Tissue incision expander and method thereof

Abstract

The tissue dissecting dilator includes an elongate dilator body (102), a dilator tip (104), a plurality of retractable blades (122, 124), and a cap (108). The dilator body includes a plurality of longitudinal guide slots along a distal portion of the dilator body. The dilator tip is formed in the distal portion of the dilator body or is coupled to the distal end of the dilator body. The dilator tip includes a plurality of blade slots. The blades are disposed within the dilator body. The blades are configured to extend through the blade slots in at least a ready-to-expand state of the dilator to incise tissue surrounding an insertion site upon insertion into the insertion site. The cap is slidably disposed over the dilator body. The cap covers the dilator tip in at least a ready-to-expand state of the dilator.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to tissue dissection dilators and methods. [Background technology]

[0002] Prior to placing a catheter in a patient's blood vessel, it is common to incise the patient's skin around the needle tract at the insertion site in order to dilate the surrounding tissue with a dilator. Typically, incising the patient's skin and dilating the tissue around the needle tract are performed separately. In practice, incising is usually performed with a dedicated skin knicker or scalpel with a No. 11 blade. Dilating is usually performed with a dilator that is 2 French sizes larger than the catheter being placed. Attempts to integrate incising the patient's skin and dilating the tissue around the needle tract 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 dilator that safely integrates incising the patient's skin at the insertion site and dilating the tissue around the needle tract at the insertion site. Such a dilator would reduce procedure time and errors, for example, when placing a catheter at the insertion site.

[0003] Disclosed herein is a tissue dissection dilator and method that addresses the foregoing. Summary of the Invention

[0004] In some embodiments, disclosed herein is a tissue dissecting dilator including an elongate dilator body, a dilator tip, a plurality of retractable blades, and a cap. The dilator body includes a plurality of longitudinal guide slots along a distal portion of the dilator body. The dilator tip is formed at or coupled to a distal end of the dilator body. The dilator tip includes a plurality of blade slots. The blades are disposed within the dilator body. The blades are configured to extend through the blade slots at least in a ready-to-expand state of the dilator to incise tissue surrounding an insertion site upon insertion into the insertion site. The cap is slidably disposed over the dilator body. The cap covers the dilator tip at least in a ready-to-expand state of the dilator.

[0005] In some embodiments, the guide slots terminate as grooves in the dilator tip that provide a reinforcing structure to the dilator tip beyond that provided by the guide slots for tissue dilation by the dilator tip.

[0006] In some embodiments, the distal end of the blade is proximal to the distal end of the dilator or dilator tip. Having the distal end of the blade proximal to the distal end of the dilator or dilator tip allows at least the distal end of the dilator tip to engage the insertion site before cutting the tissue surrounding the insertion site.

[0007] In some embodiments, the blade includes two crossed blades coupled to a capture plate slidably disposed within the dilator body proximal to the dilator tip. In some embodiments, the two intersecting blades provide four orthogonal blade edges, each blade edge of said blade edges being orthogonal to its immediately adjacent blade edge.

[0008] In some embodiments, the capture plate is proximal to the distal tip in the ready-to-expand state of the expander. In some embodiments, the cap includes a plurality of cap projections that project toward the central axis of the dilator. The cap projections are disposed on at least a distal portion of the cap such that when the cap is slid proximally over the dilator body and past the dilator tip, the cap projections slide within the guide slots and engage the capture plate. Engaging the capture plate when the cap is slid proximally over the dilator body and past the dilator tip causes the blades to retract into the dilator body for subsequent dilation with the dilator without further dissecting the tissue surrounding the insertion site.

[0009] In some embodiments, the cap is configured to slide proximally over the dilator body by interaction with the skin surrounding the insertion site when the dilator tip is inserted into the insertion site.

[0010] In some embodiments, the capture plate includes a plurality of notches configured to engage the cap protrusions on the distal portion of the cap. The notches in the capture plate are perpendicular to the blades.

[0011] In some embodiments, a cap protrusion is further disposed on a proximal portion of the cap, the cap protrusion being configured to slide within the guide slot to eliminate any play between the proximal portion of the cap and the dilator body therebelow.

[0012] In some embodiments, the capture plate includes a stabilizer integral with or coupled to a proximal end of the capture plate. The stabilizer includes split legs configured to slidably engage an inner wall of the dilator body and mitigate tilt of the capture plate within the dilator body. Mitigating tilt of the capture plate within the dilator body keeps the blades properly aligned within the dilator body, thereby avoiding blade jamming.

[0013] In some embodiments, the dilator further includes a compression spring between the proximal end of the capture plate and a seat for the capture plate within the dilator body. The compression spring is configured to cushion the capture plate from tilting within the dilator body. By cushioning the capture plate from tilting within the dilator body, the blades remain properly aligned within the dilator body, thereby avoiding blade jamming.

[0014] In some embodiments, the compression spring is further configured to keep the blades extending through the blade slots in a ready-to-expand state of the expander, regardless of whether the expander is oriented partially along the gravity vector.

[0015] Also disclosed herein in some embodiments is another tissue dissecting dilator that includes an elongate dilator body, a dilator tip, and a pair of rotatable blades. The dilator tip is formed on or coupled to a distal portion of the dilator body. Each of the pair of blades has a geometric disk sector having a blade edge along its arc.

[0016] [ka]

[0017] Each of the pair of blades is positioned on opposite sides of the dilator such that when the dilator is inserted into the insertion site, the blades incise tissue on either side of the insertion site. In some embodiments, the blade is at the distal end of the dilator or proximal to the distal end of its dilator tip. Having a blade at the distal end of the dilator or proximal to the distal end of its dilator tip allows at least the distal end of the dilator tip to engage the insertion site before cutting the tissue surrounding the insertion site.

