Background

[0001] Percutaneous techniques revolutionized vascular cannulation. They essentially eliminated the need for open cutdown procedures and the associated wound-related morbidity. However, initial percutaneous techniques left the operating physician or clinician exclusively reliant upon the relationships between surface anatomic landmarks and the underlying deep anatomic structures. While techniques have improved, and clinicians now insert more than five million percutaneous central venous catheters (CVCs) annually, there remains an overall complication rate of 15%. These complications include infection, thrombosis, occlusion, and, in particular, mechanical complications which usually occur during insertion and are intimately related to the anatomic relationships of the central veins.

[0002] There are currently multiple different methods for placement of a central venous catheter (CVC).The most common methods are: Peripherally Inserted Central Catheter (PICC), an Implanted Venous Port, an External Non-Tunneled Central Venous Catheter, a Tunneled Central Venous Catheter, and a Femoral Vein catheter.

[0003] The internal jugular vein (IJV) has become the preferred access site for central venous cannulation because of demonstrated reduced complication rates, including reduced rates of thrombosis, pneumothorax, and avoidance of catheter “pinch-off’ syndrome. Advantages of accessing the IJV include a superficial location, easy ultrasonic visualization, and a straight course to the superior vena cava (from the right). Internal jugular cannulation avoids the subclavian“pinch-off syndrome.” Furthermore, for renal failure patients, IJV cannulation avoids potential subclavian vein stenosis which would preclude use of the extremity for

hemodialysis access via arteriovenous shunt/fistula. There are three

percutaneous approaches to the IJV: anterior, central, and posterior.

[0004] Most tunneled CVC that are now placed utilize a two“stick” (incision) approach. This involves an incision to access the IJV with placement of a peel away sheath and a second incision laterally to form a subcutaneous tunnel. The CVC is then placed through the subcutaneous tunnel and looped back through the peel away sheath into the superior vena cava (SVC). In this procedure, the tunnel is made in the soft tissues anterior to the sternocleidomastoid muscle (SCM).

[0005] A single stick placement was first described by Bradley Glenn MD in the Journal of Vascular Interventional Radiology in 2007. He used ultrasound to guide the needle for puncture of the IJV and then used a straight dilator with a hand made or hand-bent curve to tunnel anteriorly to the SCM through the soft tissues.

[0006] Existing systems utilize straight vascular dilators for the placement of CVCs. In this regard, conventional CVC kits generally comprise at least four separate components, namely, a syringe coupled to a needle having a longitudinal lumen, a guide wire, multiple progressively sized straight dilators, and a CVC. Multiple straight dilators are advanced over the guide wire to dilate tissue and vein around the guide wire to facilitate the CVC and are withdrawn prior to the CVC being placed in the access pathway created by the dilator.

[0007] In addition to vascular dilation of blood vessels, dilators are commonly used for soft tissue dilation in multiple interventional procedures including, for example, access to the kidneys, stomach, liver, peritoneal cavity, and for abscess drainage and the dilation of urethral strictures. Generally, the vascular, renal, and fascial dilation applications involve exchanging multiple dilators of progressively larger diameters until the final subcutaneous tract is sufficiently large for the requisite application. These progressively larger dilators are typically provided in a kit 20 including a catheter, multiple dilators 22 in an increasing spectrum of sizes (e.g., 8 FR - 30 FR), and a variety of corresponding sheaths 24, as shown in prior art FIG. 1. This approach requires multiple-component dilator systems at greater cost, and also mandates less-efficient, multiple-step methods of use for forming subcutaneous tracts or pathways within the body.

[0008] Moreover, there are occasions when because of radiation, postoperative scarring, lymphadenopathy, or other etiologies, there are blockages or strictures in certain structures including the arteries, veins, ureters, intestines, bile ducts and many other structures which lead to significant health problems. Previously this has been addressed by dilating the structure with an angioplasty balloon catheter. However, angioplasty alone has many limitations including whether access can be obtained across the blockage, whether the angioplasty balloon can make certain bends to reach the site of pathology, as well as other limitations.

Summary

[0009] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter.

[0010] One embodiment provides a remote access, tunneling dilator for forming a subcutaneous tract within a human body. The remote access, tunneling dilator may include a tapered body extending from a proximal end to a distal tip with a proximal body section and a straight tapered section disposed proximally-to- distally therebetween, wherein: (1 ) the straight tapered section extends along a straight tapered length having an outer diameter that gradually increases distally- to-proximally from a distal body diameter to a maximum body diameter; and (2) the proximal body section extends along a proximal body length having the maximum body diameter. [0011] Another embodiment provides a continuously tapered dilator for enlarging an internal pathway within a human body. The continuously tapered dilator may include a body extending from a proximal end to a distal tip with at least a proximal body section, a straight tapered section, and a distal end section disposed proximally-to-distally therebetween, wherein the body has a tapered diameter that increases distally-to-proximally from a minimum diameter at the distal end section to a maximum diameter at the proximal body section.

[0012] Yet another embodiment provides a remote access, tunneling dilator for enlarging a subcutaneous tract within a human body. The remote access, tunneling dilator may include a body extending from a proximal end to a distal tip, the body having: (1 ) a tapered outer diameter that increases distally-to-proximally from a minimum diameter at the distal tip to a maximum diameter at the proximal end; (2) a variable material hardness in which the distal tip has a first material hardness, the proximal end has a second material hardness, and the second material hardness is greater than the first material hardness; (3) a plurality of visual indicators disposed upon the body at one or both of a plurality of distally-to- proximally increasing length increments and a plurality of distally-to-proximally increasing diameter increments; and (4) a through hole extending from the proximal end to the distal end, the through hole configured to receive a standard guide wire.

[0013] Other embodiments are also disclosed.

