The present invention relates generally to catheters for introduction into body lumens within a patient's body, and, more particularly, to complexly shaped catheters for accessing body lumens, cavities, and/or visualization within a patient's body and to methods for constructing and using such catheters.
Minimally invasive procedures have been implemented in a variety of medical settings, e.g., for vascular interventions, such as angioplasty, stenting, embolic protection, electrical heart stimulation, heart mapping and visualization, tissue ablation, and the like. One such procedure involves delivering an electrical lead into a coronary vein of a patient's heart that may be used to electrically stimulate the heart. Another procedure involves delivering an electrode probe into a patient's heart to ablate tissue, e.g., surrounding the pulmonary ostia to treat atrial fibrillation.
In accordance with one embodiment, an apparatus is provided for treating a condition within the patient's heart. A patient's heart anatomy has been shown to vary, especially when the patient suffers from various heart related afflictions, e.g., chronic heart failure. The geometry of the venous system leading to and including the right atrium may vary widely between patients, as may the origin and/or trajectory of the coronary sinus. Taken together, these variations make transvenous coronary sinus access challenging, e.g., to deliver a catheter, lead, or other device into the coronary sinus. Patients undergoing such procedures may suffer hardship given available devices, e.g., because of the delay or other difficulty in accessing the coronary sinus. In some situations, because such access may be monitored tactilely or using two-dimensional imaging, such as fluoroscopy, a physician may be unable to access the coronary sinus in some anatomy. Thus, patients and physicians would benefit from an apparatus that can accommodate complex anatomical variations.
Accordingly, apparatus and methods for delivering devices into a patient's vasculature, e.g., the coronary sinus, or other body lumens would be useful.
The present invention is directed generally to apparatus and methods for accessing body lumens within a patient's body and/or visualization within a patient's body and to methods for making and using such apparatus. More particularly, the present invention is directed to complexly shaped catheters for accessing body lumens and/or cavities, apparatus including such catheters, and methods for making and using them.
In accordance with one embodiment, an apparatus is provided that includes a flexible tubular member including a proximal end and distal end sized for introduction into a body lumen, and a steerable distal portion. The distal portion maybe controlled using one or more actuators, e.g., on a handle on the proximal end. In one embodiment, the proximal end of the tubular member may be substantially rigid or otherwise may remain substantially straight relative to the distal end. The distal portion may be deflectable through a simple arc, e.g., using a pull-wire or other mechanism. In addition or alternatively, the distal portion may be shaped, i.e., the material of the distal portion may have a shape set into the material, thereby biasing the distal portion to assume a predetermined shape, twist, and/or other deflection when free from external forces.
In one embodiment, the distal portion may be biased towards a curvilinear shape and/or may include a torsion or twist. A desired combination of predetermined shape and/or deflection characteristics, as well as a steering mechanism, may be selected to facilitate positioning the distal end of the tubular member relative to an anatomical feature within a body cavity.
In an exemplary embodiment, the predetermined shape of the distal portion may include a bend within a first plane, e.g., biased to an angle of approximately thirty degrees (30°) relative to a substantially straight portion of the tubular member proximal to the bend. In addition, the distal portion may be steerable, e.g., such that the distal end may be directed out of the first plane. The distal portion may be steerable within a second plane intersecting the first plane, e.g., at an angle up to approximately ninety degrees (90°). Alternatively, the bend and/or the deflection of the distal portion may be more complex than defining a single plane.
In one embodiment, the bend may be defined by the left hand rule for helixes. For example, the direction of rotation of the distal portion may be represented by fingers of the left hand curving outward from the hand with the thumb defining, when extended from the hand, the general direction of propagation. Such a configuration may be particularly useful for cannulating the coronary sinus from a superior approach, i.e., when the right atrium is accessed from the superior vena cava. Specifically, a left handed helical deflection creates a direction vector at the tip of the device that matches the generally anatomically posterior entry vector of the coronary sinus ostium. Matching the tip vector with the entry vector facilitates much improved cannulation as compared to a simple tip curvature that may succeed in placing the tip of the device at the coronary sinus ostium but does not approach the sinus at a sufficiently ideal entry direction to facilitate cannulation. A left handed helical deflection is especially necessary when the location of the ostium relative to the entry plane of the device through superior vena cava exacerbates the mismatch of the entry vector of the sinus with the approach direction of a simple deflectable or shape set catheter.
