Obturator, sheath, and method of use thereof

Abstract

The obturator includes a hollow distal end portion having a distal end and a side hole located proximal to the distal end for receiving a guidewire and directing the guidewire laterally from the obturator.

Description

[Technical field]

[0001] The present disclosure relates to obturators, cannula assemblies, and methods for positioning or repositioning guidewires and cannulas. [Background technology]

[0002] Modern medical techniques generally require balancing patient comfort with the time it takes to perform procedures, the cost of those procedures, and the risks associated with them. If an error occurs during a procedure, it is desirable to correct the error with as little deviation from the correct procedure as possible and without increasing the risks, such as having to perform multiple penetrations of the subject's skin.

[0003] Antegrade peripheral revascularization may require, for example, guidewire access to the superficial femoral artery via needle puncture into the common femoral artery (CFA). The CFA is often the site of choice because the femoral head is inferior, facilitating effective postprocedure compression for hemostasis, as well as prevention of external bleeding, retroperitoneal bleeding, and pseudoaneurysm formation.

[0004] The initial needle insertion is usually performed blindly, by palpation alone, with fluoroscopy, or with ultrasound visualization, followed by insertion of a guidewire, also typically blind, after which an access sheath is inserted over the guidewire via the Seldinger technique.

[0005] The deep formal artery, or PFA, may be accidentally cannulated instead of the superficial femoral artery (SFA) due to procedural or anatomical factors.

[0006] Procedurally, guidewire insertion is done blindly, requiring a two-handed approach, and many operators do not use ultrasound or fluoroscopy during this step. This means that the guidewire will take whatever initial trajectory it has as it exits the needle. Furthermore, interaction with pre-existing stenotic disease may deflect the guidewire.

[0007] Anatomically, the real-estate of the CFA puncture may be very short (approximately 1-1.5 cm) and the ostium of the PFA (deep femoral artery) tends to be located on the inferior surface of the artery, so that the needle-directed guidewire preferentially enters it (see Figure 1). This can be problematic because SFA access must be achieved before revascularization can take place. Salvaging the guidewire and correcting its trajectory into the SFA increases the time required for the procedure and increases radiation exposure and the amount of contrast used. Furthermore, repeated rethreading of the wire may also injure or tear the PFA.

[0008] It is not uncommon for access to be lost, necessitating a second cannulation, which carries additional risks of bleeding, hematoma, and pseudoaneurysm formation.

[0009] Techniques to prevent cannulation of the PFA have focused on puncturing more proximally on the CFA with the intention of having the wire “bounce” from the posterior wall into the SFA. Such techniques can often be ineffective. Furthermore, the vasculature contains many branches, making such advanced puncture techniques dangerous. For example, puncturing above the inguinal ligament can cause occult retroperitoneal bleeding, which is potentially life-threatening. Calcified plaque on the anterior wall can also deflect the expected path of the guidewire into the PFA. It is not uncommon for the guidewire to snake along the posterior wall rather than bouncing off it.

[0010] Salvaging the cannulation of the PFA involves provisionally withdrawing the sheath and guidewire from the PFA into the CFA and attempting to re-advance the guidewire along the SFA under angiographic guidance. The sheath then tracks over the guidewire once access is secured. During this time, access is most compromised as the sheath may back out of the puncture site on the vessel. Salvage may also be impossible if the puncture is directly adjacent to the ostium of the PFA or if anterior plaque prevents cannulation of the SFA. Summary of the Invention [Problem to be solved by the invention]

[0011] It would therefore be desirable to provide an apparatus or method that would facilitate the introduction of a cannula or guidewire into the correct body lumen, that would avoid or ameliorate at least one of the aforementioned disadvantages, or that would at least provide a useful alternative. [Means for solving the problem]

[0012] In accordance with the present disclosure, an obturator is provided that includes a hollow distal end portion including a distal end and a side hole located proximal to the distal end for receiving a guidewire and directing the guidewire laterally away from the obturator.

[0013] There is also provided in accordance with the present disclosure an obturator including a hollow distal end portion, the distal end portion comprising: A single lumen; A distal end. an end hole at a distal end for receiving a guidewire extending through the single lumen; and a side hole located proximal to the distal end, the side hole for receiving a guidewire extending through the single lumen and directing the guidewire laterally from the obturator, the side hole further being positioned such that when the obturator is located in a first body cavity during use, a second body cavity can be located by flowing contrast agent through the obturator and out the side hole.

[0014] Disclosed herein is a sheath comprising: a substantially hollow body having a proximal end, a distal end, and a single lumen within the distal end, the single lumen being capable of receiving an obturator; an end hole at a distal end for receiving a guidewire extending through the single lumen; and a side hole disposed proximal to the distal end whereby when the sheath is positioned within a first body cavity during use, a second body cavity may be located by flowing contrast agent through the sheath and out the side hole, the side hole further being for receiving a guidewire and directing the guidewire laterally out of the sheath.

[0015] The end holes and the side holes may be accessible from a single lumen.

[0016] The distal end portion may include an end hole located at the distal end for receiving a guidewire. The end hole may be positioned such that a guidewire extending therethrough extends substantially parallel to a longitudinal axis of the obturator. The end hole may be offset from the longitudinal axis of the obturator.

[0017] The side hole may be located on one side of the obturator such that a guidewire extending through the side hole extends at an angle to the obturator.

[0018] The distal end portion may taper towards the distal end. The side hole may be located proximal to the taper. The taper may extend from the side hole to the distal end. The taper may alternatively extend from a location proximal to the side hole to the distal end.

[0019] The side hole may have one of a square, rectangular, triangular shape, a circle, or an oval shape. The side hole may alternatively have a teardrop shape. The teardrop shape may include a distally directed apex.

[0020] The obturator may further include a slit extending between the end hole and the side hole.

[0021] The obturator may further include one or more orientation markings positioned on a proximal portion of the obturator to indicate the location of the side holes about the periphery of the obturator.

[0022] According to the present disclosure, there is further provided a sheath comprising: a substantially hollow body having a proximal end and a distal end; a side hole disposed proximal to the distal end; Thereby, when the sheath is positioned within a first body cavity during use, a second body cavity may be located by flowing contrast agent through the sheath and out the side hole.

[0023] There is further provided in accordance with the present disclosure a sheath assembly comprising: A sheath, and an obturator as previously described.

[0024] There is further provided in accordance with the present disclosure a sheath assembly comprising: A sheath as mentioned above, and an obturator.

[0025] There is further provided in accordance with the present disclosure a sheath assembly as previously described, wherein the obturator is also as previously described.

