US20060135970A1 - Catheter-based tissue remodeling devices and methods - Google Patents

Abstract

Devices and methods utilizing a catheter to remodel soft tissue of a patient and, in a preferred embodiment, to reduce the volume of the left ventricle of a heart. In one embodiment, one or more sutures are passed through a wall of the ventricle. The ends of the one suture and, more preferably, the multiples sutures are drawn together to draw tissue portions towards one another. In another embodiment, tissue remodeling clip is implanted into a wall of the ventricle. Ends of the clip are resiliently biased to move relative to one another to draw tissue portions towards one another. In yet another embodiment, a tissue remodeling anchor includes a base and a plurality of legs attached to the base. The legs of the tissue anchor are implanted into a wall of the ventricle and moved toward one another to draw tissue portions toward one another. A retaining member is positioned on the tissue anchor to prevent the legs from moving apart.

Description

RELATED APPLICATIONS
• This application is related to, and claims priority from, U.S. Provisional Patent Application No. 60/627,821, filed Nov. 15, 2004, the entirety of which is hereby incorporated by reference herein and made a part of the present disclosure.
BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to methods for remodeling soft tissue of a patient and, preferably, for remodeling the left ventricle of a patient's heart. The present invention also relates to systems for accomplishing the preferred methods.
• 2. Description of the Related Art
• Congestive heart failure is a description given to a myriad of symptoms that may be the result of the heart's inability to meet the body's demand for blood flow. Heart failure may be considered as the condition in which an abnormality of cardiac function is responsible for the inability of the heart to pump blood at a rate commensurate with the requirements of the metabolizing tissues, or can do so only at an abnormally elevated filling pressure. There are many specific disease processes that can lead to heart failure. Typically, these processes result in dilation of the left ventricular chamber.
• The process of ventricular dilation may be the result of chronic volume overload or may result from a specific damage to the myocardium. In a normal heart that is exposed to long-term increased cardiac output requirements, for example, that of an athlete, there is an adaptive process of slight ventricular dilation and muscle hypertrophy. In this way, the heart compensates for the increased cardiac output requirements. With damage to the myocardium, or chronic overload, however, there are increased requirements put on the contracting myocardium to such a level that this compensated state is never achieved and the heart continues to dilate.
• One condition that is likely to reduce the blood pumping efficiency of the heart muscle is ventricular dilation. As the chamber becomes enlarged, the internal surface area of the chamber increases rapidly. Blood flowing within the heart applies pressure to the internal surface of the heart chamber and because the blood applies pressure inside the heart chamber across an increased surface area, the force which must be produced by the heart in order to pump blood also increases. In many cases, the cardiac disease responsible for the ventricular dilation also limits the ability of the heart muscle to produce the increased force required to efficiently pump blood, which further compounds the problem.
• In many cases, the dilation of the heart chamber becomes progressively worse and the blood pumping efficiency of the heart muscle progressively declines. As this situation worsens, the location area of compromised myocardium may bulge out as the heart contracts, further decreasing the heart's ability to move blood forward. When local wall motion moves in this way it is said to be dyskinetic. The dyskinetic portion of the myocardium may stretch and eventually form an aneurismic bulge.
• There is no cure for heart failure, but it can be treated. The primary goals of treatment are to relieve symptoms and prevent worsening of the condition. Symptoms may be relieved by removing excess fluid from the body, improving blood flow and increasing delivery of oxygen to the body tissues. Medical treatment usually comprises lifestyle changes and medications. For example, diuretics have been used to reduce extra cellular fluid which accumulates in congestive heart failure patients, thereby increasing the preloaded condition of the heart. Nitrates, arteriolar vasodilators and angiotensin converting enzyme (ACE) inhibitors have been used to treat heart failure through the reduction of cardiac workload by reducing afterload. Inotropes function to increase cardiac output by increasing the force and speed of cardiac muscle contraction. These drug therapies offer some beneficial effects, but do not stop the progression of the disease.
• With respect to the situation of a dilated left ventricle or aneurism bulge, a variety of surgical studies have demonstrated some clinical success of ventricular remodeling and treatment of the dilation of the infarcted ventricle. One such remodeling procedure is referred to as the Batista Procedure. In the Batista Procedure, a small portion of the enlarged lower left ventricle chamber of the heart is removed to reduce the size of the left ventricle towards normal. Typically, the Bastista procedure involves the surgeon locating the left anterior descending coronary artery and making two small cuts down and outward to remove a wedge of the left ventricle. The remaining edges of the left ventricle are sewn together, returning the chamber to near its normal size. The incision is closed and the surgery is completed.
• A variation of the Batista Procedure, referred to as the Dor Procedure, involves a lengthwise incision in the left ventricle along an area damaged by a myocardial infarction. The undamaged areas of the ventricle are sutured back together, eliminating the affected area. If the damaged area is too large, a patch may be used to cover the damaged area. However, in each of the Batista and Dor procedures, restoration of normal ventricular shape is a complex surgical procedure and very invasive for the patient. Furthermore, these procedures are not applicable to those patients that are not candidates for such invasive surgery.
SUMMARY OF THE INVENTION
• Preferred methods of the present invention permit remodeling, tissue joining or tying of the left ventricle using a catheter-based percutaneous approach, which is far less traumatic to the patient than the Batista and Dor procedures. In addition, the methods and preferred devices disclosed herein may be adapted for use in remodeling soft tissue of a patient other than the left ventricle.
• A preferred method of remodeling a ventricle of a heart includes introducing a distal portion of at least one catheter through the aorta into the ventricle. The method also includes utilizing the at least one catheter to urge tissue portions on a same side of the ventricle towards each other and to secure the tissue portions such that the volume of the ventricle is reduced.
• Another preferred method of decreasing the volume of a ventricle of a heart includes providing an implant in contact with a wall of the ventricle at a contact location internal to the exterior surface of the heart and urging adjacent tissue portions located on a same side of the ventricle towards each other by applying force to the wall with the implant at the internal contact location.
• Still another preferred method of reducing the volume of a ventricle of a heart includes gathering tissue by folding a pair of adjacent tissue portions of a wall of the ventricle and repeating the folding to provide a plurality of tissue folds. The gathering comprises securing the plurality of tissue folds to retain the folded portions in close proximity by advancing at least one implant through the interior of the ventricle and securing the implant to a wall of the ventricle.
• A preferred embodiment is a cardiac treatment apparatus including a catheter having a catheter body configured to be introduced into a heart chamber through vasculature. The catheter includes a suture passage and a suture passing through the passage. The suture has an end portion. A tissue penetration member is movably mounted within the catheter body such that the penetration member enters an interior surface of a wall of the heart at a first location and exits the interior surface at a second location spaced from the first location. The penetration member is adapted to deliver the suture through the tissue between the locations, whereby application of tension to end portions of the suture draws the tissue locations towards each other.
• Another preferred embodiment is a cardiac treatment apparatus including a catheter having a catheter body configured to be introduced into a heart chamber through vasculature. The catheter includes a clip having end portions. The clip is movably mounted in the catheter body such that one end portion enters an interior surface of a wall of the heart to introduce at least a substantial portion of the clip into the wall. An intermediate portion of the clip is embedded in the wall and the end portions are resiliently biased to move relative to each other such that the movement of the end portions draws tissue portions towards each other.
• Yet another preferred embodiment is a cardiac treatment apparatus including a catheter having a catheter body configured to be introduced into a heart chamber through vasculature. The catheter includes a tissue anchor having a plurality of legs attached to a base. The legs are configured to pass through an interior surface of a wall of the heart and anchor the legs of the tissue anchor to the wall. The anchored legs have a first position upon the anchoring and are subsequently movable to a second position. The movement of the legs to the second position draws portions of tissue towards each other. The catheter also includes a retaining member for retaining the anchored legs in the second position when the catheter body is removed from the heart.
BRIEF DESCRIPTION OF THE DRAWINGS
• These and other features, aspects and advantages of the present tissue remodeling devices and methods are described in greater detail below with reference to drawings of several preferred embodiments, which are intended to illustrate but not to limit the present invention. The drawings contain 40 figures.
• FIG. 1 is a perspective view of a system for remodeling a left ventricle of a heart. The illustrated system includes certain features, aspects and advantages of a first embodiment. The remodeling system includes a catheter having a pair of coaxial catheter bodies.
• FIG. 2 is an enlarged view of a distal end of the catheter ofFIG. 1. The distal end of the catheter carries an inflatable balloon.
