WO2008036842A2

WO2008036842A2 - Device and method for facilitating introduction of catheters

Info

Publication number: WO2008036842A2
Application number: PCT/US2007/079075
Authority: WO
Inventors: David R. Miller; Michael Smith
Original assignee: Kyphon Sarl
Priority date: 2006-09-21
Filing date: 2007-09-20
Publication date: 2008-03-27
Also published as: EP2068996A2; WO2008036842A3; EP2068996A4

Abstract

A guide structure for facilitating the introduction of a guidewire into a catheter comprises a body having a guide channel therethrough. An attachment end of the guide structure is adapted to receive and align a distal end of the catheter within the guide channel, A receiving end of the guide structure is adapted to receive and align a guidewire with a guidewire iumen within the catheter, when the catheter is held within fhe guide structure.

Description

DEVICEAND METHOD FOR FACILITATING INTRODUCTION OF CATHETERS

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of and claims priority from US Patent Application No. 11/764,029 as filed on June 15, 2007; US Patent Application No. 11/771,768 as filed on June 29, 2007; and claims the benefit under 35 USC 119(e) of US Provisional Application No. 60/826,472 as filed on September 21, 2006, the full disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention. The present invention is related generally to medical apparatus and methods. In particular, the invention is directed at structures and methods for introducing medical catheters into tissue.

[0003] A wide variety of medical procedures require placing a catheter or other medical device over a guidewire. Many of these procedures are performed in the vasculature, including angioplasty, atherectomy, stent delivery, and the like. Many other procedures are performed in non-vascular lumens, including urinary procedures in the urethra and ureter, and the like. Of particular interest to the present invention are those procedures performed with very small diameter catheters which must be introduced over very small guidewires, such as the Functional Anesthetic Discography (FAD), a procedure in the spinal disc space, which utilizes a guidewire, which utilizes a guidewire typically having a diameter of about 0.009 inches, and a diameter of a guidewire lumen in a catheter of about 0.011 inches. The guidewires are placed under sterile conditions in the operative environment where introduction of guidewires into the catheter can be difficult, particularly when very small catheters and guidewires are involved.

[0004] For these reasons, it would be desirable to provide apparatus and methods for facilitating the introduction of an end of a guidewire into the port of a guidewire lumen in a medical catheter. It would be particularly desirable if such methods and apparatus assured the proper alignment of the guidewire with minimum effort, even under conditions of low light and limited visibility, as often is the case in radiology laboratories where many of these procedures are performed. [0005] 2. Description of Background Art. U.S. Patent Publication No. 2005/0234425 describes a FAD catheter which may be introduced over a guidewire and which can benefit from the facilitated guidewire introduction apparatus and methods of the present invention.

BRIEF SUMMARY OF THE INVENTION

[0006] The present invention provides apparatus and methods for facilitating the introduction of a medical catheter. For example, embodiments may be particularly useful for placement of very small guidewires, which may have, for example, diameters of about 0.009 inches or below, into very small guidewire lumens, which may have, for example, diameters of about 0.011 inches or below.

[0007] In one aspect, the apparatus of the present invention comprises guidewire structures for loading a guidewire into the lumen of a catheter. The guidewire structures comprise a body (also referred to as "guide-body") having a receiving end, an attachment end, and a guide channel therebetween. The attachment end removably attaches to an end of the guidewire such that the guidewire lumen of a catheter is aligned with the guide channel. The receiving end of the guide structure body receives an end of the guidewire such that the guidewire can be advanced through the guide channel and into the lumen of the catheter. Typically, the guide structure may further comprise a handle on the body to facilitate manipulation during the guidewire introduction. The guidewire may be conveniently located to project laterally from a location at or near the attachment end of the body, although it could also be at other locations.

[0008] In the specific embodiments, the attachment end of the body of the guide structure is flared to provide an enlarged target area for capturing the catheter and guiding the catheter into the guide channel. Thus, in one aspect, a catheter may be inserted into the guide structure at the attachment end of the guide body and through the guide channel. In another aspect, a portion of the guide channel may be shaped to conform to the shape of an outer distal end of the catheter to, for example, form a tapered section or, a "stop" or "limiting stop" that engages and aligns the lumen of the catheter with the guide channel.. Thus, when the catheter is introduced into the attachment end of the guide body, the catheter will fit snugly so that it is aligned within the guide channel and can be inserted to a preselected depth as determined by the limiting stop.

[0009] In other exemplary aspects of the guide structure, the receiving end of the guide body may also be flared to provide an enlarged target area for receiving the guidewire. Often, the flare is generally conical in shape and coaxially positioned around an axis of the guide channel. A transition region may be provided in the guide channel for aligning the guidewire as it is advanced through the guide channel at the open end or port of the guidewire lumen in the catheter. Thus, after placing the catheter into the attachment end of the guide structure, the physician may easily advance the guidewire through the receiving end and into the guidewire lumen of the catheter.

[0010] In another specific aspect of the present invention, the guide body may be adapted to laterally release the catheter and guidewire from the guide structure or remove the guide structure from the catheter and guidewire assembly. For example, the guide body may be axially slit or splittable along a wall of the guide channel. A slit would permit the catheter and guidewire to be pulled from the channel while leaving the guide body intact. Splittable guide bodies will allow the user to pull the guide body apart and remove the guide structure from the catheter and guidewire. In other embodiments, the guide body may be open along one side of the guide channel so that the catheter and guidewire may be pulled from the channel with minimum effort. With such open channel configurations, detents, protrusions, or other simple components may be provided to hold the catheter in place as the guidewire is advanced.

[0011] Methods according to the present invention for inserting a guidewire into the lumen of a catheter comprise removably attaching a guide structure onto an end of the catheter. The guide structure includes a channel which aligns with a guidewire port on the lumen when the catheter is in place in the channel. After the catheter has been placed in the guide structure, an end of the guidewire is introduced through the channel of the guidewire structure and into the lumen of the catheter. After the guidewire is in place in the catheter, the guide structure may be removed from the catheter.

[0012] Removably attaching the guide structure to the catheter may comprise inserting an end of the catheter through a flared attachment end of the guide structure channel. Typically, when introduced through the flared attachment end of the guide structure, the catheter will be captured in a shaped portion of the channel where it engages a stop for final positioning.

[0013] Introducing an end of the catheter typically comprises inserting the guidewire end through a flared receiving end of the guide structure channel after the guide structure has been attached to the catheter. Typically, the flared receiving end has a generally conical shape.

