US20170072165A1 - Catheter shaft and associated devices, systems, and methods - Google Patents

Abstract

Systems, devices, and methods for detaching an implantable device from a delivery system are disclosed herein. One aspect of the present technology, for example, is directed toward an elongated shaft having an inner surface that defines a lumen that extends distally from the proximal portion to an opening at a distal terminus of a distal portion. In some embodiments the distal portion includes an inner polymer structure having a first portion and a second portion positioned distal of the first portion along the length of the inner polymer structure. The first portion can have a first stiffness and the second portion can have a second stiffness less than the first stiffness. The distal portion can further include an outer polymer structure disposed around the inner polymer structure and a coil wound around the inner polymer structure and disposed within the outer polymer structure.

Description

TECHNICAL FIELD
• The present technology relates generally to catheters. More specifically, the invention relates to catheter shaft construction.
BACKGROUND
• A wide variety of medical devices have been developed for intravascular use. Catheters, for example, are commonly used to facilitate navigation through and/or treatment within the anatomy of a patient. To direct the distal portion of the catheter to the correct location in the vasculature, a physician must apply longitudinal forces, and sometimes rotational forces (i.e., torsional forces), from the proximal end of the catheter. For the catheter shaft to transmit these forces from the proximal end to the distal end, the catheter must be sufficiently rigid to be pushed through the blood vessel (a property commonly referred to as “pushability”), yet flexible enough to navigate through the often tortuous bends in the blood vessel. The catheter may also require sufficient torsional stiffness to transmit the applied torque (a property commonly referred to as “torqueability”). A need exists for catheter shafts that accomplish a balance between longitudinal rigidity, torsional stiffness, and flexibility.
BRIEF DESCRIPTION OF THE DRAWINGS
• Many aspects of the present technology can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.
• FIG. 1A is a side view of a catheter in accordance with the present technology.
• FIG. 1B is a cross-sectional side view of a portion the catheter shaft shown inFIG. 1A.
• FIG. 2 is a cross-sectional side view of a portion of an elongated catheter shaft configured in accordance with another embodiment of the present technology.
• FIG. 3 is a cross-sectional side view of a distal portion of an elongated catheter shaft configured in accordance with the present technology.
• FIG. 4 is a cross-sectional side view of a distal portion of an elongated catheter shaft configured in accordance with the present technology.
• FIG. 5 is a cross-sectional side view of a distal portion of an elongated catheter shaft configured in accordance with the present technology.
• FIG. 6 is a cross-sectional side view of a distal portion of an elongated shaft configured in accordance with the present technology.
• FIG. 7 is a cross-sectional side view of a distal portion of an elongated shaft configured in accordance with the present technology.
• FIG. 8 is a cross-sectional side view of a distal portion of an elongated shaft configured in accordance with the present technology.
DETAILED DESCRIPTION
• The present technology is directed to catheters and associated methods of manufacture. Specific details of several embodiments of catheter devices, systems, and methods in accordance with the present technology are described below with reference toFIGS. 1A-8. With regard to the terms “distal” and “proximal” within this description, unless otherwise specified, the terms can reference a relative position of the portions of a catheter and/or an associated device with reference to an operator and/or a location in the vasculature. Also, the term “thickness” as used herein with respect to a particular material or layer refers to the perpendicular distance between the plane running through and generally parallel with the radially outermost surface of the particular material or layer and the plane running through and generally parallel with the radially innermost surface of the particular material or layer.
I. SELECTED EMBODIMENTS OF CATHETER SHAFTS OF THE PRESENT TECHNOLOGY
• FIG. 1A is a side view of acatheter100 configured in accordance with an embodiment of the present technology, andFIG. 1B is a cross-sectional side view of a portion of thecatheter100 shown inFIG. 1A. Referring toFIGS. 1A-1B together, thecatheter100 includes ahandle assembly101 and anelongated shaft106 having aproximal portion106acoupled to thehandle assembly101 and adistal portion106b. Thehandle assembly101 includes ahub102 configured to facilitate connection to other devices (e.g., a syringe, a Y-adapter, etc.) and atransition portion104 configured to provide strain relief at theproximal portion106a. In other embodiments, thehandle assembly101 can have other suitable configurations based on the desired functions and characteristics of thecatheter100.
