Patent Application
20070005127
Exemplary embodiments of the present invention relate generally to a medical implant for inserting into body tissue and a method of delivering and using such a medical implant. Exemplary embodiments of the present invention also may relate to an implant configured to provide flow communication between blood-containing coronary structures, such as, for example, between a heart chamber and a coronary vessel or between two coronary vessels.
An implant for insertion into body tissue may have various uses, such as providing flow communication between two body parts, delivering drugs into a body part, or serving as a sensor, controller, or monitoring device, for example. Without limiting the scope of the present invention, the following paragraphs describe an exemplary use of an implant, such as a stent or conduit, for example, to treat blockages in coronary vessels. The examples discussed below do not constitute a limitation on the scope and applications of the present invention.
Coronary artery disease may be treated with several approaches. Coronary arteries, as well as other coronary vessels, frequently become clogged with plaque which, at the very least, can reduce blood and oxygen flow to the heart muscle (myocardium). The plaque also may impair the efficiency of a heart's pumping action and lead to heart attack or death. In some cases, these coronary arteries can be unblocked through noninvasive techniques, such as, for example, performing balloon angioplasty or stenting a vessel to provide a blood passageway. In more difficult cases, performing a surgical bypass of the blocked vessel may be necessary.
One conventional treatment for a clogged coronary artery is a coronary bypass operation wherein one or more venous segments are inserted between the aorta and the coronary artery. The inserted venous segments or transplants bypass the clogged portion of the coronary artery and thus provide a free and unobstructed flow communication of blood between the coronary artery and the heart. Such conventional coronary artery bypass surgery, however, may be expensive, time-consuming, and traumatic to a patient. Hospital stay subsequent to surgery and convalescence generally is prolonged. Furthermore, many patients may not be suitable surgical candidates due to other concomitant illnesses.
An alternative to coronary artery bypass, angioplasty, and vessel stenting includes providing a flow passage in the myocardial wall between the left ventricle and the coronary artery. The passage may be provided at a point downstream of the blockage. In this technique, a portion of the blood from the left ventricle flows directly through the passage in the myocardial wall and into the artery downstream of the blockage. A variation of this technique includes placing a stent in the heart wall to provide the blood flow passage between the left ventricle and coronary artery.
A variation of this technique includes forming a passage in the myocardial wall between the left ventricle and a coronary vein proximate an occluded coronary artery. The vein may be used to supply oxygenated blood to the heart. A conduit, for example a stent, may be inserted in the passage, and the vein may include a blocking device proximate the passage to restrict blood flow toward the coronary sinus.
As yet a further alternative, the passage may be formed in the myocardial wall between two coronary vessels, such as between a coronary vein and a coronary artery, for example.
A problem that may be encountered when using a stent or other type of implant is migration. Migration of the stent after its insertion may lead to the protrusion of the stent beyond the heart wall, for example, either into the left ventricle or into the blood flow lumen of the coronary vessel, either the coronary artery or coronary vein, for example. Migration may create a risk that the stent may not be positioned so as to establish an unobstructed passageway for blood flow. For example, the stent may extend too far into the lumen of the coronary vessel, blocking blood flow therethrough, or may be displaced from the heart chamber or coronary vessel, hindering blood flow through the myocardial passageway. Migration may also allow portions of the myocardial tissue that surround a passageway to advance toward the passageway and cause the passageway to contract, especially when the myocardial tissue is not sufficiently supported by the stent. The contraction of the passageway may reduce or entirely block blood flow through the stent, thereby rendering the stent less effective in providing an unblocked channel of blood flow to the coronary vessel. In addition to the reduction or complete blockage of blood flow, migration of the stent from a designated location potentially will interfere with other structures in the heart and may pose serious risk of embolization.
Another problem associated with these techniques involves delivery of a myocardial implant. In particular, when using a percutaneous technique, implantation and positioning may prove difficult. For instance, during percutaneous delivery, positioning using X-ray images, fluoroscopy, or the like may not be sufficiently accurate, which may result in the implant being placed too high or too low with respect to the vessel. Moreover, delivery techniques and tools can be relatively complex. In addition, when delivering implants with self-deploying seating mechanisms, such seating mechanisms may be difficult to orient and angle, and there also may be limited feedback regarding positioning of the implant to the physician, for example when using fluoroscopy.
Some advantages and purposes of the invention will be set forth in part in the description which follows, and may be obvious from the description, or may be learned by practice of the invention. It should be understood that skilled artisans may practice the invention without having one or more features of any of the objects, aspects, or embodiments described herein. In addition, such features are exemplary and at least some of them are set forth in the detailed description which follows.
Exemplary embodiments of the implant and delivery tool designs may permit percutaneous delivery and proper positioning without great complexity. For example, in exemplary embodiments, the implant may have a relatively small profile so as to facilitate delivery and implantation. Moreover, in exemplary embodiments, the design of delivery tools, such as delivery catheters, for example, to deliver the implant may be simplified.
