Patent Application
20240009424
Catheters and guidewire devices are commonly used to target specific medical issues in a patient's body. Lesions (e.g., vascular lesions) often require catheters to be moved along narrow blood vessels to reach and embolize the lesions. Typically, adhesive embolization is performed by guiding a microcatheter to the treatment site and then using an adhesive (interchangeably referred to herein as an embolic agent and/or embolic adhesive), typically a cyanoacrylate (e.g., n-BCA) or the product sold under the tradename Onyx (which includes ethylene vinyl-alcohol copolymer (EVOH), dimethyl-sulfoxide (DMSO), and micronized tantalum powder (TA)) to embolize the lesion. For example, this procedure is common when treating lesions in the Middle Meningeal Artery (MMA) during an MMA embolism.
One of the challenges of moving the catheter to the treatment site is the size and pathway of the blood vessels. The blood vessels are often narrow and tortuous, making it difficult to get to the targeted anatomy at issue. Catheters and guidewires sometimes are unable to get to the targeted location or cannot get as close to it as desired. Often, the practitioner must inject the adhesive from a greater than preferred distance to treat the lesion(s).
For example, instead of applying adhesive directly to the embolization site, the practitioner may be required to release adhesive from a more distant point. This requires filling the blood vessel(s) with adhesive until it reaches the target site. This also complicates the already difficult balancing act between getting the adhesive to the target before it polymerizes but also allowing it to polymerize before passing too far down the blood vessel past the target. Also, the additional space within the vessel(s), that otherwise would not have been filled with adhesive had the catheter progressed closer to the target, unnecessarily loses its physiological function. Moreover, the adhesive can be quite expensive, and the additional amount required just to fill the space between the catheter and the target can significantly add to the overall cost of the procedure.
In sum, current medical techniques requiring catheters have multiple variables that can affect the procedure. Some of these variables include the vascular path to reach the targeted anatomy, how the catheter is able to move through that pathway, the type of adhesive used and its properties, and other medical complications that could arise. Accordingly, there is a long felt and ongoing need for improved catheters that minimize the number of variables during medical procedures and are able to move easily throughout the vascular system.
The present disclosure relates to a catheter system which includes an outer member and an inner member. Embodiments described herein solve one or more problems related to adhesive embolization that requires the use of a catheter. During adhesive embolization procedures, the closer the catheter can get to the lesion or treatment site, the better the practitioner will be able to manage variables associated with the procedure and the less adhesive will be necessary. The catheter system described herein uses an outer member to initially navigate towards the targeted anatomy and then inserts a second inner member into the outer member and distally past the distal end of the outer member to move even closer to the targeted treatment site.
Embodiments of the catheter system include a stylette which can be inserted into the inner member. This allows for increased rigidity which may aid in navigating the inner member towards the targeted anatomy. That is, the stylette may be configured to have greater bending stiffness and/or columnar stiffness than the inner member. This stylette may include a radiopaque marker, which when inserted can show the position of the stylette and thus the inner member. Some embodiments may include a hydrophilic coating around the stylette, allowing the stylette to slide into the inner member more easily.
In some embodiments, the outer member and stylette may be microfabricated to provide properties such as flexibility when navigating through the vascular system. The outer member and stylette may be fabricated to create circumferentially extending rings and axially extending beams by various cuts of similar of varying depths, widths, and spacing, which may occur with or without angular offsets between successive beams.
Other embodiments may include an inner member where the distal section is selectively detachable. The distal section may detach after injection of an embolic agent. For example, if the distal section of the inner member bonds to the adhesive, the practitioner can beneficially detach the distal section so that the remainder of the inner member and the rest of the catheter system can be safely removed from the patient.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an indication of the scope of the claimed subject matter.
Various objects, features, characteristics, and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings and the appended claims, all of which form a part of this specification. In the Drawings, like reference numerals may be utilized to designate corresponding or similar parts in the various Figures, and the various elements depicted are not necessarily drawn to scale, wherein:
The following detailed description solves one or more of the problems discussed above. As explained in greater detail below, the outer member can be moved towards the targeted anatomy until it cannot readily go any farther. At that point, the inner member may be inserted into the outer member and translated through the outer member until the distal end of the inner member moves distally past the distal end of the outer member, thereby moving the functional distal end of catheter system closer to the targeted anatomy. The closer the catheter system is to the targeted anatomy, the better the practitioner can employ the desired treatment.