• Theshaft106 is a generally tubular member having an inner surface that defines a lumen103 (FIG. 1B) extending from theproximal portion106aof theshaft106 to anopening118 at the distal terminus of thedistal portion106b. In some embodiments, theshaft106 can include a radiopaque marker117 (FIG. 1B) surrounding thelumen103 at or just proximal to the opening118. Thelumen103 is configured to slidably receive and facilitate the passage therethrough of one or more medical devices, such as guidewires, balloon catheters, implants, intrasaccular occlusion devices (e.g., coils, expandable cages, expandable meshes, etc.), infusion devices, stents and/or stent-grafts, intravascular occlusion devices, clot retrievers, implantable heart valves, and other suitable medical devices and/or associated delivery systems. Additionally, thelumen103 is configured to receive one or more fluids therethrough, such as radiopaque dye, saline, drugs, and the like.
• The size of thelumen103 can vary, depending on the desired characteristics of thecatheter100. For example, in some embodiments theshaft106 can have an inner diameter (e.g., lumen diameter) between about 0.01 inches and about 0.05 inches (e.g., 0.017 inches, 0.0445 inches, etc.), and in some embodiments between about 0.02 inches and about 0.045 inches (e.g., 0.021 inches, etc.). In a particular embodiment, the inner diameter is between about 0.025 inches and about 0.04 inches (e.g., 0.027 inches, 0.032 inches, etc.). Although theshaft106 shown inFIG. 1A has a generally round cross-sectional shape, it will be appreciated that theshaft106 can include other cross-sectional shapes or combinations of shapes. For example, the cross-sectional shape of theshaft106 can be oval, rectangular, square, triangular, polygonal, and/or any other suitable shape and/or combination of shapes.
• The outer diameter of theshaft106 can be the same or vary along its length. For example, in the embodiment shown inFIGS. 1A-1B, theshaft106 has afirst portion190 with a first diameter, atapered portion192 with a diameter that decreases in a proximal to distal direction, and asecond portion194 with a second diameter less than the first diameter. The length of thetapered portion192 can be between about 1 cm and about 5 cm. In some embodiments, theshaft106 does not include asecond portion194 and thetapered portion192 extends distally to the distal terminus of theshaft106. In other embodiments, theshaft106 has an outer diameter that is generally constant along its length. Moreover, the length and/or outside diameter of theshaft106 is generally selected for the desired use of thecatheter100. For example, in those embodiments where thecatheter100 is configured as a guide catheter for enabling intravascular insertion and navigation, the outside diameter of theshaft106 can be between about 3 Fr and about 10 Fr. In those embodiments where thecatheter100 is configured as a microcatheter for use within small anatomies of the patient, the outside diameter of theshaft106 can be between about 1 Fr and about 3 Fr.
• Many embodiments of the present technology are particularly useful in treating targets located in tortuous and narrow vessels, such as certain sites in the neurovascular system, the coronary vascular system, or the peripheral vascular system (e.g., the superficial femoral, popliteal, or renal arteries). Neurovascular target sites, such as sites in the brain, are often accessible only via a tortuous vascular path. Although some embodiments of thecatheter100 are described in terms of intravascular use, in other embodiments thecatheter100 may be suited for uses in the digestive system, soft tissues, and/or any other insertion into an organism for medical uses. For example, in some embodiments, thecatheter100 may be significantly shorter and used as an introducer sheath, while in other embodiments thecatheter100 may be adapted for other medical procedures.
• In the embodiment shown inFIG. 1B, theelongated shaft106 includes aninner polymer structure114 and anouter polymer structure116 surrounding at least a portion of theinner polymer structure114. Theshaft106 shown inFIG. 1B also has aninner braid160 embedded in theouter polymer structure116, anouter braid162 surrounding at least a portion of theinner braid160, and acoil170 wrapped around at least a portion of theinner polymer structure114. Each of these subcomponents will now be described in greater detail.