[0018] In some embodiments, each of the plurality of blades includes a primary tissue capture portion extending from a leading corner of the blade where the leading edge meets the edge of the blade, the primary tissue capture portion configured to capture tissue surrounding the insertion site and rotate the blade out of the dilator body to incise tissue surrounding the insertion site as the dilator is inserted into the insertion site.

[0019] In some embodiments, only a primary tissue capture extends from each side of the expander in the expander's ready-to-expand state. In some embodiments, each of the plurality of blades includes a secondary tissue capture portion at a central portion of the blade edge configured to capture additional tissue surrounding the insertion site, further rotate the blade away from the dilator body, and further dissect tissue surrounding the insertion site as the dilator is further inserted into the insertion site.

[0020] In some embodiments, each of the plurality of blades includes a tertiary tissue trap extending from a trailing corner of the blade where the trailing edge meets the edge of the blade, the tertiary tissue trap configured to trap tissue surrounding the insertion site and rotate the blade into the dilator body as the dilator is inserted into the insertion site without further dissecting the tissue surrounding the insertion site.

[0021] In some embodiments, each of the multiple blades is rotatably mounted on one of a pair of pins disposed in one of a pair of pin holes in a support frame, the frame optionally being split between the sides of the dilator that contain the blades.

[0022] In some embodiments, each of the pair of pins or a pin is located at the junction between the dilator body and the dilator tip. In some embodiments, the frame is centrally located on the expander along the longitudinal plane of symmetry.

[0023] Also disclosed herein in some embodiments is a method of tissue dissecting dilator, including a dilator insertion step, a tissue dissecting step, and a deactivation step. The dilator insertion step includes inserting a dilator tip of the dilator into an insertion site. The dilator insertion step initiates dilation of tissue surrounding the insertion site. The tissue dissecting step includes dissecting tissue surrounding the insertion site with a plurality of blades while inserting the dilator tip further into the insertion site. The blades are disposed within the dilator short of a distal end of the dilator or short of a distal end of its dilator tip. The deactivation step includes ceasing dissecting tissue surrounding the insertion site with the blades while inserting the dilator tip further into the insertion site. The blades retract or rotate into the dilator while inserting the dilator tip further into the insertion site.

[0024] In some embodiments, the cap of the dilator is adapted to slide proximally over the dilator during insertion of the dilator tip into the insertion site during the dilator insertion step, by interaction with the skin surrounding the insertion site, Sliding the cap proximally over the dilator exposes a blade for cutting tissue surrounding the insertion site.

[0025] In some embodiments, the blade comprises two crossed blades coupled to a capture plate slidably disposed within a dilator body of the dilator, the capture plate being disposed within the dilator body proximal to the dilator tip.

[0026] In some embodiments, the two intersecting blades provide four orthogonal blade edges, each blade edge of said blade edges being orthogonal to its immediately adjacent blade edge. In some embodiments, the cap is further adapted to slide proximally over the dilator during further insertion of the dilator tip into the insertion site during the tissue cutting step, by interaction with the skin surrounding the insertion site, such that sliding the cap further proximally over the dilator leaves the blade exposed for cutting the tissue surrounding the insertion site.

[0027] In some embodiments, the cap is further adapted to slide proximally over the dilator by interaction with the skin surrounding the insertion site while inserting the dilator tip further into the insertion site during the deactivation step, causing a cap projection of the cap extending through the guide slot of the dilator to engage the capture plate and retract the blade into the dilator to stop the blade from cutting tissue surrounding the insertion site.

[0028] In some embodiments, the primary tissue capture portion of the blade at the corresponding leading corner of the blade extends from the side of the dilator during the dilator insertion step to capture the skin surrounding the insertion site while inserting the dilator tip into the insertion site, and the blade is rotated out of the dilator to incise the tissue surrounding the insertion site by capturing the skin surrounding the insertion site while inserting the dilator tip into the insertion site.

[0029] In some embodiments, a secondary tissue capture of the blade at the center of the blade captures tissue surrounding the insertion site while the dilator tip is inserted further into the insertion site during the tissue cutting step. The blade continues to rotate away from the dilator to cut tissue surrounding the insertion site by capturing skin surrounding the insertion site while the dilator tip is inserted further into the insertion site.

[0030] In some embodiments, a tertiary tissue capture of the blade at a corresponding trailing corner of the blade captures tissue surrounding the insertion site while inserting the dilator tip further into the insertion site during the deactivation step. The blade is rotated into the dilator to stop the blade from cutting tissue surrounding the insertion site by capturing the skin surrounding the insertion site while inserting the dilator tip further into the insertion site.

[0031] 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]

