Access to the pericardial space

Abstract

The medical access system comprises an inner needle assembly, including an inner needle shaft configured to be at least partially slidably positioned within the delivery lumen of an outer needle assembly, the inner needle shaft comprising a narrower distal portion, a wider portion proximal to the narrower distal portion, and a transition segment between the narrower distal portion and the wider portion. The first delivery lumen within the inner needle shaft extends from the proximal end of the inner needle shaft to the distal end opening of the distal end of the narrower distal portion, and the second delivery lumen within the inner needle shaft may extend from the proximal end to the distal opening associated with the transition segment.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Patent Application No. 63 / 505,674, titled "Medical Access System," filed on June 1, 2023, the disclosure of which is hereby expressly incorporated by reference in its entirety for all purposes.

Background Art

[0002] Access to the pericardial space through the pericardium can be difficult. The pericardial space can be a relatively narrow space. The force required to puncture the pericardium, combined with the narrowness of the pericardial space, can often overshoot the pericardial space. Overshooting the pericardial space can cause inadvertent entry into adjacent and / or underlying cardiac chambers such as the cardiac ventricles or atria. In addition to the challenges of accessing the pericardial space, some patients may have little or no fluid in the pericardial space. Using a large standard - sized needle to access the pericardial space can, if the cardiac ventricle is punctured, potentially cause excessive bleeding upon withdrawal of the needle.

Summary of the Invention

Means for Solving the Problems

[0003] This specification describes methods and devices relating to medical access systems configured to provide access to the pericardial space. In some cases, the medical access system may comprise an outer needle assembly and an inner needle assembly having an inner needle shaft having a narrower distal portion and a wider portion proximal to the narrower distal portion. A transition segment may extend between the narrower distal portion and the wider portion. At least a portion of the inner needle shaft may be configured to be slidably positioned within the delivery lumen of the outer needle assembly. In some cases, the inner needle assembly may be targeted to advance relative to the outer needle assembly to position at least a portion of the narrower distal portion of the inner needle shaft within the cardiac pericardial space. In some cases, the inner needle assembly may advance relative to the outer needle assembly to position the distal opening on the transition segment of the inner needle shaft within the cardiac pericardial space. The distal opening on the transition segment may be positioned within the cardiac pericardial space, while a portion of the narrower distal portion may be positioned within the cardiac ventricle adjacent to the cardiac pericardial space. In some cases, a medical access system may comprise an outer needle assembly and an inner needle assembly having an inner needle shaft having a uniform or substantially uniform outer diameter. At least a portion of the inner needle shaft may be configured to be slidably positioned within the delivery lumen of the outer needle assembly. In some cases, the inner needle assembly may advance relative to the outer needle assembly to target the distal end of the inner needle shaft to position it within the cardiac pericardial space. In some cases, the outer needle assembly may advance relative to the inner needle assembly to position the distal end opening of the distal end of the outer needle shaft within the cardiac pericardial space. The distal end opening of the outer needle shaft may be positioned within the cardiac pericardial space, and the distal end of the inner needle shaft may be positioned in the cardiac ventricle adjacent to the cardiac pericardial space.

[0004] The methods and structures disclosed herein for treating patients also encompass similar methods and structures performed on or placed on simulated patients, which are useful, for example, training, demonstration, treatment, and / or device development, and similar purposes. Simulated patients may be physical, virtual, or a combination of physical and virtual. Simulations may include simulations of all or part of a patient, such as the whole body, a part of the body (e.g., the chest), a system (e.g., the cardiovascular system), an organ (e.g., the heart), or any combination thereof. Physical elements may be natural, synthetic, or any combination of natural and synthetic, including human or animal carcasses or parts thereof. Virtual elements may be entirely in silica or overlaid on one or more of the physical components. The virtual elements may be presented on any combination of screens, headsets, holographics, projections, loudspeakers, headphones, pressure transducers, and temperature transducers, or using any combination of preferred technologies.

[0005] For the purpose of summarizing this disclosure, specific aspects, advantages, and novel features are described herein. It should be understood that not all such advantages can necessarily be achieved according to any particular embodiment. Accordingly, the disclosed embodiments may be carried out in a manner that achieves or optimizes one or more advantages, or a group of advantages, as taught herein, without necessarily achieving other advantages that can be taught or suggested herein.

[0006] Various embodiments are shown in the accompanying drawings for illustrative purposes, but should not be construed as limiting the scope of the invention. In addition, various features of different disclosed embodiments may be combined to form additional embodiments which constitute part of this disclosure. Throughout the drawings, reference numerals may be reused to indicate correspondences between reference elements. However, it should be understood that the use of similar reference numerals in relation to multiple drawings does not necessarily imply similarity between the respective embodiments relating thereto. Furthermore, it should be understood that features in each drawing are not necessarily drawn to scale, and their illustrated sizes are presented for illustrative purposes to illustrate aspects of the invention. In general, some of the illustrated features may be relatively smaller than those shown in some embodiments or configurations. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows one or more embodiments of a medical access system deployed within the heart to provide access to the pericardial space of the heart. [Figure 2] Figure 2 provides a side view of the medical access system of Figure 1 according to one or more embodiments. [Figure 3A] Figure 3A provides side cross-sectional views of the deployment of the internal needle assembly shown in Figure 2 into the pericardial space and the deployment of a guidewire into the pericardial space, each using an internal needle assembly, according to one or more embodiments. [Figure 3B] Figure 3B provides side cross-sectional views of the deployment of the internal needle assembly shown in Figure 2 into the pericardial space and the deployment of a guidewire into the pericardial space, each using an internal needle assembly, according to one or more embodiments. [Figure 4A] Figure 4A provides side cross-sectional views of one or more embodiments of the deployment of a first guidewire into the cardiac ventricle using the inner needle assembly of Figure 2, and the deployment of a second guidewire into the pericardial space using the outer needle assembly of Figure 2. [Figure 4B]Figure 4B provides side cross-sectional views of one or more embodiments of the deployment of a first guidewire into the cardiac ventricle using the inner needle assembly of Figure 2, and the deployment of a second guidewire into the pericardial space using the outer needle assembly of Figure 2. [Figure 5] Figure 5 is a process flow diagram illustrating the procedure for accessing the cardiac pericardial space according to one or more embodiments. [Figure 6] Figure 6 provides a side view of a medical access system configured to provide access to the cardiac pericardial space, according to one or more embodiments. [Figure 7A] Figure 7A provides a side cross-sectional view of the deployment of the medical access system of Figure 6 for accessing the cardiac pericardial space, according to one or more embodiments. [Figure 7B] Figure 7B provides a side cross-sectional view of the deployment of the medical access system of Figure 6 for accessing the cardiac pericardial space, according to one or more embodiments. [Figure 8] Figure 8 is a process flow diagram illustrating the procedure for accessing the cardiac pericardial space in one or more embodiments. [Modes for carrying out the invention]

[0008] The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.

[0009] Specific preferred embodiments and examples are disclosed below, but the subject matter of the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses, as well as their modifications and equivalents. Therefore, the claims that may arise from this specification are not limited by any specific embodiment, as will be stated below. For example, in any method or process disclosed herein, the action or operation of the method or process may be performed in any preferred order, and is not necessarily limited to any specific disclosed order. Various operations may be described sequentially as a number of separate operations in a manner that may be useful for understanding a particular embodiment; however, the order in which they are described should not be interpreted as implying that these operations are order-dependent. Furthermore, structures, systems, and / or devices described herein may be embodied as integrated components or as separate components. For the purpose of comparing various embodiments, specific aspects and advantages of these embodiments are described. Not all such aspects or advantages are necessarily achieved by any particular embodiment. Therefore, for example, various examples may be implemented in a manner that achieves or optimizes one or a set of advantages as taught herein, without necessarily achieving other aspects or advantages that may similarly be taught or suggested herein.

[0010] Specific standard anatomical terms for location are used herein to refer to animal, i.e., human, anatomical structures, in the case of preferred examples. Certain spatially relative terms such as “lateral,” “medial,” “superlateral,” “inferior,” “below,” “down,” “up,” “vertical,” “horizontal,” “apex,” and “base,” and similar terms are used herein to describe the spatial relationship of one device / element or anatomical structure to another device / element or anatomical structure, but it is understood that these terms are used herein for ease of explanation to describe the positional relationships between elements / structures as shown in the drawings. It should be understood that spatially relative terms are intended to encompass different orientations of elements / structures in use or operation, in addition to the orientations illustrated in the drawings. For example, an element / structure described as “above” another element / structure may represent a position below or to the other such element / structure with respect to the patient in question or an alternative orientation of the element / structure, and vice versa.

[0011] Accessing the cardiac pericardial space through the pericardium can be difficult. The pericardial space can be a relatively narrow space. The force required to puncture the pericardium, combined with the narrowness of the pericardial space, can often lead to overshooting the pericardial space and inadvertently entering an adjacent cardiac chamber. For example, overshooting the pericardial space can lead to inadvertent entry into an adjacent cardiac ventricle or atrium. Patients with little or no fluid in the pericardial space may make targeting the pericardial space more difficult, such as when performing a dry tap. The use of standard gauge needles to access the pericardial space can result in excessive bleeding. For example, the large hole size of standard gauge needles can create a cut in the myocardium after needle withdrawal if the myocardium is punctured by the standard gauge needle, leading to excessive bleeding through the cut. Excessive bleeding can lead to, for example, cardiac tamponade, shock, and / or other serious complications.

[0012] This specification describes methods and devices relating to medical access systems configured to provide access to the pericardial space. In some cases, the medical access system may comprise an outer needle assembly and an inner needle assembly. The inner needle assembly may comprise an inner needle shaft extending distally from the inner needle hub. The inner needle shaft may comprise a narrower distal portion and a wider portion proximal to the narrower distal portion. A transition segment may extend between the narrower distal portion and the wider portion, for example, by joining the narrower distal portion and the wider portion. In some cases, the narrower distal portion may include a micropuncture needle. At least a portion of the inner needle shaft may be configured to be slidably positioned within the delivery lumen of the outer needle assembly. The inner needle assembly may be configured to advance relative to the outer needle assembly, targeting the positioning of at least a portion of the narrower distal portion within the cardiac pericardial space. If the internal needle assembly overshoots the cardiac pericardial space, for example, if the narrower distal portion is positioned within the cardiac chamber, the internal needle assembly may be advanced further to position the distal opening on the transition segment within the cardiac pericardial space.