For example, when injecting an adhesive, the closer the distal end of the system is to the target anatomy, the less adhesive is necessary to seal the targeted lesion. The adhesive is relatively expensive, and injecting adhesive into the vessels adds variability to the overall procedure. Thus, the ability to navigate the functional distal end of the catheter system closer to the target anatomy (or at least get closer than where conventional systems are used) can beneficially reduce procedure variability and costs, leading to improved patient outcomes.
The elongated member 102 is microfabricated to include circumferentially extending rings 110 and axially extending beams 112. The cut depth, width, and spacing may be consistent or may vary. Embodiments may include one-beam patterns or multiple-beam patterns where the beams are configured in a variety of arrangements. A one beam pattern includes one axially extending member between each successive circumferentially extending ring. Similarly, a two beam pattern includes two axially extending members between each successive circumferentially extending ring. Three beam and more than three beam patterns can be created in a similar fashion. In multiple beam patterns, the beams may be equally or randomly spaced. For example, in a two beam pattern, the two beams may be spaced 180 degrees from one another. In another embodiment, the two beams may be spaced 90 degrees from one another. Various additional cut patterns that may be utilized to form different configurations of rings and beams are disclosed in United States Patent Publication No. 2020/0121308, which is incorporated herein by this reference.
Angular offset arrangements can vary based on the amount of angular offset and/or how often an angular offset is applied between successive beams. Angular offset is the angle between successive beams. By rotating the position of successive beams, preferred bending orientations can be achieved or avoided. For example, a one beam pattern may have a 0 degree offset between successive beams (i.e., no angular offset). This angular offset would align all the beams along a “spine” of the outer member, and would result in preferred bending orientation towards the side where the beams are located (e.g., if the beams are located on a “right” side, the catheter will prefer to bend to the right side). Another example is a one beam pattern with a 180 degree offset between successive beams. A 180 degree angular offset reduces some of the preferred bending seen in the 0 degree offset example. Other embodiments may include other angular offsets therebetween. For example, a two beam pattern may have a 90 degree angular offset while a three beam pattern may have a 60 degree angular offset. As mentioned above, various additional cut patterns that may be utilized to form different configurations of rings and beams are disclosed in United States Patent Publication No. 2020/0121308, which is incorporated herein by this reference.
The embodiment shown in
The length, diameter, and stiffness of the outer member 100 may vary based on application needs. For example, the outer member's elongated member 102 may be about 50 cm to about 200 cm, though shorter or longer lengths may be utilized when appropriate. The diameter of the outer member's lumen may range from about 0.010 inches to 0.100 inches. Possible examples include lumen diameters of 0.013 inches, 0.017 inches, 0.021 inches, 0.027 inches, 0.030 inches, 0.035 inches, 0.038 inches, 0.045 inches, 0.065 inches, 0.086 inches, or a range including any two of the foregoing values as endpoints. The outer catheter 100 is configured to have a transitioning stiffness profile where the proximal section has a higher stiffness and less bending flexibility than the distal section, which has a lower stiffness and higher bending flexibility. The added flexibility in the distal section allows for easier navigation through tortuous vasculature, whereas more proximal sections beneficially provide greater pushability and torquability.
The stiffness profile gradient described above can be created by adjusting the microfabricated elongated member 102 and/or by utilizing different polymer materials. For example, the first microfabricated section 114 may be formed from a first polymer material, the second microfabricated section 116 may be formed from a second polymer material, and the third microfabricated section 118 may be formed of a third polymer material. The hardness and/or modulus of the first polymer material may be greater than the second polymer material, which may be greater than the third polymer material. The differences in polymer hardness and/or modulus thus affects the stiffness of the appropriate sections in the elongated member 102. The microfabricated pattern may also affect the overall stiffness of the elongated member 102. For example, a one beam pattern may have more flexibility than a three beam pattern. The gaps and/or cuts in the microfabricated portions may be filled with another polymer. For example, a soft polymer that allows flexibility (e.g., PEBAX) may fill in the gaps and/or cuts between the rings 110 and beams 112.
The diameter of the elongated member 202 is preferably less than the diameter of the outer member's lumen to allow the inner member 200 to pass through the outer member's lumen. The inner member 200 is shown as having a detachable distal section 206. The joint between the detachable distal section 206 and the more proximal sections of the inner member 200 may include a perforation, groove, thinned section, partial break, intentional weak spot, or other mechanically weakened structure configured to detach the distal section 206 from the lumen 202 when sufficient tension is applied. In other embodiments, the lumen 202 may be continuous and not include a detachable distal section 206.