[0032] [Figure 1] 1 shows a first tissue dissecting dilator in a ready-to-expand state with a cap over the dilator tip, whereby the cap covers a retractable blade extending through a blade slot in the dilator tip, according to some embodiments. [Diagram 2] 1 shows a first dilator in a relatively initial expanded state with a cap over a proximal portion of the dilator body, whereby the cap exposes blades extending through blade slots at the dilator tip, according to some embodiments. [Diagram 3] 1 shows a first dilator in a relatively late expanded state with a cap over a mid-portion of the dilator body and with the blades retracted into the dilator body, according to some embodiments. [Figure 4] 1A shows an end view of a distal end of a first dilator in a ready-to-expand state of the first dilator, according to some embodiments. FIG. [Diagram 5] 1A shows a detailed view of a distal portion of the first expander in a ready-to-expand state of the first expander, according to some embodiments. FIG. [Figure 6] 1A shows a detailed view of a distal portion of the first dilator in a relatively initial expanded state of the first dilator, according to some embodiments. [Figure 7] 1A shows a detailed view of a distal portion of the first dilator in a relatively later expanded state of the first dilator, according to some embodiments. [Figure 8] FIG. 13 shows a detailed view of the cap of the first dilator, according to some embodiments. [Figure 9] 1 shows a longitudinal cross-section of a cap of a first dilator, according to some embodiments. [Figure 10] 1A shows a detailed view of at least a distal portion of the first expander without a cap in a relatively later expanded state of the first expander, according to some embodiments. [Figure 11]1 illustrates a longitudinal cross-section of at least a distal portion of a first dilator including a first blade carriage and without a cap in a relatively later expanded state of the first dilator, according to some embodiments. [Figure 12] 1 illustrates a first blade carriage of a first dilator, according to some embodiments. [Figure 13] 1 illustrates an exploded view of a first blade carriage according to some embodiments. [Figure 14] 1 shows a longitudinal cross-section of at least a distal portion of the first dilator, including a second blade carriage, in a relatively later expanded state of the first dilator, and without a cap, according to some embodiments. [Figure 15] 13 illustrates a second blade carriage of a first dilator, according to some embodiments. [Figure 16] 1 illustrates an exploded view of a second blade carriage, according to some embodiments. [Figure 17] 13 shows a second tissue dissecting dilator in a ready-to-expand state with a proximally facing primary tissue capture portion of a pair of rotatable blades extending from the side of the dilator, according to some embodiments. [Figure 18] 13A shows a detailed view of a distal portion of a second tissue dissecting dilator in a ready-to-expand state with a primary tissue capture portion extending from the side of the dilator and facing proximally of the blade, according to some embodiments. [Figure 19] 13 shows a second tissue dissecting dilator in a relatively early to mid-expanded state with a secondary tissue trap extending from the side of the dilator and pointing proximally towards the blade, according to some embodiments. [Figure 20] A detailed view of a distal portion of a second tissue dissecting dilator in a relatively early to mid-expansion state with a secondary tissue capture portion extending from the side of the dilator and facing proximally of the blade, according to some embodiments. [Figure 21] 13 shows a second tissue dissecting dilator in a mid-tensioned state with a tertiary tissue trap extending from the side of the dilator and pointing proximally towards the blade, according to some embodiments. [Figure 22]13A shows a detailed view of a distal portion of a second tissue dissecting dilator in a mid-expanded state with a tertiary tissue trap extending from the side of the dilator and facing proximally of the blade, according to some embodiments. [Figure 23] 13 shows a second tissue dissecting dilator in a relatively mid-to-late expanded state in which the tertiary tissue trapping portion of the blade has rotated back into the side of the dilator, according to some embodiments. [Figure 24] 14A shows a detailed view of a distal portion of a second tissue dissecting dilator in a relatively mid-to-late expanded state in which the tertiary tissue capture portion of the blade has rotated back into the side of the dilator, according to some embodiments. [Diagram 25] 13 shows a second tissue dissecting dilator in a later expanded state with the blade rotated back into the side of the dilator, according to some embodiments. [Figure 26] 14 shows a detailed view of a distal portion of a second tissue dissecting dilator in a later expanded state with the blades rotated back into the sides of the dilator, according to some embodiments. [Figure 27] 13 shows an exploded view of a second tissue dissection dilator, according to some embodiments. [Figure 28] 13 shows a detailed exploded view of a distal portion of a second tissue dissection dilator, according to some embodiments. [Figure 29] 1 illustrates a detailed view of one blade of a pair of blades according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] 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.

[0034] 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, any of the aforementioned features or steps may further include one or more 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 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 "the" also include plural references unless the context clearly dictates otherwise.

[0035] With respect to "proximal," a "proximal portion" or "proximal section," e.g., of a dilator, includes a portion or section of the dilator that is intended to be near the clinician when the dilator is used on a patient. Similarly, a "proximal length," e.g., of a dilator, includes the length of the dilator that is intended to be near the clinician when the dilator is used on a patient. A "proximal end," e.g., of a dilator, includes the end of the dilator that is intended to be near the clinician when the dilator is used on a patient. The proximal portion, section, or length of a dilator can include the proximal end of the dilator. However, the proximal portion, section, or length of a dilator need not include the proximal end of the dilator. That is, unless the context suggests otherwise, the proximal portion, section, or length of a dilator is not the terminal portion or terminal length of the dilator.

[0036] With respect to "distal," a "distal portion" or "distal section," e.g., of a dilator, includes a portion or section of the dilator that is intended to be near or within a patient when the dilator is used on a patient. Similarly, a "distal length," e.g., of a dilator, includes a length of the dilator that is intended to be near or within a patient when the dilator is used on a patient. A "distal end," e.g., of a dilator, includes an end of the dilator that is intended to be near or within a patient when the dilator is used on a patient. A distal portion, section, or length of a dilator can include the distal end of the dilator. However, a distal portion, section, or length of a dilator need not include the distal end of the dilator. That is, unless the context suggests otherwise, a distal portion, section, or length of a dilator is not a terminal portion or length of the dilator.

[0037] 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. As discussed above, it is common to incise the patient's skin around the needle tract at the insertion site in order to dilate the surrounding tissue with a dilator prior to placing a catheter in a patient's blood vessel. Typically, incising the patient's skin and dilating the tissue around the needle tract are performed separately. In practice, incising is usually performed with a dedicated skin knicker or scalpel with a No. 11 blade. Dilating is usually performed with a dilator that is 2 French sizes larger than the catheter being placed. Attempts to integrate incising the patient's skin and dilating the tissue around the needle tract have resulted in spring-loaded blades that are generally considered unsafe due to the clinician's lack of control over the blade. What is needed is a tissue dissection dilator that safely integrates incising the patient's skin at the insertion site and dilating the tissue around the needle tract at the insertion site. Such a dilator would reduce procedure time and errors, for example, when placing a catheter at an insertion site.