[0014] Additional objects, advantages and novel features of the technology will be set forth in part in the description which follows, and in part will become more apparent to those skilled in the art upon examination of the following, or may be learned from practice of the technology. Brief Description of the Drawings

[0015] Non-limiting and non-exhaustive embodiments of the present invention, including the preferred embodiment, are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. Illustrative embodiments of the invention are illustrated in the drawings, in which:

[0016] FIGURE 1 provides a perspective view of a prior art dilator kit including a catheter, multiple dilators in an increasing spectrum of diameters, and a variety of corresponding sheaths;

[0017] FIGURES 2A-2B provide schematics detailing the veins of the neck and the thoracic and abdominal regions of the human body;

[0018] FIGURES 3A-3D illustrate respective top plan, side, partial, and partial- cross-section views of one embodiment of a remote access, tunneling dilator for the placement of central venous catheters of varying sizes into the jugular veins;

[0019] FIGURES 4A-4B illustrate respective perspective and section views of a distal tip of the dilator of FIGURES 3A-3D;

[0020] FIGURE 5 illustrates a top plan view of another embodiment of a remote access, tunneling dilator for the placement of central venous catheters of varying sizes into the jugular veins;

[0021] FIGURE 6 illustrates a top plan view of another embodiment of a remote access, tunneling dilator for the placement of central venous catheters of varying sizes into the jugular veins;

[0022] FIGURE 7 illustrates a top plan view of another embodiment of a remote access, tunneling dilator for the placement of central venous catheters of varying sizes into the jugular veins;

[0023] FIGURE 8 illustrates a top plan view of another embodiment of a remote access, tunneling dilator for the placement of central venous catheters of varying sizes into the jugular veins; [0024] FIGURE 9 illustrates a top plan view of another embodiment of a remote access, tunneling dilator for the placement of central venous catheters of varying sizes into the jugular veins;

[0025] FIGURE 10 provides a flowchart depicting an exemplary method of using embodiments of the remote access, tunneling dilators of FIGURES 3A-3D, 4A-4B, and 5-9 to remotely place central venous catheters of varying sizes;

[0026] FIGURE 11 illustrates a top plan view of one embodiment of a fascial dilator for forming pathways of varying sizes through subcutaneous soft tissue;

[0027] FIGURE 12 illustrates a top plan view of another embodiment of a fascial dilator for forming pathways of varying sizes through subcutaneous soft tissue;

[0028] FIGURE 13 illustrates a top plan view of another embodiment of a fascial dilator for forming pathways of varying sizes through subcutaneous soft tissue;

[0029] FIGURE 14 illustrates a top plan view of one embodiment of a renal access dilator for forming internal renal access pathways of varying sizes to

accommodate access by urological instruments; and

[0030] FIGURE 15 illustrates a top plan view of another embodiment of a renal access dilator for forming internal renal access pathways of varying sizes to accommodate access by urological instruments.

Detailed Description

[0031] Embodiments are described more fully below in sufficient detail to enable those skilled in the art to practice the system and method. However,

embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense.

[0032] The disclosure discusses systems and methods of use pertaining to dilation systems and related methods of vascular and soft tissue dilation. The systems and methods are for gaining access to portions of a patient's body by a clinician, for example, to place central venous catheters (CVCs) into the jugular veins, to obtain percutaneous access to the kidney by a urologist or a radiologist for approach by urological instruments and for renal percutaneous procedures, for the placement of drainage catheters or gastrostomy feeding tubes, and/or for dilating any strictures and/or obstructions inside the soft tissues or vascular systems of the body.

[0033] In particular, the present invention relates to dilation systems for dilating a tract or pathway opening to a desired size, from very small in diameter (e.g., 5 FR) to very large in diameter (e.g., 30 FR), and maintaining that opening with a single dilator rather than multiple progressive dilators. In this regard, both vascular and soft tissue dilation may be achieved in a manner that is safe and effective, and that enables the most advantageous route through the body without requiring the exchange of multiple dilators that are graduated in diameter size. To aid

explanation, FIGS. 2A-2B schematically illustrate the human anterior thoracic wall and the chest and renal cavities, respectively, for describing placement of central venous catheters (CVCs) into the jugular veins, as well as for describing soft tissue dilation applications including renal access and fascial dilation applications including gastrostomy feeding tubes, abscess drainage, peritoneal drains or external biliary drainage.

I. Vascular Dilation

[0034] Various embodiments of the systems and methods described in this section relate to remote access, tunneling dilators for vascular applications. Some embodiments provide tunneling dilators for the placement of CVCs into the jugular veins, configured for use with a straight or a pre-bent needle and a standard stiff guide wire in creating an access pathway through the skin and a jugular vein such as, for example, the internal jugular vein (IJV) 50 (FIGS 2A-2B). In one

embodiment, the access pathway through the IJV 50 may be made via an approach that is posterior to the sternocleidomastoid muscle (SCM) 52 (FIG. 2k).

[0035] Embodiments of the remote access, soft tissue tunneling dilator provide a number of advantages over existing dilators and provide a safe and effective mechanism for achieving remote access via a single stick, or single incision, placement of a CVC into the I JV 50 using an approach that is posterior to the SCM 52, without the use of a sheath.

[0036] In some embodiments, the remote access, tunneling dilator features a permanent curve configured to navigate subcutaneous curves in the body as the dilator descends through the I JV 50 and enters the left subclavian vein 54 and then the innominate (or brachiocephalic) vein 56 (FIGS. 2A-2B).

[0037] Embodiments of the remote access, tunneling dilator also feature a continuously tapered exterior having a diameter with a progressive French size that eliminates the need for utilizing multiple progressively sized dilators to accommodate different sizes of CVC. Currently, up to ten separate dilators must be progressively exchanged to accommodate the largest catheters (e.g.,

Hemodialysis catheters 14 Fr and Angio-Vac 24 Fr). In addition to excessive time and expense, these dilator exchanges cause bleeding at the puncture site and can increase chances of infection.

[0038] In addition, the continuously tapered configuration allows embodiments of the dilator to be advanced through vascular narrowings, or strictures, without the use of an angioplasty balloon catheter, which saves both procedure time and the added expense of a dilator balloon kit. Because the continuous taper enables embodiments of the remote access, tunneling dilator to be advanced through vascular strictures, the clinician may gain access through a vein that would otherwise be unavailable, thereby forcing clinician to choose a less advantageous route. Embodiments of the tapered dilator allow easy treatment of and therapeutic access through these strictures. This reduces procedural time and also allows treatment of some conditions which were not previously considered for minimally invasive surgical techniques.

[0039] Additional embodiments of the tunneling dilator disclosed herein feature a varying material hardness (shore durometer) over a length of the dilator. That is, a distal section of the dilator may be formed from a softer material, allowing the dilator to be more easily maneuvered as it progresses around and posterior to the SCM 52 or other subcutaneous curves without risk of material folding that may kink the guide wire.

[0040] Embodiments of the remote-access, tunneling dilator may also feature visual indicators marking the dilator diameter and/or the dilator length at defined increments along the dilator body, providing a convenient mechanism by which a clinician may gauge the diameter of the tract being formed within the body and/or the requisite length of the catheter necessary to reach a target position within the body.