An exemplary aspect of the invention includes a device for treating a heart. The device may comprise a stent having at least a portion thereof that does not extend completely around the circumference of the stent so as to form a first stent section and a second stent section that are articulatable relative to each other. In an exemplary embodiment, the first stent section may form a myocardial section configured to be positioned in a heart wall between a heart chamber and a coronary vessel. The second stent section may form a vessel section configured to be positioned in a coronary vessel.
Another exemplary aspect of the invention includes a method of treating a heart. The method may include providing a stent comprising a plurality of stent cells, wherein at least part of a stent cell does not extend completely around the circumference of the stent so as to permit a first stent section and a second stent section to articulate relative to each other The method may further include delivering the stent to a location proximate to a heart wall, inserting the first section in a heart wall between a coronary vessel and a chamber of the heart, and inserting the second section in the coronary vessel.
In another exemplary aspect, the invention includes a delivery system. The delivery system may comprise a catheter having a proximal end portion and a distal end portion. The distal end portion may comprise a first lumen and a second lumen substantially adjacent the first lumen. The first lumen and the second lumen may form a branched configuration so as to permit independent movement of the first lumen and the second lumen.
Yet a further exemplary embodiment of the invention includes a method of making an implant. The method may include providing a stent comprising a plurality of stent cells and forming at least one stent cell such that a circumferential portion of at least part of the stent cell is missing so as to form a first stent section and a second stent section that are configured to articulate relative to each other.
Yet another exemplary aspect of the invention includes a device for treating a heart comprising a stent comprising a first stent section, a second stent section, and a third stent section connecting the first and second stent sections. Each of the first stent section and the second stent section may include at least one stent cell, and the connecting section may include a strut of the stent (e.g., a segment of the stent) extending around only a portion of a circumference of the stent so that the first and second stent sections articulate relative to each other. In an exemplary aspect, a stent cell may include one of a plurality of repeating annular segments of the stent. In a further exemplary aspect, the connecting section may have a length less than a length of a stent cell.
According to another exemplary aspect, the invention may include a device for treating a heart comprising a stent comprising a plurality of stent cells, wherein at least one stent cell is missing at least a circumferential portion thereof so as to permit a first stent section and a second stent section to articulate relative to each other.
According to an exemplary aspect, the implant may be in the form of a stent. The myocardial section of the implant may be inserted in the heart wall so as to place the heart chamber and coronary vessel in flow communication with each other. The myocardial section may be inserted in a heart wall between a left ventricle and either a coronary artery or a coronary vein, for example.
Another exemplary embodiment of the invention includes a device for treating a heart. The device includes a stent having a portion thereof that does not extend completely around the circumference of the stent so as to form a first stent section and a second stent section that articulate relative to each other.
In various embodiments, the invention may include one or more of the following aspects: the first stent section may include a myocardial section configured to be positioned in a heart wall between a coronary vessel and a chamber of the heart and the second stent section may include a vessel section configured to be positioned in the coronary vessel; the myocardial section may be configured to provide flow communication between the heart chamber and the coronary vessel when the stent is positioned in the heart wall; the myocardial section may be configured to be positioned in the heart wall between a left ventricle and one of a coronary artery and a coronary vein; a covering over at least a portion of the stent; the covering may include one of a polymer, a metal, and a tissue; the first section and the second section may be connected to each other via a hinged section; the portion of the stent that does not extend completely around the circumference of the stent may form the hinged section; the hinged section may have a length equal to approximately half of a length of a stent cell; the portion may extend from approximately 10 degrees to approximately 90 degrees around the circumference of the stent; the stent may be expandable; the vessel section may be configured to achieve a diameter approximately equal to a diameter of the vessel lumen when the vessel section is positioned in the coronary vessel; the device may be configured to be percutaneously delivered and implanted in the heart; and the device may be configured to be surgically delivered and implanted in the heart.
A further exemplary embodiment of the invention includes a method of treating a heart. The method includes providing a stent having a portion that does not extend completely around the circumference of the stent so as to form a first stent section and a second stent section that articulate relative to each other, delivering the stent to a location proximate to a heart wall, inserting the first stent section in a heart wall between a coronary vessel and a chamber of the heart, and inserting the second stent section in the coronary vessel.
In various embodiments, the invention may include one or more of the following aspects: forming a passageway in the heart wall between the coronary vessel and the heart chamber and inserting the first section into the passageway; flowing blood through the stent between the heart chamber and the coronary vessel after inserting the stent; delivering the stent may include delivering the stent to the location proximate to the heart wall via a catheter; inserting the first stent section may include inserting the first stent section in the heart wall between a left ventricle and one of a coronary artery and a coronary vein; expanding the stent; expanding the stent may include expanding the stent via a balloon; expanding the stent may include allowing the stent to self-expand; delivering the stent may include percutaneously delivering the stent; and delivering the stent may include delivering the stent through a lumen of the coronary vessel.
