US20160008593A1 - Peripheral nerve field stimulator curved subcutaneous introducer needle with wing attachment specification - Google Patents

Abstract

An apparatus for use in peripheral nerve field stimulation (PNFS) whereby a plurality of curved introducer needles, of varying curvatures, are provided to permit the physician to best locate the region of oligodendrocytes that contain the A Beta fibers by matching the lumbar lordosis. A wing device is also provided that is attachable to the hub of the curved needle introducer which gives the physician better ability to maneuver the needle during insertion as well as permitting tenting of the skin. The invention benefits a large number of painful disorders arising from pathology in the cervical, thoracic, and lumbar spine. In addition, this invention can also help a large number of other conditions including but not limited to failed back surgery syndrome/post-laminectomy pain, occipital/suboccipital headaches, scar pain, post herpetic neuralgia pain, mononeuritis multiplex, and pain following joint surgery (e.g., knee, hip, shoulder).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of U.S. patent application Ser. No. 12/464,470, filed May 12, 2009, which claims the benefit of U.S. Provisional Application No. 61/052,464, filed May 12, 2008, which is incorporated herein by reference.
FIELD OF INVENTION
• The current invention relates to surgical methods, and more particularly, to a neuromodulation device.
BACKGROUND
• Peripheral Nerve Field Stimulation (PNFS) is a rapidly growing area of neuromodulation that has shown significant promise in treating patients with cervical, thoracic, and lumbar pain. This procedure, however, has relied on using electrical leads designed for stimulation of the dorsal column of the spinal cord despite the reputed target neural element being a vastly different structure. In peripheral nerve field stimulation, the neural elements that are targeted for depolarization are the terminal dendrocytes located in the subcutaneous region of the patient.
• This specific type of neuromodulation is discussed in particular detail inA Case Report of Subcutaneous Peripheral Nerve Stimulation for the Treatment of Axial Back Pain Associate with Postlaminectomy Syndrome, by Krutsch, M D, et al.,Neuromodulation: Technology at the Neural Interface, Vol. 11,Number 2, 2008.
• The introducer needle most widely used by peripheral nerve field stimulation implanters is a straight 14 gauge 4½ inch Touhy epidural needle designed for a loss of resistance approach to enter the epidural space rather than placement of electrodes into the subcutaneous region. However, achieving the proper placement of the distal end of the Touhy epidural needle for use during PNFS is very difficult for a number of reasons. The straight needle goes far too deep into the dermis or subcutaneous tissue. In addition, the small surface area of the proximal end of the Touhy epidural needle does not give the physician the required gripping surface area to properly manipulate the distal end of the needle. Furthermore, because of the straight shape of the Touhy needy, the clearance between the needle's proximal end and the physician's fingers with the skin surface make it difficult for the physician to maneuver the needle.
• Thus, there remains a need for an apparatus for use in peripheral nerve field stimulation (PNFS) that permits the physician to best locate the region of oligodendrocytes that contain the A Beta nerve fibers for inserting an electrical lead therein.
• All references cited herein are incorporated herein by reference in their entireties.
BRIEF SUMMARY
• An apparatus for supporting peripheral nerve field stimulation (PNFS) of living being tissue is disclosed. The apparatus comprises: an introducer having a curved portion; a stylet having a curved portion that is similar to the curved portion of the introducer so that the stylet can be inserted within the introducer to form an introducer needle assembly; and wherein the introducer needle assembly provides a passageway through the living being tissue for positioning an electrical lead in a region of oligodendrocytes that contain A Beta fibers when the curved portion of the introducer is passed through the living being tissue and the stylet is removed. In addition, the introducer needle will have a novel “wing-attachment” device that further facilitates the implanting physician to properly position the lead near the A Beta fibers.
• A method for positioning an electrical lead within living being tissue to support peripheral nerve field stimulation (PNFS) is disclosed. The method comprises: (a) inserting an introducer needle assembly having a curved portion through the skin of a living being at an entry location displaced away from a target region requiring PNFS; (b) providing a tactile indication of a tip of the curved introducer needle assembly as the tip moves toward the target region, and wherein the target region comprises oligodendrocytes that contain A Beta fibers; (c) tenting the skin at the entry location as the tip is moved toward the target region; (d) removing an insertable portion from the introducer needle assembly; and (e) inserting an electric lead through the introducer needle assembly so that a distal end of the electrical lead is positioned under the target location in preparation for PNFS.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
• The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein:
• FIG. 1 is an enlarged exploded view of the present invention showing the stylet, the introducer and the electrical lead (also referred to as a “PNFS lead”);
