Patent Application
20120239069
The present disclosure is related to vascular access. More specifically, the disclosure relates to devices and methods for traversing tissue areas including, for example, an inter-atrial septum for transseptal procedures.
Minimally invasive surgical techniques are known for performing medical procedures within all parts of the cardio-vascular system. Exemplary known procedures include the steps of passing a small diameter, highly-flexible catheter through one or more blood vessels and into the heart. When positioned as desired, additional features of the catheter are used, in conjunction with associated equipment, to perform all or a portion of a medical treatment, such as vessel occlusion, tissue biopsy, or tissue ablation, among others. It is often required to create a perforation in the atrial septum to gain access to the left side of the heart during angioplasty, tissue ablation, and other diagnostic and therapeutic procedures to study or treat electrical or morphological abnormalities.
Transseptal puncture devices are used by physicians who perform these specialized cardiology procedures on the left atrium of a heart. Historically in these instances, a needle such as the transseptal needle sold by Medtronic/AVE under the tradename “Brockenbrough®” is used. The needle is made of a stiff metal cannula, and has a sharpened distal tip. The needle is introduced through a guiding sheath in the femoral vein and advanced through the vasculature into the right atrium. From there the needle tip is positioned at the fossa ovalis, the preferred location on the septum for creating a perforation. Once in position, the operator applies force at the proximal end of the needle and uses mechanical energy to advance the needle through the septum and into the left atrium. Once in the left atrium the needle can be attached to an external pressure transducer and the operator can confirm a left atrial pressure before continuing with the procedure. Examples of subsequent steps may include advancing the guiding sheath over the needle and into the left atrium to provide access for other devices to the left heart, or using another device to enlarge the hole made by the needle if a shunt is desired.
In such cardiology procedures, it is also often required to advance a guidewire through to the left atrium. As such, an exchange is performed whereby the operator removes the needle from the guiding sheath and advances the guidewire in its place.
The needles used in this procedure are generally required to be very stiff to enable the desired perforation of the septum wall. The force applied by the needle usually causes the septum to tent, or buckle, before it perforates the tissue. In addition, the amount of force required to perforate the septum varies with each patient. Once the needle makes the perforation, the needle may have significant forward momentum, which can be difficult to control. As such, an unintended consequence of this structure is that the stiff needle can cause damage to the cardiac tissue during advancement of the needle through the vasculature or in the perforation procedure.
Therefore, what is needed is a low-cost, easy to use transseptal puncturing device and methods of use thereof that address the drawbacks of current devices and methods.
The disclosure provides a device for creating a perforation in material of a patient, including in particular, material that comprises the interatrial septum. Among other things, the device facilitates the simplification of procedures requiring transseptal access by eliminating the need for exchange of a needle for a guidewire and improving maneuverability of the device. The disclosure seeks to provide a device that is associated with a decreased risk of unintentional injury to other areas of the heart.
In accordance with the foregoing, there is provided a device for creating a puncture in material within a patient. The device comprises an elongate member having a handle at the proximal region. The device includes a dual lumen structure comprising a central lumen and an offset lumen. The central lumen has a proximal opening at a proximal end and a distal opening at a distal end of the elongate member. The offset lumen extends partially through a longitudinal length of the tubular body and is coextensive at least in part with the central lumen. A first opening is provided at the distal end of the offset lumen with the first opening being in fluid communication with the central lumen to thereby terminate the offset lumen within the longitudinal length of the tubular body.
According to aspects of this disclosure, the device integrates a puncturing needle into the dual lumen elongate tube. The extension of the needle beyond a distal endface of the elongate tube may be limited by an actuator coupled in the handle of the device.
In an alternative aspect of this disclosure, the device may comprise a vacuum port for coupling the proximal opening to a vacuum source. The central lumen may be configured at the proximal region for fluid communication with the vacuum source and configured at the distal region for fluid communication with an environment about the distal region. The vacuum source applies a suction force through the central lumen to the distal endface and thereby pulls tissue adjacent the distal endface proximally in relation to the device.
