US20100161044A1 - Devices, systems, and methods for reshaping a heart valve annulus - Google Patents

Abstract

Implants or systems of implants and methods apply a selected force vector or a selected combination of force vectors within or across the left atrium, which allow mitral valve leaflets to better coapt. The implants or systems of implants and methods make possible rapid deployment, facile endovascular delivery, and full intra-atrial retrievability. The implants or systems of implants and methods also make use of strong fluoroscopic landmarks. The implants or systems of implants and methods make use of an adjustable implant and a fixed length implant. The implants or systems of implants and methods may also utilize a bridge stop to secure the implant, and the methods of implantation employ various tools.

Description

RELATED APPLICATIONS
• This application is a divisional of co-pending application Ser. No. 11/089,940 filed 25 Mar. 2005, which is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/894,433, filed Jul. 19, 2004, and entitled “Devices, Systems, and Methods for Reshaping a Heart Valve Annulus,” which is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/677,104, filed Oct. 1, 2003, and entitled “Devices, Systems, and Methods for Reshaping a Heart Valve Annulus,” which claims the benefit of U.S. patent application Ser. No. 09/666,617, filed Sep. 20, 2000 and entitled “Heart Valve Annulus Device and Methods of Using Same,” which is incorporated herein by reference. This application also claims the benefit of Patent Cooperation Treaty Application Serial No. PCT/US02/31376, filed Oct. 1, 2002 and entitled “Systems and Devices for Heart Valve Treatments,” which claimed the benefit of U.S. Provisional Patent Application Ser. No. 60/326,590, filed Oct. 1, 2001, which are incorporated herein by reference. This application also claims the benefit of U.S. Provisional Application Ser. No. 60/429,444, filed Nov. 26, 2002, and entitled “Heart Valve Remodeling Devices;” U.S. Provisional Patent Application Ser. No. 60/429,709, filed Nov. 26, 2002, and entitled “Neo-Leaflet Medical Devices;” and U.S. Provisional Patent Application Ser. No. 60/429,462, filed Nov. 26, 2002, and entitled “Heart Valve Leaflet Retaining Devices,” which are each incorporated herein by reference.
FIELD OF THE INVENTION
• The invention is directed to devices, systems, and methods for improving the function of a heart valve, e.g., in the treatment of mitral valve regurgitation.
BACKGROUND OF THE INVENTIONI. The Anatomy of a Healthy Heart
• The heart (seeFIG. 1) is slightly larger than a clenched fist. It is a double (left and right side), self-adjusting muscular pump, the parts of which work in unison to propel blood to all parts of the body. The right side of the heart receives poorly oxygenated (“venous”) blood from the body from the superior vena cava and inferior vena cava and pumps it through the pulmonary artery to the lungs for oxygenation. The left side receives well-oxygenation (“arterial”) blood from the lungs through the pulmonary veins and pumps it into the aorta for distribution to the body.
• The heart has four chambers, two on each side—the right and left atria, and the right and left ventricles. The atriums are the blood-receiving chambers, which pump blood into the ventricles. The ventricles are the blood-discharging chambers. A wall composed of fibrous and muscular parts, called the interatrial septum separates the right and left atriums (seeFIGS. 2 to 4). The fibrous interatrial septum is, compared to the more friable muscle tissue of the heart, a more materially strong tissue structure in its own extent in the heart. An anatomic landmark on the interatrial septum is an oval, thumbprint sized depression called the oval fossa, or fossa ovalis (shown inFIGS. 4 and 6), which is a remnant of the oval foramen and its valve in the fetus. It is free of any vital structures such as valve structure, blood vessels and conduction pathways. Together with its inherent fibrous structure and surrounding fibrous ridge which makes it identifiable by angiographic techniques, the fossa ovalis is the favored site for trans-septal diagnostic and therapeutic procedures from the right into the left heart. Before birth, oxygenated blood from the placenta was directed through the oval foramen into the left atrium, and after birth the oval foramen closes.
• The synchronous pumping actions of the left and right sides of the heart constitute the cardiac cycle. The cycle begins with a period of ventricular relaxation, called ventricular diastole. The cycle ends with a period of ventricular contraction, called ventricular systole.
• The heart has four valves (seeFIGS. 2 and 3) that ensure that blood does not flow in the wrong direction during the cardiac cycle; that is, to ensure that the blood does not back flow from the ventricles into the corresponding atria, or back flow from the arteries into the corresponding ventricles. The valve between the left atrium and the left ventricle is the mitral valve. The valve between the right atrium and the right ventricle is the tricuspid valve. The pulmonary valve is at the opening of the pulmonary artery. The aortic valve is at the opening of the aorta.
• At the beginning of ventricular diastole (i.e., ventricular filling) (seeFIG. 2), the aortic and pulmonary valves are closed to prevent back flow from the arteries into the ventricles. Shortly thereafter, the tricuspid and mitral valves open (asFIG. 2 shows), to allow flow from the atriums into the corresponding ventricles. Shortly after ventricular systole (i.e., ventricular emptying) begins, the tricuspid and mitral valves close (see FIG.3)—to prevent back flow from the ventricles into the corresponding atriums—and the aortic and pulmonary valves open—to permit discharge of blood into the arteries from the corresponding ventricles.
• The opening and closing of heart valves occur primarily as a result of pressure differences. For example, the opening and closing of the mitral valve occurs as a result of the pressure differences between the left atrium and the left ventricle. During ventricular diastole, when ventricles are relaxed, the venous return of blood from the pulmonary veins into the left atrium causes the pressure in the atrium to exceed that in the ventricle. As a result, the mitral valve opens, allowing blood to enter the ventricle. As the ventricle contracts during ventricular systole, the intraventricular pressure rises above the pressure in the atrium and pushes the mitral valve shut.
• The mitral and tricuspid valves are defined by fibrous rings of collagen, each called an annulus, which forms a part of the fibrous skeleton of the heart. The annulus provides attachments for the two cusps or leaflets of the mitral valve (called the anterior and posterior cusps) and the three cusps or leaflets of the tricuspid valve. The leaflets receive chordae tendineae from more than one papillary muscle. In a healthy heart, these muscles and their tendinous chords support the mitral and tricuspid valves, allowing the leaflets to resist the high pressure developed during contractions (pumping) of the left and right ventricles.FIGS. 5 and 6 show the chordae tendineae and papillary muscles in the left ventricle that support the mitral valve.
• AsFIGS. 2 and 3 show, the anterior (A) portion of the mitral valve annulus is intimate with the non-coronary leaflet of the aortic valve. AsFIGS. 2 and 3 also show, the mitral valve annulus is also near other critical heart structures, such as the circumflex branch of the left coronary artery (which supplies the left atrium, a variable amount of the left ventricle, and in many people the SA node) and the AV node (which, with the SA node, coordinates the cardiac cycle).
• Also in the vicinity of the posterior (P) mitral valve annulus is the coronary sinus and its tributaries. These vessels drain the areas of the heart supplied by the left coronary artery. The coronary sinus and its tributaries receive approximately 85% of coronary venous blood. The coronary sinus empties into the posterior of the right atrium, anterior and inferior to the fossa ovalis (seeFIG. 4). A tributary of the coronary sinus is called the great cardiac vein, which courses parallel to the majority of the posterior mitral valve annulus, and is superior to the posterior mitral valve annulus by an average distance of about 9.64+/−3.15 millimeters (Yamanouchi, Y,Pacing and Clinical Electophysiology21(11):2522-6; 1998).
II. Characteristics and Causes of Mitral Valve Dysfunction
• When the left ventricle contracts after filling with blood from the left atrium, the walls of the ventricle move inward and release some of the tension from the papillary muscle and chords. The blood pushed up against the under-surface of the mitral leaflets causes them to rise toward the annulus plane of the mitral valve. As they progress toward the annulus, the leading edges of the anterior and posterior leaflet come together forming a seal and closing the valve. In the healthy heart, leaflet coaptation occurs near the plane of the mitral annulus. The blood continues to be pressurized in the left ventricle until it is ejected into the aorta. Contraction of the papillary muscles is simultaneous with the contraction of the ventricle and serves to keep healthy valve leaflets tightly shut at peak contraction pressures exerted by the ventricle.
• In a healthy heart (seeFIGS. 7 and 8), the dimensions of the mitral valve annulus create an anatomic shape and tension such that the leaflets coapt, forming a tight junction, at peak contraction pressures. Where the leaflets coapt at the opposing medial (CM) and lateral (CL) sides of the annulus are called the leaflet commissures.
• Valve malfunction can result from the chordae tendineae (the chords) becoming stretched, and in some cases tearing. When a chord tears, the result is a leaflet that flails. Also, a normally structured valve may not function properly because of an enlargement of or shape change in the valve annulus. This condition is referred to as a dilation of the annulus and generally results from heart muscle failure. In addition, the valve may be defective at birth or because of an acquired disease.
• Regardless of the cause (seeFIG. 9), mitral valve dysfunction can occur when the leaflets do not coapt at peak contraction pressures. AsFIG. 9 shows, the coaptation line of the two leaflets is not tight at ventricular systole. As a result, an undesired back flow of blood from the left ventricle into the left atrium can occur.
• Mitral regurgitation is a condition where, during contraction of the left ventricle, the mitral valve allows blood to flow backwards from the left ventricle into the left atrium. This has two important consequences.
• First, blood flowing back into the atrium may cause high atrial pressure and reduce the flow of blood into the left atrium from the lungs. As blood backs up into the pulmonary system, fluid leaks into the lungs and causes pulmonary edema.
• Second, the blood volume going to the atrium reduces volume of blood going forward into the aorta causing low cardiac output. Excess blood in the atrium over-fills the ventricle during each cardiac cycle and causes volume overload in the left ventricle.
• Mitral regurgitation is measured on a numeric Grade scale of 1+ to 4+ by either contrast ventriculography or by echocardiographic Doppler assessment. Grade 1+ is trivial regurgitation and has little clinical significance. Grade 2+ shows a jet of reversed flow going halfway back into the left atrium. Grade 3 regurgitation shows filling of the left atrium with reversed flow up to the pulmonary veins and a contrast injection that clears in three heart beats or less. Grade 4 regurgitation has flow reversal into the pulmonary veins and a contrast injection that does not clear from the atrium in three or fewer heart beats.
• Mitral regurgitation is categorized into two main types, (i) organic or structural and (ii) functional. Organic mitral regurgitation results from a structurally abnormal valve component that causes a valve leaflet to leak during systole. Functional mitral regurgitation results from annulus dilation due to primary congestive heart failure, which is itself generally surgically untreatable, and not due to a cause like severe irreversible ischemia or primary valvular heart disease.
• Organic mitral regurgitation is seen when a disruption of the seal occurs at the free leading edge of the leaflet due to a ruptured chord or papillary muscle making the leaflet flail; or if the leaflet tissue is redundant, the valves may prolapse the level at which coaptation occurs higher into the atrium with further prolapse opening the valve higher in the atrium during ventricular systole.
• Functional mitral regurgitation occurs as a result of dilation of heart and mitral annulus secondary to heart failure, most often as a result of coronary artery disease or idiopathic dilated cardiomyopathy. Comparing a healthy annulus inFIG. 7 to an unhealthy annulus inFIG. 9, the unhealthy annulus is dilated and, in particular, the anterior-to-posterior distance along the minor axis (line P-A) is increased. As a result, the shape and tension defined by the annulus becomes less oval (seeFIG. 7) and more round (seeFIG. 9). This condition is called dilation. When the annulus is dilated, the shape and tension conducive for coaptation at peak contraction pressures progressively deteriorate.
• The fibrous mitral annulus is attached to the anterior mitral leaflet in one-third of its circumference. The muscular mitral annulus constitutes the remainder of the mitral annulus and is attached to by the posterior mitral leaflet. The anterior fibrous mitral annulus is intimate with the central fibrous body, the two ends of which are called the fibrous trigones. Just posterior to each fibrous trigone is the commissure of which there are two, the anterior medial (CM) and the posterior lateral commissure (CL). The commissure is where the anterior leaflet meets the posterior leaflet at the annulus.
• As before described, the central fibrous body is also intimate with the non-coronary leaflet of the aortic valve. The central fibrous body is fairly resistant to elongation during the process of mitral annulus dilation. It has been shown that the great majority of mitral annulus dilation occurs in the posterior two-thirds of the annulus known as the muscular annulus. One could deduce thereby that, as the annulus dilates, the percentage that is attached to the anterior mitral leaflet diminishes.
• In functional mitral regurgitation, the dilated annulus causes the leaflets to separate at their coaptation points in all phases of the cardiac cycle. Onset of mitral regurgitation may be acute, or gradual and chronic in either organic or in functional mitral regurgitation.
• In dilated cardiomyopathy of ischemic or of idiopathic origin, the mitral annulus can dilate to the point of causing functional mitral regurgitation. It does so in approximately twenty-five percent of patients with congestive heart failure evaluated in the resting state. If subjected to exercise, echocardiography shows the incidence of functional mitral regurgitation in these patients rises to over fifty percent.
• Functional mitral regurgitation is a significantly aggravating problem for the dilated heart, as is reflected in the increased mortality of these patients compared to otherwise comparable patients without functional mitral regurgitation. One mechanism by which functional mitral regurgitation aggravates the situation in these patients is through increased volume overload imposed upon the ventricle. Due directly to the leak, there is increased work the heart is required to perform in each cardiac cycle to eject blood antegrade through the aortic valve and retrograde through the mitral valve. The latter is referred to as the regurgitant fraction of left ventricular ejection. This is added to the forward ejection fraction to yield the total ejection fraction. A normal heart has a forward ejection fraction of about 50 to 70 percent. With functional mitral regurgitation and dilated cardiomyopathy, the total ejection fraction is typically less than thirty percent. If the regurgitant fraction is half the total ejection fraction in the latter group the forward ejection fraction can be as low as fifteen percent.
III. Prior Treatment Modalities
• In the treatment of mitral valve regurgitation, diuretics and/or vasodilators can be used to help reduce the amount of blood flowing back into the left atrium. An intra-aortic balloon counterpulsation device is used if the condition is not stabilized with medications. For chronic or acute mitral valve regurgitation, surgery to repair or replace the mitral valve is often necessary.
• Currently, patient selection criteria for mitral valve surgery are very selective. Possible patient selection criteria for mitral surgery include: normal ventricular function, general good health, a predicted lifespan of greater than 3 to 5 years, NYHA Class III or IV symptoms, and at least Grade 3 regurgitation. Younger patients with less severe symptoms may be indicated for early surgery if mitral repair is anticipated. The most common surgical mitral repair procedure is for organic mitral regurgitation due to a ruptured chord on the middle scallop of the posterior leaflet.
• In conventional annuloplasty ring repair, the posterior mitral annulus is reduced along its circumference with sutures passed through a surgical annuloplasty sewing ring cuff. The goal of such a repair is to bring the posterior mitral leaflet forward toward to the anterior leaflet to better allow coaptation.
• Surgical edge-to-edge juncture repairs, which can be performed endovascularly, are also made, in which a mid valve leaflet to mid valve leaflet suture or clip is applied to keep these points of the leaflet held together throughout the cardiac cycle. Other efforts have developed an endovascular suture and a clip to grasp and bond the two mitral leaflets in the beating heart.
• Grade 3+ or 4+ organic mitral regurgitation may be repaired with such edge-to-edge technologies. This is because, in organic mitral regurgitation, the problem is not the annulus but in the central valve components.
• However, functional mitral regurgitation can persist at a high level, even after edge-to-edge repair, particularly in cases of high Grade 3+ and 4+ functional mitral regurgitation. After surgery, the repaired valve may progress to high rates of functional mitral regurgitation over time.
• In yet another emerging technology, the coronary sinus is mechanically deformed through endovascular means applied and contained to function solely within the coronary sinus.
• It is reported that twenty-five percent of the six million Americans who will have congestive heart failure will have functional mitral regurgitation to some degree. This constitutes the 1.5 million people with functional mitral regurgitation. Of these, the idiopathic dilated cardiomyopathy accounts for 600,000 people. Of the remaining 900,000 people with ischemic disease, approximately half have functional mitral regurgitation due solely to dilated annulus.
• By interrupting the cycle of progressive functional mitral regurgitation, it has been shown in surgical patients that survival is increased and in fact forward ejection fraction increases in many patients. The problem with surgical therapy is the significant insult it imposes on these chronically ill patients with high morbidity and mortality rates associated with surgical repair.
• The need remains for simple, cost-effective, and less invasive devices, systems, and methods for treating dysfunction of a heart valve, e.g., in the treatment of organic and functional mitral valve regurgitation.
SUMMARY OF THE INVENTION
• The invention comprises devices, systems, and methods for reshaping a heart valve annulus.
• One aspect of the invention provides a method of placing an implant within a heart chamber. The method can comprise deploying a guide wire in an intravascular path that extends from a first vascular access into a heart chamber and from the heart chamber to a second vascular access site different than the first vascular access site, the guide wire having a first end extending beyond the first vascular access site and a second end extending beyond the second vascular access site, coupling the implant to one end of the guide wire, and pulling on the other end of the guide wire to pull the implant along at least a portion of the intravascular path into the heart chamber.
