Separable tissue dissection devices, assemblies and methods

Abstract

A tissue dissection device and method thereof, the tissue cutting device being coupleable to a catheter. The tissue dissection device includes a blade that cuts the skin during insertion of the device into the puncture tract to enlarge the puncture tract. The tissue dissection device is configured to be laterally separated from the catheter and / or guidewire. The tissue dissection device includes a channel for receiving the catheter and / or guidewire. The channel may be configured to (i) retain the catheter / guidewire within the channel in the absence of intentional action by the clinician, and (ii) facilitate lateral removal of the catheter / guidewire from the channel in response to an intentional action. The catheter assembly includes a catheter coupled with the tissue dissection device. The tissue dissection device may include a sheath extending along a distal portion of the tissue dissection device.

Description

[Background technology]

[0001] Before placing a catheter in a patient's blood vessel, it is common to incise the patient's skin around the puncture tract at the insertion site in order to dilate the tissue around the puncture tract with a dilator. Typically, incising the patient's skin and dilating the tissue around the puncture tract are performed separately. In practice, the incision is usually performed with a dedicated skin dissector or scalpel with a #11 blade. The dilation is usually performed with a dilator that is 0.7 mm (2 French sizes) larger than the catheter to be placed. Summary of the Invention [Problem to be solved by the invention]

[0002] Attempts to integrate incising the patient's skin and dilating the tissue around the puncture tract have resulted in spring-loaded blades that are generally considered unsafe because the clinician cannot control the blade. What is needed is a tissue dissection device that safely integrates incising the patient's skin at the insertion site with dilating the tissue around the puncture tract at the insertion site. Such a device would reduce procedure time and errors, for example, when placing a catheter at the insertion site.

[0003] Disclosed herein are tissue dissection devices, assemblies, and methods that address the above. [Means for solving the problem]

[0004] A tissue dissection device disclosed herein, according to some embodiments, includes a body defining a distal end and a proximal end, the body including a channel extending longitudinally along the body between the distal and proximal ends, the channel configured to receive a vascular catheter therein. A tissue dissection blade is attached to the body, the blade extending distally from the distal end and extending laterally from the longitudinal axis such that a cutting edge of the blade is disposed opposite the longitudinal axis of the channel.

[0005] In some embodiments, the device is configured to be inserted along a puncture tract extending between a patient's skin surface and a blood vessel wall, and the blade is configured to cut the patient's skin and dilate the puncture tract during insertion of the device.

[0006] In some embodiments, the distal end of the body provides an insertion stop for the device during insertion of the device. The cutting edge of the blade may be disposed at an angle relative to the longitudinal axis of the channel such that the distal portion of the cutting edge is closer to the longitudinal axis of the channel than the proximal portion of the cutting edge. In some embodiments, the insertion stop defines the depth of the incision of the blade according to the angle of the cutting edge.

[0007] The body may include one or more protrusions extending laterally from the body, hi some embodiments, the protrusions define a handle for the device. The blades 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 blades are insert molded into the body.

[0008] In some embodiments, the body includes a distal end and a sheath extending distally from the body, (i) the sheath extends along the blade, (ii) the channel extends along the sheath, and (iii) the sharp distal tip of the blade is insert molded into a wall of the sheath. In some embodiments, the sheath includes a taper such that insertion of the sheath into the puncture tract widens the puncture tract.

[0009] The device may be configured to (i) allow lateral separation of the device from the catheter in response to intentional action by a clinician, and (ii) prevent lateral separation of the device from the catheter in the absence of intentional action by the clinician.

[0010] In some embodiments, the body includes a first body side coupled to a second body side via a longitudinally oriented hinge, and the channel is disposed between the first body side and the second body side. In some embodiments, the channel is transitioned between a closed state and an open state by rotating the second body side relative to the first body side, and the catheter is laterally constrained within the channel in the closed state and the catheter is laterally removable from the channel in the open state. In some embodiments, the hinge is a living hinge formed by an injection molding process.

[0011] In some embodiments, a first of the one or more protrusions extends from a first body side and a second of the one or more protrusions extends from a second body side, and applying a compressive force to the first and second protrusions transitions the channel from a closed state to an open state.

