US20070021767A1 - Steerable endoluminal punch - Google Patents

Abstract

This invention is a transvascularly placed punch, further including internal steerability and the ability to articulate in a direction at right angles to its longitudinal axis at or near its distal end. The punch is generally fabricated from stainless steel and includes an outer tube, an intermediate tube, a central stylet, hub structures, and a distal articulating region. The punch can be advanced through a body lumen in its straight configuration and then be selectively articulated or curved to permit negotiation of tortuous curvature or to permit optimal approach or access to a puncture site. The punch is able to create holes in the atrial septum of the heart or other structures and is easier to use than punches that are pre-curved near their distal tip since it is easier to advance through accessory catheters.

Description

PRIORITY CLAIM
• This application claims priority benefit under 35 USC § 119(e) from U.S. Provisional Application No. 60/702,239, filed Jul. 25, 2005, entitled STEERABLE ENDOLUMINAL PUNCH, the entire contents of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
• The invention relates to devices and methods for performing endovascular access to the cardiovascular system or other body vessels or body lumens, especially procedures performed in the fields of cardiology, radiology, electrophysiology, and surgery.
BACKGROUND OF THE INVENTION
• During certain interventional procedures that are directed at cardiac access, the patient is catheterized through an access point in a vein or artery. A catheter is routed to the heart or other region of the cardiovascular system through the access point, which may be created by a cutdown or a percutaneous access procedure. The catheter may be routed to a target location within the heart, cerebrovasculature, or other region of the cardiovascular system. In certain cases, it becomes necessary to create a hole in a cardiovascular structure so that catheters or devices can be routed through a wall so as to provide for placement on the other side of the wall. One such case is the need to punch a hole in the septum that divides the right atrium of the heart from the left atrium. Such atrial septal punctures are increasingly used to gain access to the left atrium by way of the central venous system and the right atrium. Access to the left atrium of the heart is often useful in therapeutic and diagnostic procedures such as, but not limited to, valve replacement, valve repair, electrophysiology mapping, cardiac ablation, atrial appendage plug placement, and the like.
• The currently accepted procedure for left atrial access involves routing a needle called a Brockenbrough™ needle into the right atrium with the Brockenbrough needle pre-placed within a guiding catheter. The guiding catheter specifically preferred for use with a Brockenbrough needle is called a Mullins™ catheter. The Brockenbrough needle is a long punch formed from a stainless steel wire stylet that is surrounded by a stainless steel tube. The distal end of the stainless steel tube forms a relatively sharp circular punch capable of penetrating certain vascular structures such as the inter-atrial septum. Brockenbrough needle stylets are typically 0.013 to 0.014 inches in diameter while the stainless steel tube is generally between 0.045 and 0.050 inches in outside diameter. The Brockenbrough needle outside diameter is configured to slidingly fit within the central lumen of the Mullins catheter. The stainless steel tube is substantially straight along most of its length but is pre-bent into a curved or “J” shape at its distal end. A loop at the proximal end of the Brockenbrough stylet facilitates grasping of the stylet and performing manual advance or retraction. The current art considers the access to the right atrium from the femoral vein to be relatively straight so the current devices are straight except for the distal curve, which is shaped for the approach to the atrial septal wall.
• The Brockenbrough needle, a relatively rigid structure, is operated by advancing the device, with its stylet wire advanced to blunt the sharp tip, within its guiding catheter through the inferior vena cava and into the superior vena cava. Under fluoroscopic guidance, the Brockenbrough needle, retracted inside the distal tip of the Mullins catheter, is withdrawn caudally into the right atrium until it falls or translates medially into the Fossa Ovalis. The force of the Brockenbrough needle/Mullins catheter assembly pushing against the relatively weak atrial septal wall causes the Fossa Ovalis to become tented toward the left atrium. The Brockenbrough needle, protected by the blunt distal tip of the Mullins catheter, is firmly held against the Fossa Ovalis of the atrial septum. Pressure monitoring and dye injection are carried out through the central lumen of the punch following removal of the stylet wire. The circular or hollow punch is next advanced distally to puncture a hole through the atrial septum. Erroneous placement of the punch can lead to penetration of adjacent structures such as the aorta, damage to which would cause potentially severe hemorrhage and potentially compromise the health of the patient. Thus, extreme care is exercised to verify location prior to the actual punching step. The Brockenbrough needle is next advanced through the atrial septum. The guide catheter, which includes a removable, tapered, distal dilator, having a central lumen for the Brockenbrough needle, is advanced over the Brockenbrough needle system and into the left atrium. The Brockenbrough needle is next removed from the Mullins guide catheter along with the central dilator or obturator.
• A main disadvantage of this system is that the Brockenbrough needle system is pre-curved at its distal end and is relatively rigid. This pre-curving, rigidity, and necessary distal sharpness causes the Brockenbrough needle system to carve material from the interior wall of the otherwise straight guiding catheter when the Brockenbrough needle assembly is inserted therethrough. The material carved from the guide catheter could potentially be released into the cardiovascular system and generate emboli with any number of serious clinical sequelae. Should this embolic catheter material enter the left atrium it could flow into and block important arterial vasculature such as the coronary arteries or cerebrovasculature. Furthermore, advancing a pre-curved, rigid punch through the cardiovascular system is difficult and could potentially damage the vessel wall or any number of significant cardiovascular structures, during the advancement.