• Referring again toFIGS. 1A-1B together, theinner polymer structure114 extends from theproximal portion106aof theshaft106 to a location within thedistal portion106bof theshaft106. For example, in the embodiment shown inFIG. 1B, theinner polymer structure114 extends from theproximal portion106aof theshaft106 to theopening118 at the distal terminus of thedistal portion106b(e.g., the entire length of theshaft106 or substantially the entire length of the shaft106). In other embodiments, theinner polymer structure114 extends along only a portion of the length of theshaft106 and/or has a proximal and/or a distal terminus that does not correspond to a proximal terminus and/or a distal terminus, respectively, of theshaft106. The length of theinner polymer structure114 can vary depending upon, for example, the length of theshaft106 and the desired characteristics and functions of thecatheter100.
• Theinner polymer structure114 can be made of any suitable polymer (and/or combination of multiples polymers) and by any suitable process. Suitable polymers can include, for example, polyoxymethylene (POM), polybutylene terephthalate (PBT), polyether block ester, polyether block amide (PEBA), fluorinated ethylene propylene (FEP), polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyurethane, polytetrafluoroethylene (PTFE), polyether-ether ketone (PEEK), polyimide, polyamide, polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polysulfone, nylon, perfluoro(propyl vinyl ether) (PFA), polyether-ester, platinum, polymer/metal composites, etc., or mixtures, blends or combinations thereof, and may also include or be made up of a lubricious polymer having a low coefficient of friction. In some embodiments (not shown), theinner polymer structure114 includes one or more metals or metal alloys and/or combinations thereof. In a particular embodiment, theinner polymer structure114 does not include any polymer material and solely comprises a metal and/or metal alloy.
• Theinner polymer structure114 can include a single layer of material or it can have two or more layers of the same or different materials. For example, in the embodiment shown inFIG. 1B, theinner polymer structure114 includes afirst layer112 and asecond layer113 surrounding at least a portion of thefirst layer112. An inner surface of thefirst layer112 defines theshaft lumen103. Thefirst layer112 can comprise a lubricious polymer such as HDPE or PTFE, for example, or platinum, PEEK, PE, PP, or a copolymer of tetrafluoroethylene, such as FEP, a copolymer of tetrafluoroethylene with perfluoroethers, such as perfluoroalkoxy alkanes (PFA) (more specifically, perfluoropropyl vinyl ether or perfluoromethyl vinyl ether), or the like. Thesecond layer113 can be made of any of the materials described above with respect to theinner polymer structure114 such as, for example, PEBA, PVC, PE, etc. In other embodiments, theinner polymer structure114 can be formed of a single layer (e.g., only thefirst layer112, only thesecond layer113, etc.), and in other embodiments theinner polymer structure114 can include more than two layers (e.g., three layers, four layers, etc.) depending upon the desired characteristics of thecatheter100. In some embodiments the first andsecond layers112,113 have generally the same lengths and are coextensive along the length of theshaft106, and in other embodiments the first andsecond layers112,113 have different lengths and/or are not coextensive along theshaft106. For example, in a particular embodiment, thesecond layer113 extends along only a portion of the length of theshaft106 while thefirst layer112 extends the entire length (or substantially the entire length) of theshaft106. In any of the above embodiments, thefirst layer112 can have a thickness of about 0.0005 inches to about 0.005 inches, or about 0.001 inches to about 0.003 inches. Also, in any of the above embodiments, thesecond layer113 can have a thickness of about 0.0005 inches to about 0.005 inches, or about 0.001 inches to about 0.003 inches.