[0012] In some embodiments, the body includes one or more frangible connecting members extending between the first and second body sides opposite the hinge, the one or more frangible connecting members restraining the channel closed and application of a compressive force causes the one or more frangible connecting members to break.

[0013] In some embodiments, the device further includes a blade cover selectively transitionable between a safe state and a use state, the blade cover (i) extending over the cutting edge in the safe state and (ii) positioned away from the cutting edge in the use state. In some embodiments, the blade cover is rotatably coupled to the body, and transitioning from the safe state to the use state includes rotating the blade cover. In some embodiments, rotation of the blade cover away from the safe state is prevented by a detent.

[0014] Also disclosed herein is a catheter assembly including a catheter configured for advancement along a patient's vasculature, and a tissue dissection device according to any of the embodiments summarized above coupled to the catheter.

[0015] In some embodiments, the tissue dissection device is attached to the catheter adjacent a diameter transition section of the catheter, hi some embodiments, the tissue dissection device is attached to the catheter adjacent a distal end of the catheter.

[0016] In some embodiments, during use, manipulation of the catheter is assisted by grasping the tissue dissection device. Also disclosed herein is a method for placing a catheter within a patient's vascular system, comprising: (i) inserting a needle into a patient from a skin surface to a blood vessel lumen to define a puncture path; (ii) inserting a guidewire through the puncture path into the patient's vascular system; (iii) advancing a catheter along the guidewire, the catheter including a catheter tube having a tissue cutting device as described above attached thereto; (iv) inserting the tissue cutting device into the puncture path such that a blade of the tissue cutting device cuts the skin adjacent the puncture path to enlarge the puncture path; (v) laterally separating the tissue cutting device from the catheter tube; and (vi) advancing the catheter along the vascular system.

[0017] In some embodiments of the method, the tissue dissection device includes a body defining a distal end and a proximal end. The body includes a channel extending between the distal end and the proximal end. The catheter tube is disposed within the channel.

[0018] In some embodiments of the method, the blade extends distally from the distal end of the body of the tissue cutting device such that, during use, the blade extends along the guidewire, causing the blade to extend distally along the longitudinal axis of the channel, with the cutting edge of the blade positioned on the opposite side of the longitudinal axis.

[0019] In some embodiments of the method, the cutting edge is positioned at an angle relative to the guidewire such that the depth of the incision is defined by the depth of insertion of the device within the puncture tract. In some embodiments, the distal end of the body defines an insertion stop for the tissue-cutting device. Inserting the tissue-cutting device into the puncture tract includes abutting the insertion stop against the patient's skin surface.

[0020] In some embodiments of the method, the device includes a sheath coupled to the body, the sheath extending distally from a distal end of the body. The channel extends along the sheath. In some embodiments of the method, the sharp distal tip of the blade is disposed within a wall of the sheath.

[0021] In some embodiments of the method, the sheath includes a taper configured to dilate the puncture tract during insertion of the sheath into the puncture tract. In some embodiments of the method, the device includes a blade cover selectively transitionable between a safe state and a use state, the blade cover extending over the cutting edge in the safe state and positioned away from the cutting edge in the use state, the method further includes transitioning the blade cover from the safe state to the use state, in some embodiments of the method, the blade cover is rotatably coupled to the body, and transitioning the blade cover from the safe state to the use state includes rotating the blade cover away from the cutting edge.

[0022] In some embodiments of the method, the body includes a first body side coupled to a second body side via a longitudinally oriented hinge, and the channel is disposed between the first body side and the second body side. According to such embodiments, the channel is transitioned between a closed state and an open state by rotating the second body side relative to the first body side. The catheter is laterally constrained within the channel in the closed state and laterally removable from the channel in the open state.

[0023] In some embodiments of the method, the first body side includes a first lateral protrusion and the second body side includes a second lateral protrusion, and the method further includes transitioning the channel from a closed state to an open state by applying a compressive force to the first and second protrusions.