[0014] Removing the guide structure from the catheter may comprise pulling the catheter and guidewire laterally from the guide structure. In such cases, the guidewire and catheter may be pulled through an axial slit which is preformed in the guide structure. Alternatively, the guidewire and catheter may be pulled through a pre-formed discrete opening in the channel. Alternatively, the guide structure may be removed from the catheter and guidewire by splitting the guide structure, typically by pulling the guide structure apart at one end so that the structure separates into two pieces which may then be pulled away from the catheter and guidewire. Alternatively the guide structure could be radially expanded facilitating removal from the catheter by passing it over the proximal end of the catheter.

[0015] In yet another variation, the guide structure is utilized for placement of a catheter over the proximal portion of an elongated and flexible guidewire having its distal end inserted within a patient's body. In one example, a physician first inserts the distal portion of a flexible and elongated guidewire into a patient's body through one of various methods that are well known to one of ordinary skill in the art. The physician then places a guide structure over the distal portion of a catheter. The distal widened-end (e.g., funnel-shaped opening) of the guide structure is then placed over the proximal end of the flexible guidewire. With the guide structure directing the distal tip of guidewire, the catheter is advanced over the proximal portion of the guidewire. Once the catheter is placed over a portion of the guidewire, the physician may then remove the guide structure. The physician can further propell the catheter along the length of the guidewire until the distal portion of the catheter enters the patients body.

[0016] In one application, the guide structure is preloaded on the catheter, and provided to the physician in a sterile package, such that the physician may place the catheter onto the guidewire right out of the package without the need to further position and/or orient the guide structure. In addition, the catheter may have a penetrating tip (e.g., a stiffened and/or tapered tip portion) and/or an anchoring mechanism (e.g., an expandable balloon) at the distal tip portion. The guide structure may be configured to be preloaded on the distal portion of the catheter to provide protection for the penetrating tip and/or the anchoring mechanism. In one variation, the inner lumen of the guide structure is configured with a profile for receiving the penetrating tip and/or the anchoring mechanism.

[0017] In another aspect, embodiments of the present invention provide an apparatus. The apparatus comprises a guide structure, and a catheter.

[0018] In many embodiments, the apparatus comprises a sterile package with the guide structure pre-loaded on the catheter within a sterile package. The catheter may be on the catheter within the sterile package such that a user may place the catheter onto a guidewire. The catheter can be positioned within a guide channel of the guide structure, and the guide structure can be removably attached to the catheter. In some embodiments, the catheter comprises a balloon and a penetrating tip. The guide structure can be configured to protect the penetrating tip of the catheter and the balloon of the catheter.

[0019] In many embodiments, the apparatus comprises a guidewire. The guidewire may comprise a diameter of about 0.009 inches or below. The catheter may comprise a lumen with a diameter of about 0.011 inches or below.

[0020] In many embodiments, the guide structure comprises a guide body having a receiving end, an attachment end, and a guide channel extending therebetween. The receiving end may comprise a diameter of about 0.25inches. In some embodiments, the receiving end comprises a diameter in a range from about 0.20 to about 0.27 inches. The guide channel may comprise a diameter within a range from about 0.035 to about 0.038 inches. The guide channel diameter may be sized from about 0.0001 inches to about 0.010 inches smaller than a diameter of the catheter so as to form an interference fit. The guide channel comprises a guidewire section with a diameter within a range from about 0.010 inches to about 0.014 inches.

[0021] In specific embodiments, the attachment end may comprises a diameter from about 0.035 inches to about 0.05 inches.

[0022] It is also contemplated that the guide structure and method of use thereof, may be implemented in combination with the devices and methods described in U.S. Patent Publication No. 2005/0234425, which is incorporated herein by reference in its entirety for all purposes. In one example, the method comprises placing the distal portion of an elongated (e.g., 12 inches or longer) and flexible guidewire percutaneously into a spinal disc in a patient's body. The distal widened end of a guide structure, which is attached to the distal portion of a catheter, is placed over the distal tip of the guidewire. As the physician advance the catheter forward in relation to the guidewire, a transition region within the guide structure aligns the guidewire with the lumen of the catheter. Once the distal portion of the catheter is inserted over the proximal portion of the guidewire, the physician may then remove the guide structure through various methods described herein. For example, the catheter can be advanced distally such that the guide structure contacts an introducer device, for example an introducer needle, and the guide structure is released from the end of the catheter. The distal portion of the catheter is further advanced over the guidewire and into the patients body, followed by penetration into the spinal disc. Once the distal portion of the catheter has entered the disc, an optional anchoring mechanism on the catheter may be deployed to secure the distal portion of the catheter within the disc. [0023] Embodiments of the present invention provide flexibility with many of the usage situations described above, can facilitate evaluation of spinal discs, and in at least some instances may permit less invasive FAD and other forms of discography. In many embodiments, system, typically in the form of a kit, is provided which allows the user to select how to perform the disc diagnosis with the components of the system. The system components may include a FAD catheter, a guidewire and stylet, in which both the guidewire and stylet are compatible with the catheter. The user may select to insert the catheter into the disc with a stylet included in the system. As the catheter has a lumen sized to receive either the stylet or the guidewire, the user may select to insert the catheter into the disc with a guidewire included in the system, for example after the guidewire has been placed with a rigid needle. Some embodiments of the present invention can utilize needles that have already been placed to introduce the FAD catheter quickly and safely, so as to avoid additional needle penetration and associated pain. For example, a clinician may access the disc with a standard needle and use this needle to place the catheter, even if a standard discography is not performed.

[0024] In an aspect, embodiments of the present invention provide a system for accessing an interior of an intervertebral disc. The system comprises an intervertebral disc access catheter having at least one lumen for introducing one or more substances into the interior of the intervertebral disc. The system also comprises a stylet that is removably receivable in the at least one lumen. The stylet has a tissue-penetrating distal tip, which extends from a distal end of the catheter when the stylet is in place in the lumen. The tip will usually comprise an integrated sharpened end, but could alternatively comprise a radiofrequency electrode (capable of applying cutting current), a removably or separately formed sharpened end, or the like. A removable guidewire that is receivable in the at least one lumen is also included in the system A user can select to advance percutaneously the access catheter to the disc interior using the stylet, or the user can select to remove the stylet and introduce the access catheter over a guidewire to the disc interior.