[0038] Disclosed herein is a tissue dissection dilator and method that addresses the foregoing. Expander 1-17 show a first tissue dissection dilator 100 according to some embodiments.

[0039] As shown, the dilator 100 includes an elongate dilator body 102, a dilator tip 104, a blade carriage 106, and a cap 108. The dilator body 102 includes a plurality of longitudinal guide slots 110 along a distal portion of the dilator body 102. The guide slots 110 terminate distally in open-ended grooves 112 in the dilator tip 104 that provide the dilator tip 104 with a reinforcing structure (e.g., connecting or bridging portions) beyond that provided by the guide slots 110 for tissue expansion by the dilator tip 104. The guide slots 110 and grooves 112 are configured to receive the cap projections 134 therein for sliding the cap 108 proximally over the dilator body 102. In particular, one or more of the guide slots 110 can include up to at least one pair of guide slot catches 114 per guide slot. Such a trap is configured to restrict the cap 108 from sliding distally over the dilator tip 104 in the ready-to-expand state of the dilator 100 by preventing the cap protrusion 134 of a proximal portion of the cap 108, which is proximal to the guide slot trap 114 in the ready-to-expand state of the dilator 100, from passing therethrough. Such a trap is also configured to restrict the cap 108 from sliding distally back over the dilator body 102 in the later expanded state of the dilator 100 by preventing the cap protrusion 134 of a distal portion of the cap 108, which is proximal to the guide slot trap 114 in the later expanded state of the dilator 100, from passing therethrough. In addition, the guide slot 110 terminates proximally at a terminal end 116, for example, at a mid-portion of the dilator body 102. Such end portions are configured to limit the cap 108 from sliding excessively proximally over the dilator body 102 by preventing the end portion from passing over the cap protrusions 134 on either the proximal or distal portions of the cap 108.

[0040] The dilator tip 104 is formed on or coupled to the distal end of the dilator body 102. The dilator tip 104 includes a plurality of blade slots 118 at right angles to the guide slots 110 and configured to extend blades 122 through the guide slots. In particular, the distal ends of the blade slots 118 are proximal to the distal end of the dilator 100 or its dilator tip 104. Having the distal ends of the blade slots 118 proximal to the distal end of the dilator 100 or its dilator tip 104 allows at least the distal end of the dilator tip 104 to engage the insertion site before the blades 122 cut the tissue surrounding the insertion site.

[0041] The blade carriage 106 is slidably disposed on the dilator body 102 such that its capture plate 120 is proximal to the dilator tip 104 in the ready-to-dilate state of the dilator 100. The blade carriage 106 includes a plurality of retractable blades 122 coupled to the capture plate 120, the blades 122 being retractable in response to sliding the blade carriage 106 proximally by the cap 108 when the cap 108 is slid proximally over the dilator body 102.

[0042] The blade 122 is configured to extend through the blade slot 118 in at least the ready-to-expand state of the dilator 100 to cut tissue surrounding the insertion site upon insertion into the insertion site. However, the distal end of the blade 122 is proximal to the distal end of the dilator 100 or its dilator tip 104. Having the distal end of the blade 122 proximal to the distal end of the dilator 100 or its dilator tip 104 allows at least the distal end of the dilator tip 104 to engage the insertion site before the blade 122 cuts tissue surrounding the insertion site.

[0043] The blades 122 may include two crossed blades coupled to the capture plate 120. However, the blades 122 are not limited to two crossed blades, as fewer or more blades 122 may be used, crossed or uncrossed, for the same or different functions. However, the two crossed blades provide four orthogonal blade edges 124, with each blade edge of the blade edges 124 being orthogonal to its immediately adjacent blade edge 124. Advantageously, the blades 122 cut the tissue in an "X" shaped incision along two orthogonal planes, with each incision along the two orthogonal planes being relatively shorter than the incision required in existing methods such as those described above. Such an "X" shaped incision of the tissue maximizes the so-called opening response of the tissue, resulting in less tension in the tissue and therefore lower insertion forces, thereby reducing damage to the tissue.

[0044] The capture plate 120 can include one or more slots or recesses 126 into which the proximal ends of the blades 122 are disposed in a neutral or interference fit. In addition to or as an alternative to the aforementioned fits, the proximal ends of the blades 122 can be mated to one or more slots or recesses 126 in the capture plate 120.

[0045] The capture plate 120 can include a number of distally opening notches 128 configured to engage cap protrusions 134 on the distal portion of the cap 108. Indeed, when the cap 108 is slid proximally over the dilator body 102 and past the dilator tip 104, the notches 128 engaging the cap protrusions 134 cause the blade carriage 106 to slide proximally within the dilator body 102, thereby retracting the blades 122 into the dilator body 102 for subsequent dilation of the insertion site with the dilator 100 without further dissecting the tissue surrounding the insertion site. The notches 128 can vary in number depending on the cap protrusions 134, but FIG. 12 shows four perpendicular notches, with each of the notches 128 forming a right angle with its immediate neighbors. However, the notches 128 in the capture plate 120 are equiangularly alternating at 45° with the blade edge 124, the proximal end of the blade 122, or one or more slots or recesses 126 in the capture plate 120 to provide maximum circumferential clearance between the blade edge 124 and the cap protrusion 134.