A method for accessing the heart of a patient is also provided; including positioning a transseptal device proximate to a septal wall, the transseptal device including a central lumen and an offset lumen and the transseptal device further including a needle movably disposed within the offset lumen.
In an embodiment, the method comprises the steps of inserting the transseptal device into a vessel of a patient towards a right atrium of the heart. In accordance with embodiments of the present disclosure, the needle and steering element are located simultaneously in the transseptal device. In some examples, there is the step of threading a steering element through the transseptal device. In other examples, the steering element is preloaded in the transseptal device. Next, the transseptal device is moved with the needle disposed therein to the puncture site at the right atrium such as the inter-atrial septum wall. The needle is then advanced from the offset lumen into the central lumen and out through the distal endface opening of the transseptal device. Next, the septum wall is punctured by further advancing the needle through to the left atrium of the heart. The method may include engaging at least a portion of the septal wall with the transseptal device prior to creation of the opening, where the engagement includes the application of a suction force through at least one of the lumens.
The foregoing summary information is intended to merely illustrate some of the aspects and features of the present disclosure and is not meant to limit the scope in any way. In fact, upon review of the foregoing and the following described and depicted embodiments, one of skill in the art will surely recognize insubstantial modifications or extensions of the disclosure each of which is expressly intended to be covered hereby.
The following drawings are illustrative of particular embodiments of the present disclosure and therefore do not limit the scope of the disclosure. The drawings (not to scale) are intended for use in conjunction with the explanations in the following detailed description, wherein similar elements are designated by identical reference numerals. Moreover, the specific location of the various features is merely exemplary unless noted otherwise.
The following detailed description is merely exemplary in nature and is not intended to limit the disclosure or the application and uses of the disclosure. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
The devices and methods of this disclosure may be used within body lumens, chambers or cavities of a patient for diagnostic or therapeutic purposes such as, for example, in procedures where access to internal body regions is to be achieved through the vascular system or other vessels without complex invasive surgical procedures. For example, the devices and methods described may, for example, be used to create a puncture in the fossa ovalis region of the atrial septum during the diagnosis or treatment of heart conditions. While the exemplary implementations described herein are presented as they may be used in conjunction with diagnosis or treatment of heart conditions, they may also have application in the diagnosis or treatment of conditions in other regions or organs of the body such as the prostate, liver, brain, and gall bladder.
Features or configurations of the devices or steps of the present disclosure enable simplification and efficiency in the creation of a transseptal puncture. The device integrates a puncturing needle into a dual-lumen elongate tube. It is to be understood that references to puncture or puncturing a material, such as tissue, in relation to the present disclosure includes piercing, perforating, cutting, ablating, coagulating, removing material and creating a hole.
The objects, such as needles, used in conjunction with the devices and methods of the disclosure to create a puncture are generally desired to be relatively sharp. These objects may come into contact with other surfaces, including the wall of an associated elongate tube such as a dilator, to cause skiving of particles from the elongate tube. Protection against contact between the adjacent objects helps to reduce the production of skived particles. Several examples of the devices and methods of this disclosure contribute to a reduction of the occurrences of skiving.
Alternatively, the introduction of a distal portion 102 of the transseptal device 100 into the right atrium RA is also suggested by passage of the distal portion into the right atrium RA through the superior vena cava SVC.
As shown in
Regarding fabrication techniques for elongate tube 102, the proximal portion 104 and the distal portion 106 may be integrally formed from a biocompatible material having requisite strength and flexibility for deployment within heart 10. Appropriate materials can be comprised of a biocompatible polymer as well as other known biocompatible materials including polyamides. The elongate tube 102 can be injection molded from a material having a relatively high modulus of elasticity, yet being sufficiently elastic and not prone to brittle fracture, for example 75D durometer polyurethane or high density polyethylene or polyamide. Alternately, one or both of the proximal portion 104 and the distal portion 106 can be insert-molded or formed by molding or an extrusion process. According to some embodiments, portions can be wholly or partially formed from a metal having suitable elastic and elastomeric properties, examples of which include, but are not limited to, titanium alloys, Ni—Ti super-elastic alloys and stainless steel and the like. Other suitable materials known in the art can also be used. In another embodiment, the proximal portion 104 and the distal portion 106 can be individually fabricated.
