News Column

"Stentless Aortic Valve Replacement with High Radial Strength" in Patent Application Approval Process

July 3, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- A patent application by the inventors Lashinski, Randall T. (Santa Rosa, CA); Bishop, Gordon B. (Santa Rosa, CA), filed on September 26, 2013, was made available online on June 19, 2014, according to news reporting originating from Washington, D.C., by VerticalNews correspondents.

This patent application is assigned to Direct Flow Medical, Inc.

The following quote was obtained by the news editors from the background information supplied by the inventors: "The malfunctioning of an aortic valve results in cardiac insufficiency and hence in a situation that is potentially fatal for the patient. For repair of such a defect, artificial aortic valves have been developed which are implanted as a substitute for the damaged valve in complex and risky open-heart surgery (sternotomy). The operation becomes particularly difficult when there is strong calcareous degeneration on the natural valve because painstaking attention must be paid during removal in order to ensure that calcification particles will not enter the blood circulation and cause there thromboses at other sites in the body. It is common to fasten the replacement valves--which are either mere engineering products or derived from porcine or other tissue valves--by suturing in the place of the removed valve.

"There are numerous approaches in the development of methods simplifying this complex procedure of aortic-valve replacement in terms of both the surgical technique and the discomfort and strain for the patient, aiming at a minimally invasive technique of replacement of the aortic valve. In these approaches, the operation is performed via the femoral artery or even through the groin.

"In view of the very restricted possibilities of access in the aortic arch, it is inevitable to adopt complex surgical strategies, firstly for explantation of the calcified aortic valve and secondly for implantation of an artificial valve in situ. Apart from all difficulties involved in the surgical operation--even though minimally invasive surgery is concerned that operates on advanced catheter technology--a maximum of concentration and above all a steady hand is demanded from the surgeon, specifically as the individual steps of surgical handling are within the millimeter range and there below. With the minimally invasive operation being performed with a sustained natural function of the heart, it is moreover important to carry out the operation as quickly as possible in order to keep the strain on the cardiac system at a minimum, which means that an operation of this kind is performed under a certain pressure in terms of time.

"A special aspect is the ablation of the calcified aortic valve that must be removed completely from the aorta as quickly as possible, without lesion of adjoining unaffected tissue regions, specifically as the ablation involves mostly the application of mechanically acute cutting tools. Furthermore, it is important to ensure that severed tissue fragments or calcification particles will be extracted from the blood stream without any residues so as to avoid the occurrence of embolism or thromboses."

In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors' summary information for this patent application: "The present invention is based on the task of solving the problem configuring a device for replacement of an aortic or other valve on the human heart or peripheral vascular system by a minimally invasive technique. A device with a high radial strength may provide an ideal implant for heavily calcified aortic valves. Conventional treatment includes surgical replacement or a percutaneous balloon valvuloplasty. The second option is an insertion of a balloon catheter to the calcified aortic valve and inflation to dilation of the native valve to push the calcium aside. Though this technique is successful acutely, the restinosis rates are shown to be about 80% at twelve months. Some physicians in Europe believe this to be a technique to use in maintaining aortic flow in patients with out a surgical option. By this technique a patient may be treated with a balloon valvuloplasty up to three times providing an improved quality of life without a surgical intervention. It therefore stands to reason that during this acute restinosis after balloon valvuloplasty, if the calcium can be held back by a high radial strength device, a longer term therapy may be possible with a high strength device. This allows a larger patient population to be treated with a less invasive method and a more rapid recovery time. It may also eliminate the need for by-pass. This procedure may be completed under fluoroscopy, surface, transesophageal or transluminal echo. It will be desirable to monitor the patient's vital signs before, during and after the procedure. These may include blood pressures in relative chambers of the heart, aortic outflow, heart rate, breathing rates and blood chemistry. Blood thinners, heparin, aspirin and other drugs may be required to optimize blood before during and after the procedure.

"Accordingly, one embodiment of the present invention comprises a cardiovascular prosthetic valve that includes an inflatable cuff. The cuff comprises at least one inflatable channel that forms, at least in part, a distal inflatable toroidal structure and a proximal inflatable toroidal structure. The inflatable cuff also comprises a waist that extends between the distal inflatable toroidal structure and the proximal inflatable toroidal structure. A valve is coupled to the inflatable cuff. The valve is configured to permit flow in a first axial direction and to inhibit flow in a second axial direction opposite to the first axial direction.

