Medical devices used in interventional radiology procedures

Abstract

A medical device for cutting soft tissue during an interventional radiology procedure comprises a hypodermic needle and a stylet located at least partially within the bore of the needle. The portion of the stylet located within the bore of the needle and the needle together form at least one fluid pathway. The stylet is movable relative to the hypodermic needle along the needle axis. The stylet is adjustable between a retracted configuration and an extended configuration. When the medical device is in the retracted configuration, the stylet head is located within the bore of the needle. When the medical device is in the extended configuration, the stylet head is located outside the bore of the needle. When the stylet is in the retracted configuration and the extended configuration, the fluid pathway enables fluid to flow from the proximal end of the needle to the distal end of the needle.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 857,063, filed on June 4, 2019, entitled MEDICAL INSTRUMENT FOR INTERVENTIONAL RADIOLOGY PROCEDURE, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to medical devices and procedures associated with interventional radiology, and more particularly to medical devices designed to enable radiologists to perform interventional radiology procedures on soft tissue. Background Art

[0004] Interventional radiology is a specialty of radiology in which minimally invasive procedures are performed using image guidance. Interventional radiology procedures can be performed for a variety of reasons. For example, some interventional radiology procedures are used for diagnostic purposes (e.g., biopsy). Other interventional radiology procedures are used for therapeutic purposes (e.g., radiofrequency ablation).

[0005] During interventional radiology procedures, radiologists use images as a guide for the use of medical devices for the procedure. Common interventional imaging methods include, for example, X-ray fluoroscopy, computed tomography (CT), ultrasound, and magnetic resonance imaging (MRI). Medical devices used in interventional radiology procedures typically include, for example, needles, catheters, drainage tubes, and guidewires. Medical devices are inserted into the patient's body through the skin, body cavity, or anatomical opening. The use of imaging methods allows the radiologist to guide these medical devices through the body to a specific area of ​​interest.

[0006] There is a need for medical devices that are specifically designed to perform interventional radiology procedures. In some cases, these specifically designed medical devices will enable radiologists to perform new interventional radiology procedures. In other cases, specifically designed medical devices will enable radiologists to perform current interventional radiology procedures in a more advanced and / or more efficient manner. In addition, imaging methods associated with interventional radiology procedures continue to evolve due to technological improvements in the underlying imaging equipment. Medical devices that are specifically designed to perform interventional radiology procedures will also enable radiologists to take advantage of these imaging developments.

[0007] Interventional radiology enables radiologists to precisely focus on specific areas of interest in the human anatomy. One of the areas of human anatomy that is relevant to interventional radiology techniques is the hand, wrist, foot, and ankle. Some common conditions / syndromes associated with this area of ​​human anatomy include, for example, carpal tunnel syndrome, tenosynovitis of the thumb, trigger finger, Dupuytren's contracture, fibroids, tarsal tunnel syndrome, and cuboid syndrome. The ability to address these conditions / syndromes using interventional radiology procedures may allow patients to avoid having to undergo open surgery, which has many benefits. For example, radiologists using interventional radiology procedures are able to visualize the patient's internal anatomy without large incisions, which makes interventional radiology less invasive and carries a lower risk of infection than open surgery. Therefore, interventional radiology enables procedures to be performed outside of the traditional hospital setting, significantly reducing the cost of diagnosis or treatment. Additionally, due to the less invasive nature of interventional radiology procedures, the procedures have the potential to reduce patient recovery time.

[0008] Therefore, there is a need for medical devices specifically designed for performing interventional radiology procedures. There is also a need to develop new interventional radiology procedures that utilize specifically designed medical devices. In particular, there is a need for medical devices specifically designed to perform interventional radiology procedures that focus on the hand, wrist, foot, and ankle. Summary of the invention

[0009] In one aspect, a medical device for cutting soft tissue during an interventional radiology procedure comprises a hypodermic needle having a needle inner surface, a needle outer surface, a needle proximal end, a needle distal end, and a needle axis. The needle inner surface defines a needle inner bore extending from the needle proximal end to the needle distal end. The needle distal end has a sharp distal tip configured to pierce soft tissue. The stylet has a stylet body, a stylet head, a stylet outer surface, a stylet proximal end, a stylet distal end, and a stylet axis. The stylet axis is coaxial with the needle axis. The stylet head is located at the stylet distal end. At least a portion of the stylet is located in the needle inner bore. The portion of the stylet located in the needle inner bore and the needle inner surface of the hypodermic needle together form at least one fluid passage. The stylet can be moved relative to the hypodermic needle along the needle axis. The stylet can be adjusted between a retracted configuration and an extended configuration. When the medical device is in the retracted configuration, the stylet head is located in the needle inner bore. When the medical device is in the extended configuration, the stylet head is located outside the inner bore of the needle. When the stylet is in the retracted configuration and the extended configuration, the fluid passage enables fluid to flow from the proximal end of the needle to the distal end of the needle. The fluid passage is configured so that the fluid in the fluid passage flows between the outer surface of the stylet and the inner surface of the needle.

[0010] On the other hand, a method for performing an interventional radiology procedure on a patient who exhibits symptoms of carpal tunnel syndrome in an affected wrist comprises orienting the affected wrist of the patient in a palmar position. A hypodermic needle is guided downward through the wrist crease of the affected wrist to a position directly superficial to the transverse carpal ligament (TCL). While the hypodermic needle is guided downward to a position directly superficial to the TCL, a fluid is injected at least intermittently through the hypodermic needle. While injecting the fluid, the hypodermic needle pierces the TCL. The fluid pushes the median nerve away from the TCL and provides a fluid pocket. The fluid pocket isolates the median nerve. A stylet is advanced through the hypodermic needle so that the distal end of the stylet extends from the distal end of the hypodermic needle. The stylet has a stylet head configured to cut the TCL. The stylet head is located at the distal end of the stylet. The stylet is positioned so that the stylet head is at least partially located within the fluid pocket. The TCL carries the stylet head. Interventional radiology procedures are performed under conditions of continuous imaging, which allows visualization of the anatomy of the affected wrist throughout the procedure.

[0011] On the other hand, a medical device for cutting soft tissue during an interventional radiology procedure includes a hypodermic needle having a needle axis and a proximal end and a distal end. The hypodermic needle includes a needle inner surface that defines a needle bore extending longitudinally from the proximal end to the distal end along the needle axis. The needle bore is configured so that a fluid can pass through the needle bore. A stylet is slidably received in the needle bore. The stylet has a proximal end and a distal end. The stylet can slide along the needle axis between a retracted position and an extended position. The distal end of the stylet includes a stylet head configured to manipulate soft tissue. The stylet head is covered by the hypodermic needle in the retracted position and protrudes from the distal end of the hypodermic needle in the extended position so that the stylet head is exposed. The medical device is configured to allow fluid to pass through the needle bore along the stylet so that the fluid is discharged from the distal end of the hypodermic needle.

[0012] Medical devices according to one or more aspects of the present disclosure may be used to perform a variety of interventional radiology procedures including, for example, carpal tunnel release, thumb tenosynovitis release, trigger finger release, tarsal tunnel release, plantar fasciitis release, fasciotomy, lavage (e.g., shoulder lavage), and tissue biopsy.

[0013] Other aspects will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a perspective view of a medical device according to the present disclosure, the medical device being in a retracted configuration.

[0015] Figure 2 yes Figure 1 A perspective view of a medical device shown in FIG. 1 , the medical device being in an extended configuration.

[0016] Figure 3 is a side view of a hypodermic needle according to the present disclosure.

[0017] Figure 4 It is along Figure 3 A cross-sectional view of a hypodermic needle taken along line 4-4 in FIG.

[0018] Figure 5 is a side view of a stylet according to the present disclosure.

[0019] Figure 6 It is along Figure 5 A cross-sectional view of the stylet taken along line 6-6 in FIG.

[0020] Figure 7 is another cross-sectional view of a stylet according to the present disclosure.

[0021] Figure 8 It is along Figure 1 A cross-sectional view of the medical device taken along line 8-8 in FIG.

[0022] Fig. 9 is a perspective view of a hypodermic needle subassembly according to the present disclosure.

[0023] Fig.10 is a side view of a collar of a hypodermic needle subassembly according to the present disclosure.

[0024] Fig.11 yes Fig.10 A cross-sectional view of the collar shown in , the section being taken along a vertical plane oriented through the middle of the collar.

[0025] Fig.12 is a perspective view of a stylet subassembly according to the present disclosure.

[0026] Fig.13 is a side view of a fluid connector of a stylet subassembly according to the present disclosure.

[0027] Fig.14 yes Fig.13 A cross-sectional view of a fluid connector shown in , the cross-sectional view being taken along a vertical plane oriented through the middle of the fluid connector.

[0028] Fig.15 is a cross-sectional view illustrating how the fluid connector is oriented within the collar when the medical device is in a retracted configuration, the cross section being taken along a vertical plane oriented intermediately through the fluid connector and the collar.

[0029] Fig.16a is a cross-sectional view illustrating how the fluid connector is oriented within the collar when the medical device is in an extended configuration, the cross section being taken along a vertical plane oriented intermediately through the fluid connector and the collar.

[0030] Fig.16b is a perspective cross-sectional view of the medical device showing how the fluid connector, collar and removable clamp interact with each other when the medical device is in a retracted configuration, the section being taken along a vertical plane oriented midway through the fluid connector and collar.

[0031] Fig.17 is a perspective cross-sectional view of the medical device showing how the fluid connector, collar and removable clamp interact with each other when the medical device is in an extended configuration, the section being taken along a vertical plane oriented midway through the fluid connector and collar.

[0032] Fig.18 It is along Fig.13 A cross-sectional view of the fluid connector taken along line 18-18 in FIG.

[0033] Fig.19 is a cross-sectional view of the medical device with the stylet removed, illustrating the flow of fluid from a syringe through a hypodermic needle.

[0034] Fig. 20 is a side view of the locking mechanism, fluid connector, and collar showing the orientation of the various components when the medical device is in a retracted configuration and the locking mechanism is engaged.

[0035] Fig.21 is a side view of the locking mechanism, fluid connector, and collar showing the orientation of the various components when the medical device is in the extended configuration and the locking mechanism is disengaged.

[0036] Fig.22a is a perspective view of a first embodiment of a stylet head according to the present disclosure.

[0037] Figure 22b yes Fig.22a 0047] A right side view of a first embodiment of a stylet head is shown in FIG. 1 , of which the left side view is a mirror image.

[0038] Fig.22c yes Figure 22a-22b A second perspective view of the first embodiment of the stylet head is shown in FIG.

[0039] Fig.23a is a perspective view of a second embodiment of a stylet head according to the present disclosure.

[0040] Figure 23b yes Fig.23a A second perspective view of a second embodiment of a stylet head is shown in FIG.

[0041] Fig.23c yes Figure 23a-23b 00147] A right side view of a second embodiment of a stylet head is shown in FIG. 10, of which the left side view is a mirror image.

[0042] Fig.23d yes Figures 23a-23c A top view of a second embodiment of a stylet head is shown in FIG.

[0043] Fig.24a is a top view of a third embodiment of a stylet head according to the present disclosure.

[0044] Figure 24b yes Fig.24a A perspective view of a third embodiment of a stylet head is shown in FIG.

[0045] Fig.24c yes Figure 24a-24b A third embodiment of a stylet tip is shown in FIG. 1 , which is a right side view of the left side view being a mirror image thereof.

[0046] Fig.25a is a perspective view of a fourth embodiment of a stylet head according to the present disclosure.

[0047] Fig.25b yes Fig.25a 0046] A right side view of a fourth embodiment of a stylet tip is shown in FIG. , of which the left side view is a mirror image.

[0048] Fig.25c yes Fig.25a -A second perspective view of the fourth embodiment of the stylet head shown in b.

[0049] Fig.26a is a right side view of a fifth embodiment of a stylet tip according to the present disclosure, of which the left side view is a mirror image.

[0050] Figure 26b yes Fig.26a A perspective view of a fifth embodiment of a stylet head is shown in FIG.

[0051] Fig.26c yes Figure 26a-26b A second perspective view of a fifth embodiment of a stylet head is shown in FIG.

[0052] Fig.27a is a right side view of a sixth embodiment of a stylet tip according to the present disclosure, of which the left side view is a mirror image.

