Patent Application
20220096116
The present disclosure generally relates to medical instruments and procedures associated with interventional radiology, and more specifically, to medical instruments designed to enable radiologists to perform interventional radiology procedures on soft tissue.
Interventional radiology is a radiology specialty in which minimally invasive procedures are performed using image guidance. Interventional radiology procedures may be performed for a variety of reasons. For example, some interventional radiology procedures are done for diagnostic purposes (e.g., biopsy). Other interventional radiology procedures are performed for treatment purposes (e.g., radiofrequency ablation).
During an interventional radiology procedure, a radiologist uses images as guidance for operating with medical instruments. Common interventional imaging methods include, for example, X-ray fluoroscopy, computed tomography (CT), ultrasound, and magnetic resonance imaging (MRI). Medical instruments used in interventional radiology procedures typically include, for example, needles, catheters, drains, and guide-wires. The medical instruments are inserted into a patient's body through the skin, through a body cavity, or through an anatomical opening. The use of an imaging method allows the radiologist to guide these medical instruments through the body to a specific area of interest.
Medical instruments specifically designed for performing interventional radiology procedures are needed. In some instances, these specifically designed medical instruments will enable radiologists to perform new interventional radiology procedures. In other instances, the specifically designed medical instruments will enable radiologists to perform current interventional radiology procedures in a more advanced and/or more efficient manner. Additionally, imaging methods associated with interventional radiology procedures continue to advance because of technological improvements in underlying imaging equipment. Medical instruments specifically designed for performing interventional radiology procedures will also enable radiologists to capitalize on these imaging advancements.
Interventional radiology enables a radiologist to precisely focus on a specific area of interest of the human anatomy. One area of the human anatomy relevant to interventional radiology techniques are hands, wrists, feet, and ankles. Some common conditions/syndromes associated with this area of the human anatomy include, for example, carpal tunnel syndrome, De Quervain's syndrome, trigger fingers, Dupuytren contracture, fibromas, tarsal tunnel syndrome, and cuboid syndrome. The ability to address these conditions/syndromes using interventional radiology procedures will likely enable patients to avoid having to undergo open surgery, which has numerous benefits. For example, a radiologist using an interventional radiology procedure has the ability to visualize internal anatomy of a patient without a large incision, which makes interventional radiology less invasive and less prone to risk of infection than an open surgery. Thus, interventional radiology enables procedures to be performed outside of a traditional hospital setting, significantly reducing the cost of diagnosis or treatment. Additionally, interventional radiology procedures have the potential to decrease the recovery time for a patient because of the less-invasive nature of the procedure.
Accordingly, there is a need for specifically designed medical instruments for performing interventional radiology procedures. There is also a need for new interventional radiology procedures to be developed that take advantage of the specifically designed medical instruments. In particular, there is a need for specifically designed medical instruments for performing interventional radiology procedures that focus on hands, wrists, feet, and ankles.
In one aspect, a medical instrument for cutting soft tissue during an interventional radiology procedure comprises a hypodermic needle having an inner needle surface, an outer needle surface, a proximal needle end, a distal needle end, and a needle axis. The inner needle surface defines a needle bore extending from the proximal needle end to the distal needle end. The distal needle end has a sharpened distal tip configured to puncture soft tissue. A stylet has a stylet body, a stylet head, an outer stylet surface, a proximal stylet end, a distal stylet end, and a stylet axis. The stylet axis is coaxial with the needle axis. The stylet head is located at the distal stylet end. At least a portion of the stylet is located within the needle bore. The portion of the stylet located within the needle bore and the inner needle surface of the hypodermic needle collectively form at least one fluid passageway. The stylet is movable relative to the hypodermic needle along the needle axis. The stylet is adjustable between a retracted configuration and a protracted configuration. The stylet head is located within the needle bore when the medical instrument is in the retracted configuration. The stylet head is located external to the needle bore when the medical instrument is in the protracted configuration. The fluid passageway enables fluid to flow from the proximal needle end to the distal needle end when the stylet is in the retracted configuration and in the protracted configuration. The fluid passageway is configured such that fluid in the fluid passageway flows between the outer stylet surface and the inner needle surface.
In another aspect, a method of performing an interventional radiology procedure on a patient exhibiting 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 through a wrist crease of the affected wrist down to a position immediately superficial of the transverse carpal ligament (TCL). Fluid is at least intermittently injected through the hypodermic needle while the hypodermic needle is being guided down to the position immediately superficial of the TCL. The hypodermic needle is pierced through the TCL while injecting fluid. 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 such that a distal end of the stylet extends from a 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 such that the stylet head is at least partially located within the fluid pocket. The TCL with the stylet head. The interventional radiology procedure is performed under continuous imaging that enables anatomic structures of the affected wrist to be visualized throughout the procedure.