• FIG. 3 is a cross-sectional view of the distal end of the catheter ofFIG. 1, with the balloon illustrated in an inflated condition.
• FIG. 4 is a partial cross-sectional view of the catheter ofFIG. 1 illustrating a tissue remodeling clip that is positioned within a distal end of the inner catheter body.
• FIG. 5ais a side view of the catheter in a position wherein a distal end of the inner, tissue-penetrating catheter body is extended from the outer, guide catheter body.FIG. 5bis an end view of the tissue-penetrating catheter ofFIG. 5aas viewed in the direction of the arrow5bofFIG. 5a.
• FIGS. 6a-care several views of a first embodiment of the tissue remodeling clip illustrating several positions of the clip.FIG. 6ais a view of the clip in a relaxed position.FIG. 6bis a view of the clip in a biased position and, in particular, a substantially straightened position that may occur when the clip is docked within the catheter.FIG. 6cis a view of the clip implanted within soft tissue in a tissue remodeling position.
• FIGS. 7a-dare several views of a modification of the clip ofFIG. 6, wherein the ends of the clip include pledgets.FIG. 7ais a view of the clip in a relaxed position.FIG. 7bis a view of the clip in a straightened position with its end pledgets in an expanded orientation.FIG. 7cis a view of the clip in a straightened position and its end pledgets in a collapsed position.FIG. 7dis a view of the clip implanted within soft tissue in a tissue remodeling position.
• FIGS. 8a-care several views of yet another modification of the clip ofFIG. 6 in several positions.FIG. 8ais a view of the clip in a relaxed position.FIG. 8bis a view of the clip in a straightened position.FIG. 8cis a view of the clip implanted in soft tissue in a tissue remodeling position.
• FIG. 9 is a schematic illustration of the system being used to remodel a left ventricle of a patient's heart and being introduced into the patient's vasculature through the femoral artery.
• FIG. 10 is a cross-sectional view of the patient's heart with the catheter within the left ventricle and the balloon in an inflated position.
• FIG. 11 consists of several views illustrating several steps of a preferred method of using the catheter-based system ofFIG. 1.FIG. 11ais a cross-sectional view of the patient's heart with the catheter in contact with a wall of the left ventricle and the tissue-penetrating catheter penetrating the wall of the left ventricle.FIG. 11bis an enlarged view of a distal end portion of catheter with the tissue-penetrating catheter being rotated about is longitudinal axis to create a generally helical passage within the wall of the left ventricle.FIG. 11cis an enlarged view of the heart with the clip implanted into the passage created by the tissue-penetrating catheter.FIG. 11dis an enlarged view of the heart with the clip in a tissue remodeling position.FIG. 11eis a view of the clip ofFIGS. 7a-dimplanted into the wall of the ventricle and in a tissue remodeling position.
• FIG. 12 is a cross-sectional view of the heart illustrating several tissue remodeling clips positioned within the left ventricle.
• FIG. 13 is perspective view of a modification of the tissue remodeling system ofFIG. 1 and includes a catheter configured to deploy a collapsible tissue anchor.
• FIG. 14 is a perspective view of a tissue anchor delivery catheter body of the system ofFIG. 13.
• FIG. 15 is a partial cross-sectional view of the tissue anchor delivery catheter ofFIG. 14.
• FIG. 16ais a perspective view of the collapsible tissue anchor in a collapsed position.FIG. 16bis a perspective view of the tissue anchor in a relaxed position.
• FIG. 17 includes several views of the tissue anchor being deployed from the anchor delivery catheter.FIG. 17ais an enlarged, partial cross-sectional view of the tissue anchor docked within a distal end of the delivery catheter.FIG. 17bis a view of the tissue anchor deployed from the delivery catheter and assuming a relaxed position.FIG. 17cis a view of a retaining member delivered onto the tissue anchor to retain the tissue anchor in a tissue remodeling position.
• FIG. 18 is a cross-sectional view of a heart with the catheter inserted into the left ventricle.
• FIG. 19 is a cross-sectional view of the heart ofFIG. 18 illustrating the tissue anchor deployed from a distal end of the delivery catheter.
• FIG. 20 is a cross-sectional view of the heart ofFIG. 18 illustrating the tissue anchor penetrating the wall of the left ventricle.
• FIG. 21 is a cross-sectional view of the heart ofFIG. 18 illustrating the retaining member retaining the tissue anchor in a tissue remodeling position.
• FIG. 22 is a cross-sectional view of the heart ofFIG. 18 illustrating the tissue anchor released from the catheter and remodeling the wall of the left ventricle.
• FIG. 23 is a cross-sectional view of yet another modification of the tissue remodeling system ofFIG. 1. The system ofFIG. 23 includes a catheter configured to deliver a suture into the wall of the left ventricle and including an access catheter body and a suture delivery catheter body.
• FIG. 24 is an enlarged view of a distal end of the catheter ofFIG. 23.
• FIG. 25 is a cross-sectional view of the catheter ofFIG. 23 taken along the view line25-25 ofFIG. 23.
• FIG. 26 is a perspective view of the guide catheter ofFIG. 23 having the suture delivery catheter replaced by a clip delivery catheter that is configured to deliver a retaining clip.
• FIG. 27 is a cross-sectional view of a distal end portion of the clip delivery catheter ofFIG. 26.
• FIG. 28ais a perspective view of the clip removed from the delivery catheter and illustrated in a biased open position.FIG. 28bis a perspective view of the clip ofFIG. 28ain a relaxed position.
• FIG. 29 is a perspective view of the access catheter ofFIG. 23 and a knot pusher which may be used to push a knot in the suture from an exposed end of the suture through the catheter to a position behind the retaining clip.
• FIG. 30 is a perspective view of the access catheter ofFIG. 23 with the suture delivery catheter replaced by a suture cutting catheter.
• FIGS. 31a-care several views of a distal end portion of the suture cutting catheter ofFIG. 30 indicated by theview line31 ofFIG. 30.FIG. 31ais a cross-sectional view of a distal end portion of the suture cutting catheter.FIG. 31bis an end view of the suture cutting catheter.FIG. 31cis a cross-sectional view of the suture cutting catheter taken alongview line31c-31cofFIG. 31a.
• FIG. 32 is a schematic illustration of the tissue remodeling system ofFIGS. 23-31 being introduced into a patient to remodel the left ventricle of the patient's heart by accessing the patient's vasculature through the femoral artery.
• FIG. 33ais a cross-sectional view of the patient's heart illustrating the system delivering a suture through a wall of the left ventricle.FIG. 33bis an enlarged view of the distal end of the suture delivering catheter.
• FIG. 34ais a cross-sectional view of the patient's heart illustrating the suture delivered through the wall of the left ventricle and the catheter released from the wall of the heart.FIG. 34bis an enlarged view of the catheter ofFIG. 34a.
• FIG. 35 is a cross-sectional view of the patient's heart illustrating the suture delivery catheter delivering another suture to the ventricle wall.
• FIG. 36 is a cross-sectional view of the patient's heart illustrating the suture delivery catheter delivering yet another suture to the ventricle wall.
• FIG. 37 is a cross-sectional view of the patient's heart illustrating multiple sutures implanted in the ventricle wall with both free ends of the sutures extending through the access catheter.
• FIG. 38 is a cross-sectional view of the patient's heart illustrating the clip delivery catheter ofFIG. 26 delivering a retaining clip onto the sutures.
• FIG. 39 is a cross-sectional view of the patient's heart illustrating the retaining clip gathering the sutures to draw tissues portion of the ventricle toward one another and reducing the volume of the ventricle.
• FIG. 40 is a cross-sectional view of the patient's heart illustrating the gathered sutures and retaining clip secured by knots in the sutures behind the retaining clip. The ends of the sutures are cut behind the knots, preferably by a device such as the suture cutting catheter ofFIG. 30.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• Preferred embodiments and methods of the present tissue remodeling system permit remodeling, tissue joining, or tying of soft tissue and, in certain preferred arrangements, permit a remodeling of the left ventricle of a heart to reduce the volume of the ventricle. Preferably, the preferred embodiments permit soft tissue remodeling while avoiding the disadvantages of more invasive procedures and the complications that may occur as a result of such procedures. The preferred embodiments and methods may also permit tissue remodeling in patients that are otherwise unable to undergo conventional surgical procedures, such as open heart surgery. Preferred embodiments of the present system permit the duplication of the results of surgical procedures in reducing the volume of the left ventricle by a percutaneous transvascular technique using catheter-based devices. In addition, the preferred embodiments and method disclosed herein may be modified or adapted for use in the remodeling of soft tissue other than the left ventricle of a patient's heart.
• FIGS. 1-8 illustrate a first preferred embodiment of a tissue remodeling system, generally referred to by thereference numeral50. The illustratedsystem50 includes acatheter assembly52, which preferably includes multiple catheters, or catheter bodies. For simplicity, both thecatheter assembly52 and individual catheter bodies may be referred to by the term “catheter.” Preferably, thecatheter52 is sized, shaped and otherwise configured to be movable within a patient's vasculature to a desired remodeling site from a desired insertion site, such as the femoral artery, for example.
• Thus, thecatheter52 may be constructed from a variety of suitable materials using a variety of suitable fabrication techniques, such as those commonly known and used in constructing catheters for medical use. For example, thecatheter52, and other catheters discussed herein, may be constructed from polyethylene, polyurethane, silicone or polytetraflouroethylene, or other suitable materials by any suitable process. The illustratedcatheter52 includes a pair of coaxial catheter bodies. Theouter catheter body54 is referred to as a guide catheter, or access catheter, herein. The illustratedaccess catheter54 may have an outer diameter of about 26F (French) and an inner (lumen) diameter of about 22F. However, other suitable dimensions may be selected to suit an individual application of thecatheter54.