• FIG. 2 is an enlarged cross-sectional view of the present invention taken along line2-2 ofFIG. 1 and showing the stylet inserted in the introducer;
• FIG. 3 is an enlarged cross-sectional view of the present invention taken along line2-2 ofFIG. 1 showing the electrical lead replacing the stylet and inserted within the introducer;
• FIG. 4 is an enlarged cross-sectional view of the wing attachment installed on the introducer and taken along line4-4 ofFIG. 1;
• FIG. 5 is an enlarged longitudinal cross-sectional view of the electrical lead taken along line5-5 ofFIG. 1;
• FIG. 6 is an enlarged transverse cross-sectional view of the electrical lead taken along line6-6 ofFIG. 5;
• FIG. 7 shows three exemplary embodiments of the present invention having different angles of curvature;
• FIG. 8 shows how the present invention is initially used in the PNFS procedure, by marking the area of over the pain on the skin and marking the area for inserting the present invention;
• FIG. 9 depicts how the physician grasps the present invention just prior to insertion into the body;
• FIG. 10 depicts how the physician “tents” the skin during insertion of the present invention;
• FIG. 11 depicts how the physician guides the proximal end of the present invention under the skin toward the target region;
• FIG. 12 depicts the present invention, with the stylet removed, and the electrical lead being inserted through the introducer for positioning at the target region;
• FIG. 13 depicts how the physician removes the introducer once the electrical lead is properly positioned;
• FIG. 14 depicts how the electrical lead is totally embedded in the living being and connected to an embedded power source (e.g., a battery) at another location, e.g., in the buttocks;
• FIG. 15 depicts an alternative application wherein the electrical lead is partially embedded in the living being with a portion emerging from the living being for connection to an external power source (not shown); and
• FIG. 16 is a cross-sectional view of the target region showing the insertion of the present invention for properly locating the electrical lead in the region of oligodendrocytes that contain the A Beta fibers.
DETAILED DESCRIPTION
• Theinvention20 of the present application of a peripheral nerve field stimulator (PNFS) introducer needle with winged attachment is a useful invention that benefits a large number of painful disorders arising from pathology in the cervical, thoracic, and lumbar spine. In addition, thisinvention20 can also help a large number of other conditions including but not limited to failed back surgery syndrome/post-laminectomy pain, occipital/suboccipital headaches, scar pain, post herpetic neuralgia pain, mononeuritis multiplex, and pain following joint surgery (e.g., knee, hip, shoulder).
• In particular, as shown inFIG. 1, thepresent invention20 comprises an insert22 (hereinafter known as a “stylet”) that is insertable within a lumen24 (hereinafter known as an “introducer”). Both of these components comprise beveledflat tips26 and28 respectively at their distal ends. The distal tip of the introducer needle could be either sharp or blunt but for illustration purposes is shown as sharp. Thedistal end28 of theintroducer24, unlike thestylet22, is open. When thestylet22 is inserted into theintroducer24, the present invention forms anintroducer needle assembly20.
• Theintroducer needle assembly20 is similar in many ways to a 14 gauge Touhy epidural needle but is unique in its shape. As can be seen inFIGS. 1 and 7, thepresent invention20 is curved. By way of example only, some preferred angles of curvature are 15° (see20A), 25° (20B) and 35° (20C). Both thestylet22 and theintroducer24 have curved portions22A and24B, respectively, as most clearly in shown inFIG. 2, for reasons which will be discussed shortly. Suffice it to say that given that the spine normally has significant lordotic and kyphotic curves, having a curved needle better allows the implanting physician to maintain the same plane in the subdermal region wherein the A Beta fibers lie.
• Although the example embodiment has been described in terms of a needle having properties similar to a 14 gauge Touhy needle, those skilled in the art will understand thepresent invention20 can include larger and smaller gauge needles, as well as needles with different tips and compositions including but not limited to the Galt Micro Access tear away (model 010-14) and Iflow 17 gauge needle (model #5001376).
• By way of example only, the length of theintroducer needle assembly20 is approximately 3.5-6 inches. Furthermore, theintroducer24 further comprises anattachable grip30 at the introducer'sproximal end32. The grip30 (also referred to as a “wing attachment”) permits the physician the ability to more firmly grasp thepresent invention20 and to better manipulate it during the PNFS procedure. The wing attachment provides a better gripping and maneuvering surface for the physician implanter to place pressure posteriorly (towards the epidermal layer) once the needle is in the subdermal layer which helps separate the subdermal layer that is rich in A Beta fibers from the dermis and fascial layers (FIG. 16). Thegrip30 is severed31 to permit its releasable attachment to the insertion collar orhub33 of theintroducer24. For example, to install thegrip30, thegrip30 is slid over thedistal end28 of theintroducer24 and then firmly pushed over the insertion collar orhub33 until it is positioned as shown inFIG. 