In another aspect, a medical instrument for cutting soft tissue during an interventional radiology procedure comprises a hypodermic needle having a needle axis and a proximal and distal end. The needle comprises an inner needle surface defining a needle bore extending longitudinally along the needle axis from the proximal end to the distal end. The needle bore is configured such that fluid is passable through the needle bore. A stylet is slidably received in the needle bore. The stylet has a proximal and distal end. The stylet is slidable along the needle axis between a retracted position and a protracted position. The distal end of the stylet comprises a stylet head configured to manipulate soft tissue. The stylet head is sheathed by the hypodermic needle in the retracted position and protrudes from the distal end of the needle in the protracted position such that the stylet head is exposed. The medical instrument is configured to pass fluid through the needle bore along the stylet such that fluid is discharged from the distal end of the hypodermic needle.
A medical instrument in accordance with one or more aspects of the present disclosure can be used to conduct numerous interventional radiology procedures including, for example, a carpal tunnel release, a De Quervain release, a trigger finger release, a tarsal tunnel release, a plantar fascia release, a fasciotomy, a lavage (e.g., a shoulder lavage), and a tissue biopsy.
Other aspects will be in part apparent and in part pointed out hereinafter.
Reference is made in the following detailed description of preferred embodiments to accompanying drawings, which form a part hereof, wherein like numerals may designate like parts throughout that are corresponding and/or analogous. It will be appreciated that the figures have not necessarily been drawn to scale, such as for simplicity and/or clarity of illustration. For example, dimensions of some aspects may be exaggerated relative to others. Further, it is to be understood that other embodiments may be utilized. Furthermore, structural and/or other changes may be made without departing from claimed subject matter. References throughout this specification to “claimed subject matter” refer to subject matter intended to be covered by one or more claims, or any portion thereof, and are not necessarily intended to refer to a complete claim set, to a particular combination of claim sets (e.g., method claims, apparatus claims, etc.), or to a particular claim.
A medical instrument for use during an interventional radiology procedure in accordance with the present disclosure is generally indicated by reference number 10 in
The medical instrument 10 further includes a collar 16, a fluid fitting 18, a removable clip 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 fitting 18 to form a stylet subassembly 26. As discussed in more detail below, when the medical instrument 10 is assembled, the stylet 14 fits within the hypodermic needle 12 and the medical instrument 10 is adjustable between a retracted configuration in which the stylet is sheathed within the hypodermic needle (shown in
As seen in
In a preferred embodiment, the hypodermic needle 12 is configured to conform to a size defined by the Birmingham gauge. The Birmingham gauge is a system used to specify thickness and/or diameter of hypodermic needles. The Birmingham gauge is also known as the Birmingham wire gauge. The following table provides outer diameter, inner diameter, and nominal wall thickness for hypodermic needles defined by the Birmingham gauge. The inner diameters and nominal wall thicknesses of the various. gauges may vary from the dimensions shown below.
It is contemplated that in certain embodiments, a medical instrument in accordance with this disclosure can substantially conform to the dimensions of a gauge standard of any one of the Birmingham wire gauges listed in the chart above. A hypodermic needle can have an outer diameter in the range of outer diameters of the Birmingham gauge needles listed in the above chart and/or have an inner diameter in the range of the inner diameters of the Birmingham gauge needles listed in the above chart. Needles in the scope of this disclosure need not strictly conform to a Birmingham gauge standard in one or more embodiments. In one embodiment of the present disclosure, the outer and inner diameters of the hypodermic needle 12 are smaller than a 14-gauge needle and larger than a 28-gauge needle, as defined by the Birmingham gauge. In another embodiment, the outer and inner diameters of the hypodermic needle 12 are smaller than a 17-gauge needle and larger than a 23-gauge needle, as defined by the Birmingham gauge. In yet another embodiment, the outer and inner diameters of the hypodermic needle 12 is smaller than an 18-gauge needle and larger than a 22-gauge needle, as defined by the Birmingham gauge. The size of the hypodermic needle 12 will vary depending upon the type of interventional radiology procedure being performed and the purpose of the underlying interventional radiology procedure. For example, for interventional radiology procedures performed on hands, wrists, feet, and/or ankles, the hypodermic needle 12 will likely be a hypodermic needle smaller than a 17-gauge needle and larger than a 23-gauge needle, as defined by the Birmingham gauge. A hypodermic needle of this size enables a radiologist to perform an interventional radiology procedure within the space constraints surrounding hands, wrists, feet, and/or ankles. A person of ordinary skill in the art will understand that the hypodermic needle does not have to conform to a size defined by the Birmingham gauge.