• Theinner catheter56 is movable within theaccess catheter54 and is referred to as a tissue-penetrating catheter herein. Theinner catheter56, in the illustrated arrangement, preferably has an outer diameter of about 18F and an inner (lumen) diameter of about 13F. However, other dimensions may be selected to suit a desired application of thecatheter56.
• In the illustrated arrangement, theaccess catheter54 is configured to be steerable to permit theaccess catheter54 to be guided through vasculature to a desired site. Preferably, an anchoringring58 is embedded within a distal end54aof theaccess catheter54. A deflection wire60 preferably is connected to and extends from theanchor ring58 within a wall of thecatheter54 to a proximal end of thecatheter54 where it is connected to acontrol knob62. Thus, thecontrol knob62 permits a user to selectively move the deflection wire60 relative to thecatheter54 to deflect a distal end54aof theaccess catheter54. Deflection of the distal end54aof theaccess catheter54 assists a user to routing thecatheter54 through the vasculature of a patient in a desired path. Alternatively, other suitable steering arrangements or positioning methods of theaccess catheter54 may be employed. In one arrangement, theaccess catheter54 may be configured to slide over a previously placed guidewire (not shown).
• Preferably, the distal end54aof theaccess catheter54 is configured to be atraumatic to the patient and, in particular, to the tissue at or near the remodeling site. In the illustrated arrangement, the distal tip54aof theaccess catheter54 carries an inflatable,annular balloon64. Preferably, theballoon64 is normally carried by theaccess catheter54 in an uninflated condition so as not to interfere with the passage of thecatheter54 through a patient's vasculature. Once in place within the left ventricle, theballoon64 may be inflated to contact the ventricle wall, help stabilize the distal end of theaccess catheter54 and inhibit a distal tip54aof theaccess catheter54 from damaging tissue. Preferably, theballoon64, in an inflated condition, extends beyond an end surface of the distal end54ato inhibit the distal end surface from contacting the wall of the heart. Theballoon64 may be constructed from a suitable, material and mounted to theaccess catheter54 by any suitable technique.
• Aninflation passage66 is defined within a wall of theaccess catheter54 and communicates with an interior space of theballoon64. A proximal end of theinflation passage66 extends from a proximal end54bof theaccess catheter54, preferably on a handle defined by the proximal end54band near the steeringknob62. Thus, theinflation passage66 may be connected to a suitablefluid supply source68, which is configured to supply a pressurized fluid to theballoon64 through theinflation passage66. In the illustrated arrangement, the source offluid68 is a standard syringe that is connected to theinflation passage66 preferably by suitableplastic tubing70. Any type of suitable connector, such as a luer lock for example, may be used to interconnect thetubing70 with theaccess catheter54 and the source offluid68. If desired, apressure indicator72 may be provided within the system to provide an indication of the fluid pressure within the balloon.
• As described above, the tissue-penetratingcatheter56 is movable within theaccess catheter54. Preferably, the tissue-penetratingcatheter56 is movable to a stowed position within theaccess catheter54 wherein, preferably, the entiredistal end56aof the tissue-penetratingcatheter56 is positioned within the distal end54aof theaccess catheter54. Preferably, the tissue-penetratingcatheter56 is also movable to a protruding position relative to theaccess catheter54 wherein thedistal end56aof the tissue-penetratingcatheter56 is exposed from the distal end54aof theaccess catheter54. Preferably, aproximal end56bof the tissue-penetratingcatheter56 defines a handle configured to permit a user to move the tissue-penetratingcatheter56 between its stowed and protruding positions.
• In the illustrated arrangement, thedistal end56aof the tissue-penetratingcatheter56 is configured to create a passage within soft tissue of a patient and deliver an implant, or atissue remodeling clip74, into the passage. With reference toFIGS. 1 and 4, preferably the tissue-penetratingcatheter56 carries thetissue remodeling clip74 within itsdistal end56a. In the illustrated arrangement, apush rod76 is positioned within the tissue-penetratingcatheter56 and proximal of theclip74. The distal end76bof thepush rod76 preferably defines a contact surface configured to permit thepush rod76 to apply a force to theclip74. A proximal end76bof thepush rod76 terminates in a handle, which permits a user of thesystem50 to deploy theclip74 from the tissue-penetratingcatheter56 by advancing thepush rod76 within the tissue-penetratingcatheter56.
• Desirably, thedistal end56aof the tissue-penetratingcatheter56 assumes a nonlinear shape in a relaxed position. That is, preferably, when no restraining force is present on thedistal end56aof the tissue-penetratingcatheter56, thedistal end56amoves into a nonlinear orientation. Preferably, in a relaxed position, thedistal end56ais arcuate or curved and, more preferably, assumes a generally helical shape. The helix angle, radius and length of thedistal end56amay be altered to suit the properties of the tissue that to be remodeled. Preferably, at least thedistal end56aof the tissue-penetratingcatheter56 preferably is constructed from a suitable shape memory material that is configured to have a desired shape in its relaxed position, such as a nickel titanium alloy (NiTi), for example.
• With such an arrangement, when the tissue-penetratingcatheter56 is in its stowed position, theaccess catheter54 constrains thedistal end56ainto a generally straightened orientation, or a shape that generally matches the shape of the distal end54aof theaccess catheter54 at a given time. However, when the tissue-penetratingcatheter56 is moved to its protruding position, thedistal end56atends to move toward its predefined relaxed shape. In use, outside forces may inhibit thedistal end56aof the tissue-penetratingcatheter56 from reaching its full relaxed orientation, such as forces imposed by the tissue in which thedistal end56ais penetrating. Preferably, the relaxed shape of thedistal end56aof the tissue-penetratingcatheter56 is configured such that the shape assumed by thedistal end56awill be generally as desired in the presence of anticipated restraining forces, such as those originating from soft tissue of a patient, for example. Furthermore, although a helical shape is preferred, in other applications other shapes may be desirable, as will be appreciated by one of skill in the art. Preferably, the tip of thedistal end56aof the tissue-penetrating catheter is angled relative to a longitudinal axis of thecatheter56 to permit thedistal end56aof the tissue-penetratingcatheter56 to pierce soft tissue. Other suitable tip shapes that would permit thecatheter56 to pierce or penetrate soft tissue may also be used.
• Preferably, thetissue remodeling clip74 is configured to be movable between a nonlinear, relaxed position and a biased, or straightened position. Thus, theclip74 preferably is constructed from a shape memory material, such as NiTi. When stowed within the tissue-penetratingcatheter56, preferably theclip74 is biased into a generally linear orientation or a shape that generally matches the shape of thedistal end56aof the tissue-penetratingcatheter56. When deployed from the tissue-penetratingcatheter56, theclip74 moves toward its relaxed position wherein, preferably, afirst end74aof theclip74 is resiliently biased to move toward asecond end74b, as illustrated inFIG. 6a. In the illustrated arrangement, theclip74 in a relaxed position assumes a generally circular shape. However, theclip74 may be configured to assume other suitable shapes in its relaxed position.
• The illustratedclip74 may have a diameter from between about 0.005 inches to about 0.05 inches. The circular loop defined by theclip74 in its relaxed position may have a diameter from about 0.06 inches to about 0.5 inches. A length of theclip74 may be from about 0.5 inches to about 2 inches. These dimensions are presently preferred for aclip74 configured to remodel the left ventricle of a patient's heart. In other applications, other dimensions may be desirable. Theclip74 may be shaped by winding a work piece on a mandrel and then exposing the work piece to a heat cycle of about 500 degrees centigrade for a period of between about 10 minutes to about 60 minutes, depending on the strength, spring rate and oxide layer desired. Furthermore, other suitable methods of shaping theclip74 may also be used.
• As illustrated inFIG. 6c, when implanted into soft tissue T, theclip74 moves toward its relaxed position such that thefirst end74aapplies a force to the tissue T at a first location and thesecond end74bapplies a force to the tissue T at a second location spaced from the first location to remodel the soft tissue T. As discussed above with respect to thedistal end56aof the tissue-penetratingcatheter56, in use theclip74 may not move completely to its relaxed position due to restraining forces, such as forces imposed by the soft tissue. Thus, the tissue remodeling position of theclip74 may fall somewhere between its straightened position and its relaxed position. Furthermore, the ends74a,74bof theclip74 may remain embedded within the soft tissue T. However, preferably theclip74 does not protrude through an external surface of the tissue wall (the non-entry side of the wall). That is, when theclip74 is implanted within a ventricle of a heart, preferably, theclip74 enters the heart wall from a location internal the ventricle and does not pass through an outer surface of the heart wall.
• FIGS. 7a-7dillustrate a modification of thetissue remodeling clip74 and is generally referred to by thereference numeral80. Theclip80 includes a pledget at each of its first and second ends80a,80b. Thepledgets82 preferably are relatively thin, circular members which have a diameter substantially larger than a diameter of theclip80 when thepledgets82 are in an expanded position (FIGS. 7a,7band7d). Therefore, thepledgets82 inhibit theends80a,80bof theclip80, once passed completely through soft tissue T, from pulling back through the surface of the tissue T. Thus, the ends80a,80bof theclip80 preferably remain exposed from the tissue T. Preferably, thepledgets82 are collapsible to permit theclip80 to be initially implanted into the tissue T, as illustrated inFIG. 7c.
• In a preferred embodiment, thepledgets82 may be constructed from a piece of polymer material, such as Dacron, that is cut into a circular shape with a central aperture. Thepledgets82 may be placed over theends80a,80bof theclip80 and theends80a,80benlarged to retain thepledgets82 on theclip80. The enlarged ends may be formed by resistance spot welding, laser welding, or other suitable methods. Further, the enlarged ends may be created by additional members that are separate from, and secured to, theclip80.