• It would be desirable to have a Brockenbrough needle system that was initially straight and then became curved after being inserted into the guiding catheter. Such a straight Brockenbrough configuration would be advantageous during ex-vivo insertion as well as insertion after the guide catheter has already been placed into the cardiovascular system. During ex-vivo insertion, the debris can be flushed from the lumen of the guide catheter but complete removal is not assured and emboli can still be generated by the device. However, if the guide catheter was already inserted into the cardiovascular system, the debris could not be flushed out ahead of time and could easily flow toward or be released into the cardiovascular system with potentially catastrophic or fatal results. Furthermore, the needle or punch could be more easily advanced into the body lumen if it were not pre-curved.
SUMMARY OF THE INVENTIONS
• In an embodiment, the invention is a transvascularly or endovascularly placed tissue punch, with internal delectability or the ability to articulate, at its distal end, in a direction away from its longitudinal axis. The punch can also be termed a catheter, needle, or cannula. The punch is generally fabricated from stainless steel and comprises an outer tube, an intermediate tube, a central stylet wire, and a distal articulating region. The deflecting or articulating mechanism is integral to the punch. The punch, needle, or catheter is sufficiently rigid, in an embodiment, that it can be used as an internal guidewire or internal guide catheter. The punch is useful for animals, including mammals and human patients and is routed through body lumens or other body structures to reach its target destination.
• In an embodiment, the punch comprises an inner core wire or stylet, an intermediate tube and an outer tube. In an embodiment, the stylet can be removable or non-removable. The punch further comprises a hub at its proximal end which permits grasping of the punch and also includes a stopcock or valve to serve as a lock for the stylet, or inner core wire, as well as a valve for control of fluid passage into and out from the innermost lumen within which the stylet or inner core wire resides. The proximal end further comprises one or more control handles to manipulate the amount of articulation at the distal end of the catheter. The proximal end further is terminated with a female luer or luer lock port, which is suitable for attachment of pressure monitoring lines, dye injection lines, vacuum lines, a combination thereof, or the like.
• The punch is fabricated so that it is substantially straight from its proximal end to its distal end. Manipulation of a control mechanism at the proximal end of the punch causes a distal region of the punch to bend or curve away from its longitudinal axis. The bending, steering, or articulating region is located near the distal end of the punch and can be a flexible region or structure placed under tension or compression by pull wires or control rods routed from the control handle at the proximal end of the punch to a point distal to the flexible region. In another embodiment, the bending or articulating mechanism can also be created by pre-bending the outer tube in one direction and bending the intermediate tube in another direction. The two tubes can be rotated relative to each other, about their longitudinal axis, by turning knobs or grips at the proximal end of the punch. When the curvatures of both tubes are aligned, the tubes will generally cooperate and not oppose each other, thus, maximum curvature or deflection is generated. When the tubes are rotated so their natural curvatures are aligned 180 degrees from each other, the curves will oppose each other or cancel out. Thus, the nested tubes will be substantially straight when the curvatures of the two concentric tubes oppose each other. Alignment marks or graduations at the proximal end can be used to assist with proper rotational alignment of the two tubes. The central core wire or stylet is generally straight and flexible and does not contribute to the curvature. In another embodiment, however, the stylet can be imparted with a curvature to assist with steering or articulation. Rotation of the two concentric tubes at relative angles between 180 degrees and 0 degrees will result in intermediate amounts of deflection so the amount of deflection can be increased or decreased in an analog, continuously variable, digital, or stepwise fashion. The stepwise or digital response can be generated using detents or interlocks that weakly engage at specific predetermined locations. A locking mechanism can be further utilized to hold the two tubes in rotational alignment once the desired amount of curvature has been achieved.
• In another embodiment, steerability can be obtained using actuators on the surface or within the interior of the cannula to force bending of the cannula. These actuators can be typically electrically powered. In an embodiment, an actuator can comprise electrical leads, a power source, a compressible substrate, and shape memory materials such as nitinol. Such actuators may be distributed along the length of the cannula. The actuators may be placed so as to oppose each other. Opposing actuators are activated one at a time and not simultaneously and can generate a steering effect or back and forth motion.
• Other embodiments of the inventions comprise methods of use. One method of use involves inserting the central core wire so that it protrude out the distal end of the punch. A percutaneous or cutdown procedure is performed to gain access to the vasculature, either a vein or an artery. An introducer and guidewire are placed within the vasculature and the guidewire is routed proximate to the target treatment site. The introducer can be removed at this time. A guiding catheter, preferably with a central obturator or dilator is routed over the guidewire to the target site. In an embodiment, the target site can be the atrial septum. The guidewire can be removed at this time. The punch is adjusted so that it assumes a substantially straight configuration. The punch can be advanced through the central lumen of the already placed catheter. By making the punch as straight as possible, there is no curvature to force the sharpened distal edges of the punch to scrape the inside of the catheter lumen as the punch is advanced distally inside the guide catheter and potentially dislodge or scythe away debris or material which could cause embolic effects to the patient. Carefully ensuring that the punch does not protrude beyond the distal end of the catheter or its obturator, the punch is next deflected so that it forms a curve. The curve is oriented so that it is medially directed toward the atrial septum. Alignment with any curvature of the catheter can be completed at this time. The punch and guide catheter/obturator are withdrawn caudally, as a unit, into the right atrium. The punch and guide catheter are positioned using fluoroscopy or other imaging system against the Fossa Ovalis. The Fossa Ovalis is a relatively thin structure and the force of the punch will tent the Fossa Ovalis toward the left atrium. In one embodiment, the central core wire or stylet, initially advanced, can next be withdrawn to expose the sharp distal edge of the punch. When correctly positioned under fluoroscopy, ultrasound, or other imaging system, dye can be injected into the central lumen of the punch at its proximal end and be expelled out of the distal end of the punch and obturator to paint or mark the Fossa Ovalis. A generally “V-shaped” mark can be observed under fluoroscopy, which denotes the location of the Fossa Ovalis. The curvature of the punch can be increased or decreased by articulation to gain optimal alignment with the Fossa Ovalis. This steering function can be very beneficial in device placement.