Still another exemplary embodiment of the invention includes a delivery system. The delivery system includes a catheter having a proximal end portion and a distal end portion. The distal end portion includes a first shaft defining a first lumen and a second shaft defining a second lumen, the second shaft being substantially adjacent the first shaft. The first shaft and the second shaft form a branched configuration so as to permit independent movement of at least portions of the first shaft and the second shaft.
In various embodiments, the invention may include one or more of the following aspects: a first balloon carried by the first shaft and a second balloon carried by the second shaft; the proximal end portion may include the first shaft and the second shaft connected to each other; the proximal end portion may include a third shaft defining a third lumen; the third lumen may be in flow communication with a first balloon carried by the first shaft and a second balloon carried by the second shaft; and a first guide wire configured to exit the first shaft and a second guidewire configured to exit the second shaft.
A still further exemplary embodiment of the invention includes a method of delivering an implant to a heart wall between a heart chamber and a coronary vessel. The method includes advancing a first shaft of a catheter into the heart wall, the first shaft carrying a first section of the implant, advancing a second shaft of the catheter into the coronary vessel, the second shaft carrying a second section of the implant, and positioning the implant such that the first section of the implant is placed in the heart wall and the second section of the implant is placed in the lumen of the coronary vessel.
In various embodiments, the invention may include one or more of the following aspects: inserting a second guidewire through a lumen of the coronary vessel and inserting a first guidewire through the lumen of the coronary vessel and into the heart wall; advancing the first shaft includes advancing the first shaft over the first guidewire and advancing the second shaft includes advancing the second shaft over the second guidewire; positioning the implant includes positioning the implant such that the implant places the heart chamber in flow communication with the lumen of the coronary vessel; expanding the first and second sections of the implant; expanding the first and second sections of the implant includes expanding the first section via a first balloon carried by the first shaft and expanding the second section via a second balloon carried by the second shaft; the first shaft may also carry the second section of the implant; carrying the implant on the catheter such that the first and second sections are folded relative to each other; the implant may be a stent; the heart chamber may be a left ventricle; the coronary vessel may be chosen from a coronary vein and a coronary artery; bending the first and second sections relative to each other during the positioning of the implant; the positioning may include positioning the second section such that a longitudinal axis of the second section is substantially parallel to a longitudinal axis of the lumen of the coronary vessel; at least one of the first shaft and the second shaft may be carrying a third section of the implant connected to one of the first section and the second section; positioning the implant such that the third section of the implant is placed in the lumen of the coronary vessel; the third section may not be connected to the first section; the third section may not be connected to the second section; carrying the implant on the catheter such that at least two of the first, second, and third sections are folded relative to each other; bending at least two of the first, second, and third sections relative to each other during the positioning of the implant; the positioning may include positioning the third section such that a longitudinal axis of the third section is substantially parallel to a longitudinal axis of the lumen of the coronary vessel.
Yet another exemplary embodiment of the invention includes a device for treating a heart. The device includes a stent comprising a first stent section, a second stent section, and a third stent section connecting the first and second stent sections. Each of the first stent section and the second stent section includes at least one stent cell. The connecting section includes at least one stent segment extending around only a portion of a circumference of the stent so that the first and second stent sections articulate relative to each other.
In various embodiments, the invention may include one or more of the following aspects: a stent cell may include one of a plurality of repeating annular segments of the stent; and the connecting section may have a length less than a length of a stent cell.
A yet further exemplary embodiment of the invention includes a device for treating a heart. The device includes a stent structure having a circumferential portion missing therefrom so as to form a first section of the stent structure and a second section of the stent structure that are configured to articulate relative to each other.
Another exemplary embodiment of the invention includes a device for treating a heart. The device includes a first stent section, a second stent section connected to the first stent section and configured to articulate relative to the first stent section, and a third stent section connected to the first stent section, unconnected to the second stent section, and configured to articulate relative to the first stent section. The first, second, and third stent sections may be configured to form a substantially T-shaped structure.
In various embodiments, the invention may include one or more of the following aspects: the first stent may be connected to the second stent section via a connector; the first and second stent sections may be configured to articulate about the connector; the third stent section may be connected to the first stent section via a connector; the first and third stent sections may be configured to articulate about the connector; the first stent section may be configured to be positioned in one of a coronary vessel and a heart wall between a coronary vessel and a heart chamber; the first stent section may be configured to be positioned in a heart wall between a coronary vessel and a heart chamber; the second and third stent sections may be configured to be positioned in the coronary vessel; the first and second stent sections may be configured to be positioned in a coronary vessel; and the third section may be configured to be positioned in a heart wall between the coronary vessel and a heart chamber.