[0025] In many embodiments, the intervertebral disc access catheter comprises an elongate flexible catheter body. The catheter body may have a proximal portion and a distal portion. The disc access catheter may comprise an inflatable anchoring balloon on the distal portion of the catheter body and an injection tube or lumen in the elongate body. The injection tube or lumen may be adapted to removably receive either the guidewire or the stylet. In specific embodiments, the intervertebral disc catheter may comprise an inflation tube or lumen in the elongate body. [0026] In many embodiments, the intervertebral disc access catheter has an outer diameter in the range from 0.4 mm to 1.5 mm, and an injection lumen diameter in the range from 0.08 mm to 0.8 mm. The disc access catheter may have an inflation lumen diameter in the range from 0.08 mm to 0.8 mm, and a length in the range from 10 cm to 62 cm. The guidewire may have a diameter in the range from 0.02 mm to 0.8 mm, and the stylet may have a diameter in the range from 0.02 mm to 0.8 mm and a length in the range from 20 cm to 80 cm. The guidewire may has a length in a range from about 20 cm to about 80 cm.

[0027] In another aspect, embodiments of the present invention provide a method for accessing the interior of an intervertebral disc. The method may comprise providing a system as described above, and the access catheter may be advanced to the disc interior using the stylet.

[0028] In many embodiments, a method for accessing the interior of an intervertebral disc is provided. The method may comprise providing a system as described above. A needle may be percutaneously advanced into the interior of the intervertebral disc, and the catheter may be advanced over the guidewire so that a distal end of the catheter is positioned in the disc.

[0029] In many embodiments, a method for assessing the condition of an intervertebral disc may be provided. The method may comprise percutaneously advancing a needle into an intervertebral disc. The condition ofthe disc may be assessed using X-ray. If further assessment is desired, a guidewire may be advanced through the needle in response to the condition assessed with X-ray, and the needle may be removed over the guidewire in response to the condition assessed with X-ray. A catheter may be advanced over the guidewire in response to the condition assessed with X-ray, so that a distal end ofthe catheter is positioned in the disc. At least one anesthetic or analgesic may be introduced through the catheter. The condition ofthe disc may be further assessed based on the patient's response to the anesthetic or analgesic.

[0030] In many embodiments, a method for assessing the condition of an intervertebral disc having an annulus and a nucleus is provided. A system is provided which comprises a needle, a catheter, a stylet and a guidewire. The stylet is provided inside a lumen ofthe catheter. Either the guidewire or the stylet is selected to position a distal end ofthe catheter through the annulus into the nucleus. The distal end ofthe catheter is advanced into the nucleus with either the guidewire or the stylet in response to the selection.

[0031] In specific embodiments, the needle can be selected in response to a location ofthe disc in the patient, and the needle can be selected in response to a previously placed catheter. [0032] In some embodiments, the system is comprised within a sterile package comprising a kit, and a plurality of sterile kits are provided to the physician for assessing a plurality of discs, hi specific embodiments, each kit of the plurality of kits corresponds to an evaluated disc of the plurality of discs.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Fig. 1 illustrates one embodiment of the guide structure constructed in accordance with the principles of the present invention.

[0034] Figs. 2A-2D illustrate the steps in introducing a guidewire into a catheter using the exemplary guide structure of Fig. 1.

[0035] Fig. 3 illustrates the guide structure used with an FAD catheter comprising an anchor, according to embodiments of the present invention.

[0036] Fig. 4 illustrates dimensions of the guide structure, according to embodiments of the present invention.

[0037] Fig. 5 A shows a kit, according to embodiments of the present invention;

[0038] Figs. 5B and SC show components of the kit as in Fig. 5 A in detail, according to embodiments of the present invention;

[0039] Figs. 6A-6D show a method of accessing the interior of an intervertebral disc with components of a kit as in Fig. 5 A, in which an access catheter can be advanced into the interior of the disc with a stylet, according to embodiments of the present invention; and

[0040] Figs. 7A-7K show a method of accessing the interior of an intervertebral disc with components of a kit as in Fig. 5 A, in which a needle can be percutaneously advanced to the interior of the disc and a catheter can be advanced over a guidewire positioned with the needle, according to embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0041] The present invention provides apparatus and methods for facilitating the introduction of a guidewire into a guidewire lumen in a medical catheter. Embodiments of the invention may be particularly useful for placement of very small guidewires, which may have, for example , diameters of about 0.009 inches or below, into very small guidewire lumens, which may have, for example, diameters of about 0.011 inches or below. The apparatus may comprise guidewire structures for loading a guidewire into the lumen of a catheter. The guidewire structures comprise a body having a receiving end, an attachment end, and a guide channel therebetween. The attachment end removably attaches to an end of the guidewire such that the guidewire lumen of a catheter is aligned with the guide channel. The receiving end of the guide structure body receives an end of the guidewire such that the guidewire can be advanced through the guide channel and into the lumen of the catheter. Typically, the guide structure may further comprise a handle on the body to facilitate manipulation during the guidewire introduction. The guidewire may be conveniently located to project laterally from a location at or near the attachment end of the body, although it could also be at other locations.

[0042] The flared receiving end of the guide structure channel typically has an opening or "target area" that is substantially larger than the lumen in the catheter, often having a diameter of about 5 to about 1000 times larger than the guidewire diameter. In one variation, the opening flare or funnel is configured with a diameter of about 0.25 inches and tapers down to an area about the size of the lumen in the catheter that accepts the guidewire. The tapered down diameter of the flare is the same size or slightly larger than the guidewire and preferably the same size or slightly smaller than the lumen in the catheter that accepts the guidewire. The included angle of the interior guidewire flare or funnel could be between about 5 and about 120

[0043] In some aspects, the catheter may be back-loaded over a guidewire that is already in place in the patient, and the guide structure may be trapped at the distal end of the catheter after the catheter has been place over the guidewire. Thus, the guide structure may be adapted to be removed from the guidewire and catheter assembly. For example, the guide structure may be (a) adapted for splitting or peeling the guide structure longitudinally into two or more parts or (b) have an axial slit or opening such that the guidewire and catheter assembly can be pulled through the slit or opening. Such slit in the channel may be, for example, a substantially straight slit, a spiral cut, or a combination of a straight slit or spiral cut. The slit, for example, could also be complete or intermittent (also referred to as perforated). Such a perforated slit would allow the guide structure to function like an intact tube, but still allow removal of the guide structure from the catheter and guidewire assembly by splitting the slit.