[0026] The sheath may be a cannula, with the obturator within the sheath or cannula.

[0027] In accordance with the present disclosure, there is further provided a method of inserting a sheath, the method including passing a sheath assembly as described above over a guidewire and into a body cavity of a subject, the guidewire extending into a side hole of the obturator.

[0028] The sheath may be a cannula.

[0029] There is further provided, in accordance with the present disclosure, a method of repositioning a guidewire, the method comprising: The method includes passing a sheath assembly, including a sheath and an obturator as described above, over a guidewire located in a first (e.g., undesired) body lumen, with the guidewire extending through a side hole in the obturator, the side hole being positioned to redirect the guidewire into a second (e.g., desired) body lumen.

[0030] "General alignment" may be achieved within the body or by withdrawing the assembly with the wires through its side holes from the proximal end of the wires (i.e., the end of the wires that is located outside the body) and reinserting the wires through the sheath assembly or the end holes of the sheath assembly, thereby generally aligning the sheath assembly with the desired body cavity.

[0031] There is further provided, in accordance with the present disclosure, a method of repositioning a guidewire, the method comprising: passing a sheath assembly, including a sheath and an obturator as previously described, over the guidewire, the guidewire extending through an end hole of the obturator and into the subject; determining extension of the guidewire and sheath into a first body cavity of the subject; retracting the guidewire into the sheath assembly; and advancing a guidewire through the side hole of the sheath assembly and into the second body cavity of the subject.

[0032] There is further provided, in accordance with the present disclosure, a method of repositioning a sheath, the method comprising: performing the method described above to reposition the guidewire; retracting the sheath assembly over the guidewire until the obturator is in general alignment with the second body lumen; and advancing the sheath assembly into the second body cavity.

[0033] The obturator may include an end hole, a side hole, and a slit extending between the end hole and the side hole, and the step of retracting the sheath assembly along the guidewire until the obturator is generally aligned with the second body lumen may then include retracting at least the obturator until the guidewire is captured within the obturator through the slit.

[0034] Again, the sheath may be a cannula.

[0035] Some embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0036] [Figure 1a] FIG. 1 shows PFA cannulation. [Figure 1b] FIG. 1 shows cannulation of the SFA. [Diagram 2] FIG. 1 illustrates an obturator, also known as a dilator or introducer, according to the present teachings, with a guidewire (shown in dashed lines) extending from a front hole (first hole) and a side hole (second hole) at the distal end portion of the obturator. [Diagram 3] FIG. 13 shows a cannula assembly with a guidewire running therethrough and a valve attached to an extension tube into a side port of the cannula hub. [Figure 4] FIG. 13 illustrates the distal region of the cannula assembly, where the distal end portion of the obturator includes a slit. [Figure 5a] FIG. 13 shows a shape with side holes. [Figure 5b] 11A-11C are diagrams showing different shapes of side holes. [Figure 6a] 13A-13C show certain configurations of the distal end portion of the obturator. [Figure 6b] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 6c] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 6d] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 6e] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 6f] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 6g] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 6h] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 6i] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 6j] 13A-13C show alternative configurations for the distal end portion of the obturator. [Figure 7] 1 is a flow chart illustrating a method of cannulation. [Figure 8a] FIG. 8 illustrates steps of the method of FIG. [Figure 8b] FIG. 8 illustrates steps of the method of FIG. [Figure 8c] FIG. 8 illustrates steps of the method of FIG. [Figure 8d] FIG. 8 illustrates steps of the method of FIG. [Figure 8e] FIG. 8 illustrates steps of the method of FIG. [Figure 8f] FIG. 8 illustrates steps of the method of FIG. [Figure 8g] FIG. 8 illustrates steps of the method of FIG. [Figure 8h] FIG. 8 illustrates steps of the method of FIG. [Figure 8i] FIG. 8 illustrates steps of the method of FIG. [Figure 8j] FIG. 8 illustrates steps of the method of FIG. [Figure 8k] FIG. 8 illustrates steps of the method of FIG. [Figure 9a] 1A shows a longitudinal cross section through a distal end portion of an obturator in accordance with the teachings of the present invention. [Figure 9b] 13A-13C show transverse cross sections through an alternative obturator in accordance with the teachings of the present invention. [Figure 9c] FIG. 1 shows a longitudinal cross section of a vascular sheath or cannula. [Figure 10] FIG. 13 shows a longitudinal cross section through a distal end portion of the obturator including quartering mechanisms. [Figure 11] FIG. 13 shows a longitudinal section through a distal end portion of an obturator including an alternative quadrant feature. [Figure 12] FIG. 13 shows a longitudinal section through a distal end portion of an obturator including an alternative quadrant feature. [Figure 13] FIG. 13 shows a longitudinal cross section through the distal end portion of the obturator. [Figure 14a] FIG. 13 illustrates a cross-sectional end view of a distal end portion of an alternative obturator. [Figure 14b] FIG. 13 shows a longitudinal cross-sectional view of a distal end portion of an alternative obturator. [Figure 15a] FIG. 13 shows a longitudinal cross section through a distal end portion of an obturator that includes multiple lumens. [Figure 15b] FIG. 13 shows a longitudinal cross section through a distal end portion of an obturator that includes multiple lumens. [Figure 16] FIG. 13 shows a longitudinal cross section through a distal end portion of an obturator that includes multiple lumens. [Figure 17] FIG. 2 illustrates a sheath assembly according to the present teachings introduced into an undesired body lumen, with a guidewire extending through a side hole into a desired body lumen. [Figure 18] 1 illustrates a sheath or cannula in accordance with the present teachings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The present disclosure relates to an obturator, a sheath assembly including such an obturator, and a method of using the sheath assembly. The sheath assembly is described below as a cannula assembly for exemplary purposes only. It will be appreciated that the obturator of the present invention may be used in other assemblies without departing from the teachings herein.

[0038] The obturator includes at least one side hole and generally two holes, a side hole and an end hole, through which a guidewire may extend. The first of the holes, the end hole, is generally axially positioned relative to the cannula assembly. With a correctly positioned guidewire, this first hole is the only hole that is used, as the cannula, which tracks or advances along the guidewire, will follow the guidewire into the correct (i.e., desired) body cavity. With an incorrectly placed guidewire, the second of the holes, the side hole, is used. Advancement of the guidewire through the second hole will cause the guidewire to extend into the desired body cavity. The cannula assembly may then be advanced along the guidewire into the desired body cavity.