In accordance with another embodiment, any of the apparatus described herein may include a transparent expandable member, e.g., a balloon or other membrane, on the distal end, and/or an imaging assembly including a distal lens, e.g., disposed proximal to or otherwise within the transparent expandable member. A bend, twist, or other deflection may be programmed into the distal portion proximal to the expandable member and/or the imaging system. The section of the tubular member extending beyond the bend may be generally straight and/or substantially rigid, e.g., which may maintain a view angle of an imaging lens of the imaging system substantially aligned with a distal face of the expandable member.
In addition or alternatively, the distal portion of the apparatus may be steerable or otherwise deflected, which may be limited to the distal portion proximal to the bend and/or proximal to the expandable member and/or imaging system.
In accordance with yet another embodiment, an apparatus is provided that includes a flexible distal portion including multiple predetermined bends set therein and may be steerable in one or more planes. A distal end of the apparatus, e.g., beyond the bends and/or steerable portions, may include a transparent expandable member, imaging assembly, and/or other components. For example, the distal portion may include a first bend having an angle of approximately thirty degrees (30°) relative to a substantially straight portion of the tubular member proximal to the first bend, and may steerable such that the distal portion may be directed up to approximately ninety (90°) degrees out of the plane formed by the straight proximal tubular member and the distal tubular member when deflected. In addition, the distal portion may include a second bend defining a twist, e.g., that is counter clock-wise to form a corkscrew or helical area in the distal portion of the tubular member. In addition, the distal portion may include a third portion, e.g., defining a posterior curve within another plane.
The corkscrew or other twisted portion of the distal portion may vary in length and/or location on the distal portion, depending on intended anatomical structures of a body cavity into which the apparatus is to be delivered. For example, if the apparatus approaches the right atrium of a heart from a superior position, the distal portion may be configured to move in a slight rightward inferior motion as it approaches the coronary sinus and then curve left in a posterior motion of deflection. This configuration may allow the tubular member to be manipulated through anatomical structures of a body cavity, e.g., through the right atrium into the coronary sinus.
The apparatus may be formed from one or more materials that may have one or more bends programmed therein, may be deflected or otherwise steered, while remaining flexible and structurally intact.
More particularly, the first bend may be defined by the left hand rule. The direction of rotation of the distal portion may be defined by fingers of the left hand curving outward from the hand with the thumb defining the general direction of propagation when extended from the hand. The catheter may also be deflectable further as described elsewhere herein, the combination of deflection and multiple bends providing a range of complex shapes of the distal portion.
In a further embodiment, the deflectable distal portion may be deflected to form an approximately helical configuration. For example, when cannulating the coronary sinus from a superior approach, this helical configuration may follow the left hand rule where the thumb points distally along a longitudinal axis of the apparatus, and the curled fingers representing the bend may wrap in the direction of the helical curve adopted by the distal portion of the apparatus. Alternatively, it may be desirable to configure the distal portion according to a right hand rule, e.g., if accessing the coronary sinus from an inferior approach, i.e., via the inferior vena cava.
In yet an alternative embodiment of the twisted and/or helical shape, the apparatus may be constructed such that the distal portion includes a twist, e.g., linear in pitch, such that deflection of a distal portion of the apparatus in at least one plane is substantially linear throughout most of the deflection of the distal portion. Alternatively, the steerable distal portion of the apparatus may deflect orthogonally to the direction of deflection in at least one plane such that the tip position defines a substantially linear pathway throughout most of the deflection. This configuration may allow the distal tip to be maintained within an open space of an atrium as it transitions from a straight undeflected configuration towards a desired complex curved configuration, e.g., for cannulating the coronary sinus or other body lumen, as described elsewhere herein.
In addition, this configuration may allow the apparatus to reach a desired shape without substantial interference with the boundaries of the atrium or body cavity. Second, the substantially linear tip deflection in at least one plane, may promote ease of understanding the position of the tip given the complex curve of the apparatus, e.g., while monitoring the apparatus using a two-dimensional imaging or reference system, such as fluoroscopy or other x-ray system.