• The method may include placing the implant in tension within the heart chamber. In one embodiment, the heart chamber can comprise the left atrium. The implant may comprise, for example, a metallic material or polymer material or a metallic wire form structure or a polymer wire form structure or suture material or equine pericardium or porcine pericardium or bovine pericardium or preserved mammalian tissue.
• An additional aspect of the invention provides a method of implanting a bridge element within a left atrium. The method may comprise, for example, deploying a guide wire in an intravascular path that extends from a first vascular access site through an interatrial septum into the left atrium and from the left atrium through a great cardiac vein to a second vascular access site that is different than the first vascular access site, the guide wire having a first end extending beyond the first vascular access site and a second end extending beyond the second vascular access site, coupling the bridge element to one end of the guide wire, pulling on the other end of the guide wire to pull the implant along at least a portion of the intravascular path into the left atrium, and placing the bridge element in tension between the great cardiac vein and the interatrial septum. The intravascular path may extend from the first vascular access site into a right atrium through a vena cava, from the right atrium through the interatrial septum into the left atrium, from the left atrium into and through a great cardiac vein into the right atrium, and from the right atrium through a vena cava to the second vascular access site. The bridge element may be coupled to the second end of the guide wire, and then the first end of the guide wire is pulled to pull the bridge element along at least a portion of the intravascular path through the great cardiac vein and into the left atrium.
• Another aspect of the invention provides a system comprising an implant sized and configured for placement within a heart chamber, a guide wire sized and configured for deployment in an intravascular path that extends from a first vascular access into the heart chamber and from the heart chamber to a second vascular access site different than the first vascular access site, the guide wire having a first end extending beyond the first vascular access site and a second end extending beyond the second vascular access site, and a connector to connect an end of the implant to one end of the guide wire such that pulling on the other end of the guide wire pulls the implant along at least a portion of the intravascular path into the heart chamber. The bridge element may comprise, for example, a metallic material or polymer material or a metallic wire form structure or a polymer wire form structure or suture material or equine pericardium or porcine pericardium or bovine pericardium or preserved mammalian tissue.
• Another aspect of the invention provides a system comprising a bridge element sized and configured to be implanted within the left atrium between the great cardiac vein and the interatrial septum, the bridge element having opposite ends, a guide wire sized and configured to be deployed in an intravascular path that extends from a first vascular access site through an interatrial septum into the left atrium and from the left atrium through a great cardiac vein to a second vascular access site that is different than the first vascular access site, the guide wire having a first end extending beyond the first vascular access site and a second end extending beyond the second vascular access site, a connector to connect an end of the bridge element to one end of the guide wire such that pulling on the other end of the guide wire pulls the bridge element along at least a portion of the intravascular path into the left atrium, a posterior bridge stop sized and configured to be secured to an end of the bridging element to abut against venous tissue within the great cardiac vein, and an anterior bridge stop sized and configured to be secured to the bridging element to abut against tissue on the interatrial septum within the right atrium.
• An additional embodiment provides a method of placing an implant within a heart chamber comprising deploying a guide wire in an intravascular path that extends from a first vascular access into a heart chamber and from the heart chamber to a second vascular access site different than the first vascular access site, the guide wire having a first end extending beyond the first vascular access site and a second end extending beyond the second vascular access site, deploying an exchange catheter in an intravascular path defined by the guide wire, the exchange catheter being deployed over the guide wire and having a first end extending beyond the first vascular access site and a second end extending beyond the second vascular access site, coupling the implant to one end of the guide wire, and pulling on the other end of the guide wire to pull the implant along at least a portion of the intravascular path through the exchange catheter and into the heart chamber. The method may further include placing the implant in tension within the heart chamber.
• Other features and advantages of the invention shall be apparent based upon the accompanying description, drawings, and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is an anatomic anterior view of a human heart, with portions broken away and in section to view the interior heart chambers and adjacent structures.
• FIG. 2 is an anatomic superior view of a section of the human heart showing the tricuspid valve in the right atrium, the mitral valve in the left atrium, and the aortic valve in between, with the tricuspid and mitral valves open and the aortic and pulmonary valves closed during ventricular diastole (ventricular filling) of the cardiac cycle.
• FIG. 3 is an anatomic superior view of a section of the human heart shown inFIG. 2, with the tricuspid and mitral valves closed and the aortic and pulmonary valves opened during ventricular systole (ventricular emptying) of the cardiac cycle.
• FIG. 4 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the interior of the heart chambers and associated structures, such as the fossa ovalis, coronary sinus, and the great cardiac vein.
• FIG. 5 is an anatomic lateral view of a human heart with portions broken away and in section to show the interior of the left ventricle and associated muscle and chord structures coupled to the mitral valve.
• FIG. 6 is an anatomic lateral view of a human heart with portions broken away and in section to show the interior of the left ventricle and left atrium and associated muscle and chord structures coupled to the mitral valve.
• FIG. 7 is a superior view of a healthy mitral valve, with the leaflets closed and coapting at peak contraction pressures during ventricular systole.
• FIG. 8 is an anatomic superior view of a section of the human heart, with the normal mitral valve shown inFIG. 7 closed during ventricular systole (ventricular emptying) of the cardiac cycle.
• FIG. 9 is a superior view of a dysfunctional mitral valve, with the leaflets failing to coapt during peak contraction pressures during ventricular systole, leading to mitral regurgitation.
• FIGS. 10A and 10B are anatomic anterior perspective views of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes an inter-atrial bridging element that spans the mitral valve annulus, with a posterior bridge stop positioned in the great cardiac vein and an anterior bridge stop, including a septal member, positioned on the inter-atrial septum, the inter-atrial bridging element extending in an essentially straight path generally from a mid-region of the annulus to the inter-atrial septum.
• FIG. 10C is an anatomic anterior perspective view of an alternative embodiment of the implant system shown inFIGS. 10A and 10B, showing an anterior bridge stop without the addition of a septal member.
• FIG. 11A is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system of the type shown inFIGS. 10A and 10B, with the anterior region of the implant extending through a pass-through structure, such as a septal member, in the inter-atrial septum and situated in the superior vena cava.
• FIG. 11B is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system of the type shown inFIGS. 10A and 10B, with the anterior region of the implant extending through a pass-through structure, such as a septal member, in the inter-atrial septum and situated in the inferior vena cava.
• FIG. 11C is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system of the type shown inFIGS. 10A to 10C, with the anterior region of the implant situated on the inter-atrial septum, as well as in the superior vena cava and the inferior vena cava.
• FIG. 12 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes an inter-atrial bridging element that spans the mitral valve annulus, with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the inter-atrial bridging element extending in an essentially straight path generally from a lateral region of the annulus.
• FIG. 13 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes an inter-atrial bridging element that spans the mitral valve annulus, with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the inter-atrial bridging element extending in an upwardly curved or domed path generally from a lateral region of the annulus.
• FIG. 14 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes an inter-atrial bridging element that spans the mitral valve annulus, with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the inter-atrial bridging element extending in a downwardly curved path generally from a lateral region of the annulus.
• FIG. 15 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes an inter-atrial bridging element that spans the mitral valve annulus, with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the inter-atrial bridging element extending in a curvilinear path, bending around a trigone of the annulus generally from a mid-region region of the annulus.
• FIG. 16 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes an inter-atrial bridging element that spans the mitral valve annulus, with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the inter-atrial bridging element extending in a curvilinear path, bending around a trigone of the annulus generally from a mid-region region of the annulus, as well as elevating in an arch toward the dome of the left atrium.
• FIG. 17 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes an inter-atrial bridging element that spans the mitral valve annulus, with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the inter-atrial bridging element extending in a curvilinear path, bending around a trigone of the annulus generally from a mid-region region of the annulus, as well as dipping downward toward the plane of the valve.
• FIG. 18 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes two inter-atrial bridging elements that span the mitral valve annulus, each with a posterior bridge stop in the great cardiac vein and an anterior bridge stop on the inter-atrial septum, the inter-atrial bridging elements both extending in generally straight paths from different regions of the annulus.
• FIG. 19 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes two inter-atrial bridging elements that span the mitral valve annulus, each with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the inter-atrial bridging elements both extending in generally curvilinear paths from adjacent regions of the annulus.
• FIG. 20 is an anatomic anterior perspective view of the left and right atriums, with portions broken away and in section to show the presence of an implant system that includes three inter-atrial bridging elements that span the mitral valve annulus, each with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, two of the inter-atrial bridging elements extending in generally straight paths from different regions of the annulus, and the third inter-atrial bridging elements extending in a generally curvilinear path toward a trigone of the annulus.
• FIG. 21A is a side view of a septal member which may be used as part of the implant system of the type shown inFIGS. 10A and 10B.
• FIG. 21B is a side view of a deployed septal member of the type shown inFIG. 21A, showing the member sandwiching portions of the septum through an existing hole.
• FIGS. 22A and 22B are sectional views showing the ability of a bridge stop used in conjunction with the implant shown inFIGS. 10A to 10C to move back and forth independent of the septal wall and inner wall of the great cardiac vein.
• FIGS. 23 to 30 are anatomic views depicting representative catheter-based devices and steps for implanting an implant system of the type shown inFIGS. 10A to 10C.
• FIG. 31 is an anatomic section view of the left atrium and associated mitral valve structure, showing mitral dysfunction.
• FIG. 32 is an anatomic superior view of a section of the human heart, showing the presence of an implant system of the type shown inFIGS. 10A and 10B.
• FIG. 33 is an anatomic section view of the implant system taken generally along line33-33 inFIG. 32, showing the presence of an implant system of the type shown inFIGS. 10A and 10B, and showing proper coaptation of the mitral valve leaflets.
• FIGS. 34A to 34D are sectional views of a crimp tube for connecting a guide wire to a bridging element, and showing the variations in the crimps used.
• FIG. 35A is an anatomic partial view of a patient depicting access points used for implantation of an implant system, and also showing a loop guide wire accessible to the exterior the body at two locations.
• FIG. 35B is an anatomic view depicting a representative alternative catheter-based device for implanting an implant system of the type shown inFIGS. 10A to 10C, and showing a bridging element being pulled through the vasculature structure by a loop guide wire.
• FIG. 36A is an anatomic partial view of a patient showing a bridge stop connected to a bridging element in preparation to be pulled and/or pushed through the vasculature structure and positioned within the great cardiac vein.
• FIG. 36B is an anatomic view depicting a representative alternative catheter-based device for implanting a system of the type shown inFIGS. 10A to 10C, and showing a bridge stop being positioned within the great cardiac vein.
• FIG. 37A is a perspective view of a catheter used in the implantation of an implant system of the type shown inFIGS. 10A to 10C.
• FIG. 37B is a partial sectional view showing a magnetic head of the catheter as shown inFIG. 37A.
• FIG. 38 is a perspective view of an additional catheter which may be used in the implantation of an implant system of the type shown inFIGS. 10A to 10C.
• FIG. 39 is a partial perspective view of the interaction between the magnetic head of the catheter shown inFIG. 37A and the magnetic head of the catheter shown inFIG. 38, showing a guide wire extending out of one magnetic head and into the other magnetic head.
• FIG. 40 is an anatomic partial perspective view of the magnetic catheter heads shown inFIG. 39, with one catheter shown in the left atrium and one catheter shown in the great cardiac vein.
• FIG. 41 is a perspective view of an additional catheter which may be used in the implantation of an implant system of the type shown inFIGS. 10A to 10C.
• FIGS. 42A to 42C are partial perspective views of catheter tips which may be used with the catheter shown inFIG. 41.
• FIG. 43A is a perspective view of a symmetrically shaped T-shaped bridge stop or member which may be used with the implant system of the type shown inFIGS. 10A to 10C.
• FIG. 43B is a perspective view of an alternative embodiment of the T-shaped bridge stop shown inFIG. 43A, showing the bridge stop being asymmetric and having one limb shorter than the other.
• FIG. 44A is an exploded view of a bridge stop and associated driver which may be used with the implant system of the type shown inFIGS. 10A to 10C.
• FIG. 44B is a bottom view of the bridge stop shown inFIG. 44A.
• FIG. 44C is a top view of a screw used in the bridge stop of the type shown inFIG. 44A.
• FIG. 45A is an anatomic partial perspective view of alternative magnetic catheter heads, with one catheter shown in the left atrium and one catheter shown in the great cardiac vein, and showing a side to end configuration.
• FIG. 45B is a partial sectional view of the alternative magnetic catheter heads of the type shown inFIG. 45A, showing a guide wire piercing the wall of the great cardiac vein and left atrium and extending into the receiving catheter.
• FIG. 45C is a partial perspective view of an alternative magnetic head of the type shown inFIG. 45B.
• FIG. 46 is an anatomic partial perspective view of an additional alternative embodiment for the magnetic catheter heads of the type shown inFIG. 45A, showing a side to side configuration.
• FIGS. 47A to 51 are perspective and sectional views of alternative embodiments of a bridge stop of the type shown inFIG. 44A.
• FIG. 52A is a perspective view of an alternative embodiment of a T-shaped bridge stop or member of the type shown inFIG. 43A, showing a balloon expandable or self-expanding stent with a reinforcing strut.
• FIG. 52B is a perspective view of an alternative embodiment of a T-shaped bridge stop or member of the type shown inFIG. 52A, showing the expandable or self-expanding stent in a lattice or half stent configuration.
• FIGS. 53A to 53F are perspective views showing alternative methods of connecting a bridging element to a bridge stop or T-shaped member.
• FIGS. 54 to 56A are perspective views of alternative implant systems of the type shown inFIGS. 10A to 10C, showing alternative bridge locks in both the anterior bridge stop region and the posterior bridge stop region.
• FIG. 56B is a side view of an alternative bridge stop of the type shown inFIG. 56A.
• FIGS. 57 to 59 are perspective views of additional alternative bridge locks.
• FIG. 60A is a perspective view of an alternative bridge stop and showing the deployment catheter and deployment wire.
• FIG. 60B is a side view of the alternative bridge stop of the type shown inFIG. 60A, showing the bridge stop in the deployment catheter prior to being deployed.
• FIG. 61A is a perspective view of an alternative bridge stop including a single layer of pericardium.
• FIG. 61B is a side view of the alternative bridge stop of the type shown inFIG. 61A, showing the bridge stop in the deployment catheter prior to being deployed.
• FIG. 62A is a perspective view of an alternative bridge stop including multiple layers of pericardium.
• FIG. 62B is a side view of the alternative bridge stop of the type shown inFIG. 62A, showing the bridge stop in the deployment catheter prior to being deployed.
• FIG. 63A is a perspective view of an alternative bridge stop including a balloon structure.
• FIG. 63B is a side view of the alternative bridge stop of the type shown inFIG. 63A, showing the bridge stop in the deployment catheter prior to being deployed.
• FIG. 63C is a side view of the alternative bridge stop of the type shown inFIG. 63A, showing the bridge stop just after exiting the deployment catheter and prior to being deployed.
• FIG. 64 is an anatomic anterior perspective view of the left atrium and a portion of the right atrium, with portions broken away and in section to show the presence of an alternative implant system of the type shown inFIGS. 10A to 10C, the alternative implant system includes a fixed length inter-atrial bridging element that spans the mitral valve annulus, with a posterior bridge stop positioned in the great cardiac vein and an anterior bridge stop positioned on the inter-atrial septum, the inter-atrial bridging element extending in an essentially straight path generally from a mid-region of the annulus to the inter-atrial septum.