[0046] The capture plate 120 can include a stabilizer 130 integral with or coupled to a proximal end of the capture plate 120. The stabilizer 130 includes split legs 132 configured to slidably engage an inner wall of the dilator body 102. The split legs 132 of the stabilizer 130 are configured, for example, in combination with one or more inner wall protrusions that protrude from the inner wall of the dilator body 102 to form a stop mechanism in the proximal portion of the dilator body 102 to stop the blade carriage 106 from sliding too far proximally within the dilator body 102, despite the termination 116 of the guide slot 110. Advantageously, when the stabilizer 130, the one or more inner wall protrusions, and the guide slot catch 114 are present in the dilator 100, the blade carriage 106 can be locked into a proximal position in the dilator body 102 by a combination of the cap protrusion 134 proximal to the guide slot catch 114 in the guide slot 110, the cap protrusion 134 disposed in the notch 128 of the capture plate 120, and the split leg 132 of the stabilizer 130 distal to the one or more inner wall protrusions when the blade carriage 106 is slid proximally into position during dilation using the dilator 100. In this manner, the aforementioned features provide an integrated single-use implementation mechanism for implementing a single use of each dilator, such as the dilator 100. In particular, the stabilizer 130 can mitigate tilting of the capture plate 120 within the dilator body 102. Mitigates the tilt of the capture plate 120 within the dilator body 102, keeping the blades 122 properly aligned within the dilator body 102, thereby avoiding jamming of the blades against, for example, the inner walls of the dilator body 102 or the inner walls of the dilator tip 104 adjacent the blade slot 118, as the blade carriage 106 is slid proximally within the dilator body 102.

[0047] The cap 108 is slidably disposed over the dilator body 102. The cap 108 covers the dilator tip 104 and provides a safety for the blades 122 extending through the blade slots 118 of the dilator tip 104, at least in the ready-to-dilate state of the dilator 100. Notably, the cap 108 is configured to slide proximally over the dilator body 102 by interaction with the skin surrounding the insertion site as the dilator tip 104 is inserted into the needle tract at the insertion site. In fact, the skin surrounding the insertion site pushes the cap 108 to slide proximally over the dilator body 102 as the dilator tip 104 is advanced into the needle tract.

[0048] The cap 108 includes a plurality of cap protrusions 134 that protrude toward a central axis of the dilator 100. The cap protrusions 134 are disposed on at least a distal portion of the cap 108 such that when the cap 108 is slid proximally over the dilator body 102 and past the dilator tip 104, the cap protrusions 134 slide within the guide slots 110 and engage the notches 128 of the capture plate 120. When the cap 108 is slid proximally over the dilator body 102 and past the dilator tip 104, the cap protrusions 134 engaging the notches 128 of the capture plate 120 cause the blade carriage 106 to slide proximally within the dilator body 102, thereby retracting the blades 122 into the dilator body 102 for subsequent dilation of the insertion site with the dilator 100 without further dissecting the tissue surrounding the insertion site. In particular, a cap protrusion 134 or a protruding ring can be further disposed on the proximal portion of the cap 108. The cap protrusion 134 on the proximal portion of the cap 108 can be configured to slide within the guide slot 110 and eliminate any play between the proximal portion of the cap 108 and the dilator body 102 therebelow. However, the cap protrusion 134 or the protruding ring on the proximal portion of the cap 108 can be configured to slide over the dilator body 102 outside the guide slot 110 and also eliminate any play between the proximal portion of the cap 108 and the dilator body 102 therebelow.

[0049] Although not shown, the dilator 100 may further include a compression spring. If present, the compression spring may be between, and optionally coupled to, the proximal end of the capture plate 120 and a seat for the compression spring in the dilator body 102, such as the seat of one or more of the interior walls described above. If present, the compression spring keeps the blades 122 of the blade carriage 106 extending through the blade slots 118 of the dilator tip 104 in the dilator 100 ready to expand state, regardless of whether the dilator 100 is partially oriented along the gravity vector or not. Similar to the stabilizer 130, the compression spring may also mitigate the tilt of the capture plate 120 within the dilator body 102. As described above, reducing the tilt of the capture plate 120 within the dilator body 102 keeps the blades 122 properly aligned within the dilator body 102, thereby avoiding blade jamming.

[0050] 8-29 show a second tissue dissection dilator 200 according to some embodiments. As shown, the dilator 200 includes an elongate dilator body 202 , a dilator tip 204 , a support frame 236 , and a pair of rotatable blades 238 .

[0051] The dilator tip 204 is formed on a distal portion of the dilator body 202 or is coupled to the distal end of the dilator body 202. In either case, the dilator 200 includes a pair of blade slots 240 on the sides of the dilator 200 between the dilator tip 204 and the dilator body 202 that are configured to rotate the blades 238 out of the dilator 200 in a ready-to-expand state of the dilator 200 and back into the dilator 200 from a mid-expansion state of the dilator 200 to a relatively late-expansion state of the dilator 200. In particular, the distal ends of the blade slots 240 are short of the distal end of the dilator 200 or short of the distal end of its dilator tip 204. Having the distal end of the blade slot 240 before the distal end of the dilator 200 or before the distal end of its dilator tip 204 allows at least the distal end of the dilator tip 204 to engage the insertion site before the blade 238 cuts the tissue surrounding the insertion site.