• The stiffness of theinner polymer structure114 can be generally uniform along its length, or the stiffness can vary along its length. The stiffness variation is a function of the size, shape, thickness, and/or materials of theinner polymer structure114. In embodiments where the stiffness of theinner polymer structure114 varies along its length, the stiffness can change continuously (e.g., gradually) and/or be stepped from one section to another. In some embodiments, the stiffness of theinner polymer structure114 decreases in a proximal to distal direction along its length. In other embodiments, the stiffness of theinner polymer structure114 increases in a proximal to distal direction along it length, and/or increases and decreases in a proximal to distal direction along its length. Additionally, theinner polymer structure114 can be made of or include a radiopaque material for radiographic visualization. Exemplary radiopaque materials include, for example, gold, platinum, palladium, tantalum, tungsten alloy, polymer materials loaded with radiopaque fillers, and the like. Likewise, in some embodiments, theinner polymer structure114 is made of or include a material that may aid in MRI imaging, such as, for example, tungsten, Elgiloy, MP35N, nitinol, and others.
• In the embodiment shown inFIGS. 1A-1B, theouter polymer structure116 directly contacts at least a portion of theinner polymer structure114 and encases at least a portion of each of theinner braid160, theouter braid162, and thecoil170. Theouter polymer structure116 extends distally from theproximal portion106aof theshaft106 to a location within thedistal portion106bof the shaft106 (e.g., the entire length of theshaft106 or substantially the entire length of the shaft106). The length of theouter polymer structure116 can vary depending upon, for example, the length of theshaft106 and the desired characteristics and functions of thecatheter100. In some embodiments, theouter polymer structure116 extends substantially the entire length of theshaft106. In other embodiments, theouter polymer structure116 extends along only a portion of the length of theshaft106 and/or has a proximal and/or distal terminus that does not correspond to a proximal terminus and/or distal terminus, respectively, of theshaft106.
• The outer polymer structure116 (and/or portions thereof) can be made of any suitable polymer (or composites or combinations thereof) and by any suitable process. Suitable polymers can include, for example, polyoxymethylene (POM), polybutylene terephthalate (PBT), polyether block ester, polyether block amide (PEBA), fluorinated ethylene propylene (FEP), polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyurethane, polytetrafluoroethylene (PTFE), polyether-ether ketone (PEEK), polyimide, polyamide, polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polysulfone, nylon, perfluoro(propyl vinyl ether) (PFA), polyether-ester, platinum, polymer/metal composites, etc., or mixtures, blends or combinations thereof. In several embodiments, theouter polymer structure116 is or at least includes a lubricious polymer. In some embodiments (not shown), theouter polymer structure116 includes one or more metals or metal alloys (combinations thereof). In a particular embodiment, theouter polymer structure116 does not include any polymer material and solely comprises a metal and/or metal alloy.
• In some embodiments, the stiffness of theouter polymer structure116 varies along its length. In such embodiments, the stiffness variation may be continuous or stepped by varying the size, shape, thickness, and/or material composition of theouter polymer structure116. For example, in the embodiment shown inFIGS. 1A-1B, theouter polymer structure116 includes four unique portions along its length (labeled proximal to distal as first, second, third andfourth portions120,130,140, and150, respectively) in which the respective stiffnesses of theportions120,130,140,150 decrease sequentially in a proximal to distal direction. For example, thefirst portion120 has a first stiffness, thesecond portion130 has a second stiffness less than the first stiffness, thethird portion140 has a third stiffness less than the second stiffness, and thefourth portion150 has a fourth stiffness less than the third stiffness. In other embodiments, the stiffness of theouter polymer structure116 and/or the stiffnesses of theindividual portions120,130,140,150 can increase in a proximal to distal direction (e.g., thesecond portion130 can be stiffer than thefirst portion120, etc.), increase and decrease in a proximal to distal direction (e.g., thesecond portion130 can be stiffer than thefirst portion120 but less stiff than thethird portion140, etc.), or be generally uniform in a proximal to distal direction. In other embodiments, theouter polymer structure116 can have more or fewer portions (e.g., one continuous portion, two portions, three portions, five portions, etc.).
• In some embodiments, one or both of the first andsecond portions120,130 can have an individual thickness of about 0.003 inches to about 0.005 inches, and in some embodiments, about 0.004 inches to about 0.010 inches. Thefourth portion150 can have a thickness of about 0.001 inches to about 0.003 inches. The proximal portion of the taperedportion192 can have a thickness equivalent to that of the correspondingsecond portion130, and the distal portion of the taperedportion192 can have a thickness generally equivalent to that of the correspondingfourth portion150. Thus, thethird portion140 can have a proximal thickness between about 0.003 inches to about 0.005 inches, or in some embodiments about 0.004 inches to about 0.010 inches, and a distal portion have a thickness of about 0.001 inches to about 0.003 inches.