In a further embodiment, the apparatus may be deflectable to substantially form two arcs defining approximately perpendicular planes. Optionally, if desired, the arcs may follow the left hand rule, the first arc curving in the direction of the curved thumb, and the second arc curving in the direction of the curved fingers of the left hand.
In yet another alternative, any of the apparatus described herein may also include a slidable inner member disposed adjacent to a pull wire and/or otherwise adapted to modulate a location at which the pull wire may cause the distal portion to begin deflection, for example, as described elsewhere herein. In combination with the helical and/or double arc configurations, the pullwire or an inner member may be used to induce approximately lateral motion of the distal tip of the apparatus, e.g., approximately perpendicular to the motion caused by deflection. The radius of curvature, spiral diameter, and/or other dimensions of the distal portion may be adjusted using the slidable inner adjustment member.
In a further embodiment, the helical or double arc configuration may be combined with one or more bends along the length of the catheter to generate further complex geometry.
Any embodiment of the apparatus described herein may also include a transparent expandable member, e.g., at its distal tip, and/or an imaging system having a distal lens disposed proximally within the expandable member.
In accordance with another embodiment, an apparatus is provided for treating a condition within a patient's heart that includes a flexible tubular member including a proximal end, a distal end sized for introduction in to a body lumen, and a substantially transparent expandable member carried by the distal end of the tubular member. The proximal end of the tubular member may remain substantially straight and/or rigid relative to the distal end. The proximal end may merge with a complex curved distal end, which may be shaped to seat the tubular member relative to an anatomical feature within a body cavity.
The complexly shaped distal end may have a first portion that may be curved out of plane relative to the proximal end. The out of plane curve may be anterior and left, demonstrating a curvature with a gradual deflection of up to forty degrees (40°) from the plane of the proximal end. The gradual curvature deflection may have an appearance of an S-shape, an L-shape, a J-shape, and/or some combination in which the shape provides an alternative angle that is out of alignment with the direct plane of the proximal end. The tubular member may be formed from any substantially flexible and/or semi-rigid material, which may be deflectable while remaining flexible and structurally intact.
In accordance with still another embodiment, apparatus and/or method are provided for cannulating a coronary sinus within a patient's heart from a superior approach. The apparatus may include a flexible tubular member including a proximal end, and a distal end sized for introduction into a body lumen. The distal end may be steerable and also preformed such that, through the combination of steering and the pre-shape, a range of complex shapes may be selectively achievable upon actuation from the proximal end. The distal end of the tubular member body may be steerable when attached to a steerable catheter handle. Exemplary steerable catheter handles may be found in co-pending application Ser. No. 11/062,074, filed Feb. 17, 2005, the entire disclosure of which is expressly incorporated herein by reference.
Optionally, the distal end may include a substantially transparent expandable member carried by the distal end of the tubular member, and an optical imaging assembly carried by the distal end of the tubular member and at least partially surrounded by the expandable member for imaging tissue structures beyond the distal end through the expandable member. A preformed distal end of the expandable member may facilitate the optical imaging assembly keeping the image in alignment with the distal end of the tubular member. The optical imaging assembly and apparatus and methods for making and using them may be found in co-pending application Ser. No. 11/062,074, filed Feb. 17, 2005, the disclosure of which is expressly incorporated by reference herein.
In accordance with still another embodiment, a method is provided for making a complex curved distal portion for a catheter or other apparatus. An elongate tubular body may be provided sized for introduction into a patient's body, and a shape may be set into the body such that the body remains flexible but may be biased to the shape. A pullwire or other steering mechanism may be directed through the body and fixed adjacent one end. The body may include an extrusion or other core, and an outer layer surrounding the core.
In one embodiment, the body may be twisted about its central axis, and the twist set into the body, while in another embodiment, the body may be set into a simple curved shape, a helical shape, and the like. The body may include a passage extending along the body but offset radially from a longitudinal axis of the body, and the steering mechanism may be inserted through the passage and fixed at one end of the body. When the steering mechanism is subjected to axial force, e.g., pulling or pushing the steering mechanism from an end opposite the fixed end, the steering mechanism may cause the body to assume a complex curved configuration, such as those described elsewhere herein.