The proximal portion 104 and the distal portion 106 are preferably flexible, so as to facilitate desired articulation during use. In general terms, however, the elongate tube 102 defines a longitudinal axis L1. It should be recognized that in one position, the longitudinal axis L1 extends linearly from the proximal portion 104 to the distal portion 106. Upon deployment, it may be that the distal portion 106 is forced to an arcuate, curved or curvilinear orientation. With this in mind, the distal portion 106 may have a curvilinear shape that is pre-formed in a plane transverse to the longitudinal axis L1. To this end, at least part of the distal portion 106 preferably extends in a generally arcuate fashion. In other examples, various configurations of the distal portion of the elongate tube 102 including linear, curvilinear or complex distal portions may be employed according to the present disclosure.
Regardless of the exact shape, the distal portion 106 preferably orients the distal endface 110 toward the atrial septum as described in conjunction with
Alternatively, a delivery catheter (not shown) may be employed for delivering the elongate tube 102. The delivery catheter will slidably receive the elongate tube 102. Prior to deployment, the distal portion 106 would be retracted within the delivery catheter, rendering the pre-shaped portion straight. Upon deployment from the delivery catheter, the distal portion 106 would take on the preformed shape. Any other approaches known in the art for providing and delivering preformed devices are similarly acceptable.
A portion of the distal portion 106 may be tapered or otherwise define a gradually narrowing profile, in relation to the proximal portion 104, towards the distal endface 110 of the elongate tube 102. Tapering the distal portion 106 will facilitate maneuvering of the elongate tube 102 through the tortuous vasculature to a targeted puncture site.
The elongate tube 102 may be coupled at its proximal end 104 through, for example, a positive locking mechanism (such as a snap fit) to handle 112 used to manipulate and position the transseptal device 100. The exemplary handle 112 may be sized to be grasped by a user and includes a port 114. Port 114 includes a channel that is in fluid communication with a channel of the handle 112 such that both channels are in fluid communication with one or both lumens 120, 122. The handle 112 will typically be formed from inert plastics or other materials that are suitable to medical applications. Specifically, the handle may be formed from any suitable material such as plastics, polymers, non-ferrous metals such as gold or copper, or a mixture thereof.
An actuator 116 which is connected to handle 112 may be used to advance a needle (
In other embodiments, actuator 116 may be formed as a wheel that is rotated about an axis to impart lateral movement of the needle 128. In such an embodiment, the rotational distance would translate into the lateral length over which the needle 128 is extended. In either configuration, the actuator 116 will serve to indicate to a user the length to which the needle has been extended. In addition to this benefit, the assembly of the transseptal device 100 having handle 112 and incorporating a puncturing needle facilitates a one-handed manipulation of the device 100 of the present disclosure. This aspect facilitates ease of use and simplifies the puncturing procedure.
As is further illustrated in
Central lumen 120 may also be used for injection of a fluid medium that may be delivered through distal endface 110 to a surrounding environment. As is known in the art, such fluid delivery may include isotonic saline solution to form so-called virtual electrode regions, marker dye or other material that is advantageously dispensed in, on or near a cardiac tissue location.