• Theportions120,130,140,150, either individually or any combination thereof, can be made of the same or different materials, have the same or different size, have the same or different thickness, and/or have the same or different cross-sectional shape. In some embodiments, theouter polymer structure116 can include two or more layers (e.g., an inner layer surrounding an outer layer, etc.), and each layer can have the same or different material compositions, thicknesses, and/or stiffnesses. Additionally, theportions120,130,140,150, either individually or any combination thereof, can have a uniform or varying stiffness along its respective length. In other words, theportions120,130,140,150, either individually or any combination thereof, can have a uniform or varying size, shape, thickness, and/or material composition along its respective length. For example, in the embodiment shown inFIG. 1B, each of theportions120,130,140,150 has a constant material composition and cross-sectional shape along its respective length. Each of the first, second, andfourth portions120,130,150 also has a generally constant thickness along its respective length; accordingly, each of the first, second, andfourth portions120,130,150 has a generally constant stiffness along its respective length. Thethird portion140, however, includes the tapered portion192 (FIG. 1A) and thus varies in thickness (and stiffness) along its length. In other embodiments, thethird portion140 does not coincide with the taperedportion192 and/or the taperedportion192 spans more than one of theportions120,130,140,150.
• It will be appreciated that while theinner polymer structure114 and theouter polymer structure116 are described herein as separate components with respect to the illustrated embodiments, the inner andouter polymer structures114,116 can be provided as a single layer or structure. For example, theinner polymer structure114 andouter polymer structure116 may be provided separately, but attached or combined together to physically form a single layer (e.g., a single homogeneous material).
• Referring still to the embodiment shown inFIG. 1B, theinner braid160 is on and around theinner polymer structure114, and theouter polymer structure116 is on and around theinner braid160. In some embodiments, theinner braid160 directly contacts at least a portion of both theinner polymer structure114 and theouter polymer structure116. In other embodiments, theouter polymer structure116 is between at least a portion of theinner polymer structure114 and at least a portion of theinner braid160. In the embodiment shown inFIGS. 1A-1B, theinner braid160 extends distally from theproximal portion106aof theshaft106 to adistal terminus160baligned with or just proximal of the distal terminus of theshaft106. In other embodiments, theinner braid160 extends the entire length of theshaft106. The length of theinner braid160 can vary depending upon, for example, the length of theshaft106 and the desired characteristics and functions of thecatheter100.
• In some embodiments, at least a portion of theinner braid160 is coextensive with at least a portion of theouter braid162. For example, in the embodiment shown inFIG. 1B, theinner braid160 has adistal terminus160blocated at a position along theshaft106 distal of a proximal terminus (not shown) of theouter braid162 and proximal of adistal terminus162bof theouter braid162. In other embodiments (not shown), no portion of theinner braid160 is coextensive with a portion of theouter braid162. Additionally, in some embodiments at least a portion of theinner braid160 is coextensive with at least a portion of thecoil170, and in other embodiments theinner braid160 is adjacent to and/or spaced apart from thecoil170 along the length of theshaft106. For example, in the embodiment shown inFIG. 1B, thedistal terminus160bof theinner braid160 is located at a position along theshaft106 proximal of aproximal terminus170aof thecoil170 such that no portion of theinner braid160 is coextensive with any portion of thecoil170. Alternatively, in some embodiments (not shown) thedistal terminus160bof theinner braid160 is located at a position along theshaft106 distal of aproximal terminus170aof thecoil170 such that at least a portion of theinner braid160 is coextensive with at least a portion of thecoil170.