In addition to including the catheters described herein as an apparatus for accessing body lumens, cavities, and/or recesses, the catheters may also be used for other medical procedures within a patient's body. For example, the catheters may be included in a delivery system, wherein the complex curved distal end may be modified to carry a needle with stem cells, medicaments, and the like. Alternatively, the apparatus may carry an energy probe or other instrument disposed on or deployable through the tubular member. For example, the probe may be used for delivering electrical, laser, thermal, or other energy to tissue in the region beyond the tissue structure. In yet a further alternative, the apparatus may include one or more electrodes for recording electrical signals.
Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.
The drawings illustrate exemplary embodiments of the invention, in which:
Turning to the drawings,
Generally, as shown in
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The catheter 12 may be substantially flexible, semi-rigid, and/or rigid along its length, and may be formed from a variety of materials, including plastic, metal, and/or composite materials. For example, the catheter 12 may be substantially flexible at the distal end 16, e.g., to facilitate steering and/or advancement through tortuous anatomy, and/or may be semi-rigid or substantially rigid at the proximal end 14, e.g., to enhance pushability of the catheter 12 without substantial risk of buckling or kinking. In addition, as described further below, the distal end 16 may include a bend, twist, deflection, or other shape programmed or set into the distal end 16. Thus, the distal end 16 may assume the predetermined shape in a relaxed condition, e.g., free from external forces, but may be substantially flexible so that the distal end 16 may be directed from the relaxed condition, e.g., using a steering mechanism and/or when directed through tortuous anatomy.
In an exemplary embodiment, the catheter 12 may be formed from PEBAX, which may include a braid or other reinforcement structure therein. For example, as shown in
Optionally, the plastic core 12a may include a composite construction. For example, a portion of the catheter 12 adjacent the distal end 16 may include semi-cylindrical portions of different materials that may be secured together to provide a tubular body. For example, the last several inches, e.g., up to eight inches, adjacent to the distal end 16 may include upper and lower halves or portions (not shown) that may be bonded or otherwise secured together or formed in a divided extrusion process. In an exemplary embodiment, the upper half, e.g., including imaging fibers 62, 64, may be made from polyurethane, and the lower half, including the accessory lumen 20a and/or inflation lumens 20b, may be made from PEBAX. Alternatively, the upper half may be made from a lower durometer PEBAX and the lower half from a higher durometer PEBAX. Alternatively, other materials may be selected having differential physical properties to facilitate directionality or biasing of deflection of the catheter 12, as described elsewhere herein. For example, such composite construction may provide a desired off-axis center of modulus or hinge, as explained further below.
Optionally, as shown in
The first section 40a may be at least partially inserted into the distal end 16 of the catheter 12, e.g., into the accessory lumen 20a. For example, the material of the distal end 16 may be softened to allow the material to reflow as the first section 40a of the tubular extension is inserted into the accessory lumen 20a. Alternatively, the distal end 16 may include a recess (not shown) sized for receiving a portion of the first section 40a therein. In addition or alternatively, the first section 40a may be attached to the distal end 16 by bonding with adhesive, using mating connectors and/or an interference fit, and the like. The second section 40b may be bonded or otherwise attached to the first section 40a before or after the first section 40a is attached to the distal end 16 of the catheter 12.