• Another modification of theclip74 ofFIG. 6 is illustrated inFIGS. 8a-8cand is referred to by thereference numeral90. Theclip90 ofFIGS. 8a-8cincludes a plurality ofbarbs92 on each of the first and second ends90a,90b. Thebarbs92 are configured to penetrate tissue to inhibit movement of theclip90 relative to the tissue. The barbs92 (and ends90a,90b) may be embedded in the tissue T when theclip90 is implanted, as shown inFIG. 8c, or, alternatively, may be exposed from the tissue T. Thebarbs92 may be created by a laser cutting technique, electrical discharge machining (EDM), mechanical cutting techniques, or other suitable processes. In addition, other suitable stabilizing members or arrangements to inhibit movement of theclips74,80,90 relative to the tissue into which they are implanted may also be used. Furthermore, although the illustrated clips74,80,90 are circular in cross-sectional shape, other suitable shapes may also be used, such as a rectangular or elliptical cross-section, for example.
• FIGS. 9-12 illustrate a preferred method for utilizing thesystem50 ofFIGS. 1-8 to remodel soft tissue of a patient P and, preferably, to remodel the left ventricle of the patient's P heart H. In a preferred application of the method illustrated inFIGS. 9-12, access to the left ventricle of the heart H is achieved through the patient's vasculature V from an insertion site in the femoral artery F. If desired, a sleeve (not shown) may be inserted into the femoral artery F to provide access for thecatheter52. Alternatively, other methods of accessing the left ventricle, preferably using a percutaneous approach, may also be used.
• With reference toFIG. 10, thecatheter52 is illustrated accessing the left ventricle LV of the patient's heart through the aorta A. Thecatheter52 may be routed to the left ventricle LV by any suitable method. For example, as described above, thecatheter52 may be steerable to permit a user to navigate the patient's P vasculature using a suitable imaging technique. For example, preferably, the method is performed by a cardiologist in a cathlab setting using a transesophageal echocardiogram (TEE) or angiographic fluoroscopy imaging technique to accomplish each of the steps described herein that take place within the patient P. In addition, other imaging techniques may also be used. If desired, a guide wire (not shown) may be routed to the left ventricle LV and thecatheter52 may be introduced to the left ventricle LV over the guide wire.
• As will be appreciated by one of skill in the art, a human heart H includes a right atrium RA, a left atrium LA, a right ventricle RV and a left ventricle LV. The tricuspid valve TV separates the right atrium from the right ventricle and the pulmonary valve PV separates the right ventricle from the pulmonary artery PA. The mitral valve MV separates the left atrium LA from the left ventricle LV and they aortic valve AV separates the left ventricle LV from the aorta A.
• As illustrated inFIG. 10, in the preferred method, theballoon64 is inflated so that thecatheter assembly52, andaccess catheter54 in particular, may be held against the wall of the left ventricle LV without causing damage thereto. Thus, preferably theballoon64 supports a distal tip of theaccess catheter54 at least slightly spaced from the wall of the left ventricle LV. Theballoon64 may also contact the wall of the left ventricle LV adjacent the desired remodeling site to inhibit the distal end54aof theaccess catheter54 from moving once it is positioned.
• With reference toFIG. 11a, once theaccess catheter54 is guided to a desired position within the left ventricle LV, thetissue penetrating catheter56 may be moved from its stowed position within theaccess catheter54 towards its protruding position such that the tissue-penetratingcatheter56 creates a passage within the wall of the left ventricle LV. Preferably, the tissue-penetratingcatheter56 creates a passage that has a shape generally corresponding to the relaxed shape of thedistal end56aof the tissue-penetratingcatheter56. If desired, one or both of theaccess catheter54 and the tissue-penetratingcatheter56 may be rotated to assist the tissue-penetratingcatheter56 in creating a passage within the wall of the left ventricle, as illustrated by thearrows94 inFIG. 11b.
• With reference toFIG. 11c, once the passage has been created within the wall of the left ventricle LV, thepush rod76 may be used to hold theclip74 in position while permitting the tissue-penetratingcatheter56 to be withdrawn from the passage and into theaccess catheter54, thus leaving theclip74 in place within the passage in the wall of the left ventricle LV. Alternatively, the tissue-penetratingcatheter56 may be withdrawn from the passage, along with theclip74, and thepush rod76 used to subsequently deploy theclip74 into the preformed passage. The preferred method of deploying theclip74 may depend on individual user preference, the shape of theclip74 or the properties of the soft tissue T, among other considerations.
• As illustrated inFIG. 11c, with the distal end of theaccess catheter54 andballoon64 pressed against the wall of the left ventricle LV, theclip74 is inhibited from moving substantially toward its relaxed position. With reference toFIG. 11d, once theaccess catheter54 is pulled away from the wall of the left ventricle LV, thetissue remodeling clip74 may move substantially toward its relaxed position, thus bringing theends74a,74bof theclip74 toward one another to draw the portions of the ventricle wall associated with each end74a,74btoward one another. Accordingly, the implantation of theclip74 thereby remodels and preferably reduces the volume of the left ventricle LV. In the illustrated arrangement, theclip74 is implanted in the free wall of the left ventricle LV. That is, theclip74 is implanted into tissue defining a wall of the ventricle other than the septal wall. However, in some applications it may be desirable to remodel the septal wall, such as when performing a septal defect repair. Thus, the present systems disclosed herein may be used to remodel the septal wall, or may be appropriately modified to remodel the septal wall, if so desired.
• InFIGS. 11a-11d, theimplantable clip74 is illustrated. However, other embodiments of the clip, such as theclips80 and90, may be implanted in a similar manner. With reference toFIG. 1e, theclip80 is illustrated as implanted in the wall of the left ventricle LV. In theclip80, preferably the ends80aand80bprotrude from an inner surface of the wall of the left ventricle and thepledgets82 contact the inner surface of the wall of the ventricle LV to inhibit theends80a,80bfrom withdrawing into the wall of the left ventricle.
• FIG. 12 illustrates a plurality of remodeling clips80 implanted within the wall of the left ventricle to remodel the left ventricle LV and, preferably, reduce the volume of the left ventricle LV. In some applications, only oneclip74,80,90 may be desired and, in other applications, a plurality ofclips74,80,90 may be used depending on what level of remodeling, or reduction in volume, is desired. In a preferred method, enough clips74,80,90 are implanted to substantially completely fold away the akinetic portion of the ventricle tissue. However, it is contemplated that one of skill in the art will be able to determine a suitable number ofclips74,80,90 to be implanted depending on a particular application, the level of remodeling desired, the properties of theclip74,80,90, and the properties of the soft tissue, among other considerations.
• FIGS. 13-17 illustrate a second embodiment of a tissue remodeling system, generally referred to by thereference numeral100. Preferably, thesystem100 is a catheter-based tissue remodeling system that is configured to facilitate the remodeling of soft tissue of a patient at a desired site that is accessed through the patient's vasculature. The illustratedsystem100 is configured to remodel a patient's heart and, preferably, reduce the volume of the left ventricle of the heart. However, as described above, the systems and methods disclosed herein may be used to otherwise manipulate, gather, fold, tie or join soft tissue, such as to achieve a closing of a tissue cavity, for example.
• Thesystem100 includes acatheter assembly102 including a plurality of coaxial catheter bodies. In the illustrated arrangement, thecatheter assembly102 includes a guide catheter, oraccess catheter104. Adelivery catheter106 is movable within a lumen of theaccess catheter104. Preferably, aguide wire108 is movable within a lumen of thedelivery catheter106. Thecatheter102 is configured to deliver an implant, orcollapsible tissue anchor110, to a desired tissue remodeling site, such as the left ventricle of the heart in the illustrated arrangement, for example.
• Preferably, theaccess catheter104 is substantially similar to theaccess catheter54 of thesystem50 ofFIGS. 1-8. Theaccess catheter104 includes a distal end104aconfigured to be introduced into the left ventricle of a patient's heart and a proximal end104bdefining a handle. Theaccess catheter104 may be of any suitable size, shape, and length to extend from the desired remodeling site to a site external the patient through a suitable route. For example, the illustratedcatheter102 preferably is sized to extend from a left ventricle of a patient's heart to an external site adjacent the patient's femoral artery. Preferably, theaccess catheter104 may have an outer diameter of about 26F and an inner (lumen) diameter of about 23F. However, other suitable dimensions may be used to suit a desired application. Furthermore, thecatheter102 may be constructed of any suitable material for use in a medical catheter application, as described above.
• Thedelivery catheter106 is configured to be axially movable within theaccess catheter104. Thedelivery catheter106 includes adistal end106a, which is configured to support thetissue anchor110, and a proximal end106bdefining a handle. Thedelivery catheter106 may be constructed from any suitable material, as described above, and preferably has an outer diameter of about 0.25 inches and an inner (lumen) diameter of about 0.125 inches. However, the dimensions may be adjusted to suit a desired application.
• Theguide wire108 preferably is configured to be deliverable through the vasculature of a patient to the left ventricle as an individual component to permit theaccess catheter104 anddelivery catheter106 to be introduced into the left ventricle by being passed over the previously placedguide wire108. Preferably, theguide wire108 includes a tip111 at its distal end108athat is configured to be atraumatic to tissue that it comes into contact with. Desirably, theguide wire108 also includes a proximal end108b, which defines a handle or other structure that permits a user to manipulate theguide wire108.