[0053] Figure 27b yes Fig.27a A perspective view of a sixth embodiment of a stylet head is shown in FIG.

[0054] Fig.27c yes Figure 27a-27b A second perspective view of a sixth embodiment of a stylet head is shown in FIG.

[0055] Fig.28ais a perspective view of a seventh embodiment of a stylet head according to the present disclosure.

[0056] Fig.28b yes Fig.28a A second perspective view of the seventh embodiment of the stylet head is shown in FIG.

[0057] Fig.28c yes Figure 28a-28b The seventh embodiment of the stylet tip is shown in right side view, the left side view is a mirror image thereof

[0058] Fig.29a is a right side view of an eighth embodiment of a stylet tip according to the present disclosure, of which the left side view is a mirror image.

[0059] Fig.29b yes Fig.29a A perspective view of an eighth embodiment of a stylet head is shown in FIG.

[0060] Fig.29c is a perspective view of an alternative embodiment of the eighth embodiment of the stylet head.

[0061] Fig.30a is a perspective view of a ninth embodiment of a stylet head according to the present disclosure.

[0062] Fig.30b yes Fig.30a 0048] A top view of a ninth embodiment of a stylet head is shown in FIG. , the bottom view being a mirror image thereof.

[0063] Fig.30c yes Figure 30a-30b 0047] A right side view of a ninth embodiment of a stylet head is shown in FIG. , of which the left side view is a mirror image.

[0064] Fig.31a is a perspective view of a tenth embodiment of a stylet tip according to the present disclosure.

[0065] Figure 3 lb is Fig.31a A right side view of the tenth embodiment of the stylet head is shown in FIG.

[0066] Fig.31c yes Figure 31a-31b A left side view of the tenth embodiment of the stylet head is shown in FIG.

[0067] Fig.31d yes Figures 31a-31c 0014. A top view of the tenth embodiment of the stylet head is shown in , the bottom view being a mirror image thereof.

[0068] Fig.32a is a perspective view of an eleventh embodiment of a stylet tip according to the present disclosure.

[0069] Figure 32b yes Fig.32a A top view of an eleventh embodiment of a stylet head is shown in FIG.

[0070] Fig.32c yes Figure 32a-32b The right side view of the eleventh embodiment of the stylet head shown in FIG. 1 , the left side view is a mirror image thereof

[0071] Fig.32d yes Figures 32a-32c A second perspective view of the eleventh embodiment of the stylet head is shown in FIG.

[0072] Fig.33 is an image of a patient's wrist showing the anatomy associated with carpal tunnel syndrome.

[0073] Fig.34 is an illustration of a lateral view of the affected wrist in the palm position.

[0074] Fig.35 yes Fig.34 A side view illustration of an affected wrist is shown in , with an ultrasound probe positioned over the wrist.

[0075] Fig.36 yes Fig.34 Top view of the affected wrist shown in , with the affected wrist oriented along the palm position.

[0076] Fig.37 is an illustration of a hypodermic needle being inserted beveled upward into a patient's hand / wrist in a proximal to distal direction relative to the patient's hand / wrist, wherein the needle is enlarged relative to the illustrated hand / wrist to facilitate understanding.

[0077] Fig.38 is an illustration of a hypodermic needle being inserted beveled upward into a patient's hand / wrist in a distal to proximal direction relative to the patient's hand / wrist, wherein the needle is enlarged relative to the illustrated hand / wrist to facilitate understanding.

[0078] Fig.39 is an illustration of a subcutaneous injection needle inserted into a patient's hand / wrist at an angle downward in a proximal to distal direction relative to the patient's hand / wrist, wherein the needle is enlarged relative to the illustrated hand / wrist to facilitate understanding.

[0079] Fig.40 is an illustration of a hypodermic needle being inserted beveled downward into a patient's hand / wrist in a distal to proximal direction relative to the patient's hand / wrist, wherein the needle is enlarged relative to the illustrated hand / wrist to facilitate understanding.

[0080] Fig.41Ultrasound image of the carpal tunnel after a pocket of fluid has formed between the TCL and the median nerve.

[0081] Fig.42 An ultrasound image showing the anatomy involved in carpal tunnel syndrome.

[0082] In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part thereof, wherein the same reference numerals may always represent corresponding and / or similar identical parts. It should be understood that, for example, for the simplicity and / or clarity of the illustration, the figures are not necessarily drawn to scale. For example, the dimensions of certain aspects may be exaggerated relative to other aspects. In addition, it should be understood that other embodiments may be utilized. In addition, structural and / or other changes may be made without departing from the claimed subject matter. References to "claimed subject matter" throughout this specification refer to the subject matter intended to be covered by one or more claims or any part thereof, and are not necessarily intended to refer to a complete set of claims, a specific combination of claim sets (e.g., method claims, device claims, etc.) or a specific claim. DETAILED DESCRIPTION

[0083] Medical Device Overview

[0084] A medical device used during an interventional radiology procedure according to the present disclosure is Figure 1-2 10 is generally indicated by the reference numeral 10. The medical device 10 can be used to manipulate (e.g., move or cut) soft tissue during an interventional radiology procedure. The medical device 10 includes a hypodermic needle 12 and a stylet 14. Those of ordinary skill in the art will appreciate that the hypodermic needle 12 and the stylet 14 can be made of various types of materials suitable for medical use in a human patient (i.e., biocompatible). For example, the hypodermic needle 12 can be made of a metallic material (e.g., stainless steel, titanium, nitinol, or tungsten carbide) or a ceramic material (e.g., zirconium oxide, aluminum oxide, or sapphire). Similarly, the stylet 14 can be made of a metallic material (e.g., stainless steel, titanium, nitinol, or tungsten carbide) or a ceramic material (e.g., zirconium oxide, aluminum oxide, or sapphire). Those of ordinary skill in the art will appreciate that the materials used to make the hypodermic needle 12 and the stylet 14 will depend on multiple variables, including the type of interventional radiology procedure being performed and the purpose of the interventional radiology procedure.

[0085] The medical device 10 further includes a collar 16, a fluid connector 18, a removable clamp 20, and a locking mechanism 22. The hypodermic needle 12 is rigidly connected to the collar 16 to form a hypodermic needle subassembly 24, and the stylet 14 is rigidly connected to the fluid connector 18 to form a stylet subassembly 26. As discussed in more detail below, when the medical device 10 is assembled, the stylet 14 fits within the hypodermic needle 12 and the medical device 10 can be in a retracted configuration (in which the stylet is sheathed within the hypodermic needle) Figure 1 ) and an extended configuration in which a portion of the stylet extends from the hypodermic needle (shown in Figure 2 In addition, as discussed in more detail below, the stylet 14 can be rotated within the hypodermic needle 12.

[0086] like Figure 3-4 As shown, the hypodermic needle 12 has a needle inner surface 28, a needle outer surface 30, a needle proximal end 32, a needle distal end 34, and a needle axis 36. The needle inner surface 28 defines a needle inner bore 38 extending from the needle proximal end 32 to the needle distal end 34. The needle distal end 34 has a sharp distal tip 40 that is configured to pierce soft tissue, such as skin. The sharp distal tip 40 enables the hypodermic needle 12 to easily pierce the patient's skin to obtain internal access to the human anatomical structure.

[0087] In a preferred embodiment, the hypodermic needle 12 is constructed to conform to the dimensions defined by the Birmingham gauge. The Birmingham gauge is a system for specifying the thickness and / or diameter of a hypodermic needle. The Birmingham gauge is also known as the Birmingham wire gauge. The following table provides the outer diameter, inner diameter, and nominal wall thickness of a hypodermic needle as defined by the Birmingham gauge. The inner diameter and nominal wall thickness of various gauges may differ from the dimensions shown below.

[0088]

[0089]

[0090] It is expected that in certain embodiments, the medical device according to the present disclosure may substantially conform to the size of the gauge standard of any one of the Birmingham wire gauges listed in the above table. The hypodermic needle may have an outer diameter within the outer diameter range of the Birmingham gauge needle listed in the above table and / or have an inner diameter within the inner diameter range of the Birmingham gauge needle listed in the above table. In one or more embodiments, the needle within the scope of the present disclosure does not need to strictly conform to the Birmingham gauge standard. In one embodiment of the present disclosure, the outer diameter and inner diameter of the hypodermic needle 12 are smaller than a 14-gauge needle as defined by the Birmingham gauge and larger than a 28-gauge needle. In another embodiment, the outer diameter and inner diameter of the hypodermic needle 12 are smaller than a 17-gauge needle as defined by the Birmingham gauge and larger than a 23-gauge needle. In yet another embodiment, the outer diameter and inner diameter of the hypodermic needle 12 are smaller than a 18-gauge needle as defined by the Birmingham gauge and larger than a 22-gauge needle. The size of the hypodermic needle 12 will vary depending on the type of interventional radiology operation being performed and the purpose of the underlying interventional radiology operation. For example, for interventional radiology procedures performed on the hand, wrist, foot, and / or ankle, the hypodermic needle 12 may be a hypodermic needle that is smaller than a 17-gauge needle as defined by the Birmingham Rules and larger than a 23-gauge needle. This size of hypodermic needle enables the radiologist to perform interventional radiology procedures within the spatial constraints around the hand, wrist, foot, and / or ankle. One of ordinary skill in the art will appreciate that a hypodermic needle need not conform to the dimensions defined by the Birmingham Rules.

[0091] like Figure 5-6 As shown, the stylet 14 has a stylet body 42, a stylet head 44, a stylet outer surface 46, a stylet proximal end 48, a stylet distal end 50, and a stylet axis 52. The shape and size of the stylet 14 are designed to be received in the hypodermic needle 12. In one embodiment, the stylet 14 is a solid, single-piece component without any holes. The stylet outer surface 46 constitutes the periphery of the stylet 14.

[0092] The stylet 14 is configured such that after the medical device 10 is assembled, the medical device can allow fluid to pass through the needle inner hole 38 along the stylet outer surface 46 of the stylet so that the fluid is discharged from the needle distal end 34. The stylet outer surface 46 of the stylet 14 includes at least one longitudinal fluid passing surface and at least one bearing surface. Figure 5-6 In the illustrated embodiment, the stylet outer surface 46 of the stylet body 42 includes a pair of flat portions 54 and a pair of curved surface portions 55 oriented on radially opposite sides of the stylet 14. Each flat portion 54 constitutes a longitudinal fluid passing surface portion, and each curved surface portion 55 constitutes a fluid bearing surface portion. Figure 5-6As shown, the flat portion 54 is interspersed between the curved surface portions 55. Those of ordinary skill in the art will appreciate that there are a variety of ways to form the flat portion 5 on the blank from which the stylet 14 is manufactured. Those of ordinary skill in the art will further appreciate that, depending on the specific circumstances in which the medical device 10 is used and the number of longitudinal fluid-passing surfaces desired, the stylet outer surface 46 of the stylet body 42 may have only one flat portion and one curved surface portion, or more than two flat portions and more than one curved surface portion spaced apart at spaced-apart locations around the periphery of the stylet. In an alternative embodiment, the stylet outer surface of the stylet body may include a pair of grooves oriented on radially opposite sides of the stylet in place of the flat portions. In this case, each groove will constitute a longitudinal fluid-passing surface. Those of ordinary skill in the art will appreciate that the flat portions or grooves do not have to be oriented on diametrically opposite sides of the stylet.

[0093] like Figure 6 As shown, the cross-sectional shape of the periphery of the stylet 14 will be generally circular (shown in phantom) except for the flat portion 54. Thus, in one or more embodiments, the stylet 14 comprises a cylindrical blank from which material has been removed to form the flat portion. The stylet body 42 has a neutral axis NA and a center of mass C, wherein the neutral axis passes through the center of mass. Figure 6-7 As shown, the greater the distance between the center of mass C and each flat portion 54, the less material is removed from the stylet body 42 when the flat portion is formed. The less material is removed from the stylet body 42 when the flat portion 54 is formed, the greater the overall strength and rigidity of the stylet 14. At the same time, the greater the distance between the center of mass C and each flat portion 54, the less fluid can pass through the hypodermic needle 12 in a particular period of time due to the smaller fluid pathway. Fluid pathways are discussed in more detail below.