• Maintaining the position of the guiding catheter against the Fossa Ovalis, the punch is advanced distally against and through the atrial septum, in the region of the Fossa Ovalis, so that it penetrates and protrudes into the left atrium. In order to stabilize the atrial septal tissue prior to coring, a distally protruding corkscrew tipped wire or a vacuum head operably connected to the proximal end of the punch, can be used to grasp and retract the septal tissue. Once the initial penetration is completed, the guide catheter is next advanced, with its tapered obturator leading the way, across the atrial septum until it resides within the left atrium. The tapered obturator or dilator along with the punch can be removed at this time to allow for catheter placement through the guiding catheter. In another embodiment, a calibrated spacer can be used between the guide catheter hub and the punch hub to ensure that the punch does not protrude beyond the distal end of the guide catheter tip until the desired time for punching the hole. At this point, the spacer is unlocked and removed from the punch or catheter.
• In another embodiment, the core wire or stylet is sharpened and serves as a tissue punch. In this embodiment, the distal end of the hollow tubes of the punch are blunted and made relatively atraumatic. Once the core wire punch has completed tissue penetration, the outer tubes are advanced over the central punch wire through the penetration and into the left atrium. In another embodiment, a pressure monitoring device such as a catheter tip pressure transducer, or a pressure line terminated by a pressure transducer, can be affixed to a quick connect, generally a luer fitting, at the proximal end of the punch hub. By monitoring pressure, it is possible to determine when the distal end of the punch has passed from, for example, the right atrium into the left atrium, because the pressure versus time curves in these two chambers are measurably, or visually, different. The proximal end of the hub further has provision for attachment to a dye injection line for use in injecting radiographic contrast media through the central lumen of the punch. Typically a manifold can be attached to the luer fitting on the proximal end of the hub, the manifold allowing for pressure monitoring, for example on a straight through port, and for radiopaque dye injection, for example through a side port. A stopcock, or other valve, can be used to control which port is operably connected to the central lumen of the punch.
• For purposes of summarizing the invention, certain aspects, advantages and novel features of the invention are described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. These and other objects and advantages of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• A general architecture that implements the various features of the invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention. Throughout the drawings, reference numbers are re-used to indicate correspondence between referenced elements.
• FIG. 1 illustrates a side view of a trans-septal punch assembled so that the intermediate tube is bent in a direction 180 degrees opposite that of the outer tube, resulting in a substantially straight punch configuration;
• FIG. 2 illustrates a side view of the disassembled trans-septal punch showing the central core wire or stylet, the intermediate tube bent in one direction and the outer tube bent in another direction;
• FIG. 3 illustrates a side view of the trans-septal punch assembled so that the intermediate tube bend is aligned in the same direction as the outer tube bend, resulting in a curved distal end on the punch assembly;
• FIG. 4 illustrates a side view of a trans-septal punch comprising a flexible region proximal to the distal end and pull-wires disposed between the distal end and the proximal end of the punch;
• FIG. 5 illustrates a side view of the trans-septal punch ofFIG. 4 wherein one of the pull-wires is placed in tension causing the distal flexible region of the punch to deflect into an arc away from the longitudinal axis of the punch;
• FIG. 6 illustrates an adjustable, spacer, which sets and maintains the distance between the distal end of the punch hub and the proximal end of a guide catheter hub.
DETAILED DESCRIPTION OF THE INVENTION
• In accordance with current terminology pertaining to medical devices, the proximal direction will be that direction on the device that is furthest from the patient and closest to the user, while the distal direction is that direction closest to the patient and furthest from the user. These directions are applied along the longitudinal axis of the device, which is generally an axially elongate structure having one or more lumens or channels extending through the proximal end to the distal end and running substantially the entire length of the device.
• FIG. 1 illustrates a side view of a punch, needle, orcatheter assembly100, with an integral articulating or bending mechanism. Thepunch assembly100 comprises a stylet orobturator wire102, anintermediate tube104, anouter tube106, anobturator grasping tab108, astopcock110, anintermediate tube pointer112, anouter tube pointer114, anintermediate tube hub116, and anouter tube hub118.