[0044] In another aspect, the guide structure may have one or more pull tabs that assist in its removal from the catheter and guidewire assembly, particularly by splitting. Such pull tabs may be located on the guide structure and may be sized such that the pull tabs may be easily grasped. [0045] Other optional features of the guide structure include an interior tapered section or "stop" that engages and aligns the lumen of the catheter with the channel. This tapered section allows for proper alignment between the guide structure and the catheter for catheters with lumens that are not in the middle of the device and for variations in size and construction of the catheter or guide structure. The included angle of the interior tapered section could be between about 5 and about 120 degrees. In a preferred aspect, the angle of the interior tapered section could be about 60 degrees.

[0046] In another embodiment, the guide structure may be secured to the catheter by an interference fit (also known as press fit or friction fit) such that after the guidewire is introduced into the lumen of the catheter the guide structure and catheter are securely held together by the friction between two components, yet the guide structure and catheter may be are easily separable by use of moderate force. The interference fit may be formed by sizing the guide channel to have an inside diameter of about 0.0001" to 0.010" smaller than the outside diameter of the catheter. An interference fit may also be formed by small ribs in the channel or may be formed by different shapes for the channel and catheter (for example one straight, one curved, or one straight, one corkscrew shaped).

[0047] In another embodiment, the catheter may have a balloon near its distal tip. The balloons may require having a sleeve or cover over them during storage and shipment which may, for example, protect the balloon from damage and/or keep the balloon pleats compressed in order to minimize the passing profile of the balloon. In a particular embodiment, the guide structure is integrated into a balloon cover. Examples of balloons useful in embodiments of the present invention are described in U.S. Pub. No. 2005/0234425, the full disclosure of which has been previously incorporated herein by reference.

[0048] Various materials may be used to make the guide structure as required of a specific application. The guide structure, for example, may be made out of a soft material such as a polymer extrusion. Polymer extrusion materials that may be used include, but are not limited to nylon 11, nylon 12, high-densily polyethylene, low-densily polyethylene, PEEK, urethane, and polyurethane. The guide structure could also be injection molded. In a preferred embodiment the guide structure is formed out of extruded high-density polyethylene.

[0049] In another embodiment, the material used to make the guide structure may comprise or contain a material that is radiopaque. A radiopaque material may allow the physician to visualize the guide structure using fluoroscopy. [0050] In a further embodiment, the material of the guide structure could consist of or contain a material that may glow or luminate in the dark or under light or visibility. This would allow the physician to more easily place, locate, and manipulate the structure in a dark room or room which is under low light or limited visibility.

[0051] In yet a further embodiment, the material used to make the guide structure may comprise or contain, or be coated with a material that is highly lubricious. Such a material would allow for (a) easier assembly of the guide structure onto the catheter, (b) easier removal of the guide structure from the catheter, or (c) easier passage of the guidewire through the guide structure and into the catheter. Such material may be, for example, a hydrophilic or hydrophobic coating, a dry lubricant like parylene, or a material from the Teflon family such as PTFE, ePTFE, or FEP.

[0052] A guide structure may be manufactured in a variety of different ways. For example, the guide structure may be formed from an extruded tube, by using methods such as heating and using specialized tooling to create the desired interior and exterior features, or the guide structure may be injection molded or machined into its final form. A slit in the guide structure or in a portion of the guide structure may be created using a variety of techniques known in the art such as using a laser, using a heated element, or using a cutting tool. The resulting slit may be about 0.0001" to about 0.050" in width. Alternatively the guide structure may be biased to close after the slit is formed which may result in a slit width of zero width unless the slit is forcibly opened. Alternatively the slit may have a width that varies over its length.

[0053] Referring now to Fig. 1 , an exemplary embodiment of a guide structure constructed in accordance with the principles of the present invention will be described. The guide structure 10 comprises a body 12 having a receiving end 14 and an attachment end 16. A guide channel 18 (best seen in Fig. 2A) extends between the receiving end 14 and attachment end 16. A handle 20 may be provided, typically projecting laterally from near the attachment end of the guide structure. In the illustrated embodiment, an axial slit 22 extends the entire length of the guide structure 10 so that the assembly of the catheter and guidewire may be pulled from the guide structure after the loading procedure is completed.

[0054] The receiving end 14 of the guide structure is typically formed as a conical extension or funnel 24 having an open end or target area 26 through which the physician inserts a guidewire into the catheter. Similarly, the attachment end 16 of the guide structure may be flared, for example having a pair of diverging sections 28 which help channel the catheter into the channel. Generally, as the catheter body is larger and easier to manipulate than the guidewire, the amount of flaring on the attachment end 16 of the guide structure 10 need not be as great or as large as the diameter of the receiving end 14.

[0055] Referring now to Figs. 2A-2D, a catheter C (Fig. 2B) is introduced through the flared section 28 of the guide structure 10 and is received in a section 30 of channel 18 which is configured to conform closely to the distal end of the catheter. A stop section 32 is formed in the channel, where the stop is typically tapered to conform to the distal end DE of the catheter, as shown in Fig. 2B. The dimensions and alignments of the conforming section 30 and stop 32 are selected so that a distal guidewire port (not shown) in catheter C will be aligned with guidewire section 34 of the channel 18.

[0056] Thus, once the catheter C is in place in the guide channel 18, as shown in Fig. 2B, the guidewire GW is inserted through the target area 26 of the conical structure 24 in the direction of arrow 40, as shown in Fig. 2C. As the end of the guidewire GW is advanced, it is directed into the guidewire section 34 of channel 18, as shown in Fig. 2D. Once in the distal end of the guidewire lumen in catheter C, the guidewire GW may be further or fully advanced into the catheter. After such advancement, it will usually be necessary to remove the guide structure 10 from the assembly of the catheter C and guidewire GW. In the illustrated embodiment, this can be achieved by pulling the catheter and guidewire through the axial slit 22 in the direction of the arrows shown in Fig. 2D. Alternatively, as discussed elsewhere, the guide structure could be axially split, or the slit could be spiral or have other configurations. Alternatively, the guide structure could be removed by passing the guide structure proximally off of the catheter by pulling tab 20 or pushing in a proximal direction on the target area 26 or any portion of the guide catheter. Once the guide structure 10 has been removed, the catheter may be advanced into the patient over the guidewire in a conventional manner.