• FIG. 65 is an anatomic anterior perspective view of the left atrium, and a portion of the right atrium, with portions broken away and in section to show the presence of an alternative implant system of the type shown inFIG. 64, the alternative implant system includes a fixed length inter-atrial bridging element that spans the mitral valve annulus, with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the fixed length inter-atrial bridging element extending in a curvilinear path, bending around a trigone of the annulus generally from a mid-region region of the annulus, as well as dipping downward toward the plane of the valve.
• FIG. 66 is an anatomic anterior perspective view of the left atrium, and a portion of the right atrium, with portions broken away and in section to show the presence of an alternative implant system of the type shown inFIG. 64, the alternative implant system includes a fixed length inter-atrial bridging element that spans the mitral valve annulus, with a posterior region situated in the great cardiac vein and an anterior region situated on the interatrial septum, the fixed length inter-atrial bridging element extending in a curvilinear path, bending around a trigone of the annulus generally from a mid-region region of the annulus, as well as elevating in an arch toward the dome of the left atrium.
• FIG. 67 is a side view of a fixed length inter-atrial bridging element of the type shown inFIG. 64, and showing the fixed length bridging element with a connective head on a first end and a stop on a second end.
• FIG. 68 is a side view of an arched or non-linear fixed length inter-atrial bridging element of the type shown inFIGS. 65 and 66, and showing the arched fixed length bridging element with a connective head on a first end and a stop on a second end.
• FIG. 69 is a perspective view of the arched fixed length inter-atrial bridging element of the type shown inFIG. 68, and showing and showing an alternative embodiment for a bridge stop on a second end.
• FIGS. 70A and 70B are perspective views showing the connective head of the fixed length bridging element guided by the tracking rail into the receiving aperture in a posterior or anterior bridge stop structure.
• FIGS. 71A and 71B are sectional views showing the ability of a bridge stop used in conjunction with the implant shown inFIG. 64 to move back and forth independent of the septal wall and inner wall of the great cardiac vein.
• FIG. 72 is an anatomic anterior perspective view of the left atrium and a portion of the right atrium, with portions broken away and in section to show a step of implanting the implant system including the fixed length inter-atrial bridging element of the type shown inFIG. 64.
• FIG. 73 is an anatomic anterior perspective view of the left atrium and a portion of the right atrium, with portions broken away and in section to show a step of implanting the implant system including the arched fixed length inter-atrial bridging element of the type shown inFIGS. 65 and 66.
DESCRIPTION OF THE PREFERRED EMBODIMENT
• Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
I. Trans-Septal Implants for Direct Shortening of the Minor Axis of a Heart Valve Annulus
• A. Implant Structure
• FIGS. 10A to 10C show embodiments of animplant10 that is sized and configured to extend across the left atrium in generally an anterior-to-posterior direction, spanning the mitral valve annulus. Theimplant10 comprises a spanning region or bridgingelement12 having a posteriorbridge stop region14 and an anteriorbridge stop region16.
• The posteriorbridge stop region14 is sized and configured to allow thebridging element12 to be placed in a region of atrial tissue above the posterior mitral valve annulus. This region is preferred, because it generally presents more tissue mass for obtaining purchase of the posteriorbridge stop region14 than in a tissue region at or adjacent to the posterior mitral annulus. Engagement of tissue at this supra-annular location also may reduce risk of injury to the circumflex coronary artery. In a small percentage of cases, the circumflex coronary artery may pass over and medial to the great cardiac vein on the left atrial aspect of the great cardiac vein, coming to lie between the great cardiac vein and endocardium of the left atrium. However, since the forces in the posterior bridge stop region are directed upward and inward relative to the left atrium and not in a constricting manner along the long axis of the great cardiac vein, the likelihood of circumflex artery compression is less compared to other technologies in this field that do constrict the tissue of the great cardiac vein. Nevertheless, should a coronary angiography reveal circumflex artery stenosis, the symmetrically shaped posterior bridge stop may be replaced by an asymmetrically shaped bridge stop, such as where one limb of a T-shaped member is shorter than the other, thus avoiding compression of the crossing point of the circumflex artery. The asymmetric form may also be selected first based on a pre-placement angiogram.
• An asymmetric posterior bridge stop may be utilized for other reasons as well. The asymmetric posterior bridge stop may be selected where a patient is found to have a severely stenotic distal great cardiac vein, where the asymmetric bridge stop better serves to avoid obstruction of that vessel. In addition, an asymmetric bridge stop may be chosen for its use in selecting application of forces differentially and preferentially on different points along the posterior mitral annulus to optimize treatment, i.e., in cases of malformed or asymmetrical mitral valves.
• The anteriorbridge stop region16 is sized and configured to allow thebridging element12 to be placed, upon passing into the right atrium through the septum, adjacent tissue in or near the right atrium. For example, as is shown inFIGS. 10A to 10C, the anteriorbridge stop region16 may be adjacent or abutting a region of fibrous tissue in the interatrial septum. As shown, thebridge stop site16 is desirably superior to the anterior mitral annulus at about the same elevation or higher than the elevation of the posteriorbridge stop region14. In the illustrated embodiment, the anteriorbridge stop region16 is adjacent to or near the inferior rim of the fossa ovalis. Alternatively, the anteriorbridge stop region16 can be located at a more superior position in the septum, e.g., at or near the superior rim of the fossa ovalis. The anteriorbridge stop region16 can also be located in a more superior or inferior position in the septum, away from the fossa ovalis, provided that the bridge stop site does not harm the tissue region.
• Alternatively, as can be seen inFIGS. 11A and 11B, the anteriorbridge stop region16, upon passing through the septum into the right atrium, may be positioned within or otherwise situated in the superior vena cava (SVC) or the inferior vena cava (IVC), instead of at the septum itself.
• In use, the spanning region or bridgingelement12 can be placed into tension between the twobridge stop regions14 and16. Theimplant10 thereby serves to apply a direct mechanical force generally in a posterior to anterior direction across the left atrium. The direct mechanical force can serve to shorten the minor axis (line P-A inFIG. 7) of the annulus. In doing so, theimplant10 can also reactively reshape the annulus along its major axis (line CM-CL inFIG. 7) and/or reactively reshape other surrounding anatomic structures. It should be appreciated, however, the presence of theimplant10 can serve to stabilize tissue adjacent the heart valve annulus, without affecting the length of the minor or major axes.
• It should also be appreciated that, when situated in other valve structures, the axes affected may not be the “major” and “minor” axes, due to the surrounding anatomy. In addition, in order to be therapeutic, theimplant10 may only need to reshape the annulus during a portion of the heart cycle, such as during late diastole and early systole when the heart is most full of blood at the onset of ventricular systolic contraction, when most of the mitral valve leakage occurs. For example, theimplant10 may be sized to restrict outward displacement of the annulus during late ventricular diastolic relaxation as the annulus dilates.
• The mechanical force applied by theimplant10 across the left atrium can restore to the heart valve annulus and leaflets a more normal anatomic shape and tension. The more normal anatomic shape and tension are conducive to coaptation of the leaflets during late ventricular diastole and early ventricular systole, which, in turn, reduces mitral regurgitation.
• In its most basic form, theimplant10 is made from a biocompatible metallic or polymer material, or a metallic or polymer material that is suitably coated, impregnated, or otherwise treated with a material to impart biocompatibility, or a combination of such materials. The material is also desirably radio-opaque or incorporates radio-opaque features to facilitate fluoroscopic visualization.
• Theimplant10 can be formed by bending, shaping, joining, machining, molding, or extrusion of a metallic or polymer wire form structure, which can have flexible or rigid, or inelastic or elastic mechanical properties, or combinations thereof. Alternatively, theimplant10 can be formed from metallic or polymer thread-like or suture material. Materials from which the implant can be formed include, but are not limited to, stainless steel, Nitinol, titanium, silicone, plated metals, Elgiloy™, NP55, and NP57.
• Theimplant10 can take various shapes and have various cross-sectional geometries. Theimplant10 can have, e.g., a generally curvilinear (i.e., round or oval) cross-section, or a generally rectilinear cross section (i.e., square or rectangular), or combinations thereof. Shapes that promote laminar flow and therefore reduce hemolysis are contemplated, with features such as smoother surfaces and longer and narrower leading and trailing edges in the direction of blood flow.
• B. The Posterior Bridge Stop Region
• The posteriorbridge stop region14 is sized and configured to be located within or at the left atrium at a supra-annular position, i.e., positioned within or near the left atrium wall above the posterior mitral annulus.
• In the illustrated embodiment, the posteriorbridge stop region14 is shown to be located generally at the level of the great cardiac vein, which travels adjacent to and parallel to the majority of the posterior mitral valve annulus. This tributary of the coronary sinus can provide a strong and reliable fluoroscopic landmark when a radio-opaque device is placed within it or contrast dye is injected into it. As previously described, securing the bridgingelement12 at this supra-annular location also lessens the risk of encroachment of and risk of injury to the circumflex coronary artery compared to procedures applied to the mitral annulus directly. Furthermore, the supra-annular position assures no contact with the valve leaflets therefore allowing for coaptation and reduces the risk of mechanical damage.
• The great cardiac vein also provides a site where relatively thin, non-fibrous atrial tissue can be readily augmented and consolidated. To enhance hold or purchase of the posteriorbridge stop region14 in what is essentially non-fibrous heart tissue, and to improve distribution of the forces applied by theimplant10, the posteriorbridge stop region14 may include aposterior bridge stop18 placed within the great cardiac vein and abutting venous tissue. This makes possible the securing of the posteriorbridge stop region14 in a non-fibrous portion of the heart in a manner that can nevertheless sustain appreciable hold or purchase on that tissue for a substantial period of time, without dehiscence, expressed in a clinically relevant timeframe.
• C. The Anterior Bridge Stop Region
• The anteriorbridge stop region16 is sized and configured to allow thebridging element12 to remain firmly in position adjacent or near the fibrous tissue and the surrounding tissues in the right atrium side of the atrial septum. The fibrous tissue in this region provides superior mechanical strength and integrity compared with muscle and can better resist a device pulling through. The septum is the most fibrous tissue structure in its own extent in the heart. Surgically handled, it is usually one of the only heart tissues into which sutures actually can be placed and can be expected to hold without pledgets or deep grasps into muscle tissue, where the latter are required.
• AsFIGS. 10A to 10C show, the anteriorbridge stop region16 passes through the septal wall at a supra-annular location above the plane of the anterior mitral valve annulus. The supra-annular distance on the anterior side can be generally at or above the supra-annular distance on the posterior side. As before pointed out, the anteriorbridge stop region16 is shown inFIGS. 10A to 10C at or near the inferior rim of the fossa ovalis, although other more inferior or more superior sites can be used within or outside the fossa ovalis, taking into account the need to prevent harm to the septal tissue and surrounding structures.
• By locating the bridgingelement12 at this supra-annular level within the right atrium, which is fully outside the left atrium and spaced well above the anterior mitral annulus, theimplant10 avoids the impracticalities of endovascular attachment at or adjacent to the anterior mitral annulus, where there is just a very thin rim of annulus tissue that is bounded anteriorly by the anterior leaflet, inferiorly by the aortic outflow tract, and medially by the atrioventricular node of the conduction system. The anterior mitral annulus is where the non-coronary leaflet of the aortic valve attaches to the mitral annulus through the central fibrous body. Anterior location of theimplant10 in the supra-annular level within the right atrium (either in the septum or in a vena cava) avoids encroachment of and risk of injury to both the aortic valve and the AV node.
• The purchase of the anteriorbridge stop region16 in fibrous septal tissue is desirably enhanced by aseptal member30 or ananterior bridge stop20, or a combination of both.FIGS. 10A and 10B show the anterior bridge stop region including aseptal member30.FIG. 10C shows the anterior bridge stop region without a septal member. Theseptal member30 may be an expandable device and also may be a commercially available device such as a septal occluder, e.g., Amplatzer® PFO Occluder (seeFIGS. 21A and 21B). Theseptal member30 preferably mechanically amplifies the hold or purchase of the anteriorbridge stop region16 in the fibrous tissue site. Theseptal member30 also desirably increases reliance, at least partly, on neighboring anatomic structures of the septum to make firm the position of theimplant10. In addition, theseptal member30 may also serve to plug or occlude the small aperture that was created in the fossa ovalis or surrounding area during the implantation procedure.
• Anticipating that pinpoint pulling forces will be applied by the anteriorbridge stop region16 to the septum, the forces acting on theseptal member30 should be spread over a moderate area, without causing impingement on valve, vessels or conduction tissues. With the pulling or tensioning forces being transmitted down to the annulus, shortening of the minor axis is achieved. A flexurally stiff septal member is preferred because it will tend to cause less focal narrowing in the direction of bridge element tension of the left atrium as tension on the bridging element is increased. The septal member should also have a low profile configuration and highly washable surfaces to diminish thrombus formation for devices deployed inside the heart. The septal member may also have a collapsed configuration and a deployed configuration. Theseptal member30 may also include a hub31 (seeFIGS. 21A and 21B) to allow attachment of thebridge stop20. A septal brace may also be used in combination with theseptal member30 andanterior bridge stop20 to distribute forces uniformly along the septum (seeFIG. 11C). Alternatively, devices inl the IVC or the SVC can be used as bridge stop sites (seeFIGS. 11A and 11B), instead of confined to the septum.
• Location of the posterior and anteriorbridge stop regions14 and16 having radio-opaque bridge locks and well demarcated fluoroscopic landmarks respectively at the supra-annular tissue sites just described, not only provides freedom from key vital structure damage or local impingement—e.g., to the circumflex artery, AV node, and the left coronary and non-coronary cusps of the aortic valve—but the supra-annular focused sites are also not reliant on purchase between tissue and direct tension-loaded penetrating/biting/holding tissue attachment mechanisms. Instead, physical structures and force distribution mechanisms such as stents, T-shaped members, and septal members can be used, which better accommodate the attachment or abutment of mechanical levers and bridge locks, and through which potential tissue tearing forces can be better distributed. Further, thebridge stop sites14,16 do not require the operator to use complex imaging. Adjustment of implant position after or during implantation is also facilitated, free of these constraints. Thebridge stop sites14,16 also make possible full intra-atrial retrieval of theimplant10 by endovascularly snaring and then cutting the bridgingelement12 at either side of the left atrial wall, from which it emerges.
• D. Orientation of the Bridging Element
• In the embodiments shown inFIGS. 10A to 10C, theimplant10 is shown to span the left atrium beginning at a posterior point of focus superior to the approximate mid-point of the mitral valve annulus, and proceeding in an anterior direction in a generally straight path directly to the region of anterior focus in the septum. As shown inFIGS. 10A to 10C, the spanning region or bridgingelement12 of theimplant10 may be preformed or otherwise configured to extend in this essentially straight path above the plane of the valve, without significant deviation in elevation toward or away from the plane of the annulus, other than as dictated by any difference in elevation between the posterior and anterior regions of placement.
• Lateral or medial deviations and/or superior or inferior deviations in this path can be imparted, if desired, to affect the nature and direction of the force vector or vectors that theimplant10 applies. It should be appreciated that the spanning region or bridgingelement12 can be preformed or otherwise configured with various medial/lateral and/or inferior/superior deviations to achieve targeted annulus and/or atrial structure remodeling, which takes into account the particular therapeutic needs and morphology of the patient. In addition, deviations in the path of the bridging element may also be imparted in order to avoid the high velocity blood path within a heart chamber, such as the left atrium.
• For example, as shown inFIG. 12, the implant is shown to span the left atrium beginning at a posterior region that is closer to a lateral trigone of the annulus (i.e., farther from the septum). Alternatively, the posterior region can be at a position that is closer to a medial trigone of the annulus (i.e., closer to the septum). From either one of these posterior regions, theimplant10 can extend in an anterior direction in a straight path directly to the anterior region in the septum. As shown inFIG. 12, likeFIG. 10A, the spanning region or bridgingelement12 of theimplant10 is preformed or otherwise configured to extend in an essentially straight path above the plane of the valve, without significant deviation in elevation toward or away from the plane of the annulus, other than as dictated by the difference in elevation, if any, between the posterior and anterior regions.
• Regardless of the particular location of the posterior region (seeFIG. 13), the spanning region or bridgingelement12 of theimplant10 can be preformed or otherwise configured to arch upward above the plane of the valve toward the dome of the left atrium Alternatively (seeFIG. 14), the spanning region or bridgingelement12 of theimplant10 can be preformed or otherwise configured to dip downward toward the plane of the valve toward the annulus, extending close to the plane of the valve, but otherwise avoiding interference with the valve leaflets. Or, still alternatively (seeFIG. 15), the spanning region or bridgingelement12 of theimplant10 can be preformed or otherwise configured to follow a curvilinear path, bending towards a trigone (medial or lateral) of the annulus before passage to the anterior region.