[0013] In some cases, a medical access system may comprise an outer needle assembly and an inner needle assembly. The inner needle assembly may comprise an inner needle shaft extending distally from the inner needle hub. In some cases, the inner needle shaft may have uniform or substantially uniform lateral dimensions, such as an outer diameter. In some cases, the inner needle shaft may include a micropuncture needle. At least a portion of the inner needle shaft may be configured to be slidably positioned within a delivery lumen extending through the outer needle assembly. The inner needle assembly may be targeted to advance relative to the outer needle assembly to position the distal end of the inner needle shaft within the pericardial space. If a portion of the inner needle shaft is unintentionally advanced beyond the pericardial space, such as being deployed into the cardiac chamber through the myocardium, the outer needle assembly may advance relative to the inner needle assembly to position the portion of the outer needle shaft within the pericardial space. For example, the distal end opening at the distal end of the outer needle shaft may be positioned within the pericardial space.

[0014] As used herein, “delivery lumen” may refer to any number of lumens, channels, passages, and / or conduits into which a medical device and / or medical device can be advanced, including, for example, a working channel. For example, as used herein, “delivery lumen” may refer to a working channel into which a medical device and / or medical device can be advanced to position it at a target site within a patient.

[0015] Any of the various systems, devices, and apparatus in this disclosure may be sterilized (e.g., using heat, radiation, ethylene oxide, hydrogen peroxide, etc.) to ensure they are safe for use in patients, and the methods described herein may include sterilization of the associated systems, devices, and apparatus (e.g., using heat, radiation, ethylene oxide, hydrogen peroxide, etc.).

[0016] The term “associated” is used herein in accordance with its broad and ordinary meaning. For example, where a first feature, element, component, device, or member is described as “associated” with a second feature, element, component, device, or member, such description should be understood to indicate that the first feature, element, component, device, or member is physically coupled, attached, connected, integrated, at least partially embedded, or otherwise physically related to the second feature, element, component, device, or member, whether directly or indirectly.

[0017] Figure 1 shows an embodiment of a medical access system 200 deployed within the heart 1 to provide access to the pericardial space of the heart 1. The medical access system 200 may provide percutaneous access to the pericardial space. The medical access system 200 may comprise an outer needle assembly 202 and an inner needle assembly 230. The inner needle assembly 230 may comprise an inner needle shaft 232 extending distally from an inner needle hub 270. In some cases, the inner needle assembly 230 may include a pre-loaded portion within the delivery lumen 218 of the outer needle assembly 202 while the outer needle assembly 202 is advancing into the pleural cavity through an access point on the chest. In some cases, the outer needle assembly 202 may be inserted percutaneously through an access point on the chest. The inner needle shaft 232 may be configured to be slidably positioned within the outer needle assembly 202. At least a portion of the outer needle shaft 210 may be advanced into the pleural cavity. After the outer needle shaft 210 is positioned as desired, the inner needle assembly 230 can be deployed to provide access to the pericardial space.

[0018] In some cases, the insertion of the medical access system 200 into the thoracic cavity can be performed at various insertion sites in the chest. In some cases, access into the thoracic cavity can be performed using a subxiphoid, para-, or apical approach. For example, FIG. 1 shows entering the thoracic cavity using a subxiphoid approach using the medical access system 200. In some cases, the medical access system 200 can be used to access the cardiothoracic cavity using a subxiphoid access approach for entry into the pericardial space. In some cases, access to the cardiothoracic cavity can be made to enter the pericardial space using a transapical approach. The methods and devices described herein primarily refer to access to the cardiac pericardial space, but it will be understood that the methods and / or devices can be applied to the controlled access of any other blood vessel, cardiac chamber, lumen, and / or organ.

[0019] FIG. 2 is a side view of the medical access system 200 including an outer needle assembly 202 and an inner needle assembly 230. The outer needle assembly 202 can include an outer needle hub 204 and an outer needle shaft 210 extending distally from the outer needle hub 204. The delivery lumen 218 of the outer needle assembly 202 can extend through the outer needle hub 204 and the outer needle shaft 210. The inner needle assembly 230 can include an inner needle shaft 232 extending distally from an inner needle hub 270. At least a portion of the inner needle shaft 232 can be configured to be slidably received within the delivery lumen 218 of the outer needle assembly 202. The inner needle shaft 232 can include a narrower distal portion 238 and a wider portion 236 proximal to the narrower distal portion 238. A transition segment 250 can extend between the narrower distal portion 238 and the wider portion 236, for example, joining the narrower distal portion 238 and the wider portion 236. A transverse dimension, such as the outer diameter of the narrower distal portion 238, can be shorter than the dimension of the wider portion 236. The transverse dimension can be perpendicular or substantially perpendicular to the longitudinal axis of the inner needle shaft 232.

[0020] In some cases, the wider portion 236 may include the proximal portion 234 of the inner needle shaft 232. In some cases, the wider portion 236 may include a portion of the inner needle shaft 232 that is proximal to the transition segment 250 and distal to the distal end 274 of the inner needle hub 270. For example, the wider portion 236 may extend from the transition segment 250 to the proximal end 240 of the inner needle shaft 232. In some cases, the wider portion 236 may extend from the proximal end 240 of the inner needle shaft 232 to the proximal end 252 of the transition segment 250. For example, the distal end 248 of the wider portion 236 may be adjacent to and in contact with the proximal end 252 of the transition segment 250. In some cases, the outer diameter of the wider portion 236 may be uniform or substantially uniform along its longitudinal dimension, including from the proximal end 240 to the distal end 248 of the inner needle shaft 232.

[0021] In some cases, the narrower distal portion 238 may include a portion of the inner needle shaft 232 distal to the transition segment 250. In some cases, the narrower distal portion 238 may extend from the transition segment 250 to the distal end 242 of the inner needle shaft 232, for example, from the distal end 254 of the transition segment 250 to the distal end 242 of the inner needle shaft 232. For example, the proximal end 246 of the narrower distal portion 238 may be adjacent to and in contact with the distal end 254 of the transition segment 250. The distal end 242 of the inner needle shaft 232 may be the distal end of the narrower distal portion 238. In some cases, the distal end 242 may include at least a sharp portion configured to penetrate tissue and allow the inner needle shaft 232 to advance through the tissue. For example, the distal end 242 may be configured to puncture the pericardium, allowing the inner needle shaft 232 to advance into the pericardial space. In some cases, the side wall 258 of the inner needle shaft 232 may define the shaft having a narrower distal portion 238, a wider portion 236, and a transition segment 250 extending distally from the wider portion 236 to the narrower distal portion 238. In some cases, the outer diameter of the distal narrower portion 238 may be uniform or substantially uniform along its longitudinal dimension, including from the proximal end 246 to the distal end 242.

[0022] In some cases, the narrower distal portion 238 may include lateral dimensions such as an outer diameter smaller than that of a standard gauge needle. In some cases, the lateral dimensions of the narrower distal portion 238 may be the same as or similar to those of a micropuncture needle. In some cases, the narrower distal portion 238 may include a micropuncture needle. In some cases, the lateral dimensions of the narrower distal portion 238 may be the same as or similar to those of a 22 gauge (G) needle. The narrower distal portion 238 may include a 22 gauge (G) micropuncture needle. In some cases, the lateral dimensions of the narrower distal portion 238 may be smaller than those of a standard gauge needle, including those between those of a standard gauge needle and those of a micropuncture needle such as an 18 gauge (G) needle and a 22 gauge (G) micropuncture needle. In some cases, the lateral dimensions of the narrower distal portion 238 range from approximately 0.6 mm to approximately 1.2 mm, and may include approximately 0.7 mm to approximately 1.1 mm and approximately 0.7 mm to approximately 1.0 mm.

[0023] In some cases, the transition segment 250 may have a tapered transition segment. In some cases, the transition segment 250 may have an external contour. The inner needle shaft 232 may have a tapered transition section that includes a contour tapering from a wider portion 236 to a narrower distal portion 238. The transition segment 250 may taper along a direction parallel or substantially parallel to the longitudinal axis of the inner needle shaft 232, such as extending from the proximal end 252 to the opposite portion on the distal end 254. For example, the transition segment 250 may have a tapered contour extending from the wider portion 236 to the narrower distal portion 238. The tapered contour may include a linear taper and / or a curved taper, including a protruding curve and / or a recessed curve. In some cases, the transition segment 250 may taper linearly or substantially linearly from the proximal end 252 to the distal end 254. In some cases, the transition segment 250 may narrow along a concave or protruding curve from the proximal end 252 to the distal end 254.

[0024] In some cases, the transition segment 250 may extend circumferentially around the inner needle shaft 232. In some cases, a tapered transition segment may extend circumferentially around the inner needle shaft 232. The tapered transition may be uniform or not uniform around the inner needle shaft 232. In some cases, the transition segment 250 may form a truncated cone shape, as shown in Figure 2. In some cases, the transition segment 250 may have an uneven tapered contour around the circumference of the inner needle shaft 232, such as having a larger and / or steeper taper on the portion having the distal opening 256 than on the opposing portion. Alternatively, the transition segment 250 may extend only partially around the circumference of the inner needle shaft 232. For example, a tapered transition segment may extend only partially around the circumference of the inner needle shaft 232. In some cases, the transition segment 250, including a tapered transition segment, may extend around the first circumferential portion of the inner needle shaft 232. The second circumferential portion of the inner needle shaft 232 may include a linear or substantially linear contour. For example, the inner needle shaft 232 may have a linear or substantially linear contour around the second partial circumferential portion, which includes the tapered transition segment around the first partial circumferential portion and the remaining portion around the inner needle shaft. In some cases, the wider portion 236 and the narrower distal portion 238 may have a linear or substantially linear contour when they merge, join, and / or integrate together around the remaining portion around the inner needle shaft 232.