[0041] Turning to exemplary embodiments, FIGS. 3A-3D illustrate respective top plan, side, partial, and partial cross-sectional views of one embodiment of a remote access, curved tunneling dilator 100 for use in placing CVCs into the jugular veins. In this embodiment, the curved dilator 100 has a total length, LA, of 43.5 cm separated into five zones extending between Markers A0-A1 , A1 -A2, A2-A3, A3-A4, and A4-A5, including a dilator body 102 having a distal end section 104 extending 4cm from a distal tip 106 at Marker Ao to Marker Ai, a curved section 108 extending 6 cm from Markers A1 -A2, a straight tapered section 110 extending 24 cm between Markers A2-A3, and a proximal body section 112 extending 7 cm between Markers A3-A4. In this embodiment, the dilator 100 further includes a connector end section 114 disposed adjacent to a proximal end 116 of the dilator body 102, extending 2.5 cm from Marker A ₄ to a terminal proximal end of the dilator 100 at Marker As.

[0042] In one embodiment, a longitudinal through hole 118 may extend through an entirety of the length, LA, of the dilator 100. The longitudinal through hole 118 may have an inner diameter, d _A , configured to accommodate a standard guide wire (e.g., .035 inch diameter, .038 inch diameter) (not shown). In addition, the dilator body 102 may include a hydrophilic outer coating 121 over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues. [0043] In this embodiment, the body 102 of the dilator 100 may form a permanent curve or angle in the curved section 108 extending between Markers A1 -A2, as shown in FIG. 3A. In this embodiment, the permanent curve may form a body angle, BA _A , of approximately 40 degrees relative to the straight tapered section 110 extending between Markers A2-A3. Notably, the permanent curve, or body angle, BA _A , may form any appropriate angle including, for example, an angle of 5 degrees, 45 degrees, or 90 degrees, depending on the intended dilation

application.

[0044] The permanent curve enables embodiments of the dilator 100 to better navigate subcutaneous curves and bodily features to establish remote access via the jugular veins. This is most pronounced when establishing remote access via the left IJV 50 (FIG. 2A), as is necessary in about 10% of CVC placements. A posterior-lateral approach to the left IJV 50 involves the dilator navigating two curves as the dilator descends from the IJV 50 and enters the left subclavian vein 54, and then the innominate/brachiocephalic vein 56 (FIGS. 2A-2B). Due to the difficulty of navigating these curves, the traditional approach uses a non-curved sheath, which may lead to venous perforation and catastrophic consequences.

[0045] In addition to the permanent curve or body angle, BA _A , the body 102 of the dilator 100 may feature a tapered configuration having a tapered outer diameter, DA, that progresses in diameter size distally-to-proximally from the distal tip 106 to the proximal end 116 of the body 102, beginning, in this embodiment, with an outer diameter of 5 FR on the French catheter scale at the distal end section 104 extending between Markers A0-A1, increasing to 6 FR through the curved section 108 extending between Markers A1-A2, then progressively increasing by 1 FR every 3 cm through the straight tapered section 110 from 6 FR to 14 FR between Markers A2-A3, reaching and maintaining a maximum diameter of 14 FR at the proximal body section 112 extending between Markers A3-A4, as detailed in FIGS. 3A-3B. In some embodiments, the distal tip 106 of the dilator body 102 may additionally be tapered by a tip angle, TA, of approximately 5 degrees, as shown in FIGS. 3C-3D, for additional ease of insertion and

manipulation.

[0046] Visual indicators 120 may be disposed upon the body 102 of the dilator 100 at each increasing diameter progression to enable a clinician to determine the outer diameter size entering the body, and, in turn, the size of the remote access pathway that will be created by the dilator 100. Additionally or alternatively, the visual indicators 120 may be disposed on the body at defined length increments along the total length, LA, of the dilator 100, enabling the clinician to quickly determine the length of CVC necessary for the particular application based upon the visual indicator 120 aligned at the entry point on the patient’s skin when the distal tip 106 of the dilator 100 reaches its subcutaneous target within the patient’s body (e.g., within the superior vena cava (SVC) 58 right above the heart). In the prior art, this CVC length determination is made by marking the guide wire when its distal end is seen at the ideal location in the SVC. The guide wire is then removed to measure its length before reinserting the guide wire, extracting the final (i.e., largest) dilator from the body, and placing the CVC. This method requires an extra step and introduces error into the length determination. The visual indicators 120 (e.g., stripes or tick marks) may be pad printed or laser marked on the outer (i.e., curved) side of the dilator body to maximize

radiological/fluoroscopic visibility of the indicators 120 for use in directing the dilator 100 through the body during a procedure.

[0047] As discussed above, the progressively increasing outer diameter, DA, of the dilator body 102 renders the dilator 100 suitable for the placement of a variety of catheter sizes. Rather than exchanging discrete dilators of increasing diameter and confronting the associated risks discussed above, the clinician may use a long guide wire along with a single remote access, curved tunneling dilator 100 having the progressive French sizing for a posterior approach through, for example, the IJV 50, to the superior vena cava 58, and on to the inferior vena cava 60 (FIGS. 2A-2B). [0048] In one embodiment, the body 102 of the remote access, curved tunneling dilator 100 may also feature a variable material hardness. In this embodiment, the material of the body may increase in material hardness or Shore durometer rating from the distal tip 106 at Marker Ao toward the proximal end 116 of the body 102 at Marker A ₄ . For example, the distal end section 104 extending between Markers A0-A1 may be formed of the softest, least resistant material having a hardness of Shore 25D, forming a soft dilator tip. The curved or angled section 108 between Markers A1 -A2 may increase in hardness to a hardness of Shore 50D. Progressing distally-to-proximally, the straight tapered section 110 extending between Markers A2-A3 and the proximal body section 112 extending between Markers A3-A4 may each have a hardness of Shore 60D.

[0049] The soft dilator tip, or the distal end section 104, enables flex in the dilator tip as it traverses bodily tissues. This prevents both kinking of the guide wire and puncturing of the venous sidewalls as the remote access, tunneling dilator 100 navigates curves within the body. Notably, the increasing material hardness or Shore durometer ratings of the dilator body 102 may vary as appropriate to accommodate the intended use of the dilator 100. For example, varying curves in the body, discussed above, may result in different hardness ratings along the length of the dilator body 102 to ensure structural integrity of the dilator.