[0057] Fig. 3 illustrates the guide structure used with an FAD catheter 300 comprising an anchoring mechanism 310, according to embodiments of the present invention. The guide structure as described above is shown with an FAD catheter, as describe in U.S. Patent Publication No. 200S/023442S, the full disclosure of which has been previously incorporated herein by reference. Catheter 300 may comprise a penetrating tip 320. The guide structure can preloaded on the catheter, and provided to the physician in a sterile package, such that the physician may place the catheter onto the guidewire right out of the package without the need to further position and/or orient the guide structure. In addition, penetrating tip 320 may comprise, a stiffened and/or tapered tip portion. Anchoring mechanism 310 may comprise an expandable balloon at the distal tip portion. The guide structure may be configured to be preloaded on the distal portion of the catheter to provide protection for the penetrating tip and/or the anchoring mechanism. In some embodiments, the inner lumen of the guide structure is configured with a profile for receiving the penetrating tip and/or the anchoring mechanism

[0058] In some embodiments, guide structure may be removed by advancing the catheter distally such that the guide structure contacts an introducer device 330, or introducer needle, as described in U.S. Patent Publication No. 2005/0234425, previously incorporated herein by reference. Contact between the guide structure and introducer device 330 can split open the slit in the guide structure so as to release the guide structure from the distal end of the catheter, for example by falling off the distal end of the catheter.

[0059] Fig. 4 illustrates dimensions of the guide structure 400, according to embodiments of the present invention. The guide structure comprises a guide body 402 having a receiving end 404, an attachment end 406, and a guide channel 408 extending therebetween. The receiving end comprises a diameter 440 within a range from about 0.20 to about 0.27 inches, for example about 0.25 inches. The guide channel comprises a diameter 410 within a range from about 0.035 to about 0.038 inches. The guide channel diameter is sized from about 0.0001 inches to about 0.010 inches smaller than a diameter of FAD catheter 300so as to form an interference fit The guide channel comprises a guidewire section 409 with a diameter 430 within a range from about 0.010 inches to about 0.014 inches. Attachment end 406 comprises a diameter 420 within a range from about 0.035 inches to about 0.05 inches. Receiving end 404 extends for the body at an angle 460 within a range from about 55 to 65 degrees, for example about 60 degrees. A length 420 of a stop section 432 comprises a length of about 0.04 inches. Guidewire section 409 comprises a length 480 of about 0.14 inches. Receiving end 404 comprises a thickness 450 of about 0.12 inches. A thickness of Ihe body wall is about 0.01 inches. An overall length 491 of guide structure 400 may be within a range from about 0.9 to about 1.1 inches, for example about 1 inch.

[0060] Embodiments of the present invention can be used in many flexible ways to benefit clinical procedures, including Functional Anesthetic Discography (FAD) and traditional provocative discography (PD). For example, a clinician may use kit components to place a FAD catheter at all disc levels being tested and perform a provocative discography with each placed FAD catheter. Alternatively or in combination, the clinician may use the kit components to perform a traditional provocative discography and place a FAD catheter at the level of the disc in response to the disc testing is positive. The FAD catheter anchor may be deployed and the functional portion of the FAD testing conducted in response to the positive test result of the disc. In some embodiments, the clinician may place a FAD catheter from the kit without performing the provocative discography, for example in response to physical exams, imaging studies such as x-ray or MRI, or previous discographies that have been performed.

[0061] Referring now to Fig. SA, a schematic illustration of a system, or kit 500, is shown, according to embodiments of the present invention. Kit 500 comprises a catheter 510, a stylet 530 and a guidewire 540. Catheter 510 may comprise an elongate and flexible catheter body 511. Catheter body 511 comprises a proximal portion 512 and a distal portion 514. An adapter 518A and an adapted 518B may be connected to catheter 510 near proximal portion 512. Catheter 510 comprises a length 528. Length 528 may comprise many suitable lengths, and length 528 may comprise a range of lengths from about 10 to 62 cm Stylet 530 passes though an opening 515 formed near the distal end of catheter 510. Catheter 510 may comprise many suitable materials, for example braid reinforced polyimide tubing, and many materials as described in U.S. App. No. 10/825,961, the full disclosure of which has been previously incorporated by reference.

[0062] An anchor 516 is located near distal portion 514 of the catheter body. Anchor 516 may comprise an expandable member, such as an expandable balloon, to anchor the catheter in the disc. Anchor 516 may comprise many suitable structures that anchor the catheter in and/or near the disc. In many embodiments, anchor 516 may comprise an expandable balloon that can be inflated upon injection of a fluid through inflation tube 525. Many suitable anchor structures are described in U.S. App. No. 10/825,961, the full disclosure of which has been previously incorporated by reference. For example, the expandable anchor may comprise flexible polyvinyl chloride (PVC), Polyethylene, Polyether Block Amide (PEBAX), Polyethylene Terepthalate (PET), Polyester, Nylon, Polyurethanes, Polyether Block Amide (PEBAX), Polyolefins or any suitable combination thereof. Various adhesives may be used to attach anchor 516 to the catheter shaft or for any other suitable purpose. Many suitable adhesive(s) may be used, such as but not limited to, light activated acrylics, light activated cyanoacrylates, light activated silicones, heat activated adhesives, ambient curing adhesives, cyanoacrylates, epoxy adhesives, and/or polyurethane adhesives. Various parts of the catheter device may also be attached using alternative means, such as friction fitting, snap fitting, screw fitting, application of energy such as thermal or radiofrequency energy, and/or the like. [0063] Stylet 530 can be sized to pass through catheter SlO and may comprise a sharpened distal tip 532 adapted to penetrate tissue and permit catheter body 511 to enter tissue. Stylet 530 comprises a cross-sectional size, for example a diameter 534, to permit stylet 530 to slide through connector 518 A and catheter body 511. Outside diameter 534 of stylet 530 may comprise a range of diameters from about 25% to 75% of the overall outside diameter of catheter 510, for example from about 0.005" to about 0.035". Stylet 530 comprises a length 536. Length 536 may comprise many suitable lengths, and length 536 may comprise a range of lengths from about 20 to 80 cm. In many embodiments, stylet 536 may stiffen catheter 510 to facilitate placement. Stylet 530 may comprise many suitable materials such as stainless steel, tungsten, tungsten alloys, cobalt chrome alloys, nitinol, molybdenum rhenium alloys, Eligloy, MP35N, or L605, 35NLT. Additionally the stylet could be treated with materials to enhance its radiopacity such as gold, platinum, iridium, or alloys thereof or materials to enhance it lubricity such as Teflon, PTFE, orparylene.