[0025] The internal needle assembly 230 may comprise a first delivery lumen 260 and a second delivery lumen 262. The first delivery lumen 260 may include a portion extending through a narrower distal portion 238. For example, the first delivery lumen 260 may include a portion extending through the internal needle shaft 232, including from the proximal end 240 of the internal needle shaft 232 to the distal end 242 of the internal needle shaft 232. The first delivery lumen 260 may be in fluid communication with the distal end opening 244 at the distal end 242 of the internal needle shaft 232, such as the distal end of the narrower distal portion 238. In some cases, the first delivery lumen 260 may extend through the internal needle hub 270 and the internal needle shaft 232 to the distal end 242 of the internal needle shaft 232. The second delivery lumen 262 may include a portion extending through the wider portion 236 of the inner needle shaft 232. In some cases, the second delivery lumen 262 may include a portion extending from the proximal end 240 of the inner needle shaft 232 to the distal opening 256 associated with the transition segment 250. In some cases, the second delivery lumen 262 may extend through the inner needle hub 270 and a portion of the inner needle shaft 232 proximal to the narrower distal portion 238, for example, through the wider portion 236 of the inner needle shaft 232, to the distal opening 256. In some cases, the distal opening 256 may be on the transition segment 250, such as extending through a sidewall portion 258 of the inner needle shaft 232 that defines the transition segment 250. As described herein, the transition segment 250 may comprise a tapered transition segment. In some cases, the distal opening 256 may be on the tapered transition segment. For example, the distal opening 256 may be located on a tapered portion of the transition segment 250. Figure 2 shows the transition segment 250, which includes a tapered contour, extending circumferentially around the inner needle shaft 232. In an alternative example, the first circumferential portion may comprise the transition segment 250 having a tapered contour and a second circumferential portion having a linear or substantially linear contour. The distal opening 256 may be located on the first circumferential portion, including the tapered portion.The first and second delivery lumens 260, 262 may include at least a portion that extends along each other and / or is parallel to or substantially parallel to the longitudinal axis of the inner needle shaft 232. In some cases, the inner needle shaft 232 may be a dual lumen shaft.

[0026] The first and / or second delivery lumens 260, 262 may be configured to allow the advancement of each guidewire through them. In some cases, at least a portion of a guidewire having lateral dimensions such as a diameter of approximately 0.25 mm to 0.50 mm, including approximately 0.35 mm to 0.45 mm, may be advanced through the first and / or second delivery lumens 260, 262. In some cases, at least a portion of a guidewire having a diameter of approximately 0.010 inches to 0.020 inches, including approximately 0.014 inches to 0.018 inches, may be advanced through the first and / or second delivery lumens 260, 262. In alternative cases, the guidewire may have a diameter larger or smaller than the diameters described herein. For example, a first guidewire 290 may be deployed through a first delivery lumen 260. A second guidewire 294 may be deployed through a second delivery lumen 262. Guidewire deployment may facilitate secure access to the pericardial space. After secure access to the pericardial space is achieved, medical therapy may be delivered through the first delivery lumen 260 or the second delivery lumen 262, including injection of any number of different fluids into and / or withdrawal from the pericardial space. In some cases, imaging contrast dyes may be delivered. In some cases, one or more therapeutic agents may be delivered.

[0027] Referring again to Figure 2, the outer needle assembly 202 may comprise a delivery lumen 218 extending through the outer needle assembly 202, including passing through the outer needle hub 204 and the outer needle shaft 210. The outer needle assembly 202 may comprise an outer needle shaft 210 extending distally from the outer needle hub 204. In some cases, the outer needle shaft 210 may have lateral dimensions, such as the same as or similar to the outer diameter of a standard gauge needle. These lateral dimensions may be perpendicular or substantially perpendicular to the longitudinal axis of the outer needle shaft 210. In some cases, the outer needle shaft 210 may have lateral dimensions that are the same as or similar to those of a standard gauge needle. In some cases, the outer diameter of the outer needle shaft 210 may be uniform or substantially uniform along the longitudinal dimension of the outer needle shaft 210, such as from the proximal end 212 to the distal end 214. In some cases, the distal end 214 may include at least a sharp portion that penetrates the tissue and is configured to allow the outer needle shaft 210 to advance through the tissue, enabling the outer needle shaft 210 to navigate through the percutaneous access pathway. For example, the side wall 220 of the outer needle shaft 210 may define a shaft having the same or similar outer diameter along the entire length, or substantially the entire length, of the outer needle shaft 210 distal to the distal end 208 of the outer needle hub 204. In some cases, the outer needle shaft 210 may include a standard gauge needle. In some cases, the outer needle shaft may have lateral dimensions, such as outer diameter, that are the same as or similar to those of an 18 gauge (G) needle. The outer needle shaft 210 may include an 18 gauge (G) needle. In some cases, the lateral dimensions of the outer needle shaft 210 may be larger than those of a standard gauge needle, such as an 18 gauge (G) needle. In some cases, the outer needle shaft 210 may include lateral dimensions such as an outer diameter of approximately 1.0 mm to approximately 1.6 mm, including approximately 1.0 mm to approximately 1.5 mm and approximately 1.2 mm to approximately 1.4 mm.

[0028] At least a portion of the inner needle shaft 232 may be slidably positioned within the delivery lumen 218 of the outer needle assembly 202. As described further herein, the inner needle shaft 232 may be pre-loaded into the outer needle assembly 202 while navigating the medical access system 200 to a target position. The inner needle assembly 230 may then be configured to advance relative to the outer needle assembly 202, targeting the positioning of at least a portion of the narrower distal portion 238 distal to the distal end 214 of the outer needle assembly within the cardiac pericardial space. In some cases, the inner needle shaft 232 may be advanced until the distal end 274 of the inner needle hub 270 contacts the proximal end 206 of the outer needle hub 204. If the internal needle assembly 230 overshoots the cardiac pericardial space, for example, if the narrower distal portion 238 is positioned within a cardiac chamber, the internal needle assembly 230 may advance further to position the distal opening 256 on the transition segment 250 within the cardiac pericardial space. After the narrower distal portion 238 is positioned within an adjacent cardiac ventricle or atrium, the internal needle assembly 230 may be further advanced to position the distal opening 256 within the cardiac pericardial space.

[0029] In some cases, the medical access system 200 may be configured to provide controlled advancement and / or retraction of the inner needle assembly 230 relative to the outer needle assembly 202. For example, the outer needle assembly 202, such as the outer needle hub 204, may include an advance and retraction control unit 222 that contacts the inner needle shaft 232 and is configured to provide controlled advancement and / or retraction of the inner needle shaft 232. In some cases, the advance and retraction control unit 222 may provide progressive advancement and / or retraction of the inner needle shaft 232, such as a ratchet mechanism. For example, an operator, such as a surgeon, may rotate a knob, dial, and / or lever of the advance and retraction control unit 222 to gradually advance and / or retract the inner needle shaft 232 relative to the outer needle assembly 202, which includes the outer needle shaft 210. In some cases, the forward and backward control unit 222 may be configured to provide visual (e.g., a numbered scale), auditory, and / or tactile feedback, including after each incremental forward and / or backward movement, such as every millimeter (mm) of movement. In some cases, at least a portion of the outer needle shaft 210 and / or the inner needle shaft 232 may be radiopaque. For example, the outer needle shaft 210 and the inner needle shaft 232 may be radiopaque to allow visualization of their respective positions and to facilitate the placement of each shaft. In some cases, radiopaque needle shafts with smaller diameters may be more difficult to visualize. The forward and backward control unit 222 may facilitate controlled forward and / or backward movement of the inner needle shaft 232, including a micropuncture needle.

[0030] In some cases, the inner needle hub 270 may include a first port 278 configured to mate with a first syringe (not shown), such as on the proximal end 272 of the inner needle hub 270. In some cases, the first port 278 may be in fluid communication with a first delivery lumen 260. For example, while at least a portion of the narrower distal portion 238 of the first syringe is located in the pericardial space, the first syringe may draw pericardial fluid from the pericardial space through the first delivery lumen 260 and the first port 278. Alternatively, if at least a portion of the narrower distal portion 238 is located in the cardiac ventricle or cardiac atrium, the first syringe may draw blood from the cardiac ventricle or cardiac atrium through the first delivery lumen 260 and the first port 278. In some cases, the inner needle hub 270 may include a second port 280 configured to mate with a second syringe (not shown). The second port 280 can be in fluid communication with the second delivery lumen 262. For example, the second syringe can draw pericardial fluid from the pericardial space through the distal opening 256 and the second delivery lumen 262, while the second distal opening 256 is positioned within the pericardial space. In some cases, the first syringe can be fitted with the first port 278 while the distal end opening 244 is in the cardiac ventricle or atrium and the distal opening 256 is in the pericardial space, thereby allowing blood to be drawn by the first syringe. In some cases, enabling the withdrawal of pericardial fluid and / or blood by the syringe can facilitate confirmation of the position of the inner needle shaft 232.

[0031] In some cases, the inner needle shaft 232 may include an electrode 264 configured to provide an electrical signal indication when the electrode 264 and / or the shaft 232 are in contact with the cardiac myocardium. The electrode 264 may be configured to provide electrical feedback indicating that the inner needle shaft 232 has been inserted further than a desired extent. For example, the electrode 264 may include at least a portion related to the distal end 242 of the inner needle shaft 232, for example, on and / or coupled to the distal end 242 of the inner needle shaft 232. The electrode 264 may be configured to provide an electrical signal indication when the distal end 242 and / or the portion of the inner needle shaft 232 including the electrode 264 is in contact with the cardiac myocardium. The electrode 264 may be in electrical communication with an output on the inner needle assembly 230, such as an output contact 276 of the inner needle hub 270, which is configured to provide electrical measurements to an electrocardiogram device. The electrocardiogram can receive measurements through output contacts 276, such as via one or more lead wires. For example, ST elevation displayed by the user interface of the electrocardiogram device may indicate to the operator that the inner needle shaft 232 has been inserted too far.

[0032] In some cases, the outer needle assembly 202 may include electrodes (not shown) configured to provide an electrical signal indication when in contact with cardiac myocardium. For example, the outer needle shaft 210, including its distal end 214, may include electrodes having one or more characteristics of electrodes 264 of the inner needle assembly 230. The outer needle hub 204 may include output contacts (not shown) having one or more characteristics of output contacts 276 of the inner needle assembly 230.

[0033] In some cases, the inner needle assembly 230 may include one or more pressure sensors (not shown). For example, one or more pressure sensors may be associated with each portion of the proximal portion 234, including the proximal end 240 and / or the distal end 242 of the inner needle shaft 232. The pressure sensors may be coupled to the pressure sensor outputs on the inner needle hub 270, including mechanically and / or electrically. The pressure sensors may also enable readings of the pressure to which the inner needle shaft 232 is exposed, for example, to determine the position of the inner needle shaft 232, thereby facilitating the navigation of the inner needle shaft 232 to a target position.

