Abstract: A catheter for delivering a medical electrical lead to a bundle of His from within a right atrium of a heart. The catheter includes a straight portion and a hook portion projecting from a distal end of the straight portion. The hook portion includes a first curved portion, a second curved portion, and a third curved portion. The straight portion and the first curved portion define a plane. The second curved portion extends from a distal end of the first curved portion. The second curved portion curves away from the plane. The third curved portion extends from a distal end of the second curved portion. The third curved portion curves toward the plane. The catheter forms a lumen extending from a proximal end of the straight portion to an opening at a distal end of the third curved portion.

Abstract: Catheter-based delivery systems for delivery and retrieval of a leadless pacemaker include features to facilitate improved manipulation of the catheter and improved capture and docking functionality of leadless pacemakers. Such functionality includes mechanisms directed to deflecting and locking a deflectable catheter, maintaining tension on a retrieval feature, protection from anti-rotation, and improved docking cap and drive gear assemblies.

Abstract: The present invention is directed to a multi-angulated catheter and methods of using the multi-angulated catheter. The multi-angulated catheter is so dimensioned as to facilitate accessing the left ventricle from an arm of a patient. The multi-angulated catheter generally includes in order: (a) a coiled end; (b) a first straight portion having a first straight portion length; (c) a first shaft including a distal end connected to the first straight portion and a proximal end opposite the distal end, the first shaft and the first straight portion defining a first obtuse angle, the first shaft having a first shaft length; and (d) a second shaft connected to the first shaft on said proximal end. The catheter is flexible so as to afford being straightened when it is advanced over a guide wire. The catheter resiliently returns to a multi-angulated position after the guide wire is withdrawn.

Abstract: Cardiac catheterization is carried out by clothing a subject in a torso vest having a plurality of sensing electrodes, magnetic location sensors, active current location sensors and patches for establishing galvanic contact with the skin. A multi-electrode probe is inserted into a cardiac chamber such that a plurality of intracardiac electrodes are disposed at respective locations in the heart. Respective locations are determined using the active current location sensors, Electrical calibration signals are emitted from the intracardiac electrodes, and received in the sensing electrodes of the torso vest. Relationships between the emitted calibration signals and the received calibration signals in the intracardiac electrodes are established to map a correspondence between the received calibration signals and the respective locations.

Abstract: Catheter-based delivery systems for delivery and retrieval of a leadless pacemaker include features to facilitate improved manipulation of the catheter and improved capture and docking functionality of leadless pacemakers. Such functionality includes mechanisms directed to deflecting and locking a deflectable catheter, maintaining tension on a retrieval feature, protection from anti-rotation, and improved docking cap and drive gear assemblies.

Abstract: A drainage catheter, comprising an elongate body member, an elongate flexible member and a hub, the hub including a base and a collar, the base an internal passageway and a side lumen and an outer surface including an engagement element and a mating surface portion, and the collar including a side lumen extending from the inner surface to the outer surface and wherein the inner surface of the collar includes a mating surface portion and a counter element, wherein the elongate flexible member extends through the side lumen side lumens, and wherein the hub has an unlocked position where the engagement element and the counter element are not engaged and a locked position where the engagement element and the counter element are engaged, the collar is tightened on the base and the elongate flexible element is clamped between the mating surface portions of the base and the collar.

Abstract: A high-frequency treatment instrument including: a sheath formed of a flexible material; an electrode member disposed inside the sheath; a distal-end member having a through-hole through which the electrode member passes; and a liquid supply means supplying liquid towards the front side via a flow path in the sheath, wherein the electrode member includes a rod-shaped electrode portion movably passing through the through-hole, and a large-diameter portion provided at the distal end thereof to have an outer diameter larger than the diameter of the through-hole, the large-diameter portion includes an electrode hole passing therethrough, between the distal-end member and the large-diameter portion, there is provided a buffer member that seals the periphery of a space between the distal-end member and the large-diameter portion.

Abstract: Guiding catheter comprising a first end and a second end, and at least three main portions being: a first linear portion connected to the first end, a second curved portion connected to the first linear portion, a third linear portion, connected to the second curved portion, opposite to the first linear portion, and connected to said second end, characterized in that said second curved portion subtends an angle ? from 195° to 240° and in that said third linear portion is provided to engage an active distal tip as fourth portion.