• With reference toFIGS. 14 and 15, desirably, thedelivery catheter106 includes adocking tip112 at itsdistal end106a. Preferably, thetip112 defines an outer surface that has a reduced diameter relative to a diameter of the outer surface of the remainder of thedelivery catheter106. Thedocking tip112 is sized and shaped to support a proximal end of thetissue anchor110 thereon. Thus, preferably, an outer diameter of thetissue anchor110 is generally equal to an outer diameter of thedelivery catheter106 such that when thetissue anchor110 is positioned on thetip112, the transition between thecatheter106 and thetissue anchor110 is relatively seamless. Although thecollapsible tissue anchor110 is illustrated as surrounding thedocking tip112 in the illustrated arrangement, other suitable arrangements to interconnect thetissue anchor110 and thedelivery catheter106 may also be employed.
• Preferably, thedelivery catheter106 includes aretention mechanism114 that is configured to secure thetissue anchor110 to thedistal end106aof thedelivery catheter106 and selectively release thetissue anchor110 from thedelivery catheter106. In the illustrated arrangement, aretention wire116 is slidably received within apassage118 defined by a wall of thedelivery catheter106. Adistal end116aof theretention wire116 is configured to extend radially outwardly relative to thecatheter106, from thepassage118, into anaperture120 of thetissue anchor110. A proximal end116bof theretention wire116 includes a handle, or other suitable structure, which permits a user to retract theretention wire116 within thepassage118 to release thetissue anchor110 from thedelivery catheter106.
• Alternatively, other suitable arrangements to retain and selectively release thetissue anchor110 may also be employed. In some arrangements, for example, thetissue anchor110 andcatheter106 may cooperate through a snap-fit arrangement in which an interference surface of thecatheter106 contacts an interference surface of thetissue anchor110 to inhibit theanchor110 from unintentionally becoming separated from thecatheter106. In such an arrangement, once thetissue anchor110 is implanted within soft tissue, theanchor110 may be automatically separated from thecatheter106 when a pulling force is applied to thecatheter106, as thetissue anchor110 preferably will remain in place within the tissue.
• FIGS. 16aand16billustrate thetissue anchor110 removed from thedelivery catheter106. Preferably, thetissue anchor110 includes abase portion130 and a plurality oflegs132 which extend from thebase portion130. Desirably, thetissue anchor110 includes between about 2 and 8legs132 and, preferably, between about 3 to 5legs132. The illustratedtissue anchor110 includes threelegs132. However, other suitable numbers oflegs132 may be provided in accordance with the requirements an individual application.
• Preferably, thetissue anchor110 is a hollow member having a relatively thin wall thickness dimension. Preferably, thetissue anchor110 is constructed of a metal material and, more preferably, from a shape memory material, such as NiTi, for example. Desirably, thebase130 is generally cylindrical in shape and thelegs132, preferably, are unitary with thebase130 and extend from the wall thereof. The base130 may have an outer diameter of about 0.25 inches and an inside diameter of about 0.188 inches, for ananchor110 configured to be implanted into a left ventricle of a patient's heart. However, the dimensions may be altered to achieve desired properties of theanchor110 to suit an individual application, such as the closure of a cavity or hole, for example. Thelegs132 may be created by cutting away material from an initial work piece, or sleeve, using a laser cutting method, or other suitable fabrication method.
• Preferably, thelegs132 are movable, or flexible, relative to the base130 between a relaxed position, wherein thelegs132 extend radially outward from thebase130, to a collapsed position, or tissue-remodeling position, wherein thelegs132 are biased inwardly from their relaxed position. Preferably, in the collapsed position, thelegs132 are generally aligned with the wall of thebase130. However, in some applications, thelegs132 may extend radially outward from thebase130, or radially inward from thebase130, in the tissue-remodeling position.
• With reference toFIG. 17c, preferably, aretention member134 is configured to retain thelegs132 in the tissue remodeling position. In the illustrated arrangement, theretention member134 is in the form of a sleeve which slides over an outer surface of thelegs132, as is described in greater detail below. However, other suitable retention mechanisms may also be employed.
• Each of thelegs132 preferably includes a pointedtissue piercing end136 to permit thelegs132 to penetrate soft tissue of a patient, such as the wall of the left ventricle of the patient's heart. In addition, preferably thelegs132 include one ormore barbs138, which are configured to permit thelegs132 to enter soft tissue, in a first direction, and inhibit thelegs132 from being removed from the soft tissue in the opposite direction. Thus, once thelegs132 have penetrated the soft tissue, preferably, thetissue anchor110 remains embedded in the tissue.
• Desirably, thetissue anchor110 is configured to inhibit theretention member134 from inadvertently becoming dislodged from thetissue anchor110. In the illustrated arrangement, thebase130 includes a plurality of pawls, ortabs140, which are configured to permit theretention member134 to move toward the distal end of thetissue anchor110 and inhibit theretention member134 from moving away from the distal end, toward the proximal end of thetissue anchor110 past thetabs140. Desirably, thetabs140 are generally semi-circular in shape and comprise an outwardly-bent portion of the material of the base130 portion of thetissue anchor110. Thus, thetabs140 bend inwardly, into general alignment with thebase130, to permit theretention sleeve134 to pass over. Once theretention sleeve134 has passed over thetab140, it returns to its outwardly-bent position to interfere with an attempt of theretention sleeve134 in moving back over thetab140, as illustrated inFIG. 17c. In some arrangements, tabs may also be defined by thelegs132. Furthermore, in an alternative arrangement, thetabs140 may be defined by members that are separate from, and attached to, thetissue anchor110.
• In the illustrated arrangement, thebase130 includes several rows oftabs140 wherein each row includesmultiple tabs140 arranged around the circumference of thebase130. In the illustrated arrangement, thetissue anchor110 includes three rows oftabs140, wherein each row includes threetabs140 equally spaced about a circumference of thebase130. However, other suitable arrangements to permit unidirectional movement of theretention member134 may also be used.
• FIGS. 17athrough17cillustrate thetissue anchor110 in several states of deployment from thecatheter assembly102. With reference toFIG. 17a, desirably thedelivery catheter106 is positioned within theaccess catheter104 such that thetissue anchor110 is substantially entirely enclosed within theaccess catheter104 and constrained thereby into a collapsed position.
• With reference toFIG. 17b, when thetissue anchor110 is deployed from theaccess catheter104, thelegs132 are permitted to move toward their relaxed position. It should be noted that the radial expansion of thelegs132 toward their relaxed position may be influenced by the distance of which thetissue anchor110 is exposed from theaccess catheter104. In some applications,legs132 of thetissue anchor110 may be completely deployed from theaccess catheter104 prior to thelegs132 contacting soft tissue. Thus, in the absence of any other restraining force, thelegs132 would be in their fully relaxed position when contact with the soft tissue is made. In other applications, however, thelegs132 may be retained partially within theaccess catheter104 so that thelegs132 are constrained from moving to their fully relaxed position. Accordingly, the diameter of a circle defined by the legs132 (or the distance between thelegs132 and an axis of the catheter104) may be altered as desired prior to contact with the soft tissue. In addition, other methods of facilitating thetissue anchor110 in grabbing a portion of soft tissue of a desired size or shape may also be used.
• With reference toFIG. 17c, the retention member, or lockingsleeve134, may be slid over thedelivery catheter106 and on to thetissue anchor110 by apusher catheter142. Theretention sleeve134 may be pushed a sufficient distance on to thetissue anchor110 to move thelegs132 toward a tissue remodeling position to achieve a desired amount of remodeling. Desirably, thetabs140 inhibit theretention sleeve134 from becoming disengaged with thetissue anchor110. Alternatively, thelegs132 may be moved toward a tissue-remodeling position by another member and theretention sleeve134 may be used simply to retain thelegs132 in the desired tissue-remodeling position.
• FIGS. 18-22 illustrate a preferred method of remodeling soft tissue of a patient using thesystem100 ofFIGS. 13-17. The illustrated method utilizes thesystem100 to remodel the left ventricle of a patient's heart and, preferably, to reduce the volume of the left ventricle. Desirably, access to the left ventricle is gained through the patient's vasculature beginning at an insertion site in the femoral artery F, as shown inFIG. 9. However, other methods of gaining access to the left ventricle may also be used.
• With reference toFIG. 18, theguide wire108 may be advanced through the patient's vasculature, from the femoral artery F, to enter the left ventricle LV through the aorta A using a suitable imaging technique, as described above. Theguide wire108 is positioned preferably such that its distal end108acontacts a portion of the wall of the left ventricle LV where remodeling is desired. Subsequently, thedelivery catheter106 andaccess catheter104 may be advanced over theguide wire108, either individually or together, until the distal end of each approaches the wall of the left ventricle LV. Preferably, the distal end of theaccess catheter104 anddelivery catheter106 are spaced from the wall of the left ventricle LV as illustrated inFIG. 18.
• With reference toFIG. 19, thedelivery catheter106 may be advanced relative to theaccess catheter104 andguide wire108 such that thetissue anchor110 is deployed therefrom. Once thetissue anchor110 is at least partially deployed from theaccess catheter104, thelegs132 may move toward their relaxed, or radially outward position. As described above, the distance that thetissue anchor110 is deployed from theaccess catheter104, which preferably applies a restraining force to thelegs132, influences a distance that thelegs132 may expand from a center axis of thecatheter104. Such a technique may be used to determine the amount of tissue grasped by thelegs132 of thetissue anchor110. In the illustrated arrangement, thetissue anchor110 is shown completely deployed from theaccess catheter104.