[0052] The frame 236 is located in the center of the dilator 200 between the dilator tip 204 and the dilator body 202 and supports the blades 238 so that the blades 238 rotate out of the dilator 200 in a ready-to-expand state of the dilator 200 and rotate back into the dilator 200 from a mid-expansion state of the dilator 200 to a relatively late expansion state of the dilator 200. The frame 236 is optionally a single piece, two pieces split between the top and bottom halves of the dilator 200 defined to be on either side of a first longitudinal plane of symmetry of the dilator 200 including the frame 236 and the blades 238, or four pieces split between the top and bottom halves of the dilator 200 and between the left and right sides of the dilator 200 defined to be on either side of a second longitudinal plane of symmetry of the dilator 200 perpendicular to the first longitudinal plane of symmetry. In any event, the frame 236 includes a pair of pin holes 242 that are located at the transition or junction between the dilator tip 204 and the dilator body 202, but symmetrically positioned between the left and right sides of the dilator 200. One pin of a pair of pins 244 is located in each hole of the pin holes 242, and each blade of the blades 238 is rotatably mounted on one of the aforementioned pins 244.

[0053] Notwithstanding the pins 244 to which the blades 238 are rotatably mounted, the frame 236 includes a pair of blade locking pins 246 proximal to the pin holes 242 at the transition or junction between the dilator tip 204 and the dilator body 202. The blade locking pins 246 are configured to insert into the blade locking holes 260 of the blades 238 when the blades 238 rotate their respective blade locking holes 260 over the blade locking pins 246 in a relatively later expanded state of the dilator 200. Advantageously, both the blade locking pins 246 and the blade locking holes 260 function in cooperation to lock the blades 238 within the dilator body 202 in a relatively later expanded state of the dilator 200, thereby ceasing to cut tissue surrounding the insertion site even as the dilator 200 continues to be inserted into the insertion site. In this manner, the aforementioned features provide an integrated single-use implementation mechanism for implementing a single use of each dilator, such as the dilator 200.

[0054] Each blade of the blades 238 is positioned on an opposite side (e.g., left or right side) of the dilator 200 such that the blades 238 cut tissue on either side of the insertion site upon insertion of the dilator 200 into the insertion site. However, the blades 238 are before the distal end of the dilator 200 or before the distal end of its dilator tip 204. Having the blades 238 before the distal end of the dilator 200 or before the distal end of its dilator tip 204 allows at least the distal end of the dilator tip 204 to engage the insertion site before cutting tissue surrounding the insertion site.

[0055] Each blade of the blades 238 is a geometric disk sector having a radius, such as a leading radius of the leading edge 248 or a trailing radius of the trailing edge 250, as well as a blade edge 252 along the arc between the aforementioned radii or edges 248 and 250.

[0056] [ka]

[0057] Each blade of the blades 238 includes a primary tissue capture 254 (e.g., a hook) extending from a leading corner of the blade where the leading edge 248 meets the blade edge 252. The primary tissue capture 254 is configured to capture tissue surrounding the insertion site and rotate its corresponding blade out of the dilator body 202 to incise the tissue surrounding the insertion site as the dilator 200 is inserted into the insertion site. Notably, in the ready-to-expand state of the dilator 200, only the primary tissue capture 254 extends from each side of the dilator 200. Each blade of the blades 238 also includes a secondary tissue capture 256 (e.g., a hook, but less prominent than the hook of the primary tissue capture 254) in the center of the blade edge 252. The secondary tissue capture portion 256 is configured to capture more tissue surrounding the insertion site and to rotate its corresponding blade further out of the dilator body 202 and to further dissect the tissue surrounding the insertion site as the dilator 200 is further inserted into the insertion site. Each blade of the blades 238 also includes a tertiary tissue capture portion 258 that includes a trailing corner of the blade where the trailing edge 250 meets the blade edge 252. The tertiary tissue capture portion 258 is configured to capture more tissue surrounding the insertion site and to rotate its corresponding blade into the dilator body 202 without further dissecting the tissue surrounding the insertion site as the dilator 200 is inserted into the insertion site.

[0058] The blades 238 also have blade lock holes 260, with each blade of the blades 238 having a blade lock hole along its trailing edge 250. Such blade lock holes are configured to receive the insertion of the blade lock pins of the blade lock pins 246 when the corresponding blades are rotated on the blade lock pins in the relatively later expanded state of the dilator 200. Advantageously, both the blade lock holes 260 and the blade lock pins 246 function in cooperation to lock their corresponding blades 238 within the dilator body 202 in the relatively later expanded state of the dilator 200, thereby ceasing to cut tissue surrounding the insertion site even if the dilator 200 continues to be inserted into the insertion site. In this manner, the aforementioned features provide an integrated single-use implementation mechanism for implementing a single use of each dilator, such as the dilator 100.

[0059] 17-26 show the dilator 200 in various states, ranging from a ready-to-expand state to a relatively later expanded state of the dilator 200, illustrating how the features of the blades 238, including the various tissue traps (i.e., primary tissue trap 254, secondary tissue trap 256, and tertiary tissue trap 258), function when the dilator 200 is used to expand a needle tract at an insertion site. Indeed, FIGS. 17 and 18 show the dilator 200 in its ready-to-expand state, where the primary tissue traps 254 of each blade of the blades 238 face proximally and extend from the sides (e.g., the left and right sides) of the dilator 200. Additionally, the primary tissue traps 254 are configured to trap tissue surrounding the insertion site and rotate the blades 238 out of the dilator body 202 to incise tissue surrounding the insertion site as the dilator 200 is inserted into the insertion site.

[0060] 19 and 20 show the dilator 200 in a relatively early to mid-expanded state of the dilator 200, where the secondary tissue traps 256 of each blade of the blades 238 face proximally and extend from a side of the dilator 200, according to some embodiments. The secondary tissue traps 256 are also configured to further trap tissue surrounding the insertion site and further rotate the blades 238 out of the dilator body 202 to further dissect tissue surrounding the insertion site as the dilator 200 is further inserted into the insertion site. FIGS. 21 and 22 show the dilator 200 in a mid-expanded state of the dilator 200, where the tertiary tissue traps 258 of each blade of the blades 238 face proximally and extend from a side of the dilator 200, according to some embodiments. Additionally, the tertiary tissue capture portion 258 is configured to capture tissue surrounding the insertion site as the expander 200 is inserted into the insertion site, allowing the blade 238 to be rotated into the expander body 202 without further incising the tissue surrounding the insertion site.