[0094] The stylet head 44 is located at the stylet distal end 50 of the stylet 14. The medical device 10 can be used in various types of interventional radiology procedures for a variety of reasons, depending on a variety of factors (e.g., the size of the hypodermic needle, the type of fluid dispensed through the medical device, the imaging method, etc.). A major factor that affects how a radiologist uses the medical device 10 is the type and / or design of the stylet head 44 of the stylet 14. The stylet head 44 enables the radiologist to perform a variety of functions within the patient's body, including cutting and / or moving soft tissue. Various designs of the stylet head 44 are discussed in more detail below.

[0095] When the medical device 10 is assembled, Figure 1-2 As shown, the stylet 14 is received within the hypodermic needle 12 in a manner such that the stylet axis 52 is coaxial with the needle axis 36. At least a portion of the stylet 14 is located within the needle bore 38. Figure 1-2In the illustrated embodiment, the majority of the stylet body 42 is located within the needle bore 38. When the medical device 10 is assembled, the stylet 14 and the hypodermic needle 12 together form a fluid passage 56, such as Figure 8 As shown. Figure 1-2 In the illustrated embodiment, the medical device 10 includes two fluid pathways 56. Each fluid pathway 56 is formed by the needle inner surface 28 of the hypodermic needle 12 and the stylet outer surface 46 of the portion of the stylet 14 that is located within the needle inner bore 38. More specifically, each fluid pathway 56 is formed by the needle inner surface 28 of the hypodermic needle 12 and the flat portion 54 of the stylet 14 that is located within the needle inner bore 38. The fluid pathways 56 enable the fluid to flow through the needle inner bore 38 of the hypodermic needle 12 along the stylet 14 so that the fluid can be discharged from the needle distal end 34. In this way, the fluid can be discharged from the needle distal end 34 even when the stylet 14 is located within the needle inner bore 38.

[0096] When the medical device 10 is assembled, the stylet 14 is movable relative to the hypodermic needle 12 along the needle axis 36. The ability of the stylet 14 to move relative to the hypodermic needle 12 along the needle axis 36 enables the medical device to be moved from a retracted configuration (in a Figure 1 ) to the extended configuration (shown in Figure 2 ). In addition, when the medical device 10 is assembled, the stylet 14 can be rotated about the needle axis 36. When the medical device is adjusted from the retracted configuration to the extended configuration or rotated about the needle axis 36, the curved surface portion 55 of the stylet outer surface 46 abuts against the needle inner surface 28 of the hypodermic needle 12. Therefore, when the stylet slides and / or rotates relative to the needle 12, the curved surface portion 55 keeps the stylet 14 centered within the needle inner bore 38.

[0097] like Fig. 9 As shown, the hypodermic needle 12 is fixedly connected to the collar 16 to form a hypodermic needle subassembly 24 . Figure 10-11 The collar 16 shown in FIG. 1 includes a collar outer surface 58 and a collar inner bore 60 extending from a collar proximal end 62 to a collar distal end 64. The collar outer surface 58 includes a slotted area 66 having a first stop 68 and a second stop 70. The collar inner bore 60 is sized and configured at the collar distal end 64 to closely receive the needle proximal end 32 of the hypodermic needle 12 and to secure the hypodermic needle relative to the collar 16. In one or more embodiments, the proximal end 32 of the hypodermic needle 12 forms a friction fit or an interference fit with the collar 16 when it is closely received within the collar inner bore 60. The needle proximal end may also be coupled to the collar by other means, such as by adhesive bonding, thermal bonding, interlocking mechanical components, etc. Suitably, the needle proximal end 32 is secured such that the needle 12 and the collar 16 are constrained to move together as a unit.

[0098] like Fig.12As shown, the stylet 14 is fixedly connected to the fluid connector 18. The stylet 14 and the fluid connector 18 partially form a stylet subassembly 26. In one embodiment, the fluid connector 18 is a Luer lock connector. In another embodiment, the fluid connector 18 is a Luer slip connector. Those of ordinary skill in the art will understand and appreciate that other types of fluid connectors can be used instead of a Luer lock connector or a Luer slip connector. Figure 13-14 The fluid connector 18 shown in FIG. 1 includes a connector outer surface 72 and a connector inner bore 74 extending from a connector proximal end 76 to a connector distal end 78. The connector outer surface 72 of the fluid connector has a channel-containing region 80 and a convex region 82. The convex region 82 of the fluid connector 18 is sized and configured to fit within the collar inner bore 60 of the collar 16, as shown in FIG. Figure 15-16a shown.

[0099] like Fig.14 As shown, the connector inner hole 74 of the fluid connector 18 includes a receiving area 84, a stylet area 88, a needle area 90 and a sealing channel 92. The receiving area 84 is configured to receive a syringe 86 and is located at the connector proximal end 76 of the connector inner hole 74. The stylet area 88 is located downstream of the receiving area 84 and is configured to tightly receive the stylet proximal end 48 of the stylet 14, thereby fixing the stylet relative to the fluid connector 18. In one or more embodiments, the stylet proximal end 48 (e.g., the curved support surface portion 55) forms a friction fit or an interference fit with the stylet area 88. The stylet proximal end may also be combined with the fluid connector in other ways, such as by adhesive bonding, thermal bonding, interlocking mechanical parts, etc. Suitably, the stylet proximal end 48 is fixed so that the stylet 14 and the fluid connector 18 are constrained to move together as a unit.

[0100] In addition, in one or more embodiments, the proximal end 48 of the stylet is fixed to the fluid connector 18 so that fluid can pass through the interface between the proximal end of the stylet and the fluid connector. For example, in the illustrated embodiment, the cross-section of the stylet region 88 is substantially circular. Therefore, although the stylet region 88 tightly receives the proximal end 48 of the stylet 14, a fluid passage 94 is formed between the fluid connector 18 and the stylet due to the flat portion 54, as shown in FIG. Fig.18 shown.

[0101] like Fig.14 As shown, the needle region 90 is downstream of the stylet region 88 and is configured to accommodate movement of the needle proximal end 32 of the hypodermic needle 12. When the medical device 10 is adjusted from the retracted configuration to the extended configuration and from the extended configuration to the retracted configuration, the needle proximal end 32 of the hypodermic needle 12 will move axially within the needle region 90. This can be Figure 16b-17. The sealing passage 92 is downstream of the needle region and is configured to accommodate a seal 94 (e.g., an O-ring). The seal 94 fits tightly within the sealing passage 92 and is sized to form a fluid-tight seal between the fluid connector 18 and the needle outer surface 30 when the medical device 10 is assembled. The seal 94 is slidably and sealingly engaged with the needle outer surface 30 so that a fluid seal is maintained when the fluid connector 18 moves axially with the stylet 14 relative to the needle 12. A collar 96 can be attached or adhered to the distal end 78 of the connector to ensure that the seal 94 remains within the sealing passage 92 when the hypodermic needle 12 moves axially relative to the seal. In general, it can be seen that the fluid connector 18, the needle 12, the seal 94, and the stylet 14 define a passage that provides sealed fluid communication between the syringe 86 and the passage 56 defined between the needle inner surface 28 and the stylet flat 54. As such, during use of the medical device 10, fluid may be directed from the syringe 86 through the needle bore 38 and along the stylet 14 so that the fluid may be expelled from the needle distal end.

[0102] Thus, the stylet 14 , fluid connector 18 , seal 94 , and ferrule 96 are fixed relative to one another and collectively form the stylet subassembly 26 .

[0103] like Figure 1-2 As shown, when the medical device 10 is assembled, the stylet subassembly 26 is connected to the hypodermic needle subassembly 24 via the removable clamp 20. Figure 16b-17 As shown, the removable clamp 20 has a proximal flange 98 and a distal flange 100. The proximal flange 98 of the removable clamp 20 is snapped into the channeled region 80 of the fluid connector 18, thereby fixing the removable clamp 20 relative to the fluid connector. The distal flange 100 of the removable clamp 20 is assembled in the slotted region 66 of the collar 16 in a manner such that the distal flange of the removable clamp can be axially moved between the first and second stops 68, 70 of the collar. When the stylet subassembly 26 is connected to the hypodermic needle subassembly 24 via the removable clamp 20, the stylet 14 can be rotated about the stylet axis 52 (which is coaxial with the needle axis 36) within the needle bore 38 of the hypodermic needle 12. In addition, the stylet subassembly 26 can be axially moved relative to the hypodermic needle subassembly 24, thereby enabling the medical device 10 to be adjusted from a retracted configuration to an extended configuration. In other words, the convex region 82 of the fluid connector 18 can move axially within the collar inner bore 60 of the collar 16 when the distal flange 100 of the removable clamp 20 slides between the first and second stops 68, 70 of the collar 16. Similarly, the proximal needle end 32 of the hypodermic needle 12 can move axially within the needle region 90 of the fluid connector 18.

[0104] like Fig.16bAs shown, when the medical device 10 is in the retracted configuration, the distal flange 100 of the removable clamp 20 is adjacent to the first stop 68 of the collar 16. When the medical device 10 is in the retracted configuration, the stylet 14 is in a retracted position, wherein the stylet head 44 is located within the needle bore 38 (e.g., Figure 1 As shown in Fig.17 As shown, when the medical device 10 is in the extended configuration, the distal flange of the removable clamp is adjacent to the second stop 70 of the collar 16. When the medical device 10 is in the retracted configuration, the stylet 14 is in an extended position, wherein the stylet head 44 is at least partially located outside the needle inner hole 38 (e.g., Figure 2 Those of ordinary skill in the art will appreciate that many factors may determine how much of the stylet head 44 is located outside of the needle bore 38. For example, the amount that the stylet 14 extends in the distal direction from the needle bore 38 will vary depending on the design of the stylet head 44 and / or the type of interventional radiology procedure being performed.

[0105] like Fig.19 As shown, the receiving area 84 of the fluid connector 18 is designed to receive a syringe 86 . Fig.19 The fluid flow in the medical device 10 is generally shown, wherein the stylet 14 is removed from the image to better illustrate the fluid flow. The syringe 86 includes an internal volume containing a fluid (e.g., lidocaine or saline or a combination thereof). At the beginning of the interventional radiology operation, the syringe 86 is received in the receiving area 84 of the fluid connector 18. When the syringe 86 is received in the syringe receiving 84, the fluid in the internal volume of the syringe is fluidly connected to the connector inner hole 74. In other words, the fluid from the internal volume of the syringe 86 can pass through the connector inner hole 74. When the syringe plunger 96 of the syringe is pressed down, the fluid from the internal volume of the syringe 86 is pressed into the connector inner hole 74 from the internal volume. The fluid from the syringe 86 enters the stylet area 88 through the receiving area 84 of the fluid connector 18. The fluid then flows through the fluid passage 94 formed between the flat portion 54 of the fluid connector 18 and the stylet 14 and enters the needle area 90. Regardless of the position of the proximal needle end 32 within the needle region 90, fluid is forced into the fluid passage 56 formed by the needle inner surface 28 of the hypodermic needle 12 and the flat portion 54 of the stylet 14 located within the needle bore 38. The seal 94 ensures that the fluid is forced into the fluid passage 56.

[0106] The fluid then flows along the stylet body 42 from the needle proximal end 32 to the needle distal end 34 through the fluid passage 56. The fluid originating from the internal volume of the syringe 86 is ultimately discharged from the medical device 10 through the sharp distal tip of the subcutaneous injection needle 12. It is noteworthy that the fluid from the syringe 86 follows this general fluid path regardless of whether the medical device 10 is in a retracted configuration, an extended configuration, or any intermediate configuration. Therefore, during an interventional radiology operation, the fluid from the syringe 86 can be injected continuously or intermittently, regardless of the position of the stylet 14 within the subcutaneous injection needle 12. As discussed in more detail below, the ability to inject fluid at any point during an interventional radiology operation enables the radiologist to more easily identify the position and / or movement of soft tissue for certain imaging methods (e.g., ultrasound). In addition, the ability to inject fluid at any point during an interventional radiology operation enables the radiologist to hydrodissect the soft tissue throughout the operation, as discussed in more detail below.