• Various combinations of lateral/medial deviations and superior/inferior deviations of the spanning region or bridgingelement12 of theimplant10 are of course possible. For example, as shown inFIG. 16, the spanning region or bridgingelement12 can follow a curvilinear path bending around a trigone (medial or lateral) of the annulus as well as elevate in an arch away from the plane of the valve. Or, as shown inFIG. 17, the spanning region or bridgingelement12 can follow a curvilinear path bending around a trigone (medial or lateral) of the annulus as well as dip toward the plane of the valve.
• Regardless of the orientation, more than oneimplant10 can be installed to form animplant system22. For example,FIG. 18 shows asystem22 comprising alateral implant10L and amedial implant10M of a type consistent with theimplant10 as described.FIG. 18 shows theimplants10L and10M being located at a common anteriorbridge stop region16. It should be appreciated that theimplants10L and10M can also include spaced apart anterior bridge stop regions.
• One or both of theimplants10L and10M can be straight (as inFIG. 12), or arch upward (as inFIG. 13), or bend downward (as inFIG. 14). A givensystem10 can comprise lateral andmedial implants10L and10M of different configurations. Also, a givensystem22 can comprise more than twoimplants10.
• FIG. 19 shows asystem22 comprising twocurvilinear implants10L and10M of the type shown inFIG. 15. InFIG. 19, thecurvilinear implants10L and10M are shown to be situated at a common posterior region, but theimplants10 can proceed from spaced apart posterior regions, as well. One or both of thecurvilinear implants10L and10M can be parallel with respect to the plane of the valve (as inFIG. 15), or arch upward (as inFIG. 16), or bend downward (as in FIG.17). A givensystem22 can comprisecurvilinear implants10L and10M of different configurations.
• FIG. 20 shows asystem22 comprising a directmiddle implant10D, a medialcurvilinear implant10M, and a directlateral implant10L. One, two, or all of theimplants10 can be parallel to the valve, or arch upward, or bend downward, as previously described.
• E. Posterior and Anterior Bridge Stop
• It is to be appreciated that a bridge stop as described herein, including a posterior or anterior bridge stop, describes an apparatus that may releasibly hold the bridgingelement12 in a tensioned state. As can be seen inFIGS. 22A and 22B, bridge stops20 and18 respectively are shown releasibly secured to the bridgingelement12, allowing the bridge stop structure to move back and forth independent of the inter-atrial septum and inner wall of the great cardiac vein during a portion of the cardiac cycle when the tension force may be reduced or becomes zero. Alternative embodiments are also described, all of which may provide this function. It is also to be appreciated that the general descriptions of posterior and anterior are non-limiting to the bridge stop function, i.e., a posterior bridge stop may be used anterior, and an anterior bridge stop may be used posterior.
• When the bridge stop is in an abutting relationship to a septal member or a T-shaped member, for example, the bridge stop allows the bridging element to move freely within or around the septal member or T-shaped member, i.e., the bridging element is not connected to the septal member or T-shaped member. In this configuration, the bridging element is held in tension by the bridge stop, whereby the septal member or T-shaped member serves to distribute the force applied by the bridging element across a larger surface area. Alternatively, the bridge stop may be mechanically connected to the septal member or T-shaped member, e.g., when the bridge stop is positioned over and secured to the septal member hub. In this configuration, the bridging element is fixed relative to the septal member position and is not free to move about the septal member.
II. General Methods of Trans-Septal Implantation
• Theimplants10 orimplant systems22 as just described lend themselves to implantation in a heart valve annulus in various ways. Theimplants10 orimplant systems22 can be implanted, e.g., in an open heart surgical procedure. Alternatively, theimplants10 orimplant systems22 can be implanted using catheter-based technology via a peripheral venous access site, such as in the femoral or jugular vein (via the IVC or SVC) under image guidance, or trans-arterial retrograde approaches to the left atrium through the aorta from the femoral artery also under image guidance.
• Alternatively, theimplants10 orimplant systems22 can be implanted using thoracoscopic means through the chest, or by means of other surgical access through the right atrium, also under image guidance. Image guidance includes but is not limited to fluoroscopy, ultrasound, magnetic resonance, computed tomography, or combinations thereof.
• Theimplants10 orimplant systems22 may comprise independent components that are assembled within the body to form an implant, or alternatively, independent components that are assembled exterior the body and implanted as a whole.
• FIGS. 23 to 30 show a representative embodiment of the deployment of animplant10 of the type shown inFIGS. 10A to 10C by a percutaneous, catheter-based procedure, under image guidance.
• Percutaneous vascular access is achieved by conventional methods into the femoral or jugular vein, or a combination of both. AsFIGS. 23 and 24 show, under image guidance, a first catheter, or greatcardiac vein catheter40, and a second catheter, or leftatrium catheter60, are steered through the vasculature into the right atrium. It is a function of the great cardiac vein (GCV)catheter40 and left atrium (LA)catheter60 to establish the posterior bridge end stop region. Catheter access to the right and left atriums can be achieved through either a femoral vein to IVC or SVC route (in the latter case, for a caval brace) or an upper extremity or neck vein to SVC or IVC route (in the latter case, for a caval brace). In the case of the SVC, the easiest access is from the upper extremity or neck venous system; however, the IVC can also be accessed by passing through the SVC and right atrium. Similarly the easiest access to the IVC is through the femoral vein; however the SVC can also be accessed by passing through the IVC and right atrium.FIGS. 23,24,27,28 and29 show access through both a SVC route and an IVC route for purposes of illustration.
• The implantation of theimplant10 orimplant systems22 are first described here in four general steps. Each of these steps, and the various tools used, is then described with additional detail below in section III. Additionally, alternative implantation steps may be used and are described in section IV. Additional alternative embodiments of a bridge stop are described in section V, additional alternative embodiments of a T-shaped member or bridge stop are described in section VI, and additional alternative embodiments of an anterior bridge stop are described in section VII.
• A first implantation step can be generally described as establishing the posteriorbridge stop region14. As can be seen inFIG. 24, theGCV catheter40 is steered through the vasculature into the right atrium. TheGCV catheter40 is then steered through the coronary sinus and into the great cardiac vein. The second catheter, orLA catheter60, is also steered through the vasculature and into the right atrium. TheLA catheter60 then passes through the septal wall at or near the fossa ovalis and enters the left atrium. AMullins™ catheter26 may be provided to assist the guidance of theLA catheter60 into the left atrium. Once theGCV catheter40 and theLA catheter60 are in their respective positions in the great cardiac vein and left atrium, it is a function of the GCV andLA catheters40,60 to configure the posteriorbridge stop region14.
• A second step can be generally described as establishing the trans-septal bridging element12. Adeployment catheter24 via theLA catheter60 is used to position aposterior bridge stop18 and a preferably preattached and predetermined length of bridgingelement12 within the great cardiac vein (seeFIG. 27). The predetermined length of bridgingelement12, e.g., two meters, extends from theposterior bridge stop18, through the left atrium, through the fossa ovalis, through the vasculature, and preferably remains accessible exterior the body. The predetermined length of bridging element may be cut or detached in a future step, leaving implanted the portion extending from theposterior bridge stop18 to theanterior bridge stop20. Alternatively, the bridgingelement20 may not be cut or detached at theanterior bridge stop20, but instead the bridgingelement20 may be allowed to extend into the IVC for possible future retrieval.
• A third step can be generally described as establishing the anterior bridge stop region16 (seeFIG. 29). The bridgingelement12 is first threaded through theseptal member30. Theseptal member30 is then advanced over the bridgingelement12 in a collapsed condition throughMullins catheter26, and is positioned and deployed at or near the fossa ovalis within the right atrium. Abridge stop20 may be attached to the bridgingelement12 and advanced with theseptal member30, or alternatively, thebridge stop20 may be advanced to the right atrium side of theseptal member30 after the septal member has been positioned or deployed.
• A fourth step can be generally described as adjusting the bridgingelement12 for proper therapeutic effects. With the posteriorbridge stop region14, bridgingelement12, and anteriorbridge stop region16 configured as previously described, a tension is placed on the bridgingelement12. Theimplant10 and associated regions may be allowed to settle for a predetermined amount of time, e.g., five or more seconds. The mitral valve and mitral valve regurgitation are observed for desired therapeutic effects. The tension on the bridgingelement12 may be adjusted until a desired result is achieved. Thebridge stop20 is then allowed to secure the bridgingelement12 when the desired tension or measured length or degree of mitral regurgitation reduction is achieved.
III. Detailed Methods and Implantation Apparatus
• The four generally described steps of implantation will now be described in greater detail, including the various tools and apparatus used in the implantation of theimplant10 orimplant systems22. An exemplary embodiment will describe the methods and tools for implanting animplant10. These same or similar methods and tools may be used to implant animplant system22 as well.
• A. Establish Posterior Bridge Stop Region
• 1. Implantation Tools
• Various tools may be used to establish the posteriorbridge stop region14. For example, the great cardiac vein (GCV)catheter40, the left atrium (LA)catheter60, and a cuttingcatheter80 may be used.
• FIG. 37A shows one embodiment of theGCV catheter40 in accordance with the present invention. TheGCV catheter40 preferably includes a magnetic orferromagnetic head42 positioned on the distal end of thecatheter shaft45, and ahub46 positioned on the proximal end. Thecatheter shaft45 may include afirst section48 and asecond section50. Thefirst section48 may be generally stiff to allow for torquability of theshaft45, and may be of a solid or braided construction. Thefirst section48 includes a predetermined length, e.g., fifty centimeters, to allow positioning of theshaft45 within the vasculature structure. Thesecond section50 may be generally flexible to allow for steerability within the vasculature, i.e., into the coronary sinus. Thesecond section50 may also include a predetermined length, e.g., ten centimeters. The inner diameter orlumen52 of thecatheter shaft45 is preferably sized to allow passage of aGCV guide wire54, and additionally an LA guide wire74 (seeFIGS. 39 and 40). Both theGCV guide wire54 and theLA guide wire74 may be pre-bent, and both may be steerable. TheGCV catheter40 preferably includes a radio-opaque marker56 to facilitate adjusting the catheter under image guidance to align with theLA catheter60.
• The magnetic orferromagnetic head42 is preferably polarized to magnetically attract or couple the distal end of the LA catheter60 (seeFIGS. 37B and 25). Thehead42 includes aside hole58 formed therein to allow for passage of theLA guide wire74. As shown inFIG. 40, the leftatrial side43 of thehead42 has an attracting magnetic force, and the exterior of theheart side44 of thehead42 has a repelling magnetic force. It should be appreciated that these magnetic forces may be reversed, as long as the magnetic forces in each catheter coincide with proper magnetic attraction. Themagnetic head42 preferably includes a bullet or coned shapedtip55 to allow the catheter to track into the vasculature system. Within thetip55 is anend hole59, configured to allow for passage of theGCV guide wire54.
• FIG. 38 shows one embodiment of theLA catheter60. Similar to theGCV catheter40, theLA catheter60 preferably includes a magnetic orferromagnetic head62 positioned on the distal end of thecatheter shaft65 and ahub66 positioned on the proximal end. Thecatheter shaft65 may include afirst section68 and asecond section70. Thefirst section68 may be generally stiff to allow for torquability of theshaft65, and may be of a solid or braided construction. Thefirst section68 includes a predetermined length, e.g., ninety centimeters, to allow positioning of theshaft65 within the vasculature structure. Thesecond section70 may be generally flexible and anatomically shaped to allow for steerability through the fossa ovalis and into the left atrium. Thesecond section70 may also include a predetermined length, e.g., ten centimeters. The inner diameter orlumen72 of thecatheter shaft65 is preferably sized to allow passage of anLA guide wire74, and additionally may accept theguide wire54 passed from the GCV. TheLA catheter60 may include a radio-opaque marker76 to facilitate adjusting thecatheter60 under image guidance to align with theGCV catheter40.
• The magnetic orferromagnetic head62 of theLA catheter60 is polarized to magnetically attract or couple the distal end of theGCV catheter40. As shown inFIG. 40,end side64 of thehead62 is polarized to attract theGCV catheter head42. The magnetic forces in thehead62 may be reversed, as long as attracting magnetic poles in theLA catheter60 and theGCV catheter40 are aligned. Themagnetic head62 preferably includes a generallyplanar tip75, and also includes a center bore78 sized for passage of the cuttingcatheter80 and the LA guide wire74 (seeFIG. 38).
• FIG. 41 shows the cuttingcatheter80 preferably sized to be positioned within the inner diameter orlumen72 of theLA catheter60. Alternatively, the cuttingcatheter80 may be positioned over theLA guide wire74 with theLA catheter60 removed.
• The cuttingcatheter80 preferably includes ahollow cutting tip82 positioned on the distal end of thecatheter shaft85, and ahub86 positioned on the proximal end. Thecatheter shaft85 may include afirst section88 and asecond section90. Thefirst section88 may be generally stiff to allow for torquability of theshaft85, and may be of a solid or braided construction. Thefirst section88 includes a predetermined length, e.g., ninety centimeters, to allow positioning of theshaft85 within the vasculature structure and the LA catheter. Thesecond section90 may be generally flexible to allow for steerability through the fossa ovalis and into the left atrium. Thesecond section90 may also include a predetermined length, e.g., twenty centimeters. Theinner diameter92 of thecatheter shaft85 is preferably sized to allow passage of theLA guide wire74. The cuttingcatheter80 preferably includes a radio-opaque marker96 positioned on theshaft85 so as to mark the depth of cut against the radio-opaque magnet head62 ormarker76 of theLA catheter60.
• The hollow cutting or penetratingtip82 includes a sharpeneddistal end98 and is preferably sized to fit through theLA catheter60 and magnetic head62 (seeFIG. 42A). Alternatively, as seen inFIGS. 42B and42C, cutting or penetratingtips100 and105 may be used in place of, or in combination with, thehollow cutting tip82. The tri-blade100 ofFIG. 42B includes a sharpdistal tip101 and three cuttingblades102, although any number of blades may be used. The tri-blade100 may be used to avoid producing cored tissue, which may be a product of thehollow cutting tip82. The elimination of cored tissue helps to reduce the possibility of an embolic complication. The sharp tippedguide wire105 shown inFIG. 42C may also be used. Thesharp tip106 is positioned on the end of a guide wire to pierce the wall of the left atrium and great cardiac vein.
• 2. Implantation Methods
• Access to the vascular system is commonly provided through the use of introducers known in the art. A 16F or less hemostasis introducer sheath (not shown), for example, may be first positioned in the superior vena cava (SVC), providing access for theGCV catheter40. Alternatively, the introducer may be positioned in the subclavian vein. A second 16F or less introducer sheath (not shown) may then be positioned in the right femoral vein, providing access for theLA catheter60. Access at both the SVC and the right femoral vein, for example, also allows the implantation methods to utilize a loop guide wire. For instance, in a procedure to be described later, a loop guide wire is generated by advancing theLA guide wire74 through the vasculature until it exits the body and extends external the body at both the superior vena cava sheath and femoral sheath. TheLA guide wire74 may follow an intravascular path that extends at least from the superior vena cava sheath through the interatrial septum into the left atrium and from the left atrium through atrial tissue and through a great cardiac vein to the femoral sheath. The loop guide wire enables the physician to both push and pull devices into the vasculature during the implantation procedure (seeFIGS. 35A and 36A).
• An optional step may include the positioning of a catheter or catheters within the vascular system to provide baseline measurements. An AcuNav™ intracardiac echocardiography (ICE) catheter (not shown), or similar device, may be positioned via the right femoral artery or vein to provide measurements such as, by way of non-limiting examples, a baseline septal-lateral (S-L) separation distance measurement, atrial wall separation, and a mitral regurgitation measurement. Additionally, the ICE catheter may be used to evaluate aortic, tricuspid, and pulmonary valves, IVC, SVC, pulmonary veins, and left atrium access.
• The GCV catheter is then deployed in the great cardiac vein adjacent a posterior annulus of the mitral valve. From the SVC, under image guidance, the 0.035 inchGCV guide wire54, for example, is advanced into the coronary sinus and to the great cardiac vein. Optionally, an injection of contrast with an angiographic catheter may be made into the left main artery from the aorta and an image taken of the left coronary system to evaluate the position of vital coronary arterial structures. Additionally, an injection of contrast may be made to the great cardiac vein in order to provide an image and a measurement. If the great cardiac vein is too small, the great cardiac vein may be dilated with a 5 to 12 millimeter balloon, for example, to midway the posterior leaflet. TheGCV catheter40 is then advanced over theGCV guide wire54 to a location in the great cardiac vein, for example near the center of the posterior leaflet or posterior mitral valve annulus (seeFIG. 23). The desired position for theGCV catheter40 may also be viewed as approximately 2 to 6 centimeters from the anterior intraventricular vein takeoff. Once theGCV catheter40 is positioned, an injection may be made to confirm sufficient blood flow around theGCV catheter40. If blood flow is low or non-existent, theGCV catheter40 may be pulled back into the coronary sinus until needed.
• TheLA catheter60 is then deployed in the left atrium. From the femoral vein, under image guidance, the 0.035 inchLA guide wire74, for example, is advanced into the right atrium. A 7F Mullins™ dilator with a trans-septal needle is deployed into the right atrium (not shown). An injection is made within the right atrium to locate the fossa ovalis on the septal wall. The septal wall at the fossa ovalis is then punctured with the trans-septal needle and theguide wire74 is advanced into the left atrium. The trans-septal needle is then removed and the dilator is advanced into the left atrium. An injection is made to confirm position relative to the left ventricle. The 7F Mullins system is removed and then replaced with a 12F or other appropriatelysized Mullins system26. The12F Mullins system26 is positioned within the right atrium and extends a short distance into the left atrium.