[0039] The obturator is intended to improve the ease and speed of salvaging an incorrectly placed guidewire with minimal change or disruption to existing clinical procedure workflow. The obturator may also help to secure arterial access and minimize inadvertent loss of access during salvage. An advantage of using the obturator of the present invention in salvaging an incorrectly placed guidewire and sheath assembly is reduced patient and staff exposure to unnecessary radiation and iodine contrast.

[0040] Generally, the present disclosure is made in the context of the vasculature of a subject (i.e., a patient) and the vascular lumen of that vasculature. However, it will be appreciated that the teachings of the present invention may be similarly applied to other lumens of the body, such as other branching vessels of the body beyond the CFA, including both arteries and veins. For example, it may be used for selective cannulation of the heart, visceral arteries, upper limbs, carotid arteries, brain, etc.

[0041] 1 illustrates the guidewire 108 being incorrectly placed through the needle 110 (FIG. 1a), followed by correct placement of the guidewire 108 (FIG. 1b) due to the guidewire 108 being repelled off the wall 112 of the vascular lumen 108 near the ostium 114. In the structure illustrated in FIG. 1, the various portions of the vasculature 100 are the CFA 102, the SFA 104, and the PFA 106.

[0042] The obturator disclosed herein may allow an interventionist or physician to avoid guidewire recoil from the walls of the vascular lumen and the uncertainty of correct placement with other known techniques. An embodiment 200 of an obturator in accordance with the teachings of the present invention is shown in FIG. 2. The obturator 200 generally includes a hollow distal end portion 202 that includes a first bore 204 and a second bore 206, both for receiving a guidewire.

[0043] The term "receive" as used in connection with a guidewire can mean that the bore passes over a guidewire already in place within the subject, or that the guidewire is advanced through the bore, or another meaning as determined by the context in which the term is used.

[0044] Obturator 200 further includes a hub 208 and a grip 210. Hub 208 is for connection to a cannula or other medical device in a known manner. Similarly, grip 210 can take any known shape and is for grasping during removal of obturator 200.

[0045] Distal end portion 202 extends proximally of obturator 200 from distal end 212. Distal end portion 202 tapers toward distal end 212. Taper 214 extends proximally of obturator 200 from distal end 212. Taper 214 facilitates introduction of the obturator into a subject (not shown).

[0046] Distal end 212 is sized to have the same or slightly larger diameter as the guidewire during use. The subject's skin may recoil into circumferential contact with the guidewire after removal of the needle used to place the guidewire. The close match of distal end 212 of obturator 200 to the diameter of the guidewire facilitates insertion of obturator 200 into a pre-existing puncture in the patient's skin.

[0047] Second hole 206, which may be interchangeably referred to as a side hole or transverse hole, may be located within taper 214 or proximal to the taper as shown in FIG. 2. Locating second hole 206 proximal to taper 214 means that the leading edge of second hole 206 may direct the guidewire along a transverse trajectory at a greater angle relative to longitudinal axis 216 of obturator 200. Additionally, the leading and trailing edges of second hole 206 are the same diameter, resulting in a reduced likelihood that second hole 206 will catch on the subject's skin during insertion of obturator 200.

[0048] The first hole 204 is located at the distal end 212. The second hole 206 is located proximal to the first hole 204. As used herein, the term "proximal" and similar terms refer to being located near the end of an obturator, cannula, or other medical device where a physician or interventionalist applies manual control of the medical device. Conversely, "distally" and similar terms refer to being located away from that end. Thus, the distal end of a medical device is the end of that device away from the end where direct manipulation is applied by the physician or interventionalist.

[0049] The first bore 204 is positioned such that a guidewire extending therethrough extends substantially parallel to the longitudinal axis 216 of the obturator 200. In some embodiments, the first bore 204 is coaxial or axially aligned with the longitudinal axis 216. The first bore is offset from the longitudinal axis 216 of the obturator 200. Because the obturator 200 can be flexible, the parallelism and axial alignment can be determined tangentially to the distal end 212.

[0050] In this embodiment, the second hole 206 is located on one side of the obturator 200. Thus, a guidewire extending through the second hole 206 extends at an angle relative to the obturator 200. For illustrative purposes, Figure 2 shows the guidewires 218, 220 extending from the first hole 204 and second hole 206, respectively, in dashed lines as they do not form part of the obturator 200.

[0051] The second holes 206 may have any desired shape. For example, the second holes 206 may have a square, rectangular, or triangular shape. In the embodiment shown in Figure 2, the second holes 206 have a rectangular shape (although strict rectangularity is not required to have a "rectangular" shape).

[0052] Second hole 206 is located around the periphery of obturator 200. Second hole 206 thus extends from a hollow lumen of the obturator, such as a lumen known in the art, through the wall of obturator 200 such that a guidewire can enter the body cavity through the second hole.

[0053] The obturator 200 of FIG. 2 further includes one or more, here one, orientation markings 222. The markings 222 are located on the proximal portion of the obturator to assist the physician or interventionist in locating the distal end region within the subject, for example in relation to the profunda or SFA. In some embodiments, the markings are located toward the distal end of the obturator and can be located fluoroscopically, ultrasound, or by estimation to provide similar assistance. The markings 222 indicate the location of the second hole around the circumference of the obturator. This allows the physician or interventionist to know where the second hole 206 is located relative to the desired body cavity. If more than one side hole is provided, there may be a marking for each side hole, as discussed below.

[0054] 9a illustrates a schematic longitudinal cross-section of an alternative distal end portion 900 of an obturator 908 in accordance with the teachings of the present invention. In one exemplary embodiment, the side hole 910 may have an oval shaped configuration. The oval shape may have a major axis length of 2 mm to 15 mm, for example, in the longitudinal direction of the hole 910 along the distal end portion 900. The oval shape may have a minor axis length of 0.33 mm to 3.66 mm, for example, in the transverse or lateral direction of the hole 910 along the distal end portion 900. In other embodiments, the side hole may be circular, or symmetrical or asymmetrical elliptical, triangular, square, rectangular, or may have a teardrop shape.

[0055] The obturator may include a single side hole as described with reference to FIG. 2. In this embodiment, the obturator may instead include two, three, four, or any other number of side holes, as desired. Here, the obturator 908 includes four side holes. The side holes are positioned at various distances from the distal tip 913 so as not to materially weaken the distal end portion 900. The holes are positioned at the 12 o'clock (912), 3 o'clock (914), 6 o'clock (910), and 9 o'clock (916) positions, respectively, as best shown in FIG. 9b. Thus, the holes 910-916 are equidistantly spaced around the circumference of the distal end portion 900.

