Patent Application
20200338316
The present invention relates to a vascular access system. In particular, the present invention is directed to a vascular access system for access of any part of the vascular system (e.g., artery, vein, chamber, etc.). In a particular application, the present invention relates to a system and method for vascular access via the radial artery for treating the brain, heart or anywhere else in the body.
Numerous vascular (e.g., neurovascular and cardiovascular) treatments and diagnoses employ a therapeutic or diagnostic catheter, for example, a guiding catheter and a balloon catheter, advanced through a vessel of the body. Rather than introducing the therapeutic or diagnostic catheter directly into the body (i.e., bareback), an introducer sheath commonly serves as a portal to protect tissues and vessels at the access site from trauma and damage during advancement and manipulation of the catheter or other ancillary devices. The introducer sheath is commonly part of a conventional introducer assembly or kit. Referring to
The introducer sheath 120 comprises a tube segment of biocompatible material having a lumen defined longitudinally therethrough. An inner diameter of the lumen of the introducer sheath is sized according to the largest outer diameter catheter to be accommodated therein. The dilator 110 disposed at the distal end of the introducer system or kit 100 is received within the lumen of the introducer sheath 120 and enlarges the puncture opening of the skin at the access site or point on the body sufficient to permit access therethrough of the introducer sheath 120. Dilator 110 is a relatively short, stiff, thick-walled section of catheter having a tapered distal end (typically forming a cone) that enlarges a passage through the body tissues. The hemostasis valve 125 comprising part of the introducer assembly 100 allows interchangeability of ancillary devices with minimal, or no, loss of blood.
During the procedure the introducer sheath 120 is introduced into a puncture site of the body with the dilator 110 positioned within the lumen thereof proximate at its distal end. The tapered design of the dilator 110 (with its distal end having the smallest diameter and increasing in diameter to its opposite proximal end having the largest diameter) enlarges or expands the passage through the body tissue surrounding the puncture site sufficient to accommodate the outer diameter of the introducer sheath 120. Once the introducer sheath 120 has been properly positioned proximate the access site of the body, the dilator 110 may be withdrawn proximally through the lumen of the introducer sheath 120. A catheter and/or other ancillary devices may thereafter be advanced therethrough the lumen of the introducer sheath 120 and into the vessel until reaching the target site in the body without causing damage to the surrounding body tissues.
The introducer sheath is typically color-coded following accepted industry standards, wherein different colors denote a maximum outer diameter of an ancillary medical device (for example, a catheter) accepted or accommodated in the lumen of the introducer sheath. Red color introducer sheath is able to accommodate or accept a 4F guide catheter; gray color introducer sheath is able to accommodate or accepts a 5F guide catheter; green color introducer sheath is able to accommodate or accept a 6F guide catheter; orange color introducer sheath is able to accommodate or accept a 7F guide catheter; blue color introducer sheath is able to accommodate or accepts a 8F guide catheter; black color introducer sheath is able to accommodate or accept a 9F guide catheter; purple color introducer sheath is able to accommodate or accept a 10F guide catheter; yellow color introducer sheath is able to accommodate or accept a 11F guide catheter.
By way of illustrative example, Table 1 below is illustrative of several conventional size guide catheters and corresponding conventional introducer sheath dimensions.
Heretofore, the femoral artery located in the groin was the preferred access site (i.e., puncture point) at which the conventional introducer assembly 100 in
The present invention is directed to a vascular access system and method with an improved introducer sheath design that when combined with a conventional size guide catheter to form an assembled unit introduced simultaneously through the access site overcomes the aforementioned problems.
An aspect of the present invention is directed to a vascular access system and method, preferably a radial artery access system and method, with an improved introducer sheath design that when combined with a conventional size guide catheter to form an assembled unit introduced simultaneously through the access site overcomes the aforementioned problems associated with conventional introducer sheaths.
Another aspect of the present invention relates to a vascular access system including an assembled integral dedicated unit. The assembled integral dedicated unit includes: an introducer sheath having a proximal end, an opposite distal end and a lumen defined axially therethrough from the proximal end to the distal end. The lumen of the introducer sheath having an inner diameter uniform along an entire length of the introducer sheath from the proximal end to the opposite distal end. Wherein, the introducer sheath has a sidewall distal section, a sidewall proximal section and a sidewall transition section at an interface therebetween. An outer diameter of the sidewall distal section is less than an outer diameter of the sidewall proximal section. The assembled integral dedicated unit further including a guide catheter having a lumen defined axially therethrough from a proximal end to an opposite distal end, wherein the guide catheter is receivable within the lumen of the introducer sheath.