• Referring toFIG. 1, theobturator wire102 is affixed to theobturator grasping tab108. The stylet orobturator wire102 is inserted through the central lumen of theintermediate tube104 and is slidably disposed therein. Thestopcock110 is affixed to theintermediate tube hub116 and the through lumen of thestopcock110 is operably connected to the central lumen of theintermediate tube104. Theintermediate tube pointer112 is affixed to the intermediate tube hub so that it is visible to the user. Theouter tube pointer114 is affixed to theouter tube hub118 so that it is visible to the user. Theintermediate tube hub116 and theintermediate tube104 are able to rotate about the longitudinal axis within theouter tube hub118 and theouter tube106. In an embodiment, theintermediate tube104 is restrained from longitudinal motion relative to theouter tube106. In another embodiment, theintermediate tube104 can be advanced distally relative to theouter tube106. In this latter embodiment, advancement of theinner tube104 can be used to facilitate punching. The distal end of theintermediate tube104 can be sharpened and serve as a punch. The distal end of theintermediate tube104 is sheathed inside theouter tube106 to protect the tissue from the sharp distal edge of theintermediate tube104 until theintermediate tube104 is advanced distally outside the distal end of theouter tube106. A releaseable lock can be used to maintain the axial or longitudinal position of theintermediate tube104 relative to theouter tube106 until punching is required. A releaseable lock can further be used to maintain the rotational position of theintermediate tube hub116 and thus theintermediate tube104 relative to theouter tube hub118 and theouter tube106.
• All components of thepunch assembly100 can be fabricated from metals such as, but not limited to, stainless steel, Elgiloy™, cobalt nickel alloy, titanium, nitinol, or the like. The nitinol can be shape-memory or it can be superelastic. The metals used in theobturator wire102, theintermediate tube104 and theouter tube106 are advantageously cold rolled, heat treated, or otherwise processed to provide a full spring hardness. Theintermediate tube104, theouter tube106, or both, are relatively rigid, resilient structures. Polymeric materials, such as, but not limited to, polycarbonate, ABS, PVC, polysulfone, PET, polyamide, polyimide, and the like, can also be used to fabricate thestopcock110, theintermediate tube hub116, theouter tube hub118, theintermediate tube pointer112, and theouter tube pointer114. The materials are beneficially radiopaque to maximize visibility under fluoroscopy during the procedure. Additional radiopaque markers fabricated from tantalum, platinum, iridium, barium sulfate, and the like can be added to improve visibility if needed. Theintermediate tube104 is curved or bent near its distal end into a gentle curve, preferably with a radius of between 1 to 5 inches and so that the distal tip is deflected through an angle of approximately 10 to 90 degrees from the longitudinal axis of theintermediate tube104. Theouter tube106 is curved or bent near its distal end into a gentle curve, preferably with a radius of between 1 to 5 inches and so that the distal tip is deflected through an angle of approximately 10 to 90 degrees from the longitudinal axis of theouter tube106. Theintermediate tube hub116 is welded, silver soldered, bonded, crimped, or otherwise fastened to the proximal end of theintermediate tube104 so that theintermediate tube pointer112 points in the direction of the bend in theintermediate tube104. Theouter tube hub118 is welded, silver soldered, bonded, crimped, or otherwise fastened to the proximal end of theouter tube106 so that theouter tube pointer114 points in the direction of the bend in theouter tube106. When theintermediate tube pointer112 is oriented 180 degrees away from the direction of theouter tube pointer114, the bend in theintermediate tube104 substantially counteracts or opposes the bend of theouter tube106 and thecoaxial assembly100 is substantially straight, as shown inFIG. 1. Thestopcock110 can also be a ring seal, Tuohy-Borst valve, membrane valve, hemostasis valve, gate valve, or other valve, generally, but not necessarily manually operated. The stiffness of theintermediate tube104 and theouter tube106 are sufficient that the punch can be used as a guide for other catheters through which thepunch100 is passed.
• FIG. 2 illustrates a side view of a stylet orobturator140 further comprising theobturator wire102 and the obturator-graspingtab108. Theobturator wire102 is blunted at its distal end to render it as atraumatic as possible. In another embodiment, theobturator wire102 can be tapered in diameter to render it very flexible and therefore atraumatic at its distal end. Theobturator wire102, in another embodiment, can be sharpened and serve as a needle or primary punching mechanism.FIG. 2 also illustrates anintermediate punch assembly120 further comprising theintermediate tube104, thestopcock110, theintermediate tube pointer112, theintermediate tube hub116, anintermediate tube seal124, an intermediatetube pointer ball126, a throughlumen port128, a beveleddistal tip132, and apre-set curve136.FIG. 2 further illustrates anouter tube assembly122 further comprising theouter tube106, theouter tube hub118, theouter tube pointer114, an outer tubedistal curve130, and an outertube pointer ball134.
• Referring toFIG. 2, the obturator-graspingtab108 is affixed, either integral to, silver soldered, welded, crimped, adhered, pinned, or otherwise attached, to the proximal end of theobturator wire102. Theintermediate tube104 is affixed to theintermediate tube hub116 by silver soldering, welding, potting, crimping, setscrew, pin, or other fixation method, such that thehub116 rotates 1 to 1 with theintermediate tube104. An optional intermediatetube pointer ball126 is affixed to theintermediate tube pointer112 and provides additional visual and tactile rotational positioning sense for the intermediate punch orneedle assembly120. A curve or bend136 is heat set, or cold worked into theintermediate tube104 at or near its distal end. The distal end of theintermediate tube104 comprises abevel132 which helps serve as a punch or cutting edge for theintermediate tube104. The angle of thebevel132 can range between 20 and 70 degrees from the direction perpendicular to the longitudinal axis of theintermediate tube104. In another embodiment, the bevel is removed and the distal tip of theintermediate tube104 is a gentle inward taper or fairing moving distally that serves as a dilator should theobturator wire102 be used as the punching device rather than the blunt distal tip obturator of theintermediate tube104. Theintermediate tube hub116 further comprises a circumferential groove with an “O”ring124 affixed thereto. The “O”ring124 serves to form a fluid (e.g. air, blood, water) tight seal with the inner diameter of theouter sheath hub118 central lumen and allows for circumferential rotation of theintermediate tube hub116 within theouter tube hub118. The “O”ring124 is fabricated from rubber, silicone elastomer, thermoplastic elastomer, polyurethane, or the like and may be lubricated with silicone oil or similar materials. Thestopcock110 can be a single way or a three-way stopcock without or with a sideport, respectively.