[0061] 23 and 24 show the dilator 200 in a relatively mid-to-late expanded state of the dilator 200 where the tertiary tissue traps 258 of each blade of the blades 238 have rotated back into the sides of the dilator 200, according to some embodiments. Finally, FIGS. 25 and 26 show the dilator 200 in a relatively later expanded state of the dilator 200 where the blades 238 have rotated back into the sides of the dilator 200, according to some embodiments. In particular, each blade of the blades 238 rotates approximately 330° from the ready-to-expand state of the dilator 200 to the relatively later expanded state of the dilator 200.

[0062] method The method includes a method of using the expander 100 or 200. For example, the method of using the expander 100 or 200 includes one or more steps selected from a expander insertion step, a tissue incision step, and a deactivation step.

[0063] The dilator insertion step involves inserting at least the distal end of the dilator tip 104 or 204 into the needle tract at the insertion site (e.g., the needle tract from the area of ​​skin to the lumen of a blood vessel) after the needle tract has been established with an introducer needle. The dilator insertion step initiates dilation of the tissue surrounding the insertion site.

[0064] The tissue cutting step involves cutting the tissue surrounding the insertion site with the blade 122 or 238 while further inserting the dilator tip 104 or 204 into the insertion site. As described above, the blade 122 or 238 is positioned on the dilator 100 or 200 prior to the distal end of the dilator tip 104 or 204 such that at least the distal end of the dilator tip 104 or 204 can engage the insertion site in the dilator insertion step prior to cutting the tissue surrounding the insertion site with the blade 122 or 238 in the tissue cutting step.

[0065] The deactivation step involves ceasing to use the blade 122 or 238 to cut tissue surrounding the insertion site while inserting the dilator tip 104 or 204 further into the insertion site. When the dilator 100 is used, the blade 122 retracts into the dilator 100 while inserting the dilator tip 104 further into the insertion site. However, when the dilator 200 is used, the blade 238 rotates into the dilator 200 while inserting the dilator tip 204 further into the insertion site.

[0066] Referring to the dilator 100 for its description in the preceding steps, the cap 108 of the dilator 100 is adapted to slide proximally over the dilator 100 by interaction with the skin surrounding the insertion site during insertion of the dilator tip 104 into the insertion site during a dilator insertion step. Sliding the cap 108 proximally over the dilator 100 exposes the blade 122 for incising tissue surrounding the insertion site. The cap 108 is further adapted to slide proximally over the dilator 100 by interaction with the skin surrounding the insertion site during further insertion of the dilator tip 104 into the insertion site during a tissue incision step. Sliding the cap 108 further proximally over the dilator 100 keeps the blade 122 exposed for incision of tissue surrounding the insertion site. The cap 108 is further adapted to slide proximally over the dilator 100 by interaction with the skin surrounding the insertion site while inserting the dilator tip 104 further into the insertion site during the deactivation step. Sliding the cap 108 proximally over the dilator 100 causes the cap projections 134 extending through the guide slots 110 of the dilator 100 to engage the capture plate 120 and retract the blades 122 into the dilator 100 to stop the blades 122 from cutting tissue surrounding the insertion site.

[0067] Referring to the dilator 200 for its description in the previous steps, the primary tissue capture 254 of each blade of the blade 238 at the corresponding leading corner of the blade 238 extends from the side of the dilator 200 and captures the skin surrounding the insertion site while inserting the dilator tip 204 into the insertion site during the dilator insertion step. The blade 238 is rotated away from the dilator 200 by capturing the skin surrounding the insertion site while inserting the dilator tip 204 into the insertion site to incise the tissue surrounding the insertion site. The secondary tissue capture 256 of each blade of the blade 238 at the center of the blade 238 captures the tissue surrounding the insertion site while further inserting the dilator tip 204 into the insertion site during the tissue incision step. The blade 238 continues to rotate away from the dilator 200 to incise the tissue surrounding the insertion site by capturing the skin surrounding the insertion site while further inserting the dilator tip 204 into the insertion site. The tertiary tissue capture 258 of each blade 238 at the corresponding trailing corner of the blade 238 captures tissue surrounding the insertion site while inserting the dilator tip 204 further into the insertion site during the deactivation step. The blade 238 is rotated into the dilator 200 to stop the blade 238 from cutting tissue surrounding the insertion site by capturing the skin surrounding the insertion site while inserting the dilator tip 204 further into the insertion site.

[0068] 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 dilator, comprising: an elongate dilator body including a plurality of longitudinal guide slots along a distal portion of the dilator body; a dilator tip formed in a distal portion of the dilator body or coupled to the distal end of the dilator body, the dilator tip including a plurality of blade slots; a plurality of retractable blades disposed within the dilator body and configured to extend through the blade slots in at least a ready-to-expand state of the dilator to incise tissue surrounding the insertion site upon insertion into the insertion site; a cap slidably disposed over the dilator body and covering the dilator tip when the dilator is in at least a ready-to-expand state; A tissue incision dilator comprising:

2. 2. The tissue dissection dilator of claim 1, The guide slot terminates as a groove in the tip of the dilator; A tissue dissecting dilator wherein the grooves provide a reinforcement structure to the dilator tip beyond that provided by guide slots for tissue dilation by the dilator tip.