Still another aspect of the present invention is directed to a method for using the vascular access system as described in the preceding paragraph. An access site is penetrated using a needle. An atraumatic guidewire is distally advanced through the needle to a target site a predetermined distance beyond the access site. Maintaining in position the guidewire, the needle is withdrawn from the access site. While the guidewire is maintained in position, the dilator, guide catheter and the introducer sheath are assembled in preparation for introduction through the access site. Specifically, such assembling step involves (i) inserting the cone at the distal end of the dilator into and advancing distally through the lumen of the guide catheter until the cone of the dilator fully emerges from the distal end of the guide catheter; and (ii) while radially supported by the guide catheter, sliding the introducer sheath over the guide catheter to the distal end of the guide catheter adjacent to the cone of the dilator. Then the assembly including the dilator, guide catheter and introducer sheath is back-loaded in a proximal direction starting from a distal end of the assembly with the guidewire. The assembly together as a single unit until the dilator cone is advanced interiorly beyond the access site so that the introducer sheath extends from interiorly of the access site to exteriorly of the access site. Withdrawing the dilator from the access site, the assembled guide catheter and introducer sheath are maintained in position. Lastly, the guide catheter is advanced to the target site, through the axial lumen defined in the introducer sheath, without damaging the access site shielded by the introducer sheath.
Yet another aspect of the present invention is directed to a method for using a vascular access system, as described above. At a desired location, an access site it cut down using a surgical cutting tool (e.g., scalpel). An atraumatic guidewire is advanced distally through the access site to a target site a predetermined distance beyond the access site. While the guidewire is maintained in position, the guide catheter and the introducer sheath are assembled in preparation for introduction through the access site. Specifically, such assembling involves, while radially supported by the guide catheter, sliding the introducer sheath over the guide catheter to the distal end of the guide catheter. The assembly including the guide catheter and introducer sheath are back-loaded in a proximal direction starting from a distal end of the assembly with the guidewire. Then, the assembly together as a single unit is advanced until interiorly beyond the access site so that the introducer sheath extends from interiorly of the access site to exteriorly of the access site. Lastly, the guide catheter is advanced to the target site, through the axial lumen defined in the introducer sheath, without damaging the access site shielded by the introducer sheath.
The foregoing and other features of the present invention will be more readily apparent from the following detailed description and drawings illustrative of the invention wherein like reference numbers refer to similar elements throughout the several views and in which:
The terms “distal” or “proximal” are used in the following description with respect to a position or direction relative to the treating physician or medical interventionalist. “Distal” or “distally” are a position distant from or in a direction away from the physician or interventionalist. “Proximal” or “proximally” or “proximate” are a position near or in a direction toward the physician or medical interventionist. The terms “occlusion”, “clot” or “blockage” are used interchangeably.
The present invention minimizes the occurrence of health complications by providing alternative access points in the vascular system (e.g., via the radial artery) for surgical procedures to the brain, heart and anywhere else in the body while still accommodating conventional size guide catheters (e.g., 6F, 7F, 8F size catheters). By way of illustrative example only, the present invention is shown and described as access via the radial artery. However, the present invention is suitable to provide vascular access anywhere in the vascular system. Referring to
Despite such benefits, the substantially smaller size of the radial artery relative to that of the femoral artery poses a significant restriction on the size of the catheter to be accommodated or accepted therein if a conventional introducer sheath is used. The size of the radial artery varies among individuals based on such factors as sex, diabetes and smoking. Studies have found that the mean inner diameter for men and women of the right radial artery on average is 2.44±0.60 mm, which size may be unable to accommodate conventional introducer sheaths of 7F to 8F catheters.
The introducer sheath maintains a space in the body tissue at the point of entry (e.g., puncture site) sufficient in diameter to accommodate conventional guide catheters of varying diameters (e.g., 6F, 7F, 8F). This requires a relatively large differential clearance between the outer diameter of the introducer sheath and the outer diameter of the guide catheter. Referring to Table 1, the outer diameter of the conventional introducer sheath (6F introducer sheath having an outer diameter of 0.109″/2.7686 mm; 7F introducer sheath having an outer diameter of 0.122″/3.0988 mm; and 8F introducer sheath having an outer diameter of 0.133″/3.3782 mm) is too large to be received in the radial artery. Despite the relatively small diameter of the radial artery, based on body type some individuals may be able to accommodate or accept a 6F guide catheter and associated introducer sheath therein. But, in some people, 7F or 8F guide catheters and their associated conventional introducer sheath in Table 1 may be too large in size to be accommodated or accepted into the radial artery.
The smaller size radial artery in comparison to that of the femoral artery poses substantial challenges in design of the introducer sheath so as not to preclude use of conventional size guide catheters therewith. Irrespective of the reduced size of the access point, e.g., via the radial artery, the novel configuration of the present inventive vascular access system and method accommodate or accept a wide range of conventional size guide catheters (e.g., 6F, 7F, 8F).