[0064] Guidewire 540 can be sized to pass through catheter 510. In many embodiments, catheter body 511 can be advanced over guidewire 540 when stylet 530 has been removed from catheter 510. Guidewire 540 may be advanced into the disc and catheter 510 advanced over the guidewire to permit anchor 516 to attach to the disc. Guidewire 540 may comprise a cross- sectional size, for example a diameter 542, and a length 544 when elongate, as shown in Fig. 5C. Diameter 542 may comprise a range from about 0.02 mm to about 0.8 mm. Length 544 may comprise a range from about 20 to 80 cm In an exemplary embodiment, catheter 510 may comprise an overall outside diameter of about 0.038" with an injection lumen of about 0.018" that can accommodate a 0.017" guidewire and a 0.017" stylet. Guidewire 540 may comprise many suitable materials such as stainless steel, tungsten, tungsten alloys, cobalt chrome alloys, nitinol, molybdenum rhenium alloys, Eligloy, MP35N, or L605, 35NLT. Additionally the guidewire could be treated with materials to enhance its radiopacity such as gold, platinum, iridium, or alloys thereof or materials to enhance it lubricity such as Teflon, PTFE, or parylene.

[0065] Referring now to Fig. 5B, catheter 510 is shown in detail near distal end portion 514, according to embodiments of the present invention. Catheter body 511 comprises an inner lumen 511 L with an injection tube 520 disposed therein that extends from attachment 518A to distal portion 514. Injection tube 520 comprises a lumen 521 with a size, for example, an inner diameter 522, to permit stylet 530 to slide through tube 520. Injection tube 520 extends from attachment 518A to opening 515 such that fluids can be injected from attachment 518A to the disc through injection tube 520. Inner diameter 522 may comprise a range of diameters, for example a range from about 0.08 to 0.8 mm. Catheter body 511 may also comprise within lumen 11 IL an inflation tube 525, which comprises an inflation lumen 524. Inflation tube 525 and inflation lumen 524 extend from attachment 518B to anchor 516. Inflation lumen 524 comprises an inner size, for example a diameter 526. Diameter 526 may comprise a range from about 0.08 to 0.8 mm. Catheter 510 may comprise an overall outside diameter 529 in a range from about 0.38 mm (0.015¹¹) to about 1.5 mm (0.060").

[0066] Catheter injection lumen 521 may be sized to receive guidewire 540 and/or stylet 530. Such sizing of the tube lumen, stylet and guidewire provide flexible use of the kit components. For example, the user may select to insert catheter 510 with stylet 530. Guidewire 540 may also be used to insert catheter 510. The user may remove stylet 530 such that injection lumen 520 is available, and the user may insert guidewire 540 into lumen 521 and advance catheter 510 into the patient, with guidewire 540 inserted into injection lumen 520 so as to guide the catheter to the disc.

[0067] Kit 500 can be shipped to the clinician in many configurations. Kit 500 can be shipped to the clinician with stylet 530 positioned within catheter 510. In some embodiments, the kit can be shipped to the clinician with guidewire 540 and stylet 530 removed from catheter 510 and ready for placement within the catheter.

[0068] Provocative discography may be used with at least some embodiments of the present invention. Provocative discography may provide anatomical and functional information about the evaluated disc. Provocative discography may comprise an imaging procedure in which a contrast agent may be injected into the nucleus pulposus. Following injection, the disc can be evaluated on radiographs and/or computed tomography (CT).

[0069] Some embodiments of the present invention may use functional evaluation of the disc. Functional evaluation may comprise pain provocation and careful assessment of the patient's response to pain. A substance can be injected into the nucleus pulposus mat may reduce pain perceived by the patient. For example, if the patient reports a decrease in pain after injection of the substance into the disc, the disc may contribute to pain previously perceived by the patient and the defective disc may be corrected surgically.

[0070] Several substances may be injected into the nucleus pulposus to perform the functional evaluation. In some embodiments, at least one of the following substances can be introduced: an anesthetic; an analgesic; an antibiotic; ahydrating agent such as hypotonic saline, isotonic saline or hypertonic saline; a supportive agent such as a hydrogel, ethylene-vinyl alcohol copolymer, Dimethyl Sulfoxide or Tantalum; a prolotherapy agent such as sodium morrhuate, cod oil, phenol, minerals or ethyl alcohol; and other agents such as collagen, stem cells, Osteogenic Protein- 1, ethanol, alcohol, steroids, radio-opaque contrast agents, ultrasound contrast agent, Bone Morphogenetic Protein (BMP), BMP-2, BMP-4, BMP-6, BMP-7, BMP-12, Serotonin 5- HT2A receptor inhibitors, LMP-I, ΗMP-1, TGF-I, TGF-2, Rofecoxib, Ketorolac, Glucosamine, Chondroitin Sulfate, Dextrose, DMSO, non-steroidal antiinflammatory drugs, ibuprofen, naprosyn, Bextra, Vioxx, Celebrex, indomethacin, botulinum toxin, capsaicin, vanilloid agonists, vanilloid antagonists, VRl, VRL-I, steroids, methylprednisolone or chymopapain; cells, cell fragments, tissue, tissue gragments; genetic material, such as DNA, cDNA, RNA, mRNA, rRNA, siRNA, tRNA, plasmids, lentivirus, adenovirus, adeno-associated virus, or derivatives or fragments or synthetic mimics thereof; cytokines, growth factors, differentiation factors, hormones, ligands, receptors; intracellular regulatory molecules, or transcription factors, or their agonists, antagonists, activators, or inhibitors, or derivatives or fragments of synthetic mimics thereof; matrix molecules such as fibrin, collagen, proteoglycans, glycosaminoglycans, polysaccharides, elastin, or derivatives or fragments or synthetic mimics thereof; matrix- regulating molecules such as crosslinking agents, link protein, metalloproteinases, or enzymes, or their activators or inhibitors, or derivatives or fragments or synthetic mimics thereof; drugs such as statins, purmorphamine, anti-inflammatory drugs; neurotransmitting agents or neurotoxic agents or their inhibitors; MRI contrast agents; bone fillers, bone graft materials, and bone graft substitutes such as bone autograft, bone allograft, anorganic bone matrix, demineralized bone matrix, calcium phosphate, tricalcium phosphate, calcium sulfate, hydroxyapatite, bioglass, polymers, or combinations thereof; additional biologic-based, biologic derived, or biologic- mimicking substances; and substances used for controlled release of any of the above substances, such as polymers, liposomes, self-assembling monolayers, tie-layer molecules, scaffolds, or gels.