As seen in
The stylet 14 is configured such that after medical instrument 10 is assembled, the medical instrument can pass fluid through the needle bore 38 along the outer stylet surface 46 of the stylet such that fluid is discharged from the distal needle end 34. The outer stylet surface 46 of the stylet 14 includes at least one longitudinal fluid-passing surface and at least one bearing surface. In the embodiment shown in
As seen in
The stylet head 44 is located at the distal stylet end 50 of the stylet 14. The medical instrument 10 can be used for various reasons within various types of interventional radiology procedures, depending on a number of factors (e.g., size of the hypodermic needle, type of fluid being imparted through the medical instrument, imaging method, etc.). One primary factor affecting how a radiologist will use the medical instrument 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 number of functions within a patient, including cutting and/or moving soft tissue. The various designs for the stylet head 44 are discussed in more detail below.
When the medical instrument 10 is assembled, which is shown
When the medical instrument 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 instrument to be adjusted from the retracted configuration (shown in
The hypodermic needle 12 is fixedly connected to the collar 16, as shown in
The stylet 14 is fixedly connected to a fluid fitting 18, as shown in
As seen in
Further, the proximal stylet end 48 is secured to the fluid fitting 18 such that fluid is passable through the interface between the proximal stylet end and the fluid fitting in one or more embodiments. For example, in the illustrated embodiment, the stylet region 88 is substantially circular in cross-section. Thus, although the stylet region 88 snugly receives the proximal stylet end 48 of the stylet 14, fluid channels 94 are formed between the fluid fitting 18 and the stylet because of the flats 54, as seen in
As seen in
Accordingly, the stylet 14, the fluid fitting 18, the seal 94, and the ferrule 96 are fixed relative to each other and collectively form the stylet subassembly 26.
As seen in
As seen in
As seen in
Fluid then flows along the stylet body 42 from the proximal needle end 32 to the distal needle end 34 through fluid passageways 56. Fluid originating from the interior volume of syringe 86 is ultimately discharged from the medical instrument 10 through the sharpened distal tip 40 of the hypodermic needle 12. Notably, fluid from the syringe 86 follows this general fluid path regardless of whether the medical instrument 10 is in the retracted configuration, the protracted configuration, or any intermediate configuration. Accordingly, during an interventional radiology procedure, fluid from the syringe 86 can be injected continuously or intermittently regardless of positioning of the stylet 14 within the hypodermic needle 12. As discussed in more detail below, the ability to inject fluid at any point during an interventional radiology procedure enables a radiologist to more readily identify the position and/or movement of soft tissue for certain imaging methods (e.g., ultrasound). Additionally, the ability to inject fluid at any point during an interventional radiology procedure enables a radiologist to hydrodissect soft tissue throughout the procedure, as discussed in more detail below.
The medical instrument 10 may further include a locking mechanism 22, which can be seen in
To release the locking mechanism 22, the radiologist pulls the pull tab 106 outwardly such that the distal locking ledge 104 no longer abuts the proximal collar end 62. This enables the distal locking ledge 104 to slide past the proximal collar end 62, thus enabling the stylet subassembly 26 to move relative to the needle subassembly 24. In this manner, the locking mechanism 22 can be released to enable the medical instrument 10 to adjust from the retracted configuration (shown in
A person of ordinary skill in the art will understand and appreciate that other types of locking mechanisms could be used for the medical instrument 10 that do not incorporate a pull tab. For example, the medical instrument 10 could be designed to incorporate a twist type locking mechanism. In such an embodiment, the removable clip 20 and the collar 16 could be keyed in a manner such that the removable clip (and therefore the stylet subassembly 26) cannot be moved axially relative to the needle subassembly 24 until rotating the removable clip and the stylet subassembly. Additional alternative locking mechanisms for the medical instrument 10 include, but are not limited to, collets, set screws, removable snap-in blocks and keys, and any manner of other devices. These locking mechanisms could be used to lock linear motion of the stylet subassembly 26 relative to needle assembly 24. In addition or alternatively, these locking mechanisms could be used to lock rotational movement of the stylet subassembly 26 about the stylet axis 52.
A person of ordinary skill in the art will further understand and appreciate that various components of the medical instrument 10 can be designed in a manner to provide an extracorporeal indicator to the radiologist of the orientation of the hypodermic needle 12 (e.g., bevel up or bevel down) and the orientation of the stylet 14. For example, as seen in
In general, one or both of the collar 16 and the fluid fitting 18 forms a handle that is gripped by the radiologist and manipulated by hand to control the medical instrument 10. In addition to the handle formed by the collar and/or fitting, a radiologist may grip and manipulate the instrument 10 using the syringe 86 (broadly, fluid source) that is coupled to the fluid fitting 18. When the components at the proximal end portion of the medical instrument 10 are considered to constitute a handle, it is apparent that the collar 16 generally forms a handle housing and the fluid fitting 18 generally forms a carriage having a portion that slidably received in the housing for movement along the needle axis with respect to the housing. Further, in the illustrated embodiment, the carriage (fluid fitting 18) is rotatably received in the housing (collar 16) for rotation with respect to the housing about the needle axis. It will be understood that other handle configurations can be used for the medical instrument. In general, in a suitable handle, one of the housing and the carriage can comprise a fluid coupling configured to couple the medical instrument to a fluid source, and together the housing and carriage can define passaging providing sealed fluid communication between the fitting and the needle bore. In exemplary embodiments of handles within the scope of this disclosure, the carriage (e.g., the fitting 18) is movable relative to the housing (e.g., the collar 16) through a range of motion comprising a proximal end position and a distal end position. Further, certain handles within the scope of this disclosure include one or more locking mechanisms configured to selectively and releasably lock the carriage at one or both of the proximal end position and the distal end position in the range of motion.