Abstract: This invention concerns a guide catheter comprising a hollow tubular body extending along a main longitudinal axis, said tubular body defining at ] least one internal lumen suitable for receiving at least one medical device, the tubular body further defining at least one proximal opening and one distal opening. The tubular body includes a distal portion preformed in such a way as to take on a curved configuration with regard to the main axis. At least the distal portion of the tubular body has a flattened shape that extends prevalently along a main transversal axis, the curvature of said distal portion being created around said main transversal axis.

Abstract: An applicator for mixing and applying multi-component compositions to a work surface, such as two-component surgical sealants. A luer hub sub-assembly having a proximal hub and a distal hub, an elongate, four-lumened cannula, and a spray tip sub-assembly are provided, with interconnections between the sub-assemblies preserving isolation of the fluid components from one another. The tip cap sub-assembly includes registration structure to assure proper alignment between tip cap and tip insert. The end wall of the tip cap includes a spinner region with three feeders or feeder channels leading thereto, the fluid components remaining isolated from one another in two of the feeders or feeder channels, and initiating mixing with one another in a third of the feeders or feeder channels.

Abstract: A catheter assembly for intracranial treatment of a subject that includes an outer tube that may be connected to an infusion or osmotic pump and delivered through a bendable catheter to the target brain site of the subject. The assembly facilitates regular accurate placement of drug or compound delivery at the tissue region without additional contact and minimizes trauma to the subject.

Abstract: Embodiments include an infusion-occlusion system having a delivery catheter, a guide catheter adapted to receive the delivery catheter, and a guidewire with an occlusion device adapted to be received within the guide catheter. The guide catheter of the catheter kit may be provided with an occlusion device at the distal end of the guide catheter. The delivery catheter may have an accessory lumen, coaxial or co-linear lumen, a supporting mandrel, or an occlusion device at its distal end. Moreover, according to some embodiments, occlusion devices may be a single material or a composite balloon having an inner liner and an outer layer of different materials, a high compliance low pressure balloon, or a filter device that restricts particles from passing through but does not restrict fluid, such as blood. An inflation device with a large volume and low volume syringe can be used to inflate the balloon.

Abstract: A catheter having improved ability to cross body passage obstructions and that more easily allows backloading of a guidewire into the lumen of the catheter is comprised of a tip, a shaft, and a lumen. The distal end of the catheter tip is oriented at an angle other than 90° to the lengthwise axis of the catheter tip. A guidewire may be easily backloaded into the elongated catheter lumen at the location of the angled catheter tip.

Abstract: A turbulator for promoting mixing of fluids passing through a body lumen includes an elongate flow perturbing component and an elongate shape controlling component freely slidable within the flow perturbing component. The turbulator is adjustable from a low profile, lumen access configuration to a deployed configuration via sliding the shape controlling component within the flow perturbing component. Adjusting the turbulator within a body lumen of a patient induces turbulence within a flow of fluid passing through the body lumen to increase mixing of a treatment fluid with the body fluid by way of the induced turbulence.

Abstract: A guide catheter assembly includes an outer guide catheter and an inner catheter slidably and rotatably disposed in the outer guide catheter. The outer guide catheter has a proximal portion and a distal portion formed into a preformed shape including a curved segment. The preformed shape includes a first arc, a second arc, a third arc, a fourth arc, and a generally straight terminal portion. The preformed shape is generally a J-shape defining, a generally open arc.

Abstract: Implants or systems of implants and methods apply a selected force vector or a selected combination of force vectors within or across the left atrium, which allow mitral valve leaflets to better coapt. The implants or systems of implants and methods make possible rapid deployment, facile endovascular delivery, and full intra-atrial retrievability. The implants or systems of implants and methods also make use of strong fluoroscopic landmarks. The implants or systems of implants and methods make use of an adjustable implant and a fixed length implant. The implants or systems of implants and methods may also utilize a bridge stop to secure the implant, and the methods of implantation employ various tools.

Abstract: Guiding catheter comprising a first end and a second end, and at least three main portions being: a first linear portion connected to the first end, a second curved portion connected to the first linear portion, a third linear portion, connected to the second curved portion, opposite to the first linear portion, and connected to said second end, characterized in that said second curved portion subtends an angle ? from 195° to 240° and in that said third linear portion is provided to engage an active distal tip as fourth portion.