[0024] In some embodiments, the method may further include laterally removing the guidewire from the channel in the open state. These and other features of the concepts provided herein will become more apparent to those of ordinary skill in the art upon consideration of the accompanying drawings and the following description, which describe in more detail certain embodiments of such concepts. [Brief description of the drawings]

[0025] [Figure 1A] 1 illustrates a tissue dissection device coupled with a catheter, according to some embodiments. [Figure 1B] 1B illustrates the tissue dissection device of FIG. 1A in use on a patient, according to some embodiments. [Figure 2A] FIG. 1B is a side view of the tissue incision device of FIG. 1A according to some embodiments. [Figure 2B] FIG. 1B is a rear view of the tissue incision device of FIG. 1A positioned in a closed state, according to some embodiments. [Figure 2C] FIG. 1B is a rear view of the tissue incision device of FIG. 1A positioned in an open state, according to some embodiments. [Figure 3A] 1B illustrates the tissue cutting device of FIG. 1A including an optional blade cover placed in a safe position, according to some embodiments. [Figure 3B] 3B illustrates the tissue cutting device of FIG. 1A with the blade cover of FIG. 3A positioned in use, according to some embodiments. [Figure 4] 1B illustrates the tissue dissection device of FIG. 1A including an optional sheath extending distally from the body of the tissue dissection device, according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Before disclosing some specific embodiments in more detail, it should be understood that the specific embodiments disclosed herein are not intended to limit the scope of the concepts provided herein. It should also be understood that a specific embodiment disclosed herein may have features that are easily separable from the specific embodiment and that may be combined or substituted in any way with features of any of the numerous other embodiments disclosed herein.

[0027] With regard to the terms used herein, it should also be understood that these terms are intended to describe certain embodiments and are not intended to 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, any of the aforementioned features or steps may similarly include one or more further features or steps unless otherwise indicated. Designations such as "left", "right", "up", "down", "front", "rear", etc. are used for convenience and do not imply, for example, a specific fixed position, orientation, or direction. Instead, such designations are used to reflect, for example, a relative position, orientation, or direction. The singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

[0028] With respect to "proximal," for example, a "proximal portion" or "proximal section" of a tissue-cutting device includes the portion of the tissue-cutting device that is intended to be near the clinician when used on a patient. Similarly, for example, a "proximal length" of a tissue-cutting device includes the length of the tissue-cutting device that is intended to be near the clinician when used on a patient. For example, a "proximal end" of a tissue-cutting device includes the end of the tissue-cutting device that is intended to be near the clinician when used on a patient. A proximal portion, section, or length of a tissue-cutting device may include the proximal end of the tissue-cutting device. However, 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 the context suggests otherwise, a proximal portion, section, or length of a tissue-cutting device is not a tissue-cutting device terminal portion or length.

[0029] With respect to "distal," for example, a "distal portion" or "distal section" of a tissue incision device includes a portion of the tissue incision device that is 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 that is 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 that is intended to be near or within a patient when the tissue incision device is used on a patient. A distal portion, section, or length of a tissue incision device may include the distal end of the tissue incision device. However, 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 the context suggests otherwise, a distal portion, section, or length of a tissue-cutting device is not the terminal portion or length of the tissue-cutting device.

[0030] The phrases "connected to," "coupled to," and "in communication with" refer to any form of interaction between two or more elements, including but not limited to mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be connected 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.

[0031] Any method disclosed herein includes one or more steps or actions for carrying out the method described. The steps and / or actions of the method may be interchanged with one another. In other words, the order and / or use of certain steps and / or actions may be modified unless a specific order of steps or actions is required to properly implement 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, or such combination or interchange would be contrary to the described enablement of any embodiment.

[0032] 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, the value, feature, or characteristic may be specified without the similar. 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.

[0033] 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, the recited phrases or variations thereof listed throughout this specification do not necessarily all refer to the same embodiment.