• With reference toFIG. 20, thedelivery catheter106 and, if desired, theaccess catheter104, may be moved relative to theguide wire108 toward the wall of the left ventricle LV until thetips136 of thelegs132 of thetissue anchor110 penetrate the wall of the left ventricle LV. Desirably, with the illustratedtissue anchor110, thelegs132 do not penetrate an outer surface of the heart H. However, in some arrangements, it may be desirable that thelegs132 pass completely through the wall of the heart H. Once thelegs132 have been entered the wall of the left ventricle LV, thebarbs138 preferably inhibit thelegs132 from being removed therefrom.
• With reference toFIG. 21, theaccess catheter104 may be removed from thedelivery catheter106 to permit thelocking clip134 to be positioned over thedelivery catheter106. Thepusher catheter142 may then be used to move thelocking ring134 to the distal end of the delivery catheter and over thetissue anchor110 to move thelegs132 toward their tissue-remodeling position. As described above, the lockingsleeve134 may be moved on to the tissue anchor110 a sufficient distance to move thelegs132 until a desired level of remodeling is accomplished. Thepusher catheter142 may then be removed and thetabs140 of thetissue anchor110 inhibit thelocking ring134 from becoming disengaged with thetissue anchor110 and thereby retain thetissue anchor110 in its tissue remodeling position. Alternatively, theaccess catheter104 may be adapted to carry and deploy the lockingsleeve134 to eliminate the need for aseparate pusher catheter142.
• With reference toFIG. 22, thetissue anchor110 is shown in its tissue remodeling orientation configured to reduce the volume of the left ventricle LV of the patient's heart H. Once the retainingsleeve134 is positioned as desired on thetissue anchor110, thepusher catheter142 andguide wire108 may be removed, leaving thetissue anchor110 implanted in place in the left ventricle LV. If desired, more than onetissue anchor110 may be deployed using a similar method to create a plurality of tissue folds, depending on the level of remodeling or volume-reduction desired. The multiple tissue anchors110 may be arranged relative to one another in any suitable orientation to achieve a desired degree or shape of tissue remodeling. For example, the tissue anchors110 may be arranged along a line generally passing through the tissue area that is desired to be remodeled.
• FIGS. 23-31 illustrate another embodiment of a tissue remodeling system generally referred to by thereference numeral150. Thetissue remodeling system150 is configured to deliver a suture to soft tissue of a patient to facilitate remodeling of the soft tissue of a patient. Preferably, a plurality of sutures are delivered to accomplish the tissue remodeling. The illustratedsystem150 is configured to remodel of the left ventricle of a patient's heart and, preferably, to reduce the volume of the left ventricle using a percutaneous approach through the patient's vasculature. Preferably, the vasculature is accessed through an insertion site in the patient's femoral artery. In addition, other remodeling, tissue joining or tying can be accomplished with the illustratedsystem150 or modifications thereof.
• The illustratedsystem150 includes acatheter assembly152 including a guide catheter, oraccess catheter154, and asuture delivery catheter156, which is axially slidable within theaccess catheter154. Thecatheter assembly152 is configured to be insertable into a patient's vasculature and, preferably, directed to the patient's left ventricle to facilitate a remodeling of the ventricle.
• Theaccess catheter154 preferably includes adistal end154aconfigured to be insertable into the patient's left ventricle. The proximal end154bof theaccess catheter154 is configured to remain outside of the patient and, preferably, defines a handle. Theaccess catheter154 may be constructed from any suitable material, as described above, and may be of any suitable size and shape. In the illustrated embodiment, theaccess catheter154 has an outer diameter of up to about 26F and an inner (lumen) diameter of about 23F. In addition, if desired, theaccess catheter154 may be steerable, as described in connection with thecatheter54 ofFIGS. 1-3.
• Thesuture delivery catheter156 includes adistal end portion156athat is configured to deliver an end of a suture through the soft tissue of a patient and, preferably, permit the end of the suture to be removed from the patient along with thecatheter156. A proximal end156bof thesuture delivery catheter156 is configured to be exposed from theaccess catheter154 and, preferably, defines a handle. Thesuture delivery catheter156 may be constructed from any suitable material, as described above, and may be of any suitable size or shape. In the illustrated arrangement, thecatheter156 may have an outer diameter of about 22F. However, thecatheter156 may be constructed with other suitable dimensions as well.
• Thedistal end156aof thesuture delivery catheter156 preferably defines a cavity, orrecess158, which is configured to receive a portion of the wall of the patient's left ventricle. In one arrangement, therecess158 may be generally semi-cylindrical in shape. Once the soft tissue is positioned within therecess158, thesuture delivery catheter156 is configured to permit an end of the suture to be passed through the tissue. Preferably, therecess158 is sized such that the suture passes through an inner surface of the wall of tissue, without passing through the outer surface of the wall. To assist in positioning tissue within therecess158, preferably, avacuum passage160 communicates with therecess158 at one end and extends through a wall of thesuture delivery catheter156 to the proximal end156b. Avacuum source162 preferably is connected to thevacuum passage160 by a suitable connection.
• Preferably, thecatheter152 also includes astabilizer mechanism164 that is configured to assist in stabilizing thecatheter152 within the left ventricle while the suture is being passed through the wall of the left ventricle. Thestabilizer mechanism164 may also be useful to assist in positioning the distal end152aof thecatheter152. The illustratedstabilizer mechanism164 includes astabilizer wire166, a portion of which is exposed in the form of a loop near adistal end156aof thesuture delivery catheter156. Adistal end166aof thestabilizer wire166 preferably is embedded in adistal end156aof thesuture delivery catheter156. From the distal end,166a, thestabilizer wire166 extends in a loop external to thesuture delivery catheter156 until it passes into an opening168 in thesuture delivery catheter156 and extends to a proximal end of thesuture delivery catheter156 through apassage170.
• A proximal end of thestabilizer wire166 defines a handle. Thus, a user may push the handle of the proximal end166bof thestabilizer wire166 to enlarge the size of the loop of thestabilizer wire166 at thedistal end156aof thesuture delivery catheter156. Conversely, if the handle of the proximal end166bof thestabilizer wire166 is pulled away from the proximal end156bof thesuture delivery catheter156, the size of the loop is reduced. Thestabilizer wire166 may be manipulated to vary size of the exposed loop to press against an inner surface of the left ventricle to maintain thedistal end156aof thesuture delivery catheter156 in contact with a wall of the left ventricle. Furthermore, preferably, thestabilizer wire166 may be retracted completely, or nearly completely, within thesuture delivery catheter156 so as not to interfere with movement of thecatheter156 within theaccess catheter154.
• Preferably, thesystem150 also includes asuture delivery device172. Thesuture delivery device172 preferably includes apassage174 defined by the body of thesuture delivery catheter156. Preferably, adistal end174aof thesuture passage174 communicates with therecess158 and a proximal end174bof thesuture passage174 opens from a proximal end of thesuture delivery catheter156.
• Apush rod176 extends through thesuture passage174. A distal end176aof thepush rod176 carries a releasable tissue penetration member, orneedle178, which is configured to carry one end of asuture180. A proximal end176bof thepush rod176 defines a handle that is external of thesuture delivery catheter156. Thus, thesuture passage174 preferably is sized and shaped to accommodate both asuture180 and thepush rod176. In the illustrated arrangement, thesuture passage174 may have a diameter of about 0.065 inches to accommodate apush rod176 having a diameter of about 0.045 inches (17 Gauge). However, thepassage174 and pushrod176 may have other suitable dimensions to suit a desired application.
• In the illustrated arrangement, theneedle178 and thepush rod176 are connectable by a snap-fit arrangement, which is configured to retain theneedle178 on thepush rod176, once assembled, and permit theneedle178 to be selectively removed from thepush rod176 upon application of a sufficient removal force. Furthermore, an end of thesuture180 may be coupled to theneedle178 in any suitable manner. In the illustrated embodiment, the suture passes through anaperture181 in the push rod176 (FIG. 24) before being secured to theneedle178.
• Thesuture delivery catheter156 preferably also defines aneedle trap182 on an end of therecess158 opposite thesuture passage174. Desirably, theneedle trap182 is aligned with thesuture passage174 such that theneedle178 will enter thetrap182 once it has passed through therecess158. In the illustrated arrangement, theneed trap182 is an elongate passage configured to receive theneedle178 and inhibit theneedle178 from being released from thetrap182. Theneedle trap182 may be of any suitable construction to permit theneedle178 to enter thetrap182 in a first direction and inhibit theneedle178 from being removed. In one arrangement, thetrap182 may comprise one or more oriented ribs, barbs or surface features that exhibit slight resistance to entry of theneedle178, but exhibit significantly greater resistance to the removal of theneedle178. In addition, other suitable arrangements may also be used.
• Thus, once positioned within thetrap182, theneedle178 remains in thetrap182 and is disconnected from thepush rod176 as thepush rod176 is retracted from thesuture delivery catheter156. Thus, theneedle178 andsuture180 may be pushed through the tissue occupying therecess158, entering the tissue at a first location and exiting the tissue at a section location, until theneedle178 is received within thetrap182. Thepush rod176 may then be retracted from thesuture delivery catheter156 leaving theneedle178 within thetrap182 and thesuture180 extending through the tissue. Thesuture180 may be pulled through the tissue along with thesuture delivery catheter156 as thesuture delivery catheter156 is removed from the left ventricle, as is described in greater detail below. As a result, both ends of thesuture180 will be external the patient, with the suture passing through a section of tissue. Applying tension to both ends of thesuture180 will tend to draw the tissue portions associated with the entry and exit locations of thesuture180 towards one another.