The length of the elongated member 202 is preferably long enough to pass entirely through and beyond the outer member's lumen. The length of the elongated member 202 may extend up to 40 cm beyond the outer catheter's lumen. For example, the elongated member 202 may have a length that allows extension of up to about 40, 35, 32, 18, 15, 10, 8, 5, or 2 cm beyond the outer member's distal end. The detachable distal section 206 similarly may vary in length. The detachable distal section 206 may be the last 2 cm of the elongated member 202. Other embodiments may include a detachable distal section 206 that is about 1.8, 1.5, 1.3, 1, 0.7, or 0.5 cm in length (or a length within a range with endpoints defined by any two of the foregoing values), for example.
In another embodiment, the stylette 300 may omit a microfabricated distal section 306. In some embodiments, disposed at or near the distal end of the stylette 300 is a radiopaque marker 308 configured to align near or at the distal end of the inner member 200 to assist in visualization of the distal end of the inner member 200. Another embodiment omits the radiopaque marker 308. In some embodiments, the stylette 300 may include a hydrophilic coating to allow the stylette 300 to be inserted into and move through the inner member 200 more easily.
In some embodiments, multiple inner members 200 may be used with a single outer member 100. For example, a first inner member may be used to deliver an embolic agent to a targeted treatment site. The first inner member may then be removed from the system, and a second inner member may then be routed through the outer member 100, past the distal end of the inner member 100, and toward the treatment site. The second inner member may be utilized to deliver a different agent, for example. Additionally, or alternatively, the outer member 100 may be moved to a different targeted treatment site in between use of the first and second inner members.
In some cases, the inner member may require more structural rigidity to move towards the treatment site. In these cases, the stylette 300 may be used. The stylette 300 provides greater stiffness to the inner member 200 to aid in guiding the inner member 200 closer to the treatment site. In other embodiments, the inner member 200 may be capable of reaching the targeted anatomy without the aid of the stylette 300. In these cases, the stylette 300 need not be inserted into the inner member 200. The inner member 200 may include a stopping element at the distal section configured to prevent the stylette's distal section from pushing distally past the inner member 200. The stopping element may be, for example, a notch, friction fit, or other appropriate means to stop the stylette's distal end from pushing past the inner member's distal end.
While certain embodiments of the present disclosure have been described in detail, with reference to specific configurations, parameters, components, elements, etcetera, the descriptions are illustrative and are not to be construed as limiting the scope of the claimed invention.
Furthermore, it should be understood that for any given element of component of a described embodiment, any of the possible alternatives listed for that element or component may generally be used individually or in combination with one another, unless implicitly or explicitly stated otherwise.
In addition, unless otherwise indicated, numbers expressing quantities, constituents, distances, or other measurements used in the specification and claims are to be understood as optionally being modified by the term “about” or its synonyms. When the terms “about,” “approximately,” “substantially,” or the like are used in conjunction with a stated amount, value, or condition, it may be taken to mean an amount, value or condition that deviates by less than 20%, less than 10%, less than 5%, less than 1%, less than 0.1%, or less than 0.01% of the stated amount, value, or condition. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Any headings and subheadings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims.
It will also be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” do not exclude plural referents unless the context clearly dictates otherwise. Thus, for example, an embodiment referencing a singular referent (e.g., “widget”) may also include two or more such referents.
It will also be appreciated that embodiments described herein may also include properties and/or features (e.g., ingredients, components, members, elements, parts, and/or portions) described in one or more separate embodiments and are not necessarily limited strictly to the features expressly described for that particular embodiment. Accordingly, the various features of a given embodiment can be combined with and/or incorporated into other embodiments of the present disclosure. Thus, disclosure of certain features relative to a specific embodiment of the present disclosure should not be construed as limiting application or inclusion of said features to the specific embodiment. Rather, it will be appreciated that other embodiments can also include such features.
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63/359,690, filed Jul. 8, 2022, and titled “Extendable Lumen Catheter Device,” which is incorporated herein in its entirety by this reference.
| Number | Date | Country | |
|---|---|---|---|
| 63359690 | Jul 2022 | US |