[0034] Figures 3A and 3B are side cross-sectional views showing the deployment of a first guidewire 290 into the pericardial space 3 of the heart 1 using the medical access system 200, as described with reference to Figure 2. As described herein, at least a portion of the inner needle shaft 232 may be slidably positioned within the delivery lumen 218 of the outer needle assembly 202 while the outer needle shaft 210 is navigated to the target position. For example, the inner needle shaft 232 may be pre-loaded within the delivery lumen 218 of the outer needle assembly 202, at its distal end 242 within the delivery lumen 218, and proximal to the distal end 214 of the outer needle shaft 210. In some cases, the navigation of the outer needle shaft 210 to the target position may be acoustically guided and / or assisted using fluoroscopy. The distal end 214 of the outer needle shaft 210 may be positioned proximal and / or adjacent to the outer surface of the pericardium 2. In some cases, the distal end 214 may be positioned away from and not in contact with the outer surface of the pericardium 2. For example, the distal end 214 may be maintained away from the outer surface of the pericardium 2 while the inner needle shaft 232 is deployed through the distal end opening 216 of the outer needle shaft 210. Alternatively, the distal end 214 of the outer needle shaft 210 may be on and in contact with the outer surface of the pericardium 2 while the inner needle shaft 232 is deployed through the distal end opening 216 of the outer needle shaft 210.

[0035] After the outer needle shaft 210 is desiredly positioned, the inner needle assembly 230 can advance relative to the outer needle assembly 202 to position a portion of the inner needle shaft 232 through the distal end opening 216 of the outer needle shaft 210. Referring to Figure 3A, the narrower distal portion 238 can be inserted through the pericardium 2 and positioned within the pericardial space 3 so that the distal end opening 244 of the inner needle shaft 232 can be positioned within the pericardial space 3. The advancement of the inner needle shaft 232 through the delivery lumen 218 of the outer needle shaft 210 can be completely friction-free or reduced, facilitating controlled advancement of the inner needle shaft 232 to position the narrower distal portion 238 within the pericardial space 3. The outer needle shaft 210 can provide support and / or guidance to the inner needle shaft 232 during its advancement. The advancement of the inner needle shaft 232, which is slidably positioned within the outer needle assembly 202, can provide improved tactile feedback for the controlled insertion of the narrower distal portion 238 into the pericardial space 3.

[0036] Referring to Figure 3B, after the narrower distal portion 238 is desirablely positioned, and after the narrower distal portion 238 is positioned within the pericardial space 3, the first guidewire 290 can be deployed through the first delivery lumen 260. A portion of the first guidewire 290 can be advanced into the pericardial space 3 through the first delivery lumen 260 of the inner needle assembly 230 and through the distal end opening 244 positioned within the pericardial space 3. For example, the distal portion 292 of the first guidewire 290 can be positioned within the pericardial space 3. The first guidewire 290 can be deployed to facilitate the firm positioning of the narrower distal portion 238 within the pericardial space 3.

[0037] Figures 4A and 4B are side cross-sectional views showing the deployment of a first guidewire 290 and a second guidewire 294 into the pericardial space 3 of the heart 1 into the cardiac chamber 5 using the medical access system 200 described with reference to Figure 2. The cardiac chamber 5 may be a cardiac ventricle or cardiac atrium. Referring to Figure 4A, the narrower distal portion 238 is shown as being positioned within the cardiac chamber 5. Positioning the narrower distal portion 238 within the pericardial space 3 may be difficult as described herein. The narrower distal portion 238 may overshoot the pericardial space 3 and be advanced further than desired. A portion of the narrower distal portion 238 may be unintentionally positioned through the myocardium 4 such that the distal end opening 244 of the distal end 242 of the inner needle shaft 232 is positioned within the cardiac chamber 5. For example, at least a portion of the inner needle shaft 232 may be pre-loaded into the outer needle assembly 202, such as while the outer needle shaft 210 is being advanced along an anatomical pathway. The portion of the inner needle shaft 232 may be carried within the delivery lumen 218 of the outer needle assembly 202 such that the distal end 242 of the inner needle shaft 232 may be proximal to the distal end 214 of the outer needle shaft 210. The distal end 214 of the outer needle shaft 210 may be proximal to or on the externally oriented surface of the pericardium 2. The inner needle assembly 230 may then advance relative to the outer needle assembly 202 to position the portion of the inner needle shaft 232 through the distal end opening 216 of the outer needle shaft 210.

[0038] If the narrower distal portion 238 of the inner needle shaft 232 overshoots the intended target location within the pericardial space 3, the inner needle shaft 232 may advance further relative to the outer needle shaft 210 to position at least a portion of the transition segment 250 within the pericardial space 3. Referring to Figure 4B, the inner needle assembly 230 may be advanced further to position the distal opening 256 on the transition segment 250 within the pericardial space 3. The inner needle shaft 232 does not need to retract. For example, the position of the outer needle shaft 210 can be maintained while the inner needle shaft 232 is advancing. Bleeding from myocardial puncture by the narrower distal portion 238 may be reduced compared to that caused by a larger hole needle and / or a wider portion 236.

[0039] In some cases, the first guidewire 290 can be deployed into the cardiac chamber 5 through the first delivery lumen 260. A portion of the first guidewire 290 can be advanced into the cardiac chamber 5 through the first delivery lumen 260 of the inner needle assembly 230 and through a distal end opening 244 located in the cardiac chamber 5. For example, the distal portion 292 of the first guidewire 290 can be located in the cardiac chamber 5. The second guidewire 294 can be deployed through the second delivery lumen 262 of the inner needle assembly 230 so that a portion of the second guidewire 294 can be positioned in the pericardial space 3. A portion of the second guidewire 294 can be advanced into the pericardial space 3 through the second delivery lumen 262 and through a distal opening 256 on a transition segment 250 located in the pericardial space 3. The distal portion 296 of the second guidewire 294 can be located in the pericardial space 3. Positioning the second guidewire 294 within the pericardial space 3 may facilitate the fixation of the distal opening 256 within the pericardial space 3. The first guidewire 290 may be deployed to facilitate the firm positioning of the narrower distal portion 238 within the cardiac chamber 5, thereby facilitating the firm positioning of the distal opening 256 within the pericardial space 3. Alternatively, the first guidewire 290 may not be deployed. For example, the second guidewire 294 may be deployed into the pericardial space 3 through the second delivery lumen 262 without deploying the first guidewire 290 into the cardiac chamber 5 through the first delivery lumen 260.

[0040] Figure 5 is a process flow diagram showing an embodiment of procedure 500 for accessing the cardiac pericardial space. Block 502 may involve providing an outer needle assembly comprising an outer needle hub and an outer needle shaft extending distally from the outer needle hub. A delivery lumen may extend through the outer needle assembly, including the outer needle hub and the outer needle shaft. Block 504 may involve providing an inner needle assembly comprising an inner needle shaft having a narrower distal portion, a wider portion proximal to the narrower distal portion, and a transition between the narrower distal portion and the wider portion. At least a portion of the inner needle shaft may be slidably received within the delivery lumen of the outer needle assembly. Block 506 may involve advancing the inner needle shaft relative to the outer needle shaft to position at least a portion of the narrower distal portion distal to the distal end of the outer needle shaft.

[0041] In some cases, advancing the inner needle shaft relative to the outer needle shaft may involve positioning at least a portion of the narrower distal portion within the cardiac pericardial space. For example, distally positioning at least a portion of the narrower distal portion of the distal end of the outer needle shaft may involve positioning at least a portion of the narrower distal portion within the cardiac pericardial space.

[0042] In some cases, the process may involve advancing the lateral needle assembly to a target position. For example, advancing the lateral needle assembly to a target position may involve advancing the lateral needle shaft along an anatomical pathway to position the distal end of the lateral needle shaft at a desired position. In some cases, advancing the lateral needle assembly to a target position may involve positioning the distal end of the lateral needle shaft proximal to and / or adjacent to the outer surface of the pericardium. Advancing the lateral needle assembly to a target position may involve positioning the distal end of the lateral needle shaft away from and not in contact with the outer surface of the pericardium. Alternatively, advancing the lateral needle assembly to a target position may involve positioning the distal end of the lateral needle shaft on and in contact with the outer surface of the pericardium.

[0043] In some cases, at least a portion of the inner needle shaft may be slidably received within the delivery lumen of the outer needle assembly, for example, pre-loaded within the delivery lumen, while the outer needle assembly is advanced along an anatomical pathway. For example, the outer needle shaft may be advanced along an anatomical pathway to position its distal end at the target location, while at least a portion of the inner needle shaft is pre-loaded through the delivery lumen of the outer needle assembly. The distal end of the inner needle shaft may be within the delivery lumen, such as proximal to the distal end of the outer needle shaft, while the inner needle shaft is pre-loaded within the outer needle assembly. Alternatively, the inner needle shaft may be advanced through the delivery lumen of the outer needle assembly after the outer needle assembly has been positioned at the target location.

[0044] In some cases, advancing the inner needle shaft relative to the outer needle shaft may involve maintaining the position of the outer needle shaft while the inner needle shaft is deployed through the distal end opening of the outer needle shaft. For example, the distal end of the outer needle shaft may be maintained in its position, either spaced away from, on, or in contact with the outer surface of the pericardium, while the inner needle shaft is deployed through the distal end opening of the outer needle shaft.

[0045] In some cases, providing an internal needle assembly may include providing a first delivery lumen that extends through the internal needle shaft and is in fluid communication with a distal end opening on the distal end of the internal needle shaft. The distal end of the internal needle shaft may be the distal end of a narrower distal portion. Providing an internal needle assembly may include providing a second delivery lumen that extends through a wider portion of the internal needle shaft and is in fluid communication with a distal opening on a transition segment of the internal needle shaft. In some cases, advancing the internal needle shaft relative to the external needle shaft may include positioning the distal end opening on the distal end of the internal needle shaft within the cardiac pericardial space. In some cases, the process may involve deploying a portion of the first guidewire through the first delivery lumen into the cardiac pericardial space while the narrower distal portion and at least a portion of the distal end opening are positioned within the cardiac pericardial space. For example, at least a portion of the first guidewire can advance through the first delivery lumen and distal end opening to position the portion of the first guidewire within the cardiac pericardial space. Positioning a portion of the first guidewire within the cardiac pericardial space can facilitate the secure positioning of the narrower distal portion within the cardiac pericardial space.