The medical instrument 10 can be used for a variety of reasons in various types of interventional radiology procedures, depending on a number of factors (e.g., size of the hypodermic needle, type of fluid being pushed through the medical instrument, imaging method, etc.). One factor is the type and/or design of the stylet head 44 of the stylet 14. As an example, with one type of a stylet head, the medical instrument 10 can be used to cut soft tissue for performing a carpal tunnel release guided by one type of an imaging method (e.g., ultrasound). With another type of a stylet head, the medical instrument 10 can be used to cut soft tissue for performing a De Quervain's tendon release guided by another type of an imaging method (e.g., MRI). Yet, with a third type of a stylet head, the medical instrument 10 can be used to move soft tissue to enable a prostate biopsy to be performed while using an imaging method. Accordingly, a person of ordinary skill in the art will understand that the medical instrument in accordance with the present disclosure is extremely versatile and capable of being used for multiple types of interventional radiology procedures.
The radiologist can cut soft tissue abutting the cutting edge 112 in a number of ways. For example, the radiologist can cut soft tissue using the cutting edge 112 by adjusting the medical instrument 10 from the retracted configuration to the protracted configuration or vice versa. For example, it is contemplated that tissue could be cut as the stylet is reciprocated along the needle between the retracted and protracted positions. Alternatively, the radiologist can cut soft tissue using the cutting edge 112 by placing and holding the stylet 14 in the protracted configuration and moving the entire medical instrument 10 (including the hypodermic needle 12 and the stylet) as a unit in a proximal/distal direction and/or a 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 to place the cutting edge 112 adjacent soft tissue desired to be cut. In one or more embodiments, the protracted stylet head 44a is used to cut tissue by urging the cutting edge 112 toward the tissue. When the cutting edge 112 is in contact with the tissue, the radiologist can urge the stylet head outward while sliding the longitudinal cutting edge along the tissue, thereby slicing through tissue with the cutting edge. A person of ordinary skill in the art will understand that the foregoing list of examples of how a radiologist can cut soft tissue using stylet head 44a is not exhaustive.
As discussed above, the medical instrument 10 can be used for various reasons within various types of interventional radiology procedures, depending on a number of factors (e.g., size of the hypodermic needle, type of fluid being pushed through the medical instrument, imaging method, etc.). One interventional radiology procedure for which the medical instrument 10 is particularly suited is ultrasound guided carpal tunnel release. The carpal tunnel CT is illustrated in
Carpal tunnel syndrome involves compression of a patient's median nerve MN deep in the wrist. Most commonly, the patient's median nerve MN is compressed by the transverse carpal ligament TCL (also referred to as the flexor retinaculum). The TCL attaches to the hook of hamate (labeled as element 2) and the trapezium (labeled as element 3). The TCL forms the roof of the carpal tunnel located on the volar aspect of the wrist. As seen in
Most often, a patient experiencing carpal tunnel syndrome is prescribed nonsurgical methods in an attempt to remediate the compression of the median nerve. These nonsurgical methods may include rest, splinting, physical therapy, and corticosteroid injections. If one or more of the aforementioned nonsurgical methods fails to remediate the compression of the median nerve MN, a release of the median nerve MN may be achieved by sectioning the TCL. Historically, the TCL has been sectioned using open surgery. Open carpal tunnel releases, however, have a number of drawbacks. For example, open surgery is invasive and requires a large incision (often times more than 60 mm in length). The large incision increases scarring, the risk of infection, and the risk of complication during the surgery. It also increases the recovery period for a patient. Additionally, an open carpal tunnel release must be performed in an operating room and requires multiple specialists to be present (e.g., orthopedic surgeon and an anesthesiologist). The necessity to perform an open carpal tunnel release in an operating room with multiple specialists present dramatically increases medical costs associated with the procedure.
Using the medical instrument 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 entirety of the carpal tunnel release procedure. Direct visualization enables the radiologist to guide the medical instrument 10 to the appropriate location within the patient without damaging any nerves and/or blood vessels. Although this disclosure describes certain exemplary methods of performing carpal tunnel release as being conducted by a radiologist, it is to be understood that other practitioners or medical health professionals could conduct one or more aspects of any of the methods described herein.