[0050] The connector end section 114 of the dilator 100 may comprise a hub 122 such as, for example, a standard female tapered Luer lock hub formed of polycarbonate, as detailed in FIGS. 4A-4B, to allow attachment of other Luer fitting devices to the dilator 100 for use in, for example, the injection of contrast dye. In some embodiments, the longitudinal through hole 118 through the dilator body 102 may be tapered outward at the proximal end 116 of the body 102 to provide a lead-in from the hub 122 to the body 102 for the guide wire.

[0051] FIG. 5 illustrates a side view of another exemplary embodiment of a remote access, curved tunneling dilator 200 for use in placing CVCs into the jugular veins. The dilator 200 may have similar configuration to the dilator 100, with differing length and taper dimensions and material hardness variations. In this

embodiment, the curved dilator 200 has a total length, LB, of 35 cm separated into five zones extending between Markers B0-B1 , B1-B2, B2-B3, B3-B4, and B4-B5, including a dilator body 202 having a distal end section 204 extending 4cm from a distal tip 206 at Marker Bo to Marker Bi, a curved section 208 extending 6 cm from Markers B1-B2, a straight tapered section 210 extending 14 cm between Markers B2-B3, and a proximal body section 212 extending 10 cm between Markers B3-B4. The dilator 200 further includes a connector end section 214 disposed adjacent to a proximal end 216 of the dilator body 202, extending 1 cm from Marker B ₄ to a terminal proximal end of the dilator 200 at Marker B5. The connector end section 214 may comprise a 1 cm hub 222 such as, for example, a standard female tapered Luer lock hub to allow attachment of other Luer fitting devices to the dilator 100 for the injection of contrast dye.

[0052] In one embodiment, a longitudinal through hole 218 may extend through an entirety of the length, LB, of the dilator 200. The longitudinal through hole 218 may have an inner diameter, d _B , configured to accommodate a standard guide wire (e.g., .035 inch diameter, .038 inch diameter) (not shown). In addition, the dilator body 202 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0053] In this embodiment, the body 202 of the dilator 200 may form a permanent curve or angle in the curved section 208 extending between Markers B ₁ -B ₂ . In this embodiment, the permanent curve may form a body angle, BA _B , between 40-80 degrees relative to the straight tapered section 210 extending between Markers B ₂ -B3. Notably, in some embodiments, the permanent curve, or body angle, BA _B , may form any appropriate angle including for example, an angle of 5 degrees, 45 degrees, or 90 degrees, depending on the intended dilation application.

[0054] In addition to the permanent curve or body angle, BA _B , the body 202 of the dilator 200 may feature a tapered configuration having a tapered outer diameter, DB, that progresses in diameter size distally-to-proximally from the distal tip 206 to the proximal end 216 of the body 202, beginning, in this embodiment, with an outer diameter of 5 FR at the distal end section 204 extending between Markers B0-B1 , increasing to 6 FR through the curved section 108 extending between Markers B1-B2, then progressively increasing by 1 FR every 2 cm through the straight tapered section 210 from 7 FR to 14 FR between Markers B2- B3, reaching and maintaining a maximum diameter of 14 FR at the proximal body section 212 extending between Markers B3-B4. In some embodiments, the distal tip 206 of the dilator body 202 may additionally be tapered by approximately 5 degrees, in a manner that renders the tip rounded rather than blunt, for additional ease of insertion and manipulation.

[0055] Visual indicators 220 may be disposed upon the body 202 of the dilator 200 at each increasing diameter progression to enable a clinician to determine the outer diameter size entering the body, and, in turn, the size of the remote access pathway that will be created by the dilator 200. Additionally or alternatively, the visual indicators 220 may be disposed on the body at defined length increments along the total length, LB, of the dilator 200, enabling the clinician to quickly determine the length of CVC necessary for the particular application based upon the visual indicator 220 aligned with an entry point on the patient’s skin when the distal tip 206 of the dilator 200 reaches its subcutaneous target within the patient’s body.

[0056] In one embodiment, the body 202 of the remote access, curved tunneling dilator 200 may also feature a variable material hardness along the length of the body, LB. For example, in one embodiment the entire 35 cm length, LB, of the body 202 may have a material hardness or Shore durometer rating of 65D.

Alternatively, the material of the body 202 may increase in hardness to Shore 80D-90D within the 14 cm straight tapered section 210 between Markers B2-B3.

[0057] Additional embodiments of the dilator 200 may vary in section length, taper, and material hardness as desired and/or appropriate. For example, in one embodiment, the tapered section 210 may extend 7 cm between Markers B2-B3 for a total length, LB, of 28 cm, while distally-to-proximally increasing in diameter by 1 FR every 1 cm from 7 FR to 14 FR, reaching the maximum diameter of 14 FR at Marker B3. In this configuration, the entire 28 cm length, LB, of the body 202 may have a hardness of shore 65D, or alternatively, the material of the body 202 may increase in hardness to Shore 80D-90D within the 7 cm straight tapered section 210 between Markers B2-B3. In each embodiment, however, the hardness may return or remain Shore 65D in the proximal body section 212 between Markers B3-B4 to provide stability at the maximum diameter.

[0058] FIGS. 6-9 illustrate side views of various straight, remote access, vascular dilators, each having a different overall length and taper angle. Specifically, FIG. 6 illustrates a side view of one embodiment of a remote access, straight tunneling dilator 300 for use in placing CVCs into the jugular veins. In this embodiment, the straight dilator 300 is shown broken down into 3 zones extending between

Markers C0-C1 , C1 -C2, and C2-C3 for a total length, Lc, of 29 cm, including a dilator body 302 having a tapered section 310 extending 18 cm from a rounded distal tip 306 at Marker Co to Marker Ci and a proximal body section 312 extending 10 cm between Markers C1 -C2. The dilator 300 further includes a connector end section 314 disposed adjacent to a proximal end 316 of the dilator body 302, extending 1 cm from Marker C2 to a terminal proximal end of the dilator 300 at Marker C3. The connector end section 314 of the dilator 300 may comprise a hub 322 such as, for example, a standard female tapered Luer lock hub to allow attachment of other Luer fitting devices to the dilator 300 for the purpose of, for example, injecting contrast dye.