[0046] Alternatively, advancing the inner needle shaft relative to the outer needle shaft may include positioning at least a portion of the narrower distal portion within the cardiac chambers, including the cardiac ventricles or atria, for example, positioning the distal end opening on the distal end of the inner needle shaft within the cardiac ventricles or atria. In some cases, advancing the inner needle shaft may include overshooting the pericardial space so that a portion of the inner needle shaft is unintentionally positioned within the cardiac ventricles or atria adjacent to the pericardial space. For example, the narrower distal portion may be advanced into the cardiac ventricles or atria. In some cases, advancing the inner needle shaft relative to the outer needle shaft may include positioning the distal opening on the transition segment within the cardiac pericardial space. The process may involve advancing the inner shaft until the distal opening on the transition segment is positioned within the cardiac pericardial space, if the distal end opening of the narrower distal portion overshoots the cardiac pericardial space. The position of the lateral needle shaft can be maintained while the narrower distal portion advances, including while positioning the distal opening on the transition segment within the cardiac pericardial space.

[0047] In some cases, the process may involve deploying a second guidewire into the cardiac pericardial space while the distal opening on the transition segment is positioned within the cardiac pericardial space. For example, the process may involve advancing a portion of the second guidewire into the pericardial space through a second delivery lumen and the distal opening on the transition segment, while the distal opening on the transition can be positioned within the cardiac pericardial space. In some cases, the process may involve deploying a first guidewire into the cardiac ventricle or atrium through the first delivery lumen while at least a portion of the narrower distal portion is positioned within the cardiac ventricle or atrium. For example, a portion of the first guidewire may be advanced into the cardiac ventricle or atrium through the first delivery lumen, while the distal opening on the distal end of the narrower distal portion is positioned within the cardiac ventricle or atrium, and the distal opening on the transition segment is positioned within the cardiac pericardial space. In some cases, the first guidewire may not be deployed into the cardiac ventricle or atrium.

[0048] In some cases, the process may involve fitting a first syringe into a first port on the inner needle hub, the first port being in fluid communication with a first delivery lumen of the inner needle assembly, allowing the first syringe to draw pericardial fluid from the cardiac pericardial space, while a narrower distal portion of the inner needle shaft and its distal end opening are positioned within the pericardial space, or at least a portion of the narrower distal portion of the inner needle shaft and its distal end opening are positioned within the cardiac ventricle or atrium, allowing blood to be drawn from the cardiac ventricle or atrium. In some cases, the process may involve fitting a second syringe into a second port on the inner needle hub, the second port being in fluid communication with a second delivery lumen of the inner needle assembly, allowing the second syringe to draw pericardial fluid from the pericardial space while its distal opening on the transition segment is positioned within the pericardial space. In some cases, one or more delivery lumens of an internal needle assembly can be used to deliver one or more drugs to target locations, including target sites within the pericardial space. For example, contrast solutions may be delivered to the pericardial space through one or more delivery lumens of an internal needle assembly, for instance, to facilitate imaging procedures. In some cases, the process may involve contacting the distal end electrode of the narrower distal portion with the cardiac myocardium. Contacting the electrode with the cardiac myocardium may result in the generation of an electrical signal indicating that the internal needle assembly has been overinserted.

[0049] Figure 6 is a side view of one embodiment of a medical access system 600 configured to provide access to the pericardial space. The medical access system 600 may comprise an outer needle assembly 602 and an inner needle assembly 630. The outer needle assembly 602 may comprise an outer needle hub 604 and an outer needle shaft 610 extending distally from the outer needle hub 604. The inner needle assembly 630 may comprise an inner needle shaft 632 extending distally from the inner needle hub 650. In some cases, the outer needle assembly 602 may comprise a first delivery lumen 618 and a second delivery lumen 620 extending through the outer needle assembly 602. In some cases, the first and second delivery lumen 618, 620 may extend along each other through the outer needle assembly 602. At least a portion of the inner needle shaft 632 may be configured to be slidably received within the first delivery lumen 618 extending through the outer needle assembly 602. As will be described in more detail herein, in some cases the guidewire may be advanced through a second delivery lumen 620. Alternatively, the outer needle assembly 602 may have a single delivery lumen extending through the needle assembly, so that the guidewire may be advanced through the same delivery lumen in which the inner needle shaft 632 is slidably positioned.

[0050] In some cases, the inner needle shaft 632 may have uniform or substantially uniform lateral dimensions, such as diameter. These lateral dimensions may be perpendicular or substantially perpendicular to the longitudinal axis of the inner needle shaft 632. For example, the inner needle shaft 632 may have the same or similar outer diameter along its entire longitudinal dimension, or substantially along its entire length, such as the length of the inner needle shaft 632. The inner needle shaft 632 may have the same outer diameter along its entire length, extending distal to the distal end 654 of the inner needle hub 650, including from the proximal end 634 of the inner needle shaft 632 to the distal end 636. These longitudinal dimensions may be parallel or substantially parallel to the longitudinal axis of the inner needle shaft 632. In some cases, the side wall 642 of the inner needle shaft 632 may define a shaft having the same or similar outer diameter along the entire length, or substantially the entire length, of the inner needle shaft 632 distal to the distal end 654 of the inner needle hub 650.

[0051] In some cases, the inner needle shaft 632 may contain a needle. In some cases, the lateral dimensions of the inner needle shaft 632, such as the outer diameter, may be smaller than those of a standard gauge needle. In some cases, the inner needle shaft 632 may have lateral dimensions, such as the same or similar outer diameter, as that of a micropuncture needle. In some cases, the inner needle shaft 632 may contain a micropuncture needle. In some cases, the outer diameter of the inner needle shaft 632 may be the same as or similar to that of a 22 gauge (G) needle. The inner needle shaft 632 may contain a 22 gauge (G) micropuncture needle. In some cases, the lateral dimensions of the inner needle shaft 632 may be smaller than those of a standard gauge needle, including those of a standard gauge needle, and those of a micropuncture needle, such as an 18 gauge (G) needle and a 22 gauge (G) micropuncture needle. In some cases, the lateral dimensions of the inner needle shaft 632 can be approximately 0.6 mm to 1.2 mm, including approximately 0.7 mm to 1.1 mm and approximately 0.7 mm to 1.0 mm.

[0052] In some cases, the outer needle shaft 610 may have uniform or substantially uniform lateral dimensions, such as diameter, along its entire longitudinal dimension, such as the length of the outer needle shaft 610, or substantially along its entire longitudinal dimension. The lateral dimensions may be perpendicular or substantially perpendicular to the longitudinal axis of the outer needle shaft 610. The longitudinal dimensions may be parallel or substantially parallel to the longitudinal axis of the outer needle shaft 610. For example, the outer needle shaft 610 may have the same or similar outer diameter along its entire length extending distal to the distal end 608 of the outer needle hub 604, such as from the proximal end 612 to the distal end 614 of the outer needle shaft 610. In some cases, the distal end 614 may include at least a portion that is sharp and configured to puncture tissue, allowing the outer needle shaft 610 to advance through the tissue, thereby enabling navigation of the outer needle shaft 610 through a percutaneous access pathway. As described further herein, the distal end 614 of the outer needle shaft 610 may be advanced into the pericardial space. The distal end 614 may be configured to allow puncture of the pericardium and insertion of a portion of the outer needle shaft 610 into the pericardial space. In some cases, the side wall 622 of the outer needle shaft 610 may define a shaft having the same or similar outer diameter along the entire length, or substantially the entire length, of the outer needle shaft 610, distal to the distal end 608 of the outer needle hub 604. In some cases, the outer needle shaft 610 may include a needle. In some cases, the lateral dimensions of the outer needle shaft 610, such as the outer diameter, may be the same as or similar to the dimensions of a standard gauge needle. In some cases, the outer needle shaft 610 may include a standard gauge needle. In some cases, the outer needle shaft 610 may have the same or similar lateral dimensions as an 18 gauge (G) needle. The outer stylus shaft 610 may include an 18-gauge (G) stylus. In some cases, the lateral dimension of the outer stylus shaft 610 may be larger than the dimensions of a standard gauge stylus, such as an 18-gauge (G) stylus.In some cases, the outer needle shaft 610 may include lateral dimensions such as an outer diameter of approximately 1.0 mm to approximately 1.6 mm, including, for example, approximately 1.0 mm to approximately 1.5 mm and approximately 1.2 mm to approximately 1.4 mm.

[0053] In some cases, the internal needle assembly 630 may be configured to advance relative to the external needle assembly 602 to deploy the internal needle assembly 630. A portion of the internal needle shaft 632 may be positioned distal to the distal end 614 of the external needle shaft 610 and configured to be positioned within the pericardial space. For example, the internal needle shaft 632 may advance relative to the external needle shaft 610 to position its distal end opening 638 within the pericardial space at its distal end 636. In some cases, the distal end 636 may include at least a portion that is sharp and configured to allow the internal needle shaft 632 to advance through tissue, such as by puncturing tissue and the pericardium to allow the internal needle shaft 632 to advance into the pericardial space. In some cases, the internal needle shaft 632 may be advanced until the distal end 654 of the internal needle hub 650 contacts the proximal end 606 of the external needle hub 604. The distal end opening 638 can be in fluid communication with the delivery lumen 640, which extends through the inner needle assembly 630. Positioning the distal end opening 638 of the inner needle shaft 632 into the pericardial space can be difficult, as described herein. If a portion of the inner needle shaft 632 is unintentionally advanced beyond the pericardial space, such as by being deployed through the myocardium into a cardiac chamber such as the ventricle or atrium, the outer needle assembly 602 may advance relative to the inner needle assembly 630 to position a portion of the outer needle shaft 610 into the pericardial space. If the inner needle shaft 632 overshoots into the pericardial space, as described in further detail herein, the outer needle shaft 610 may advance relative to the inner needle shaft 632 to maintain the position of the inner needle shaft 632 while positioning the distal end opening 616 of the outer needle shaft 610 into the pericardial space. In some cases, a portion of the guidewire can be advanced into the pericardial space through a second delivery lumen 620 and a distal end opening 616. After secure access to the pericardial space is achieved, medical treatment can be delivered through the inner needle shaft 632 or the outer needle shaft 610, including injection of any number of different fluids into and / or withdrawal from the pericardial space. In some cases, imaging contrast dyes can be delivered.