• Theouter punch assembly122 comprises thebend130, which is heat set or cold worked into theouter tube106 in the same longitudinal location as thebend136 of the intermediate tube. The wall thicknesses of theintermediate tubing104 and theouter tubing106 are chosen to provide bending forces that cancel out when thecurves136 and130 are oriented in opposite directions and theintermediate tubing104 is inserted fully into theouter tubing106. The wall thickness of theouter tube106 and theintermediate tube104 can range between 0.003 inches and 0.20 inches, preferably ranging between 0.004 and 0.010 inches. The outer diameter of theouter tube106 can range between 0.014 and 0.060 inches and preferably between 0.025 and 0.050 inches. The outer diameter of theobturator wire102 can range between 0.005 and 0.030 inches and preferably range between 0.010 and 0.020 inches.
• FIG. 3 illustrates a side view of thepunch assembly100 fully assembled and aligned so that both the intermediate tube distal curve136 (Refer toFIG. 2) and the outer tubedistal curve130 are aligned in the same direction resulting in a natural bend out of the axis of thepunch100. Thepunch assembly100 comprises theobturator wire102, theintermediate tube104, theouter tube106, theobturator grasping tab108, thestopcock110, theintermediate tube pointer112, theouter tube pointer114, theintermediate tube hub116, the intermediatetube pointer ball126, and the outertube pointer ball134.
• Referring toFIG. 3, theouter tube pointer114 andintermediate tube pointer112 are aligned together and in this configuration, the tubing assembly possesses its maximum curvature, which is oriented in the same directions as thepointers112 and114. Thepointer balls126 and134 are aligned together to provide additional tactile and visual indices of curvature direction. In an embodiment, the curvature of thetube assembly104 and106 is unbiased with no net force exerted therebetween and an angle of approximately 45 degrees is subtended by the device in the illustrated configuration. Further curvature can also occur out of the plane of the page so that the curvature takes on a 3-dimensional shape, somewhat similar to a corkscrew. In another embodiment, the curvature of the alignedinner tube104 and theouter tube106 subtends an angle of 90-degrees or greater. Again, theintermediate tube104 and theouter tube106 have stiffness sufficient that the assembly is capable of guiding any catheter through which thepunch100 is passed. In another embodiment, theintermediate tube104 and theouter tube106 have different degrees of curvature so that when they are aligned, a net force still is generated between the two tubes, although a maximum curvature configuration is still generated. This embodiment can be advantageous in permitting articulation in a direction away from the direction of primary curvature. The radius of curvature of thepunch100 can range from substantially infinity, when straight, to as little as 0.5-cm, with a preferred range of infinity to as little as 2-cm radius when fully curved or articulated. One embodiment permits a substantially infinite to a 3-cm radius of curvature. The overall working length of the punch, that length from the proximal end of the outer tube hub to the distal most end of the punch, can range from 10 to 150-cm and preferably between 60 and 100-cm, with a most preferred range of between 70 and 90-cm. A preferred curve has a radius of about 3-cm and is bent into an arc of about 45 to 90 degrees.
• FIG. 4 illustrates a side view of another embodiment of a needle or punchassembly400 comprising anobturator wire102, an obturatorwire grasping tab108, astopcock110, anintermediate tube404, anouter tube406, a plurality of deflectingwires412, anouter tube hub414, a deflectinglever416, aweld420, anaxis cylinder424, a plurality of deflectingwire channels426, and aflexible region430. The distal end of the region just proximal to theflexible region430 is shown in breakaway view. Furthermore, the distal end of the region just proximal to theflexible region430 as well as theflexible region430 has been expanded in scale so that certain details are more clearly visible.
• Referring toFIG. 4, theflexible region430 is affixed to theouter tube406 by aweld420. Theflexible region430 can also be fixed to theouter tube406 by a crimp, pin, setscrew, adhesive bond, interference fit, mechanical interlock, thread, or the like. The attachment between theflexible region430 and theouter tube406 is made at the proximal end of theflexible region430 and a second attachment orweld420 can be made at the distal end of theflexible region430 so as to attach to a length of distalouter tube406. Theflexible region430 can comprise a length of coiled wire such as that used in guidewires, it can be a tube that comprises cutouts to provide a backbone configuration to impart flexibility, it can be a length of polymeric tube with elastomeric characteristics, or it can be another type of structure that is known in the art as providing flexibility. These preferred structures also advantageously provide column strength and kink resistance to theflexible region430. The center of theflexible region430 is hollow and comprises a lumen, which is operably connected to the central lumen of theouter tube406 at both the proximal and distal end of theflexible region430. Thestopcock110 is affixed, at its distal end, to theouter tube hub414. Theouter tube hub414 further comprises a deflectinglever416 that is affixed to theaxis cylinder424, which serves as an axle or rotational pin, and can be moved proximally or distally by manual action on the part of the operator or by a motor or other electromechanical actuator (not shown). The deflectinglever416 is operably connected to the proximal ends of the deflectingwires412. In an exemplary embodiment, one of the deflectingwires412 is affixed to the top of theaxis cylinder424 and the other deflecting wire is affixed to the bottom of theaxis cylinder424. When the deflecting lever is pulled proximally, for example, thetop wire412 is placed under tension and the tension on the bottom wire is relieved causing tension to be exerted on the distal end of thepunch400. The deflectingwires412 are slidably routed through thedeflecting wire channels420 within theouter tube406. The deflectingwires412 also run through thedeflecting wire channels420 within theflexible region430. The deflectingwires412 can also be routed through the internal lumen of theouter tube406 and theflexible region430.