1. This makes a snug fit onto theintroducer24. Thegrip30 includes a pair of transverse elements or “wings”35A and35B that provide the physician with finger grips for precisely manipulating and controlling movement of theintroducer needle assembly20. The winged attachment may be of many different shapes including rectangular, square, circular oblong, and triangular. The wing attachment may be composed of a flexible material such as a plastic polymer, rubber, or malleable metal to further facilitate the implanting physician to grip the introducer and allow for clearance between the introducer and the implanting physicians fingers given that the subdermal layer is often in close approximation to epidermis. The wing attachment may also have a gripping surface such as treads or anti-skid coating material to enable the implanter to better hold the introducer needle. The wing attachment can be attached to the introducer needle in a variety of manners including snapping on, slipping on, clamping on, or clipping on. In addition, the wing device may be attached by other methods including using a glue or tape adhesive material. The wing attachment could even be comprised of a thickened sleeve that would fit around the hub of the Touhy needle. Our description is only one of many ways to attach the wing device for illustration purposes.
• It should also be noted that with thegrip30 installed on thehub33, there is an existing key that permits the physician to “track” the relative position of thecurved shaft24A when inserted into living being tissue. In particular, as shown most clearly inFIG. 1, thestylet22 includes ahub21 having anub23. When thestylet22 is properly inserted into theintroducer24, thenub23 fits into arecess25 in theintroducer hub33. This can also be seen inFIG. 2. When thenub23 is fitted into therecess25, thedistal end28 of theintroducer24 points upward, as shown inFIG. 2. Thus, if the physician rotates theintroducer24 about its longitudinal axis, he/she is always aware of which direction the curveddistal end28 is positioned by noting where thenub23 is positioned.
• As will also be discussed shortly, once theintroducer needle assembly20 is inserted into its proper location in the body, thestylet22 is removed and an electrical lead (also referred to as a “PNFS lead”)34 is inserted into theintroducer24. Once thedistal end36 of theelectrical lead34 is positioned under theskin10 at the proper target location, theintroducer24 is removed and theelectrical lead34 is secured to theskin10. Theproximal end38 of theelectrical lead34 is electrically coupled to a power source, e.g., an external power source (not shown) or to an implanted power source40 (FIG. 14).
• It should be understood that a wide variety ofmedical leads34 can be used with thepresent invention20 and theinvention20 is not limited to any particular type ofmedical lead34. By way of example only, one type of medical lead that can be used with thepresent invention20 is an electrical lead such as the Quattrode® #3063 manufactured by Advanced Neuromodulation Systems of Plano, Tex. As can be seen inFIGS. 1 and 5, theelectrical lead34 comprises a plurality of electrode elements that are in electrical communication with respective electrodes viainternal conductors42, as shown by thereference numbers41A-41B,42A-42B,43A-43B, etc. When positioned properly, there may be a 5 cm distance between the most proximal and distal electrode. When energized, localized current passes between corresponding electrode elements and through the closely-adjacent subdermal tissue. However, as mentioned previously, a wide variety ofelectrical leads34 can be used with the invention and therefore, the phrase “electrical lead34” as used throughout this application is meant to include all such types of medical leads and is not limited to that shown in the various figures. For example, another medical lead, such as the Pisces-Octad™ #3788 sold by Medtronic, Inc. of Minneapolis, Minn., can also be used.
• As can appreciated by those skilled in the art, thestylet22, while positioned in theintroducer24 when theintroducer needle assembly20 is pushed through the skin layers, thestylet22 is a solid member that acts to prevent body fluids and tissue from lodging in theintroducer24, thereby preserving the passageway that is formed by the presence of theintroducer24 for eventual displacement by theelectrical lead34.
• As mentioned previously, the introducer needle most widely used by peripheral nerve field stimulation implanters is a straight 14 gauge Touhy epidural needle designed for a loss of resistance approach to enter the epidural space rather than placement of electrodes into the subcutaneous region. In PNFS, placement of the electrodes in theelectrical lead34 closest to the target neural elements is best realized by entering the subcutaneous region with the patient in the prone position and “tenting” the needle by placing posterior pressure while advancing to the region of the patient's maximal pain. The placement of posterior pressure once the needle has entered the subdermal layer helps to separate the subdermal layer from the dermis and muscle fascial layer while advancing the needle thereby placing the lead within the layer that contains the highest concentration of A Beta fibers. “Tenting” is a novel technique that enables the implanting physician to more consistently place the electrical lead in the subdermal region. The invention described herein facilitates this novel technique. When done properly, there is minimal resistance and often this layer has an abundance of A Beta fibers allowing maximal stimulation for PNFS which ultimately maximizes pain relief for the patient.
