Divisible tissue dissection device and needle assembly

Abstract

A tissue dissection device and method thereof, the tissue dissection device is connectable to a needle used to define a puncture path. The tissue dissection device includes a blade (170) that cuts the skin while inserting the device into the puncture path to enlarge the puncture path. The tissue dissection device may be configured to laterally separate from an elongated medical device (50) (e.g., a guidewire). The tissue dissection device may include a channel (131) for receiving the elongated medical device. The channel may be configured to (i) retain the elongated medical device within the channel in the absence of intentional manipulation by a clinician and (ii) facilitate lateral removal of the elongated medical device from the channel in response to intentional manipulation. A needle assembly includes a needle coupled to the tissue dissection device. The tissue dissection device may include a sheath (121) extending along a distal portion of the tissue dissection device.

Description

[Background technology]

[0001] Prior to placing a catheter into a patient's blood vessel, it is common to cut an incision in the patient's skin adjacent the puncture path at the insertion site using a dilator to dilate the surrounding tissue. Typically, cutting the patient's skin and dilating the tissue around the puncture path are performed separately. In practice, cutting is usually performed using a specialized skin knicker or a scalpel with a No. 11 blade. Dilating is usually performed using a dilator that is 2 French sizes (0.67 mm) larger than the catheter being placed. Attempts to integrate cutting the patient's skin and dilating the tissue around the puncture path have resulted in spring-loaded blades that are generally considered unsafe due to the lack of control the clinician has over the blade. What is needed is a tissue dissection device that safely integrates cutting the patient's skin at the insertion site and dilating the tissue around the puncture path at the insertion site. Such a device would reduce procedure time and errors, for example, when placing a catheter at the insertion site.

[0002] Disclosed herein are tissue dissection devices, assemblies and methods that address the above. Summary of the Invention

[0003] Disclosed herein is a tissue dissection device, according to some embodiments, comprising a body defining a distal end and a proximal end, the body including (i) a channel wall defining a channel extending along a length of the body, (ii) one or more protrusions extending laterally from the channel wall adjacent the proximal end, and (iii) a sheath portion extending proximally from the distal end, the sheath portion disposed along the channel. The device further includes a blade attached to the body along an intermediate portion of the body, the blade extending laterally from the channel wall such that a cutting edge of the blade is disposed opposite the channel. The channel is configured to receive an elongate medical device to selectively prevent or permit lateral removal of the elongate medical device from the channel. The cutting edge is disposed at an angle relative to the channel such that a distal portion of the cutting edge is disposed closer to the channel than a proximal portion of the cutting edge. In some embodiments, the device is slidably displaceable along the elongate medical device. In some embodiments, the sheath portion has a sheath length of about 1 cm to 2 cm.

[0004] The device is configured for insertion along a puncture path extending between a patient's skin surface and a blood vessel wall, in some embodiments, the one or more protrusions define an insertion stop for the device during insertion of the device along the puncture path, and in some embodiments, the insertion stop defines a cutting depth of the blade according to an angle of the blade.

[0005] In some embodiments, the blade includes a pointed tip at a distal end of the blade, the pointed tip being disposed between an outer surface of the channel wall and an inner surface of the channel wall, and further, in some embodiments, a proximal edge of the blade is encapsulated within at least one of the one or more protrusions.

[0006] The blade may be formed from stainless steel and the body may be formed from a thermoplastic material by an injection molding process, hi some embodiments, the blade is insert molded into the body such that the sharp tip is molded into the channel wall and the trailing edge is molded into at least one of the one or more protrusions.

[0007] In some embodiments, the sheath portion includes a taper such that the diameter of the sheath portion adjacent the distal end of the body is smaller than the diameter of the sheath portion adjacent the blade. In some embodiments, the channel is configured (i) to permit lateral separation of the device from the elongated medical device in response to intentional manipulation by a clinician, and (ii) to prevent lateral separation of the device from the elongated medical device in the absence of intentional manipulation by the clinician.

[0008] In some embodiments, the channel walls define a gap extending along the channel, the gap having a width less than a diameter of the elongated medical device, the channel walls are deflectable to allow the gap to widen in response to intentional manipulation, the intentional manipulation including laterally displacing the elongated medical device out of the channel and through the gap.

[0009] In some embodiments, the channel walls define a gap extending along the channel, the gap having a width less than a diameter of the elongated medical device. The channel walls further include one or more frangible connection members extending across the gap and a hinge extending along the channel opposite the gap, the hinge being disposed between the first channel wall and the second channel wall. The intentional manipulation includes (i) breaking the one or more frangible connection members, (ii) widening the gap by rotating the first channel wall relative to the second channel wall about the hinge, and (iii) laterally displacing the elongated medical device from the channel through the gap. In some embodiments, the hinge is a living hinge formed by an injection molding process.