Abstract: An endovascular sheath apparatus 2 is provided. The endovascular sheath apparatus 2 includes an inner tube 12 that includes a lumen 26 for introducing medical fluids or devices and an outer surface. The apparatus 2 further includes an outer tube 22 with an interior surface. The outer and inner surfaces define a cavity 28 therebetween. The apparatus 2 still further includes a stiffening component 20 which in one embodiment includes a braided material that is at least partially received in at least part of the cavity 28. An actuating mechanism 18 cooperates with the stiffening component 20. A method of providing intravascular delivery of a sheath includes the steps of providing an inner tube 12; positioning a stiffening component 20 around the inner tube 12; and deploying an actuating mechanism 18 that cooperates with the stiffening component 20, a stiffness characteristic of which being adjustable extra-corporeally by movement of the actuating mechanism in combination with the stiffening component.

Abstract: Complex steerable catheter visualization and tissue manipulation systems and their methods of use are disclosed herein. The deployment catheter is articulated using various steering mechanisms. Tissue visualization is accomplished from the visualization hood at the distal end of the deployment catheter, the hood having an ability to expand and other features to facilitate visualization and articulation at the tissue surface.

Abstract: A catheter that comprises a hub, an elongated conduit, and at least one lumen therein. The lumen includes a proximal lumen section, a distal lumen section, and an intermediate lumen section extending between the proximal and distal lumen sections. The cross-sectional dimension of the intermediate lumen section is less than the cross-sectional dimension of the distal lumen section. In one embodiment, the cross-sectional dimension of the intermediate lumen section is less than the cross-sectional dimension of the proximal lumen section. In certain embodiments, the lumen tapers from the distal and/or proximal lumen sections to the intermediate lumen section.

Abstract: A guide wire for medical treatment includes a straight-line shaped proximal section and a distal section which is continuous with the distal side of the proximal section and whose most distal portion faces toward the proximal direction. The distal section includes a curved portion continuous with the proximal section and a distal portion continuous with the distal side of the curved portion, the proximal section and at least a portion on the proximal side of the curved portion continuous with the proximal section are positioned on an identical plane, and the distal portion is extended toward a direction backing away from the plane and includes the most distal portion in a section of a direction to which the curved portion is curved with respect to an plane n an axis core of the proximal section orthogonal to the plane.

Abstract: A guide catheter assembly includes an outer guide catheter and an inner catheter slidably and rotatably disposed in the outer guide catheter. The outer guide catheter has a proximal portion and a distal portion formed into a preformed shape including a curved segment. The preformed shape includes a first arc, a second arc, a third arc, a fourth arc, and a generally straight terminal portion. The preformed shape is generally a J-shape, having a terminal portion generally parallel to the proximal portion, a generally closed arc or a generally open arc.

Abstract: A catheter for use in accessing a left atrium of a living heart within a subject's body by passing from the heart's right atrium to the heart's left atrium through a patent foramen ovale (PFO) in the heart, such as performing a percutaneous procedure for closing the PFO, includes a specialized preformed catheter with curves on the distal portion to be adapted within living anatomy to allow access from a subject's heart's right atrium through the PFO to the left atrium. The catheter facilitates access to the left atrium and the use of devices in procedures within and involving the left atrium, such as PFO closure devices. A method is also provided for using the catheter.

Abstract: A reinforced catheter having a non-filamentous, seamless metal tube interposed between a polymeric hollow core and a polymeric outer jacket. The metal tube may have a pattern of apertures through which the hollow core and the polymeric outer jacket are adhered to each other. The invention also includes methods of making the reinforced catheter.

Abstract: Some embodiments relate to a catheter system having a changeable or adjustable working length. The catheter system can comprise a proximal end, a distal end, and a first axial lumen configured to receive a guidewire formed through at least a portion of the catheter body. A first opening can be formed through a portion of the catheter body and be in communication with the first lumen. The sheath can be rotatable, axially movable, or otherwise changeable from at least a first position to a second position, wherein the sheath can substantially cover the first opening in the catheter body in the first position, and can substantially expose the first opening in the catheter body in the second position.

Abstract: The catheter device comprises a drive shaft connected to a motor, and a rotor mounted on the drive shaft at the distal end section. The rotor has a frame structure which is formed by a screw-like boundary frame and rotor struts extending radially inwards from the boundary frame. The rotor struts are fastened to the drive shaft by their ends opposite the boundary frame. Between the boundary frame and the drive shaft extends an elastic covering. The frame structure is made of an elastic material such that, after forced compression, the rotor unfolds automatically.