[0034] 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 and 1B show a tissue dissection device 100. FIG. 1A is a perspective view of the tissue dissection device (device) 100 coupled to a catheter 50 (e.g., a central venous catheter) having a guidewire 60 threaded through the lumen of the catheter 50. The device 100 is generally configured to expand a puncture tract to accommodate insertion of the catheter 50 through the skin and into the vascular system of a patient. The device 100 generally includes a body 110 defining a distal end 111 and a proximal end 112. The device 100 may be coupled to the catheter 50 to define a catheter assembly 150. In some embodiments, the device 100 may be attached to the catheter 50 at a distal end of the catheter tube 51 of the catheter 50. In other embodiments of the catheter assembly 105, the device 100 may be attached at another location along the catheter tube 51, for example, at a tapered transition section of the catheter tube 51. The diameter of the catheter tube 51 is larger proximal to the transition section.

[0035] 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 being configured to receive the catheter tube 51 therein. The channel 130 defines a longitudinal axis 130A. The body 110 may be formed from a thermoplastic material by an injection molding process.

[0036] The device 100 is generally configured to (i) prevent lateral separation of the device 100 from the catheter 50 and / or guidewire 60 in the absence of intentional action by the clinician, and (ii) enable lateral separation of the device 100 from the catheter 50 and / or guidewire 60 in response to an intentional action by the clinician. More specifically, the body 110 is configured to laterally constrain the catheter tube 51 and / or guidewire 60 within the channel 130 unless an intentional action is taken by the clinician to enable lateral removal of the catheter tube 51 and / or guidewire 60 from the channel 130. The channel 130 can enable longitudinal displacement of the catheter tube 51 and / or guidewire 60 within the channel 130, including longitudinal removal of the catheter tube 51 and / or guidewire 60 from the channel 130. The body 110 is also configured to split along the length of the channel 130 in response to an intentional action to allow the catheter tube 51 and / or guidewire 60 to be removed laterally from the channel 130, as described further below.

[0037] A tissue dissection blade 170 having a cutting edge 171 is coupled to the body 110 such that the blade 170 extends distally from the distal end 111 and such that the cutting edge 171 is disposed opposite the longitudinal axis 130A. The blade 170 is generally configured to incise or cut the skin and / or fascia in a radially outward direction from the puncture tract 15. The cutting edge 171 is disposed at an angle 273 (see FIG. 2A ) relative to the longitudinal axis 130A such that a distal portion of the cutting edge 171 is disposed closer to the longitudinal axis 130A than a proximal portion of the cutting edge 171. Thus, the depth of the incision by the blade 170 is generally defined by the depth to which the device 100 is inserted. The blade 170 may be formed from stainless steel. In some embodiments, the blade 170 includes a sharp tip 172 at the distal end of the blade 170.

[0038] The body 110 includes one or more protrusions 141 extending laterally from the body 110. The protrusions 141 may form a handle for the device 100, i.e., a clinician may grasp and manipulate the device 100 and / or catheter 50 via the protrusions 141. In the illustrated embodiment, the body 110 includes two protrusions 141. However, in other embodiments, the body 110 may include one, three, four, or more protrusions 141. The protrusions 141 may be formed in any suitable shape to aid in grasping and / or manipulating the device 100.

[0039] FIG. 1B is a side view of the device 100 positioned along the puncture tract 15 of the patient 10. The catheter tube 51 is attached to the device 100 at a distal end of the catheter tube 51. The guidewire 60 is threaded through the catheter tube 51. The guidewire 60 is further threaded through a channel 130 of the device 100 and through the puncture tract 15 into the blood vessel 20. As shown, the device 100 is generally configured to be inserted into the puncture tract 15 of the patient 10, which extends between the skin surface 13 and the blood vessel wall 21 of the patient 10. The device 100 is also generally configured to dilate the puncture tract 15 by incising the skin 12 and / or fascia 14 surrounding the puncture tract 15. In some use cases, during insertion of the device 100 into the puncture tract 15, the device 100 is displaced along the guidewire 60, which provides a guide for the device 100.

[0040] In some embodiments, the body 110, or a portion thereof, may define an insertion stop for the device 100 during insertion of the device 100 into the puncture tract 15. That is, during insertion, a portion of the body 110 may abut the skin surface 13 to prevent further insertion of the device 100. In some embodiments, the insertion stop may define the cutting depth of the blade 170 according to the angle 273 of the cutting edge 171.