Direct visualization can be achieved through several different types of interventional imaging methods, including, for example, X-ray fluoroscopy, computed tomography (CT), ultrasound, and magnetic resonance imaging (MM). The imaging method discussed throughout the remaining portion of the detailed description will be ultrasound. A person of ordinary skill in the art will understand, however, that other suitable imaging methods could be used in accordance with the method disclosed herein.
At the beginning of the interventional radiology procedure, a patient experiencing symptoms of carpal tunnel syndrome is placed in a supine position or a recumbent position, depending upon the circumstances. For example, a radiologist may prefer to place the patient in either a supine position or a sitting position depending upon available room equipment (e.g., chair or bed) and room layout. The patient's affected wrist is oriented such that the palm correlating to the affected wrist is facing upwards (i.e., palmar), as illustrated in
After the radiologist visualizes the anatomical structures of the patient's affected wrist, a first hypodermic needle (referred to from hereon as the “numbing needle”) may be introduced through a wrist crease of the affected wrist. The wrist crease can be either the proximal wrist crease PWC or the distal wrist crease DWC, as illustrated in
After the patient is sufficiently anesthetized, the radiologist removes the numbing needle from the patient and introduces the medical instrument 10 into the patient with the stylet 14 in the retracted configuration. A syringe containing fluid is connected to the fluid fitting 18 of the medical instrument 10. A person of ordinary skill in the art will understand that the fluid may be saline because the patient has already been anesthetized. Alternatively, the fluid may be a numbing fluid containing, for example, a mixture of saline, lidocaine, and/or triamcinolone acetonide. The medical instrument 10 is used during the interventional radiology procedure to perform the carpal tunnel release. For this reason, the hypodermic needle 12 associated with the medical instrument 10 will likely be larger in size than the numbing needle. In a preferred embodiment of performing the carpal tunnel release using the method described herein, the numbing needle is a 23-gauge hypodermic needle or greater on the Birmingham gauge. For example, the numbing needle has an outer diameter of less than or equal to about 0.75 mm in one or more embodiments (e.g., less than or equal to about 0.70 mm, less than or equal to 0.65 mm). The hypodermic needle 12 associated with the medical instrument 10 has a gauge number on the Birmingham gauge of less than or equal to 21. For example, the hypodermic needle 12 associated with the medical instrument 10 has an outer diameter of at least about 0.75 mm in one or more embodiments (e.g., at least about 0.80 mm). Using a larger needle for the hypodermic needle 12 enables the radiologist to use a larger, more robust stylet 14 to perform the carpal tunnel release. Suitably, however, the hypodermic needle 12 associated with the medical instrument 10 is also sufficiently small in cross-sectional size to navigate the carpal tunnel anatomy under ultrasound guidance without inadvertently damaging, for example, nerves or blood vessels. In one or more embodiments, the hypodermic needle 12 associated with the medical instrument 10 has an outer diameter of 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 1.5 mm, less than or equal to about 1.4 mm). In one or more embodiments, the hypodermic needle 12 associated with the medical instrument 10 comprises one of a 16-gauge, 17-gauge, 18-gauge, 19-gauge, 20-gauge, 21-gauge, and 22-gauge needle on the Birmingham gauge or otherwise comprises a needle of comparable external cross-sectional size to any in this group or any subset of this group of Birmingham needles. A person of ordinary skill in the art will understand that the hypodermic needle 12 associated with the medical instrument 10 could be used to perform the anesthetization in lieu of the numbing needle.
The radiologist may introduce the hypodermic needle 12 associated with the medical instrument 10 through the same entry point used to introduce the numbing needle. As such, the hypodermic needle 12 associated with the medical instrument 10 is introduced through a wrist crease of the affected wrist in one or more embodiments. Similar to the numbing needle, the hypodermic needle 12 associated with the medical instrument 10 can be introduced into the patient generally in the proximal-to-distal direction (see
Under continuous ultrasonographic guidance, the hypodermic needle 12 associated with the medical instrument 10 is guided along the anesthetized track until the sharpened distal tip 40 is immediately superficial of the TCL. In an embodiment, as the radiologist is advancing the hypodermic needle 12 associated with the medical instrument 10 along the anesthetized track, fluid is at least intermittently injected through the needle bore 38. Intermittently injecting fluid helps the radiologist better identify the exact positioning of the hypodermic needle 12 associated with the medical instrument 10 relative to various anatomic structures within the patient's body. Depending upon the circumstances, the fluid could be, for example, saline. Alternatively, the fluid may be a numbing fluid containing, for example, a mixture of saline, lidocaine, and triamcinolone acetonide. Intermittently injecting fluid containing a local anesthetic provides the additional benefit of ensuring the patient remains numb throughout the procedure.