• As seen inFIG. 24, theLA catheter60 is next advanced over theLA guide wire74 and positioned within the left atrium. If theGCV catheter40 had been backed out to allow for blood flow, it is now advanced back into position. TheGCV catheter40 is then grossly rotated to magnetically align with theLA catheter60. Referring now toFIG. 25, preferably under image guidance, theLA catheter60 is advanced and rotated if necessary until themagnetically attractant head62 of theLA catheter60 magnetically attracts to themagnetically attractant head42 of theGCV catheter40. The left atrial wall and the great cardiac vein venous tissue separate theLA catheter60 and theGCV catheter40. The magnetic attachment is preferably confirmed via imaging from several viewing angles, if necessary.
• Next, anaccess lumen115 is created into the great cardiac vein (seeFIG. 26). The cuttingcatheter80 is first placed over theLA guide wire74 inside of theLA catheter60. The cuttingcatheter80 and theLA guide wire74 are advanced until resistance is felt against the wall of the left atrium. TheLA guide wire74 is slightly retracted, and while a forward pressure is applied to the cuttingcatheter80, the cuttingcatheter80 is rotated and/or pushed. Under image guidance, penetration of the cuttingcatheter80 into the great cardiac vein is confirmed. TheLA guide wire74 is then advanced into the great cardiac vein and further into theGCV catheter40 toward the coronary sinus, eventually exiting the body at the sheath in the neck. TheLA catheter60 and theGCV catheter40 may now be removed. Both theLA guide wire74 and theGCV guide wire54 are now in position for the next step of establishing the trans-septal bridging element12.
• B. Establish Trans-Septal Bridging Element
• Now that the posteriorbridge stop region14 has been established, the trans-septal bridging element12 is positioned to extend from the posteriorbridge stop region14 in a posterior to anterior direction across the left atrium and to the anteriorbridge stop region16.
• In this exemplary embodiment of the methods of implantation, the trans-septal bridging element12 is implanted via a left atrium to GCV approach. In this approach, theGCV guide wire54 is not utilized and may be removed. Alternatively, a GCV to left atrium approach is also described. In this approach, the GCV guide wire is utilized. The alternative GCV to left atrium approach for establishing the trans-septal bridging element12 will be described in detail in section IV.
• The bridgingelement12 may be composed of a suture material or suture equivalent known in the art. Common examples may include, but are not limited to, 1-0, 2-0, and 3-0 polyester suture, stainless steel braid (e.g., 0.022 inch diameter), and NiTi wire (e.g., 0.008 inch diameter). Alternatively, the bridgingelement12 may be composed of biological tissue such as bovine, equine or porcine pericardium, or preserved mammalian tissue, preferably in a gluteraldehyde fixed condition. Alternatively the bridgingelement12 may be encased by pericardium, or polyester fabric or equivalent.
• A bridge stop, such as a T-shapedbridge stop120 is preferably connected to the predetermined length of the bridgingelement12. The bridgingelement12 may be secured to the T-shapedbridge stop120 through the use of a bridge stop150 (seeFIG. 44A), or may be connected to the T-shapedbridge stop120 by securingmeans121, such as tying, welding, or gluing, or any combination thereof. As seen inFIGS. 43A and 43B, the T-shapedbridge stop120 may be symmetrically shaped or asymmetrically shaped, may be curved or straight, and preferably includes aflexible tube122 having a predetermined length, e.g., three to eight centimeters, and aninner diameter124 sized to allow at least a guide wire to pass through. Thetube122 is preferably braided, but may be solid as well, and may also be coated with a polymer material. Eachend126 of thetube122 preferably includes a radio-opaque marker128 to aid in locating and positioning the T-shapedbridge stop120. Thetube122 also preferably includes atraumatic ends130 to protect the vessel walls. The T-shapedbridge stop120 may be flexurally curved or preshaped so as to generally conform to the curved shape of the great cardiac vein or interatrial septum and be less traumatic to surrounding tissue. The overall shape of the T-shapedbridge stop120 may be predetermined and based on a number of factors, including, but not limited to the length of the bridge stop, the material composition of the bridge stop, and the loading to be applied to the bridge stop.
• A reinforcingcenter tube132 may also be included with the T-shapedbridge stop120. The reinforcingtube132 may be positioned over theflexible tube122, as shown, or, alternatively, may be positioned within theflexible tube122. The reinforcingtube132 is preferably solid, but may be braided as well, and may be shorter in length, e.g., one centimeter, than theflexible tube122. The reinforcingcenter tube132 adds stiffness to the T-shapedbridge stop120 and aids in preventing egress of the T-shapedmember120 through the cored or piercedlumen115 in the great cardiac vein and left atrium wall.
• Alternative T-shaped members or bridge locks and means for connecting the bridgingelement12 to the T-shaped bridge locks are described in section VI.
• As can be seen inFIG. 27, the T-shaped bridge stop120 (connected to the leading end of the bridging element12) is first positioned onto or over theLA guide wire74. Thedeployment catheter24 is then positioned onto the LA guide wire74 (which remains in position and extends into the great cardiac vein) and is used to push the T-shapedbridge stop120 through theMullins catheter26 and into the right atrium, and from the right atrium through the interatrial septum into the left atrium, and from the left atrium through atrial tissue into a region of the great cardiac vein adjacent the posterior mitral valve annulus. TheLA guide wire74 is then withdrawn proximal to the tip of thedeployment catheter24. Thedeployment catheter24 and theguide wire74 are then withdrawn just to the left atrium wall. The T-shapedbridge stop120 and the attached bridgingelement12 remain within the great cardiac vein. The length of bridgingelement12 extends from the posterior T-shapedbridge stop120, through the left atrium, through the fossa ovalis, through the vasculature, and preferably the trailing end remains accessible exterior the body. Preferably under image guidance, the trailing end of the bridgingelement12 is gently pulled, letting the T-shapedbridge stop120 separate from thedeployment catheter24. Once separation is confirmed, again the bridgingelement12 is gently pulled to position the T-shapedbridge stop120 against the venous tissue within the region of the great cardiac vein and centered over the great cardiacvein access lumen115. Thedeployment catheter24 and theguide wire74 may then be removed (seeFIG. 28).
• The trans-septal bridging element12 is now in position and extends in a posterior to anterior direction from the posteriorbridge stop region14, across the left atrium, and to the anteriorbridge stop region16. The bridgingelement12 preferably extends through the vasculature structure and extends exterior the body.
• C. Establish Anterior Bridge Stop Region
• Now that the trans-septal bridging element12 is in position, the anteriorbridge stop region16 is next to be established.
• In one embodiment, the proximal portion or trailing end of the bridgingelement12 extending exterior the body is then threaded through or around an anterior bridge stop, such as theseptal member30. Preferably, the bridgingelement12 is passed through theseptal member30 outside of the body nearest its center so that; when later deployed over the fossa ovalis, the bridgingelement12 transmits its force to a central point on theseptal member30, thereby reducing twisting or rocking of the septal member. The septal member is advanced over the bridgingelement12 in a collapsed configuration through theMullins catheter26, and is positioned within the right atrium and deployed at the fossa ovalis and in abutment with interatrial septum tissue. The bridgingelement12 may then be held in tension by way of a bridge stop20 (seeFIGS. 29 and 30). Theanterior bridge stop20 may be attached to or positioned over the bridgingelement12 and advanced with theseptal member30, or alternatively, thebridge stop20 may be advanced over the bridgingelement12 to the right atrium side of theseptal member30 after the septal member has been positioned or deployed. Alternatively, thebridge stop20 may also be positioned over theLA guide wire74 and pushed by thedeployment catheter24 into the right atrium. Once in the right atrium, thebridge stop20 may then be attached to or positioned over the bridgingelement12, and theLA guide wire74 anddeployment catheter24 may then be completely removed from the body.
• FIG. 44A is an exploded view of one embodiment of a bridge stop in accordance with the present invention. Thebridge stop150 preferably includes a tube shapedbase152 and ascrew154. Thebase152 includes afirst side156 and asecond side158, wherein use, thefirst side156 is disposed toward theseptal member30, or optionally, the first side is disposed over theseptal member hub31, and thesecond side158 is adapted to receive thescrew154. Thebase152 includes an axially configured bore160 formed therein having,threads162 beginning at thesecond side158 and extending partially within a length of thebase152, although, thebore160 may be threaded throughout its entire length. The threaded bore160 includes a predeterminedinner diameter164, sized so as to allow the base152 to be installed over a guide wire, and optionally, positioned over theseptal member hub31. Afirst channel166 and, optionally, asecond channel168 may be included within thebore160 extending from thefirst side156 to partially within thebase152 to provide for passage of the bridgingelement12 within the bridge stop150 (seeFIG. 44B).
• A male threadedportion170 ofscrew154 extends from thescrew base172 to approximately midway the length of thescrew154 and is sized to be threadably received within thebore160 of thebase152. Thescrew head174 preferably includes torquing means such asparallel surfaces176.Surfaces176 are provided to allow thescrew154 to be tightened and loosened within thebase152. Screw154 also includes abore178 formed therein, sized so as to allow thescrew154 to be installed over a guide wire, and optionally, positioned over theseptal member hub31. Afirst channel182 and, optionally, asecond channel184 may be included within the screw bore178 extending partially within thescrew154, or alternatively, throughout the entire length of the screw154 (seeFIG. 44C). Thebase152 and thescrew154 are aligned such that the channel provides for free passage of the bridgingelement12 within thebridge stop150.
• In use, thescrew154 is first partially screwed into thebase152, allowing thechannel166,168 in the base152 to mate with thechannel182,184 in thescrew154. The bridgingelement12 is then extended through the entire length of thebridge stop150, and is positioned within the channel formed within thebase152 and thescrew154. The bridgingelement12 is then tensioned and thescrew154 is torqued into the base using adriver186, such that the bridging-element12 is spooled within thebridge stop150 or around theseptal member hub31, preferably one or more times. When thescrew154 is torqued into the base all the way, the screw compresses against the bridgingelement12, preventing any relative motion of the bridging element. The bridgingelement12 can no longer move freely within thebridge stop150, fixing the position of thebridge stop150 on the bridgingelement12.
• Thedriver186 includesparallel surfaces188, which are configured to extend over thescrew head174 in a mating relationship withparallel surfaces176 on thescrew head174. Thedriver186 also includes abore190 formed therein, sized so as to allow thedriver186 to be positioned over a guide wire.
• Thebridge stop150, and alternative embodiments to be described later, have a predetermined size, e.g., eight millimeters by eight millimeters, allowing them to be positioned adjacent a septal member or a T-shaped member, for example. The bridge locks are also preferably made of stainless steel or other biocompatible metallic or polymer materials suitable for implantation.
• Additional alternative bridge stop embodiments are described in section V.
• D. Bridging Element Adjustment
• Theanterior bridge stop20 is preferably positioned in an abutting relationship to theseptal member30, or optionally may be positioned over theseptal member hub31. Thebridge stop20 serves to adjustably stop or hold the bridgingelement12 in a tensioned state to achieve proper therapeutic effects.
• With the posteriorbridge stop region14, bridgingelement12, and anteriorbridge stop region16 configured as previously described, a tension may be applied to the bridgingelement12, either external to the body at the proximal portion of the bridgingelement12, or internally, including within the vasculature structure and the heart structure. After first putting tension on the bridgingelement12, theimplant10 and associated regions may be allowed to settle for a predetermined amount of time, e.g., five seconds. The mitral valve and its associated mitral valve regurgitation are then observed for desired therapeutic effects. The tension on the bridgingelement12 may be repeatably adjusted following these steps until a desired result is achieved. Thebridge stop20 is then allowed to secure the desired tension of the bridgingelement12. The bridgingelement12 may then be cut or detached at a predetermined distance away from thebridge stop20, e.g., zero to three centimeters into the right atrium. The remaining length of bridgingelement12 may then be removed from the vasculature structure.
• Alternatively, the bridgingelement12 may be allowed to extend into the IVC and into the femoral vein, possibly extending all the way to the femoral access point. Allowing the bridging element to extend into the IVC and into the femoral vein would allow for retrieval of the bridging element in the future, for example, if adjustment of the bridging element is necessary or desired.
• The bridging element adjustment procedure as just described including the steps of placing a tension, waiting, observing, and readjusting if necessary is preferred over a procedure including adjusting while at the same time—or real-time—observing and adjusting, such as where a physician places a tension while at the same time observes a real-time ultrasound image and continues to adjust based on the real-time ultrasound image. The waiting step is beneficial because it allows for the heart and the implant to go through a quiescent period. This quiescent period allows the heart and implant to settle down and allows the tension forces and devices in the posterior and anterior bridge stop regions to begin to reach an equilibrium state. The desired results are better maintained when the heart and implant are allowed to settle prior to securing the tension compared to when the mitral valve is viewed and tension adjusted real-time with no settle time provided before securing the tension.
• FIG. 31 shows an anatomical view of mitral valve dysfunction prior to the implantation of theimplant10. As can be seen, the two leaflets are not coapting, and as a result the undesirable back flow of blood from the left ventricle into the left atrium can occur. After theimplant10 has been implanted as just described, theimplant10 serves to shorten the minor axis of the annulus, thereby allowing the two leaflets to coapt and reducing the undesirable mitral regurgitation (seeFIGS. 32 and 33). As can be seen, theimplant10 is positioned within the heart, including the bridgingelement12 that spans the mitral valve annulus, theanterior bridge stop20 andseptal member30 on or near the fossa ovalis, and theposterior bridge stop18 within the great cardiac vein.
IV. Alternative Implantation Steps
• The steps of implantation as previously described may be altered due to any number of reasons, such as age, health, and physical size of patient, and desired therapeutic effects. In one alternative embodiment, the posterior T-shaped bridge stop120 (or alternative embodiments) is implanted via a GCV approach, instead of the left atrial approach as previously described. In an additional alternative embodiment, the coring procedure of the left atrial wall is replaced with a piercing procedure from the great cardiac vein to the left atrium.
• A. GCV Approach
• As previously described, penetration of the cuttingcatheter80 into the great cardiac vein is confirmed under image guidance (seeFIG. 26). Once penetration is confirmed, theLA guide wire74 is advanced into the great cardiac vein and into theGCV catheter40. TheLA guide wire74 is further advanced through theGCV catheter40 until its end exits the body (preferably at the superior vena cava sheath). TheLA catheter60 and theGCV catheter40 may now be removed. Both theLA guide wire74 and theGCV guide wire54 are now in position for the next step of establishing the trans-septal bridging element12 (seeFIG. 35A). At this point, anoptional exchange catheter28 may be advanced over theLA guide wire74, starting at either end of theguide wire74 and entering the body at either the femoral sheath or superior vena cava sheath, and advancing theexchange catheter28 until it exits the body at the other end of theguide wire74. The purpose of this exchange catheter is to facilitate passage of theLA guidewire74 and bridgingelement12, in a procedure to be described below, without cutting or injuring the vascular and heart tissues. In a preferred embodiment, theexchange catheter28 is about 0.040 to 0.060 inch ID, about 0.070 to 0.090 inch OD, about 150 cm in length, has a lubricious ID surface, and has an atraumatic soft tip on at least one end so that it can be advanced through the vasculature without injuring tissues. It is to be appreciated that the ID, OD, and length may vary depending on the specific procedure to be performed.
• In the GCV approach, the trans-septal bridging element12 is implanted via a GCV to left atrium approach. A predetermined length, e.g., two meters, of bridging element12 (having a leading end and a trailing end) is connected at the leading end to the tip of theLA guide wire74 that had previously exited the body at the superior vena cava sheath and the femoral sheath. In this embodiment, theLA guide wire74 serves as the loop guide wire, allowing the bridging element to be gently pulled or retracted into and through at least a portion of the vasculature structure and into a heart chamber. The vascular path of the bridging element may extend from the superior vena cava sheath through the coronary sinus into a region of the great cardiac vein adjacent the posterior mitral valve annulus, and from the great cardiac vein through atrial tissue into the left atrium, and from the left atrium into the right atrium through the interatrial septum, and from the right atrium to the femoral sheath.
• As can be seen inFIGS. 34A to 34D, a crimp tube orconnector800 may be used to connect the bridgingelement12 to at least one end of theLA guide wire74.FIG. 34A shows acrimp tube800 preferably having an outerprotective shell802 and aninner tube804. The outerprotective shell802 is preferably made of a polymeric material to provide atraumatic softness to the crimp tube, although other crimpable materials may be used. Theinner tube804 may be made of a ductile or malleable material such as a soft metal so as to allow a crimp to hold the bridgingelement12 andguide wire74 in place. The crimp tube ends806 may be gently curved inward to aid in the movement of the crimp tube as thetube800 moves through the vasculature. It is to be appreciated that the crimp tube may simply comprise a single tube made of a ductile or malleable material.