A further exemplary embodiment of the invention includes a device for treating a heart. The device includes a first stent section having a lumen. The first stent section includes an open first end, an open second end, and a hole between the first and second ends. The device also includes a second stent section extending through the hole. The second stent section includes a first portion extending within the lumen of the first stent section and a second portion extending from the hole outside of the lumen.
In various embodiments, the first and second stent sections may form a substantially T-shaped structure.
Still another exemplary embodiment of the invention includes a device for treating a heart. The device includes a first stent section and a second stent section connected to, and configured to articulate relative to, each other, and a third stent section and a fourth stent section connected to, and configured to articulate relative to, each other. One of the third stent section and the fourth stent section is configured to be disposed within a lumen of one of the first stent section and the second stent section.
In various embodiments, a longitudinal axis of the one of the third stent section and the fourth stent section may be configured to be substantially parallel to a longitudinal axis of the one of the first stent section and the second stent section.
A still further exemplary embodiment of the invention includes a device for treating a heart. The device includes a first stent section and a second stent section connected to the first stent section via a connector and configured to articulate relative to the first stent section about the connector.
In various embodiments, the invention may include one or more of the following aspects: the connector may be at least one of a ring, a loop, a wire, a strip, a string, a cable, a suture, and a rope; each of the first stent section and the second stent section may include a U-shaped section; the connector may be disposed about the U-shaped section of each of the first stent section and the second stent section; each of the first stent section and the second stent section may include a hole; the connector may be disposed through the hole of each of the first stent section and the second stent section; the connector may be a notched region; the connector may be attached to at least one of the first stent section and the second stent section; and the connector may be at least two connectors.
Yet another exemplary embodiment of the invention includes a method of placing a first guidewire in a coronary vessel and a second guidewire in a heart wall. The method includes providing the first guidewire, the second guidewire, a puncture tool including a lumen and a side hole, and a guide tool including a guide, advancing the first guidewire through a puncture site and into the coronary vessel, advancing the guide tool through the puncture site and into the coronary vessel via the first guidewire, advancing the puncture tool through the guide, the coronary vessel, and the heart wall into a heart chamber, advancing the second guidewire through the heart wall and into the heart chamber via the guide tool, the side hole, and the lumen, and removing the puncture tool.
In various embodiments, the invention may include one or more of the following aspects: the guide tool may include a first section and a second section; each of the first and second sections may include the guide; advancing the guide tool may include advancing the second section through the puncture site and into the coronary vessel via the first guidewire until a portion of the first section is substantially flush with an outer surface of the coronary vessel; the guides on the first and second sections may be substantially aligned; the puncture tool may include a slit in communication with the lumen and the side hole; removing the puncture tool may include removing the puncture tool such that the second guidewire exits the lumen via the slit; the puncture tool may include markers on an outer surface; and determining a thickness of the heart wall via the markers.
A yet further exemplary embodiment of the invention includes a puncture tool configured to assist the advancement of a guidewire into a heart wall. The method includes an elongate body including a distal end configured to puncture tissue, the elongate body defining a lumen, a hole in a side of the elongate body, and a slit extending from the hole to the distal end.
In various embodiments, the invention may include one or more of the following aspects: markers on an outer surface of the elongate body and the markers may be configured to assist in determining a thickness of the heart wall.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention. Those embodiments, together with the following description, serve to explain certain principles and provide a further understanding of the invention. In the drawings,
Reference will now be made in detail to exemplary embodiments illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
In exemplary embodiments, the present invention provides a multi-section implant for implanting in a body part, for example, in body tissue. An implant inserted into body tissue may have various uses, such as, for example, providing flow communication between two body parts, delivering drugs into a body part, or serving as a sensor, controller, or monitoring device. Exemplary embodiments of the present invention provide a heart implant, such as a stent, for example, having a two-section hinged structure. In addition, exemplary embodiments of the present invention provide a method of delivering and inserting such a two-section implant into the heart and a method of treating the heart using the implant to deliver blood from a chamber of the heart to a coronary vessel. Although certain exemplary embodiments described below relate to a two-section implant, it is contemplated that such an implant may have more than two sections. The number of sections and the location of each section relative to other sections may depend, for example, on the application for which the implant is being used and other factors influencing the number and relative positioning of the sections.
A heart wall implant according to exemplary embodiments of the invention may provide a direct blood flow passageway between a chamber of a heart, such as the left ventricle, and any coronary vessel, such as a coronary vein or a coronary artery, including for example a left anterior descending coronary artery, or between two coronary vessels, such as between a coronary artery and a coronary vein, for example. The devices and methods also encompass the use of an implant for delivering drugs into a body part or for serving as a sensor, controller, or monitoring device within the body.