[0059] In one embodiment, a longitudinal through hole 318 may extend through an entirety of the length of the dilator 300. The longitudinal through hole 318 may have an inner diameter, dc, configured to accommodate a standard guide wire (e.g., .035 inch diameter) (not shown). In addition, the dilator body 302 may include a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues. [0060] In this embodiment, the body 302 of the dilator 300 may feature a tapered configuration having a tapered outer diameter, Dc, that progresses in diameter size distally-to-proximally from the distal tip 306 to the proximal end 316 of the body 302, beginning, in this embodiment, with an outer diameter of 5 FR at the distal tip 306, then progressively increasing through the straight tapered section 310 by 1 FR every 2 cm, from 5 FR to 14 FR, between Markers C0-C1, and reaching and maintaining a maximum diameter of 14 FR at the non-tapered proximal body section 312 extending between Markers C1-C2, as detailed in FIG. 6.

[0061] Visual indicators 320 may be disposed upon the body 302 of the dilator 300 at each increasing diameter progression to enable a clinician to determine the outer diameter size entering the body, and, in turn, the size of the remote access pathway that will be created by the dilator 300. Additionally or alternatively, the visual indicators 320 may be disposed on the body 302 at defined length increments along the total length, Lc, of the dilator 300, enabling the clinician to quickly determine the length of CVC necessary for the particular application based upon the visual indicator 320 aligned at the entry point when the distal tip 306 of the dilator 300 reaches its subcutaneous target within the patient’s body. The visual indicators 320 (e.g., stripes or tick marks) may be pad printed or laser marked on the outer side of the dilator body to maximize radiological/fluoroscopic visibility of the indicators 320 for use in directing the dilator 300 through the body during a procedure. In addition, the dilator body 302 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0062] FIGS. 7-9 illustrate side views of additional exemplary straight, remote access, vascular dilators 400, 500, and 600. Each of the dilators 400, 500, 600 may be similar in configuration to dilator 300 and includes the same sections and components, discussed above, with varying section lengths and taper slopes to meet the needs of different vascular dilation applications (e.g., pathway lengths, pathway configurations, patient sizes). More specifically and in one embodiment, dilator 400 of FIG. 7 may have a total length, LD, of 20 cm extending between a rounded or angled distal tip 406 and a proximal end of a hub 422. A body 402 of the dilator 400 may feature a tapered configuration having a tapered outer diameter, DD, that progresses in diameter size distally-to-proximally from the distal tip 406 to a proximal end 416 of the body 402, beginning, in this embodiment, with an outer diameter of 5 FR at the distal tip 406 and progressively increasing through a 9 cm straight tapered section 410 by 1 FR every 1 cm, from 5 FR to 14 FR, between Markers D0-D1 , reaching and maintaining a maximum diameter of 14 FR through a 10 cm proximal body section 412 extending between Markers D1-D2. The dilator 400 further includes a connector end section 414 disposed adjacent to the proximal end 416 of the dilator body 402, extending 1 cm from Marker D2 to a terminal proximal end of the dilator 400 at Marker D3. The dilator 400 may include a through hole 418 having a diameter, dp, configured to accommodate a standard guide wire (e.g., .035 inch) and may include sets of visual indicators 420 disposed at predetermined and progressive length and/or diameter increments along the body 402 to assist the clinician in determining a depth and/or diameter of the resulting tract or passageway formed within the patient’s body. In addition, the dilator body 402 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0063] Dilator 500, shown in FIG. 8, may have a total length, LE, of 45 cm extending between a rounded or angled distal tip 506 and a proximal end of a hub 522. A body 502 of the dilator 500 may feature a tapered configuration having a tapered outer diameter, DE, that progresses in diameter size distally-to-proximally from the distal tip 506 to a proximal end 516 of the body 502, beginning, in this embodiment, with an outer diameter of 5 FR at the distal tip 506 and progressively increasing through a 38 cm straight tapered section 510 by 1 FR every 2 cm, from 5 FR to 24 FR, between Markers E0-E1, reaching and maintaining a maximum diameter of 24 FR at a 6 cm non-tapered proximal body section 512 extending between Markers E1 -E2. The dilator 500 may further include a connector end section 514 disposed adjacent to the proximal end 516 of the dilator body 502, extending 1 cm from Marker E2 to a terminal proximal end of the dilator 500 at Marker E3. The dilator 500 may include a through hole 518 configured to accommodate a standard guide wire (e.g., .038 inch) and may include sets of visual indicators 520 disposed at predetermined and progressive length and/or diameter increments along the body 402 to assist the clinician in determining a depth and/or diameter of the resulting tract or passageway formed within the patient’s body. In addition, the dilator body 502 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0064] Dilator 600, shown in FIG. 9, may have a total length, LF, of 25 cm extending between a rounded or angled distal tip 606 and a proximal end of a hub 622. A body 602 of the dilator 600 may feature a tapered configuration having a tapered outer diameter, DF, that progresses in diameter size distally-to-proximally from the distal tip 606 to a proximal end 616 of the body 602, beginning, in this embodiment, with an outer diameter of 5 FR at the distal tip 606 and progressively increasing through a 19 cm straight tapered section 610 by 1 FR every 1 cm, from 5 FR to 24 FR, between Markers F0-F1, reaching and maintaining a maximum diameter of 24 FR through a 5 cm non-tapered proximal body section 612 extending between Markers F1-F2. The dilator 600 may further include a connector end section 614 disposed adjacent to the proximal end 616 of the dilator body 602, extending 1 cm from Marker F2 to a terminal proximal end of the dilator 600 at Marker F3. The dilator 600 may also include a through hole 618 configured to accommodate a standard guide wire (e.g., .038 inch) and may include sets of visual indicators 620 disposed at predetermined and progressive length and/or diameter increments along the body 602 to assist the clinician in determining a depth and/or diameter of the resulting tract or passageway formed within the patient’s body. In addition, the dilator body 602 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0065] A standard micropuncture kit, along with embodiments of the remote access, tunneling dilator 100, 200, 300, 400, 500, 600, discussed above in relation to FIGS. 3-9, may enable a method of remotely placing a CVC via a jugular vein such as the IJV 50 from an approach that is posterior to the SCM 52 (FIGS. 2A- 2B). FIG. 10 provides a flowchart depicting an exemplary method of using embodiments of the remote access, tunneling dilator 100, 200, 300, 400, 500, 600 to remotely place a CVC. In one embodiment, the method (700) may initiate with puncturing the IJV 50 from a remote infraclavicular access point posterior to the SCM 52 (702) using a straight or pre-bent micropuncture needle and ultrasonic guidance. Once placement of the tip of the needle is confirmed by ultrasound to be within the IJV 50, the clinician may advance a microwire through the neck into the SVC 58 (704) before advancing a 4 FR diameter dilator from the

micropuncture kit over the microwire (706) and withdrawing the microwire. Next, a standard guide wire (e.g., .035 inch guide wire, .038 inch guide wire) may be advanced through the 4 FR dilator (708) and the 4 FR dilator may be withdrawn (710) prior to beginning the process of vascular dilation. Holding the guide wire, an embodiment of the remote access, soft tissue tunneling dilator 100, 200, 300, 400, 500, 600 may be advanced over the guide wire and through the soft tissues, thereby using a single dilator to dilate the tissue around the guide wire and to dilate the IJV to facilitate catheterization (712). Once dilation is complete, the dilator 100, 200, 300, 400, 500, 600 may be withdrawn (714), and the CVC may be placed over the guide wire and advanced through the tunneled access pathway created by the dilator 100, 200, 300, 400, 500, 600 into the blood vessel (716). The guide wire may then be withdrawn, leaving the CVC in the blood vessel (718).