[0010] In some embodiments, the channel wall includes a first longitudinal channel wall section and a second longitudinal channel wall section disposed laterally opposite the first longitudinal channel wall section. The channel wall further includes one or more frangible connection members attaching the first longitudinal channel wall section to the second longitudinal channel wall section. The intentional manipulation includes breaking the one or more frangible connection members to separate the first longitudinal channel wall section from the second longitudinal channel wall section.

[0011] In some embodiments, the elongate medical device is one of a needle or a guidewire. In some embodiments, the elongate medical device is a needle and the sheath portion has a sheath length sufficient for the entire length of the device to extend between the beveled portion of the needle tip and the needle hub. In some embodiments, the body includes a connection hub disposed at a proximal end of the device, the connection hub configured to couple to the needle hub. In some embodiments, the connection hub includes a luer taper configured to couple to a corresponding luer taper of the needle hub.

[0012] Also disclosed herein is a needle assembly including a needle configured to define a puncture path between a patient's skin surface and a patient's blood vessel. The needle assembly further includes any of the tissue incision device embodiments summarized above.

[0013] In some embodiments of the assembly, the connection hub of the device is coupled to the needle hub, and in further embodiments, the distal end of the device is positioned adjacent to the beveled portion of the needle.

[0014] Also disclosed herein is a method for establishing a vascular access pathway. According to some embodiments, the method includes inserting a needle into a patient from a skin surface to a vascular lumen to define a puncture pathway, the needle being coupled to a tissue incision device, the needle being disposed within a channel extending along a sheath portion of the tissue incision device. The method further includes (i) inserting the sheath portion of the tissue incision device into the puncture pathway, (ii) advancing the tissue incision device along the puncture pathway to cause a blade of the tissue incision device to incise the skin adjacent the puncture pathway to enlarge the puncture pathway, (iii) withdrawing the needle from the puncture pathway, and (iv) withdrawing the tissue incision device from the puncture pathway.

[0015] In some embodiments of the method, advancing the tissue incising device includes sliding the tissue incising device distally along the needle, hi some embodiments of the method, the tissue incising device is coupled to the needle to define a simultaneous movement of the tissue incising device and the needle.

[0016] In some embodiments, the method further comprises inserting the sheath portion into the vessel lumen.In some embodiments, the method further comprises inserting a guidewire through the puncture pathway into the vessel lumen.

[0017] In some embodiments of the method, inserting the guidewire occurs after withdrawing the needle.In some embodiments of the method, advancing the tissue dissecting device occurs after inserting the guidewire.In some embodiments of the method, advancing the tissue dissecting device occurs after withdrawing the needle.

[0018] In some embodiments of the method, advancing the tissue dissecting device includes sliding the tissue dissecting device distally along the guidewire, the guidewire being disposed with the channel.

[0019] In some embodiments, the method further includes laterally separating the tissue-cutting device from the guidewire. In some embodiments of the method, separating the tissue-cutting device from the guidewire includes displacing a first portion of the tissue-cutting device relative to a second portion of the tissue-cutting device to establish a gap along the channel, the gap having a width sufficient to allow lateral passage of the guidewire.

[0020] These and other features of the concepts provided herein will become more apparent to those of ordinary skill in the art in view of the accompanying drawings and the following description, which describe in more detail certain embodiments of such concepts. [Brief description of the drawings]

[0021] [Figure 1A] FIG. 2 illustrates a first embodiment of a tissue dissection device according to some embodiments. [Figure 1B] 1B illustrates the tissue dissection device of FIG. 1A being used on a patient, according to some embodiments. [Figure 1C] 1B is a rear view of the tissue incision device of FIG. 1A according to some embodiments. [Figure 1D] FIG. 1B is a bottom view of the tissue dissection device of FIG. 1A according to some embodiments. [Figure 2A] 1B is a rear view of the tissue cutting device of FIG. 1A with the rotational engagement mechanism positioned in a closed state, according to some embodiments. [Figure 2B] 1B is a rear view of the tissue incision device of FIG. 1A with the rotational engagement mechanism positioned in an open state, according to some embodiments. [Figure 3A] 1B is a rear view of the tissue incision device of FIG. 1A with the separation engagement mechanism positioned in a closed state, according to some embodiments. [Figure 3B] 1B is a rear view of the tissue incision device of FIG. 1A with a separation engagement mechanism disposed in an open state, according to some embodiments. [Figure 4A] FIG. 13 illustrates a second embodiment of a tissue dissection device, according to some embodiments. [Figure 4B] 4B illustrates the tissue dissection device of FIG. 4A being used on a patient, according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Before some specific embodiments are disclosed in more detail, it should be understood that the specific embodiments disclosed herein do not limit the scope of the concepts provided herein. It should also be understood that the specific embodiments disclosed herein can have features that can be easily separated from the specific embodiment and, optionally, combined with or substituted for features of any of the other numerous embodiments disclosed herein.