As shown in the exemplary embodiment of
Myocardial section 22 lies within a passage 30 in the myocardial wall between the posterior wall 32 of a coronary vessel CV (either a coronary artery or vein) to proximate the inner wall 36 of the left ventricle LV, potentially protruding into the heart chamber. Section 22 may lie in the heart wall MYO such that it is approximately flush with the floor (i.e., the posterior wall 32) of the coronary vessel CV. Myocardial section 22 may have a length in the range of approximately 10 mm to approximately 35 mm, for example, approximately 17 mm to approximately 28 mm, depending on the size of the patient's myocardium at the insertion site. That size may be determined by suitable measuring techniques, as described further below.
Vessel section 24 lies within the coronary vessel CV. Referring to
As used herein, the terms proximal and distal may refer to the direction that the delivery apparatus is introduced into the cardiovascular system as opposed to direction of blood flow. For example, in a percutaneous approach, a delivery apparatus would generally be introduced into the coronary vessels such that, whether it is introduced into the coronary artery via the coronary ostium or the coronary vein via the coronary sinus, the capillaries will be located distal to the delivery apparatus, regardless of the fact that the delivery apparatus may be advanced in the normal direction of flow in the coronary artery, and against the normal direction of flow in the coronary vein. Thus, the possibility of retrograde blood flow through the coronary vein, for example, as set forth in
These designations are preferences and are not absolute, however. One of ordinary skill in the art would realize that the implant, including two or more of the vessel section, the myocardial section, and the protection section may be placed in any configuration relative to the coronary vessel and/or heart wall. For example, there may be some situations where the vessel section is placed distal to the myocardial section (e.g., closer to the capillaries). In addition, in some embodiments, it may be more advantageous to describe proximal and distal in terms of direction of blood flow.
As discussed above, the coronary vessel CV may be a coronary vein or a coronary artery, for example. When the implant is placed so as to flow blood from a heart chamber to a coronary vein, thereby causing retroperfusion in the vein so as to “arterialize” the vein, the implant may be used in conjunction with a venous blocking device. Such a venous blocking device may be placed in the lumen of the coronary vein relative to the vessel portion of the implant so as to at least partially occlude flow through the vein in the normal antegrade direction (e.g., toward the coronary sinus), thereby permitting the blood flow through the implant to flow in a retrograde direction through the coronary vein (e.g., toward the capillaries).
As discussed above, negative effects may result if the myocardial section 22 protrudes into the coronary vessel CV or is recessed within the heart wall MYO. For example, if section 22 protrudes too far into the lumen of the coronary vessel CV, blood flow through the coronary vessel CV (especially in the case of a coronary artery), as well as blood flow exiting from section 22 may become blocked, reducing the blood flow within the vessel. On the other hand, if section 22 is recessed within the heart wall MYO such that a space remains between section 22 and the posterior wall 32 of the coronary vessel CV, the space may become occluded with heart tissue, thereby hindering or preventing blood flow through section 22 and into the coronary vessel CV.
In addition to being properly positioned, the implant should not migrate from its position. In certain applications, it may be desirable to cover the inside, outside, or both, of a heart wall implant with a covering, such as, for example, a polymer covering such as an expanded polytetrafluoroethylene (ePTFE), polyurethane, collagen, or polyester fabric, for example, a tissue covering, or a metal covering, such as metal foil, for example. Such covering may help prevent the myocardial tissue from extruding into the lumen of the implant when a mesh-type stent is used. But this covering may reduce the frictional force that holds the implant in place and allow the implant to move away from an installed, desired position. In the case of a heart wall implant, the continuous, repetitive heart pumping action and variations in the blood flow may cause the implant in a heart wall to migrate from its designated location toward a left ventricle or a coronary vessel, for example. Thus, the implant may be vulnerable to migration for various different reasons, such as migration along the axis of the passageway, for example. As explained above, the migration of the implant may create undesirable risks, including but not limited to, stasis, occlusion of the passageway provided by the implant, vessel occlusion, embolization, and interference with the functioning of other body components, such as heart structures, for example.
Further, it is desirable to provide a mechanism by which to properly position the implant upon implantation.
Embodiments of the present invention may eliminate the above-mentioned risks and problems associated with improper initial positioning and migration by providing a multi-piece hinged implant, such as that shown in
Additionally, a hinged implant, such as that illustrated in
The stent 20 in the exemplary embodiment of
In the example shown in
In the exemplary embodiment shown in
Myocardial section 42 of stent 40, only a portion of which is shown in
A stent according to embodiments of the invention may be elastic or have expandable and/or collapsible structures. The collapsed stent may facilitate the delivery of the implant into the heart wall MYO by providing a smaller structure during delivery.