[0066] In one embodiment, the disclosed dilator may be provided as part of a kit including the remote access, tunneling dilator 100, 200, 300, 400, 500, 600 and the micropuncture system discussed above, including the straight or pre-bent needle, the syringe, the 4 FR dilator, the guide wire, and the CVC.

[0067] The dilator and methods of use described above may be used for single stick, tunneled CVC placement into any appropriate vein from any appropriate approach. Embodiments may be particularly advantageous for remote access via the IJV from an approach that is posterior to the SCM. Use of embodiments of the remote access, soft tissue tunneling dilator and associated methods discussed above provides a number of benefits over existing CVC placement mechanisms, including: (1 ) Providing for patient choice: Patients given a choice of the standard two-stick system or the Single stick system unanimously choose the single stick. A single stick, posterior approach allows the patient to more freely turn his or her head without pain, and any residual cosmetic scar is not on the patient’s neck; (2) More accessibility: Emergency room personnel may have placed a cervical collar on the patient so traditional two-stick access is not available. Additionally, the traditional two-stick site may not be available because of skin burns or skin damaged by radiation therapy or lymphadenopathy; (3) Fewer Patient

Complications: Patients do not have to hold their breath during the single-stick procedure using embodiments of the disclosed dilator. Many patients requiring catheters are in respiratory distress. The lateral/posterior approach avoids causing pneumothorax and cardiac tamponade. Further, a one-stick procedure reduces the chance of air embolism that happens occasionally with the two-stick

procedure. There is also less bleeding because the tapered configuration of the remote access, tunneling dilator eliminates the need to exchange progressively sized dilators to accommodate larger catheters, and there is less risk of infection because access to the vein is further away from the lateral/posterior puncture site. It also eliminates the need for peel away sheaths. In addition, access using the disclosed remote access, tunneling dilator 100, 200, 300, 400, 500, 600 requires less time to perform the procedure because it is accomplished using a single tapered dilator, rather than numerous exchanged dilators that increase in diameter, because dilation may occur without the time and expense of an angioplasty balloon catheter for advancement through vascular strictures, and because the visual indicators disposed upon the dilator allow for easy

measurement/assessment of the catheter length necessary to reach the target point within the body.

II. Soft Tissue Dilation

[0068] In addition to the placement of CVCs as described above, embodiments of the remote access, soft tissue tunneling dilator may be implemented in a variety of percutaneous/subcutaneous tunneling procedures including, for example, accessing the kidneys for placement of a peritoneal drainage catheter, for providing access for urological instruments, and/or for placing drainage catheters or gastrostomy feeding tubes. Rather than advancing multiple progressively larger dilators through the body, the disclosed dilators are useful in establishing remote access due to their ability to safely and effectively navigate subcutaneous features in the body, and to dilate internal passageways to achieve large subcutaneous tracts with a single dilator, enabling dilation procedures to be accomplished more quickly, at less expense, and for the patient to experience significantly less pain.

[0069] FIG. 11 illustrates a side view of one embodiment of a remote access, tunneling facial dilator 800. Fascial dilators are used in many medical procedures, ranging from simple vascular access to major cardiac surgery, and by many physicians across all specialties. Example procedures include vascular dilation to allow various therapies and soft tissue dilation to allow access to internal organs or vessels, including but not limited to gastrostomy tubes, abscess drains, peritoneal or pleural drains, and hemodialysis catheters. Currently such dilation involves utilizing multiple dilators, progressing in size until the final tract is large enough for the permanent or usable catheter. This process requires multiple steps to establish the correct size tract. Embodiments of continuously tapered fascial dilator discussed herein will allow these techniques and procedures to be performed in a single step with a single dilator, saving time and money as well as reducing complications.

[0070] As shown in FIG. 11 and in one embodiment, the dilator 800 may have a similar configuration to the dilators 100-600 discussed above, with differing sections, lengths, taper dimensions, and material hardness variations. In this embodiment, the curved fascial dilator 800 may have a total length, LG, of 41 cm separated into four zones extending between Markers G0-G1 , G1 -G2, G2-G3, and G3-G4, including a dilator body 802 having a distal end section 804 extending 9 cm from a tapered distal tip 806 at Marker Go to Marker Gi, a straight tapered section 810 extending 24 cm between Markers G1-G2, and a proximal body section 812 extending 7 cm between Markers G2-G3. The dilator 800 further includes a connector end section 814 disposed adjacent to a proximal end 816 of the dilator body 802, extending 1 cm from Marker G3 to a terminal proximal end of the dilator 800 at Marker G4. The connector end section 814 may comprise a 1 cm hub 822 such as, for example, a standard female tapered Luer lock hub to allow attachment of other Luer fitting devices to the dilator 800 for the injection of contrast dye.

[0071] In this embodiment, the body 802 of the dilator 800 may form a permanent curve between the distal end section 804 extending between Markers G0-G1 and the straight tapered section 810 extending between Markers G1-G2. In this embodiment, the permanent curve may form a body angle, BAG, between 30-80 degrees relative to the straight tapered section 810. Notably, in some

embodiments, the permanent curve or body angle, BAG, may form any

appropriate angle including for example, an angle of 5 degrees, 45 degrees, or 90 degrees, depending on the intended fascial dilation application.