[0023] With regard to the terms used herein, it should also be understood that the terms are intended to describe certain embodiments, and that the terms do not limit the scope of the concepts provided herein. Ordinal numbers (e.g., first, second, third, etc.) are generally used to distinguish or identify different features or steps within a group of features or steps, and do not provide sequential or numerical limitations. For example, the "first", "second", and "third" features or steps do not necessarily have to appear in that order, and a particular embodiment including such features or steps is not necessarily limited to three features or steps. In addition, unless otherwise indicated, any of the aforementioned features or steps may further include one or more features or steps. Labels such as "left", "right", "upper", "lower", "front", "rear", etc. are used for convenience and do not imply, for example, a particular fixed position, orientation, or direction. Instead, such designations are used to reflect, for example, a relative position, orientation, or direction. The singular forms "one", "one", and "said" also include plural references unless the context clearly dictates otherwise.

[0024] With respect to "proximal," for example, a "proximal portion" or "proximal section" of a tissue-cutting device includes the portion or section of the tissue-cutting device intended to be near the clinician when the tissue-cutting device is used on a patient. Similarly, for example, a "proximal length" of a tissue-cutting device includes the length of the tissue-cutting device intended to be near the clinician when the tissue-cutting device is used on a patient. For example, a "proximal end" of a tissue-cutting device includes the end of the tissue-cutting device intended to be near the clinician when the tissue-cutting device is used on a patient. Although a proximal portion, section, or length of a tissue-cutting device can include the proximal end of the tissue-cutting device, a proximal portion, section, or length of a tissue-cutting device need not include the proximal end of the tissue-cutting device. That is, unless otherwise suggested by context, a proximal portion, section, or length of a tissue-cutting device is not a terminal portion or length of a tissue-cutting device.

[0025] With respect to "distal," for example, a "distal portion" or "distal section" of a tissue incision device disclosed herein includes a portion or section of the tissue incision device intended to be near or within a patient when the tissue incision device is used on a patient. Similarly, for example, a "distal length" of a tissue incision device includes a length of the tissue incision device intended to be near or within a patient when the tissue incision device is used on a patient. For example, a "distal end" of a tissue incision device includes an end of the tissue incision device intended to be near a clinician or within a patient when the tissue incision device is used on a patient. Although a distal portion, section, or length of a tissue incision device can include the distal end of the tissue incision device, a distal portion, section, or length of a tissue incision device need not include the distal end of the tissue incision device. That is, unless otherwise suggested by context, a distal portion, section, or length of a tissue incision device is not a terminal portion or length of a tissue incision device.

[0026] The phrases "connected," "coupled," and "in communication" refer to any form of interaction between two or more entities, including, but not limited to, mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be coupled to one another even if they are not in direct contact with one another. For example, two components may be coupled to one another through an intermediate component.

[0027] Any method disclosed herein includes one or more steps or acts of carrying out the described method. Steps and / or acts of the method may be interchanged with one another. In other words, the order and / or use of certain steps and / or acts may be changed unless a certain order of steps or acts is required for the proper operation of the embodiment. Furthermore, only subroutines or portions of the methods described herein may be separate methods within the scope of the present disclosure. In other words, some methods may include only some of the steps described in a more detailed method. In addition, all embodiments disclosed herein are combinable and / or interchangeable unless otherwise stated, except where such combination or interchange is contrary to the described enablement of any embodiment.

[0028] Throughout this specification, similar references are made, such as by use of the term "substantially." To each such reference, it is to be understood that in some embodiments, a value, feature, or characteristic may be specified without similarities. For example, when modifiers such as "about" and "substantially" are used, these terms include within their scope the modified word in the absence of the modifier. For example, when the term "substantially linear" is described with respect to a feature, it is to be understood that in further embodiments, the feature may be in a strictly linear configuration.