[0107] The medical device 10 may further include Figure 20-21 . When activated, the locking mechanism 22 prevents the stylet subassembly 26 from moving relative to the needle subassembly 24. In this way, the locking mechanism 22 prevents the medical device 10 from adjusting from the retracted configuration to the extended configuration when activated. The locking mechanism 22 includes a proximal locking flange 102, a distal locking flange 104, and a pull tab 106. The proximal locking flange 102 snaps into the channel area 80 of the fluid connector 18, thereby fixing the locking mechanism 22 relative to the fluid connector. The locking mechanism 22 is designed so that when engaged, the distal locking flange 104 abuts the proximal end 62 of the collar 16 and prevents the stylet subassembly 26 from moving relative to the needle subassembly 24. In one or more embodiments, in the locked configuration, additional structure associated with the collar 16 may also engage the proximal end of the flange 102. In addition, the structure associated with the collar 16 may engage one or both sides of the flange 102. As such, the locking mechanism can be configured to inhibit movement of the fluid connector relative to the collar in distal, proximal, and / or rotational directions when the locking mechanism is locked.

[0108] To release the locking mechanism 22, the radiologist pulls the pull tab 106 outward so that the distal locking flange 104 no longer abuts the collar proximal end 62. This allows the distal locking flange 104 to slide over the collar proximal end 62, thereby allowing the stylet subassembly 26 to move relative to the needle subassembly 24. In this way, the locking mechanism 22 can be released to allow the medical device 10 to be moved from the retracted configuration (in the Fig. 20 ) to the extended configuration (shown in Fig.21106). It will be appreciated by those of ordinary skill in the art that locking mechanism 22 may be a one-piece component made of a suitable material that enables a radiologist to easily release the locking mechanism by pulling tab 106 while still ensuring that the locking mechanism prevents stylet subassembly 26 from moving relative to needle subassembly 24 when the locking mechanism is engaged.

[0109] It should be understood and appreciated by those of ordinary skill in the art that other types of locking mechanisms may be used for medical devices 10 that do not include pull tabs. For example, the medical device 10 may be designed to include a twist-type locking mechanism. In such an embodiment, the removable clamp 20 and the collar 16 may be keyed in a manner such that the removable clamp (and therefore the stylet subassembly 26) cannot move axially relative to the needle subassembly 24 prior to rotating the removable clamp and the stylet subassembly. Additional alternative locking mechanisms for the medical device 10 include, but are not limited to, chucks, set screws, removable bite blocks and keys, and any other means. These locking mechanisms may be used to lock the linear movement of the stylet subassembly 26 relative to the needle assembly 24. Additionally or alternatively, these locking mechanisms may be used to lock the rotational movement of the stylet subassembly 26 around the stylet axis 52.

[0110] Those skilled in the art will further understand and appreciate that various components of the medical device 10 may be designed to provide the radiologist with an in vitro indication of the orientation of the hypodermic needle 12 (e.g., bevel up or bevel down) and the orientation of the stylet 14. For example, Fig. 9 As shown, the collar 16 includes a flat region 107 that corresponds to the location of the bevel of the sharp distal tip 40. Thus, the flat region 107 of the collar 16 provides the radiologist with an in vitro indication of the orientation of the hypodermic needle 12. The radiologist will also be able to determine the orientation of the hypodermic needle 12 via imaging methods used for interventional radiology procedures. In addition, the pull tab 106 of the locking mechanism 22 can be used to provide the radiologist with an in vitro indication of the orientation of the stylet 14. Figure 2 As shown, the projection of the pull tab 106 corresponds to the position of the stylet head 44, thereby enabling the radiologist to determine the orientation of the stylet head. This is particularly useful when the stylet 14 is in the retracted position and sheathed by the hypodermic needle 12. After the stylet 14 is in the extended position, the radiologist will also be able to determine the orientation of the stylet head 44 via imaging methods used for interventional radiology procedures.

[0111] In general, one or both of the collar 16 and the fluid connector 18 form a handle that is grasped and manipulated by the radiologist to control the medical device 10. In addition to the handle formed by the collar and / or connector, the radiologist can also use a syringe 86 (broadly, a fluid source) connected to the fluid connector 18 to grasp and manipulate the device 10. When the components at the proximal portion of the medical device 10 are considered to constitute a handle, it is obvious that the collar 16 generally forms a handle housing and the fluid connector 18 generally forms a bracket having a portion that is slidably received in the housing to move relative to the housing along the needle axis. In addition, in the illustrated embodiment, the bracket (fluid connector 18) is rotatably received in the housing (collar 16) to rotate relative to the housing around the needle axis. It should be understood that other handle configurations can be used for medical devices. In general, in a suitable handle, one of the housing and the bracket may include a fluid connector configured to connect the medical device to a fluid source, and the housing and the bracket may jointly define a passage that provides a sealed fluid communication between the connector and the inner hole of the needle. In exemplary embodiments of handles within the scope of the present disclosure, the bracket (e.g., joint 18) can be moved relative to the housing (e.g., collar 16) through a range of motion that includes a proximal position and a distal position. In addition, certain handles within the scope of the present disclosure include one or more locking mechanisms that are configured to selectively and releasably lock the bracket at one or both of the proximal position and the distal position within the range of motion.

[0112] Stylet Tip

[0113] The medical device 10 can be used in various types of interventional radiology procedures for a variety of reasons, depending on a variety of factors (e.g., the size of the hypodermic needle, the type of fluid being pushed through the medical device, the imaging method, etc.). One factor is the type and / or design of the stylet head 44 of the stylet 14. As an example, for one type of stylet head, the medical device 10 can be used to cut soft tissue to perform an imaging method (e.g., ultrasound) of one type. For another type of stylet head, the medical device 10 can be used to cut soft tissue to perform a tenolysis of the thumb tenosynovitis guided by another type of imaging method (e.g., magnetic resonance imaging (MRI)). However, for a third type of stylet head, the medical device 10 can be used to move soft tissue to enable a prostate biopsy to be performed while using an imaging method. Therefore, it should be understood by a person of ordinary skill in the art that the medical device according to the present disclosure has a wide range of uses and can be used in various types of interventional radiology procedures.

[0114] Figures 22a-22cA first design of a stylet head 44a located at the stylet distal end 50 of the stylet 14 is shown. The stylet head 44a has a curved surface 108, an atraumatic distal tip 110, and a cutting edge 112 (in a broad sense, a cutting element). The atraumatic distal tip 110 is configured so that the tip can move soft tissue without damaging or cutting the soft tissue. This ensures that the atraumatic distal tip 110 does not cut any soft tissue when the medical device 10 moves from the retracted configuration to the extended configuration. The curved surface 108, which is convex and opposite to the cutting edge 112 in this embodiment, is also atraumatic. The curved surface 108 forms an atraumatic region of the stylet head 44a, which can be used to manipulate tissue without damaging the tissue. Therefore, in the illustrated embodiment, the stylet head 44a includes a cutting edge 112 spaced apart from the atraumatic region 108 around the periphery of the stylet head. This allows the radiologist to select between cutting and moving tissue non-invasively by simply rotating the stylet until the desired side of the stylet head 44a faces the target tissue. The cutting edge 112 comprises an edge defined by a pair of converging bevels or tapered surfaces. The cutting edge 112 is sharpened so that the cutting edge can cut soft tissue. In the illustrated embodiment, the cutting edge 112 extends longitudinally along the stylet head 44a and generally faces radially outward. Like this, the stylet head 44a is designed to only cut the soft tissue adjacent to the cutting edge 112.

[0115] Radiologists can cut soft tissue adjacent to the cutting blade 112 in a variety of ways. For example, the radiologist can use the cutting blade 112 to cut soft tissue by adjusting the medical device 10 from a retracted configuration to an extended configuration or from an extended configuration to a retracted configuration. For example, it is conceivable that tissue can be cut as the stylet reciprocates along the needle between the retracted position and the extended position. Alternatively, the radiologist can use the cutting blade 112 to cut soft tissue by placing and maintaining the stylet 14 in an extended configuration and moving the entire medical device 10 (including the subcutaneous injection needle 12 and the stylet) as a unit in the proximal / distal direction and / or the superficial / deep direction, thereby cutting soft tissue. Depending on the orientation of the stylet 14 in the subcutaneous injection needle 12, the stylet may need to rotate around the stylet axis 52 to place the cutting blade 112 near the soft tissue that needs to be cut. In one or more embodiments, the extended stylet head 44a is used to cut tissue by pushing the cutting blade 112 toward the tissue. When the cutting edge 112 contacts the tissue, the radiologist can push the stylet head outward while sliding the longitudinal cutting edge along the tissue, thereby cutting through the tissue with the cutting edge. It should be understood by those skilled in the art that the above example list of how the radiologist can use the stylet head 44a to cut soft tissue is not exhaustive.

[0116] Figures 23a-23dA second design of a stylet head 44b is shown at the stylet distal end 50 of the stylet 14. The stylet head 44b is Figures 22a-22c The similarity of the stylet head 44a shown in the figure is that it includes a curved surface 108 and a longitudinal cutting edge 112. However, instead of an atraumatic distal tip, the stylet head 44b has a transverse distal cutting edge 114. Like the longitudinal cutting edge 112, the distal cutting edge 114 is sharpened so that the cutting edge can cut soft tissue. Therefore, for the stylet head 44b, the radiologist can cut the soft tissue adjacent to the longitudinal cutting edge 112 and the soft tissue adjacent to the distal cutting edge 114. The radiologist can use the stylet head 44b to cut soft tissue in a variety of ways. For example, the radiologist can use the cutting edge 112 to cut soft tissue in the same manner as the longitudinal cutting edge of the stylet head 44a described above. The radiologist can also use the distal cutting edge 114 to cut soft tissue by adjusting the medical device 10 from the retracted configuration to the extended configuration. As yet another alternative, the radiologist can use the distal cutting edge 114 to cut soft tissue by placing and maintaining the stylet 14 in the extended configuration and moving the entire medical device 10 (including the hypodermic needle 12 and the stylet) in the proximal / distal direction and / or the superficial / deep direction to cut the soft tissue. Further, the radiologist can attempt to use the distal cutting edge 114 to dissect the tissue by pushing the distal cutting edge toward the tissue and sliding the cutting edge along the tissue in a direction generally parallel to the cutting edge. It should be understood by those of ordinary skill in the art that the above list of examples of how the radiologist can use the stylet head 44b to cut soft tissue is not exhaustive.

[0117] Figures 24a-24cA third alternative design of a stylet head 44c at the stylet distal end 50b of the stylet 14b is shown. The stylet head 44c has an atraumatic distal tip 115, a curved surface 116, and a hook region 118 defined by a side recess formed in the stylet head. The hook region 118 includes a sharp hook tip 120a, a handle 122, and a cutting edge 124 that faces the proximal side in the illustrated embodiment. The hook region 118 is designed so that the sharp hook tip 120a is suspended above the cutting edge 124. The suspended nature of the sharp hook tip 120a enables the radiologist to easily see the soft tissue to be cut by the cutting edge 124 through imaging methods (e.g., ultrasound). The sharp hook tip 120a is sharpened to such an extent that the hook tip can cut through or penetrate the soft tissue. The handle 122 is configured to guide the soft tissue to the cutting edge 124. The cutting edge 124 is sharpened so that the cutting edge can cut the soft tissue. The non-invasive distal tip 115 of the stylet head 44b is configured so that the non-invasive distal tip can move soft tissue without damaging or cutting soft tissue. This ensures that when the medical device 10 moves from the retracted configuration to the extended configuration, the non-invasive distal tip 115 will not damage or cut any soft tissue. The curved surface 116 that is convex and opposite to the hook area 118 in this embodiment is also non-invasive, so that the curved surface can move soft tissue without damaging or cutting soft tissue. In this way, the stylet head 44c is designed to only cut the soft tissue hooked by the hook area 118 as the medical device 10. The radiologist can cut the soft tissue adjacent to the cutting edge 124 in a variety of ways. For example, the radiologist can use the cutting edge 124 to cut the soft tissue by adjusting the medical device 10 from the extended configuration to the retracted configuration. Alternatively, the radiologist can use the cutting blade 124 to cut soft tissue by placing and maintaining the stylet 14 in the extended configuration and moving the entire medical device 10 (including the hypodermic needle 12 and the stylet) in the proximal / distal direction and / or the superficial / deep direction, thereby cutting soft tissue. Depending on the orientation of the stylet 14 in the hypodermic needle 12, the stylet may need to rotate around the stylet axis 52 so that the soft tissue can be hooked by the hook area 118 and then cut by the cutting blade 124. In one or more embodiments, the extended stylet head 44c is used by gathering tissue in the hook area 118 and guiding it to the cutting blade 124 along the handle 122. Then the stylet 14 is moved proximally relative to the tissue to pull the cutting blade through the hooked tissue, thereby cutting the tissue. In some embodiments, the stylet 14 can also be retracted after hooking the tissue in the hooked area. The inner distal edge of needle 12 can shear through the hooked tissue as hook region 118 draws tissue into needle bore 38. One of ordinary skill in the art will appreciate that the above list of examples of how a radiologist may use stylet head 44c to cut soft tissue is not exhaustive.