• With reference toFIGS. 26-28, thetissue remodeling system150 also includes acatheter190 configured to deliver aretaining clip192, which is configured to retain at least onesuture180, and preferably a plurality ofsutures180, in a gathered position, as is described in greater detail below. The retainingclip delivery catheter190 preferably includes anouter catheter body194 and aninner catheter body196. Theouter catheter194 andinner catheter196 are coaxial with one another and configured to cooperate to deliver the retainingclip192 through theaccess catheter154. In the illustrated arrangement, theouter catheter194 may have an outer diameter of about 22F, with a lumen of about 17F. Theinner catheter196 may have an outer diameter of about 12 to 14F, with a lumen of about 10F. Other suitable dimensions may be used to suit an individual application.
• With reference toFIG. 27, preferably, the retainingclip192 is supported on a distal end portion196aof theinner catheter196. Adistal end portion194aof theouter catheter194 is positioned adjacent the retainingclip192. Theouter catheter194 is movable relative to theinner catheter196 to selectively push theretaining clip194 off of the distal end196aof theinner catheter196.
• With reference toFIGS. 28aand28b, desirably the retainingclip192 is formed from a shape memory material, such as NiTi, for example, such that theclip192 is moveable from a biased opened position, such as when supported on theinner catheter196, to a relaxed position, wherein the retainingclip192 coils over on itself, as illustrated inFIG. 28b. When in its relaxed position, the retainingclip192 is configured to retain one ormore sutures180 in a gathered orientation, as is described in greater detail below.
• With reference toFIG. 29, preferably, both thesuture delivery catheter156 and the retainingclip delivery catheter190 may be removed from theaccess catheter154. Aknot pusher200 may be used to push aknot202 from external a proximal end154bof theaccess catheter154 to external adistal end154aof theaccess catheter154 and, preferably, against the retainingclip192. Thus, one ormore knots202 may be used to inhibit, or prevent, the retainingclip192 from moving relative to thesutures180 to advantageously retain thesutures180 in a gathered orientation. Theknot pusher200 preferably is of a conventional construction comprising an elongate body of stainless steel having distal tip formed into a loop, as will be appreciated by one of skill in the art. Other suitable methods or devices to move aknot202 along thesutures180 or otherwise inhibit undesired movement of the retainingclip192 may also be used.
• Thetissue remodeling system150 preferably also includes asuture cutting device210. Thesuture cutter assembly210 preferably includes acatheter212 having a distal end212aand a proximal end212b. Desirably, the proximal end212bdefines a handle. Thecatheter212 preferably includes adistal end section214 and aproximal end section216. Preferably, theproximal end216 includes asemi-cylindrical passage218 and asuture passage220. Apush rod222 extends through thepassage218 and, preferably, is also semi-cylindrical in shape to generally match the shape of thepassage218. Adistal end222aof thepush rod222 preferably includes a cuttingsurface223 and a proximal end222bof the push rod defines a handle.
• Thedistal end section214 preferably also includes asemi-cylindrical passage226 that is closed by aplug228. Further, thedistal end section214 preferably includes a suture passage230. In the illustrated arrangement, thedistal end section214 defines a workingspace232 between thepassage226 and suture passage230 of thedistal end section214 and thepassage218 andsuture passage220 of theproximal end section216. Desirably, thedistal end section214 is oriented such that thesuture passage220 and the suture passage230 are directly opposite one another. Thesuture180 may be passed through thepassages220 and230 so that thesuture180 will pass through the workingspace232 past the cuttingsurface223 of thepush rod222. Thepush rod222 may be advanced to cut the suture between the cuttingsurface223 of thedistal end222aand theplug228. Alternatively, thedistal end section214 may be rotatable relative to theproximal section216 such that thesuture passages220 and230 may be selectively aligned, the suture passed through thepassages220 and230, and thedistal end section214 rotated relative to theproximal section216 such that thesuture passages220 and230 are opposite one another so that the suture may be cut. In addition, other suitable devices or methods may also be used to cut the one ormore sutures180, if desired.
• With reference toFIGS. 32-40, a preferred method of remodeling tissue with thesystem150 ofFIGS. 23-31 is illustrated. As described above, the preferred method is utilized to reduce a volume of the left ventricle LV of the heart H of a patient P. With reference toFIG. 32, desirably, thesystem150 is configured to be introduced into the vasculature V of the patient P at a desired site. In the illustrated arrangement, thecatheter152 is introduced through the femoral artery F of the patient P and is guided to the left ventricle LV.
• With additional reference toFIGS. 33aand33b, thesuture delivery catheter156 is positioned within the left ventricle LV so that the suture may be passed through a desired site of the wall of the left ventricle LV. Thesuture delivery catheter156 may be positioned by steering one or both of theaccess catheter154 andsuture delivery catheter156. In addition, the stabilizingwire166 may be used to assist in positioning thesuture delivery catheter156 and retaining thesuture delivery catheter156 in a desired position within the left ventricle LV.
• Once positioned as desired, thevacuum source162 may be activated to draw tissue within the recess158 (FIG. 24) of thesuture delivery catheter156. Thepush rod166 may then be advanced to push theneedle178 through the tissue occupying therecess158. Thepush rod166 preferably is advanced until theneedle178 enters thetrap182 whereby thesuture180 is passed through the tissue within therecess158.
• With referenceFIGS. 34aand34b, the stabilizingwire166 may be retracted and thevacuum source162 deactivated. Thesuture delivery catheter156 may be withdrawn thereby pulling thesuture180 through the tissue and removing the end of thesuture180 along with thesuture delivery catheter156. Thus, once thesuture delivery catheter156 is completely removed from the patient's vasculature, both ends of thesuture180 will be external the patient with thesuture180 passing through a section of the tissue of the left ventricle LV, entering the tissue at a first location and exiting the tissue at a second location spaced from the first location.
• With reference toFIGS. 35 and 36, preferablyadditional sutures180 are positioned within the left ventricle in desired positions relative to theinitial suture180. Preferably, themultiple sutures180 are positioned such that, when drawn together, the tissue of the left ventricle will be drawn together along a desired suturing line around the diseased portion of the ventricle, which will reduce the volume of the ventricle. However, in some arrangements, a desired level of remodeling, tying or tissue joining may be accomplished with only onesuture180.
• With references toFIGS. 37-39, once a desired number ofsutures180 are placed within the left ventricle LV, the retainingclip delivery catheter190 is advanced over thesutures180 and within theaccess catheter154 until a distal end of the retainingclip delivery catheter190 is within the left ventricle LV. The retainingclip delivery catheter190 is advanced until thesutures180 are drawn together to reduce the volume of the left ventricle LV, preferably much like the closing of a pursestring suture. When thesutures180 are drawn together to a sufficient degree, theouter catheter194 may be advanced relative to theinner catheter196 such that the retainingclip192 is deployed therefrom, preferably substantially as described above with reference toFIG. 27.
• FIG. 40 illustrates the gathered sutures retained by the retainingclip192 such that the volume of the left ventricle LV is reduced. Preferably, the left ventricle LV is reduced to a volume that approximates the normal size of the ventricle prior to the onset of heart disease, or that results in an acceptable level of performance. In one arrangement, the dyskinetic portion of the left ventricle LV is essentially eliminated from defining the working chamber of the ventricle LV. If the dyskinetic portion of the ventricle LV is large enough, the plurality ofsutures180, in a drawn together orientation, create two chambers within the ventricle: a working chamber WC and a dormant chamber DC. Preferably, thesutures180 draw the wall of the ventricle together to an extent that the chambers WC and DC are substantially isolated from one another. That is, although some minor amount of fluid communication may exist between the chambers WC and DC, the dormant chamber DC does not effectively contribute to the working volume of the ventricle LV.
• As illustrated, preferably, a plurality ofknots202 are created within thesutures180 and advanced to a position behind theretainer clip192 to retain thesutures180 in a drawn together position. Preferably, theknots202 are advanced from external the patient P to behind theretainer clip192 by a knot pusher, such as theknot pusher200 described in relation toFIG. 29. However, other suitable methods or devices for creating knots, or otherwise retaining theretainer clip192 in a desired position, may also be used. In addition, the ends of thesutures180 are cut, preferably using a device substantially as described with respect toFIGS. 30 and 31. However, other suitable methods or devices for cutting thesutures180 may also be used.
• Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In particular, while the present tissue remodeling systems and methods have been described in the context of particularly preferred embodiments, the skilled artisan will appreciate, in view of the present disclosure, that certain advantages, features and aspects of the system may be realized in a variety of other applications, many of which have been noted above. Additionally, it is contemplated that various aspects and features of the invention described can be practiced separately, combined together, or substituted for one another, and that a variety of combination and subcombinations of the features and aspects can be made and still fall within the scope of the invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims.