3. 3. The tissue dissection dilator according to claim 1, A tissue dissecting dilator, wherein the distal ends of the plurality of blades are proximal to the distal end of the dilator or the distal end of its dilator tip, thereby enabling at least the distal end of the dilator tip to engage the insertion site before incising the tissue surrounding the insertion site.

4. In the tissue incision dilator according to claim 1 or 2, A tissue dissecting dilator, wherein the plurality of blades includes two intersecting blades coupled to a capture plate slidably disposed within the dilator body proximal to the dilator tip.

5. 5. The histotomy dilator of claim 4, The two intersecting blades provide four orthogonal blade edges; A tissue dissection dilator wherein each of said four blade edges is perpendicular to its immediately adjacent blade edge.

6. 5. The histotomy dilator of claim 4, The capture plate is located proximal to the distal tip when the dilator is in the ready-to-expand state. A tissue dissection expander.

7. 5. The histotomy dilator of claim 4, the cap includes a plurality of cap protrusions protruding toward the central axis of the dilator; The cap protrusion is positioned on at least a distal portion of the cap such that when the cap is slid proximally over the dilator body past the dilator tip, the cap protrusion slides within the guide slot and engages the capture plate, thereby retracting the multiple blades into the dilator body for dilation with the dilator without further incising the tissue surrounding the insertion site.

8. 8. The histotomy dilator of claim 7, A tissue dissection dilator, wherein the cap is configured to slide proximally over the dilator body by interaction with the skin surrounding the insertion site when the dilator tip is inserted into the insertion site.

9. 8. The histotomy dilator of claim 7, the capture plate includes a plurality of notches configured to engage the cap protrusions of the distal portion of the cap; A tissue dissection dilator, wherein the notches in the capture plate are perpendicular to the plurality of blades.

10. 8. The histotomy dilator of claim 7, The cap protrusion is further disposed on the proximal portion of the cap; A tissue dissection dilator, wherein the cap protrusion on the proximal portion of the cap is configured to slide within the guide slot to eliminate any play between the proximal portion of the cap and the underlying dilator body.

11. 5. The histotomy dilator of claim 4, the capture plate includes a stabilizer integral with or coupled to a proximal end of the capture plate; the stabilizer includes split legs configured to slidably engage an inner wall of the dilator body and mitigate tilting of the capture plate within the dilator body; This maintains the plurality of blades in proper alignment within the dilator body, thereby avoiding blade jamming.

12. The histotomy dilator according to claim 4 further comprises: a compression spring disposed between the proximal end of the capture plate and a seat for the capture plate within the dilator body; A tissue dissecting dilator, wherein the compression spring is configured to mitigate tilting of the capture plate within the dilator body, thereby keeping the plurality of blades properly aligned within the dilator body and avoiding blade jamming.

13. 13. The histotomy dilator of claim 12, The tissue dissection dilator, wherein the compression spring is further configured to maintain the plurality of blades extending through the blade slots in a dilator ready to be expanded state, regardless of whether the dilator is oriented partially along a gravity vector.

14. 1. A tissue incision dilator, comprising: an elongated dilator body; a dilator tip formed on a distal portion of the dilator body or coupled to the distal end of the dilator body; a pair of rotatable blades, each of said pair of blades being a geometric disk sector having a blade edge along its arc; 【Chemical 1】 a pair of blades having a shape similar to that of the dilator and positioned on opposite sides of the dilator such that when the dilator is inserted into the insertion site, the blades incise tissue on either side of the insertion site; A tissue incision dilator comprising:

15. 15. The tissue dissection dilator of claim 14, A tissue dissecting dilator, wherein the plurality of blades are located at the distal end of the dilator or proximal to the distal end of the dilator tip, thereby allowing at least the distal end of the dilator tip to engage the insertion site prior to incising the tissue surrounding the insertion site.

16. 16. The tissue dissection dilator according to claim 14 or 15, each of the plurality of blades includes a primary tissue capture portion extending from a leading corner of the blade where the leading edge meets the edge of the blade; A tissue dissecting dilator, wherein the primary tissue capturing portion is configured to capture tissue surrounding the insertion site and rotate the blade out of the dilator body to dissect the tissue surrounding the insertion site as the dilator is inserted into the insertion site.

17. 17. The tissue dissection dilator of claim 16, A tissue dissecting dilator in which only a primary tissue capture portion extends from each side of the dilator in the dilator's ready-to-expand state.

18. 17. The tissue dissection dilator of claim 16, each of the plurality of blades includes a secondary tissue capture portion at a central portion of the blade edge; A tissue dissecting dilator, wherein the secondary tissue capturing portion is configured to further capture tissue surrounding the insertion site, further rotate the blade out of the dilator body, and further dissect tissue surrounding the insertion site as the dilator is further inserted into the insertion site.

19. 17. The tissue dissection dilator of claim 16, each of the plurality of blades includes a tertiary tissue capture portion extending from a trailing corner of the blade where the trailing edge meets the edge of the blade; A tissue dissecting dilator, wherein the tertiary tissue capturing portion is configured to capture tissue surrounding the insertion site and rotate the blade into the dilator body as the dilator is inserted into the insertion site without further dissecting the tissue surrounding the insertion site.

20. 17. The tissue dissection dilator of claim 16, each of the plurality of blades is rotatably mounted on one of a pair of pins disposed in one of a pair of pin holes of a support frame; A tissue dissecting dilator, wherein a frame is optionally divided between sides of the dilator including said plurality of blades.

21. 21. The tissue dissection dilator of claim 20, A tissue dissection dilator, wherein each of the pair of pins is disposed at a junction between the dilator body and the dilator tip.

22. 21. The tissue dissection dilator of claim 20, A tissue dissection dilator, wherein the frame is positioned at the center of the dilator along a longitudinal plane of symmetry.

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