[0118] Figures 25a-25cA fourth alternative design of a stylet head 44d is shown at the stylet distal end 50 of the stylet 14. Figures 24a-24c The similarity of the stylet head 44c shown in FIG. 4 is that it includes an atraumatic distal tip 115, a curved surface 116, and a hook region 118. However, instead of a sharp hook tip in the hook region 118, the stylet head 44d has an atraumatic hook tip 120b. The atraumatic hook tip 120b is atraumatic, so that the hook tip cannot cut through or penetrate soft tissue. As in the stylet head 44c, the handle 122 is designed in an inclined manner so that the handle helps to guide the soft tissue to the cutting edge 124. The radiologist can use the stylet head 44d in a manner similar to that described with respect to the stylet head 44c.

[0119] Figures 26a-26c 1 shows yet another alternative design of a stylet head 44e at the stylet distal end 50 of the stylet 14. Figures 24a-24c The stylet head 44c and Figures 25a-25c The similarity of the stylet head 44d shown in FIG. 4 is that it includes an atraumatic distal tip 115, a curved surface 116, and a hook region 118. However, unlike the stylet head 44c (having a sharp hook tip) and the stylet head 44d (having an atraumatic hook tip), the stylet head 44e does not include a suspended hook tip. Instead, the cutting edge 124 extends upward to the top surface 125. The stylet head 44d includes a handle 122 designed in such a way that the handle helps guide the soft tissue toward the cutting edge 124. The radiologist can cut the soft tissue adjacent to the cutting edge 124 in a variety of ways. For example, the radiologist can use the cutting edge 124 to cut the soft tissue by adjusting the medical device 10 from an extended configuration to a retracted configuration. Alternatively, the radiologist can use the cutting blade 124 to cut soft tissue by placing and maintaining the stylet 14 in the extended configuration and moving the entire medical device 10 (including the hypodermic needle 12 and the stylet) in the proximal / distal direction and / or the superficial / deep direction to cut soft tissue. Depending on the orientation of the stylet 14 in the hypodermic needle 12, the stylet may need to be rotated around the stylet axis 52 so that the soft tissue can be hooked by the hook area 118 and then cut by the cutting blade 124. As described above with reference to the stylet head 44c, the radiologist can also pull the tissue distally along the handle 122 toward the cutting blade 124 and then push the cutting blade through the hooked tissue to cut the tissue. It should be understood by those of ordinary skill in the art that the above example list of how the radiologist can use the stylet head 44e to cut soft tissue is not exhaustive.

[0120] Figures 27a-27cAnother alternative design of the stylet head 44f located at the stylet distal end 50 of the stylet 14 is shown. Unlike the stylet heads 44a-44e, the stylet head 44f does not include a cutting edge. Instead, the stylet head 44f is designed to enable the radiologist to move soft tissue without damaging or cutting the soft tissue. The stylet head 44f includes an atraumatic distal tip 115, a curved surface 116, and a hook region 118. The hook region 118 includes a handle 122, a non-invasive hook tip 120b, and a throat 127. The non-invasive hook tip 120b is non-invasive so that the hook tip can move soft tissue without cutting or damaging the soft tissue. Unlike the stylet heads 44c and 44d, the hook region 118 is not designed to cut soft tissue. Instead, the hook region 118 is designed to move the soft tissue hooked in the throat 127 without cutting it. Thus, the stylet head 44f is designed to enable a radiologist to hook and move soft tissue using the stylet 14. One of ordinary skill in the art will appreciate that a radiologist may use the stylet head 44f in a variety of ways during an interventional radiology procedure.

[0121] Figures 28a-28c Another alternative design of a stylet head 44g located at the stylet distal end 50 of the stylet 14 is shown. The stylet head 44g has an atraumatic distal tip 126, an upper member 128, a lower member 130, and a cutting edge 132. As used in the context of the present embodiment, it should be understood by those of ordinary skill in the art that the terms "upper" and "lower" are interchangeable because the stylet 14 can rotate about the stylet axis 52. The upper member 128 is spaced apart from the lower member 130 to form a channel 134. The length of the upper member 128 is shorter than that of the lower member 130 to enable soft tissue to enter the channel 134. The handle 135 helps to guide the soft tissue to the channel 134. The upper member 128 has a curved outer surface with a chamfered edge, and the lower member 130 has a curved outer surface with a chamfered edge. The curved outer surfaces and chamfered edges of the upper member 128 and the lower member 130 form an atraumatic surface area. The non-invasive nature of the upper and lower members 128, 130 facilitates the use of the stylet head 44g to move tissue without cutting or damaging the tissue. The upper member 128 has a member end 140 that is Figures 28a-28cIn the embodiment shown in , the non-traumatic distal tip 126 of the stylet head 44g is non-traumatic so that the end of the member cannot cut or pierce soft tissue. It should be understood by those of ordinary skill in the art that in an alternative embodiment of the stylet head 44g, the member end 128 can be sharpened to the extent that it can cut or pierce soft tissue. The cutting edge 132 is located at the distal end of the channel 134 and is sharpened so that it can cut soft tissue. The non-traumatic distal tip 126 of the stylet head 44g is configured so that the distal tip will not damage or cut soft tissue. This ensures that when the medical device 10 moves from the retracted configuration to the extended configuration, the non-traumatic distal tip 126 will not cut any soft tissue. The convex curved outer surfaces in this embodiment are configured so that they will not damage or cut soft tissue. In this way, Figures 28a-28c The stylet head 44g shown in the figure is designed to cut only the soft tissue located within the channel 134. The radiologist can cut the soft tissue within the channel 134 in a variety of ways. For example, the radiologist can gather the soft tissue in the channel when the stylet is extended, and then adjust the medical device 10 from the extended configuration to the retracted configuration, so that the soft tissue located within the channel 134 is traversed distally within the channel until it is cut by the cutting edge 132 located at the distal end of the channel. Alternatively, the radiologist can traverse the soft tissue distally within the channel 134 by placing and maintaining the stylet 14 in the extended configuration and moving the entire medical device 10 (including the hypodermic needle 12 and the stylet) along the proximal / distal direction and / or the superficial / deep direction, thereby causing the soft tissue within the channel to be cut by the cutting edge 132. Depending on the orientation of the stylet 14 within the hypodermic needle 12, the stylet may need to be rotated about the stylet axis 52 to enable the soft tissue to be located within the channel 134. It will be appreciated by those of ordinary skill in the art that the above list of examples of how a radiologist may use the stylet head 44g to cut soft tissue is not exhaustive.

[0122] Fig.29a and 29b Another alternative design of a stylet head 44h is shown. The stylet head 44h includes a distal tip 142a. Fig.29a and 29b In the illustrated embodiment, the distal tip 142a is atraumatic, thereby enabling the radiologist to move soft tissue without damaging or cutting the soft tissue. It will be appreciated by those skilled in the art that the radiologist may use the stylet head 44h having the atraumatic distal tip 142a in a variety of ways during an interventional radiology procedure. Fig.29cAn alternative embodiment of a stylet head 44h is shown. In this alternative embodiment, the distal tip 142b is sharpened to a point. The sharp distal tip 142b enables the radiologist to easily pierce or penetrate soft tissue when the stylet 14 moves in the proximal / distal direction and / or the superficial / deep direction. It should be understood by those of ordinary skill in the art that the radiologist can use the stylet head 44h with a sharp distal tip 142b in a variety of ways during an interventional radiology operation.

[0123] Figures 30a-30c Another alternative design of a stylet head 44i at the stylet distal end 50 of the stylet 14 is shown. The stylet head 44i has a top curved surface 144, a bottom curved surface 146, a first forged surface 148 (e.g., a first bevel), and a second forged surface 150 (e.g., a second bevel). The first and second forged surfaces 148, 150 intersect with each other in a manner that together form a cutting edge 152. The convex top and bottom curved surfaces 144, 146 in this embodiment are atraumatic such that the top and bottom curved surfaces do not damage or cut soft tissue. Fig.30b As shown, the first and second forged surfaces 148, 150 are symmetrical about the center plane CP. In this way, the cutting edge 152 formed by the first and second forged surfaces 148, 150 is oriented along the center plane CP. The stylet head 44i is designed to cut only the soft tissue adjacent to the cutting edge 152. The radiologist can use the cutting edge 152 to cut soft tissue in a variety of ways. For example, the radiologist can use the cutting edge 152 to cut soft tissue by adjusting the medical device 10 from the retracted configuration to the extended configuration. Alternatively, the radiologist can use the cutting edge 152 to cut soft tissue by placing and maintaining the stylet 14 in the extended configuration and moving the entire medical device 10 (including the hypodermic needle 12 and the stylet) in the proximal / distal direction and / or the superficial / deep direction, thereby cutting soft tissue. In one or more embodiments, the extended stylet head 44i is used to cut tissue by pushing the cutting edge 152 toward the tissue and then sliding the cutting edge along the tissue, thereby cutting through the tissue with the cutting edge. The distal portion of the illustrated stylet head 44i is also wedge-shaped. It is contemplated that the radiologist may use the wedge-shaped head 44i to cut tissue and / or squeeze tissue away from adjacent structures. Depending on the orientation of the stylet 14 within the hypodermic needle 12, the stylet may need to be rotated about the stylet axis 52. One of ordinary skill in the art will appreciate that the above list of examples of how a radiologist may use the stylet head 44i to cut soft tissue is not exhaustive.

[0124] Figures 31a-31d Another alternative design of a stylet head 44j is shown at the stylet distal end 50 of the stylet 14. The stylet head 44j is Figures 30a-30cThe similarity of the tube needle head 44i shown in is that it includes a top curved surface 144, a bottom curved surface 146, a first forged surface 148 and a second forged surface 150. However, unlike the tube needle head 44i, the first and second forged surfaces 148, 150 are not symmetrical about the center plane CP. Instead, the second forged surface 150 extends substantially straight from one of the flat portions 54. The cutting edge 152 deviates from the center plane CP. The forged surfaces 148, 150 converge to form a chisel-type blade. The tube needle head 44j is designed to cut only the soft tissue adjacent to the cutting edge 152. The radiologist can use the cutting edge 152 to cut soft tissue in a variety of ways. For example, the radiologist can use the cutting edge 152 to cut soft tissue by adjusting the medical device 10 from a retracted configuration to an extended configuration. Alternatively, the radiologist can use the cutting edge 152 to cut soft tissue by placing and maintaining the stylet 14 in the extended configuration and moving the entire medical device 10 (including the hypodermic needle 12 and the stylet) in the proximal / distal direction and / or the superficial / deep direction to cut soft tissue. Depending on the orientation of the stylet 14 within the hypodermic needle 12, the stylet may need to be rotated about the stylet axis 52. It should be understood by those of ordinary skill in the art that the above list of examples of how the radiologist can use the stylet head 44j to cut soft tissue is not exhaustive.