"Another embodiment of the present invention comprises a prosthetic valve for replacing an aortic valve positioned between the left ventricle and the aorta of the heart. The valve includes an inflatable structure that has a distal end and a proximal end. A valve member is coupled to the inflatable structure. The valve member is positioned generally between the distal and proximal ends of the inflatable structure. The distal end of the inflatable structure is configured to be positioned within the left ventricle and the proximal end of the inflatable structure is configured to be positioned within the aorta.

"Another embodiment of the present invention comprises a cardiovascular prosthetic valve that comprises an inflatable body. The inflatable body has at least a first inflatable chamber and a second inflatable chamber that is not in fluid communication with the first inflatable chamber. The inflatable body is to form, at least in part, a generally annular ring. A valve is coupled to the inflatable body. The valve is configured to permit flow in a first axial direction and to inhibit flow in a second axial direction opposite to the first axial direction. A first inflation port is in communication with the first inflatable chamber. A second inflation port is in communication with the second inflatable chamber.

"Another embodiment of the present invention comprises a cardiovascular prosthetic valve that includes a cuff and an inflatable structure. The cuff has a distal end and a proximal end. The inflatable structure is coupled to the cuff and has at least one inflatable channel that forms a toroidal structure. A valve is coupled to the cuff. The valve is configured to permit flow in a first axial direction and to inhibit flow in a second axial direction opposite to the first axial direction. The distal end of the cuff has a non-circular cross-section with respect to the flow. The non-circular cross-section is configured to affect the performance of an adjacent valve.

"Another embodiment of the present invention comprises a cardiovascular prosthetic valve that includes a flexible cuff having a distal end and a proximal end. An inflatable structure is coupled to the cuff and has at least one inflatable channel that forms a toroidal structure. A valve is mounted to the cuff. The valve is configured to permit flow in a first axial direction and to inhibit flow in a second axial direction opposite to the first axial direction. At least one anchor is moveable between a first position in which the anchor extends in a radial direction to engage an adjacent anatomical structure and a second position in which the anchor has a reduced radial profile.

"Another embodiment of the present invention comprises a cardiovascular prosthetic valve that includes an inflatable body. A valve is coupled to the body. The valve is configured to permit flow in a first axial direction and to inhibit flow in a second axial direction opposite to the first axial direction. At least two control wires are detachably coupled to the inflatable body.

"Yet another embodiment of the present invention comprises a cardiovascular prosthetic valve that includes an inflatable body comprising at least one inflation channel. A valve is coupled to the body. The valve is configured to permit flow in a first axial direction and to inhibit flow in a second axial direction opposite to the first axial direction. An inflation port is in communication with the at least one inflatable channel. A plug is positioned within the inflation port. An inflation tube extends through the inflation tube in communication with the at least one inflation channel. A balloon is coupled to the inflation tube. The balloon is configured to expand between a first, inflated position in which the balloon prevents the inflation tube from decoupling from the inflation port and a second, deflated position in which the inflation tube can be decoupled from the inflation port.

"Another embodiment of the present invention comprises a method of implanting a prosthetic valve within a heart. A prosthetic valve comprising an inflatable structure is translumenally advanced to a position proximate a native valve of the heart. A portion of the inflatable structure that is distal to the native valve is inflated. A portion of the inflatable structure that is proximal to the native annular valve is inflated.

"Another embodiment of the invention involves a method of implanting a prosthetic valve within the heart that comprises translumenally advancing a prosthetic valve that has an inflatable structure to a position proximate a native valve of the heart. A distal portion of the inflatable structure is inflated. The valve is proximally retracted to seat the distal portion of the inflatable structure against a distally facing portion of the native valve.

"Another embodiment of the invention comprises a method of implanting a prosthetic valve within the heart. A prosthetic valve comprising an inflatable structure is advanced, translumenally, to a position proximate a native valve of the heart. A first chamber of the inflatable structure is inflated. A second chamber of the inflatable structure is independently inflated.