After positioning the hypodermic needle 12 such that the sharpened distal tip 40 is immediately superficial of the TCL, the radiologist subsequently advances the hypodermic needle in a deep direction while injecting fluid through the needle bore 38. This results in hydrodissection as the sharpened distal tip 40 pierces the TCL. The jet of fluid 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 against the median nerve) and provides a fluid pocket 1006 that isolates the median nerve, as shown in
The radiologist subsequently adjusts the medical instrument 10 from the retracted configuration to the protracted configuration such that the stylet head 44 is at least partially positioned within the fluid pocket. A person of ordinary skill in the art will understand that the radiologist may move the hypodermic needle 12 superficial after creating the fluid pocket but before adjusting the stylet 14 from the retracted configuration to the protracted configuration. Alternatively, a person of ordinary skill in the art will understand that the radiologist may adjust the stylet 14 from the retracted configuration to the protracted configuration without moving the hypodermic needle 12 superficially. It should be further understood that, depending on the circumstances, various types of stylet head designs may be used to perform the carpal tunnel release procedure. One type of stylet head design that can be used for cutting the TCL and releasing the median nerve is stylet head 44a shown in
Depending on the orientation of the stylet head 44a relative to the hypodermic needle 12, the stylet may need to be rotated about the stylet axis 52 to position the cutting edge 104 adjacent the TCL as the medical instrument 10 is adjusted from the retracted configuration to the protracted configuration. For example, the stylet 14 may be oriented within the hypodermic needle 12 such that as the medical instrument 10 is adjusted from the retracted configuration to the protracted configuration, the cutting edge 112 is not adjacent the TCL. Orienting the stylet 14 in this manner may help the radiologist ensure the TCL is not cut by the cutting edge 112 as the medical instrument 10 is adjusted from the retracted configuration to the protracted configuration. After the medical instrument 10 is adjusted to the protracted configuration, the radiologist may rotate the stylet 14 about the stylet axis 52 to position the cutting edge 112 immediately adjacent the TCL. The radiologist may then place the cutting edge 112 into contact with the TCL and move the cutting edge relative to the TCL, thereby cutting the TCL. It is to be understood the cutting edge 112 may be moved in a reciprocating motion while urging the cutting edge against the TCL. The reciprocating motion causes the cutting edge 112 of the stylet head 44a to wear against the TCL until the TCL is dissected. Alternatively, the radiologist may cut the TCL with the cutting edge 104 by adjusting the stylet 14 from the protracted configuration to the retracted configuration. Using the medical instrument 10 in this manner ensures that the stylet 14 is sheathed or housed within the hypodermic needle 12 after cutting the TCL and releasing the median nerve. Subsequent to releasing the median nerve and the stylet head 44a being housed within the hypodermic needle 10 (i.e., moved to the retracted position), the radiologist may withdraw the medical instrument 10 from the patient. Because the stylet head 44a is in the retracted position, the patient is protected when withdrawing the medical instrument 10.
Alternatively, the stylet head 44a may be oriented within the hypodermic needle 12 such that as the stylet 14 is adjusted from the retracted configuration to the protracted configuration, the cutting edge 112 is adjacent to, and in contact with, the TCL. Having the stylet 14 oriented in this manner may enable the radiologist to make a first cutting pass on the TCL as the medical instrument 10 is adjusted from the retracted configuration to the protracted configuration. The radiologist can then make a second cutting pass on the TCL using the cutting edge 112 as the medical instrument 10 is moved from the protracted configuration to the retracted configuration. The two passes may help ensure the TCL is fully dissected and the median nerve is released, while also ensuring the stylet head 44a is sheathed or housed within the hypodermic needle 12 after cutting the TCL and releasing the median nerve.
While dissecting the TCL, the radiologist may intermittently inject fluid through the medical instrument 10. Injection of fluid assists with the dissection because the jet of fluid expelled from the distal needle end 34 of the hypodermic needle 12 helps force severance of the TCL. In many instances, the TCL has thickened such that it is taut about the median nerve. Thus, the combination of the cutting edge 112 of the stylet 14 repeatedly wearing against the TCL and the jet of fluid expelled from the distal needle end 34 will provide enough force to sever the taut TCL and release the median nerve. Injection of fluid while dissecting the TCL also enables the radiologist to identify when the TCL has been dissected. After the TCL has been severed, fluid being expelled from the hypodermic needle 12 will cause the TCL to flutter. This fluttering of the TCL provides the radiologist visual indication via ultrasonic guidance that the TCL has been cut and the median nerve released.