[0125] Figures 32a-32d Another alternative design of a stylet head 44k is shown at the stylet distal end 50 of the stylet 14. The stylet head 44k is similar to Figures 30a-30cThe tube stylet head 44i shown in the figure is different in that the intersection between the top curved surface 144 and the first and second forging surfaces 148, 150 forms a non-invasive corner area 154. The non-invasive corner area 154 can move soft tissue without damaging or cutting soft tissue. The non-invasive corner area 154 is oriented so that the tip is symmetrical about the center plane CP. The tube stylet head 44i is designed to cut only the soft tissue adjacent to the cutting edge 152. The radiologist can use the cutting edge 152 to cut soft tissue in a variety of ways. For example, the radiologist can use the cutting edge 152 to cut soft tissue by adjusting the medical device 10 from the retracted configuration to the extended configuration. Alternatively, the radiologist can use the cutting edge 152 to cut soft tissue by placing and maintaining the tube stylet 14 in the extended configuration and moving the entire medical device 10 (including the hypodermic injection needle 12 and the tube stylet) in the proximal / distal direction and / or the superficial / deep direction, thereby cutting soft tissue. Depending on the orientation of the stylet 14 within the hypodermic needle 12, the stylet may need to be rotated about the stylet axis 52. It will be appreciated by those of ordinary skill in the art that the above list of examples of how a radiologist may use the stylet head 44k to cut soft tissue is not exhaustive. Additionally, it will be appreciated by those of ordinary skill in the art that the stylet head 44k may have a second atraumatic tip at the intersection between the bottom curved surface 146 and the first and second forged surfaces 148, 150. Additionally, it will be appreciated by those of ordinary skill in the art that the stylet head 44j may also have one or two atraumatic tips.

[0126] Interventional Radiology Procedure - Carpal Tunnel Release

[0127] As described above, the medical device 10 can be used in various types of interventional radiology procedures for various reasons, depending on various factors (e.g., the size of the hypodermic needle, the type of fluid being pushed through the medical device, the imaging method, etc.). One interventional radiology procedure for which the medical device 10 is particularly well suited is ultrasound-guided carpal tunnel release. Fig.33 is shown in . Fig.33 The image shown is adapted from “Anatomy and Physiology” published on Openstax on May 2, 2019, which can be downloaded free of charge at http: / / cnx.org / contents / ccc4ed14-6c87-408b-9934-7a0d279d853a@8.

[0128] Carpal tunnel syndrome involves compression of the median nerve MN deep in the patient's wrist. Most commonly, the patient's median nerve MN is compressed by the transverse carpal ligament TCL (also called the flexor retinaculum). The TCL attaches to the hook of the hamate bone (labeled as element 2) and the angular bone (labeled as element 3). The TCL forms the roof of the carpal tunnel located on the palmar surface of the wrist. Fig.33 As shown, the median nerve is located deep to the TCL. Other anatomical elements are the flexor tendon FT, the angular bone (labeled as element 4), and the capitate bone (labeled as element 5).

[0129] Most often, patients who experience carpal tunnel syndrome are prescribed non-surgical methods to try to repair the compression of the median nerve. These non-surgical methods can include rest, splinting, physical therapy and corticosteroid injections. If one or more of the above-mentioned non-surgical methods cannot repair the compression of the median nerve MN, the release of the median nerve MN can be achieved by cutting the TCL. Based on experience, open surgery has been used to cut the TCL. However, open carpal tunnel release has many disadvantages. For example, open surgery is invasive and requires a large incision (often more than 60 mm in length). Large incisions can increase the risk of scar formation, infection risk and surgical complications. It also prolongs the patient's recovery period. In addition, open carpal tunnel release must be performed in an operating room and requires the presence of multiple professionals (e.g., plastic surgeons and anesthesiologists). The necessity of performing open carpal tunnel release in an operating room with multiple professionals present greatly increases the medical costs associated with the operation.

[0130] Using the medical device 10, a radiologist can perform a minimally invasive carpal tunnel release using an interventional radiology procedure, thereby avoiding the need to perform an open carpal tunnel release. The radiologist maintains direct visualization of the patient's affected wrist throughout the carpal tunnel release procedure. Direct visualization enables the radiologist to guide the medical device 10 to the appropriate location in the patient's body without damaging any nerves and / or blood vessels. Although the present disclosure describes certain exemplary methods of performing carpal tunnel release as being performed by a radiologist, it should be understood that other practitioners or healthcare professionals can perform one or more aspects of any of the methods described herein.

[0131] Direct visualization can be achieved by several different types of interventional imaging methods, including, for example, X-ray fluoroscopy, computed tomography (CT), ultrasound, and magnetic resonance imaging (MRI). The imaging method discussed throughout the remainder of the detailed description will be ultrasound. However, it will be appreciated by those of ordinary skill in the art that other suitable imaging methods may be used according to the methods disclosed herein.

[0132] At the start of the interventional radiology procedure, patients experiencing symptoms of carpal tunnel syndrome are placed in the supine or recumbent position, as appropriate. For example, the radiologist may prefer to place the patient in the supine or sitting position, depending on the available room equipment (e.g., chair or bed) and room layout. The patient's affected wrist is oriented so that the palm associated with the affected wrist faces upward (i.e., palm facing up), as shown in the figure. Fig.34 The ultrasound probe 6 is placed on the palm side of the patient's wrist to enable the radiologist to determine the cross-sectional anatomical structure of the patient's wrist, such as Fig.35 As shown. It will be appreciated by those of ordinary skill in the art that the probe can be placed longitudinally or transversely on the patient's wrist, depending on the imaging desired by the radiologist. Preferably, the ultrasound probe is a high frequency probe (e.g., a 15-7 MHz probe). For example, the ultrasound probe can be a high frequency, small footprint linear array transducer (commonly referred to as a "hockey stick" transducer). One such type of ultrasound probe is the Philips L15-7io Wideband Compact Linear Array Probe. It will be appreciated that the radiologist can hold and manipulate the ultrasound probe with one hand throughout the operation, thereby enabling the radiologist to hold and manipulate the medical device 10 with the other hand. Alternatively, an assistant (e.g., a nurse or radiology technician) can handle and manipulate the ultrasound probe throughout the operation. From Fig.42 As can be seen in the ultrasound image shown, some of the main anatomical structures that the radiologist will view are: (i) TCL (labeled "1000" in the image); (ii) tendons; and (iii) median nerve (labeled "1002"). Fig.42 In the ultrasound image shown, a portion of a hypodermic needle (labeled "1004") introduced into the patient's body can be seen.

[0133] After the radiologist visualizes the anatomy of the patient's affected wrist, a first subcutaneous injection needle (hereinafter referred to as "anesthesia needle") may be introduced through the wrist crease of the affected wrist. The wrist crease may be the proximal wrist crease PWC or the distal wrist crease DWC, such as Fig.36As shown. A fluid connector (e.g., a Luer lock) can be connected to the proximal end of the anesthetic needle. The fluid connector enables a syringe filled with anesthetic fluid to be fluidically connected to the anesthetic needle. It will be appreciated by those of ordinary skill in the art that the anesthetic fluid may comprise, for example, a mixture of saline, lidocaine, and / or triamcinolone acetonide. The anesthetic fluid is used to anesthetize the affected anatomical structure of the patient to ensure that the patient remains still during the interventional radiology procedure and to ensure the comfort of the patient during the procedure. It will be appreciated by those of ordinary skill in the art that the anesthetic needle can be a small needle because the anesthetic needle is the first subcutaneous injection needle introduced into the patient's body. The anesthetic needle can be introduced at an acute angle to the surface of the skin. It will be appreciated by those of ordinary skill in the art that the anesthetic needle can be introduced at an angle perpendicular to the surface of the skin. Under ultrasound guidance, the anesthetic needle is guided to the deep surface of the TCL while ensuring that the distal end of the subcutaneous injection needle does not engage or contact the median nerve. Depending on the circumstances, the radiologist may choose not to pierce the TCL with the anesthetic needle (i.e., remain on the superficial surface of the TCL). It will be appreciated by those of ordinary skill in the art that the anesthetic needle can be moved from proximal to distal (at a depth of 100 mm) relative to the affected wrist. Fig.37 ) or from distal to proximal relative to the affected wrist (in Fig.38 When the anesthesia needle is guided to the TCL, the anesthetic fluid is injected at least intermittently through the anesthesia needle.

[0134] After the patient is fully anesthetized, the radiologist removes the anesthetic needle from the patient and introduces the medical device 10 into the patient's body with the stylet 14 in a retracted configuration. A syringe containing a fluid is connected to the fluid connector 18 of the medical device 10. It will be appreciated by those skilled in the art that the fluid may be saline because the patient has been anesthetized. Alternatively, the fluid may be an anesthetic fluid containing, for example, a mixture of saline, lidocaine and / or triamcinolone acetonide. The medical device 10 is used to perform carpal tunnel release during interventional radiology procedures. To this end, the size of the subcutaneous injection needle 12 associated with the medical device 10 may be larger than the size of the anesthetic needle. In a preferred embodiment of performing carpal tunnel release using the method described herein, the anesthetic needle is a subcutaneous injection needle with a Birmingham wire gauge of 23 or greater. For example, in one or more embodiments, the outer diameter of the anesthetic needle is less than or equal to about 0.75 mm (e.g., less than or equal to about 0.70 mm, less than or equal to 0.65 mm). The specification number of the subcutaneous injection needle 12 associated with the medical device 10 on the Birmingham wire gauge is less than or equal to 21. For example, in one or more embodiments, the outer diameter of the hypodermic needle 12 associated with the medical device 10 is at least about 0.75 mm (e.g., at least about 0.80 mm). Using a larger needle for the hypodermic needle 12 enables the radiologist to use a larger, stronger stylet 14 to perform carpal tunnel release. However, appropriately, the cross-sectional size of the hypodermic needle 12 associated with the medical device 10 is also small enough to navigate the carpal tunnel anatomy under ultrasound guidance without inadvertently damaging, for example, nerves or blood vessels. In one or more embodiments, the outer diameter of the hypodermic needle 12 associated with the medical device 10 is less than or equal to 2.5 mm (e.g., less than or equal to about 2.0 mm, less than or equal to about 1.7 mm, less than or equal to about 1.7 mm, less than or equal to about 1.5 mm, less than or equal to about 1.4 mm). In one or more embodiments, the hypodermic needle 12 associated with the medical device 10 includes one of a Birmingham wire gauge 16, 17, 18, 19, 20, 21, and 22 gauge needle, or includes a needle having an outer cross-sectional size comparable to the needles in the group of Birmingham needles or any subset of the group of Birmingham needles. It should be understood by those of ordinary skill in the art that the hypodermic needle 12 associated with the medical device 10 can be used instead of an anesthesia needle to perform anesthesia.

[0135] The radiologist can introduce the subcutaneous injection needle 12 associated with the medical device 10 through the same entry point used to introduce the anesthesia needle. As such, in one or more embodiments, the subcutaneous injection needle 12 associated with the medical device 10 is introduced through the wrist crease of the affected wrist. Similar to the anesthesia needle, the subcutaneous injection needle 12 associated with the medical device 10 can be generally introduced in a proximal to distal direction (see Fig.37 ) or generally in a distal to proximal direction (see Fig.38) is introduced into the patient. The hypodermic needle 12 associated with the medical device 10 is introduced such that the sharp distal tip 40 is the first portion of the hypodermic needle introduced into the patient. As discussed above with respect to the anesthesia needle, the hypodermic needle 12 associated with the medical device 10 can be introduced into the patient at an angle perpendicular to the surface of the skin. However, the radiologist will most likely introduce the hypodermic needle 12 associated with the medical device 10 at an acute angle to the surface of the skin. The hypodermic needle 12 associated with the medical device 10 can be oriented with the bevel upward (e.g., Figure 37-38 ) or oriented with an inclined plane downward (as Figure 39-40 ) orientation, depending on the radiologist's preference and / or circumstances associated with the affected wrist. Throughout an interventional radiology procedure, a portion of the hypodermic needle 12 associated with the medical device 10 will be positioned in an extracorporeal location.

[0136] Under continuous ultrasound guidance, the subcutaneous injection needle 12 associated with the medical device 10 is guided along the anesthetic trajectory until the sharp distal tip 40 is immediately superficial to the TCL. In one embodiment, when the radiologist advances the subcutaneous injection needle 12 associated with the medical device 10 along the anesthetic trajectory, the fluid is intermittently injected through at least the needle inner hole 38. The intermittent injection of fluid helps the radiologist better identify the accurate positioning of the subcutaneous injection needle 12 associated with the medical device 10 relative to various anatomical structures in the patient's body. Depending on the circumstances, the fluid can be, for example, saline. Alternatively, the fluid can be an anesthetic fluid containing, for example, a mixture of saline, lidocaine and triamcinolone acetonide. Intermittent injection of a liquid containing a local anesthetic provides the additional benefit of ensuring that the patient remains anesthetized throughout the operation.