• Referring toFIG. 4, theouter tube hub414 is affixed to the proximal end of theouter tube406 by a crimp, pin, setscrew, adhesive bond, interference fit, mechanical interlock, thread, or the like. Theintermediate tube404 is affixed to the distal end of theouter tube406 by a crimp, pin, setscrew, adhesive bond, interference fit, mechanical interlock, thread, or the like. In another embodiment, theintermediate tube404 is routed throughout the length of theouter tube406. In this embodiment, the intermediate tube can comprise grooves (not shown) that serve as deflectingwire channels420 when theintermediate tube404 is inserted inside theouter tube406. Such grooves can also be disposed on the interior surface of theouter tube406, rather than on the exterior surface of theinner tube404. Theobturator wire102 and the attached graspingloop108 are slidably disposed within the inner lumen of theouter tube406, or theintermediate tube404. Theintermediate tube404 is gently tapered up to theouter tube406 at the distal end of theouter tube406 in a transition region so that a dilator effect can be created during distal advancement of thepunch400. The distal end of theintermediate tube404 can comprise a bevel132 (FIG. 2) or other sharp point for punching through biological tissue. The distal end of theintermediate tube404 preferably forms a non-coring needle or punch that does not excise a tissue sample. The non-coring punch feature is achieved by keeping the central lumen closed or very small. Thenon-coring punch400 embodiment can comprise filling the lumen of theintermediate tube404 with the obturator orstylet wire102 to prevent the sharp edge of the intermediate tube from functioning as a trephine.
• FIG. 5 illustrates a side view of thepunch assembly400 wherein the deflectinglever416 has been withdrawn proximally causing increased tension in one of the deflectingwires412, causing theflexible region430 to bend422 out of the longitudinal axis. Thepunch assembly400 further comprises theobturator wire102, the obturatorwire grasping tab108, thestopcock110, the deflectinglever416, anaxis cylinder424, thehub414, theouter tubing406, theintermediate tubing404, and thebend422.
• Referring toFIG. 5, the deflectinglever416 has been moved proximally and theaxis cylinder424 causing thetop deflecting wire412 to be placed in tension while thebottom deflecting wire412 is relaxed. The deflectingwires412 are affixed at their distal end to theouter tubing406 or theintermediate tubing404 at a point substantially at or beyond the distal end of theflexible region420. The distal fixation point (not shown) of the deflectingwires412 is off-center from the axis of theouter tubing406 orintermediate tubing404. When uneven tension is created in the opposing deflectingwires412, the uneven tension on the distal end of thepunch400 causes thebendable region430 to undergo deflection into a curve or bend422. Similarly, forward movement of the deflectinglever416 will place thebottom deflecting wire412 in tension while theupper deflecting wire412 will be relaxed, causing thepunch400 to undergo a bend in the opposite direction (downward). The deflectinglever416 can further comprise a ratchet and lock, a friction lock, a spring-loaded return, or other features to hold position or cause the lever and thebendable region430 to return to a neutral deflection configuration (substantially straight). The spring nature of theouter tube406 and thebendable region430 can advantageously be used to cause a return to neutral once the deflection force is removed from the deflectinglever416. The stylet orobturator wire102 can be withdrawn or extended to expose or protect (respectively) the distal end of theintermediate tube404 which can be sharpened or blunted. Theobturator wire102 can further be used as the primary punch, especially if the distal tip of theobturator wire102 is sharpened. If theobturator wire102 is used as the primary punch, the proximal end of the intermediate tube hub is fitted with a Tuohy-Borst or other hemostatic valve to permit theobturator wire102 to remain in place. In this embodiment, sidearms affixed proximal to the proximal end of the punch, and operably connected to the central lumen, serve to permit pressure monitoring and dye contrast injection without compromising hemostasis or air entry into thepunch assembly400.
• FIG. 6 illustrates a side view of anadjustable spacer600 interconnecting aguide catheter620 and apunch assembly100. Thespacer600 further comprises aproximal connector602, arotating nut604, aninner telescoping tube608, a threadedregion606, adistal locking connector610, and anouter telescoping tube614. The guide catheter further comprises atube622, ahub624, and aproximal connector626. Thepunch assembly100 further comprises thestopcock110, the distalrotating locking connector612, theintermediate tube pointer112, theouter tube pointer114, and theintermediate tube hub116. Thespacer600 can comprise anoptional slot630.
• Referring toFIG. 6, thepunch assembly100 is inserted through the central lumen of theadjustable spacer600. The distal end of thepunch assembly100 is then inserted through the central lumen of theguide catheter620. Thehub624 of theguide catheter620 is affixed to the proximal end of theguide catheter tube622. The distal end of thehub624 comprises a female luer lock connection, which is bonded to, or integrally affixed to thehub624. Thehub624 can further comprise a seal or hemostasis valve such as a Tuohy-Borst fitting. Thepunch100hub116 is terminated at its distal end by a swivel maleluer lock connector612. Theadjustable spacer600 comprises anouter telescoping tube614, shown in partial cutaway view that is terminated at its proximal end with afemale luer lock602. The proximal end of theouter telescoping tube614 has a flange that permits rotational attachment of therotating nut604, shown in partial cutaway view, so that the rotating nut is constrained in position, longitudinally, relative to theouter telescoping tube614 but is free to rotate. Theinner telescoping tube608 is affixed at its distal end with a swivelmale luer connector610, or equivalent. The proximal end of theinner telescoping tube608 is affixed to, or comprises, the integral threadedregion606. The threadedregion606 mates with the internal threads on therotating nut604. As therotating nut604 is rotated, either manually or by an electromechanical device, it moves forward or backward on theinner telescoping tube608 and threadedregion606 thus changing the space between thehub116 of thepunch100 and the proximal end of thehub624 of theguide catheter620. The system is preferably set for spacing that pre-sets the amount of needle or stylet travel. In an embodiment, therotating nut604 comprises a quick release that allows disengagement of theinner telescoping tube608 from theouter telescoping tube614 so that collapse is permitted facilitating the tissue punching procedure of advancing thepunch100 distally relative to thehub624. The system further comprises hemostatic valves at some, or all, external connections to prevent air leaks into thepunch100. Thetelescoping tube608 can be set to disengage from theouter telescoping tube614 to allow for longitudinal collapse so that thepunch100 can be advanced distally to provide its tissue punching function. In another embodiment, thespacer600 comprises theslot630 that permits the spacer to be removed sideways off thepunch100. Theslot630 is wide enough to allow theouter tube106 to fit through theslot630 so thespacer600 can be pulled off, or removed from, thepunch100 prior to the punching operation. Thus, theslot630 can be about 0.048 to 0.060 inches wide and extend the full length of thespacer600. With theslot630, thespacer600 comprises a generally “C-shaped” lateral cross-section. Thespacer600 can further comprise a slot closure device (not shown) to prevent inadvertent removal of thepunch100.