Abstract: A catheter has a control handle with at least an outer thumb control and an inner second thumb control. A longer puller wire has a distal end anchored at or near a distal end of distal deflectable portion. A shorter puller wire has a distal end anchored at or near a distal end of the proximal deflectable portion. For the shorter puller wire, a shorter compression coil has a distal end at or near a proximal end of the intermediate deflectable section. For the longer puller wire, a longer compression coil has a distal end at or near a distal end of the shorter puller wire. The inner and outer thumb controls include engagement members releasable by rotation of one thumb control relative to the other. When disengaged, the thumb controls each can be moved longitudinally relative to each other. When engaged, the thumb controls are coupled together for longitudinal movement as a single unit relative to the control handle.

Abstract: The disclosure provides a catheter for positioning in a contralateral femoral approach in highly angulated iliac bifurcations. The catheter comprises an elongate shaft, an adjustable element, and a wire entrance port on the elongate shaft. The elongate shaft has a proximal portion, an intermediate portion, a curved portion, and a distal portion. The curved portion connects the intermediate portion and the distal portion. The adjustable element is configured to encompass the distal portion and the intermediate portion together in a closed position. The adjustable element can be removed away from the distal portion permitting the distal portion in an open position. The wire entrance port is disposed in the intermediate portion near the curved portion. The distal portion is biased to be spaced away from the intermediate portion in the open position. The adjustable element is connected to an operating wire configured to advance and retreat through the wire entrance port.

Abstract: Devices and methods utilizing a catheter to remodel soft tissue of a patient and, in a preferred embodiment, to reduce the volume of the left ventricle of a heart. In some embodiments, one or more sutures are passed through a wall of the ventricle. The ends of the one suture and, more preferably, the multiples sutures are drawn together to draw tissue portions towards one another. In some embodiments, a tissue remodeling clip is implanted into a wall of the ventricle. Ends of the clip are resiliently biased to move relative to one another to draw tissue portions towards one another. In some embodiments, a tissue remodeling anchor includes a base and a plurality of legs attached to the base. The legs of the tissue anchor are implanted into a wall of the ventricle and moved toward one another to draw tissue portions toward one another.

Abstract: A method of cannulating the coronary sinus or accessing a side branch of the coronary sinus of a patient's heart using a guide catheter. The guide catheter has a proximal portion and a distal portion formed into a preformed shape configured such that the distal portion of the shaft is supported on a wall of the superior vena cava during insertion of the distal portion into the coronary sinus. The preformed shape includes a first arc, a second arc, a third arc, a fourth arc, and a generally straight terminal portion. The preformed shape is generally a J-shape, having a terminal portion generally parallel to the proximal portion, a generally closed arc or a generally open arc.

Abstract: A catheter for a coronary artery can include a distal end for being introduced into an opening of a coronary artery from an artery of an arm. The catheter can, include a catheter main body including a main body portion having a substantially linear shape in a natural state and a curved portion forming a portion extending from the main body portion to the distal end and having a curved shape in a natural state. The curved portion can include a first curve extending in a curved state from the main body portion, an intermediate portion extending from the first curve, a second curve extending from the intermediate portion and curved in a direction same as that of the first curve, and an extreme distal end portion of a substantially linear shape extending from the second curve. A method of using the catheter is also disclosed.

Abstract: A vessel tracking device for use with a pressure source has an elongate introduction element configured for introduction into a vessel of a human body, the introduction element having a proximal end and a distal end, and the distal end having a flexible distal end portion containing an internal cavity that is closed at the distal end. A pressure adjuster is configured for communication with said pressure source. The introduction element has a connection channel connected to the pressure adjuster at the proximal end of the introduction element, the connection channel being connected with the internal cavity and placing the internal cavity in communication with the pressure source, with the pressure adjuster controlling an internal pressure in the internal cavity. The distal end portion has different wall portions that are differently deformed as the internal pressure is adjusted, to produce a change in direction of the distal end controlled by the pressure controller.

Abstract: A catheter for insertion into the right atrium from the right subclavian vein has an elongate flexible shaft having a proximal portion and a distal portion. The distal portion has a preformed shape including a first arc portion having a curvature of from about 20 degrees to about 50 degrees relative to the proximal portion and a second arc portion extending distally from the first arc and having a curvature of from about 135 to about 200 degrees relative to the first portion. The first arc has an arc radius of from about 6 inches to about 10 inches and the second arc has an arc radius of from about 1 to about 2 inches. The catheter terminates in a generally straight terminal portion extending distally from the preformed shape.