[0029] Throughout this specification, a reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, references to a recited term or variations thereof listed throughout this specification do not necessarily all refer to the same embodiment.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. 1A-1D show a first embodiment of a tissue dissection device 100. FIG. 1A is a perspective view of a tissue dissection device (device) 100 coupled to an elongated medical device 50 (e.g., a needle, a guidewire, or a stylet). FIG. 1B is a side view of the device 100 positioned along a puncture path 15 of a patient 10. The device 100 is generally configured to be inserted along a puncture path 15 of the patient 10 that extends between a skin surface 13 and a blood vessel wall 21 of the patient 10. The device 100 is also generally configured to enlarge the puncture path 15 by incising the skin 12 and / or fascia 14 surrounding the puncture path 15.

[0031] The device 100 generally includes a body 110 having an elongated shape defining a distal end 111 and a proximal end 112. The body 110 includes a channel 130 extending along the length of the body 110 from the distal end 111 and the proximal end 112, the channel 130 configured to receive the elongated medical device 50. The channel 130 is formed by channel walls 131. The channel 130 includes a gap 132 extending along the length of the channel 130. The channel 130 is generally configured to facilitate sliding of the device 100 along the length of the elongated medical device 50. The body 110 may be formed from a thermoplastic material by an injection molding process.

[0032] A tissue dissection blade 170 is coupled to the body 110 such that a cutting edge 171 extends laterally from the body 110 along the intermediate portion 125 of the body 110. The blade 170 is configured to generally incise or dissect the skin 12 and / or fascia 14 radially outward from the puncture path 15. The cutting edge 171 is disposed at an angle 173 relative to the channel 130 such that a distal portion of the cutting edge 171 is disposed closer to the channel 130 than a proximal portion of the cutting edge 171. Thus, the depth of such dissection by the blade 170 is generally defined by the insertion depth of the device 100. Although not shown, the body 110 may be tapered along the intermediate portion 125 such that the taper causes the widening of the puncture path 15 during advancement of the intermediate portion 125 with the blade 170.

[0033] Blade 170 may be formed from stainless steel. In some embodiments, blade 170 includes a pointed tip 172 at a distal end of blade 170, where pointed tip 172 is disposed between an outer surface of channel wall 131 and an inner surface of channel wall 131. In some embodiments, blade 170 is insert molded into body 110 such that pointed tip 172 is molded into channel wall 131.

[0034] The body 110 includes one or more protrusions 141 extending laterally from the channel wall 131 along a handle portion 140 of the body 110 adjacent the proximal end 112. The protrusions 141 may form a handle for the device 100, i.e., a clinician may grasp and manipulate the device 100 by the protrusions 141. In the illustrated embodiment, the body 110 includes two protrusions 141 extending in opposite directions from one another. However, in other embodiments, the body 110 may include one, three, four, or more protrusions 141. The protrusions 141 may take any suitable shape. For example, the protrusions 141 may form a rear wall as shown, where the rear wall is oriented substantially perpendicular to the body 110. In other embodiments, the protrusions 141 may form a longitudinal wall extending from the body 110 parallel to the body 110.

[0035] In some embodiments, protrusions 141, or a portion thereof, may define an insertion stop for device 100 during insertion of device 100 along puncture path 15, i.e., during insertion, a portion of protrusion 141 may abut skin surface 13 and prevent further insertion of device 100. In some embodiments, the insertion stop may define the cutting depth of blade 170 according to angle 173 of blade 170. In some embodiments, proximal edge 174 of blade 170 is enclosed within at least one of protrusions 141.

[0036] A sheath portion 121 of the body 110 is disposed along the distal portion 120 of the body 110. The sheath portion 121 is generally configured to be inserted through the puncture passage 15. A channel 130 extends along the sheath portion 121. In some embodiments, the sheath portion 121 includes a taper 122 adjacent the distal end 111 such that the diameter of the sheath portion 121 adjacent the distal end 111 is smaller than the diameter of the sheath portion 121 adjacent the blade 170. In some embodiments, the sheath portion 121 has a sheath length 123 of about 1 cm to 2 cm.

[0037] In some embodiments, the elongated medical device 50 may be a needle 150 configured to define a puncture path 15, which may be combined with the device 100 to define a needle assembly 105. More specifically, the needle assembly 105 includes the device 100 having a needle 150 disposed within the channel 130. In some embodiments, the device 100 may be positioned along the needle 150 such that the distal end 111 is disposed adjacent to the angled portion 157 of the needle 150.