[0056] 9b is a view along the longitudinal axis of a transverse cross section of the distal end portion 900 of the obturator 908. The side hole or holes may be radiopaque under fluoroscopy or may be lined or coated with strips or shapes of material of different densities or characteristics that reinforce various portions of each hole and allow them to be properly independently manipulated during repositioning of the guidewire and obturator, respectively.

[0057] The obturator may include a single lumen, dual or triple lumen with a quadrant mechanism as desired to facilitate selective control of the guidewire through each of the holes 140-146. Guidewire control and multiple lumens are discussed with reference to Figures 10-17.

[0058] 9c diagrammatically depicts a longitudinal cross section of the proximal and distal ends of a vascular sheath or cannula 902. Proximally, the cannula 902 includes a hemostasis valve, not shown but well understood in the art, within the hub 904. The hub 904 sits outside the skin during use and is the part of the cannula assembly from which all cannulation begins (discussed in further detail with reference to FIG. 3).

[0059] Cannula 902 includes a lumen 906 and a flushing port (see port 320 in FIG. 3 ) that allows fluid or contrast to be aspirated or injected along lumen 906. Obturator 908 is positioned within lumen 906 during use, and fluid or contrast is often injected through cannula 902 and obturator 908 into a subject. The fluid or contrast exits by longitudinal or first hole 922, through hole 918 in obturator 908, through side hole 910 in obturator 908, or both.

[0060] To facilitate delivery of contrast or fluid, the obturator or obturator insert 908 is hollow at its proximal end. The obturator may have a blind end at its distal end or may incorporate a bypass or quarter mechanism (described with reference to Figures 10-12) to divert the guidewire from the desired side hole upon activation of the bypass or quarter mechanism. The bypass or quarter mechanism facilitates repeatable diversion of the path of the guidewire into the desired side hole. In the case of a blind-ended obturator, initial access is typically achieved with a known obturator with a single end hole. Once cannulation of the deep femoral artery is found, the obturator and wire are removed and a blind-ended obturator with a side hole is inserted into the cannula. The entire cannula-obturator assembly is retracted until the side hole is aligned with the femoral artery bifurcation. The wire is advanced along the side hole into the SFA and passed a significant distance. The entire assembly is then withdrawn from the patient over the wire and reintroduced along the guidewire using the obturator or a known obturator having an end hole, thereby achieving in-line cannulation of the SFA.

[0061] The distance between element 918 and element 910 is 0.5-10 cm. The distance between distal end 924 and sheath 902 is 3-20 cm, preferably 11 cm.

[0062] In one embodiment, the sheath 902 may taper towards a distal tip or end 924 leading to an exit or longitudinal bore 922 such that the bore 922 is significantly narrower than the lumen 906 of the sheath 902. The gauge of the sheath 902 may be any suitable for typical peripheral vascular interventions, such as, but not limited to, 4 Fr to 10 Fr.

[0063] Figure 3 shows a cannula assembly 300 that includes a cannula 302 and an obturator 304 as described with reference to Figure 2. Figure 3 shows how a hub 306 of the obturator 304 engages with a hub 308 of the cannula 302.

[0064] Distal end portion 310 of obturator 304 projects distally from cannula 302. Distal end portion 310 thereby enters the subject first and widens the penetration made in the subject, facilitating easier entry of cannula 302 into the subject.

[0065] In this embodiment, the distal end portion 310 protrudes sufficiently so that the second hole 312 is located distal to the cannula 308 .

[0066] Cannula assembly 300 also includes an injection assembly 314. Injection assembly 314 includes a valve 316 and an extension tube 318 that extends into a side port or injection port 320 of cannula hub 302.

[0067] The entire complex, ie, the obturator, the cannula, and the rest of the cannula assembly, may be made from a hypoallergenic, inert, flexible, and stretchable material, such as silicone or a polymer, such as polyurethane.

[0068] The obturators 200, 304 of Figures 2 and 3 each include separate and distinct first and second holes. In contrast, the obturator 400 of Figure 4, which is received within a cannula 402, includes a slit 404 extending between a first hole 406 and a second hole 408. The relevance of the slit 404 will be described with reference to Figure 8.

[0069] 4 tapers towards obturator 400, such that the diameter of cannula 402 at its distal end, when assembled with obturator 400, is the same as the outer diameter of obturator 400. In other cases, cannula 402 may fit snugly enough around obturator 400 to substantially avoid catching on the subject's tissue during insertion and use.

[0070] Both obturators 200, 304 of Figures 2 and 3 include substantially rectangular side holes or secondary holes 206, 312, as shown in Figure 5a. In other embodiments, the side holes or secondary holes 500 may have a teardrop shape, as shown in Figure 5b. The teardrop shape of the side holes or secondary holes 500 includes a distally directed apex 502. Thus, the apex 502 points toward the distal end 504 of the obturator 506. In other alternatives, the apex may be proximally directed or in some other desired orientation.

[0071] The teardrop shape centers a guidewire (not shown) on itself within second hole 500 as it extends through second hole 500. When a slit is used in conjunction with the teardrop shape, the teardrop shape also makes it easier to reintroduce the guidewire into the obturator after repositioning the guidewire from an undesired lumen to a desired lumen of the subject. A teardrop shape may allow the guidewire to bend more gradually as it exits the side hole, but may be more difficult to manufacture than rectangular or other shaped side holes.

[0072] 6 illustrates various embodiments of distal end portions of an obturator in accordance with the teachings of the present invention, each of which is shown extending from a cannula. Each distal end portion tapers toward its respective distal end, e.g., toward the diameter of a guidewire to be received through the obturator. In some embodiments, however, the distal end portion may be blunt, e.g., sized to have an inner diameter the same as or similar to the outer diameter of the guidewire extending therethrough.

[0073] The distal end portions shown in Figures 6a-6c, 6g and 6h each include a second tapered region 600. A second hole 602 may be located in the taper described with reference to Figure 2, in the second tapered region 600, or between the tapered regions as shown.

[0074] Figures 6a-6e, 6i and 6j each show a rectangular second hole, such as that shown in the exploded view of Figure 5a, and similarly, Figures 6f-6h show a teardrop shaped second hole, such as that shown in the exploded view of Figure 5b.

[0075] Figures 6a and 6d-6f show a second hole located closer to the distal end of the distal end portion than Figures 6b, 6c and 6g-6j.

[0076] 6b, 6d, 6g, and 6i each show an embodiment in which the first and second holes are connected by a slit 604 (i.e., leading to an end hole) for returning the guidewire into the lumen of the obturator. As described with reference to FIG. 8, the slit bends around the guidewire while repositioning the obturator on an already repositioned guidewire. The closer the second hole is to the distal end of the obturator, the greater the force that can be applied to the inner wall of the vasculature while repositioning the obturator. Therefore, it may be desirable to position the second hole further proximally within the distal end portion. This makes it easier to fix the obturator in an undesired lumen in vivo while also repositioning the guidewire.