A needle 128 may be preloaded, or positioned, in the offset lumen 122. The needle 128 can take a number of configurations. One such needle 128 is a transseptal needle such as the Brockenbrough® needle discussed above. Another example is a hollow, substantially cylindrical needle element that may be formed from hypotubes. In addition to hypotubes, needle elements may be formed from a reinforced plastic, a pultruded material, a glass or carbon reinforced plastic, reinforced ABS, or high impact ABS or any other plastic material capable of maintaining a sharp tip and transmitting the force required for a given puncturing application. Other configurations include solid access or puncture devices, and hollow tube elements having side access ports at the distal end portions which allow fluid to exit at least one side of the needle element. Hollow needle elements also permit the monitoring of blood pressure within the right and left atria. As is known, the blood pressure within the left and right atrium is substantially different, and this fact can be used as evidence to confirm that a successful puncture of the atrial septum has been performed. However, the disclosure is not limited to any particular type of needle and any suitable element that can function to puncture material in a patient may be used.
With continued reference to
Central lumen 120 may be relatively constant in cross-sectional area over the entire length of tube 102 or, in other embodiments over, a majority of the length of tube 102. When formed with varying cross-sectional areas, the distal portion of the central lumen 120 terminating at the distal endface 110 may be configured with an area that will permit both the steering element 126 and the needle 128 to contemporaneously reside therein and be withdrawn through the distal endface 110 opening. The central lumen 120 may be centralized within the elongate tube 102 parallel to longitudinal axis L1 (shown in
In order to be suitable for its intended purpose, the needle 128 typically includes a sharp distal end to enable the puncturing that will make easier entry into tissue or other material on which the needle 128 is to be used. By preloading the needle 128 in the offset lumen 122, movement of the sharp tip of needle 128 is limited to the extension imparted by actuator 116. The presence of both the central lumen 120 and the offset lumen 122 permits the contemporaneous disposition of both the needle 128 and the steering element 126 within the elongate tube 102. This eliminates the requirement for the exchange of needle 128 with steering element 126 as is the case with the conventional devices that permit only one or the other of either steering element 126 or needle 128 to be in the device 100 at one time. Moreover, preloading of needle 128 within offset lumen 122 and the limiting of the movement within the lumen 122 facilitates the reduction or elimination of skiving of particles from the elongate tube 102.
In an embodiment, a vacuum source (not shown) may be connected to elongate tube 102 via the port 114 on handle 112. The port 114 is in fluid communication with the central lumen 120. As such, when a vacuum source is connected to the port 114 at least a partial vacuum is established within the central lumen 120 of the elongate tube 102. The application of a vacuum or suction to the targeted tissue by the device 100 aids in both tensioning the tissue to allow easier penetration by needle 128 as well as preventing the pierced tissue from “tenting” or extending outward from the opposite side of the tissue wall 120 (into the left atrium, for example), thereby decreasing the likelihood of any complications or unintended trauma to surrounding tissue structures from the tissue penetration. Once the tissue has been crossed or otherwise pierced, the vacuum/suction application may be discontinued.
Referring to
In alternative embodiments, a vacuum supply source connected to the port 114 of handle 112 may be energized prior to advancing the needle 128. Energizing the vacuum supply source will evacuate air from the central lumen 120 of elongate tube 102 which is in contact with the cardiac tissue adjacent the fossa ovalis. The suction force releasably secures the procedure site of the fossa ovalis. The needle 128 will create a puncture in the septum wall while the septum is held fast against the elongate tube 102 by the vacuum created by the vacuum supply source. The action of the vacuum holding fast the septum during creation of the puncture may aid with minimizing deflection (or tenting) of the tissue in proximity to the puncture. After the hole is created in the septum wall 14, and with needle 128 in the fully advanced position, the vacuum system is deactivated.
Turning next to
While the present disclosure has been described in terms of certain exemplary preferred embodiments, it will be readily understood and appreciated by one of ordinary skill in the art that it is not so limited and that many additions, deletions and modifications to the preferred embodiments may be made within the scope of the disclosure as hereinafter claimed. It should also be understood that the described features, configurations or steps are presently-contemplated examples, but other examples with other features, configurations or steps or combinations thereof may also achieve one or more of the benefits of the present disclosure. Accordingly, the scope of the disclosure is limited only by the scope of the appended claims.