[0038] 1C and 1D generally illustrate a first embodiment of an engagement mechanism configured to (i) prevent lateral separation of the device 100 from the elongated medical device 50 in the absence of intentional manipulation by a clinician, and (ii) permit lateral separation of the device 100 from the elongated medical device 50 in response to intentional manipulation by a clinician. FIG. 1C illustrates a rear view of the device 100 coupled to the elongated medical device 50, and FIG. 1D illustrates a bottom view of the device 100. With reference to FIGS. 1C and 1D, in the illustrated embodiment, the channel wall 131 defines a gap 132 extending along the channel 130. The gap 132 includes one or more portions having an interference gap width 133. The gap 132 may also include one or more portions having a clearance gap width 134. The interference gap width 133 is less than the diameter of the elongated medical device 50 and the clearance gap width 134 is greater than the diameter of the elongated medical device 50 .

[0039] The channel wall 131 includes one or more bendable portions 135 extending across the clearance gap width 134 to define an interference gap width 133. The bendable portions 135 are configured to retain the elongated medical device 50 within the channel 130 during use of the device 130. The bendable portions 135 are configured to bend outwardly toward the clearance gap width 134 to allow the elongated medical device 50 to be displaced laterally out of the channel 130 through the gap 132 when a clinician pulls or otherwise pushes the elongated medical device 50 out of the channel 130 (i.e., performs an intentional manipulation). In some embodiments, the bendable portions 135 may extend along the entire length of the device 100.

[0040] 2A and 2B show a second embodiment of an engagement mechanism that may be incorporated into device 100 to facilitate separation of device 100 from elongated medical device 50 by rotating first body portion 231A relative to second body portion 231B along hinge 236. First body portion 231A is rotatable relative to second body portion 231B between a closed state in which elongated medical device 50 is laterally restrained within channel 230 and an open state in which elongated medical device 50 is laterally removable from channel 230 through gap 232. Hinge 236 may be a living hinge formed by an injection molding process.

[0041] In some embodiments, one or more frangible connection members 237 may extend across the gap 232 between the first and second body portions 231A, 231B when the first and second body portions 231A, 231B are disposed in the closed position. The frangible connection members 237 prevent rotation of the first body portion 231A relative to the second body portion 231B, thereby preventing the elongated medical device 50 from being laterally removed from the channel 230 without intentional manipulation by the clinician. Intentional manipulation may include applying opposing rotational forces 217A, 217B to the protrusions 241A, 241B, respectively, to break the frangible connection members 237. The clinician may further rotate the first body portion 231A and the second body portion 231B relative to one another to sufficiently widen the gap 232 to facilitate lateral removal of the elongated medical device 50 from the channel 230 through the gap 232.

[0042] 3A and 3B show a third embodiment of an engagement mechanism that may be incorporated into the device 100 to facilitate separation of the device 100 from the elongated medical device 50 by separating the first channel wall section 331A from the channel wall section 331B along the gaps 332A, 332B. The first and second channel wall sections 331A, 331B are attached to one another by a number of frangible connecting members 337A, 337B that extend across the gaps 332A, 332B, respectively, to define a closed state of the channel 330. The channel 330 is transitioned to an open state by breaking the frangible connecting members 337A, 337B and separating the first and second channel wall sections 331A, 331B from one another.

[0043] The frangible connecting members 337A, 337B prevent separation of the first and second channel wall sections 331A, 331B, thereby preventing lateral removal of the elongated medical device 50 from the channel 332 without intentional manipulation by a clinician. Intentional manipulation may include applying opposing forces 317A, 317B to the protrusions 341A, 341B, respectively, to break the frangible connecting members 337A, 337B. The clinician may further separate the first and second channel wall sections 331A, 331B from one another to facilitate lateral removal of the elongated medical device 50 from the channel 330.

[0044] A method for establishing a vascular access pathway utilizing the tissue incision device 100 may include all or any subset of the following steps or processes, according to some embodiments. The method may be performed by a medical technician following a vascular access procedure. Methods for establishing a vascular access pathway are also disclosed herein. A clinician may insert a needle into a patient from a skin surface to a blood vessel lumen to define a puncture pathway, the needle coupled to a tissue incision device, the needle disposed within a sheath portion of the tissue incision device. The clinician may further insert the sheath portion of the tissue incision device into the puncture pathway. The clinician may further advance the tissue incision device along the puncture pathway to cause a blade of the tissue incision device to incise the skin adjacent the puncture pathway to enlarge the puncture pathway. After establishing and enlarging the puncture pathway, the clinician may withdraw the needle and tissue incision device from the puncture pathway.

[0045] Advancing the tissue dissecting device may include sliding the tissue dissecting device distally along the needle. The clinician may further insert a guidewire through the puncture pathway and into the vessel lumen. Inserting the guidewire through the puncture pathway may include inserting the guidewire through the needle.

