The present teachings generally relate to an energy assisted tissue piercing device, for example, for piecing heart valve tissue. The present teachings also relate to using a delivery system with such an energy assisted tissue penetration device to create an aperture percutaneously.
Transeptal puncture is a commonly performed procedure that allows access to the left atrium. The most common uses for transeptal catheterization include direct measurement of the left atrial pressure or providing access to the left ventricle in patients with prosthetic aortic or mitral valves or in patients who are undergoing percutaneous mitral valvuloplasty etc.
Historically, conventional rigid, long needles, such as Brockenbrough or Ross needles, are used for this procedure to mechanically puncture the atrial septum. And a challenge for a successful transept puncture with a Brockenbrough needle is to position the Brockenbrough needle at the thinnest aspect of the atrial septum, the membranous fossa ovalis. Although the procedure is generally safe, serious complications, such as inadvertent puncture through tissues other than the septum, for example, the atrial free wall, pose a significant risk to the patient.
Many companies are working to improve the drawback associated with the Brockenbrough needle. St. Jude Medical Inc.'s ACross™ Transeptal Access System, which consolidates a sheath, a dilator and a needle into a single interlocking handle, gives a clinician a greater control over precisely positioning the device and ensures that the puncture needle is only advanced for a predetermined distance. Baylis Medical's NRG™ RF Transeptal Needle uses radiofrequency energy emitted from the needle tip to assist the needle in transeptal access. NRG™ RF needle is insulated with a closed end that safely delivers radiofrequency energy to create a small hole in the atrial septum, allowing the needle to pass to the left atrium with increased efficacy and control. Pressure Product's SafeSept™ septal puncture system includes a delivery catheter and a sharp tipped wire. When supported by the delivery catheter, the sharp tip of the wire ensures an effortless penetration of the septal tissue. When unsupported by the delivery catheter, the tip of the wire assumes a ‘J’ shape, rendering it incapable of penetrating tissues.
The left atrium is the most difficult chamber to access percutaneously. In addition, most septal puncture location is applied at the fossa ovalis, the thinnest part of the atrial septum. Thus there exists a need for a clinician to safely penetrate heart tissue percutaneously at any treatment location, whether it is the thickest or the thinnest, or intact or scarred tissue. In addition, an ideal transeptal puncture system should be able to precisely control the puncture location, avoid needle slippage and inadvertent puncturing, and is easy for a clinician to practice.
One aspect of the present teachings provides a device for piercing heart tissue percutaneously. The device comprises a first outer catheter, a second inner tissue piercing wire, and an energy source connecting to the second inner tissue piercing wire. The first outer catheter has a proximal end, a distal end and a lumen longitudinally disposed therethrough. The second inner tissue piercing wire has a conductive inner wire and an insulation outer layer. The second inner tissue piercing wire slidably disposes within the lumen of the outer catheter. The conductive inner wire of the second inner tissue piercing wire has a proximal portion, a distal portion, and an intermediate portion. The intermediate portion is narrower than the proximal portion and distal portion of the conductive inner wire.
Another aspect of the present teachings also provides a device for piercing heart tissue percutaneously. The device comprises a first outer catheter, a second inner tissue piercing wire, and an energy source connecting to the second inner tissue piercing wire. The first outer catheter has a proximal end, a distal end and a lumen longitudinally disposed therethrough. The second inner tissue piercing wire has a proximal portion, a distal portion and an intermediate portion between the proximal and distal portions. The second inner tissue piercing wire is configured to transition from a delivery profile to a deployed profile. In the delivery profile, the distal portion of the second inner tissue piercing wire is disposed within the lumen of the first outer catheter, and substantially aligns with the proximal portion of the second inner tissue piercing wire. In the deployed profile, the distal portion is exposed outside of the lumen of the first outer catheter, and pivots from the proximal portion of second inner tissue piercing wire.
a is a perspective view of an exemplary tissue piercing wire in accordance with the present teachings;
b is a perspective view of an exemplary tissue piercing wire in accordance with the present teachings;
a is a perspective view of an exemplary energy assisted tissue piecing device deploying across a tissue in accordance with the present teachings; and
b is a perspective view of an exemplary energy assisted tissue piecing device deploying across a tissue in accordance with the present teachings.
Certain specific details are set forth in the following description and Figures to provide an understanding of various embodiments of the present teachings. Those of ordinary skill in the relevant art will understand that they can practice other embodiments of the present teachings without one or more of the details described below. Thus, it is not the intention of the Applicants to restrict or in any way limit the scope of the appended claims to such details. While various processes are described with reference to steps and sequences in the following disclosure, the steps and sequences of steps should not be taken as required to practice all embodiments of the present teachings.