[0072] In addition to the permanent curve or body angle, BAG, the body 802 of the dilator 800 may feature a tapered configuration having a tapered outer diameter, DG, that progresses in diameter size distally-to-proximally from the distal tip 806 to the proximal end 816 of the body 802, beginning, in this embodiment, with an outer diameter of 5 FR at the distal tip 806 at the Marker Go and

increasing by 1 FR every 1 cm through the distal end section 804, from 5 FR to 14 FR between Markers G0-G1, then progressively increasing by 1 FR every 3 cm through the straight tapered section 810 from 14 FR to 22 FR between Markers G1-G2, and reaching and maintaining a maximum diameter of 22 FR at the proximal body section 812 extending between Markers G2-G3. In some

embodiments, the distal tip 806 of the dilator body 802 may additionally be tapered by approximately 5 degrees, in a manner that renders the tip rounded rather than blunt, for additional ease of insertion and manipulation.

[0073] In one embodiment, a longitudinal through hole 818 may extend through an entirety of the length of the dilator 800. The longitudinal through hole 818 may have an inner diameter, dG, configured to accommodate a standard guide wire (e.g., .038 inch diameter) (not shown). In addition, the dilator body 802 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0074] Visual indicators 820 may be disposed upon the body 802 of the dilator 800 at each increasing diameter progression to enable a clinician to determine the outer diameter size entering the body, and, in turn, the size/width of the remote access pathway that will be created by the dilator 800. Additionally or alternatively, the visual indicators 820 may be disposed on the body at defined length

increments along the total length, LG, of the dilator 800, enabling the clinician to quickly determine the length of CVC necessary for the particular application based upon the visual indicator 820 aligned with an insertion point the patient’s skin when the distal tip 806 of the dilator 800 reaches its subcutaneous target within the patient’s body.

[0075] In one embodiment, the body 802 of the remote access, tunneling fascial dilator 800 may also feature a variable material hardness along the length of the body, LG. For example, in this embodiment, the body 802 may have a material hardness or Shore durometer rating of 80D-90D within the distal end section 804 where the diameter ranges from 7 FR to 12 FR, while the remainder of the dilator body 802 may be 65D. This variation enables the dilator to tunnel through tougher tissue oftentimes encountered by fascial dilators. Additional embodiments of the dilator 800 may vary in section length, taper, and material hardness as desired and/or appropriate.

[0076] FIGS. 12-13 illustrate side views of two additional straight, remote access, fascial dilators, each having a different overall length and taper angle. Specifically, FIG. 12 illustrates a side view of one embodiment of a remote access, straight tunneling dilator 900 for use in fascial dilation applications. In this embodiment, the straight dilator 900 is shown broken down into 3 zones extending between Markers H0-H1 , H1 -H2, and Fh-F for a total length, L _H , of 39 cm, including a dilator body 902 having a tapered section 910 extending 32 cm from a rounded distal tip 906 at Marker Ho to Marker Hi and a proximal body section 912 extending 6 cm between Markers H1 -H2. The dilator 900 further includes a connector end section 914 disposed adjacent to a proximal end 916 of the dilator body 902, extending 1 cm from Marker H2 to a terminal proximal end of the dilator 900 at Marker H3. The connector end section 914 of the dilator 900 may comprise a hub 922 such as, for example, a standard female tapered Luer lock hub to allow attachment of other Luer fitting devices to the dilator 900 for the purpose of, for example, injecting contrast dye.

[0077] In one embodiment, a longitudinal through hole 918 may extend through an entirety of the length of the dilator 900. The longitudinal through hole 918 may have an inner diameter, d _hi , configured to accommodate a standard guide wire (e.g., .038 inch diameter) (not shown). In addition, the dilator body 902 may include a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0078] In this embodiment, the body 902 of the dilator 900 may feature a tapered configuration having a tapered outer diameter, DH, that progresses in diameter size distally-to-proximally from the distal tip 906 to the proximal end 916 of the body 902, beginning, in this embodiment, with an outer diameter of 6 FR at the distal tip 906, then progressively increasing through the straight tapered section 910 by 1 FR every 2cm, from 6 FR to 22 FR, between Markers H0-H1, and reaching and maintaining a maximum diameter of 22 FR at the non-tapered proximal body section 912 extending between Markers H1-H2, as detailed in FIG. 12.

[0079] Visual indicators 920 may be disposed upon the body 902 of the dilator 900 at each increasing diameter progression to enable a clinician to determine the outer diameter size entering the body, and, in turn, the size of the remote access pathway that will be created by the dilator 900. Additionally or alternatively, the visual indicators 920 may be disposed on the body at defined length increments along the total length, LH, of the dilator 900, enabling the clinician to quickly determine the length of catheter necessary for the particular application based upon the visual indicator 920 aligned at the entry point when the distal tip 906 of the dilator 900 reaches its subcutaneous target within the patient’s body.

[0080] FIG. 13 illustrates a side view of one embodiment of another exemplary straight, remote access, facial dilator 1000. Dilator 1000 may be similar in configuration to dilator 900 and includes the same sections and components, discussed above, with varying section lengths and taper slopes to meet the needs of different fascial dilation applications (e.g., pathway lengths, patient sizes, tissue types to be dilated). More specifically and in one embodiment, dilator 1000 of FIG. 13 may have a total length, U, of 22 cm extending between a rounded or angled distal tip 1006 and a proximal end of a hub 1022. A body 1002 of the dilator 1000 may feature a tapered configuration having a tapered outer diameter, Di, that progresses in diameter size distally-to-proximally from the distal tip 1006 to a proximal end 1016 of the body 1002, beginning, in this embodiment, with an outer diameter of 6 FR at the distal tip 1006 and progressively increasing through a 16 cm straight tapered section 1010 by 1 FR every 1 cm, from 6 FR to 22 FR, between Markers I0-I1, reaching and maintaining a maximum diameter of 22 FR through a 5 cm non-tapered proximal body section 1012 extending between Markers I1-I2. The dilator 1000 further includes a connector end section 1014 disposed adjacent to the proximal end 1016 of the dilator body 1002, extending 1 cm from Marker I2 to a terminal proximal end of the dilator 1000 at Marker I3. The connector end section 1014 may comprise a hub 1022 such as, for example, a standard female tapered Luer lock hub to allow attachment of other Luer fitting devices to the dilator 1000 for the purpose of, for example, injecting contrast dye.