[0046] In some embodiments, the clinician may laterally separate the tissue-cutting device from the guidewire, i.e., without unscrewing the tissue-cutting device from either end of the guidewire. In separating the tissue-cutting device from the guidewire, the clinician may displace a first portion of the tissue-cutting device relative to a second portion of the tissue-cutting device to establish a gap along the channel having a width sufficient to permit lateral passage of the guidewire. The clinician may also laterally separate the tissue-cutting device from the needle through the gap.

[0047] 4A and 4B show a second embodiment of a tissue dissection device that may be similar in some respects to the components of the tissue dissection device described in connection with FIGS. 1A-3B. It will be understood that all of the illustrated embodiments may have similar features. Accordingly, similar features are indicated with similar reference numbers. Accordingly, the relevant disclosure set forth above with respect to similarly identified features may not be repeated below. Furthermore, some features of the tissue dissection device and related components shown in FIGS. 1A-3B may not be indicated or identified by reference numbers in the drawings or specifically described in the following description. However, such features may be obviously the same or substantially the same as features shown in other embodiments and / or described with respect to such embodiments. Accordingly, the relevant description of such features applies equally to the features of the tissue dissection device of FIGS. 4A and 4B. Any suitable combination of features and variations thereof described with respect to the tissue dissection device and components shown in FIGS. 1A-3B may be used with the tissue dissection device and components of FIGS. 4A and 4B, and vice versa.

[0048] FIG 4A shows a side view of tissue dissection device (device) 400 coupled to a needle 450, and FIG 4B shows device 400 in use with a patient 50. Reference will now be made to FIG 4A and FIG 4B. Device 400 is generally configured for insertion along a puncture path 15 in patient 10 extending between a skin surface 13 and a blood vessel wall 21 of patient 10. Device 400 is further configured for advancement along a blood vessel 20 within a blood vessel lumen 22. Device 400 is also generally configured for enlarging puncture path 15 by incising skin 12 and / or fascia 14 surrounding puncture path 15.

[0049] The device 400 generally includes a body 410 having an elongate shape defining a distal end 411 and a proximal end 412. The body 410 includes a channel 430 extending along the length of the body 410 from the distal end 411 and the proximal end 412, the channel 430 being configured to receive a needle 450. The channel 430 is also configured to receive other elongate medical devices, such as a guidewire 480, as shown in FIG. 4B.

[0050] The channel 430 generally includes an engagement mechanism configured to prevent lateral separation of the device 400 from the needle 450 and / or guidewire 480 in the absence of intentional manipulation by the clinician, and to permit lateral separation of the device 400 from the elongated medical device 50 in response to intentional manipulation by the clinician. In some embodiments, the engagement mechanism may be similar in some respects to the mechanisms described above in connection with FIGS. 3A and 3B. More specifically, the body 410 may be splittable along the channel 430 in accordance with intentional manipulation by the clinician. The channel 430 generally is configured to facilitate sliding of the device 400 along the needle 450 and / or guidewire 480.

[0051] A tissue dissection blade 470 is coupled to the body 410 such that a cutting edge 471 extends laterally from the body 410 along the intermediate portion 425. The blade 470 is configured to generally incise or dissect the skin 12 and / or fascia 14 radially outward from the puncture path 15. The cutting edge 471 is disposed at an angle to the channel 430 such that a distal portion of the cutting edge 471 is disposed closer to the channel 430 than a proximal portion of the cutting edge 471. Thus, the depth of dissection by the blade 470 may be defined by the insertion depth of the device 400. The blade 470 may be formed from stainless steel. In some embodiments, the blade 470 includes a sharp tip 472 at a distal end of the blade 470, the sharp tip 472 may be disposed below an outer surface of the body 410. Although not shown, the body 410 may include a taper along the intermediate portion 425 such that the taper causes widening of the puncture path 15 during advancement of the intermediate portion 425 with the blade 470 .

[0052] The body 410 includes one or more protrusions 441 extending laterally from the body 410. The protrusions 441 may form a handle for the device 400, i.e., a clinician may grasp and manipulate the device 400 by the protrusions 441. In some embodiments, the protrusions 441, or a portion thereof, may define an insertion stop for the device 400 during insertion of the device 400 along the puncture path 15, i.e., during insertion, a portion of the protrusions 441 may abut the skin surface 13 and prevent further insertion of the device 400. In some embodiments, the insertion stop may define the cutting depth of the blades 470 according to the angle of the blades 470.