• Heretofore, the use of the straight Touhy needle does not effect the proper placement. In contrast, the use of the curvedintroducer needle assembly20 permits this proper placement, e.g., the curved portion22A/24A matches the normal lumbar lordosis present in patients with greater than 90% of patients having a lumbar lordosis of 29-37 degrees off of the sagital plane.
• FIGS. 8-14 show an exemplary sequence for achieving positioning theelectrical lead34 using theinvention20 of the present application. With the patient positioned in a prone position, the physician marks on theskin10 the location under which the electrodedistal end36 ideally needs to be positioned; also referred to as the target location44 (FIG. 8). At another location on the skin (e.g., 3.5-4.5 inches away from the target location44), the physician marks the incision point where a small incision is made in the skin. For example, an 11-blade scalpel is used to make a 0.5cm incision46. This avoids trauma that would normally occur if thedistal end28 of theintroducer needle assembly20 were simply used to make the initial puncture. With theincision46, the physician grasps the introducer needle assembly20 (i.e., thestylet22 is already inserted therein and thegrip30 has also been previously coupled to the hub33) as shown inFIG. 9; as can be seen, the physician is able to much more easily manipulate theintroducer needle assembly20 by applying force through his middle and ring fingers on therespective wings35A/35B thereby “tenting” the skin and separating the dermis from the muscle fascial layer to place the needle in the subdermal region where the A Beta fibers are located.
• As the physician continues to insert theintroducer needle assembly20 into theskin10 towards thetarget region44, thecurved portion24A of the introducer rides close to the skin surface, permitting the physician to obtain a tactile indication of thedistal end28 with his/her other hand, as shown inFIG. 10. This has not been possible with the use of the straight Touhy needle. It should also be noted that during this process, the physician is applying a slightly upward force to “tent” the skin (see reference number48) at theentry location46. As mentioned earlier, this “tenting” involves placing posterior pressure while advancing to the region of the patient's maximal pain. By tenting and by using his/her other hand to guide thedistal end28 of theintroducer needle assembly20 to the proper subdermal location, the physician prevents thedistal end28 from accidently piercing and exiting theskin10 or going to deep and entering the muscle tissue. Thus, as mentioned previously, having theattachable grip30 facilitates the application of posterior pressure and allows for the “tenting” which in turn allows efficient and more reliable placement in the subcutaneous region.
• Once thedistal end28 of theintroducer needle assembly20 arrives at the subdermal location beneath thetarget location44, the physician removes the stylet22 (seeFIG. 11) from the introducer24 (without displacing thedistal end28 of theintroducer24 from the subdermal location) while tenting theskin10 at theincision46.
• Next, as shown inFIG. 12, the physician inserts theelectrical lead34 into theintroducer34 until thedistal end36 of thelead34 is positioned in the desired subdermal location.FIG. 16 depicts how theintroducer24 is oriented for positioning theelectrical lead34 in the region of oligodendrocytes that contain the A Beta fibers.
• While continuing to tent theskin10, the physician removes theintroducer24, as shown inFIG. 13, leaving theelectrical lead34 in place. Theelectrical lead34 is then secured in place (e.g., sutured (not shown), etc.), as shown inFIG. 14. Theproximal end38 of theelectrical lead34 is then electrically connected to an implanted power source, e.g., a rechargeable battery (e.g., 1.5 cm×5 cm×5 cm) that is implanted in, e.g., the buttocks12 (2 cm deep) to begin the PNFS. Alternatively, a portion of theelectrical lead34, including itsproximal end38, are not embedded in the living being and emerge from theskin10 to permit theproximal end38 to be electrically coupled to an external power source (not shown) to begin the PNFS.
• By way of example only, kits may be supplied with three different pre-curved needles at approximately 15° (see20A), 25° (20B) and 35° (20C) angles of curvature. A measuring tape with a marked length (for example, 4.5 inches), to facilitate positioning of the PNFS lead may also be included with the kit. In addition, having markings on the measuring tape to correspond to current lead arrays electrode to electrode distances will better enable to implanting physician to cover the patient's region of pain.
• Thus, using the present device and method of thepresent invention20, this allows physicians to better introduce the PNFSelectrical lead34 near the oligodendrocytes that contain the A Beta fibers by matching the normal kyphosis and lordosis present throughout the spine, as well as the curvature in the occipital region. In addition, the invention benefits a large number of painful disorders arising from pathology in the cervical, thoracic, and lumbar spine. In addition, this invention can also help a large number of other conditions including but not limited to failed back surgery syndrome/post-laminectomy pain, occipital/suboccipital headaches, scar pain, post herpetic neuralgia pain, mononeuritis multiplex, and pain following joint surgery (e.g., knee, hip, shoulder).
• While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