• In another embodiment, the threadedregion606 and therotating nut604 are replaced by a friction lock on telescoping tubes, a ratchet lock, or other suitable distance locking mechanism. In yet another embodiment, a scale or series of markings (not shown) is incorporated into theadjustable spacer600 to display the exact distance between the proximal end and the distal end of thespacer600. In another embodiment, the proximal end and the distal end of thespacer600 do not comprise one or both of thefemale luer lock602 or the rotatingmale luer lock610. In this embodiment, thespacer600 provides positional spacing but does not affix thepunch100 to theguide catheter620 so that the two devices move longitudinally as a unit. In another embodiment, thepull wires412 ofFIG. 4, which are strong in tension but cannot support compression are replaced by one or more control rods, which are flexible but which have column strength. Thus, deflection can be generated by imparting either tension on the control rod or compression and such tension and compression is capable of deflecting the distal tip of thepunch400 without the need of a separate control rod to impart tension in the other direction. Theintermediate tube hub116 is terminated at its proximal end by a female luer, luer lock, threaded adapter, bayonet mount, or other quick release connector. The quick connect or female luer can be releasably affixed to a hemostasis valve, other stopcock, pressure transducer system, “Y” or “T” connector for pressure and radiopaque contrast media infusion, or the like.
• In another embodiment, a vacuum line can be connected to a port affixed to the proximal end of the punch. The port can be operably connected to a bell, cone, or other structure at he distal end of the punch by way of a lumen, such as the central lumen of the intermediate tube or an annulus between the intermediate and outer tube, within the punch. By application of a vacuum at the proximal end of the punch, the distal structure can be releasably secured to the atrial septum prior to punching through. In another embodiment, a corkscrew structure projects out the distal end of the punch and is operably connected to a knob or control at the proximal end of the punch by way of a control rod slideably or rotationally free to move within a lumen of the punch. The corkscrew structure can be screwed into tissue to releasably secure the distal end of the punch to the tissue, for example, to enhance stability of the punch prior to, during, or after the punching operation.
• Referring toFIG. 1, in another embodiment, theintermediate tube104, theouter tube106, or both, are fabricated from shape memory nitinol. In this embodiment, electrical energy can be applied to the pre-bent regions of theinner tube104, theouter tube106, or both. Upon application of electrical energy, Ohmic or resistive heating occurs causing temperature of the tubes to increase. The nitinol changes its state from martensitic to austenitic, with the increase in temperature, and can assume a pre-determined configuration or stress state, which is in this case curved. The austenite finish temperature for such a configuration is approximately 40 degrees centigrade or just above body temperature. In yet another embodiment, the austenitic finish temperature can be adjusted to be approximately 28 to 32 degrees centigrade. Thepunch100 can be maintained at room temperature where it is substantially martensitic and non-rigid. Upon exposure to body temperatures when it is inserted into the core lumen of the guide catheter, it will assume its austenitic shape since body temperature is around 37 degrees centigrade. This can cause thepunch100 to curve from substantially straight to substantially curved. In this configuration, only a single tube, either theintermediate tube104 or theouter tube106 is necessary, but both tubes, while potentially beneficial, are not required.
• The punch can be used to create holes in various structures in the body. It is primarily configured to serve as an articulating or variable deflection Brockenbrough needle. However, the steerable punch can be used for applications such as transluminal vessel anastomosis, biopsy retrieval, or creation of holes in hollow organs or lumen walls. The punch can be used in the cardiovascular system, the pulmonary system, the gastrointestinal system, or any other system comprising tubular lumens, where minimally invasive access is beneficial. The punch can be configured to be coring or non-coring in operation, depending on the shape of the distal end and whether an obturator or the circular hollow end of the punch is used to perform the punching operation. In the coring configuration, a plug of tissue is removed, while in the non-coring configuration, substantially no tissue is removed from the patient. The punch facilitates completion of transseptal procedures, simplifies routing of the catheters, minimizes the chance of embolic debris being dislodged into the patient, and improves the ability of the cardiologist to orient the punch for completion of the procedure. The punch of the present invention is integral and steerable. It is configured to be used with other catheters that may or may not be steerable, but the punch disclosed herein does not require external steerable catheters or catheters with steerability to be steerable as it is steerable or articulating on its own. The punch is capable of bending and unbending a practically unlimited number of times. The punch is especially useful with catheters that are not steerable since the punch comprises its own steering system.
• The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. For example, the deflectingwires412 can be replaced by an electromechanical actuator and external control unit. The scope of the invention is therefore indicated by the appended claims rather than the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims (19)