Abstract: Described herein are devices and methods for guide catheters having one or more regions of increased flexibility. A flexibility region comprises one tubular segment of the guide catheter with a non-linear longitudinal seam between two non-concentric layers of material having different durometers. A non-linear seam, such as a zig-zag or sinusoidal configuration, permits controlled compression of lower durometer material between portions of higher durometer material.

Abstract: A catheter assembly including at least one introducer defining a passage receiving an elongate tubular member having a proximal end, a distal end, and a lumen extending between an elongate shape-imparting element received in the lumen and imparting a predetermined shape to the distal end of the elongate tubular member, when the distal end of the elongate tubular member is extended beyond a distal end of the at least one introducer. A distal end of the one-piece shape-imparting element extends from the lumen of the elongate tubular member and is anchored proximal the distal end of the at least one introducer.

Abstract: An introducer sheath is disclosed herein. The sheath includes a tubular body. The tubular body has a proximal zone, an intermediate zone and a distal zone. The proximal zone is generally straight. The intermediate zone extends from a distal end of the proximal zone and curves in a first direction. The distal zone extends from a distal end of the intermediate zone and curves in a second direction different from the first direction.

Abstract: An introducer system for implantation of pacemaker leads into the venous system of the human heart through the coronary sinus is comprised of a flexible, elongate, outer elongate element having a first shape or bias along a portion. The first shape on the outer element may be prebiased or may be initially straight and subsequently biased once deployed in the body chamber. A flexible, elongate, telescopic inner elongate element has a second shape or bias on its distal portion and has the first shape or bias on a more proximal portion. The inner elongate element is telescopically disposed in the outer sheath.

Abstract: A catheter pump includes a catheter channel communicating with a distal end portion of the catheter for alternatingly leading fluid in proximal and distal directions. At least one outlet passage is distally spaced from the inlet passage or passages. The catheter pump further includes a displacement structure communicating with the proximal end portion of the catheter for alternatingly applying suction and pressure for driving the fluid displacement. At least in operating condition, the inlet passage or passages are continuously open. A catheter and fittings for such a catheter pump and method of using a catheter pump are also described.

Abstract: A guide catheter for accessing the coronary sinus ostium has a proximal portion and a distal portion formed into a preformed shape including a curved segment. The preformed shape includes a first arc, a second arc, a third arc, a fourth arc, and a generally straight terminal portion. The preformed shape is generally a J-shape, having a terminal portion generally parallel to the proximal portion, a generally closed arc or a generally open arc.

Abstract: In a method and device for mounting an elongated member inside an elongated, elastic, flexible tubing, initially having an inside cross-sectional dimension that is approximately equal to or less than the outside cross-sectional dimension of the elongated member, the inner cross-sectional dimension of the flexible tubing is expanded by applying a pressurized fluid to the inner bore of the tubing, and inserting the elongated member into the tubing while the pressurized fluid is being applied.

Abstract: A catheter for a coronary artery can include a distal end for being introduced into an opening of a coronary artery from an artery of an arm. The catheter can, include a catheter main body including a main body portion having a substantially linear shape in a natural state and a curved portion forming a portion extending from the main body portion to the distal end and having a curved shape in a natural state. The curved portion can include a first curve extending in a curved state from the main body portion, an intermediate portion extending from the first curve, a second curve extending from the intermediate portion and curved in a direction same as that of the first curve, and an extreme distal end portion of a substantially linear shape extending from the second curve. A method of using the catheter is also disclosed.

Abstract: An improved apparatus and method to catheterize passages is disclosed. The present invention provides a catheter having a soft flexible pre-formed distal tip, that when used in combination with commercially available guidewires of variable stiffness, results in the ability to control the direction and angle of wire advancement allowing cannulation of body passages, including those that arise at acute angles. The catheter can have a longitudinal axis, a proximal section and a distal section having a soft flexible pre-formed tip having a curvature of ninety degrees or greater and shape retention. The catheter can have an inner wall that defines a lumen that runs along said longitudinal axis forming a single continuous tube, a reinforcement braid disposed over the inner wall, and an outside covering disposed over the reinforcement braid. A spacer can be added between said wall liner and said reinforcement braid in the proximal end.