An implant (e.g., stent) according to exemplary embodiments of the invention described herein can be made from a biocompatible metal material, such as, for example, stainless steel, nickel (Ni) alloys, titanium (Ti) alloys, nickel-titanium alloys, cobalt-based alloys, titanium, tantalum, and other similar suitable metal materials. Examples of nickel, titanium, or nickel-titanium alloys may include NiTi shape memory alloys and NiTi super elastic alloys. Alternatively, the implant can be made from a biocompatible polymer. Examples of biocompatible polymers include polytetrafluoroethylenes (PTFEs), polyetheretherketones (PEEKs), polyesters, polyurethanes, polyamides, ePTFEs, and other similar suitable polymers. Further, the implant may be formed of a bioabsorbable material, for example a bioabsorbable metal or polymer. Examples of suitable bioabsorbable polymers include polylactic acid (PLA), polycaprolactone (PC), and polyglycolic acid (PGA), for example. It is contemplated that any combination of these various materials may also be used to form an implant according to the invention. For example, the hinged portion of the implant could be made of a different material than the remaining portions of the implant. As another example, the various implant sections may be made of differing materials.
Embodiments of the present invention may include various multiple-section hinged implants and are not limited to the embodiments discussed above. For example, the implants need not be in the form of stents, but may be in the form of other types of implants for which it may be desirable to have two or more sections that can pivot relative to each other. Further, the hinged portion or portions joining the various sections of the implant could be configured so that there is a maximum angle at which the various sections may bend relative to each other. As an example, the hinged portion may be configured to self-deploy to assume a desired angle between the joined sections. Additionally, as discussed in more detail below, the implant may be formed of three sections so as to form a “T” shaped configuration, with two of the sections configured to articulate relative to a third section. Further, the entire implant or sections, such as the myocardial and/or vessel section of the implant, may be self-expandable.
The following paragraphs describe exemplary embodiments of delivery systems and methods for inserting a hinged implant into a body part. The following methods are described in connection with delivering and positioning stent 40 into a passage between a left ventricle and a coronary vessel.
Generally, the delivery of an implant may be accomplished by an implant delivery system. An implant delivery system may provide one or more functions, such as providing access to an insertion site or a location near the insertion site, providing a passageway for insertion, delivering an implant into a body, and inserting the implant into the body part, for example. As an exemplary embodiment, one or more catheters may be inserted percutaneously or surgically into a body. The catheter may be inserted into the body with or without a guidewire that guides the entry of the catheter during the insertion process.
In an exemplary embodiment of obtaining access to a heart wall under a percutaneous approach, the catheter may be inserted through a femoral vessel and advanced in the patient's vasculature to a coronary vessel. Alternatively, the catheter may obtain access to the vasculature under an open-chest or other surgical approaches. For example, the catheter may be inserted through the anterior wall and posterior wall of a coronary vessel and then into the heart wall.
The catheter 90 may have several different forms. For example, the catheter 90 may comprise dual side-by-side catheter shafts 105, 106 secured together at least near the proximal end portion of the catheter 90. Such securing of the catheter shafts 105, 106 may assist in reducing twisting of the system. Alternatively, as shown in
Each of the branched shafts 103,104 carries a balloon 107, 108, shown in a deflated state in
Using the delivery system of
Once the guidewires 101,102 are in position, as show in
As shown, the shaft 103′ carrying balloon 107′ is inserted through the opening 48 and the vessel section 44 of the stent 40. The shaft 104′ carrying a balloon 108′ is inserted through the opening 48 and the myocardial section 42, exiting through the end of the myocardial section 42 furthest from the vessel section 44. The loading of the stent 40 onto the catheter 90′ differs from that of
Using the delivery system of
As the catheter 90′ carrying the stent 40 is advanced along the guidewires 101, 102, through the coronary vessel CV, eventually, the shaft 104′ carrying myocardial section 42 will be advanced along guidewire 102 and into the myocardium MYO. As the myocardial section 42 is advanced along guidewire 102 and into the myocardium MYO, the vessel section 44 acts as a “stop” to prevent the vessel section 44 from being advanced into the myocardium MYO and also provides tactile feedback to the physician to ensure proper positioning of the stent 40. In particular, because the vessel section 44 is advanced over the guidewire 101 which extends down the vessel CV, and not into the myocardium MYO, the vessel section 44 is substantially prevented from being advanced into the myocardium MYO. In this way, the stent 40 is deployed with the myocardial section 42 disposed in the myocardium MYO and the vessel section 44 remaining in the vessel CV at a location distal to the location of the myocardial section 42 in the direction of insertion down the vessel CV (i.e., the stent 40 is disposed in the position shown in
In another exemplary embodiment, a self-expandable implant may be used and a sheath delivery mechanism may be used to deliver the implant. Such a sheath delivery mechanism may have a similar structure to the shafts of the catheter-based systems described above with respect to
The vessel section 144 and/or the protection section 150 may be connected to the myocardial section 142 in any suitable combination using any suitable method and/or apparatus set forth herein. For example, two or more of myocardial section 142, vessel section 144, and/or protection section 150 may be integrally connected to each other and/or may be connected to each other via one or more hinges 146 that are substantially similar to the hinge 46 described above. The hinge 146, or any other connector set forth herein, may be made of any suitable biocompatible material, for example, stainless steel. Alternatively, the vessel section 144 and/or protection section 150 may be connected to the myocardial section 142 via other connection mechanisms, such as, for example, tethers or a weld.