Claims (11)

1-19. (canceled)

20. A device for implanting an electrical stimulation lead for peripheral nerve stimulation within a living being, the device comprising:

an elongated curved stylet having a proximal end and a distal end;

a first hub attached to the proximal end of the stylet, the first hub having a generally rectangular prism shaped first portion with a nub extending from a first edge of the first portion, the first hub including a generally rectangular prism shaped second portion connected to the first portion;

an elongated curved introducer having a proximal end and a distal end, the introducer for receiving therein the stylet;

a second hub attached to the proximal end of the introducer, the second hub having a generally rectangular prism shaped first portion, the first portion of the second hub having a first face with the second hub attached at the first face to the proximal end of the introducer, the second hub including a second portion extending from a second face of the first portion, the second face being distal and opposite the first face of the second hub, the second portion including a recess, the recess being shaped and sized to mate with the nub extending from the first edge of the first portion of the first hub, such that when the stylet is inserted into the introducer, the nub mates with the recess; and

a grip, the grip being hollow and generally rectangular prism shaped, the grip having two opposing open ends, the grip having a first side, the first side being severed the length of the first side between the two open ends, the grip sized and shape to be releasably attached to and over the second hub with the severed first side facilitating the attachment and removal of the grip with the second hub; and

the grip including a first generally planar wing extending generally perpendicular from a second side of the grip, the first wing for at least facilitating the manipulation of the introducer by the fingers of a user.

21. The device ofclaim 20, wherein the grip includes a second generally planar wing extending generally perpendicular from a third side of the grip.

22. The device ofclaim 21, wherein the third side of the grip is opposite the second side of the grip.

23. The device ofclaim 20, wherein each of the stylet and the introducer are curved at an angle of curvature between 15° and 35°.

24. The device ofclaim 20, and further including an indicator at a proximal end the introducer that permits a user to track a relative orientation of the introducer when the introducer is passed through portions of the living being.

25. An apparatus for implanting an electrical stimulation lead for peripheral nerve stimulation within tissue a living being, the device comprising:

an elongated stylet having a proximal end and a distal end and a curved portion intermediate the proximal end and the distal end;

a first hub attached to the proximal end of the stylet, the first hub having a generally rectangular prism shaped first portion with a nub extending from a first edge of the first portion, the first hub including a generally rectangular prism shaped second portion connected to the first portion;

an elongated introducer having a proximal end and a distal end, and a curved portion intermediate the proximal end and the distal end of the introducer, the introducer for receiving therein the stylet, with the angle of curvature of the curved portion of the introducer being the same as the angle of curvature of the curved portion of the stylet;

a second hub attached to the proximal end of the introducer, the second hub having a generally rectangular prism shaped first portion, the first portion of the second hub having a first face with the second hub attached at the first face to the proximal end of the introducer, the second hub including a second portion extending from a second face of the first portion, the second face being distal and opposite the first face of the second hub, the second portion including a recess, the recess being shaped and sized to mate with the nub extending from the first edge of the first portion of the first hub, such that when the stylet is inserted into the introducer, the nub mates with the recess; and

a grip, the grip being hollow and generally rectangular prism shaped, the grip having two opposing open ends, the grip having a first side, the first side being severed the length of the first side between the two open ends, the grip sized and shape to be releasably attached to and over the second hub with the severed first side facilitating the attachment and removal of the grip with the second hub; and

the grip including a first generally planar wing extending generally perpendicular from a second side of the grip, the first wing for at least facilitating the manipulation of the introducer by the fingers of a user.

26. The apparatus ofclaim 25, wherein the grip includes a second generally planar wing extending generally perpendicular from a third side of the grip.

27. The apparatus ofclaim 26, wherein the third side of the grip is opposite the second side of the grip.

28. The apparatus ofclaim 27, wherein the curved portions of each of the stylet and the introducer are curved at an angle of curvature between 15° and 35°.

29. The apparatus ofclaim 28, and further including an indicator at a proximal end the introducer that permits a user to track a relative orientation of the introducer when the introducer is passed through portions of the living being.

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