[0071] In some embodiments, the substance can be injected to alter the pH of the nucleus. In specific embodiments directed to diagnosis, raising the pH can make the nucleus and surrounding tissues more basic so as to lower the threshold of triggering nociceptive receptors. Such pH lowering substances can also be injected into the patient in therapeutic embodiments.

[0072] Figs 6A to 6D show a method 600 of accessing the interior of an intervertebral disc with an access catheter advanced into the interior of the disc with a stylet, according to embodiments of the present invention. A step 610 delivers catheter 510 with a stiffened stylet 530 from a kit as described above. A skin S is penetrated by stylet 530 and catheter 510, and the stylet and catheter are advanced distally past a vertebra V into a disc D. Disc D comprises an annulus fibrosis AF, or annulus, and a nucleus pulposus NP, or nucleus. After anchor S 16 of catheter SlO has been introduced into disc D, anchor 516 is expanded to anchor catheter 510 in disc D. In some embodiments, stylet 530 penetrates the annulus fibrosis to enter the nucleus pulposus and anchor 516 is deployed at least partially within the nucleus pulposus. A step 620 may remove the stylet and may deploy anchor 516 to anchor catheter 510 with anchor 516. A step 630 may perform a provocative discography PD to assess disc D. In some embodiments, a traditional PD may be performed and a contrast agent 631 can be injected at adapter 518A to pass through the injection lumen into the disc. A step 640 may perform a functional test. The patient may be asked to assume a position that induces pain, and a substance such as an anesthetic and/or analgesic or the like introduced, and the patient asked if the pain has decreased to determine if the disc is the source of pain experienced by the patient.

[0073] Figs 7 A to 7K show a method 700 of accessing the interior of an intervertebral disc with a needle percutaneously advanced to the interior of the disc, and a catheter advanced over a guidewire positioned with the needle, according to embodiments of the present invention. A step 705 removes stylet 530 from catheter 510 of the kit as described above. Guidewire 540 remains separate from catheter 510. A step 710 advances an introducer, or outer needle 712, and a stylet 714 through skin S of the patient. A step 715 removes stylet 714 and passes an inner needle 716 into the disc space within disc D. Inner needle 716 may penetrate the annulus fibrosis and enter the nucleus pulposus. A step 720 may perform a provocative discography, for example a traditional discography. A contrast agent 722 that can be detected by fluoroscopy and/or X-rays, MRI or the like can be injected into disc D. A step 725 may pass guidewire 540 from a proximal end of inner needle 716, through the inner needle, out a distal end of inner needle 716 and into the nucleus pulposus. A step 730 may remove inner needle 716 while guidewire 540 remains positioned in the nucleus pulposus and outer needle 712 remains positioned through skin S. A step 735 may remove outer needle 712 and guidewire 540 remains position through skin S and extends into the nucleus pulposus. A step 740 may deliver catheter 510 with the guidewire through skin S, the annulus fibrosis and into the nucleus pulposus. Catheter 510 can slide over guidewire 540 with guidewire 540 extending through adapter 518A. In some embodiments, adapter 518A may be removed while the catheter is advanced over the guidewire and attached after the catheter is placed in the disc. A step 745 removes guidewire 540 and deploys anchor 516. A step 750 may perform a provocative discography, for example if a traditional discography with a needle as described above has not been performed previously. A contrast agent 752 can be injected through catheter 510 and the disc D imaged, for example with fluoroscopy. A step 755 may perform a functional test that includes an injected substance as described above. For example, an anesthetic and/or analgesic substance may be injected through catheter 510 while anchor 516 is deployed, and patient response evaluated as described above.

[0074] It should be appreciated that the specific steps illustrated in Figs. 7A to 7K provide a particular method of accessing the interior of an intervertebral disc, according to an embodiment of the present invention. Other sequences of steps may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. Moreover, the individual steps illustrated in Figs. 7A to 7K may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.

[0075] In some embodiments, the needle can be selected in response to a location of the disc in the patient, and the needle can be selected in response to a previously placed catheter. In specific embodiments, the system is comprised within a sterile package comprising a kit, and a plurality of sterile kits are provided to the physician for assessing a plurality of discs. In specific embodiments, each kit of the plurality of kits corresponds to an evaluated disc of the plurality of discs. For example, three sterile kits can be provided to assess three adjacent discs. The decision to use either the needle or the stylet can be based on the catheter previously inserted into the adjacent disc. As the components of each kit are substantially similar, improved consistency in FAD catheter placement can be achieved.

[0076] While the above includes a complete description of the preferred embodiments of the present invention, other embodiments may fall within the spirit and scope of the invention. Therefore, the scope of the present invention should be determined with reference to the appended claims along with their full scope of equivalents.

Claims

WHAT IS CLAIMED IS:

1. A guide structure for leading a guidewire into a lumen of a catheter, said guide structure comprising: a body having a receiving end, an attachment end, and a guide channel therebetween; wherein the attachment end removably attaches an end of the catheter such that the catheter lumen is aligned with the guide channel; wherein the receiving end receives an end of the guidewire such that the guidewire can be advanced through the channel and into the lumen of the catheter.

2. A guide structure as in claim 1 , further comprising a handle on the body.

3. A guide structure as in claim 2, wherein the handle projects laterally from a location at or near the attachment end of the body.

4. A guide structure as in claim 1 , wherein the attachment end of the body is flared to provide an enlarged area for capturing the catheter.

S. A guide structure as in claim 1 , wherein a portion of the guide channel is shaped to conform to an outer distal end of the catheter.

6. A guide structure as in claim 5, wherein the shaped portion of the guide body channel has a stop for limiting insertion of the catheter.

7. A guide structure as in claim 1, wherein the receiving end of the body is flared to provide an enlarged area for receiving the guidewire.

8. A guide structure as in claim 7, wherein the flared receiving end is generally conical.

9. A guide structure as in claim 1 , wherein the body is adapted to laterally release the guidewire and/or catheter.

10. A guide structure as in claim 9, wherein the guide body channel is axially slit or splittable.

11. A guide structure as in claim 9, wherein the guide body channel is at least partially open.

12. A method for loading a guidewire into a lumen of a catheter, said method comprising: removably attaching a guide structure onto an end of the catheter, wherein the guide structure includes a channel which aligns with a port on the lumen; introducing an end of the guidewire through the channel of the guide structure into the lumen of the catheter; and removing the guide structure from the catheter.