For example, myocardial section 142 and vessel section 144 may be integrally connected to each other via hinge 146 (e.g., hinge 146 may be machined from the same piece of material as myocardial section 142 and vessel section 144), and then protection section 150 may be a separate section connected to one of myocardial section 142 and vessel section 144 via a tether or weld. In another example, myocardial section 142, vessel section 144, and protection section 150 may each be separate sections connected by welds and/or discrete tethers. In a further example, myocardial section 142 may be connected to vessel section 144 via a first weld or tether, and protection section 150 may be connected to myocardial section 142 via a second weld or tether. In another example, two or more of myocardial section 142, vessel section 144, and protection section 150 may be connected to each other via both hinge 146 and a tether.
When deployed, the stent 140 may have a substantially T-shaped configuration. A tether, or any other connector set forth herein, may be made of any suitable biocompatible material, for example, PTFE. For example, as shown in
The stent 140, including the vessel section 144, myocardial section 142, and protection section 150, may be fabricated in a variety of ways. For example, the vessel section 144, myocardial section 142, and protection section 150 may be fabricated from the same section of tubing. Alternatively, the vessel and protection sections 144, 150 may be fabricated from the same tubing and then connected to the myocardial section 142 via, for example, welding, tethers, or other connection mechanisms. In another example, the vessel section 144 and myocardial section 142 may be connected to each other (e.g., formed from the same tubing), and then the protection section 150 may be connected to the myocardial section 142. In another exemplary embodiment, the protection section 150 could be separated (e.g., not connected) to the hinged stent made of the myocardial and vessel sections 142, 144. In this configuration, the protection section 150 could be delivered to the vessel before or after the hinged stent has been implanted. The protection section 150 may then be connected to one of the myocardial and vessel sections 142, 144.
Guidewires 201, 202 may be deployed in the coronary vessel and/or the myocardium using any method known in the art, for example, percutaneously.
A first portion 321 of a guide tool 320 may then be advanced over first guidewire 201. As shown in
End 321a of first portion 321 may be placed through puncture site PS and into coronary vessel V. First portion 321 may be advanced into coronary vessel V until a surface 322a of second portion 322 is substantially flush with an outer surface OS of the coronary vessel V, for example, as shown in
A sharp end 220b of a puncture tool 220 may then be advanced through guides 321b, 322b (e.g., holes) disposed on first and second portions 210, 220 on guide tool 320, and into the myocardium, for example, as shown in
Once second guidewire 202 has been deployed, puncture tool 220 may be removed from guides 321b, 322b and second guidewire 202 may remain in the coronary vessel V and the myocardium because second guidewire 202 may exit the lumen of puncture tool 220 via slit 222. Accordingly, guidewires 201, 202 may be disposed in coronary vessel V and myocardium MYO, for example, as shown in
Once guidewires 201, 202 have been placed in the coronary vessel and/or heart wall, stent 140, 240 may be deployed, for example, as shown in
In one embodiment shown in
Once stent 140 is disposed on first and second catheters 203, 204, stent 140 may be advanced along first and second guidewires 201, 202. The stent 140 may then be advanced into the coronary vessel V along the guidewires 201, 202 with the myocardial section 142 and the protection section 150. Once the stent 140 reaches the appropriate site in the coronary vessel and/or myocardium, the myocardial portion 142 may be advanced through the myocardium via the second guidewire 202 (e.g., pivoted toward the vessel section 144 and/or away from protection section 150) and the protection section 150 may be advanced further down the coronary vessel via the first guidewire 201. Thus, stent 140 may assume the configuration shown in
In another embodiment shown in
Once stent 240 is disposed on first and second catheters 203, 204, stent 240 may be advanced along first and second guidewires 201, 202. The stent 240 may then be advanced into the coronary vessel V along the guidewires 201, 202 with the myocardial section 242 and the protection section 250. Once the stent 240 reaches the appropriate site in the coronary vessel and/or myocardium, the myocardial portion 242 may be advanced through the myocardium via the second guidewire 202 (e.g., pivoted toward the vessel section 244 and/or away from protection section 250) and the protection section 250 may be advanced further down the coronary vessel via the first guidewire 201. Thus, stent 240 may assume the configuration shown in
The various delivery techniques and tools described with reference to
Embodiments of a stent according to the present invention may have a variety of alternate configurations. For example, a protection section 250 may be a stent-like slotted tubing structure as shown in
The stent 240, including the vessel section 244, myocardial section 242, and protection section 250, may be fabricated in a variety of ways. For example, the vessel section 244 and protection section 250 may be fabricated separately and then connected. The myocardial section 242 may be connected to the vessel section 244 prior or subsequent to connection of the vessel section 244 and the protection section 250. In another example, the vessel section 244 and protection section 250 may be fabricated from the same section of tubing with portions of the tubing being removed. The myocardial section 242 may then be connected to the vessel section 244.