• In the embodiment shown inFIGS. 1A-1B, theouter braid162 is around theinner braid160, and theouter polymer structure116 contacts theouter braid162. In some embodiments theouter braid162 directly contacts theinner braid160. In other embodiments, theouter polymer structure116 is between at least a portion of theinner braid160 and at least a portion of theouter braid162. In the embodiment shown inFIG. 1B, a distal portion of theouter braid162 is around a proximal portion of thecoil170. In some embodiments theouter braid162 directly contacts thecoil170. In other embodiments, theouter polymer structure116 is between at least a portion of theouter braid162 and at least a portion of thecoil170.
• Theouter braid162 extends distally from theproximal portion106aof theshaft106 to adistal terminus162bproximal to the distal terminus of theshaft106. In other embodiments, theouter braid162 extends the entire length of theshaft106. The length of theouter braid162 can vary depending upon, for example, the length of theshaft106 and the desired characteristics and functions of thecatheter100. In some embodiments, at least a portion of theouter braid162 is coextensive with at least a portion of thecoil170. For example, in the embodiment shown inFIG. 1B, thedistal terminus162bof theouter braid162 is located at a position along theshaft106 that is distal of theproximal terminus170aof thecoil170. In those embodiments where at least a portion of theouter braid162 is coextensive with at least a portion of thecoil170, the coextensive portions of theouter braid162 and thecoil170 form anoverlapping region180. As shown inFIG. 1B, in some embodiments theouter braid162 surrounds thecoil170 within the overlappingregion180. In other embodiments, thecoil170 surrounds theouter braid162 within the overlapping region180 (FIG. 2, described in greater detail below). In yet other embodiments, theouter braid162 is spaced apart from and/or adjacent to thecoil170 such that no portion of theouter braid162 is coextensive with any portion of thecoil170.
• Theinner braid160 and/or theouter braid162 can individually have a generally uniform pitch along its respective length or may have a varying pitch along its respective length. The flexibility of the individualinner braid160 and/or theouter braid162 may vary continuously along its respective length by continuously varying the pitch or may vary along its respective length in a stepwise fashion by stepwise varying the pitch. Moreover, theinner braid160 and/or theouter braid162 can individually have a generally constant braid angle along its respective length or have a varying braid angle along its respective length to provide different zones of stiffness and/or flexibility. Theinner braid160 and/or theouter braid162 can be formed of braided filaments having the same or varying diameters (individually and/or relative to the other braid). In some embodiments, theinner braid160 and/or theouter braid162 are further shaped using a heat setting process. Additionally, theinner braid160 and theouter braid162 can have the same or different pitch, stiffness, braid angle, filament diameters, and filament count. In some embodiments, the inner and/orouter braids160,162 individually have a pitch of 45 PPI to 80 PPI. In a particular embodiment, theshaft106 includes a single braid. Additionally, in some embodiments, theinner braid160 and/or theouter braid162 can be made of or include a radiopaque or imaging material.
• The inner160 and/orouter braids162 are formed of a plurality of interwoven wires. The wires can have a circular or rectangular cross-sectional shape. The wires can be made of one or more metals, such as stainless steel, platinum, silver, tantalum, and the like. In some embodiments, the wires can include or be made of non-metallic materials. In some embodiments, the wires are made of a superelastic or shape-memory material, such as nitinol. For those embodiments utilizing wires having a rectangular shape, the wires can have a cross-sectional area of about 0.0005 inches by 0.0025 inches to about 0.001 inches by 0.005 inches.