"Another embodiment of the present invention relates to a method of implanting a prosthetic valve within the heart in which a prosthetic valve comprising an inflatable structure is advanced translumenally to a position proximate a native valve of the heart. The inflatable structure is inflated to deploy the prosthetic valve. The prosthetic valve is stapled or sutured to an adjacent anatomical structure.

"Another embodiment of the present invention is a method of treating a patient. The method comprises translumenally advancing a prosthetic valve to a position proximate a native valve of the heart, fully deploying the prosthetic valve at the cardiovascular site, testing a performance characteristic of the prosthetic valve, at least partially reversing the deployment of the prosthetic valve, repositioning the prosthetic valve; and re-deploying the prosthetic valve.

"Another embodiment of the present invention involves advancing a deployment catheter to a position proximate a native valve of the heart, the deployment catheter comprising an inflation tube and a prosthetic valve comprising an inflatable structure in communication with the inflation tube, inflating the inflatable structure with the inflation tube, removing the deployment catheter from the patient while the inflation tube remains coupled to the inflatable catheter, advancing a removal catheter over the inflation tube, deflating the inflatable structure, retracting the prosthetic valve into the removal catheter; and withdrawing the prosthetic valve and the removal catheter from the patient.

"Another embodiment of the invention comprise a method of treating a patient that includes advancing a deployment catheter to a position proximate a native valve of the heart, the deployment catheter comprising a prosthetic valve and a linking member coupled to the prosthetic valve, deploying the prosthetic valve, removing the deployment catheter from the patient while the linking member remains coupled to the prosthetic valve, advancing a removal catheter over the linking member, retracting the prosthetic valve into the removal catheter; and withdrawing the prosthetic valve and the removal catheter from the patient.

"Another embodiment of the present invention comprises identifying a patient with a minimum cross-sectional flow area through an aortic valve of no greater than 0.75 square cm, enlarging the minimum cross-sectional flow area through the valve; and deploying a prosthetic valve which provides a minimum cross-sectional flow area of at least about 1.75 square cm.

"Yet another embodiment of the preset invention involves a method of treating a patient. The method comprises inflating an inflatable structure of a temporary valve at a cardiovascular site in fluid communication with a native valve, translumenally removing at least a portion of the native valve, deploying a prosthetic valve to compliment or replace a native valve, and removing the temporary valve.

"Another embodiment of the present invention comprises a method of performing a procedure on a beating heart. In the method, a temporary valve is positioned in series fluid flow with a native valve. An inflatable prosthetic valve is deployed upstream of the temporary valve. The temporary valve is then removed.

"Yet another embodiment of the present invention comprises a temporary heart valve catheter, for enabling minimally invasive procedures on a valve in a beating heart. The catheter includes an elongate, flexible catheter body, having a proximal end and a distal end, a valve on the distal end, the valve comprising an inflatable structure; and at least one link between the catheter and the valve to prevent detachment of the valve from the catheter.

"Another embodiment of the present invention comprises a method of in situ formation of a prosthetic valve support. A prosthetic valve is attached to a flexible support component which is incapable of retaining the valve at a functional site in the arterial vasculature. The support component extends both proximally and distally of the base of the valve. The valve is positioned at the site. The flexible support component is supplemented to increase the rigidity of the support component sufficiently to retain the valve at the site.

"Another embodiment of the present invention involves an implantable prosthetic valve that has an in situ formable support structure. The valve comprises a prosthetic valve, having a base and at least one flow occluder. A first flexible component is incapable of retaining the valve at a functional site in the arterial vasculature. The first component extends proximally of the base of the valve. A second flexible component is incapable of retaining the valve at a functional site in the arterial vasculature. The second component extends distally of the base of the valve. At least one rigidity component combines with at least one of the first and second flexible components to impart sufficient rigidity to the first or second components to retain the valve at the site.

"There is provided in accordance with one embodiment of the present invention, a method of treating a patient. The method comprises deploying a temporary valve at a cardiovascular site in fluid communication with a native valve. At least a portion of the native valve is transluminally removed, and a prosthetic valve is deployed to complement or replace the native valve. The temporary valve is thereafter removed.