In another example, a protection section 350 may be a metal ring connected to a myocardial portion 342, as shown in
In a further example, the protection section may be an extension of the vessel section with an opening for the myocardial section to be placed therethrough.
The hinged stent body 1000 shown in
Hinged stent body 1000 may have any suitable dimensions. For example, hinged stent body 1000 may have a full length, as defined in
The hinged stent body 1000 shown in
In another example, a high distal edge E may be formed on first section 1101 by cutting implant 1100 along line 1105 at an angle so as to form second section 1102 and first section 1101 connected by connector 1103, for example, as shown in
As shown in
As shown in
For example, the stent sections 170, 180 may have extended grip regions 171, 181, with holes 172, 182, respectively connected to struts of the stent sections 170, 180 via extensions 173, 183. The ends of the extended grip regions 171, 181 also may be connected to each other via a notched connection region 190. The extended grip regions 171, 181 may be connected by fabricating the stent sections 170, 180 from the same piece of metal and machining the notched region 190 in such a configuration. Alternatively, the stent sections 170, 180 may be fabricated separately and the stent sections 170, 180 may subsequently be joined together so as to form the notched region 190. Another connector 200 may be disposed through the holes 172, 182.
The notched region 190 may be used as a weak hinge connector. The notched region 190 may allow stent sections 170, 180 to articulate relative to each other without necessarily breaking. The notched region 190 may assist in the deployment of the stent sections 170, 180 in a connected (e.g., substantially straight) configuration, for example, as the stent sections 170, 180 make their way into the body through a coronary vessel, by allowing alignment of the stent sections 170, 180 relative to each other. Once the stent sections 170, 180 have been positioned in the appropriate portion of the coronary vessel and/or myocardium, the notched region 190 may allow the stent sections 170, 180 to articulate with respect to each other. Over time, continued bending of notched region 190, for example, as stent sections 170, 180 articulate relative to each other, may cause notched region 190 to fatigue and break. Even if this were to occur, however, stent sections 170, 180 may still be connected via connector 200.
There are several advantages to using connectors set forth in
In another example, at least some of the connectors set forth in
In addition to the various delivery steps discussed above, any type of delivery approach used could include a step of measuring the heart wall thickness and determining the appropriate stent size based on the measured thickness. Such measuring could be done by numerous means apparent to those skilled in the art, including using various imaging techniques, wave generator (e.g., pressure monitoring) techniques, insertion of a device, such as a needle, for example, with graduated markings and a mechanism for observing blood flow through the device to determine it has reached the chamber and/or vessel, and other suitable measuring techniques.
Moreover, as discussed above, a vessel blocking device may be implanted in the vessel in conjunction with a hinged implant. In such cases, it may be desired to measure various vessel flow parameters, such as pressure, for example, and choose a blocking device based on the measured flow parameters. For examples of blocking devices and implanting such devices into coronary vessels, reference is made to U.S. Patent Application Publication No. 2005-0070993 A1, incorporated herein.
Alternatively, the stent may be delivered to the heart wall and coronary vessel from the heart chamber. It should also be appreciated that the myocardial section of the stent need not be positioned perpendicular to the longitudinal axis of the coronary vessel, but could be positioned at a different angle.
Further, prior to delivering the myocardial section into the heart wall MYO, an optional step may be used to provide a passageway within the heart wall MYO. The passageway, if formed, may facilitate the insertion of the myocardial section. A variety of techniques may be employed to form such a passageway including, but not limited to, using ablation techniques, dilation techniques, including balloon dilation or the insertion of a series of dilation catheters, for example, and other tissue removal techniques.
The various hinged implants described herein may be made using a variety of techniques. For example, in an exemplary aspect, when the hinged implants are in the form of stents, conventional techniques, such as, for example, laser etching and/or chemical etching of solid tubes may be used to form the stent, and/or welded wire structures may be used.
As noted above, various methods and delivery tools may be used to deliver and insert an implant into different body parts. Skilled artisans may use any embodiments, modifications and variations thereof, and other conventional techniques to deliver and insert any implant of the invention. In other words, skilled artisans may use delivery or insertion techniques known in the art to deliver or insert the devices according to embodiments of the invention.
It will be apparent to those skilled in the art that various modifications and variations can be made in the exemplary devices and methods described above and in the construction of those devices and methods. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only.