13. A method as in claim 12, wherein removably attaching comprises inserting the catheter end through a flared attachment end of the guide structure channel.

14. A method as in claim 13, wherein the catheter end is captured in a shaped portion of the channel and engages a stop for final positioning.

IS. A method as in claim 12, wherein introducing an end of the guidewire comprises inserting the guidewire end through a flared receiving end of the guide structure channel after the guide structure has been attached to the catheter.

16. A method as in claim IS, wherein the flared receiving end has a generally conical shape.

17. A method as in claim 12, wherein removing comprises pulling the catheter and guidewire laterally from the guide structure.

18. A method as in claim 17, wherein the guidewire and catheter are pulled through an axial slit in the guide structure.

19. A method as in claim 17, wherein the guidewire and catheter are pulled through an opening in the channel.

20. A method as in claim 12, wherein removing comprises splitting the guide structure from the catheter and guidewire

21. An apparatus comprising: a guide structure; and a catheter.

22. The apparatus of claim 21 further comprising a sterile package with the guide structure pre-loaded on the catheter within a sterile package.

23. The apparatus of claim 22 wherein the guide structure is on the catheter within the sterile package such that a user may place the catheter onto a guidewire.

24. The apparatus of claim 23 wherein the catheter is positioned within a guide channel of the guide structure, and the guide structure is removably attached to the catheter.

25. The apparatus of claim 22 wherein the catheter comprises a balloon.

26. The apparatus of claim 22 wherein the catheter comprises a penetrating tip.

27. The apparatus of claim 22 wherein the guide structure is configured to protect a penetrating tip of the catheter and a balloon of the catheter.

28. The apparatus of claim 21 further comprising a guidewire.

29. The apparatus of claim 28 wherein the guidewire comprises a diameter of about 0.009 inches or below.

30. The apparatus of claim 29 wherein the catheter comprises a lumen with a diameter of about 0.011 inches or below.

31. The apparatus of claim 21 wherein the guide structure comprises a guide body having a receiving end, an attachment end, and a guide channel extending therebetween.

32. The apparatus of claim 31 wherein the receiving end comprises a diameter of about 0.2S inches.

33. The apparatus of claim 31 wherein the receiving end comprises a diameter within a range from about 0.20 to about 0.27 inches.

34. The apparatus of claim 31 wherein the guide channel comprises a diameter within a range from about 0.035 to about 0.038 inches.

35. The apparatus of claim 34 wherein the guide channel diameter is sized from about 0.0001 inches to about 0.010 inches smaller than a diameter of the catheter so as to form an interference fit.

36. The apparatus of claim 31 wherein the guide channel comprises a guidewire section with a diameter within a range from about 0.010 inches to about 0.014 inches.

37. The apparatus of claim 31 wherein the attachment end comprises a diameter within a range from about 0.035 inches to about 0.05 inches.

38. A system for accessing an interior of an intervertebral disc, said system comprising: an access catheter having at least one lumen for introducing one or more substances into the interior of the intervertebral disc; a stylet removably receivable in the at least one lumen and having a tissue- penetrating distal tip which extends from a distal end of the catheter when the stylet is in place in the lumen; and a guidewire removable receivable in the at least one lumen, wherein a user can select to percutaneously advance the access catheter to the disc interior using the stylet or can select to remove the stylet and introduce the access catheter over a guidewire to the disc interior.

39. A system as in claim 38, wherein the intervertebral disc access catheter comprises: an elongate flexible catheter body having a proximal portion and a distal portion; an inflatable anchoring balloon on the distal portion of the catheter body; an injection tube or lumen in the elongate body, said tube or lumen being adapted to removably receive either the guidewire or the stylet.

40. A system as in claim 39, wherein the intervertebral disc catheter further comprises an inflation tube or lumen in the elongate body.

41. A system as in claim 38, wherein the intervertebral disc access catheter has an outer diameter in the range from 0.4 mm to 1.5 mm, an injection lumen diameter in the range from 0.0S mm to 0.8 mm, an inflation lumen diameter in the range from 0.08 mm to 0.8 mm, and a length in the range from 10 cm to 62 cm.

42. A system as in claim 41 , wherein the guidewire has a diameter in the range from 0.02 mm to 0.8 mm.

43. A system as in claim 41 , wherein the guidewire has a length in a range from about 20 cm to about 80 cm.

44. A system as in claim 42, wherein the stylet has a diameter in the range fromθ.02 mm to 0.8 mm and a length in the range from 20 cm to 80 cm.

45. A method for accessing the interior of an intervertebral disc, said method comprising: providing a system according to claim 38; and advancing the access catheter to the disc interior using the stylet

46. A method for accessing the interior of an intervertebral disc, said method comprising: providing a system according to claim 38; percutaneously advancing a needle into the interior of the intervertebral disc; and advancing the catheter over the guidewire so that a distal end of the catheter is positioned in the disc.

47. A method for assessing the condition of an intervertebral disc, said method comprising: percutaneously advancing a needle into an intervertebral disc; assessing the condition of the disc using X-ray; advancing a guidewire through the needle in response to the condition assessed with X-ray; removing the needle over the guidewire in response to the condition assessed with X-ray; advancing a catheter over the guidewire in response to the condition assessed with X-ray, so that a distal end of the catheter is positioned in the disc; introducing at least one anesthetic or analgesic through the catheter; and further assessing the condition of the disc based on the patient's response to the anesthetic or analgesic.

48. A method for assessing the condition of an intervertebral disc having an annulus and a nucleus, said method comprising: providing a system comprising a needle, a catheter, a stylet and a guidewire, wherein the stylet is provided inside a lumen of the catheter; selecting either the guidewire or the stylet to position a distal end of the catheter through the annulus into the nucleus; and advancing the distal end of the catheter into the nucleus with either the guidewire or the stylet in response to the selection.

49. A method as in claim 48, wherein the needle is selected in response to a location of the disc in the patient.

SO. A method as in claim 48, wherein the needle is selected in response to a previously placed catheter.

51. A method as in claim 48, wherein the system is comprised within a sterile package comprising a kit, and a plurality of sterile kits are provided to the physician for assessing a plurality of discs.

52. A method as in claim S 1 , wherein each kit of the plurality kits corresponds to an evaluated disc of the plurality of discs