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A device, e.g., a display 82, computer or other device (not shown) may be coupled or otherwise provided at the proximal end 14 of the apparatus 10 for acquiring, capturing, and/or displaying images transmitted by the imaging fiber 64. For example, as shown in
The device coupled to the fiber bundle 64 may include a CCD, CMOS, and/or other device, e.g., to digitize or otherwise convert the light images from the imaging fiber 64 into electrical signals that may be transferred to a processor and/or display. The device may be coupled to the monitor 82, e.g., by a cable 84, as shown in
The imaging assembly 60 may also include one or more illumination fibers or light guides 62 carried by the distal end 16 of the catheter 12 for delivering light into the interior 52 and/or through a distal surface 54 of the balloon 50. As shown in
As shown in
Optionally, if the distal end 16 has a nonlinear shape in the first, related configuration, the catheter 12 may include a stiffening member (not shown), which may be advanced into the distal end 16 to at least partially straighten the distal end 16. For example, the stiffening member may be biased to a substantially straight (or other) shape and may have a rigidity greater than the distal end 16, while still being substantially flexible to accommodate bending. Thus, when the stiffening member is advanced into the distal end 16, the distal end 16 may become biased to assume the substantially straight (or other) shape of the stiffening member. When the stiffening member is withdrawn from the distal end 16 (e.g., using an actuator, not shown, in the handle 30), the distal end 16 may become biased to assume its nonlinear relaxed configuration.
In addition, the catheter 12 may be steerable, e.g., the distal end 16 may be controllably deflectable transversely relative to the longitudinal axis 18 using one or more pullwires or other steering elements. In the embodiment shown in
With continued reference to
For example, when the optical fiber 64 is pulled proximally or pushed distally relative to the catheter 12, e.g., from the proximal end 14 of the catheter 12, a bending force may be applied to the distal end 16, causing the distal end 16 to curve or bend transversely relative to the central axis 18. Optionally, the degree of steerability of the distal end 16 may be adjustable, e.g., to increase or decrease a radius of curvature of the distal end 16 when the imaging fiber 64 is subjected to a predetermined proximal or distal force. In addition or alternatively, one or more regions of the catheter 12 may be set to be steerable in a predetermined manner.
For example, any of the catheters 12 described herein may include a steering adjustment member, which may be an elongate member 80 slidably disposed within the catheter 12. For example, as shown in
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With continued reference to
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Referring to
Optionally, any of the embodiments described herein may include a substantially transparent expandable member on a distal end of the catheter or other apparatus, an optical imaging assembly on the distal end, and/or other features or structures, depending upon the intended use for the apparatus, e.g., as described above. The preformed distal end may allow an optical imaging assembly to keep its field of view, and any image therein, in alignment with the distal end of the apparatus.
Turning to
Generally, the catheter 12 may be advanced from an entry site, e.g., a percutaneous puncture in a peripheral vein or other vessel, into the superior vena cava 180. From the superior vena cava 180, the catheter 12 may enter the right atrium 185, which may diverge anatomically relative to the coronary sinus 186. For each patient, the connecting region of the right atrium 185 between the superior vena cava 180 and the coronary sinus 186 may define a pathway, which may be modeled in order to define connect the superior vena cava pathway 180 with the coronary sinus trajectory pathway 183, as measured from the individual patient being treated.
Referring to
Thus, as can be seen, the necessary pathway to navigate successfully from the superior vena cava to the coronary sinus may vary dramatically, which can make navigation through a particular patient's heart difficult to predict, and, in practice, difficult to accomplish. The complex curved configurations achievable with the apparatus described herein may facilitate such navigation, but providing a shape configured to place the tip of the apparatus within close proximity to the coronary sinus. By then steering or otherwise manipulating the apparatus, the coronary sinus may be located and/or accessed more easily.
Turning to
If, in some particular anatomy, the coronary sinus 186 is located towards the right side of the patient (towards the superior vena cava 180) or more posteriorly, the axes 181, 187 may become closer to intersecting, and a simple curved catheter may have a better chance of approximating the coronary sinus 186. If the coronary sinus 186 is located to the patient's left or more anteriorly, the axes 181, 187 may diverge even further, making approximating the coronary sinus 186 more difficult. Similar difficulties may emerge if the coronary sinus is oriented more clockwise or if the axis 187 of the coronary sinus 186 does not lie within the plane of the cross-section of
While the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the scope and spirit of the description and limited only by the claims.
This application claims benefit of provisional application Ser. Nos. 60/678,517, filed May 6, 2005 and Ser. No. 60/752,763, filed Dec. 20, 2005. The entire disclosures of these applications are expressly incorporated herein by reference.
Number | Date | Country | |
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60678517 | May 2005 | US | |
60752763 | Dec 2005 | US |