[0054] In some cases, the outer needle hub 604 may have a first port 626 configured to mate with a first syringe (not shown). In some cases, the first port 626 may be in fluid communication with the delivery lumen of the outer needle assembly 602, such as a first and / or second delivery lumen 618, 620. For example, the first syringe can draw pericardial fluid from the pericardial space through the first and / or second delivery lumen 618, 620 and the access opening 628 of the first port 626, while the distal end opening 616 of the distal end 614 of the outer needle shaft 610 is positioned in the pericardial space. In some cases, a second syringe (not shown) may be mate with a second port 658, such as on the proximal end 652 of the inner needle hub 650 of the inner needle assembly 630, and may be configured to draw fluid through the delivery lumen 640 of the inner needle assembly 630. For example, a second syringe can draw blood through the delivery lumen 640 and the second port 658, while the distal end opening 638 of the distal end 636 of the inner needle shaft 632 is positioned within the cardiac ventricle or atrium. Alternatively, a second syringe can draw pericardial fluid through the delivery lumen 640 and the second port 658, while the distal end opening 638 of the distal end 636 of the inner needle shaft 632 is positioned within the pericardial space. In some cases, one or more delivery lumens of the outer needle assembly 602 and / or the inner needle assembly 630 can be used to deliver a solution to a target location, including a target location within the pericardial space. For example, a contrast agent solution can be delivered into the pericardial space through one or more delivery lumens, for example, to facilitate imaging procedures. In some cases, one or more therapeutic agents can be delivered through one or more delivery lumens.

[0055] In some cases, the inner needle shaft 632 may include an electrode 644, and the inner needle hub 650 may include an output contact 656 having one or more characteristics of an electrode 264 and an output contact 276, respectively, as shown with reference to Figure 2. In some cases, the outer needle assembly 602, such as the outer needle hub 604, may include an advance and retraction control unit 624 having one or more characteristics of an advance and retraction control unit 222, as shown with reference to Figure 2. In some cases, at least a portion of the outer needle shaft 610 and / or the inner needle shaft 632 may be radiopaque. For example, the outer needle shaft 610 and the inner needle shaft 632 may be radiopaque to allow visualization of their respective positions and to facilitate the arrangement of each shaft. In some cases, radiopaque needle shafts with smaller diameters may be more difficult to visualize. The advance and retraction control unit 624 may facilitate controlled advance and / or retraction of the inner needle shaft 632, including a micropuncture needle.

[0056] In some cases, the outer needle assembly 602 may include electrodes (not shown) configured to provide an electrical signal indication when in contact with cardiac myocardium. For example, the outer needle shaft 610, including its distal end 614, may include electrodes having one or more characteristics of electrode 264 as described with reference to Figure 2. The outer needle hub 604 may include output contacts (not shown) having one or more characteristics of output contacts 276 as described with reference to Figure 2. In some cases, the inner needle assembly 630 may include one or more pressure sensors (not shown). For example, one or more pressure sensors may be associated with each part of the proximal portion, including the proximal end 634 and / or distal end 636 of the inner needle shaft 632. The pressure sensors may be coupled to pressure sensor outputs on the inner needle hub 650, including mechanical and / or electrical connections. For example, one or more pressure sensors and / or pressure sensor outputs may have one or more characteristics, as described with reference to Figure 2.

[0057] Figures 7A and 7B are side cross-sectional views of an embodiment of accessing the cardiac pericardial space using a medical access system 600, described with reference to Figure 6. Figure 7A is a side cross-sectional view of the medical access system 600, having an inner needle shaft 632 positioned within a cardiac chamber 5. The cardiac chamber 5 may be a cardiac ventricle or cardiac atrium. At least a portion of the inner needle shaft 632 may be pre-loaded within an outer needle assembly 602. For example, while the outer needle shaft 610 is advanced along an anatomical pathway, a portion of the inner needle shaft 632 may be within a second delivery lumen 620, and the distal end 636 of the inner needle shaft 632 may be proximal to the distal end 614 of the outer needle shaft 610. The outer needle shaft 610, carrying the inner needle shaft 632, may be advanced to a target position, for example, by positioning the distal end 614 of the outer needle shaft 610 proximal to or on an externally oriented surface of the pericardium 2 of the heart 1. The internal needle assembly 630 can be advanced through the pericardium 2, targeting the positioning of the distal end 636 of the internal needle shaft 632 within the pericardial space 3. Positioning the distal end 636 of the internal needle shaft 632 within the pericardial space 3, as described herein, can be difficult. The internal needle shaft 632 may overshoot the pericardial space 3 and be advanced further than desired. Referring to Figure 7A, a portion of the internal needle shaft 632 may unintentionally be positioned through the myocardium 4 within the cardiac chamber 5 of the heart 1.

[0058] Referring to Figure 7B, even if the inner needle shaft 632 overshoots the intended target position within the pericardial space 3, the inner needle shaft 632 does not need to retract. In some cases, the inner needle shaft 632 may remain in place. The outer needle assembly 602 may be advanced to position the outer needle shaft 610 within the pericardial space 3. For example, the outer needle shaft 610 may be advanced relative to the inner needle shaft 632 so that the distal end opening 616 on the distal end 614 of the outer needle shaft 610 is positioned within the pericardial space 3. Bleeding from puncturing the myocardium 5 with the inner needle shaft 632 may be reduced compared to that caused by a larger hole needle. The advancement of the outer needle shaft 610 may be at least partially guided by the inner needle shaft 632.

[0059] In some cases, one or more guidewires may be deployed through the lumen of the outer needle assembly and / or the inner needle assembly to facilitate secure positioning of the medical access system 600. For example, a first guidewire 660 may be deployed into the cardiac pericardial space 3 through the second delivery lumen 620 of the outer needle assembly 602. A portion of the first guidewire 660 may be advanced through the second delivery lumen 620 and the distal end opening 616 of the outer needle shaft 610 so as to be positioned within the pericardial space 3. For example, the distal portion 662 of the first guidewire 660 may be positioned within the pericardial space 3. In some cases, a second guidewire 664 may be deployed into the cardiac chamber 5 through the delivery lumen 640 of the inner needle assembly 630. In some cases, a portion of the second guidewire 664 may be advanced through the delivery lumen 640 of the inner needle assembly 630 and the distal end opening 638 of the distal end 636 of the inner needle shaft 632, and positioned within the cardiac chamber 5. For example, the distal portion 666 of the second guidewire 664 may be positioned within the cardiac chamber 5. In some cases, at least a portion of the first guidewire 660 and / or the second guidewire 664 may have lateral dimensions such as a diameter of approximately 0.25 mm to approximately 0.50 mm, including approximately 0.35 mm to approximately 0.45 mm. In some cases, at least a portion of the first guidewire 660 and / or the second guidewire 664 may have a diameter of approximately 0.010 inches to approximately 0.020 inches, including approximately 0.014 inches to approximately 0.018 inches.

[0060] Figure 8 is a process flow diagram illustrating an embodiment of procedure 800 for accessing the cardiac pericardial space. Block 802 may involve providing an outer needle assembly comprising an outer needle hub and an outer needle shaft extending distally from the outer needle hub. A first delivery lumen may extend through the outer needle hub and the outer needle shaft. Block 804 may involve providing an inner needle assembly comprising an inner needle shaft having at least a portion configured to be slidably received within the first delivery lumen of the outer needle assembly. Block 806 may involve advancing the inner needle shaft relative to the outer needle shaft and positioning the distal portion of the inner needle shaft within the cardiac ventricle. In an alternative example, the distal portion of the inner needle shaft may be positioned within the cardiac atrium. In block 808, the process may involve advancing the outer needle shaft relative to the inner needle shaft, positioning the distal portion of the outer needle shaft within the cardiac pericardial space, while the distal portion of the inner needle shaft is positioned within the cardiac ventricle. In some cases, the process may involve advancing the outer needle shaft relative to the inner needle shaft, positioning the distal portion of the outer needle shaft within the cardiac pericardial space, while the distal portion of the inner needle shaft is positioned within the cardiac atrium.

[0061] In some cases, the process may involve advancing the lateral needle assembly to a target position. For example, advancing the lateral needle assembly to a target position may involve advancing the lateral needle shaft along an anatomical pathway to position the distal end of the lateral needle shaft at a desired position. In some cases, advancing the lateral needle assembly to a target position may involve positioning the distal end of the lateral needle shaft proximal to and / or adjacent to the outer surface of the pericardium. Advancing the lateral needle assembly to a target position may involve positioning the distal end of the lateral needle shaft away from and not in contact with the outer surface of the pericardium. Alternatively, advancing the lateral needle assembly to a target position may involve positioning the distal end of the lateral needle shaft on and in contact with the outer surface of the pericardium.

[0062] In some cases, at least a portion of the inner needle shaft may be slidably positioned within the first delivery lumen of the outer needle assembly, for example, pre-loaded within the first delivery lumen, while the outer needle assembly is advanced along an anatomical pathway. For example, the outer needle shaft may be advanced along an anatomical pathway to position its distal end at the target, while at least a portion of the inner needle shaft is pre-loaded through the first delivery lumen of the outer needle assembly. The distal end of the inner needle shaft may be located within the first delivery lumen, such as proximal to the distal end of the outer needle shaft, while the inner needle shaft is pre-loaded within the outer needle assembly. Alternatively, the inner needle shaft may be advanced through the first delivery lumen of the outer needle assembly after the outer needle assembly has been positioned at the target.

[0063] In some cases, advancing the inner needle shaft relative to the outer needle shaft may involve maintaining the position of the outer needle shaft while the inner needle shaft is being deployed through the distal end opening of the outer needle shaft. For example, the distal end of the outer needle shaft may be maintained in its position, either spaced away from, on, or in contact with the outer surface of the pericardium, while the inner needle shaft is being deployed through the distal end opening of the outer needle shaft.