Abstract: A steerable three dimensional catheter to engage the ostium of a right coronary artery in a patient includes: a torque-transmitting proximal shaft that receives manipulation by a user outside a patient in whom the catheter is used; and a distal shaft that is responsive to torque transmitted by the proximal shaft. The distal shaft includes a preformed support section having at least a segment that abuts a posterior or left lateral interior surface of the ascending aorta of the patient. The distal shaft also includes a preformed ostium entry section extending from the support section. In one implementation, the ostium entry section transitions from the support segment abutting the aortic wall to a distal tip end by way of at least two differently directed angles.

Abstract: A catheter having an elongate hollow shaft with a curved distal section having at least one pre-curved reinforcing strip embedded therein. The pre-curved reinforcing strip comprises a relatively stiff material that is unaffected by the process of thermoforming a final curve in the catheter. Methods of making the catheter are also described.

Abstract: A multiple catheter system is described. In one embodiment a medical catheter system includes a first catheter having an entrance orifice, an exit orifice, a channel connecting the entrance orifice and the exit orifice, and a wall surrounding the channel. In this embodiment the hardness of the wall surrounding the channel decreases in in hardness, increases in hardness and then decreases in hardness again, when considered from an initial reference point at the entrance orifice and traveling towards the exit orifice. Another medical catheter system includes a first catheter having an entrance orifice, an exit orifice, a channel linking the entrance orifice and the exit orifice, and a first wall surrounding the channel wherein the first wall has a bendable curve memory portion.

Abstract: A guide catheter for accessing the coronary sinus ostium has a proximal portion and a distal portion formed into a preformed shape including a curved segment. The preformed shape includes a first arc, a second arc, a third arc, a fourth arc, and a generally straight terminal portion. The preformed shape is generally a J-shape, having a terminal portion generally parallel to the proximal portion, a generally closed arc or a generally open arc.

Abstract: Provided is a catheter suitable for catheterization of a right coronary artery using a right transradial approach. The catheter presents improved directionality, thereby requiring minimized external torque to be applied during insertion and diagnostic procedures. A catheter according to the disclosed design includes a tip near its distal end, a primary curve, a secondary curve, a tertiary curve and a proximal end accessible external a catheterized body. When properly inserted, the secondary curve may rest near the junction of the bracheocephalic trunk and the right subclavian artery, and the tertiary curve may rest in the superior curve of the right subclavian artery. In addition to improved directionality, the secondary and/or tertiary curve offers additional resistance against cephalic, or upward, back-up force by providing caudal, or downward, torque to more distal portions of the catheter body.

Abstract: A catheter pump includes a catheter channel communicating with a distal end portion of the catheter for alternatingly leading fluid in proximal and distal directions. At least one outlet passage is distally spaced from the inlet passage or passages. The catheter pump further includes a displacement structure communicating with the proximal end portion of the catheter for alternatingly applying suction and pressure for driving the fluid displacement. At least in operating condition, the inlet passage or passages are continuously open. A catheter and fittings for such a catheter pump and method of using a catheter pump are also described.

Abstract: A catheter assembly comprises an outer catheter comprising a distal end curved portion having a first curved shape, and an inner catheter which comprises a distal end curved portion having a second curved shape different from the first curved shape and which can be inserted into the outer catheter so that the distal end curved portion thereof is located in the distal end curved portion of the outer catheter and be withdrawn therefrom. The distal end curved portion of the outer catheter is more flexible than the distal end curved portion of the inner catheter. A distal end portion of the catheter assembly, when the inner catheter is inserted in the outer catheter so that the distal end curved portion of the inner catheter is located in the distal end curved portion of the outer catheter, assumes a curved shape different from the first curved shape.

Abstract: The invention is defined as a precurved coronary sinus guiding introducer for use in a cardiomyopathic heart comprising a flexible elongated member with a proximal and distal end. The elongated member comprises a generally straight, proximal portion and a precurved distal portion. In one embodiment the proximal portion and distal portion are formed to lie is a common plane. In another embodiment the portions are angulated with respect to each other in different planes. The precurved distal portion comprises at least one curved subportion and at least one curved or straight subportion. The precurved distal subportion curves through a generally circular arc away and is defined by a chord of predetermined length. The precurved distal subportion has a predetermined height above the chord. The curved or straight subportion is the distal section of the precurved distal portion.