[0077] 7 shows a flowchart 700 of the workflow performed during cannulation. To begin cannulation, a puncture is made in the subject's or patient's skin and into the vasculature: step 702. Typically, the puncture is a micropuncture made by a needle (not shown). A guidewire is then advanced through the needle and into the vasculature: step 704. After step 704, the needle is either generally removed from the guidewire and the sheath threaded thereover (i.e., the cannula assembly), or introduced over the guidewire into the vasculature: step 706.

[0078] The physician then checks whether the cannula assembly is in the correct or desired vessel lumen: step 708. Referring to FIG. 1, this places the cannula assembly in the SFA. This check may be performed using contrast injected into the cannula assembly, for example through extension tube 318 of FIG. 3. The contrast may be detected using known methods. The check may also be performed manually by palpation.

[0079] If the cannula assembly is in the desired lumen, the procedure (e.g., angioplasty) continues: step 710. This involves removing the guidewire and obturator from the cannula and inserting another device, such as a catheter, through the cannula and into the desired vascular lumen.

[0080] If it is determined that the cannula assembly has been advanced into an undesired lumen, the guidewire is retracted into the cannula assembly: step 712. The guidewire is retracted until the tip of the guidewire is aligned with or proximal to the second lumen of the obturator.

[0081] The guidewire is then advanced through a second lumen of the cannula assembly and into the second or desired body cavity of the subject: step 714. Thus, the guidewire is repositioned within the desired body cavity.

[0082] Relatedly, the cannula assembly used up to and including decision step 708 may be a standard cannula assembly known in the art, i.e., a cannula assembly that includes only a single hole in the obturator, which hole is coaxial with the longitudinal axis of the obturator. If it is determined that the guidewire is in an undesired lumen, the cannula assembly may be detached from the guidewire, withdrawn, and a cannula assembly as taught herein is then threaded over the guidewire. Alternatively, a cannula as taught herein may be used from the start.

[0083] The cannula may then be repositioned, for example, into the desired lumen, per step 718. This is accomplished by retracting the cannula assembly (i.e., sheath) over or along the guidewire. Retraction is performed until the obturator is generally aligned with the desired body cavity. The term "aligned" in this context means that as the cannula assembly is advanced back along the guidewire, the obturator, and thus the cannula, is guided into the second or desired body cavity. The procedure may then continue as normal: step 710.

[0084] Thus, Figure 7 illustrates a normal or typical workflow and the workflow involved in repositioning the cannula assembly with minimal interruption to the typical workflow. Referring to Figure 1, the puncture site may be secured by method 700, with the obturator and guidewire being manipulated to redirect the guidewire and hold the sheath inside the PFA, i.e., no additional puncture needs to be made for repositioning. The sheath is only removed from the PFA once the guidewire is safely secured within the SFA. Once the guidewire within the SFA is secured by the sheath, the physician or interventionist may proceed with the lower extremity angioplasty or any other procedure.

[0085] The steps of workflow 700 involving a cannula assembly described herein that includes two holes in the obturator (although the obturator can also include three or more holes) relate primarily to steps 712 through 718. It will be appreciated that a procedure may instead include two obturators, i.e., an obturator whose distal end portion includes only a side hole located proximal to the distal end for directing the guidewire laterally away from the obturator, and a separate obturator that includes an end hole.

[0086] FIG. 8, including FIGS. 8a-8k, illustrates various steps of the workflow of FIG. 7 or the state of the sheath assembly during the execution of those workflows. FIG. 8a illustrates the sheath assembly located in the undesired lumen 800 as determined in step 708. FIG. 8b illustrates the guidewire 802 after retraction and reinsertion or re-advancement along the sheath assembly, extending through the side hole 804. FIG. 8c illustrates how the guidewire 802 rests above the desired lumen 806 after being advanced through the side hole. FIG. 8d illustrates the obturator 808 retracted such that the distal end 810 is proximal of the ostium 812 between the desired lumen 806 and the undesired lumen 800. This retraction step occurs between the introduction of the guidewire 802 into the desired lumen 806: step 716 and the retraction of the sheath 814: step 718. In this state, the obturator 808 and the guidewire 802 are lined up within the sheath 814, as shown in FIG. 8e. Obturator 808 and sheath 814 are then moved back along guidewire 802 into the desired lumen 806: FIG. 8f.

[0087] In an alternative embodiment, obturator 816 includes a slit 818 between end hole 820 and side hole 822, as shown in FIG. 8g. After repositioning guidewire 824 through side hole 822, guidewire 824 is located just distal to side hole 822 in a position generally shown by FIG. 8h. As obturator 816 is retracted, guidewire 824 bends the edges of slit 818 inward until guidewire 824 is pushed back into lumen 826 of obturator 816, as shown progressively in FIGS. 8h-8j. The final position of obturator 816 during retraction is shown in FIG. 8k, with guidewire 824 within lumen 826. Thus, as obturator 816 is advanced, it follows the trajectory of guidewire 824 and enters the desired lumen 828.

[0088] 8c, 8d, and 8e, once the guidewire 824 exits the side hole 822 and enters the second or desired body cavity 806, the sheath assembly is retracted along the guidewire 824 until the guidewire 824 and the extending distal taper of the obturator 816, i.e., the taper between the side hole 822 and the distal end, are forced inside the sheath. In some cases, if the distal taper is long enough, the guidewire 824 is not recaptured within the obturator 816 at this stage. Instead, the two are forced into the sheath due to the reduced cross-section at its distal taper. This force facilitates removal of the obturator 816 from the sheath assembly while the guidewire 824 remains within the second or desired body cavity 806.

[0089] 10-12 show various quadrant systems, each including one or more elements for selectively enabling, assisting, and / or facilitating control of the quadrant mechanism, and possibly the guidewire, between the end hole (or first hole) and the side hole (or second hole). The quadrant system is in each case part of the obturator 1000, 1100. FIG. 10 itself shows more than one quadrant system. In practice, it will be appreciated that only one such quadrant system will typically be provided.

[0090] In one embodiment, the quarter feature is a curved protrusion 1002. The curved protrusion is diametrically opposite the side hole 1004 (e.g., if the side hole 1004 is at 6 o'clock, the protrusion 1002 is at 12 o'clock). The protrusion 1002 is relatively proximal to the side hole 1004. The protrusion 1002 preferably overlaps the side hole 1004 slightly to deflect a guidewire (not shown) into the side hole 1004.