The radiologist may then remove the syringe connected with the fluid fitting 18 and replace the syringe with a second syringe containing a steroid fluid. The steroid fluid could be, for example, a corticosteroid such as triamcinolone acetonide. The second syringe is connected to the fluid fitting 18 such that the fluid fitting (and therefore the hypodermic needle 12) is fluidly connected with the steroid fluid. The radiologist may then inject the steroid fluid into the patient at the localized area where the TCL was dissected. Because the affected wrist was not “opened” as is the case in open surgery, the steroid fluid can be readily absorbed by the soft tissue of the patient. Injection of the steroid fluid helps prevent or lessen the inflammatory response of the patient as a result of the dissected TCL. This hinders the potential development of post procedural fibrosis or scar formation. Directing the steroid fluid through the hypodermic needle 12 associated with the medical instrument 10, rather than a new hypodermic needle inserted into the patient, ensures the steroid fluid is directed to the localized area where the TCL was dissected. In some instances, scarring of the TCL can result in the reoccurrence of carpal tunnel syndrome. The radiologist may then remove the second syringe from the fluid fitting and replace the second syringe with another syringe containing a non-steroid fluid (e.g., flushing fluid such as lidocaine or saline). This syringe, which is fluidly connected with the fluid fitting, enables the radiologist to flush the procedure needle of any steroid fluid before bringing the hypodermic needle 12 superficially to the patient's skin. Bringing steroid fluid superficially to the patient's skin can, in some instances, result in skin irritation. After flushing the hypodermic needle 12, the radiologist may remove the medical instrument 10 from the patient and place a small bandage at the point of entry, if necessary.
Using the medical instrument 10 and the interventional radiology procedure described above to dissect the TCL provides for a minimally invasive carpal tunnel release. While multiple entry points may be used throughout the entirety of the procedure (e.g., numbing needle may have a different entry point than the hypodermic needle 12 associated with the medical instrument 10), access for dissecting the TCL (or for both moving the median nerve and dissecting the TCL) can be provided through one, and only one, entry point in the hand/wrist of the patient. Unlike open carpal tunnel release in which the entry point is an incision that is in some instances multiple centimeters or inches in length, or even certain less invasive carpal tunnel release procedures that use smaller incisions on the order of 4 mm or greater, the entry point for dissecting the TCL in the procedure described herein is only a hypodermic needle puncture. Thus, in one or more embodiments, the entry point (e.g., hypodermic needle puncture) for an instrument which dissects a TCL has a maximum transverse 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 transverse dimension of the entry point facilitates conducting a carpal tunnel release procedure in a minimally invasive manner. The minimally invasive nature helps reduce the risk of infection, enables the procedure to be performed during an office visit at an outpatient facility (which helps reduce medical costs), drastically minimizes recovery time necessary for the entry point to heal, and significantly reduces the risk of scarring (both on the skin surface and internally at the location where the TCL is dissected).
It is to be understood that other types of stylet head designs that can be used for performing a carpal tunnel release other than stylet head 44a. Depending on the stylet head 44 and the positioning of the cutting edge on said stylet head, a person of ordinary skill in the art will understand that the exact procedure for dissecting the TCL may differ from that provided above. For example, if stylet head 44c is being used to dissect the TCL, the stylet 14 could be used in a manner such that the TCL is positioned within the hook region 118, thereby enabling cutting edge 124 to dissect the TCL.
It will be apparent to a person skilled in the art that the medical instrument 10 is suitable for use in other types of image-guided radiology procedures that involve manipulating soft tissue. In general, during any image-guided radiology procedure, the radiologist at least intermittently views the target anatomy with a form of imaging such as ultrasound, Mill, or the like. In some embodiments, the radiologists uses a numbing needle to establish an anesthetized track before introducing the medical instrument 10. To introduce the medical instrument, the sharpened tip of the hypodermic needle 12 pierces the skin of the patient or otherwise enters the body of the patient through an appropriate entry point. Then the needle 12 is advanced under image guidance until the needle distal end is located at the target site. At any time while advancing the needle 12, fluid can be continuously or intermittently imparted through the needle along the stylet 14 such that is discharged from needle distal end to achieve any desired effect, e.g., hydro-dissection, therapeutic treatment of tissue, anesthetization, image enhancement or improved visualization. When imaging shows the needle distal end to be at the target site, a stylet 14 with the desired stylet head is advanced through the needle bore to the protracted configuration. Subsequently, the medical instrument 10 is moved as a unit or the stylet 14 is moved relative to the needle 12 to manipulate the target tissue under image guidance as required in the procedure. At any time while using the stylet head to manipulate tissue, fluid can be continuously or intermittently imparted through the needle along the stylet 14 such that is discharged from needle distal end to achieve a desired effect, e.g., hydro-dissection, therapeutic treatment of tissue, anesthetization, image enhancement or improved visualization. Syringes containing any desired fluid can be coupled to the fluid fitting 18 and imparted through the needle 12 during the procedure. When the procedure is complete, the needle can be withdrawn from the patient.