[0064] In some cases, the process may involve deploying the first guidewire into the cardiac pericardial space through a second delivery lumen of the outer needle shaft. For example, deploying the first guidewire may involve advancing a portion of the first guidewire into the cardiac pericardial space through the second delivery lumen and the distal end opening of the outer needle shaft. In some cases, the process may involve deploying the second guidewire through a delivery lumen that extends into the cardiac ventricle or atrium via the inner needle assembly. For example, deploying the second guidewire may involve advancing a portion of the second guidewire into the cardiac ventricle or atrium through the delivery lumen and the distal end opening of the inner needle shaft. Positioning the first guidewire into the cardiac pericardial space and / or the second guidewire into the cardiac ventricle or atrium may facilitate secure positioning of the outer needle shaft and / or the inner needle shaft.

[0065] In some cases, the process may involve fitting a first syringe into a first port on the outer needle hub, the first port being in fluid communication with first and / or second delivery lumens of the outer needle assembly, allowing the first syringe to draw pericardial fluid from the cardiac pericardial space, while the distal portion of the outer needle shaft is positioned within the cardiac pericardial space. In some cases, the process may involve fitting a second syringe into a second port on the inner needle hub, the second port being in fluid communication with a delivery lumen extending through the inner needle assembly, allowing the second syringe to draw blood from the cardiac ventricle or atrium, while the distal portion of the inner needle shaft is positioned within the cardiac ventricle or atrium. In some cases, one or more delivery lumens of the inner needle assembly and / or the outer needle assembly may be used to deliver one or more drugs to a target location, such as a target location within the pericardial space. For example, contrast agent solutions may be delivered to the pericardial space, for example, to facilitate imaging procedures. In some cases, one or more therapeutic agents may be delivered.

[0066] Description of additional examples A list of examples is provided below, each of which may include an embodiment of any of the other embodiments disclosed herein. Furthermore, any embodiment of any of the embodiments described above may be implemented in any of the numbered embodiments provided below.

[0067] Example 1: A medical access system comprising an inner needle assembly, including an inner needle shaft configured to be at least partially slidably positioned within the delivery lumen of an outer needle assembly. The inner needle shaft may include a narrower distal portion, a wider portion proximal to the narrower distal portion, and a transition segment between the narrower distal portion and the wider portion. The inner needle shaft may include a first delivery lumen within the inner needle shaft, extending from the proximal end of the inner needle shaft to the distal end opening of the distal end of the narrower distal portion, and a second delivery lumen within the inner needle shaft, extending from the proximal end to the distal opening on the transition segment.

[0068] Example 2: Any embodiment of this specification, in particular the system described in Example 1, wherein the transition segment extends circumferentially around the inner needle shaft.

[0069] Example 3: Any embodiment of this specification, in particular the system according to Example 1 or 2, wherein the transition segment extends around a first circumferential portion of the inner needle shaft, and the second circumferential portion of the inner needle shaft includes a linear contour.

[0070] Example 4: Any embodiment of this specification, in particular the systems described in Examples 1 to 3, comprising a tapered transition segment having a contour that narrows from a wider portion to a narrower distal portion.

[0071] Example 5: Any embodiment of this specification, in particular the system described in Example 4, wherein the distal opening on the transition segment is located on a tapered transition segment.

[0072] Example 6: Any embodiment of the system described herein, particularly those described in Examples 1 to 5, wherein the inner needle assembly is configured to advance relative to the outer needle assembly and to perform one of the following: positioning at least a portion of the narrower distal portion of the distal end of the outer needle assembly distally and within the cardiac pericardial space, or positioning the distal opening on the transition segment distal to the outer needle assembly and within the cardiac pericardial space.

[0073] Example 7: Any embodiment of this specification, particularly the system described in Examples 1 to 6, including an electrode, wherein the distal end of the inner needle shaft is configured to provide an electrical signal indication when the electrode is in contact with cardiac myocardium.

[0074] Example 8: Any embodiment of the system according to this specification, particularly the systems according to Examples 1 to 7, wherein the internal needle assembly comprises an internal needle hub, and the internal needle shaft is configured to extend distally from the internal needle hub, and the internal needle hub comprises a first port configured to engage with a first syringe, the first port being in fluid communication with a first delivery lumen, so that the first syringe can draw pericardial fluid from the pericardial space, and at least a portion of the narrower distal portion is positioned in the pericardial space or in the blood from the cardiac ventricle, and at least a portion of the narrower distal portion is positioned within the cardiac ventricle.

[0075] Example 9: Any embodiment of the system according to this specification, particularly the systems described in Examples 1 to 8, wherein the internal needle assembly comprises an internal needle hub, an internal needle shaft configured to extend distally from the internal needle hub, and the internal needle hub comprises a second port configured to mate with a second syringe, the second port being in fluid communication with a second delivery lumen, allowing the second syringe to draw pericardial fluid from the pericardial space while the distal opening on the transition segment is in the pericardial space.

[0076] Example 10: Any embodiment of this specification, in particular the system described in Examples 1 to 9, wherein the narrower distal portion of the internal needle shaft includes a micropuncture needle.

[0077] Example 11: Any embodiment of this specification, in particular the system described in Examples 1 to 10, wherein the first needle shaft comprises an 18 gauge (G) needle.

[0078] Example 12: Any embodiment of the system described herein, particularly the systems described in Examples 1 to 11, wherein the first delivery lumen and the second delivery lumen are configured to slidably receive a guidewire having a diameter of approximately 0.014 inches to approximately 0.018 inches.

[0079] Example 13: A method for accessing the cardiac pericardial space, the method comprising: providing an outer needle assembly comprising an outer needle hub, an outer needle shaft extending distally from the outer needle hub, and a delivery lumen extending through the outer needle hub and the outer needle shaft; and providing an inner needle assembly comprising an inner needle shaft having at least a portion configured to be slidably positioned within the delivery lumen of the outer needle assembly. The inner needle shaft may include a narrower distal portion, a wider portion proximal to the narrower distal portion, and a transition segment between the narrower distal portion and the wider portion. The method may include advancing the inner needle shaft relative to the outer needle shaft to position at least a portion of the narrower distal portion distal to the distal end of the outer needle shaft.

[0080] Example 14: Any embodiment of this specification, particularly the method of Example 13, wherein advancing the inner needle shaft relative to the outer needle shaft positions at least a portion of the narrower distal portion within the cardiac pericardial space.

[0081] Example 15: Any embodiment of this specification, particularly the method of Example 13, comprising advancing the inner needle shaft relative to the outer needle shaft to position at least a portion of the narrower distal portion within the cardiac ventricle and positioning the distal opening on the transition segment within the cardiac pericardial space.

[0082] Example 16: Any embodiment of this specification, particularly the method of Examples 13-15, to provide an internal needle assembly comprising: a first delivery lumen in the internal needle shaft extending from the proximal end of the internal needle shaft to a distal end opening on the distal end of a narrower distal portion; and a second delivery lumen in the internal needle shaft extending from the proximal end to a distal opening on a transition segment.

[0083] Example 17: Any embodiment of this specification, particularly the method of Example 16, further comprising advancing a portion of the first guidewire into the cardiac pericardial space through the first delivery lumen and the distal end opening on the narrower distal portion, while at least a portion of the narrower distal portion is positioned within the cardiac pericardial space.

[0084] Example 18: Any embodiment of this specification, particularly the method of Example 16, further comprising advancing a portion of the second guidewire into the pericardial space through the second delivery lumen and the distal opening on the transition segment, wherein the distal opening on the transition segment is located within the cardiac pericardial space.

[0085] Example 19: The method of any embodiment of this specification, in particular the method of Example 18, further comprising advancing a third guidewire through the first delivery lumen into the cardiac ventricle while the distal opening on the transition segment is positioned in the cardiac pericardial space and the distal end opening on the distal end of the narrower distal portion is positioned in the cardiac ventricle, on the other hand.

[0086] Example 20: Providing an internal needle assembly comprising an internal needle hub and an internal needle shaft extending distally from the internal needle hub, wherein the method further comprises fitting a first syringe onto a first port portion on the internal needle hub, the first port being in fluid communication with a first delivery lumen, the first syringe enabling the first syringe to draw pericardial fluid from the cardiac pericardial space, with at least a portion of the narrower distal portion positioned in the pericardial space or in the blood from the cardiac ventricle, and at least a portion of the narrower distal portion positioned within the cardiac ventricle, any embodiment of this specification, particularly the method of Example 16.

[0087] Example 21: Providing an internal needle assembly comprises an internal needle hub and an internal needle shaft extending distally from the internal needle hub, the method further comprising fitting a second syringe into a second port on the internal needle hub, the second port being in fluid communication with a second delivery lumen, thereby enabling the second syringe to draw pericardial fluid from the pericardial space, while the distal opening on the transition segment is located within the pericardial space, any embodiment of this specification, particularly the method of Example 16.

[0088] Example 22: Any embodiment of this specification, particularly the method of Examples 13-21, further comprising bringing the distal end electrode of a narrower distal portion into contact with cardiac myocardium.

[0089] The above methods can be implemented on living animals or in simulations (on corpses, corpse hearts, anthropomorphic ghosts, simulators (where body parts, hearts, tissues, etc., are simulated)).

[0090] Example 23: A method for accessing the cardiac pericardial space, the method comprising providing an outer needle assembly comprising an outer needle hub, an outer needle shaft extending distally from the outer needle hub, and a first delivery lumen extending through the outer needle hub and the outer needle shaft, and providing an inner needle assembly comprising an inner needle shaft having at least a portion configured to be slidably received within the first delivery lumen of the outer needle assembly, the method comprising advancing the inner needle shaft relative to the outer needle shaft to position the distal portion of the inner needle shaft within the cardiac ventricle, and while the distal portion of the inner needle shaft is positioned within the cardiac ventricle, advancing the outer needle shaft relative to the inner needle shaft to position the distal portion of the outer needle shaft within the cardiac pericardial space.

[0091] Example 24: Any embodiment of this specification, particularly the method of Example 23, further comprising advancing a portion of the first guidewire through the second delivery lumen of the outer needle shaft into the cardiac pericardial space.

[0092] Example 25: Any embodiment of this specification, particularly the method of Example 23 or 24, further comprising advancing a portion of the second guidewire through the delivery lumen, extending it through the inner needle assembly, and positioning the second guidewire within the cardiac ventricle.

[0093] Example 26: Any embodiment of the method according to this specification, particularly the method according to Examples 23-25, further comprising fitting a first syringe into a first port on an outer needle hub, wherein the first port is in fluid communication with at least one of a first delivery lumen and a second delivery lumen of the outer needle assembly, thereby enabling the first syringe to draw pericardial fluid from the cardiac pericardial space, while the distal portion of the outer needle shaft is positioned within the cardiac pericardial space.