Claims (21)

1. A cardiac treatment apparatus, comprising:

a catheter having a catheter body configured to be introduced into a heart chamber through vasculature, said catheter comprising a clip having end portions, said clip movably mounted in said catheter body such that one end portion enters an interior surface of a wall of said heart to introduce at least a substantial portion of said clip into said wall, wherein an intermediate portion of said clip is embedded in said wall and said end portions are resiliently biased to move relative to each other such that said movement of said end portions draws tissue portions towards each other.

2. The apparatus ofclaim 1, wherein a distal end of said catheter is configured to move towards a non-linear relaxed shape in the absence of a constraining force.

3. The apparatus ofclaim 2, wherein said non-linear relaxed shape comprises a helical shape.

4. The apparatus ofclaim 1, wherein said clip comprises a unitary member defining said first end, said second end and said intermediate portion.

5. The apparatus ofclaim 4, wherein said clip additionally comprises stabilizing components at each of said first and second ends to inhibit movement of said clip relative to the ventricle wall.

6. The apparatus ofclaim 1, wherein said clip is carried within a lumen of said delivery catheter.

7. An assembly for remodeling a heart ventricle, comprising:

an access catheter defining a lumen, said access catheter configured to be deliverable from an access site through vasculature to the heart ventricle;

a delivery catheter configured to be movable within said lumen of said access catheter, a distal end of said delivery catheter defining a tissue-penetrating tip;

a tissue-remodeling clip carried by said delivery catheter, said clip having a first end, a second end and an intermediate portion connecting said first and second ends;

wherein said delivery catheter may be advanced relative to said access catheter such that said tissue-penetrating tip of said delivery catheter penetrates a wall of the heart and said delivery catheter creates a channel within the wall, said tissue-remodeling clip being deployable from said delivery catheter and into said channel wherein said first and second ends of said clip are resiliently biased towards one another to remodel the wall of the heart ventricle.

8. The assembly ofclaim 7, wherein a distal end of said delivery catheter is configured to move towards a non-linear relaxed shape when advanced from said access catheter.

9. The assembly ofclaim 8, wherein said non-linear relaxed shape comprises an arcuate shape.

10. The assembly ofclaim 8, wherein said non-linear relaxed shape comprises a helical shape.

11. The assembly ofclaim 7, wherein said distal end of said delivery catheter is sized and shaped such that said channel passes through a portion of the ventricle wall without passing through an exterior surface of the ventricle wall.

12. The assembly ofclaim 7, wherein said clip comprises a unitary member defining said first end, said second end and said intermediate portion.

13. The assembly ofclaim 12, wherein said unitary member is constructed from a shape memory alloy.

14. The assembly ofclaim 12, wherein said clip additionally comprises stabilizing components at each of said first and second ends to inhibit movement of said clip relative to the ventricle wall.

15. The assembly ofclaim 14, wherein said stabilizing components comprise pledgets.

16. The assembly ofclaim 14, wherein said stabilizing components comprise barbs.

17. The assembly ofclaim 7, wherein said intermediate portion of said clip has a generally circular cross-sectional shape.

18. The assembly ofclaim 7, wherein a distal end of said access catheter carries an inflatable, annular balloon.

19. The assembly ofclaim 18, wherein said balloon is configured to contact an interior surface of the ventricle wall and space a distal end surface of said access catheter from the interior surface.

20. The assembly ofclaim 7, wherein said clip is carried within a lumen of said delivery catheter.

21. The assembly ofclaim 7, additionally comprising a push rod configured to be movable within said lumen of said delivery catheter, a distal end of said push rod configured to contact clip such that said push rod may be advanced relative to said delivery catheter to deploy said clip.

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