1. An apparatus adapted for punching a hole in a body lumen or hollow organ of a mammal comprising:

an outer axially elongate hollow tube having a proximal end and a distal end;

an inner axially elongate hollow tube having a proximal end and a distal end;

a central lumen within said outer tube and extending substantially the length of said tube, wherein the inner tube can concentrically reside and rotate about its longitudinal axis;

a central lumen within said inner tube and extending substantially the length of said tube;

a first hub affixed to the proximal end of the outer axially elongate tube;

a second hub affixed to the proximal end of the inner axially elongate tube;

lock to selectively fix the rotational position of the first hub relative to the second hub;

a distal end of the either the inner tube or the outer tube configured to be sharp, wherein the sharp distal end is capable of punching a hole in a structure within the body lumen or hollow organ; and

an obturator slidably disposed within the central lumen of the inner tube, wherein the obturator can be advanced forward out the distal end of the tube or it can be removed from the tube by withdrawal through the proximal end of the tube.

2. The apparatus ofclaim 1 wherein said second hub comprises a valve at its proximal end.

3. The apparatus ofclaim 1 wherein said inner tube and said outer tube form an assembly, further wherein the inner and outer tubes are each pre-bent to form a curve proximate their distal end, wherein alignment of the curves of the inner and outer tube causes the assembly to comprise a bend and wherein when the inner and outer tube bends are directed opposite each other, the punch is substantially straight and uncurved.

4. The apparatus ofclaim 1 comprising pull wires and a flexible region, wherein asymmetrical tension on the pull wires at the proximal end of the first hub causes the pull wires, which are affixed at a point distal to the flexible region to bend the inner and the outer tubes in the flexible region.

5. The apparatus ofclaim 1 wherein the first hub and the second hub comprise pointer devices to confirm alignment of the first hub relative to the second hub.

6. The apparatus ofclaim 1 comprising at least one control rod and a flexible region, wherein axial tension or compression on the control rod at the proximal end of the first hub causes the control rod, which is affixed at a point distal to the flexible region to bend the inner and the outer tubes in the flexible region.

7. The apparatus ofclaim 1 wherein axial advancement of the inner tube relative to the outer tube exposes a sharp distal end on the inner tube, wherein said sharp distal end is capable of punching a hole in tissue.

8. A method of punching a hole in a body lumen or hollow organ wall comprising the steps of:

Inserting a guidewire into a patient's body lumen and routing the guidewire to a location near a target site, wherein the target site is a organ or body lumen wall;

Advancing a guiding catheter over the guidewire to the target site;

Removing the guidewire;

Inserting an axially elongate punch into the guiding catheter and routing the punch to the target site, wherein the punch is substantially straight and uncurved;

Deflecting a region near the distal end of the punch so that the punch is oriented toward and against the target site; and

Punching a hole in the body lumen or hollow organ wall.

9. The method ofclaim 8 wherein the deflecting step comprises rotating a pre-curved intermediate tube relative to a pre-curved outer tube such that to maximize curvature, the curves of the intermediate tube and the outer tube are aligned with each other.

10. The method ofclaim 8 wherein the deflecting step comprises retracting or advancing a control rod, wherein the control rod extends substantially from the proximal end of the axially elongate punch to the region near the distal end of the punch that is deflected.

11. The method ofclaim 8 wherein the deflection step comprises electrically activating a shape memory actuator near the distal end of the punch.

12. The method ofclaim 8 wherein the deflection step comprises generating tension on one or more control wires, wherein the control wires extend substantially from the proximal end of the punch to the region near the distal end of the punch that is deflected.

14. The method ofclaim 8 further comprising the step of inserting an adjustable spacer between a hub of the punch and a hub of the guiding catheter, wherein the spacer prevents the distal tip of the punch to extend beyond the distal tip of the guiding catheter prior to the punching step.

15. The method ofclaim 8 further comprising the step of locking an adjustable spacer to a hub of the punch and a hub of the guiding catheter.

16. The method ofclaim 8 further comprising the step of advancing the punch through the hole in the body lumen or cavity.

17. The method ofclaim 8 further comprising the step of advancing the guide catheter and an obturator, having a central lumen, through the hole in the body lumen or cavity over the punch.

18. The method ofclaim 8 further comprising the step of removing the punch from the body lumen or cavity leaving a guide catheter in place.

19. An apparatus adapted for punching a hole in a body lumen or hollow organ wall comprising:

An axially elongate tube comprising a distal end, a proximal end and a central lumen;

A means for punching tissue disposed at or near the distal end of the axially elongate tube;

A means for protecting the sharp distal end of the axially elongate tube while said axially elongate tube is being advanced to the treatment site;

A means for deflecting a region near the distal end of the axially elongate tube from a straight to a substantially curved configuration; and

A means to actuate the punch from the proximal end of the axially elongate tube.

20. The apparatus ofclaim 19 wherein said means for protecting the sharp distal end of the axially elongate tube comprises an accessory catheter through which the punch is inserted.

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