As used herein, the term “lumen” means a canal, a duct, or a generally tubular space or cavity in the body of a subject, including a vein, an artery, a blood vessel, a capillary, an intestine, and the like.
As used herein, the term “proximal” shall mean closest to the operator (less into the body) and “distal” shall mean furthest from the operator (further into the body). In positioning a medical device inside a patient, “distal” refers to the direction away from a catheter insertion location and “proximal” refers to the direction nearer the insertion location.
As used herein, the term “wire” can be a strand, a cord, a fiber, a yarn, a filament, a cable, a thread, or the like, and these terms may be used interchangeably.
The following description refers to
Unless otherwise specified, all numbers expressing quantities, measurements, and other properties or parameters used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, it should be understood that the numerical parameters set forth in the following specification and attached claims are approximations. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, numerical parameters should be read in light of the number of reported significant digits and the application of ordinary rounding techniques.
The present teachings described herein relates to devices and methods for puncturing the mitral annulus via a percutaneous route. The devices and/or methods can be used to repair the mitral valve, for example, to treat the mitral regurgitation or other related mitral valve diseases. It, however, should be appreciated that the present teachings are also applicable for other parts of the anatomy or for other indications. For instance, a device such as one described in the present teachings can be used to puncture the atrial septum, the tricuspid annulus and etc.
One aspect of the present teachings relates to an energy assisted tissue piercing device and methods of using such a device to percutaneously penetrate the mitral armulus. In some embodiments, the device creates a controlled perforation with the distal tip through the application of radio frequency (RF) energy. In some embodiments, the device has a generally straight profile before perforation. In some embodiments, the device has a curved profile upon entering the other side of the annulus tissue. The curved profile can direct the distal tip of the device away from the cardiac structures, thereby decreasing the likelihood of injury, including inadvertent cardiac perforation.
According to some embodiments of the present teachings, the energy assisted tissue piecing device includes a delivery catheter, a tissue piercing wire, and an energy source connected to the tissue piercing wire. The delivery catheter has a proximal portion, a distal portion, and an elongated lumen extending from the proximal portion to the distal portion. The tissue piercing wire also has a proximal end, a distal end, and an elongated body in between. The tissue piercing wire includes an insulated body and an un-insulated distal tip. In some embodiments, the tissue piercing wire has a deflectable distal portion. In some embodiments, the ability of the piercing device to deflect is achieved by using a flexible material or a shape memory material connecting the distal portion to the rest of the wire. Alternatively, the ability to deflect is achieved with geometrical modifications of the wire.
The tissue piercing wire (14) of some embodiments is axially disposed within the lumen (26) of the delivery catheter (12) as illustrated in
a illustrates a detailed construction of an exemplary tissue piercing wire (14) according to one embodiment of the present teachings. The tissue piercing wire (14) includes a conductive inner wire (40), and an insulation outer layer (50).
According to another embodiment of the present teachings as illustrated in
Still referring to
In some embodiments of the present teachings, the conductive inner wire is made of a material conventionally used for guide wires. Examples of the material include a straight stainless steel wire, a coiled stainless steel wire, a glass fiber, a plastics material, nitinol, and etc. In other embodiments, the insulation layer is made of a non-conductive polymer, such as a polyimide, PEBAX®, a polyethylene, a polytetrafluoroethylene (PTFE), a poly(fluorinatedethylenepropylene) (FEP), and a polyurethane, and etc.
According to some embodiments, the proximal end of the tissue piercing wire (14) is connected to an energy source (11). The energy source (11) can provide one or more energy types, including, but not limited to, microwave, infrared, visible light, ultraviolet rays, x-rays, gamma rays, cosmic rays, acoustic energy, thermal energy, or radio frequency energy. In certain embodiments, the energy source (11) is radio frequency energy (RF). For example, the energy source (11) is connected directly to the tissue piercing wire (14) as illustrated in
According to some embodiments, the delivery catheter (12) provides structural support for the tissue piercing wire (14). In some embodiments, the delivery catheter (12) also functions as a dilator. In some embodiments, the inner diameter of the lumen of the delivery catheter (12) typically approximates the outer diameter of the tissue piercing wire (14) such that the delivery catheter (12) provide support to the wire during crossing.
In some embodiments, the device may further comprise a delivery sheath through which the device passes from outside the patient's body through a vessel. In some embodiments, the device comprises a control handle at the proximal end of the sheath. The sheath and/or other components of the delivery system may be steerable by using actuators (not shown) on the control handle to aid in delivering and deploying the device along the tortuous vascular path leading to the treatment site.