• The bridgingelement12 is positioned partially within thecrimp tube800. A force is applied with a pliers or similar crimping tool to create a first crimp808 (seeFIG. 34B). The end of the bridging element may include a knot, such as a single overhand knot, to aid in the retention of the bridgingelement12 within the crimp tube. Next, theLA guide wire74 is positioned partially within thecrimp tube800 opposite the bridgingelement12. A force is again applied with a pliers or similar crimping tool to create a second crimp810 (seeFIG. 34C). Alternatively, both the bridgingelement12 and theguide wire74 may be placed within thecrimp tube800 at opposite ends and asingle crimp812 may be used to secure both the bridgingelement12 and theguide wire74 within the crimp tube (seeFIG. 34D). It is to be appreciated that thecrimp tube800 may be attached to the bridgingelement12 or guide wire prior to the implantation procedure so as to eliminate the step of crimping the bridgingelement12 within thecrimp tube800 during the implantation procedure. Theguide wire74 is now ready to be gently retracted. It can also be appreciated that apparatus that uses adhesives or alternatively pre-attached mechanisms that snap together may also be used for connecting bridge elements to guidewires.
• As can be seen inFIG. 35B, theLA guide wire74 is gently retracted, causing the bridgingelement12 to follow through the vasculature structure. If theoptional exchange catheter28 is used (as shown inFIGS. 35A and 35B), the LA guidewire74 retracts through the lumen of theexchange catheter28 without injuring tissues. TheLA guide wire74 is completely removed from the body at the femoral vein sheath, leaving the bridgingelement12 extending from exterior the body (preferably at the femoral sheath), through the vasculature structure, and again exiting at the superior vena cava sheath. TheLA guide wire74 may then be removed from the bridgingelement12 by cutting or detaching the bridgingelement12 at or near thecrimp tube800.
• A posterior bridge stop, such as a T-shapedbridge stop120 is preferably connected to the trailing end of bridgingelement12 extending from the superior vena cava sheath. The T-shapedbridge stop120 is then positioned onto or over theGCV guide wire54. Adeployment catheter24 is then positioned onto or over theGCV guide wire54 and is used to advance or push the T-shapedbridge stop120 and bridgingelement12 through the right atrium, through the coronary sinus, and into the great cardiac vein. If theoptional exchange catheter28 is used, the exchange catheter is gently retracted with the bridgingelement12 or slightly ahead of it (seeFIGS. 36A and 36B). Optionally, the bridgingelement12 may be pulled from the femoral vein region, either individually, or in combination with thedeployment catheter24, to advance the T-shapedbridge stop120 and bridgingelement12 into position in the great cardiac vein. TheGCV guide wire54 is then retracted letting the T-shapedbridge stop120 separate from theGCV guide wire54 anddeployment catheter24. Preferably under image guidance, and once separation is confirmed, the bridgingelement12 is gently pulled to position the T-shapedbridge stop120 in abutment against the venous tissue within the great cardiac vein and centered over theGCV access lumen115. Thedeployment catheter24 andoptional exchange catheter28 may then be removed.
• The T-shapedbridge stop120 and the attached bridgingelement12 remain within the great cardiac vein. The length of bridgingelement12 extends from the posterior T-shapedbridge stop120, through the left atrium, through the fossa ovalis, through the vasculature, and preferably remains accessible exterior the body. The bridgingelement12 is now ready for the next step of establishing the anteriorbridge stop region16, as previously described, and as shown inFIGS. 28 to 30.
• B. Piercing Procedure
• In this alternative embodiment the procedure to core a lumen from the left atrium into the great cardiac vein is replaced with a procedure where a sharp-tipped guide wire within the great cardiac vein is used to create a passage from the great cardiac vein into the left atrium. Alternative embodiments for the magnetic head of both theGCV catheter40 and theLA catheter60 are preferably used for this procedure.
• FIGS. 45A and 45B show an end to side polarity embodiment for the GCV cathetermagnetic head200 and the LA cathetermagnetic head210. Alternatively, a side to side polarity may be used. The GCV cathetermagnetic head200 can maintain the same configuration for both the end to side polarity and the end to end polarity, while the LA cathetermagnetic head215 is shown essentially rotated ninety degrees for the side to side polarity embodiment (seeFIG. 46).
• As seen inFIG. 45B, the GCV cathetermagnetic head200 includes a dual lumen configuration. A navigationguide wire lumen202 allows theGCV guide wire54 to extend through the cone or bullet shapedend204 of thehead200 in order to steer theGCV catheter40 into position. A second radially curvedside hole lumen206 allows the sharp tipped guide wire105 (or tri-blade100, for example) to extend through thehead200 and directs the sharp tippedguide wire105 into the LA cathetermagnetic head210. The LA cathetermagnetic head210 includes a funneledend212 and a guide wire lumen214 (seeFIG. 45C). The funneledend212 directs the sharp tippedguide wire105 into thelumen214 and into theLA catheter shaft65.
• FIG. 46 shows the alternative embodiment of the LA cathetermagnetic head215 used with the side to side polarity embodiment. Thehead215 may have the same configuration as the GCV cathetermagnetic head42 shown inFIGS. 39 and 40 and described in section III. Thehead215 includes a navigationguide wire lumen216 at the cone or bullet shapedend218, and aside hole220. Theside hole220 funnels the sharp tipped guide wire105 (or tri-blade100, for example), from theGCV catheter40 to theLA catheter60 and directs theguide wire105 into theLA catheter shaft65.
• In use, both theGCV catheter40 and theLA catheter60 are advanced into the great cardiac vein and left atrium as previously described. TheGCV catheter40 and theLA catheter60 each includes the alternative magnetically attractant head portions as just described. As best seen inFIGS. 45A and 45B, a sharp-tippedguide wire105 is advanced through theGCV catheter40 to the internal wall of the great cardiac vein. The sharp-tippedguide wire105 is further advanced until it punctures or pierces the wall of the great cardiac vein and the left atrium, and enters the funneledend212 within theLA catheter head210. The sharp-tippedguide wire105 is advanced further until it exits the proximal end of theLA catheter60. Both theGCV catheter40 and theLA catheter60 may now be removed, leaving theGCV guide wire54 and the sharp-tippedguide wire105 in place. The posterior T-shapedbridge stop120 is now implanted via the GCV approach, as previously described, and as shown inFIGS. 35A to 36B.
V. Alternative Bridge Stop Embodiments
• Additional alternative embodiments of bridge stop devices may be used and are herein described. The bridge stop serves to secure the bridgingelement12 at the posterior or anteriorbridge stop region14,16, or both.
• FIGS. 47A and 47B are perspective views of an alternative embodiment of abridge stop300 in accordance with the present invention. Thebridge stop300 preferably includes a fixedupper body302 and a movablelower body304. Alternatively, theupper body302 may be movable and thelower body304 may be fixed. Theupper body302 andlower body304 are positioned circumjacent a tubular shapedrivet306. Theupper body302 andlower body304 are preferably held in position by therivet head308 and abase plate310. Therivet306 andbase plate310 includes a predeterminedinner diameter312, sized so as to allow thebridge stop300 to be installed over a guide wire. A spring, such as aspring washer314, or also known in the mechanical art as a Belleville Spring, is positioned circumjacent therivet306 and between therivet head308 and theupper body302, and applies an upward force on thelower body304. Thelower body304 is movable between a bridge unlocked position (seeFIG. 47A), and a bridge locked position (seeFIG. 47B). In the bridge unlocked position, thelower body304 and theupper body302 are not in contacting communication, creating agroove320 between theupper body302 andlower body304. In the bridge locked position, the axial force of thespring washer314 urges thelower body304 into contacting, or near contacting communication with theupper body302, whereby the bridgingelement12, which has been positioned within thegroove320, is locked in place by the axial force of thelower body304 being applied to theupper body302.
• In use, the bridgingelement12 is positioned within thegroove320 while thelower body304 is maintained in the bridge unlocked position316. Thebridge stop300 is positioned against theseptal member30 and the bridgingelement12 is adjusted to proper tension. Thelower body304 is then allowed to move toward theupper body302; thereby fixing the position of thebridge stop300 on the bridgingelement12.
• FIGS. 48A and 48B are perspective views of an alternative embodiment of the bridge stop350 shown inFIGS. 47A and 47B. Thebridge stop400 preferably includes an extension ortension spring402 wherein at least one revolution of the spring coils404 is in a contacting relationship while thespring402 is in a natural or no-load position. When in a tensioned state, the at least one revolution of the spring coils404 is in a non-contacting relationship. In use, an axial tension force is applied to thespring402, allowing the spring coils404 to separate (seeFIG. 48A). While in the tensioned state, the bridgingelement12 is positioned between and/or around at least one, and preferably multiple spring coils404. Thebridge stop400 is positioned against theseptal member30 and the bridgingelement12 is adjusted to proper tension. The tension force is then removed from thespring402 and thespring404 is allowed to return to its no-load state (seeFIG. 48B). In the spring's no-load state, thecoils404 provide a tight fit against the bridgingelement12, thereby fixing the position of thebridge stop400 on the bridgingelement12.
• FIG. 49 is a cross sectional view of an alternative embodiment of abridge stop450 in accordance with the present invention. Thebridge stop450 preferably includes aplunger452 within atube454. Thetube454 includes aplunger bore456 extending partially through the length of thetube454. Thebore456 then tapers inward at460 creating asmaller bore462. An internally threadedportion466 of plunger bore456 extends from thefirst side468 of thetube454 to approximately midway between thefirst side468 and thesecond side470 oftube454. Alternatively, the threadedportion466 may be external on thetube454. Theplunger452 is positioned within the plunger bore456. Theplunger452 has a conical shapedhead472 and ashaft474 extending from thebase476 of the conical shapedhead472. Atorque screw478, having afirst side480 and asecond side482, is threaded intobore456. Thefirst side480 includes receiver means for a driver tool to rotate thetorque screw478, such as, but not limited to phillips, slotted, six lobe, or square. Thesecond side482 includes apocket484. Acompression spring486 having afirst end488 is positioned within thepocket484, and asecond end490 of thecompression spring486 is positioned over theshaft474 of theplunger452.
• Anaperture492 is disposed within the wall of theshaft474 at a point above where the plunger bore456 begins to taper inward. Bridgingelement12 is shown disposed through thesmall bore462 and throughaperture492.
• In use, thetorque screw478 may be backed off to allow theplunger head472 to move away from the taperedportion460 of the plunger bore456. Bridgingelement12 is disposed withinbore462 and extends out of thetube454 ataperture492. Thebridge stop450 is then positioned against theseptal member30 and the bridgingelement12 is adjusted to proper tension. Thetorque screw478 is then torqued into thebore456, causing theplunger head472 to provide a tight fit against the bridgingelement12, thereby fixing the position of thebridge stop450 on the bridgingelement12.
• FIG. 50 is a cross sectional view of an additional alternative embodiment of abridge stop550 in accordance with the present invention. Thebridge stop550 preferably includes abase portion552 having afirst side554 and asecond side556, acap558 threaded over thebase portion552, and acollet560 positioned between thesecond side556 of thebase552 and thecap558. Thecollet560 is seated on thesecond side556 of thebase552. Abore562 extends axially through thebase552,collet560, andcap558. In use, thecap558 may be backed off to allow thebore562 within thecollet560 to expand sufficiently to allow thebridging element12 to slide freely through thebridge stop550. Thebridge stop550 is then positioned against theseptal member30 and the bridgingelement12 is adjusted to proper tension. Thecap558 is then tightened onto thebase552, which causes thebore562 within thecollet560 to close down. Thecollet560 provides a tight fit against the bridgingelement12, thereby fixing the position of thebridge stop550 on the bridgingelement12.Collet560 can be made of an elastomer or deformable type of material to make the pinching force more distributed and less traumatic to the bridgingelement12.
• FIG. 51 is a perspective view of an additional alternative embodiment of abridge stop650 in accordance with the present invention. Thebridge stop650 comprises ahousing652 having alid654. Thebridge stop650 may be tubular in shape, and may include an axially positionedlumen656 extending therethru; thelumen656 being sized to allow thebridge stop650 to be positioned over a guide wire for implantation and optionally secured tohub31 of theseptal member30. A second radially offsetaxial lumen658 also extends through thebridge stop650. Thesecond lumen658 allows for passage of the bridgingelement12 through thebridge stop650.
• Positioned within thehousing652 is aspring band660 and aspacer662. Thespring band660 is generally circular in shape and has a fixedend664 and afree end666. Thefixed end664 includes atab668 positioned within aslot670 in thelid654 to prevent movement of the fixed end. Thefree end666 includes aninclined angle672 which allows for circumferential displacement when theinclined angle672 is depressed. Thespacer662 is positioned adjacent thespring band660, and keeps the spring band in alignment and free of buckling. As seen inFIG. 51, ascrew674 may be positioned in thelid654, and when turned into thebridge stop650, thescrew674 provides a force on theinclined angle672. Thefree end666 of thespring band660 is caused to rotate toward thefixed end664, thereby pinching the bridgingelement12 within the bridge stop650 (between thefixed end664 and the free end666), and fixing the position of thebridge stop650 on the bridgingelement12.
• It is to be appreciated that each embodiment of the bridge stop may be configured to have a bridge securing configuration in its static state, so as to require a positive actuation force necessary to allow the bridging element to move freely within or around the bridge stop. When a desirable tension in the bridge element is achieved, the actuation force is removed, thereby returning the bridge stop back to its static state and securing the bridge stop to the bridging element. Alternatively, the bridge stop may be configured to allow free movement of the bridgingelement12 in its static state, thereby requiring a positive securing force to be maintained on the bridge stop necessary to secure the bridging element within the bridge stop.
• Preferably, the bridge securing feature is unambiguous via tactile or fluoroscopic feedback. The securing function preferably may be locked and unlocked several times, thereby allowing the bridging element to be readjusted. The bridge stop material is also desirably radio-opaque or incorporates radio-opaque features to enable the bridge stop to be located with fluoroscopy.
VI. Alternative T-Shaped Bridge Stop Embodiments
• Additional alternative embodiments of T-shaped bridge stop devices may be used and are herein described. The T-shaped bridge stop may serve to secure the bridgingelement12 at the anteriorbridge stop region16, or the posteriorbridge stop region14, or both. It is to be appreciated that the alternative embodiments of the T-shaped bridge stop devices may be symmetrical as shown, or may also be asymmetrically shaped.
• FIG. 52A is a perspective view of an alternative embodiment of a T-shapedbridge stop700 in accordance with the present invention. The T-shapedbridge stop700 preferably includes anintravascular stent702 and, optionally, a reinforcingstrut704. Thestent702 may be a balloon expandable or self expanding stent. As previously described, the T-shapedbridge stop700 is preferably connected to a predetermined length of the bridgingelement12. The bridgingelement12 may be held within, on, or around the T-shapedbridge stop700 through the use of any of the bridge locks as previously described, or may be connected to the T-shapedbridge stop700 by way of tying, welding, or gluing, for example, or any combination.
• FIG. 52B is a perspective view of an alternative embodiment of the T-shapedbridge stop700 in accordance with the present invention. The alternative T-shapedbridge stop701 preferably includes a lattice or half roundintravascular stent703 and, optionally, a reinforcingstrut704. The “C” shapedstent703 may be a balloon expandable stent or self expanding stent. As previously described, the T-shapedbridge stop701 is preferably connected to a predetermined length of the bridgingelement12. The bridgingelement12 may be held within, on, or around the T-shapedbridge stop701 through the use of any of the bridge locks as previously described, or may be connected to the T-shapedbridge stop701 by way of tying, welding, or gluing, for example, or any combination.
• FIGS. 53A to 53E show alternative methods of connecting the bridgingelement12 to a T-shapedbridge stop710.FIG. 53A shows a T-shapedmember710 where the bridgingelement12 is wound around the T-shapedmember710. The bridgingelement12 may be secured by adhesive712, knot, or a securing band placed over the bridgingelement12, for example. Alternatively, the bridgingelement12 may first be threaded through alumen714 extending through the T-shapedmember710 perpendicular the length of the T-shaped member. The bridgingelement12 may then be wound around the T-shaped member, and secured by adhesive712, securing band, or knot, for example.
• FIG. 53B shows a T-shapedmember710 where the bridgingelement12 is welded or forged to aplate716. Theplate716 may then be embedded within the T-shapedmember710, or alternatively, secured to the T-shapedmember710 by gluing or welding, for example.
• FIGS. 53C and 53D show alternative embodiments where a ball andsocket joint718 connects the bridgingelement12 to the T-shapedmember710. InFIG. 53C, the ball andsocket joint718 is located external to the T-shapedmember710. Alternatively, the ball and socket joint718 may be positioned partially or completely within the T-shapedmember710, as seen inFIG. 53D. The bridgingelement12 is secured to thesocket720, and theball722 is secured to the T-shapedmember710. The ball andsocket joint718 allows for free rotation of the bridgingelement12 relative to the T-shapedmember710 or vice versa. The ball andsocket joint718 is preferably made of a micro-machined stainless steel, although other implantable materials may be used as well.
• FIG. 53E shows an additional alternative embodiment of the T-shapedmember710 where the bridgingelement12 is embedded in apolymeric substrate724 of the T-shapedmember710. In this embodiment, the bridgingelement12 preferably is a braided stainless steel micro-cable. Theend726 of the bridgingelement12 is separated into an assortment ofstrands728, which are then embedded in thepolymeric substrate724.
• FIG. 53F shows a guide wire or bridging element style hinged T-shapedbridge stop embodiment730 having a hingedleg732. When in the expanded state, as shown inFIG. 53F, the hingedleg732 forms one arm of a “T.” The hingedleg732 has a “C” shaped or concave profile, allowing the hingedleg732 to lie over the guide wire or bridgingelement12 while tracking to its final location. When the guide wire or bridgingelement12 is gently retracted, the hingedleg732 pivots away from the bridgingelement12 forming the T-shaped bridge stop.