[0041] 2A shows a side view of the device 100. The body 110 is cut away to show the catheter tube 51 disposed within the channel 130. The guidewire 60 is also shown extending through the catheter tube 51 and the channel 130. As mentioned above, the channel 130 is configured (i.e., sized and shaped) to receive the distal end of the catheter tube 51 therein, which may include a taper. In some embodiments, the channel 130 may be configured to correspond to the shape of the distal end of the catheter tube 51. Thus, the channel 130 may include a larger diameter portion 231 that extends inside the proximal end 112 of the body 110.

[0042] The channel 130 is also configured to receive the guidewire 60 therethrough. In some embodiments, the channel 130 may include a reduced diameter section 232 that matches the diameter of the guidewire 60. In other words, the reduced diameter section 232 may slidably receive the guidewire 60 while constraining the lateral position of the guidewire 60. More specifically, the reduced diameter section 232 may constrain the lateral position of the guidewire 60 directly adjacent the bottom edge 274 and / or the sharp end 172 of the blade 170. By constraining the sharp end 172 directly adjacent the guidewire 60 during use, the tendency of skin or facial tissue to displace between the blade 170 and the guidewire 60 is minimized. That is, the tendency of skin bridging is minimized. In other embodiments, the reduced diameter section 232 may be omitted. In such embodiments, the lateral position of the guidewire 60 may be constrained by the catheter tube 51.

[0043] In some embodiments, the catheter tube 51 may be bonded to the body 110 via an adhesive 210 (e.g., a pressure sensitive adhesive) to prevent longitudinal displacement of the catheter tube 51 within the channel 130 in the absence of intentional action by the clinician. The bond may be configured to allow separation of the body 100 from the catheter tube 51 in response to an intentional action.

[0044] The blade 170 is molded and positioned such that the cutting edge 171 of the blade 170 is disposed at an angle 273 relative to the longitudinal axis 130A of the channel 130. The angle 273 is defined such that a distal portion of the cutting edge 171 is closer to the longitudinal axis 130A than a proximal portion of the cutting edge 171. Thus, the depth of the incision by the cutting edge 171 may be defined by the insertion depth of the blade 170 into the puncture tract 15. In some embodiments, the blade 170 (e.g., the proximal portion of the blade 170) may be insert molded into the body 110 via the body 110's injection molding process.

[0045] 2B and 2C show rear views of the device 100 in a closed and open state, respectively. The body 110 includes a first body portion 210A and a second body portion 210B. The channel 130 is disposed between the first body portion 210A and the second body portion 210B. A longitudinally oriented hinge 236 connects the first body portion 210A to the second body portion 210B along a first side of the channel 130 such that the first body portion 210A can rotate relative to the second body portion 210B between a closed state (FIG. 2B) and an open state (FIG. 2C). In the closed state (FIG. 2B), the catheter tube 51 and / or the guidewire 60 are laterally constrained within the channel 130. In the open state (FIG. 2C), the catheter tube 51 and / or the guidewire 60 can be laterally removed from the channel 130 through the gap 233. The hinge 236 may be a living hinge formed by an injection molding process of the body 110 .

[0046] In some embodiments, one or more frangible connecting members 237 may extend across the gap 233 between the first body portion 210A and the second body portion 210B when the first body portion 210A and the second body portion 210B are disposed in the closed position. The frangible connecting members 237 may prevent rotation of the first body portion 210A relative to the second body portion 210B, thereby preventing lateral removal of the catheter tube 51 and / or guidewire 60 from the channel 130 without intentional action by the clinician. The intentional act may include applying opposing forces 217A, 217B (e.g., compressive forces) to the protrusions 241A, 241B, respectively, thereby breaking the frangible connecting member 237 and rotating the first and second body portions 210A, 210B relative to one another to sufficiently widen the gap 233 to facilitate lateral removal of the catheter tube 51 and / or guidewire 60 from the channel 130 through the gap 233.