[0094] Example 27: Providing an internal needle assembly comprises an internal needle hub and an internal needle shaft extending distally from the internal needle hub, the method further comprising fitting a second syringe into a second port on the internal needle hub, the second port being in fluid communication with a delivery lumen extending through the internal needle assembly, the second syringe enabling the drawing of blood from the cardiac ventricle, while the distal portion of the internal needle shaft is positioned within the cardiac ventricle, any embodiment of this specification, particularly the method of Examples 23-26.

[0095] The above methods can be implemented on living animals or in simulations (on corpses, corpse hearts, anthropomorphic ghosts, simulators (where body parts, hearts, tissues, etc., are simulated)).

[0096] Depending on the embodiment, certain actions, events, or functions of any of the processes or algorithms described herein may be performed in a different order, added, merged, or completely excluded. Therefore, in a particular embodiment, not all described actions or events are necessary for the practice of the process.

[0097] In particular, conditional language used herein, such as “can,” “could,” “might,” “may,” and “e.g.,” is intended in its ordinary sense unless otherwise stated or understood differently in the context in which it is used, and is generally intended to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not. Therefore, such conditional language is not generally intended to imply that configurations, elements, and / or steps are required in any way in one or more embodiments, or that one or more embodiments necessarily include, with or without input or prompting by the author, logic for determining whether these configurations, elements, and / or steps are included or performed in any particular embodiment. Terms such as “comprising,” “including,” and “having” are synonymous and are used in their ordinary sense, comprehensively and in an open-ended manner, without excluding additional elements, features, functions, actions, etc. Furthermore, the term "or" is used in its inclusive sense (and not its exclusive sense), for example, when used to connect a list of elements, so that the term "or" can mean one, some, or all of the elements in the list. Connecting phrases such as "at least one of X, Y, and Z" are understood in context to be used to generally convey that an item, term, element, etc., may be any of X, Y, or Z, unless otherwise specified. Thus, such connecting phrases are not generally intended to imply that a particular embodiment requires the presence of at least one of X, at least one of Y, and at least one of Z, respectively.

[0098] In the above descriptions of the embodiments, it should be understood that various features are sometimes grouped together in a single embodiment, figure, or description for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various embodiments of the invention. However, this method of disclosure should not be construed as reflecting the intention that any claim requires more features than expressly described in that claim. Furthermore, any component, feature, or step illustrated and / or described in a particular embodiment of this specification may be applied to or used in conjunction with any other embodiment. Moreover, no component, feature, step, or group of components, features, or steps is required or essential to each embodiment. Accordingly, the scope of the invention of the present invention disclosed and claimed below should not be limited by the particular embodiments described above, and should be determined solely by a fair reading of the following claims.

[0099] It should be understood that certain ordering terms (e.g., “first,” or “second”) may be provided for ease of reference and do not necessarily imply physical properties or order. Therefore, when used herein, ordering terms (e.g., “first,” “second,” “third,” etc.) used to modify elements such as structures, components, and operations do not necessarily indicate the priority or order of an element relative to any other element, but rather may generally distinguish an element from another element having a similar or identical name (except for the use of ordering terms). In addition, when used herein, the indefinite articles ("a" and "an") may indicate “one or more” rather than “one.” Furthermore, actions performed “on the basis” of a condition or event may also be performed on the basis of one or more other conditions or events not explicitly stated.

[0100] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those commonly understood by those skilled in the art in the field to which the exemplary examples belong. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and it is understood that they should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0101] Spatially relative terms such as “outside,” “inside,” “upside,” “downside,” “up,” “vertical,” and “horizontal,” and similar terms may be used herein to facilitate explanation and to describe the relationship between one element or component and another, as shown in the drawings. It is understood that spatially relative terms are intended to encompass different orientations of a device in use or operation, in addition to the orientation depicted in the drawings. For example, if a device shown in the drawings is turned over, a device positioned “below” or “directly below” another device may be positioned “above” another device. Thus, the exemplary term “below” includes both the lower and upper positions. Devices may also be oriented in other directions, and therefore, spatially relative terms may be interpreted differently depending on the orientation.

[0102] Unless otherwise explicitly stated, comparative terms and / or quantitative terms such as “less,” “more,” “greater,” and “same kind” are intended to encompass equivalent concepts. For example, “less” can mean not only “less” in the strictest mathematical sense, but also “less than or equal to.”

Claims

1. A medical access system, An inner needle assembly comprising an inner needle shaft configured to be at least partially slidably positioned within the delivery lumen of an outer needle assembly, wherein the inner needle shaft is A narrower distal portion, a wider portion proximal to the narrower distal portion, and a transitional segment between the narrower distal portion and the wider portion. A medical access system comprising: a first delivery lumen within the inner needle shaft extending from the proximal end of the inner needle shaft to the distal end opening of the narrower distal portion; and a second delivery lumen within the inner needle shaft extending from the proximal end to the distal opening on the transition segment.

2. The system according to claim 1, wherein the transition segment extends circumferentially around the inner needle shaft.

3. The system according to claim 1, wherein the transition segment extends around a first circumferential portion of the inner needle shaft, and the second circumferential portion of the inner needle shaft includes a linear contour.

4. The system according to any one of claims 1 to 3, wherein the transition segment comprises a tapered transition segment having a contour that narrows from a wider portion to a narrower distal portion.

5. The system according to claim 4, wherein the distal opening on the transition segment is located on the tapered transition segment.

6. The inner needle assembly is configured to be advanced relative to the outer needle assembly, and one of the following: Position at least a portion of the narrower distal portion toward the distal end of the outer needle assembly and within the cardiac pericardial space. The system according to any one of claims 1 to 3, wherein the distal opening on the transition segment is positioned distal to the outer needle assembly and into the cardiac pericardial space.

7. The system according to any one of claims 1 to 3, wherein the distal end of the inner needle shaft is configured to provide an electrical signal indication when the electrode is in contact with cardiac myocardium.

8. A system according to any one of claims 1 to 3, wherein the internal needle assembly comprises an internal needle hub, the internal needle shaft is configured to extend distally from the internal needle hub, the internal needle hub comprises a first port configured to engage with a first syringe, the first port is in fluid communication with a first delivery lumen, enabling the first syringe to draw pericardial fluid from the pericardial space, at least a portion of the narrower distal portion is located in the pericardial space or in the blood from the cardiac ventricle, and at least a portion of the narrower distal portion is located within the cardiac ventricle.

9. A system according to any one of claims 1 to 3, wherein the internal needle assembly comprises an internal needle hub, the internal needle shaft is configured to extend distally from the internal needle hub, the internal needle hub comprises a second port configured to engage with a second syringe, the second port is in fluid communication with the second delivery lumen, and the second syringe is configured to draw pericardial fluid from the pericardial space while the distal opening on the transition segment is within the pericardial space.

10. The system according to any one of claims 1 to 3, wherein the narrower distal portion of the inner needle shaft includes a micropuncture needle.

11. The system according to any one of claims 1 to 3, wherein the first needle shaft comprises an 18 gauge (G) needle.

12. The system according to any one of claims 1 to 3, wherein the first delivery lumen and the second delivery lumen are configured to slidably receive a guidewire having a diameter of about 0.014 inches to about 0.018 inches.

13. A method for accessing the cardiac pericardial space, wherein the method is To provide an external needle assembly comprising an external needle hub, an external needle shaft extending distally from the external needle hub, and a delivery lumen extending through the external needle hub and the external needle shaft, To provide an inner needle assembly comprising an inner needle shaft having at least a portion configured to be slidably positioned within the delivery lumen of the outer needle assembly, wherein the inner needle shaft is The narrower distal portion, It comprises a wider portion proximal to the narrower distal portion, and a transition segment between the narrower distal portion and the wider portion. A method comprising advancing the inner needle shaft relative to the outer needle shaft so that at least a portion of the narrower distal portion is positioned distal to the distal end of the outer needle shaft.

14. The method according to claim 13, wherein advancing the inner needle shaft relative to the outer needle shaft includes positioning at least a portion of the narrower distal portion within the cardiac pericardial space.

15. The inner needle shaft is advanced relative to the outer needle shaft. To position at least a portion of the narrower distal portion into the cardiac ventricle, The method according to claim 13, comprising positioning the distal opening on the transition segment within the cardiac pericardial space.

16. To provide the aforementioned inner needle assembly, the following is achieved: A first delivery lumen within the inner needle shaft extends from the proximal end of the inner needle shaft to the distal end opening on the distal end of the narrower distal portion, The method according to any one of claims 13 to 15, comprising providing the inner needle assembly, which includes a second delivery lumen in the inner needle shaft extending from the proximal end to a distal opening on the transition segment.

17. The method according to claim 16, further comprising advancing a portion of a first guidewire into the cardiac pericardial space through the first delivery lumen and the distal end opening on the narrower distal portion, wherein at least a portion of the narrower distal portion is positioned within the cardiac pericardial space.

18. The method involves advancing a portion of the second guidewire into the pericardial space through the second delivery lumen and the distal opening on the transition segment, such that the distal opening on the transition segment is positioned within the cardiac pericardial space. The method according to claim 16, further comprising advancing a third guidewire through the first delivery lumen into the cardiac ventricle while the distal opening on the transition segment is located within the cardiac pericardial space and the distal end opening on the distal end of the narrower distal portion is located within the cardiac ventricle.

19. Providing the inner needle assembly includes providing an inner needle assembly comprising an inner needle hub and an inner needle shaft extending distally from the inner needle hub, and the method is The first syringe is fitted to the first port portion on the inner needle hub, wherein the first port is in fluid communication with the first delivery lumen, allowing the first syringe to draw pericardial fluid from the cardiac pericardial space, while at least a portion of the narrower distal portion is positioned in the pericardial space or blood from the cardiac ventricle, while at least a portion of the narrower distal portion is positioned within the cardiac ventricle. The method according to claim 16, comprising fitting a second syringe into a second port on the inner needle hub, wherein the second port is in fluid communication with the second delivery lumen, enabling the second syringe to draw pericardial fluid from the pericardial space while the distal opening on the transition segment is positioned within the pericardial space.

20. The method according to any one of claims 13 to 15, further comprising bringing the electrode at the distal end of the narrower distal portion into contact with cardiac myocardium.

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