a first direction and under a first pressure, while collapsing in response to fluid flowing in a second direction when the pressure thereof exceeds that of the first direction or pressure. One aspect of the invention includes an esophageal anti-reflux expandable prosthesis wherein the sleeve is adapted to invert back through the tubular stent frame to permit belching or vomiting (fluid or materials under a third, significantly higher pressure). Another aspect of the invention includes a tubular drainage stent, such as a biliary or urethral stent in which the sleeve opens to permit passage of fluids, then collapses to prevent retrograde flow.

Prosthetic valves for regulating fluid flow are provided. The valves have at least one leaflet that includes a plurality of pores that allow a quantity of retrograde flow to pass through the leaflet when the valve is in a closed configuration.

The present invention is directed to a proximal catheter assembly that is configured to facilitate aspiration through a catheter lumen. The proximal catheter assembly enables natural aspiration to be achieved within the catheter lumen, for example, using an arterial-venous shunt, and further enables suction-assisted aspiration or infusion to be applied through the catheter lumen. This allows a physician to provide a substantially continuous level of retrograde flow within a vessel during a medical procedure without damaging the vessel wall, while providing the option of suction-assisted aspiration, when necessary, to further influence the level of aspiration within the vessel.

A medical fluid flowline connector comprised of axially aligned relatively rotatable male and female Luer parts and an axially compressible elastomeric seal therebetween. An elastomeric stopper may be provided in the female Luer, the stopper having a swabbable end urged outwardly of the female Luer. The stopper is guided on an axially extending elongated flow conducting insert which has an end which contacts a deformable slit in the swabbable end of the stopper to ensure deformation and opening of the slot as a male Luer at the end of a fluid flowline is pushed against the stopper. The stopper skirt is deformed and displaced into annular space between the female Luer and the insert, the stopper having bellows like walls which engage the female Luer and insert. A retrograde flow preventer may be positioned in the fluid flow path comprising a resilient member having a perforation which remains closed when its exterior surface is exposed to retrograde flow of medication or blood and which may open when its interior surface is exposed to sufficient negative flow pressures as when drawing blood.

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.