According to some embodiments, the narrower intermediate portion (62) of the inner wire (40) allows the inner wire (40) to have a greater flexibility or bendability than the remaining portions of the wire. This narrower intermediate portion (62) can allow the distal portion (64) of the wire to bend when the distal portion (64) of the inner wire (40) extends outside the delivery catheter (12) (as described when referring to
According to some embodiments, the length of the distal portion (64) is from about 5 mm to about 30 mm. In some embodiments, the length of the intermediate portion (62) is from about 5-15 mm. Preferably, the distal portion (64) is 11-13 mm long and the intermediate portion (62) is 12-14 mm long. In other embodiments, the transitioning portions (66, 68) between the intermediate and the proximal (60) or distal (64) portion is 3-63 mm long.
According to some embodiments of the present teachings, the distal and proximal portions (60, 64) of the inner wire (40) have the same diameter as illustrated in
Alternatively, the distal and proximal portions (60, 64) of the inner wire (40) have different diameters. In some embodiments, the distal portion (64) is narrower than the proximal portion (60). In other embodiments, the proximal portion (60) is narrower than the distal portion (64). In certain embodiments, one of the proximal and distal portions (60, 64) has an outer diameter 40-60% smaller than the general diameter of the other portions.
Continues referring to
In some embodiments of the present teachings, the intermediate portion (72), and/or proximal portion (70) of the inner wire (40) is made by removing material from a typical guide wire known by those with ordinary skill in the field. Methods of removing material from the guide wire include grinding, milling, and etc.
In some embodiments, the distal portion (74) of the inner wire (40) may be straight (e.g., 0 degrees) as illustrated in
Now referring to
According to some embodiments, the device penetrates heart tissue with the use of radio frequency energy. Preferably, unipolar electrodes can be used for the inner conductive wire with grounding pads typically placed on the patient's thighs. Alternatively, a bipolar electrode system can be employed as well. The application of radio frequency energy to the inner wire (40) increases the tissue temperature around the distal tip of the inner wire (40) to over 100° C. Mechanical cohesion in the tissue is then diminished, allowing the distal portion of the inner wire (40) to advance as pressure is applied to the tissue by a clinician from the proximal end of the device. In an alternative embodiment, any other methods producing heat (e.g., such as electrical resistance, laser, or ultrasound) can also be used. In some embodiments, the incision is created slowly to reduce the risk of accidental puncture of tissue elsewhere.
Now referring to
According to one embodiment of the present teachings, a delivery sheath is directed into the aorta, through the aortic valve and into the left ventricle between the cordae tendonae. This delivery sheath is then used as a conduit for the tissue piercing device (10) to be delivered to the treatment site. One skilled in the art should understand, a delivery sheath may not be necessary, and thus the tissue piercing device (10) can be directly advanced to the treatment location.
a illustrates a tissue piercing device (10) being delivered to the mitral annulus (2). According to certain embodiments of the present teachings, a tissue piercing device (10) is in its delivery profile where the distal end (32) of the tissue piercing wire (14) is constrained within the delivery catheter (12) and the distal end (32) of the tissue piercing wire (14) is inside the lumen of the delivery catheter (12). In one embodiment of the present teachings, the tissue piercing device (10) advances through the longitudinal lumen of the delivery sheath and aligns below the mitral annulus (2). In some embodiments, the tissue piercing device (10) has a deflectable tip to allow more accurate and easier manipulation and location of the tip of the device relative to the annulus (2). The tip of the tissue piercing device (10) can include a radiopaque marker so that the device may more easily be visualized by using radiographic imaging equipment such as with x-ray, magnetic resonance, ultrasound, or fluoroscopic techniques.
In various embodiments of the present teachings, a tissue piercing wire (14) is pre-loaded within the lumen (26) of a delivery catheter (12) during advancement of the delivery catheter (12) to the treatment site. In various other embodiments, the tissue piercing wire (14) is advanced separately after the delivery catheter (12) is placed at the treatment location.
Referring to
In some embodiments, movement of a tissue piercing wire (14) is accomplished manually. Alternatively, movement of a tissue piercing wire (14) may be automated and therefore requires additional controls such as a spring-loaded mechanism, attached to the delivery. Such embodiments are easier for clinician to manipulate and safer for the patient.
The method for tissue piercing described herein is advantageous over the conventional methods. For example, when using the devices and methods of the present teachings, if the distal tip (32) of the wire (14) inadvertently contacts the left atrial free wall (not shown), the floppiness of the distal portion (64) of the conductive inner wire (40), caused by the bendability intermediate portion (62), would not result in damage to or perforation of the left atrial free wall. Another advantage of the transeptal puncture devices (10) described herein is the ability of the device to pierce through thick tissues.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present teachings belong. Methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present teachings. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
The present application claims the benefit of U.S. patent application Ser. No. 61/747,196, filed Dec. 28, 2012, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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61747196 | Dec 2012 | US |