[0091] The shape of the protrusion 1002 may be a symmetrical or asymmetrical hump, or a ledge, or a wedge. The surface of the protrusion 1002 may be smooth, rough, or grooved. The protrusion is expandable, for example with air or liquid, through a conduit (not shown), and may have a collapsed state that allows preferential access of a guidewire through one of the side and end holes, end hole 918, described herein with reference to FIG. 9a, and an expanded or expanded state that directs a guidewire through the other of the side and end holes, side hole 910, described herein with reference to FIG. 9a. The expansion and folding of the protrusion 1002 may be performed similarly to the expansion and folding of a balloon catheter in a known manner.

[0092] In an alternative embodiment, a flap / leaf 1006 may be used. The flap 1006 is located distal to the side hole 1004. The flap 1006 may be oriented to block the main lumen 1008, for example by flipping up (on a hinge, living hinge, or otherwise) to allow a guidewire to pass through the side hole 1004, or to allow a guidewire to pass to the distal end of the main lumen 1008. The flap 1006 may be in a substantially flat form and may be a ball valve mechanism that is rotated between a position where a hole through the ball of the valve is aligned with the main lumen 1008, allowing a guidewire to pass through the ball valve, and a position where the hole is out of alignment with (e.g. perpendicular to) the lumen 1008, preventing access to the distal end. Rotation of the mechanism 1006 may be accomplished by control wires and the like, used herein to control the implantation and removal of medical devices from the vasculature in a manner known per se. The flap 1006 can alternatively change elasticity or stiffness to provide greater resistance to passage through an actuation mechanism (not shown). The change in elasticity or stiffness can be effected electrically (e.g., with an elastomer that changes properties upon electrical stimulation, such as a carbon black filled ethylene-propylene elastomer (cPBE) embedded in an electrically insulating sheet of polydimethylsiloxane) or mechanically (e.g., by winding a very thin spiral wire inside the flap or expanding the flap body), as will be understood by those of skill in the art in view of the present teachings.

[0093] In yet another alternative embodiment, an expanding circumferential ring or donut 1010 is provided. The expanding ring 1010 may expand upon activation to occlude the distal lumen, thereby forcing the guidewire through the side hole 1004. Upon activation, for example when inflated similar to a balloon catheter, the ring 1010 significantly narrows and occludes the lumen 1008, preferentially preventing the guidewire from advancing through the lumen 1008, for example pushing the guidewire out of the side hole 1004. Similarly, feature 1014 is the ring 1010 inside the wall 1016 of the sheath. Upon activation, the ring 1014 is tightened, for example by pulling on a wire which shortens the circumference of the ring 1014, occluding the main lumen 1008 and directing the guidewire out of the side hole 1004.

[0094] 11 and 12 show the steerable device 1102 just distal to the side hole 1104. A small channel 1106 is embedded inside the wall 1108 of the sheath (e.g., vascular sheath). The channel connects the steerable device 1102 to the proximal portion of the sheath (see hub 308 in FIG. 3). This channel 1106 allows for the transport of a medium such as fluid or air into the steerable device to manipulate and adjust the size as shown in FIG. 11 where the steerable device is inflated, and in FIG. 12 where the steerable device is deflated. Similar mechanisms can be used for inflation / deflation and control of the other mechanisms described with reference to FIG. 10.

[0095] In an alternative embodiment, the quadrant mechanism for guiding the guidewire to the side hole utilizes an intraluminal expander or bag that is intended to act as a steerable device as discussed with reference to Figures 11 and 12. This steerable device is connected to the outside via a channel embedded inside the wall of the vascular sheath and can be activated via injection of a medium such as saline, a contrast agent, or a gas such as carbon dioxide.

[0096] Upon activation, the steerable device expands to completely occlude the lumen of the vascular sheath. This expansion may also stretch the nearby sheath and secondarily expand the width of the side hole to facilitate cannulation of the tip of the guidewire into the newly enlarged opening. Furthermore, once the main lumen is completely occluded, contrast may be flowed through the side hole to visualize the deep femoral artery or ostia of the undesired lumen.

[0097] It will be appreciated that the locations of the quadrant features and other elements of the quadrant system shown in Figures 1-12 may not be as shown in relation to the side holes 1004, 1104, 1204. However, the placement of those quadrant features to achieve the purpose of directing a guidewire through the side holes 1004, 1104, 1204 will be apparent to one of ordinary skill in the art in view of the present teachings.

[0098] One or more obturators may instead be used as part of a quadrant system. With reference to FIG. 13, the distal end 1300 of the obturator 1302 is designed to fit snugly inside the lumen of a vascular sheath (see, e.g., FIG. 9). The tip of the obturator 1302 may be tapered or bullet shaped to facilitate puncture of the arterial wall during entry into the vasculature, or into the wall of another body cavity if desired. In some embodiments, the obturator may have a slightly larger gauge than the sheath and may inflate and stretch the wall of the sheath upon entering the lumen of the sheath.

[0099] Obturator 1302 includes an inner lumen 1306 with a side hole 1304, and is blind-ended at distal end 1300. In some cases, an obturator with only an end hole, such as a conventional obturator, may be used until it is determined that the obturator has entered the incorrect body cavity. That obturator may then be removed and obturator 1302 may be threaded over the guidewire. The intent of using obturator 1302 is to shift the end of the guidewire into the desired body cavity. The cannula assembly may then be advanced over the properly placed guidewire.

[0100] The side holes 1304 may be oval, elliptical, quadrilateral, or otherwise.

[0101] In an alternative embodiment shown in FIG. 14a, the side hole 1400 may be offset from the main lumen 1406 and aligned with the end hole 1404 of the obturator 1402 as shown in FIG. 14b. The end hole is not exactly at the distal end of the obturator, but faces forward relative to the longitudinal axis of the obturator and is referred to herein as the end hole. Also, alignment of the end hole and the side hole refers to both being generally in the same plane defined by the longitudinal axis of the obturator and a radial line perpendicular to the longitudinal axis. Furthermore, the side hole and the end hole may both be on one side of the longitudinal axis. The main lumen 1406 may exit at or near the edge of the distal end 1408 and be offset from the midline as shown in FIG. 14a and FIG. 14b. The quarter mechanism described with reference to FIG. 10 and FIG. 11 may be used to guide the guidewire between the hole 1404 and the hole 1400.

[0102] In FIG. 14b, the proximal lumen is at 12 o'clock and the distal lumen is in the center.