[0047] 3A and 3B, in some embodiments, the device 100 may optionally include a blade cover 370 for the blade 170. The blade cover 370 is configured to prevent contact with the cutting edge 171 when the blade cover 370 is placed in a safety position. FIG. 3A shows the blade cover 370 in a safety position, and FIG. 3B shows the blade cover 370 in a use position. In some embodiments, the blade cover 370 may be rotatably coupled to the body 110 such that the blade cover 370 may be rotated between the safety position and the use position. In some embodiments, although not shown, the blade cover 370 may include a detent configured to maintain the blade cover 370 in the safety position unless the clinician explicitly transitions the blade cover 370 away from the safety position. As can be understood by one of ordinary skill in the art, the blade cover 370 may be coupled to the body 110 in any suitable manner suitable for transitioning the blade cover 370 between the safety position and the use position.

[0048] Referring to FIG. 4, in some embodiments, the device 100 may optionally include a sheath 421 coupled to the body 110 at the distal end 111 of the body 110 such that the sheath 421 extends along the blade 170. FIG. 4 shows a side view of the device 100 including the optional sheath 421. The sheath 421 is generally configured to be inserted into the puncture tract 15 along with the blade 170. The channel 130 extends along the sheath 421. In some embodiments, the sheath 421 includes a taper 422 configured to expand the puncture tract 15 during insertion of the sheath 121 into the puncture tract 15. The sheath 421 may be integrally formed with the body 110. In use, the taper 422 may expand the puncture tract 15 as the blade 170 incises the skin adjacent the puncture tract 15. In some embodiments, the bottom edge 274 and sharp tip 172 of the blade 170 may be disposed within the wall 423 of the sheath 421 .

[0049] According to some embodiments, a method for placing a catheter in a patient's vasculature may include all or any subset of the following steps or processes. The method may be performed by a medical clinician in accordance with a medical procedure for the patient. The clinician may (i) insert a needle into the patient from the skin surface to the vessel lumen to define a puncture path, (ii) insert a guidewire through the puncture path into the patient's vasculature, and (iii) advance a catheter along the guidewire. The catheter includes a catheter tube having a tissue dissection device attached thereto, as described above. The clinician may further insert a tissue dissection device into the puncture path such that a blade of the tissue dissection device incise the skin adjacent the puncture path to enlarge the puncture path. After enlarging the puncture path, the clinician may laterally separate the tissue dissection device from the catheter tube and advance the catheter along the vasculature through the enlarged puncture path.

[0050] In some embodiments of the method, the clinician can insert the tissue cutting device into the puncture tract until the body of the tissue cutting device abuts the skin surface, resulting in the depth of the incision being limited by the insertion depth limited by the insertion stop.

[0051] In some embodiments, the tissue dissection device includes a sheath that extends along with the blade, such that the clinician inserts the sheath into the puncture tract. In some embodiments of the method, the sheath includes a taper configured to dilate the puncture tract during insertion of the sheath into the puncture tract. A clinician can dilate the puncture tract by inserting the sheath into the puncture tract.

[0052] In some embodiments of the method, the device includes a blade cover selectively transitionable between a safe state and a use state. The blade cover extends over the cutting edge in the safe state and is positioned away from the cutting edge in the use state. Thus, a clinician can transition the blade cover from the safe state to the use state. In some embodiments, the blade cover may be rotatably coupled to the body. Thus, a clinician can rotate the blade cover from the safe state toward the use state.

[0053] In some embodiments, the body includes a first body side coupled to a second body side via a longitudinally oriented hinge, and the channel is disposed between the first body side and the second body side. According to such embodiments, rotation of the second body side relative to the first body side transitions the channel between a closed state and an open state. The catheter is laterally constrained within the channel in the closed state, and the catheter is laterally removable from the channel in the open state.

[0054] In some embodiments of the method, the first body side includes a first lateral protrusion and the second body side includes a first lateral protrusion. The clinician may transition the channel from a closed state to an open state by applying a compressive force to the first and second protrusions. Thus, the clinician may also laterally remove the catheter tube from the channel in the open state. The clinician may also laterally remove the guidewire from the channel in the open state.

[0055] Some specific embodiments are disclosed herein, and although the specific embodiments are disclosed in some detail, the specific embodiments are not intended to limit the scope of the concept provided herein. Additional adaptations and / or modifications may be apparent to those skilled in the art, and the broader aspects also encompass these adaptations and / or modifications. Thus, one may deviate from the specific embodiments disclosed herein without departing from the scope of the concept provided herein.