[0137] After positioning the hypodermic needle 12 so that the sharp distal tip 40 is immediately superficial to the TCL, the radiologist then advances the hypodermic needle in a deep direction while injecting fluid through the needle bore 38. This causes hydrodissection as the sharp distal tip 40 pierces the TCL. The fluid jet expelled from the hypodermic needle 12 separates the median nerve from the deep surface of the TCL. Continued injection of fluid after piercing the TCL forcibly pushes the median nerve away from the TCL (e.g., by the pressure of the injected fluid acting on the median nerve) and provides a fluid pocket 1006 that isolates the median nerve, such as Fig.41As shown. The fluid pouch provides sufficient space for the radiologist to use the medical device 10 to release the TCL without contacting and / or damaging the median nerve. In one or more embodiments, the fluid pouch has no physical blocking structure (e.g., a structure different from the distal portion of the needle shaft) between the TCL and the median nerve. For example, in some embodiments, a physical blocking structure is not deliberately introduced into the fluid pouch to form a protective device between the needle and the median nerve. Instead, in these embodiments, the fluid pouch is used to provide the radiologist with sufficient clearance to perform TCL dissection under ultrasound guidance without substantial risk of damaging the median nerve. If necessary, the fluid pouch can be maintained throughout the rest of the interventional radiology operation by injecting additional fluid through the needle inner hole 38. In one or more embodiments, the fluid pouch defines a gap of the order of 1.0 mm to 2.0 mm between the median nerve and the TCL.

[0138] The radiologist then adjusts the medical device 10 from the retracted configuration to the extended configuration so that the stylet head 44 is at least partially positioned within the fluid pocket. It will be appreciated by those of ordinary skill in the art that the radiologist may superficially move the subcutaneous injection needle 12 after the fluid pocket is formed but before adjusting the stylet 14 from the retracted configuration to the extended configuration. Alternatively, it will be appreciated by those of ordinary skill in the art that the radiologist may superficially adjust the stylet 14 from the retracted configuration to the extended configuration without superficially moving the subcutaneous injection needle 12. It will be further appreciated that various types of stylet head designs may be used to perform a carpal tunnel release procedure, as appropriate. One type of stylet head design that may be used to cut the TCL and release the median nerve is Figures 22a-22c The stylet head 44a is shown in FIG.

[0139] Depending on the orientation of the stylet head 44a relative to the hypodermic needle 12, when the medical device 10 is adjusted from the retracted configuration to the extended configuration, the stylet may need to be rotated around the stylet axis 52 to position the cutting edge 104 near the TCL. For example, the stylet 14 can be oriented in the hypodermic needle 12 so that when the medical device 10 is adjusted from the retracted configuration to the extended configuration, the cutting edge 112 is not adjacent to the TCL. Orienting the stylet 14 in this way can help the radiologist ensure that the TCL is not cut by the cutting edge 112 when the medical device 10 is adjusted from the retracted configuration to the extended configuration. After the medical device 10 is adjusted to the extended configuration, the radiologist can rotate the stylet 14 around the stylet axis 52 to position the cutting edge 112 adjacent to the TCL. The radiologist can then place the cutting edge 112 in contact with the TCL and move the cutting edge relative to the TCL to cut the TCL. It should be understood that the cutting blade 112 can be moved in a reciprocating manner while the cutting blade is pushed against the TCL. The reciprocating motion causes the cutting blade 112 of the stylet head 44a to rub against the TCL until the TCL is dissected. Alternatively, the radiologist can cut the TCL with the cutting blade 104 by adjusting the stylet 14 from the extended configuration to the retracted configuration. Using the medical device 10 in this way ensures that the stylet 14 is sheathed or received in the hypodermic needle 12 after cutting the TCL and releasing the median nerve. After the median nerve is released and the stylet head 44a is received in the hypodermic needle 10 (i.e., moved to the retracted position), the radiologist can remove the medical device 10 from the patient. Since the stylet head 44a is in the retracted position, the patient is protected when the medical device 10 is removed.

[0140] Alternatively, the stylet head 44a can be oriented in the hypodermic needle 12 so that as the stylet 14 is adjusted from the retracted configuration to the extended configuration, the cutting edge 112 is adjacent to and contacts the TCL. Orienting the stylet 14 in this manner can enable the radiologist to make a first cut on the TCL when the medical device 10 is adjusted from the retracted configuration to the extended configuration. When the medical device 10 moves from the extended configuration to the retracted configuration, the radiologist can then use the cutting edge 112 to make a second cut on the TCL. These two cuts can help ensure that the TCL is completely dissected and the median nerve is released, while also ensuring that the stylet head 44a is enclosed or stored in the hypodermic needle 12 after the TCL is cut and the median nerve is released.

[0141] While dissecting the TCL, the radiologist can intermittently inject fluid through the medical device 10. The injection of fluid assists in the dissection because the jet of fluid discharged from the needle distal end 34 of the subcutaneous injection needle 12 assists in forcing the severance of the TCL. In many cases, the TCL has thickened so that it is taut around the median nerve. Therefore, the combination of the cutting edge 112 of the stylet 14 repeatedly rubbing on the TCL and the jet of fluid discharged from the needle distal end 34 will provide sufficient force to sever the taut TCL and release the median nerve. Injecting fluid while dissecting the TCL also enables the radiologist to identify when the TCL has been dissected. After the TCL has been severed, the fluid discharged from the subcutaneous injection needle 12 will cause the TCL to vibrate. This vibration of the TCL provides the radiologist with a visual indication via ultrasound guidance that the TCL has been severed and the median nerve has been released.

[0142] The radiologist can then remove the syringe connected to the fluid connector 18 and replace it with a second syringe containing a steroid fluid. For example, the steroid fluid can be a corticosteroid, such as triamcinolone acetonide. The second syringe is connected to the fluid connector 18 so that the fluid connector (and therefore the subcutaneous injection needle 12) is connected to the steroid fluid fluid. The radiologist can then inject the steroid liquid into the patient in the local area of ​​the dissected TCL. Since the affected wrist is not "opened" like an open surgery, the steroid liquid can be easily absorbed by the patient's soft tissue. The injection of steroid fluid helps to prevent or alleviate the inflammatory response caused by the dissected TCL in the patient. This hinders the potential development of postoperative fibrosis or scar formation. Guiding the steroid fluid through the subcutaneous injection needle 12 associated with the medical device 10 rather than inserting a new subcutaneous injection needle into the patient ensures that the steroid fluid is guided to the local area where the TCL is dissected. In some cases, scarring of the TCL can lead to the recurrence of carpal tunnel syndrome. The radiologist can then remove the second syringe from the fluid connector and replace the second syringe with another syringe containing a non-steroidal fluid (e.g., an irrigation fluid such as lidocaine or saline). The syringe in fluid connection with the fluid connector enables the radiologist to flush the surgical needle with any steroid fluid before bringing the hypodermic needle 12 to the surface of the patient's skin. In some cases, bringing the steroid fluid to the surface of the patient's skin can cause skin irritation. After flushing the hypodermic needle 12, the radiologist can remove the medical device 10 from the patient and place a small bandage at the entry point if necessary.

[0143] Dissecting the TCL using the medical device 10 and the above-described interventional radiology procedure provides minimally invasive carpal tunnel release. Although multiple entry points can be used throughout the operation (e.g., the anesthesia needle can have an entry point different from the subcutaneous injection needle 12 associated with the medical device 10), the path for dissecting the TCL (or for mobilizing the median nerve and dissecting the TCL at the same time) can be provided by one and only one entry point in the patient's hand / wrist. Unlike open carpal tunnel release, in which the entry point is an incision of several centimeters or inches in length in some cases, or even some less invasive carpal tunnel releases using a smaller incision of about 4 mm or more, the entry point for dissecting the TCL in the operation described herein is only a subcutaneous needle puncture. Therefore, in one or more embodiments, the entry point of the instrument for dissecting the TCL (e.g., a subcutaneous needle puncture) has a maximum lateral dimension of less than 3.5 mm, less than 3.0 mm, less than 2.5 mm, less than 2.0 mm, less than 1.7 mm, less than 1.5 mm, or less than 1.4 mm. The small lateral dimension of the entry point helps to perform a carpal tunnel release operation in a minimally invasive manner. The minimally invasive nature helps reduce the risk of infection, enables the procedure to be performed during an outpatient visit (which helps reduce healthcare costs), greatly reduces the recovery time required for the entry point to heal, and significantly reduces the risk of scarring (both on the surface of the skin and within the site of the dissected TCL).

[0144] It should be understood that other types of stylet head designs for performing carpal tunnel release may be employed in addition to stylet head 44a. Depending on the positioning of stylet head 44 and the cutting edge on the stylet head, one of ordinary skill in the art will appreciate that the exact operation for dissecting the TCL may be different from the operation provided above. For example, if stylet head 44c is used to dissect the TCL, the stylet 14 may be used in such a manner that the TCL is positioned within hook region 118 so that the cutting edge 124 can dissect the TCL.

[0145] Other interventional radiology procedures

[0146] It is obvious to those skilled in the art that the medical device 10 is suitable for other types of image-guided radiology operations involving manipulation of soft tissue. Generally speaking, during any image-guided radiology operation, the radiologist at least intermittently views the target anatomical structure in imaging forms such as ultrasound, Mill, etc. In some embodiments, the radiologist uses an anesthesia needle to establish an anesthesia trajectory before introducing the medical device 10. In order to introduce the medical device, the sharp tip of the hypodermic needle 12 pierces the patient's skin or otherwise enters the patient's body through an appropriate entry point. Then the needle 12 is advanced under image guidance until the distal end of the needle is located at the target site. At any time when the needle 12 is advanced, the fluid can be continuously or intermittently distributed along the stylet 14 through the needle, thereby being discharged from the distal end of the needle to achieve any desired effect, such as hydrodissection, therapeutic treatment of tissue, anesthesia, image enhancement or improved visualization. When the imaging shows that the distal end of the needle is located at the target site, the stylet 14 with the desired stylet head is advanced to the extended configuration through the needle inner hole. Subsequently, the medical device 10 moves as a unit or the stylet 14 moves relative to the needle 12 to manipulate the target tissue under image guidance as needed during operation. At any time when the stylet tip is used to manipulate tissue, fluid can be continuously or intermittently dispensed through the needle along the stylet 14 so as to be discharged from the distal end of the needle to achieve a desired effect, such as hydrodissection, therapeutic treatment of tissue, anesthesia, image enhancement, or improved visualization. A syringe containing any desired fluid can be connected to the fluid connector 18 and dispensed through the needle 12 during the operation. When the operation is completed, the needle can be removed from the patient.

[0147] Since the needle point is the only entry point for the procedure, suturing is generally not required and patient recovery may involve minimal pain and discomfort. Unlike open surgery, which includes minimally invasive surgical procedures using smaller incisions of the order of 4 mm or greater, the entry point for performing the procedure using the medical device 10 is only a hypodermic needle puncture. Therefore, in one or more embodiments, the entry point (e.g., a hypodermic needle puncture) for performing an interventional radiology procedure using the medical device 10 has a maximum lateral dimension of less than 3.5 mm, less than 3.0 mm, less than 2.5 mm, less than 2.0 mm, less than 1.7 mm, less than 1.5 mm, or less than 1.4 mm. The small lateral dimensions of the entry point facilitate the minimally invasive implementation of the procedure. The minimally invasive nature helps reduce the risk of infection, enables the procedure to be performed during an outpatient visit (which helps reduce medical costs), significantly reduces the recovery time required for the entry point to heal, and significantly reduces the risk of scarring (at the surface of the skin and the location of the internal anatomical TCL).

[0148] Among other interventional radiology procedures that may be performed using the medical device 10, it is expressly contemplated that the device may be used in the general manner described above to perform tenosynovitis release of the thumb, trigger finger release, tarsal tunnel release, plantar fascia release, arm or leg fasciotomy, lavages (e.g., shoulder lavages), and tissue biopsies (e.g., pancreatic biopsies). In view of the foregoing, the basic methods of using the medical device 10 to perform these and other procedures will be apparent to those skilled in the art.