[0053] A sheath portion 421 of the body 410 is disposed along a distal portion of the body 410. The sheath portion 421 is generally configured for insertion into the blood vessel lumen 22 through the puncture path 15, as shown in FIG. 4B. In some embodiments, the sheath portion 421 includes a taper 422 adjacent the distal end 411. The sheath portion 421 may include flexibility to accommodate an angular difference between the puncture path 12 and the blood vessel 20. In other words, the sheath portion 421 may be configured to bend during use such that the sheath portion 421 may advance along the blood vessel lumen 422.

[0054] During use, needle 450 may be withdrawn from device 400 and guidewire 480 may be inserted through device 400 (i.e., channel 430). Device 400 may provide a guide for guidewire 480 while guidewire 480 is advanced along puncture path 15 into vascular lumen 22.

[0055] The device 400 further includes a connection hub 461 coupled to the body 410 at the proximal end 412. The connection hub 461 is generally configured to engage the needle hub 451 of the needle 450. More specifically, the connection hub 461 is configured to be selectively attached to the needle hub 451. In some embodiments, the connection hub 461 may resemble some features and functions of a female luer connector. Similarly, the needle hub 451 may resemble some features and functions of a corresponding male luer connector. In some embodiments, the connection hub 461 may include a female luer taper 462 for receiving and mating with the male luer taper 452 of the needle hub 451.

[0056] The length of the sheath portion 421 may correspond to the length of the needle 450 such that when the connection hub 461 is coupled to the needle hub 451, the distal end 411 of the device 400 (i.e., the distal end of the sheath portion 421) is disposed adjacent to the angled portion 457 of the needle 450. Because the connection hub 461 is coupled to the body 410, the connection hub 461 is also splittable along with the body 410 to allow lateral separation of the connection hub 461 from the needle 450 and / or the guidewire 480.

[0057] In some embodiments, the needle 450 may be combined with the device 400 to define a needle assembly 405. More specifically, the needle assembly 405 includes the device 400 having a needle 450 disposed within the channel 430. In some embodiments, the connection hub 451 may be coupled to the needle hub 461 such that the distal end 411 is disposed adjacent to the angled portion 457 of the needle 450.

[0058] A method for establishing a vascular access pathway utilizing the tissue incision device 400 may include all or any subset of the following steps or processes, according to some embodiments. The method may generally be performed by a medical technician following a vascular access procedure. Also disclosed herein is a method for establishing a vascular access pathway. A clinician may insert a needle into a patient from a skin surface to a vascular lumen to define a puncture pathway, the needle coupled to a tissue incision device, the needle disposed within a sheath portion of the tissue incision device. Further, the clinician may insert the sheath portion of the tissue incision device into the puncture pathway. The clinician may further advance the tissue incision device along the puncture pathway to cause a blade of the tissue incision device to incise the skin adjacent the puncture pathway to enlarge the puncture pathway. After establishing and enlarging the puncture pathway, the clinician may withdraw the needle and tissue incision device from the puncture pathway.

[0059] Advancing the tissue dissecting device may include sliding the tissue dissecting device distally over the needle. The clinician may further insert a sheath portion into the vessel lumen. The clinician may further insert a guidewire through the puncture pathway into the vessel lumen. The clinician may insert the guidewire after withdrawing the needle. The clinician may advance the tissue dissecting device after inserting the guidewire. The clinician may advance the tissue dissecting device after withdrawing the needle. Advancing the tissue dissecting device may include sliding the tissue dissecting device distally along the guidewire, the guidewire disposed with the channel.

[0060] During needle insertion, a tissue-cutting device can be coupled to the needle to define simultaneous movement of the tissue-cutting device and the needle such that insertion of the sheath portion and insertion of the needle occur simultaneously.

[0061] In some embodiments, the clinician may separate the tissue-cutting device from the guidewire laterally, i.e., without unscrewing the tissue-cutting device from either end of the guidewire. In separating the tissue-cutting device from the guidewire, the clinician may displace a first portion of the tissue-cutting device relative to a second portion of the tissue-cutting device to establish a gap along the channel having a width sufficient to allow lateral passage of the guidewire.

[0062] Although some specific embodiments are disclosed herein and the specific embodiments are disclosed in some detail, the specific embodiments are not intended to limit the scope of the concepts provided herein. Further adaptations or modifications may become apparent to those skilled in the art, and the broader aspects of the invention encompass these adaptations or modifications as well. Thus, departures from the specific embodiments disclosed herein may be made without departing from the scope of the concepts provided herein.