Claims

1. 1. A tissue dissection device comprising: a body defining a distal end and a proximal end, the body includes a channel extending longitudinally along the body between the distal end and the proximal end; a body, the channel configured to receive a vascular catheter therein; a tissue cutting blade attached to the body, the blade comprising: extending distally from the distal end; a tissue dissecting blade extending laterally from the longitudinal axis of the channel such that a cutting edge of the blade is positioned on an opposite side of the longitudinal axis.

2. The device of claim 1 , wherein the device is configured to be inserted along a puncture tract extending between a patient's skin surface and a blood vessel wall.

3. The device of claim 1 , wherein the blade is configured to incise the patient's skin and dilate the puncture tract during insertion of the device.

4. The device of claim 2 , wherein the distal end of the body provides an insertion stop for the device during insertion of the device.

5. 5. The device of claim 1, wherein the cutting edge of the blade is positioned at an angle to the longitudinal axis of the channel such that a distal portion of the cutting edge is closer to the longitudinal axis of the channel than a proximal portion of the cutting edge.

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

7. A device according to any preceding claim, wherein the body includes one or more protrusions extending laterally therefrom, the protrusions defining a handle for the device.

8. The device of any one of claims 1 to 4, wherein the blade is formed from stainless steel.

9. the body is formed from a thermoplastic material by an injection molding process; The device of any one of claims 1 to 4, wherein the blade is insert molded into the body.

10. the body further includes a sheath extending distally from the distal end; the sheath extends along the blade; the channel extends along the sheath; The device of any one of claims 1 to 4, wherein the sharp distal tips of the blades are insert molded into the wall of the sheath.

11. The device of claim 10 , wherein the sheath includes a taper such that insertion of the sheath into the puncture tract causes the puncture tract to expand.

12. the device is configured to allow lateral separation of the device from the catheter in response to an intentional action by a clinician; The device of any one of claims 1 to 4, wherein the device is configured to prevent lateral separation of the device from the catheter in the absence of the intentional action by the clinician.

13. the body includes a first body side connected to a second body side via a longitudinally oriented hinge; the channel is disposed between the first body side and the second body side; the second body side is rotated relative to the first body side to transition the channel between a closed state and an open state; the catheter is laterally constrained within the channel in the closed state; The device of any one of claims 1 to 4, wherein the catheter is laterally removable from the channel in the open state.

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

15. a first protrusion of the one or more protrusions extending from the first body side; a second protrusion of the one or more protrusions extending from the second body side; The device of claim 13 , wherein applying a compressive force to the first and second protrusions transitions the channel from the closed state to the open state.

16. the body includes one or more frangible connecting members extending between the first body side and the second body side opposite the hinge, the one or more frangible connecting members restraining the channel in the closed state; 16. The device of claim 15, wherein application of the compressive force breaks the one or more frangible connecting members.

17. A blade cover selectively transitionable between a safe state and an in-use state, extending above the cutting edge in the safety state; The device according to any one of claims 1 to 4, comprising a blade cover that is arranged away from the cutting edge in the use state.

18. The blade cover is rotatably coupled to the body, 20. The device of claim 17, wherein transitioning the blade cover from the safe state to the use state includes rotating the blade cover.

19. 20. The device of claim 18, wherein rotation of the blade cover away from the safe condition is prevented by a detent.

20. a catheter configured to be advanced along the patient's vasculature; A catheter assembly comprising: a tissue dissection device according to any one of claims 1 to 4 coupled to the catheter.

21. The device of claim 20 , wherein the tissue dissection device is attached to the catheter via an adhesive.

22. 21. The device of claim 20, wherein the tissue dissection device is attached to the catheter adjacent a diameter transition portion of the catheter.

23. 21. The device of claim 20, wherein the tissue dissection device is attached to the catheter adjacent the distal end of the catheter.

24. 21. The device of claim 20, wherein, in use, manipulation of the catheter is assisted by grasping the tissue dissection device.

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