VII. Alternative Anterior Bridge Stop Embodiments
• In place of, or in combination with theseptal member30 previously described, alternative embodiments of an anterior bridge stop may be used.
• FIG. 54 shows animplant10 having a T-shapedbridge stop710 in the great cardiac vein and an anterior T-shapedbridge stop750. The anterior T-shapedbridge stop750 may be of a construction of any of the T-shaped bridge stop embodiments described. The T-shapedmember750 includes alumen752 extending through the T-shapedmember750 perpendicular to the length of the T-shaped member. The bridgingelement12 may be secured by a free floating bridge stop as previously described.
• FIG. 55 shows animplant10 having a T-shapedbridge stop710 in the great cardiac vein and an anterior latticestyle bridge stop760. Thelattice762 is positioned on the septal wall at or near the fossa ovalis. Optionally, thelattice762 may include areinforcement strut764 to distribute the bridgingelement12 tension forces over a greater area on the septal wall. The anterior latticestyle bridge stop760 may be packed in a deployment catheter with the bridgingelement12 passing through its center. Thelattice762 is preferably self expanding and may be deployed by a plunger. The bridgingelement12 may be secured by a free floating bridge stop as previously described.
• FIG. 56A shows animplant10 having a T-shapedbridge stop710 in the great cardiac vein and an anterior star shapedbridge stop770. Thestar772 is positioned on the septal wall at or near the fossa ovalis. The star shapedbridge stop770 may be packed in a deployment catheter with the bridgingelement12 passing through its center. Thestar772 is preferably self expanding and may be deployed by a plunger. When the star shapedbridge stop770 is deployed, thecenter portion774 stands proud of the septal wall to concentrate forces to the star points776 (seeFIG. 56B). The bridgingelement12 may be secured by a free floating bridge stop as previously described.
• FIG. 57 shows an additional embodiment of ananterior bridge stop820. Thebridge stop820 includes at least twoarms822 extending radially from a generallycentral portion824, and preferably includes more than two arms, as shown inFIG. 57. Thebridge stop820 is positioned on the septal wall at or near the fossa ovalis. Thebridge stop820 may be packed in a deployment catheter with the bridgingelement12 passing through itscenter lumen826. The bridge stop is preferably self expanding and may be deployed by a plunger after being folded into a catheter. The bridgingelement12 may be secured by a free floating bridge stop as previously described or fixed in position.
• FIG. 58 shows an additional embodiment of ananterior bridge stop830. Thebridge stop830 again includes at least twoarms832, and preferably includes more than two. In this embodiment, eacharm832 is an independent member, and is free to move relative to the remaining arms. Thebridge stop830 is positioned on the septal wall at or near the fossa ovalis. Thebridge stop830 may be packed in a deployment catheter with the bridgingelement12 passing through alumen836 in each arm; the lumen being located generally central along the longitudinal axis of each arm. The bridge stop is preferably self expanding and may be deployed by a plunger. The bridgingelement12 may be secured by a free floating bridge stop as previously described or fixed in position.
• FIG. 59 shows an additional embodiment of ananterior bridge stop840. Thebridge stop840 includes at least onemain trunk842, and at least onearm844 extending radially from thetrunk842, and preferably more than one arm, as shown inFIG. 59. Thebridge stop840 is positioned on the septal wall at or near the fossa ovalis. Thebridge stop840 may be packed in a deployment catheter with the bridgingelement12 passing through alumen846; the lumen being located generally central along the longitudinal axis of thetrunk842. The bridge stop is preferably self expanding and may be deployed by a plunger. The bridgingelement12 may be secured by a free floating bridge stop as previously described or fixed in position.
• FIG. 60A shows an additional embodiment of ananterior bridge stop850. Thebridge stop850 includes at least onearm852 extending radially from a generallycentral portion854, and preferably includes more than one arm, as shown inFIG. 60A. Thebridge stop850 is positioned on the septal wall at or near the fossa ovalis. Thebridge stop850 may be packed in adeployment catheter24 with the bridgingelement12 passing through its center lumen856 (seeFIG. 60B.). Thebridge stop850 may be self expanding and may be deployed by a plunger, or alternatively may be deployed by applying tension on adeployment wire858 and pushing on the plunger to expand the at least onearm852. The forces of thedeployment wire858 and plunger cause thebridge stop850 to be plastically deformed into its final shape. The bridgingelement12 may be secured by a free floating bridge stop as previously described or fixed in position.
• FIGS. 61A to 62B show additional embodiments of an anterior bridge stop incorporating the use of porcine or equine pericardium to spread the tension forces of the bridgingelement12, and also to provide a padding surface to the septal wall and to promote the bridge stop's ingrowth within the septal wall tissue.
• As can be seen inFIG. 61A, apad862 of pericardium is positioned on the septal wall side of abridge stop860. Thebridge stop860 as shown includes a plurality ofarms864 extending radially from a generallycentral portion866. Thebridge stop860, including thepericardium pad862, is positioned on the septal wall at or near the fossa ovalis, with thepericardium pad862 positioned between the septal wall and thebridge stop860. Thebridge stop860 andpericardium pad862 may be packed in adeployment catheter24 with the bridgingelement12 passing through both thebridge stop860 and the pericardium pad862 (seeFIG. 61B). Thebridge stop860, including thepericardium pad862, is preferably self expanding and may be deployed by a plunger. The bridgingelement12 may be secured by a free floating bridge stop as previously described or fixed in position.
• FIG. 62A shows an alternative embodiment of thebridge stop860.FIG. 62A shows abridge stop870 positioned between at least two layers ofpericardium872.Pericardium872 may be a single piece of pericardium having a butterfly cut to allow thebridge stop870 to be positioned between the two layers, or the pericardium may include at least two separate pads, so as to allow thebridge stop870 to be positioned between the at least two pads. Thebridge stop870 as shown includes a plurality ofarms874 extending radially from a generallycentral portion876. Thebridge stop870, including thepericardium pad872, is positioned on the septal wall at or near the fossa ovalis, with one layer of thepericardium pad872 being positioned between the septal wall and thebridge stop870, and the other layer ofpericardium872 exposed to the right atrium. Thebridge stop870 andpericardium pad872 may be packed in adeployment catheter24 with the bridgingelement12 passing through both thebridge stop870 and the pericardium pad872 (seeFIG. 62B). Thebridge stop870, including thepericardium pad872, is preferably self expanding and may be deployed by a plunger. The bridgingelement12 may be secured by a free floating bridge stop as previously described or fixed in position.
• Both bridge stopembodiments860 and870 may include any of the self-expanding embodiments described herein, and as shown are non-limiting embodiments for incorporation with a pericardium pad or pads. It should also be appreciated thatpads862 and872 may be composed of biological tissue other than pericardium and further may be lined with polyester fabric or equivalent to promote tissue in-growth.
• FIGS. 63A to 63C show an additional embodiment of an inflatableanterior bridge stop880. Thebridge stop880 includes aballoon portion882 and acentral portion884. Theballoon portion882 may take on any number of shapes, and is shown as a loop or ring. Thecentral portion884 may comprise a fabric or other implantable material to allow for tissue ingrowth. Theballoon882 may be inflated with a glue material in a liquid state, such as an epoxy glue, or other materials that will harden allowing the balloon to maintain its expanded configuration. The resulting pressure from the inflation process encourages theballoon portion882 and thecentral portion884 to expand to its deployed configuration. When the balloon inflation material has hardened, the hoop or ring shaped balloon spreads the tension force from the bridgingelement12 and keeps the central fabric portion open and flat. Thebridge stop880 is positioned on the septal wall at or near the fossa ovalis. Thebridge stop880 may be packed in adeployment catheter24 with the bridgingelement12 passing through alumen886 in the central portion884 (seeFIG. 63B). The bridge stop is preferably self expanding and may be deployed by a plunger.FIG. 63C shows thebridge stop880 just after exiting thedeployment catheter24 and prior to inflation of theballoon portion882. The bridgingelement12 may be secured by a free floating bridge stop as previously described or fixed in position.
VIII. Fixed Length Bridging Element for Predetermined Tension Across a Heart Valve Annulus or for Predetermined Reduction in Septal-Lateral Length
• In order to achieve desired septal-lateral mitral valve dimension, the proper bridge length between the fossa ovalis and the GCV must be selected.
• The septal-lateral mitral valve annulus length and the fossa ovalis to GCV length may be readily assessed using three dimensional echocardiography or magnetic resonance imaging, for example, either prior to or during the implantation procedure in order to properly size the fixed length bridging element prior to implantation.
• FIGS. 64 to 66 show embodiments of animplant system910 having a fixed length bridging element. Implantation of theimplant910 having a fixed length bridging element is similar to the implantation of theimplant10 andadjustable bridging element12 as previously described, except that the bridging element is of a fixed length and is not adjusted during or after implantation. The overall length of the fixed length bridging element may be chosen as a percentage, e.g., 125 to 150 percent, of the desired septal-lateral length. The length of the fixed length bridging element will always be greater than the desired septal-lateral length.
• Normal septal-lateral distances measured in normal persons may be used as a basis for determining the proper therapeutic septal-lateral distances in persons being treated. Target therapeutic septal-lateral distance may, for example, be chosen as some percentage, e.g. 125 percent, of septal-lateral distance in normal persons. The target septal-lateral distance must be sufficient to produce a therapeutic reduction in mitral regurgitation, but not over-stretch or tear tissues.
• The use of a fixed length bridging element may reduce the complexity of the implantation of theimplant system910 because adjustment of a bridging element is not required. The implant system may also reduce the overall length of time for the implantation procedure.
• The fixed length bridging element may be generally straight, as shown inFIG. 67, or may be generally arched or non-linear, as shown inFIGS. 68 and 69.FIGS. 65 and 66 show a sample of alternative deviations of the path of the arched fixedlength bridging element932, similar to those shown inFIGS. 12 to 20. Any single deviation or combinations of lateral or medial deviations and/or superior or inferior deviations in this path can be imparted, if desired, to affect the nature and direction of the force vector or vectors that theimplant910 applies. It should be appreciated that the fixed length bridging element can be preformed or otherwise configured with various medial/lateral and/or inferior/superior deviations to achieve targeted annulus and/or atrial structure remodeling, which takes into account the particular therapeutic needs and morphology of the patient. In addition, deviations in the path of the fixed length bridging element may also be imparted in order to avoid the high velocity blood path within a heart chamber, such as the left atrium. Also, stainless steel and Nitinol bridge elements may be used (as previously described and represented byFIGS. 13 to 17 and19) that have curved septal to lateral components that impart desired ranges of tension and length in combination.
• A. Fixed Length Bridging Element Structure
• The fixed length bridging element may be constructed of a generally rigid material, such as stainless steel, in order to provide a predetermined reduction in the septal-lateral length, while allowing a wider range of tension across the heart valve annulus. Alternatively, the fixed length bridging element may be constructed of a semi-flexible or springy material, such as Nitinol, in order to provide a predetermined narrow range of tension across a heart valve annulus, such as the mitral valve annulus. A semi-flexible or springy material also facilitates the implantation of the fixed length bridging element using a deployment catheter. Nitinol has favorable fatigue properties and is also non-thrombogenic.
• As shown inFIG. 67, the fixedlength bridging element912 comprises ahollow tube920 having a connective or retentive member orhead922 at a first end and a retainer or stop924 at a second end. The inner diameter of thehollow tube920 must be large enough to enclose bridgingelement12. Thehead922 is preferably cone or chevron shaped and may include at least one crevice or slit926 sized to allow each portion of thehead922 to flex so that the head can be inserted into a receivingaperture123 in a T-shaped member orbridge stop120 and snap into place (seeFIGS. 70A and 70B). Thestop924 at the second end of thehollow tube920 may be any practical shape (i.e. circular, square, triangle, or rod shaped) that offers sufficient surface area to abut theseptal member30 without allowing thestop924 of the fixedlength bridging element912 to pass through the septal member. Alternatively, aseptal member30 may not be used and thestop924 may abut the septal wall. Stop924, for example, may incorporate any of the bridge stop embodiments described herein, and more particularly may incorporate any of the embodiments described inFIGS. 54 to 63C.
• As previously described in relation to theimplant10, thestop924 and thebridge stop120 remain free to move back and forth independent of the inter-atrial septum and the inner wall of the great cardiac vein during a portion of the cardiac cycle when the tension force may be reduced or becomes zero (seeFIGS. 71A and 71B).
• FIGS. 68 and 69 show an alternative embodiment of a fixed length bridging element. The arched fixedlength bridging element932 comprises ahollow tube940 having a connective orretentive head942 at a first end and a retainer or stop944 at a second end. Thehead942 is preferably cone or chevron shaped and may include at least one crevice or slit946 sized to allow each portion of thehead942 to flex so that the head can be inserted into a receivingaperture123 in a T-shaped member orbridge stop120 and snap into place (seeFIGS. 70A and 70B). Thestop944 at the second end of thehollow tube940 may be any practical shape (i.e. circular, square, triangle, or rod shaped) that offers sufficient surface area to abut theseptal member30 without allowing thestop944 of the fixedlength bridging element932 to pass through theseptal member30. Alternatively, aseptal member30 may not be used and thestop944 may abut the septal wall. Stop944, for example, may incorporate any of the bridge stop embodiments described herein, and more particularly may incorporate any of the embodiments described inFIGS. 54 to 63C.
• As previously described in relation to theimplant10, thestop944 and thebridge stop120 remain free to move back and forth independent of the inter-atrial septum and the inner wall of the great cardiac vein during a portion of the cardiac cycle when the tension force may be reduced or becomes zero (seeFIGS. 71A and 71B).
• B. Detailed Methods for Fixed Length Bridging Element Implantation
• The steps of implantation and implantation apparatus as described in sections III(A) “Establish Posterior Bridge Stop Region” and III(B) “Establish Trans-Septal Bridging Element” are also used in conjunction with the implantation of the fixedlength bridging element912 and932 and are therefore not repeated here. The remaining steps for implantation of the fixed length bridging element are described below. In addition, the bridgingelement12 as described in these steps takes on an alternative purpose of serving as a “tracking rail” for delivery of the fixed length bridging element to its final implanted position.
• 1. Establish Anterior Bridge Stop Region
• Now that the trans-septal bridging element or trackingrail12 is in position, the anteriorbridge stop region16 is next to be established. In an alternative embodiment not incorporating aseptal member30, the step including the deployment of theseptal member30 may be skipped.
• As seen inFIG. 29, theLA guide wire74 is first backed out to at least the right atrium. In one embodiment incorporating aseptal member30, the proximal portion of the trackingrail12 extending exterior the body is then threaded through or around theseptal member30. Preferably, the trackingrail12 is passed through theseptal member30 outside of the body nearest its center so that when the fixedlength bridging element912 later passes over the trackingrail12, thestop924 of the fixedlength bridging element912 will also be centered and will transmit its force to a central point on theseptal member30, thereby reducing twisting or rocking of the septal member. The septal member is advanced over the trackingrail12, through the vasculature; and is positioned within the right atrium and deployed at the fossa ovalis in a manner consistent with the manufacturer's instructions. At this point, tension may be applied under image guidance to establish the appropriate tension and/or length of bridging needed.
• 2. Fixed Length Bridging Element Positioning
• With the posteriorbridge stop region14, trackingrail12, and anteriorbridge stop region16 configured as described, the fixedlength bridging element912,932 is next to be positioned. External the body, the fixedlength bridging element912,932 is positioned over the trackingrail12 having an end remaining external the body. With a tension maintained on the trackingrail12, thedeployment catheter24 may then be used to gently push the fixedlength bridging element912,932 through the vasculature and into the right atrium, following the path of the trackingrail12. When aseptal member30 is used, additional pushing of thedeployment catheter24 allows the shaped head of the fixedlength bridging element912,932 to pass through the interstices of theseptal member30 until thestop924,944 of the fixed length bridging element comes to rest on theseptal member30 and restricts further passage (seeFIG. 72). When aseptal member30 is not used, thestop924,944 comes to rest on the septal wall and restricts further passage.FIG. 73 shows the deployment of the arched fixedlength bridging element932 without the use of a septal member, and prior to the deployment of thestop944.
• Still with continued tension maintained on the trackingrail12, a compressive force is applied to thedeployment catheter24 causing the shapedhead922,942 to continue to follow the path of the trackingrail12 directly into the receivingaperture123 in the T-shapedmember120. The shapedhead922,942 snaps into place within theaperture123 in the T-shaped member (seeFIGS. 70A and 70B). The trackingrail12 may then be cut or detached, leaving a portion free to dangle or recoil within thetube920,940 of the fixed length bridging element, with the remainder removed along with thedeployment catheter24.
• Alternatively, the trackingrail12 may be allowed to extend into the IVC and into the femoral vein, possibly extending all the way to the femoral access point. Allowing the tracking rail to extend into the IVC and into the femoral vein would allow for future retrieval of the tracking rail, which would provide for access to the fixed length implant.
• The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.