[0081]The dilator 1000 may include a through hole 1018 configured to

accommodate a standard guide wire (e.g., .038 inch) and may include sets of visual indicators 1020 disposed at predetermined and progressive length and/or diameter increments along the body 1002 to assist the clinician in determining a depth and/or diameter of the resulting tract or passageway formed within the patient’s body. In addition, the dilator body 1002 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0082] FIG. 14 illustrates a side view of one embodiment of a remote access, tapered renal access dilator 1100 for use in achieving pathways of varying sizes (e.g., from 6 FR up to 30 FR) for renal access for urological instruments. Renal dilation is often used for placement of tubes into the collecting system of the kidneys for drainage purposes or for access for percutaneous kidney stone removal of large "staghorn" type stones. Currently to achieve placement of these tubes, from 8 FR up to 30 FR, access to the kidney is obtained initially with a 4 FR access dilator, and a wire is placed using fluoroscopic guidance into the collecting system. After initial access, a series of dilators, from 6 FR to 24 FR or more, are used to gradually increase the size of the tract. Use of a single continuously tapered dilator offers the advantage of having one step and thus reducing procedural time and potential complications.

[0083] In this embodiment, the renal access dilator 1100 is shown broken down into two zones extending between Markers J0-J1 and J1-J2 for a total length, U, of 42 cm, including a dilator body 1102 having a tapered section 1110 extending 32 cm from a pointed distal tip 1106 at Marker Jo to Marker Ji and a proximal body section 1112 extending 10 cm between Markers J1-J2. The dilator 1100 may exclude a connector end section and hub, as a hub is unnecessary without the need to inject contrast dye.

[0084] In this embodiment, the body 1102 of the dilator 1100 may feature a tapered configuration having a tapered outer diameter, Dj, that progresses in diameter size distally-to-proximally from the distal tip 1106 to the proximal end 1116 of the body 1102, beginning, in this embodiment, with an outer diameter of 6 FR at the distal tip 1106, then progressively increasing through the straight tapered section 1110 by 1 FR every 2cm, from 6 FR to 22 FR, between Markers J0-J1, and reaching and maintaining a maximum diameter of 22 FR through the non-tapered proximal body section 1112 extending between Markers J1-J2, as detailed in FIG. 14.

[0085] In one embodiment, a longitudinal through hole 1118 may extend through an entirety of the length of the dilator 1100. The longitudinal through hole 1118 may have an inner diameter, dj, configured to accommodate a standard guide wire (e.g., .038 inch diameter) (not shown).

[0086] Visual indicators 1120 may be disposed at predetermined and progressive length and/or diameter increments along the body 1102 to assist the clinician in determining a depth and/or diameter of the resulting tract or passageway formed within the patient’s body. In addition, the dilator body 1102 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0087] FIG. 15 illustrates a cross-sectional view of an additional exemplary renal access dilator 1200, which is similar in configuration to dilator 1100, discussed above, and includes the same sections and components with varying section lengths and taper slopes to meet the needs of different renal access dilation applications (e.g., pathway lengths, sizes of patients, tissue type). More specifically and in this embodiment, the dilator 1200 may have a total length, LK, of 44 cm extending between a pointed distal tip 1206 and a proximal end 1216. A body 1202 of the dilator 1200 may feature a tapered configuration having a tapered outer diameter, DK, that progresses in diameter size distally-to-proximally from the distal tip 1206 to the proximal end 1216 of the body 1202, beginning, in this embodiment, with an outer diameter of 6 FR at the distal tip 1206 and progressively increasing through a 24 cm straight tapered section 1210 by 1 FR every 1 cm, from 6 FR to 30 FR, between Markers K0-K1, reaching and

maintaining a maximum diameter of 30 FR through a 20 cm non-tapered proximal body section 1212 extending between Markers K1-K2.

[0088] The dilator 1200 may include a through hole 1218 configured to

accommodate a standard guide wire (e.g., .038 inch) and may include sets of visual indicators (not shown) disposed at predetermined and progressive length and/or diameter increments along the body 1202 to assist the clinician in determining a depth and/or diameter of the resulting tract or passageway formed within the patient’s body. In addition, the dilator body 1202 may feature a hydrophilic outer coating over an entirety of its length for added lubricity to more easily slip through subcutaneous tissues.

[0089] In some embodiments, the renal access dilator 1200 may be used in conjunction with a sheath 1224, as shown in FIG. 15. Once the subcutaneous tract is dilated to the desired size, the sheath 1224 may be inserted into the tract over the dilator to maintain the tract opening before the dilator 1200 is removed. In this embodiment, the sheath may have a length, Ls, of 16 cm and include a through hole 1226 having a diameter configured to slide over the maximum diameter of the dilator 1200.

[0090] In some embodiments, the dimensions and the taper slopes of the straight tapered section 1210 and the proximal body section 1212 of the dilator 1200 may vary as appropriate for differing, namely smaller or shorter, intended tract sizes and lengths. For example, the straight tapered section 1210 may progressively increase through 18, 20, or 22 cm by 1 FR every 1 cm, from 6 FR to 24 FR, from 6 FR to 26 FR, and from 6 FR to 28 FR, respectively, between Markers K0-K1. The 18, 20, or 22 cm straight tapered section 1210 may combine with the 20 cm proximal body section 1212 for a total length of 38, 40, or 42 cm. Embodiments of the sheath 1224 may, in turn, be configured to slide about or over the respective maximum diameter of the dilator 1200. In this regard, embodiments of the renal access dilator 1200 may provide a dilated renal access tract or pathway having an extremely large diameter range beginning a 6 FR and increasing to 24 FR, 26 FR, 28 FR, and finally 30 FR using a single dilator.

[0091] Embodiments of the remote access, tunneling dilator 100-1200 discussed herein provide exemplary configurations only. Additional embodiments may have any appropriate length, diameter, curvature, and/or material hardness variance, and may include any appropriate degree or slope of tapering, or any appropriate progressive stepping in outer diameter French catheter sizes. For example and as described above, dilator embodiments may feature a long length with only a few increasing increments in French catheter size for access through the left IJV 50. Other embodiments of the dilator may feature a shorter length with only a few increasing increments in French catheter size for the right IJV. Still other embodiments may feature a thinner body made for pediatric patients. Other embodiments may be configured in length, taper, and maximum diameter for soft tissue applications such as fascial and renal access applications to achieve a very large tract size with a single dilator, as discussed above. Embodiments of the dilator and/or the accompanying pre-bent or straight needle may feature ultra- visible tips for better visualization under ultrasound guidance.

[0092] Embodiments of the remote access, tunneling dilator 100-1200 may be formed of any appropriate material to achieve the desired configurations and stiffnesses. Some embodiments may be formed of a barium sulfate loaded polyurethane. [0093] Although the above embodiments have been described in language that is specific to certain structures, elements, compositions, and methodological steps, it is to be understood that the technology defined in the appended claims is not necessarily limited to the specific structures, elements, compositions and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed technology. Since many embodiments of the

technology can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.