[0103] FIG. 15a shows an embodiment of an obturator 1500, particularly a distal end portion 1506, that includes two separate lumens 1502, 1504. The lumens 1502, 1504 may be cannulated separately. For example, initially (e.g., in step 706), a sheath is threaded over a guidewire, which extends into end hole 1508. Once it is determined that the guidewire has been incorrectly positioned in an undesired body cavity, the obturator 1500 is retracted, leaving the cannula or sheath in place. The obturator 1500 is removed from the guidewire and rethreaded over the guidewire, which extends through side hole 1510. As the obturator 1500 emerges through the distal end of the sheath, with side hole 1510 pointed toward the desired body cavity, the guidewire bends out of the undesired body cavity and into the desired body cavity. The sheath assembly may then be advanced into the desired body cavity.

[0104] To accomplish this, there is generally some bend or extra space inside the sheath to allow the portion of the obturator between the side hole 1510 and the tip 1512 to advance next to the guidewire through the sheath. Alternatively, a groove 1514 (see FIG. 15b) may be incorporated into that portion of the obturator, and the guidewire is received in that groove while the obturator 1500 is advanced along the sheath.

[0105] One lumen 1504 is shorter than the other lumen 1502 and exits at a side hole 1510 , while the other lumen 1502 is longer and exits centrally at a hole 1512 at the distal end 1512 of the obturator 1500 .

[0106] FIG. 16 illustrates an obturator 1600, which includes a bypass lumen 1602 to achieve cannulation into the body cavity from a side hole 1604, as previously described, with the difference that the distal lumen continues with a steep taper to an end hole 1606. This allows only straight cannulation with thin wires (e.g., 0.018 inches or 0.014 inches). The end hole 1606 has a smaller diameter than the side hole 1604. Thus, standard wires (i.e., 0.035 inches) are bypassed out of the side hole 1604. This allows for preferential cannulation into the SFA while allowing wire access to be maintained in the PFA. It will be appreciated that a similar structure allows for preferential straight cannulation by providing an end hole with a larger diameter than the side hole. Correspondingly, a lumen of a larger diameter than the lumen extending to the side hole needs to extend from the main lumen to the end hole. Additionally, the obturator lumen may simultaneously permit positioning of a thin guidewire into a smaller diameter hole and a larger guidewire through a larger diameter hole, and even if the holes are the same size or otherwise, positioning a guidewire into one hole allows a second guidewire to exit the other hole.

[0107] The present disclosure, and in particular FIG. 18, also discloses a sheath 1800. The sheath 1800 includes a side hole 1802 and a distal end 1804. In use, an obturator (whether as taught herein or known) is used with the sheath 1800 with a guidewire threaded through its end hole, and the obturator can be removed if it is determined that the sheath is in an undesirable lumen. Contrast is then flowed (e.g., injected) through the sheath 1800. The contrast exits the distal end 1804 if the distal end is open. The contrast does not exit the distal end 1804 if the distal end is blind (i.e., closed). In either case, the contrast exits the side hole 1804. The sheath 1800 may then be moved as necessary until the side hole 1804 is aligned with the desired lumen, as indicated by contrast agent flowing from the side hole into the desired lumen, which is visualized in a known manner. The guidewire may then be removed and an obturator as taught herein is inserted, with the guidewire threaded so that its side hole aligns with the sheath's side hole 1804, for example, as determined when the obturator's hub abuts the sheath's hub, or by providing indicia on one or both of the obturator and sheath to indicate the relative alignment of the side holes. The guidewire is then threaded through the obturator's side hole and protrudes out of the sheath's 1800 side hole into the desired lumen. The sheath assembly may then be withdrawn and the sheath and / or sheath assembly may be repositioned over the guidewire, such that the guidewire protrudes distally of the sheath 1800, which may then be advanced into the desired lumen. The sheath 1800 may be a cannula or a cannulation catheter, or other medical device.

[0108] 17 shows how the obturator is positioned in situ after cannulation of the side hole 1704, with the distal end 1700 in the deep femoral artery or PFA 1706 and the guidewire 1702 inside the SFA 1708. For illustrative purposes, the hub 1710, CFA 1712, and cannula 1714 are also shown.

[0109] The obturator, sheath / cannula assemblies described herein allow for easy cannulation of a "side hole" on the obturator by engaging the guidewire and redirecting the guidewire from within the vascular sheath to exit the body of the obturator more proximally at an angle to the obturator, whereby the guidewire is intended to pass distally through the SFA.

[0110] In some embodiments, a combination of a vascular sheath and a hollow shafted but blind ended obturator may be used, with the obturator having a side exit some distance away from the blind end. Of note, the side hole on the obturator is equal to or larger than the size of the side hole on the sheath. The shaft of the blind ended obturator may be made of a stiffer material and may be of slightly larger diameter than the vascular sheath to allow the obturator to inflate and stretch the outer sheath when the obturator is inserted inside the sheath.

[0111] This is depicted in FIG. 17, where the obturator side hole and the sheath side hole are oriented and aligned, for example, by using one or more indicia, such as external markings, or radiopaque markings that are visible on an x-ray. In some other embodiments, tactile feedback, such as a "click" and partial lock / grip, may be used when the obturator is aligned with the cannula. In this preferred embodiment, the side hole on the sheath may be approximately 3-6 cm from the distal tip. The blind-ended tip obturator is slightly longer than the length of the vascular sheath between the proximal hub and the most distal side hole. In a variation of this embodiment, the obturator may have a smaller distal channel or lumen so that the obturator can be introduced through the sheath over an existing thin wire located inside the PFA, whereby the SFA may be preferentially cannulated through the side hole with a larger wire, for example, two wires may be inside the obturator, one thin wire extending distally from the end hole and the other larger wire extending laterally from the side hole. See Figures 14 and 16.

[0112] The recognized workflow for use of the obturator is as follows: for a blind-ended obturator to remove the wire and leave the sheath in the PFA: inserting the obturator, e.g., such that the tip of the obturator extends into the PFA; Using contrast injection to localize the bifurcation between the desired and undesired lumens, e.g., PFA / SFA, while slowly withdrawing the entire assembly until it reaches the correct level as indicated by contrast flowing into the desired lumen (this step may be incorporated into the method of FIG. 7); and Rotate the sheath assembly until the side hole is aligned with the desired lumen, e.g., aligned with the PFA hole, with or without a final confirmatory angiogram being performed to verify alignment prior to cannulation.

[0113] For a thin hollow obturator, the existing wire is changed to a 0.018 inch, or even smaller, wire to maintain access to the undesired lumen, e.g., PFA, and the obturator is advanced or carried over the wire to the end of the desired lumen, e.g., SFA, as before. The remainder of the workflow is the same. Insertion of the second wire causes a detour along the side hole.