Claims (7)

1. A system comprising

an implant sized and configured for placement within a heart chamber,

a guide wire sized and configured for deployment in an intravascular path that extends from a first vascular access into the heart chamber and from the heart chamber to a second vascular access site different than the first vascular access site, the guide wire having a first end extending beyond the first vascular access site and a second end extending beyond the second vascular access site, and

a connector to connect an end of the implant to one end of the guide wire such that pulling on the other end of the guide wire pulls the implant along at least a portion of the intravascular path into the heart chamber.

2. A system according toclaim 1

wherein the implant comprises a metallic material or polymer material or a metallic wire form structure or a polymer wire form structure or suture material or equine pericardium or porcine pericardium or bovine pericardium or preserved mammalian tissue.

3. A system comprising

a bridge element sized and configured to be implanted within the left atrium between the great cardiac vein and the interatrial septum, the bridge element having opposite ends,

a guide wire sized and configured to be deployed in an intravascular path that extends from a first vascular access site through an interatrial septum into the left atrium and from the left atrium through a great cardiac vein to a second vascular access site that is different than the first vascular access site, the guide wire having a first end extending beyond the first vascular access site and a second end extending beyond the second vascular access site,

a connector to connect an end of the bridge element to one end of the guide wire such that pulling on the other end of the guide wire pulls the bridge element along at least a portion of the intravascular path into the left atrium,

a posterior bridge stop sized and configured to be secured to an end of the bridging element to abut against venous tissue within the great cardiac vein, and

an anterior bridge stop sized and configured to be secured to the bridging element to abut against tissue on the interatrial septum within the right atrium.

4. A system according toclaim 3

wherein the guide wire extends along the intravascular path from the first vascular access site into a right atrium through a vena cava, from the right atrium through the interatrial septum into the left atrium, from the left atrium into and through a great cardiac vein into the right atrium, and from the right atrium through a vena cava to a second vascular access site different than the first vascular access site.

5. A system according toclaim 3

wherein the guide wire extends along the intravascular path from the first vascular access site into a right atrium through an IVC, from the right atrium through the interatrial septum into the left atrium, from the left atrium into and through a great cardiac vein into the right atrium, and from the right atrium through the SVC to a second vascular access site different than the first vascular access site.

6. A system according toclaim 3

wherein the bridge element comprises a metallic material or polymer material or a metallic wire form structure or a polymer wire form structure or suture material or equine pericardium or porcine pericardium or bovine pericardium or preserved mammalian tissue.

7. A system according toclaim 3

wherein the posterior bridge stop and the anterior bridge stop place the bridge element in tension between the interatrial septum and the great cardiac vein.

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