"In one embodiment, the deploying a temporary valve step may comprise transluminally advancing the temporary valve to the site while the valve is in a first, reduced cross sectional configuration, and transforming the valve to a second, enlarged configuration to enable the valve to function at the site. The removing the temporary valve step may comprise transforming the valve in the direction of the first configuration, and transluminally removing the temporary valve. In certain embodiments, the temporary valve is permanently affixed to a temporary valve deployment catheter, to facilitate valve removal. The method may be accomplished on a beating heart.

"The deploying a temporary valve step may comprise deploying a valve with tissue leaflets. Alternatively, the deploying a temporary valve step may comprise deploying a valve with synthetic leaflets. The valve may be supported within a self expandable stent, a balloon expandable stent, or an inflatable cuff. The removing the temporary valve step may comprise retracting the valve into a tubular sheath.

"The transluminally removing at least a portion of the native valve step may comprise mechanically cutting native valve tissue. Mechanical cutting may be accomplished with an axially reciprocating cutter, or a rotational cutter. Cutting or decalcification may also be accomplished using a thermal source, such as a laser, or ultrasound.

"The method may additionally comprise the step of capturing embolic material dislodged into the blood stream from the valve procedure. This may be achieved by filtration or extraction of the material through an aspiration process.

"In accordance with another embodiment of the present invention, there is provided a method of performing a procedure on a beating heart. The method comprises the steps of positioning a temporary valve in series fluid flow with a native valve, and performing a procedure on the native valve. The temporary valve is thereafter removed. The valve may be the aortic valve, the mitral valve, or other valves. The procedure may be a valve repair, or a valve replacement.

"In accordance with a another embodiment of the present invention, there is provided a temporary heart valve catheter, for enabling minimally invasive procedures on a valve in a beating heart. The catheter comprises an elongate flexible catheter body, having a proximal end and a distal end. A valve is carried by the distal end. At least one link is provided between the catheter and the valve to prevent detachment of the valve from the catheter. The valve may be supported by a support frame, which is connected to a pull wire or wires extending axially throughout the length of the catheter. Axial tensioning of the pull wire relative to the catheter body deploys the valve into its functional configuration. Proximal retraction of the pull wire causes the valve to reduce in cross section and draw into the distal end of the catheter, such as for placement or removal. The link may comprise a connection between the pull wire and a valve support.

"In all of the foregoing embodiments, the formed in place stentless valve support of the present invention preferably retains essentially full functionality under a transverse load of at least about 2 lbs, often under loads of at least about 3 lbs, and in some cases loads of at least about 4 lbs. In some constructions of the present invention the stentless formed in place valve support will retain full functionality under transverse load of at least about 5 lbs. The formed in place valve support will preferably have a transverse displacement of no greater than about 0.2 inches, under a load of at least about 3 lbs, often at least about 4 lbs, and in certain embodiments in excess of about 6 lbs or 7 lbs.

"Further features and advantages of the present invention will become apparent from the detailed description of preferred embodiments which follows, when considered together with the attached drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 illustrates the displacement or transverse crushing in inches, as a function of applied force, for a stent and a cast in place valve support.

"FIG. 2 is a front elevational perspective view of a balloon expandable stent based valve system.

"FIG. 3A is a perspective schematic view of a formed in place support in accordance with the present invention.

"FIG. 3B is a cross sectional schematic view of the formed in place support of FIG. 3A.

"FIG. 4 is a perspective schematic view of an alternate formed in place support in accordance with the present invention.

"FIG. 5A is a perspective schematic view of an alternate formed in place support in accordance with the present invention

"FIG. 5B is a cross sectional schematic view of the formed in place support of FIG. 5A."

URL and more information on this patent application, see: Lashinski, Randall T.; Bishop, Gordon B. Stentless Aortic Valve Replacement with High Radial Strength. Filed September 26, 2013 and posted June 19, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=1584&p=32&f=G&l=50&d=PG01&S1=20140612.PD.&OS=PD/20140612&RS=PD/20140612

Keywords for this news article include: Surgery, Arteries, Angiology, Cardiology, Aortic Valve, Heart Valves, Cardio Device, Cardiovascular, Medical Devices, Direct Flow Medical Inc..

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Source: Politics & Government Week


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