A conventional introducer sheath is sequentially introduced into the access site before that of the guide catheter. The sidewall of the conventional introducer sheath must therefore be sufficiently thick to have the requisite radial strength to maintain its shape (e.g., self-supporting) when introduced into the access site following puncture and thereafter to permit the guide catheter to be delivered therethrough.
So that varying size conventional guide catheters (6F, 7F, 8F) may be utilized with the radial artery as an access point, the novel configuration of the present inventive introducer sheath focuses on reducing only a portion its outer diameter by thinning a sidewall distal section (relative to that of a conventional introducer sheath whose sidewall has a uniform thickness along its entire longitudinal length). However, as mentioned in the preceding paragraph, because the conventional introducer sheath is passed through the puncture or access site first, followed sequentially thereafter by the guide catheter, the thinned sidewall distal section or portion of the introducer sheath alone would be unable to structurally support itself. The present inventive radial artery access system overcomes this challenge by configuring the present inventive introducer sheath and guide catheter as an integral dedicated unit (i.e., assembled unit or assembled package) wherein the introducer sheath and guide catheter are introduced through the access site simultaneously (at the same time) as an integral dedicated unit. Because the present inventive introducer sheath and guide catheter are introduced through the access site as an integral dedicated unit (assembled unit or package), the required radial strength of the introducer sheath need not be provided by the introducer sheath itself (i.e., the introducer sheath need not be self-supporting). Rather, the requisite radial strength of the present inventive introducer sheath is supplied by the guide catheter comprising part of the integral dedicated unit.
The sidewall thickness of conventional introducer sheaths is approximately 0.010″ uniformly along its entire longitudinal or axial length. As previously noted, following puncture, such uniform sidewall thickness of the conventional introducer sheath provides the necessary structure to be self-supporting (without any physical structural support by any other component) to allow advancement sequentially and independently thereafter of the guide catheter therethrough. Because the guide catheter and present inventive introducer sheath are simultaneously introduced together through the puncture site as an assembled integral dedicated unit (i.e., single assembled package), the radial strength for the thinner-sidewall distal section 410 of the present inventive introducer sheath 420 is provided by the guide catheter 400 disposed within the lumen 415 of the introducer sheath comprising part of the integral dedicated unit, instead of by the introducer sheath itself. Accordingly, the thinner-sidewall distal section 410 of the present inventive introducer sheath 420 that is introduced into the body through the puncture or access site is no longer self-supporting (absent the structural support provided by the guide catheter disposed therein). In accordance with the present invention, the lumen 415 defined axially therethrough the introducer sheath 420 has an inner diameter IDIS that is uniform along its entire longitudinal length from its proximal end to its opposite distal end. It is only the outer diameter of the present inventive introducer sheath 420 that is non-uniform, that is, the outer diameter OD′IS of its thinner-sidewall distal section 410 is less than the outer diameter ODIS of its thicker-sidewall proximal section 412. In the example illustrated in
One or more of a lubricating fluid, a flushing fluid, or a drug may be delivered in the clearance space “C” between the inner wall of the lumen 415 of the present inventive introducer sheath 420 and the outer surface of the guide catheter 400, by way of an integral port at the proximal section of the introducer sheath. The present inventive introducer sheath is preferably made of a lubricious, biocompatible material such as fluoropolymer, for example, PTFE (e.g., Teflon®).
During the medical procedure, a needle 503 is used by the interventionalist to puncture the skin and penetrate the radial artery at the desired access location or site, typically near the wrist. An atraumatic guidewire 505 (preferably with a flexible/J-shaped tip) is advanced distally through the needle to a targeted position within the radial artery a relatively short distance past the access point, toward the heart, as shown in
The desired size of the guide catheter (e.g., 6F, 7F, 8F) comprising part of the assembled unit may be selected based on such factors as the medical procedure to be performed and ancillary devices to be used. While the present inventive introducer sheath and guide catheter remain in place to prevent injury or damage to body tissue surrounding the access site, one or more ancillary devices may be delivered through the lumen of the guide catheter over the guidewire to the target site. Once the ancillary device is properly positioned at the target site, the guidewire may be proximally withdrawn through the assembled unit and out from the body.
The present inventive vascular access system and method have been described for access of the radial artery. However, the present inventive system and method is suitable for vascular access of a target site within the vascular system (e.g., artery, vein, chamber, etc.) anywhere in the body.
Thus, while there have been shown, described, and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions, substitutions, and changes in the form and details of the systems/devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, it is expressly intended that all combinations of those elements and/or steps that perform substantially the same function, in substantially the same way, to achieve the same results be within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated. It is also to be understood that the drawings are not necessarily drawn to scale, but that they are merely conceptual in nature. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
Every issued patent, pending patent application, publication, journal article, book or any other reference cited herein is each incorporated by reference in their entirety.