[0114] In alternative embodiments, the side holes may incorporate a mechanism for detecting the edges of the puncture, for example by flashback or cessation of blood into the aspiration channel or by injection of contrast along the injectable channel, which may enable the activation of a separate mechanism, not described here, for suturing or otherwise closing the puncture site.

[0115] It is anticipated that contrast will be flowed through both the distal end and the side hole, or preferentially through one or the other, to indicate that the side hole is located proximal to the bifurcation of the CFA into the SFA and PFA, i.e., the bifurcation between the desired and undesired lumens, and in position for placing a wire. It is also anticipated that a radiopaque marker on the side of the sheath will allow the operator to easily align the side hole with the opening of the undesired lumen by rotating the sheath until the marker is in the proper position.

[0116] It is further envisioned that in some embodiments, the sheath may be withdrawn at its side hole over the guidewire now extending into the desired lumen and reintroduced over the wire into its main working lumen or longitudinal central lumen, so that work may continue further distally along the desired lumen.

[0117] It is anticipated that this concept may be utilized for retrograde cannulation, facilitating easy cannulation of the internal iliac arteries, crossing of aortic bifurcations, visceral branches during procedures requiring retrograde access, or cannulation of other body cavities. Sizes may range up to 24F or more, with sheath and obturator lengths increased to 15cm or more as needed for a particular application, but the principles remain the same without departing from the teachings herein.

[0118] In this specification and the claims that follow, unless otherwise stated, the word "comprise" and variations thereof, such as "comprises" and "comprising", imply the inclusion of a stated integer, step, or group of integers or steps, but does not exclude any other integer or step, or group of integers or steps.

[0119] The various embodiments and variants thereof illustrated in the accompanying drawings and / or described herein are merely exemplary and are not intended to limit the scope of the present invention. It is recognized that many variants of the present invention are contemplated, as would be apparent to one of ordinary skill in the art having the benefit of this disclosure. Rather, the scope and breadth provided by this document should be limited only by the claims provided herein, and the plain meaning of each of the claim terms and phrases or the meaning provided clearly and unambiguously in this application shall apply.

[0120] Reference herein to any prior publication, to any information derived from said prior publication, or to any known matter is not, and should not be understood as, an admission, acknowledgement, or suggestion that said prior publication, or any information derived from this prior publication, or to any known matter, forms part of the common general knowledge in the field of endeavor to which this specification pertains. [Explanation of symbols]

[0121] 100 Vasculature 102 CFA 104 SFA 106 PFA 108 Guidewire 110 needles 112 Wall 114 Small hole 200 Obturator 202 hollow distal end portion 204 First Hole 206 Second Hole 208 Hub 210 Grip 212 Distal end 214 Taper 216 Longitudinal axis 218 Guidewire 220 Guidewire 222 marks 300 Cannula Assembly 302 Cannula 304 Obturator 306 Hub 308 Hub 310 Distal end section 312 Second Hole 314 Injection Assembly 316 Valve 318 Extension tube 320 Side Port 400 Obturator 402 Cannula 404 Slit 406 First Hole 408 Second Hole 500 Second Hole 502 Vertex 504 Distal end 506 Obturator 600 Second tapered region 602 Second Hole 604 Slit 800 lumen 802 Guidewire 804 Side hole 806 Desired Lumen 808 Obturator 810 Distal end 812 Small hole 814 Sheath 816 Obturator 818 Slit 820 End hole 822 Side hole 824 Guidewire 826 Lumen 828 Desired Lumen 900 Distal end section 902 Cannula 904 Hub 906 Lumen 908 Obturator 910 Side hole 912 Side hole 913 Distal tip 914 Side hole 916 Side hole 918 holes 922 First Hole 924 Distal end 1000 Obturator 1002 Projection 1004 Side hole 1006 Flap 1008 Main lumen 1010 Ring 1014 Ring 1100 Obturator 1102 Steerable Devices 1104 Side hole 1106 Small Channel 1108 Sheath Wall 1204 Side hole 1300 Distal end 1302 Obturator 1304 Side hole 1306 Lumen 1400 side hole 1402 Obturator 1404 End hole 1406 Main lumen 1408 Distal end 1500 Obturator 1502 Lumen 1504 Lumen 1506 Distal end section 1508 End hole 1510 Side hole 1512 Tip 1514 Groove 1600 Obturator 1602 Diversion lumen 1604 Side hole 1606 End hole 1700 Distal end 1704 Side hole 1706 PFA 1708 SFA 1710 Hub 1712 CFA 1714 Cannula 1800 Sheath 1802 Side hole 1804 Distal end

Claims

1. 1. An obturator comprising a hollow distal end portion, The distal end portion is A single lumen; A distal end. an end hole at the distal end for receiving a guidewire extending through the single lumen; a side hole located proximal to the distal end for receiving a guidewire extending through the single lumen from a location proximal to the side hole and directing the guidewire laterally away from the obturator, wherein when the obturator is located in a first body cavity during use, a second body cavity is located by flowing contrast media through the obturator and out the side hole; comprising the obturator further comprising a slit extending axially between the end hole and the side hole, the side hole having a teardrop shape with a distally directed apex, the apex opening onto the slit for directing a guidewire passing through the side hole toward the slit.

2. The obturator of claim 1 , wherein said end aperture is offset from a longitudinal axis of said obturator.

3. 3. The obturator of claim 1 or 2, wherein said distal end portion is tapered toward said distal end.

4. The obturator of claim 3 , wherein said side hole is located proximally of said taper.

5. 5. The obturator of claim 1, further comprising one or more orientation markings positioned on a proximal portion of the obturator to indicate the location of the side holes about a periphery of the obturator.

6. The obturator of claim 1 , wherein the slit is defined by edges configured to bend inwardly to receive the guidewire within the single lumen.

7. 1. A sheath assembly comprising: An obturator according to any one of claims 1 to 6, A sheath, a substantially hollow body having a proximal end, a distal end, and a single lumen within the distal end for receiving an obturator; an end hole at a distal end of the sheath for receiving a guidewire extending through the single lumen of the sheath; a side hole disposed proximal to a distal end of the sheath; wherein when the sheath is positioned in a first body lumen during use, a second body lumen is located by flowing contrast through the sheath and out a side hole of the sheath, the side hole being further for receiving a guidewire and directing the guidewire laterally out of the sheath; A sheath assembly comprising:

8. The sheath assembly of claim 7 , wherein the sheath end hole and the sheath side hole are accessible from the single lumen.

9. The sheath assembly of claim 8, wherein the sheath is a cannula and the obturator is within the sheath.

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