[0149] For example, to perform a tenosynovitis release procedure for the thumb, a hypodermic needle 12 is introduced into the hand or wrist under image guidance toward the affected tendon extending beside the wrist near the thumb. When the distal end of the needle is at the target site, a stylet having the desired stylet head configuration is advanced to an extended configuration and used to release the affected tendon (with or without the aid of hydrodissection or other therapeutic or image-enhancing fluid dispensed through the needle bore during the procedure).

[0150] To perform a trigger finger release, a hypodermic needle 12 is introduced into the hand toward the annular ligament under image guidance. When the distal end of the needle is at the target site (e.g., deep to the annular ligament), a stylet having the desired stylet head configuration is advanced to an extended configuration and used to release the affected tendon (with or without the aid of hydrodissection or other therapeutic or image-enhancing fluid dispensed through the needle bore during the procedure).

[0151] To perform a tarsal tunnel release, a hypodermic needle 12 is introduced into the foot or ankle toward the tarsal ligament under image guidance. When the distal end of the needle is at the target site, a stylet having the desired stylet head configuration is advanced to an extended configuration and used to release the affected tendon (with or without the aid of hydrodissection or other therapeutic or image-enhancing fluid dispensed through the needle bore during the procedure).

[0152] To perform a plantar fasciitis release procedure, a hypodermic needle 12 is introduced into the foot or ankle toward the plantar fascia under image guidance. When the distal end of the needle is at the target site, a stylet having the desired stylet head configuration is advanced to an extended configuration and used to release the plantar fascia (with or without the aid of hydrodissection or other therapeutic or image-enhancing fluid dispensed through the bore of the needle during the procedure).

[0153] To perform an arm or leg fasciotomy, a hypodermic needle 12 is introduced into the arm or leg under image guidance at a plurality of locations spaced longitudinally along the arm or leg toward the corresponding fascia. When the distal end of the needle is at each target site, a stylet having the desired stylet head configuration is advanced to an extended configuration and used to release the fascia (with or without the aid of hydrodissection or other therapeutic or image-enhancing fluids dispensed through the needle bore during the procedure).

[0154] To perform shoulder lavage, a hypodermic needle 12 is introduced into the arm or shoulder under image guidance. (It should be understood that when other lavages are to be performed, the needle is introduced into other body parts). Using the medical device, conventional lavage techniques can generally be used to perform shoulder lavage, except for the use of the stylet head to destroy the calcified deposits in the shoulder. During this operation, an irrigating fluid (e.g., saline) is used to flush calcium from the joint area along the stylet through the needle. Subsequently, the steroid is introduced into the joint area (e.g., into the bursa) along the stylet through the needle.

[0155] During a biopsy, a hypodermic needle 12 is introduced under image guidance to the site of the anatomical structure to be biopsied. When the distal end of the needle is at the target site, a stylet having the desired stylet head configuration is advanced to an extended configuration and used to extract a sample of the target tissue. In one or more embodiments, the tissue sample is retained on the stylet head and then retracted. The collected tissue sample is then safely enclosed within the needle until the medical device is removed.

[0156] When introducing elements of the present invention or the preferred embodiments thereof, the words "a", "an", "the" and "said" are intended to mean that there are one or more of such elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0157] In view of the above, it can be seen that several objects of the present invention are achieved and other advantageous results are obtained. Since various changes can be made in the above products and methods without departing from the scope of the present invention, it is intended that all contents contained in the above description should be interpreted as illustrative rather than restrictive.

Claims

1. A medical device for cutting soft tissue in an interventional radiology procedure, the medical device comprising: a hypodermic needle having a needle inner surface defining a needle bore extending from the needle proximal end to the needle distal end, a needle outer surface, a needle proximal end, a needle distal end, and a needle axis, the needle inner surface defining a needle bore extending from the needle proximal end to the needle distal end, the needle distal end having a sharp distal tip configured to pierce soft tissue; A stylet, the stylet having a stylet body, a stylet head, an outer surface of the stylet, a proximal end of the stylet, a distal end of the stylet and a stylet axis, wherein the stylet axis is coaxial with the needle axis, the stylet head is located at the distal end of the stylet, at least a portion of the stylet is located in the needle inner hole, the portion of the stylet located in the needle inner hole and the inner surface of the subcutaneous injection needle together form at least one fluid passage, the stylet can move along the needle axis relative to the subcutaneous injection needle, and the stylet The medical device is adjustable between a retracted configuration and an extended configuration, wherein when the medical device is in the retracted configuration, the head of the stylet is located inside the inner hole of the needle; when the medical device is in the extended configuration, the head of the stylet is located outside the inner hole of the needle; when the stylet is in the retracted configuration and in the extended configuration, the fluid passage enables the fluid to flow from the proximal end of the needle to the distal end of the needle, and the fluid passage is configured so that the fluid in the fluid passage flows between the outer surface of the stylet and the inner surface of the needle; wherein the sharp distal tip enables the hypodermic needle to easily penetrate the patient's skin to gain internal access to human anatomical structures; and Wherein, the acupuncture point is the only entry point for the interventional radiology procedure; The stylet proximal end extends in a proximal direction from the needle proximal end, and the medical device further includes a fluid connector configured to be removably connected to a syringe, the fluid connector being connected to the stylet proximal end of the stylet.

2. The medical device according to claim 1, wherein: The hypodermic needle is constructed to conform to the dimensions defined by the Birmingham Rules.

3. The medical device according to claim 2, wherein: The hypodermic needle is smaller than a 14 gauge needle as defined by the Birmingham regulations and larger than a 28 gauge needle as defined by the Birmingham regulations.

4. The medical device according to claim 3, wherein: The hypodermic needle is smaller than a 17 gauge needle as defined by the Birmingham regulations and larger than a 23 gauge needle as defined by the Birmingham regulations.

5. The medical device according to claim 1, wherein: The fluid connector is a Luer lock connector.

6. The medical device according to claim 1, wherein: The medical device also includes a collar fixedly connected to the proximal end of the needle.

7. The medical device according to claim 6, wherein: The collar surrounds at least a portion of the stylet, and the stylet and the fluid connector are movable relative to the collar.

8. The medical device according to claim 7, wherein: The collar is configured to receive at least a portion of the fluid fitting.

9. The medical device according to claim 8, wherein: The medical device also includes a collar assembly including the collar and at least one O-ring positioned within the collar.

10. The medical device according to claim 9, wherein: The collar is fluidly connected to the fluid fitting.

11. The medical device according to claim 1, wherein: The medical device is adjustable between a locked configuration in which the stylet is fixed relative to the hypodermic needle and an unlocked configuration in which the stylet is movable relative to the hypodermic needle.

12. The medical device according to claim 1, wherein: The medical device is adjustable from a locked configuration, in which the stylet is fixed relative to the hypodermic needle, to an unlocked configuration, in which the stylet is movable relative to the hypodermic needle.

13. The medical device according to claim 12, wherein: The medical device is configured such that fluid can flow through the fluid passageway when the medical device is in the locked configuration and the unlocked configuration.

14. The medical device according to claim 13, wherein: The medical device is configured such that when the medical device is in the locked configuration, the stylet is in the retracted configuration.

15. The medical device according to claim 14, wherein: The stylet is rotatable about the stylet axis.

16. The medical device according to claim 15, wherein: The medical device is configured to be adjustable from the locked configuration to the unlocked configuration by rotating the stylet about the stylet axis.

17. The medical device according to claim 1, wherein: The stylet is a solid, one-piece component without any holes.

18. The medical device according to claim 17, wherein: The stylet outer surface of the stylet body includes at least one flat portion extending through the needle inner bore, the flat portion of the stylet and the needle inner surface of the hypodermic needle together forming the fluid passageway.

19. The medical device according to claim 17, wherein: The stylet outer surface of the stylet body includes at least one notched region extending through the needle inner bore, the notched region of the stylet and the needle inner surface of the hypodermic needle together forming the fluid passageway.

20. A medical device for cutting soft tissue during an interventional radiology procedure, the medical device comprising: a hypodermic needle having a needle axis and a proximal end and a distal end, the hypodermic needle including a needle inner surface defining a needle bore extending longitudinally along the needle axis from the proximal end to the distal end, the needle bore being configured to allow fluid to pass through the needle bore; a stylet slidably received in the needle bore, the stylet having a proximal end and a distal end, the stylet being slidable along the needle axis between a retracted position and an extended position, the distal end of the stylet comprising a stylet head configured to manipulate soft tissue, the stylet head being covered by the hypodermic needle in the retracted position and protruding from the distal end of the hypodermic needle in the extended position to expose the stylet head; wherein the medical device is configured to allow fluid to pass through the needle inner hole along the stylet so that the fluid is discharged from the distal end of the hypodermic needle; The stylet head is configured to cut the transverse carpal ligament; The stylet proximal end extends in a proximal direction from the needle proximal end, and the medical device further includes a fluid connector configured to be removably connected to a syringe, the fluid connector being connected to the stylet proximal end of the stylet.

21. The medical device according to claim 20, wherein: The stylet includes a bearing surface that slidingly engages the hypodermic needle.

22. The medical device according to claim 21, wherein: The stylet includes a longitudinal fluid passage surface, at least a portion of which is opposite and spaced apart from the needle interior surface.

23. The medical device of claim 22, wherein: The longitudinal fluid passage surface and the needle inner surface define a fluid passage configured to allow fluid to pass through the needle inner bore along the stylet.

24. The medical device of claim 23, wherein: The stylet has a perimeter, and the bearing surface includes at least first and second longitudinal bearing surface portions at spaced locations about the perimeter.

25. The medical device of claim 24, wherein: The longitudinal fluid passage surface comprises at least a first longitudinal fluid passage surface portion and a second longitudinal fluid passage surface portion at spaced apart locations around the perimeter.

26. The medical device of claim 25, wherein: The first and second longitudinal fluid passage surface portions are interposed between the first and second longitudinal support surface portions.

27. The medical device of claim 22, wherein: The longitudinal fluid passing surface comprises a flat portion.

28. The medical device of claim 22, wherein: The hypodermic needle has a length along the needle axis and the longitudinal fluid passage surface has a length along the needle axis, the length of the longitudinal fluid passage surface being greater than the length of the hypodermic needle.

29. The medical device of claim 20, wherein: The outer diameter of the hypodermic needle is less than 2.0 mm.

30. The medical device of claim 29, wherein: The outer diameter is less than 1.5 mm.

31. The medical device of claim 20, wherein: The stylet head includes an atraumatic region.

32. The medical device of claim 31, wherein: The stylet has a stylet axis, and the stylet head further includes a cutting edge, the cutting edge and at least a portion of the atraumatic region being angularly spaced apart about the stylet axis.

33. The medical device of claim 32, wherein: The cutting edge and at least a portion of the atraumatic region are spaced apart along the needle axis.

34. The medical device of claim 20, wherein: The distal portion of the stylet includes an atraumatic distal tip.

35. The medical device of claim 20, wherein: The stylet head includes a longitudinal cutting edge along a perimeter of a distal portion of the stylet.

36. The medical device of claim 20, wherein: The stylet head has a sharp distal tip.

37. The medical device of claim 20, wherein: The stylet head includes an undercut that forms a hook region.

38. The medical device of claim 37, wherein: The stylet head includes a cutting edge at an interior position of the hook region.

39. The medical device of claim 38, wherein: The cutting edge faces generally proximally.

40. The medical device of claim 37, wherein: The hook region includes a proximally facing tip that is sharpened to a point.

41. The medical device of claim 32, wherein: The stylet head includes an undercut and the cutting edge includes a proximally facing cutting edge at a distal portion of the undercut.

42. The medical device of claim 20, further comprising a handle comprising a housing secured to the proximal end of the needle and a bracket secured to the proximal end of the stylet.

43. The medical device of claim 42, wherein: The housing has an interior extending along the needle axis, and at least a portion of the carrier is slidably received within the interior of the housing to move relative to the housing along the needle axis.

44. The medical device of claim 43, wherein: One of the housing and the bracket includes a fluid connector configured to couple the medical device to a fluid source.

45. The medical device of claim 44, wherein: The handle includes a passageway providing sealed fluid communication between the hub and the needle bore.

46. ​​The medical device of claim 43, wherein: The bracket is movable relative to the housing within a range of motion that includes a proximal position and a distal position.

47. The medical device of claim 46, wherein: The handle includes a locking mechanism configured to releasably lock the bracket in at least one of the proximal position and the distal position.

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