Because a needle puncture is the sole entry point used for the procedure, suturing is typically not required and patient recovery can involve minimal pain and discomfort. Unlike open surgery, including less invasive surgical procedures that use smaller incisions on the order of 4 mm or greater, the entry point used to conduct procedures with the medical instrument 10 is only a hypodermic needle puncture. Thus, in one or more embodiments, the entry point (e.g., hypodermic needle puncture) for conducting a interventional radiology procedure using the medical instrument 10 has a maximum transverse 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 transverse dimension of the entry point facilitates conducting the procedure in a minimally invasive manner. The minimally invasive nature helps reduce the risk of infection, enables the procedure to be performed during an office visit at an outpatient facility (which helps reduce medical costs), drastically minimizes recovery time necessary for the entry point to heal, and significantly reduces the risk of scarring (both on the skin surface and internally at the location where the TCL is dissected).
Among other interventional radiology procedures that can be performed using the medical instrument 10, it is expressly contemplated that the instrument is used in the general manner described above to conduct procedures comprising De Quervain release, trigger finger release, tarsal tunnel release, plantar fascia release, arm or leg fasciotomy, a lavage (e.g., shoulder lavage), and tissue biopsy (e.g., pancreatic biopsy). In view of the foregoing, basic methods of using the medical instrument 10 to conduct these and other procedures will be apparent to a person skilled in the art.
For example, to conduct a De Quervain release, the hypodermic needle 12 is introduced under image guidance into the hand or wrist toward the affected tendons running alongside the wrist near the thumb. When the distal end of the needle is at the target site, the stylet having the desired stylet head configuration is advanced to the protracted configuration and used to release the affected tendons (with or without the aid of hydro-dissection or other therapeutic or image-enhancing fluids imparted through the needle bore during the procedure).
To conduct a trigger finger release, the hypodermic needle 12 is introduced under image guidance into the hand toward the annular ligament. When the distal end of the needle is at the target site (e.g., deep of the annular ligament), the stylet having the desired stylet head configuration is advanced to the protracted configuration and used to release the affected tendons (with or without the aid of hydro-dissection or other therapeutic or image-enhancing fluids imparted through the needle bore during the procedure).
To conduct a tarsal tunnel release, the hypodermic needle 12 is introduced under image guidance into the foot or ankle toward the tarsal ligament. When the distal end of the needle is at the target site, the stylet having the desired stylet head configuration is advanced to the protracted configuration and used to release the affected tendons (with or without the aid of hydro-dissection or other therapeutic or image-enhancing fluids imparted through the needle bore during the procedure).
To conduct a plantar fasciitis release, the hypodermic needle 12 is introduced under image guidance into the foot or ankle toward the plantar fascia. When the distal end of the needle is at the target site, the stylet having the desired stylet head configuration is advanced to the protracted configuration and used to release the plantar fascia (with or without the aid of hydro-dissection or other therapeutic or image-enhancing fluids imparted through the needle bore during the procedure).
To conduct an arm or leg fasciotomy, the hypodermic needle 12 is introduced under image guidance into the arm or leg toward the respective fascia at a plurality of locations longitudinally spaced apart along the arm or leg. When the distal end of the needle is at each target site, the stylet having the desired stylet head configuration is advanced to the protracted configuration and used to release the fascia (with or without the aid of hydro-dissection or other therapeutic or image-enhancing fluids imparted through the needle bore during the procedure).
To conduct a shoulder lavage, the hypodermic needle 12 is introduced under image guidance into the arm or shoulder. (It will be appreciated that the needle is introduced into other body parts when other lavages are to be conducted). Using the medical instrument, the shoulder lavage can be conducted generally using conventional lavage techniques except that the stylet head is used to break calcific deposits in the shoulder. During the procedure flushing fluid (e.g., saline) passed through the needle along the stylet is used to flush the calcium from the joint area. Subsequently, a steroid is passed through the needle along stylet into the joint area (e.g., into the bursa).
During a biopsy, the hypodermic needle 12 is introduced under image guidance toward the part of the anatomy to be biopsied. When the distal end of the needle is at the target site, the stylet having the desired stylet head configuration is advanced to the protracted configuration and used to extract samples of the target tissue. In one or more embodiments, a tissue sample is retained on the stylet head, which is then retracted. The collected tissue sample is then safely sheathed within the needle until the medical instrument is withdrawn.
When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the 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.
In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
As various changes could be made in the above products and methods without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.
This application claims priority to U.S. Provisional Patent Application No. 62/857,063, filed Jun. 4, 2019, and entitled MEDICAL INSTRUMENT FOR INTERVENTIONAL RADIOLOGY PROCEDURE, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62857063 | Jun 2019 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US20/36159 | Jun 2020 | US |
| Child | 17455828 | US |