Claims

1. 1. A tissue dissection device comprising: a body defining a distal end and a proximal end, the body comprising: a channel wall defining a channel extending along the length of the body; one or more protrusions extending laterally from the channel wall adjacent the proximal end; a body including a sheath portion extending proximally from the distal end, the sheath portion disposed along the channel; a blade attached to the body along an intermediate portion of the body, the blade extending laterally from the channel wall such that a cutting edge of the blade is positioned opposite the channel; and Equipped with the channel is configured to receive an elongated medical device to (i) prevent lateral removal of the elongated medical device from the channel, and (ii) selectively allow lateral removal of the elongated medical device from the channel; A tissue cutting device wherein the cutting edge is positioned at an angle relative to the channel such that a distal portion of the cutting edge is positioned closer to the channel than a proximal portion of the cutting edge.

2. The device of claim 1 , wherein the device is slidably displaceable along the elongate medical device.

3. The device of claim 1 , wherein the device is configured for insertion along a puncture path extending between a patient's skin surface and a blood vessel wall.

4. The device of claim 3 , wherein the one or more protrusions provide an insertion stop for the device during insertion of the device along the puncture path.

5. The device of claim 4 , wherein the insertion stop defines a cutting depth of the blade according to the angle of the blade.

6. 10. The device of claim 1, the blade includes a sharp tip at a distal end of the blade; The device, wherein the pointed tip is disposed between an outer surface of the channel wall and an inner surface of the channel wall.

7. The device of claim 1 , wherein the proximal edge of the blade is encapsulated in at least one of the one or more protrusions.

8. The device of claim 1 , wherein the blade is formed from stainless steel.

9. 10. The device of claim 1, the body is formed from a thermoplastic material by an injection molding process; the blade is insert molded into the body such that the pointed tip is molded into the channel wall and the trailing edge is molded into the rear wall.

10. The device of claim 1 , wherein the sheath portion includes a taper such that the diameter of the sheath portion adjacent the distal end of the body is smaller than the diameter of the sheath portion adjacent the blade.

11. 10. The device of claim 1, wherein the channel comprises: configured to permit lateral separation of the device from the elongated medical device in response to intentional manipulation by a clinician; and A device configured to inhibit lateral separation of the device from the elongate medical device in the absence of intentional manipulation by the clinician.

12. 12. The device of claim 11, the channel walls define a gap extending along the channel, the gap having a width less than a diameter of the elongated medical device; the channel walls are deflectable to allow the gap to widen in response to the intentional manipulation; The device, wherein the intentional manipulation includes laterally displacing the elongate medical device from the channel through the gap.

13. 12. The device of claim 11, the channel walls define a gap extending along the channel, the gap having a width less than a diameter of the elongated medical device, the channel walls defining one or more frangible connection members extending across the gap; the channel wall further includes a hinge extending along the channel opposite the gap, the hinge being disposed between the first channel wall and the second channel wall; The intentional operation is breaking the one or more frangible connection members; widening the gap by rotating the first channel wall relative to the second channel wall about the hinge; laterally displacing the elongate medical device from the channel through the gap; Including, the device.

14. 14. The device of claim 13, wherein the hinge is a living hinge formed by an injection molding process.

15. 12. The device of claim 11, The channel walls are a first longitudinal channel wall section; and a second longitudinal channel wall section disposed laterally opposite the first longitudinal channel wall section; one or more frangible connection members attaching the first longitudinal channel wall section to the second longitudinal channel wall section; The intentional operation is breaking the one or more frangible connection members; separating the first longitudinal channel wall section from the second longitudinal channel wall section; Including, the device.

16. The device of claim 1 , wherein the sheath portion defines a length of about 1 cm to 2 cm.

17. The device of claim 1 , wherein the elongated medical device is one of a needle or a guidewire.

18. 10. The device of claim 1, the elongated medical device is a needle; The device wherein the sheath portion has a sheath length sufficient so that the entire length of the device extends between the beveled portion of the needle tip and the needle hub.

19. The device of claim 18 , wherein the body includes a connection hub disposed at the proximal end of the device, the connection hub configured to couple to the needle hub.

20. 20. The device of claim 19, wherein the connection hub includes a luer taper configured to mate with a corresponding luer taper of the needle hub.

21. 1. A needle assembly comprising: a needle configured to define a puncture path between a skin surface of a patient and a blood vessel of the patient; 21. The tissue incision device according to any one of claims 1 to 20, arranged to cover the shaft of the needle; A needle assembly comprising:

22. The needle assembly of claim 21 , wherein the connection hub of the device is coupled to the needle hub.

23. The needle assembly of claim 22, wherein the distal end of the device is positioned adjacent to a beveled portion of the needle.

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