• Thecoil170 can be one or more round wires or flat ribbons helically wound around theinner polymer structure114. In the embodiment shown inFIGS. 1A-1B, theouter polymer structure116 encases thecoil170. Theproximal terminus170aof thecoil170 is positioned along thedistal portion106bof theshaft106, and thedistal terminus170bof thecoil170 is positioned generally in alignment with or just proximal to the distal terminus of theshaft106. Accordingly, thecoil170 is completely disposed within the distal portion of the shaft. In other embodiments, at least a portion of thecoil170 is outside of thedistal portion106bof theshaft106. The pitch of adjacent turns of thecoil170 may be tightly wound so that each turn touches the succeeding turn or the pitch may be set such that thecoil170 is wound in an open fashion. The pitch of thecoil170 can be the same or may vary along the length of thecoil170. Thecoil170 can have a pitch of about 0.004 inches to about 0.014 inches. In some embodiments, the pitch of thecoil170 depends on the inner diameter of theshaft106. For example, for a shaft inner diameter of about 0.017 inches, thecoil170 can have a pitch of about 0.004 inches to about 0.009 inches. For a shaft inner diameter of about 0.021 inches, thecoil170 can have a pitch of about 0.006 inches to about 0.011 inches. For a shaft inner diameter of about 0.027 inches, thecoil170 can have a pitch of about 0.007 inches to about 0.012 inches. For a shaft inner diameter of about 0.0045 inches, thecoil170 can have a pitch of about 0.010 inches to about 0.014 inches. Additionally, in some embodiments, thecoil170 or portions thereof can be made of or include a radiopaque or imaging material.
• The wire of thecoil170 can be made of one or more metals, such as stainless steel, platinum, silver, tantalum, and the like. In other embodiments, the wire of thecoil170 can include or be made of non-metallic materials. In a particular embodiment, the wires are made of a superelastic or shape-memory material, such as nitinol The wire can have an outer diameter of about 0.001 inches to about 0.005 inches, or in some embodiments about 0.001 inches to about 0.003 inches.
• It will be appreciated that theinner braid160,outer braid162, andcoil170 can have other suitable configurations and/or relative positions along the length of theshaft106. For example, in some embodiments theinner braid160 can be coextensive with at least a portion of thecoil170, and in some embodiments theinner braid160 can be generally coextensive with theouter braid162. In a particular embodiment, at least a portion of theouter braid162 is not coextensive with a portion of thecoil170.
• FIG. 2 is a cross-sectional side view of a portion of acatheter shaft206 configured in accordance with another embodiment of the present technology. Theshaft206 can be generally similar to theshaft106 shown inFIGS. 1A-1B, except thecoil170 in theshaft206 ofFIG. 2 surrounds theouter braid162 within the overlappingregion180.
II. SELECTED EMBODIMENTS OF DISTAL PORTIONS OF CATHETER SHAFTS OF THE PRESENT TECHNOLOGY
• FIGS. 3-8 are cross-sectional side views of distal portions of catheter shafts configured in accordance with the present technology. Any of the distal portions (or aspects thereof) described below can be combined with any of the catheter shafts described above with reference toFIGS. 1A-2. As described in greater detail below, the distal portion embodiments of the present technology include regions of varying stiffness and/or preferential bending that provide improved bending/buckling at the distal portion when contacting the wall of tortuous vessels, thereby improving ease of navigation of the corresponding shaft and/or distal portion.
• FIG. 3 is a cross-sectional side view of adistal portion300 of a catheter shaft configured in accordance with the present technology. Thedistal portion300 can include aradiopaque marker317, aninner polymer structure314, anouter polymer structure316 surrounding at least a portion of theinner polymer structure314, and acoil370 wrapped around at least a portion of theinner polymer structure314. As shown inFIG. 3, theinner polymer structure314 extends the length of thedistal portion300 such that theinner polymer structure314 terminates distally at anopening318 at the distal terminus of thedistal portion300. Theinner polymer structure314 defines a lumen that can be generally continuous with thelumen103 of any of the shaft embodiments described above with reference toFIGS. 1A-2.
• Theinner polymer structure314 can include a single layer of material or it can have two or more layers of the same or different materials. For example, in the embodiment shown inFIG. 3, theinner polymer structure314 includes afirst layer312 and asecond layer313 surrounding thefirst layer312. Accordingly, an inner surface of thefirst layer312 defines theshaft lumen103 at thedistal portion300. Thefirst layer312 can comprise a lubricious polymer such as HDPE or PTFE, for example, or platinum, PEEK, PE, PP, or a copolymer of tetrafluoroethylene, such as FEP, a copolymer of tetrafluoroethylene with perfluoroethers, such as PFA (more specifically, perfluoropropyl vinyl ether or perfluoromethyl vinyl ether), or the like. Thesecond layer313 can be made of any of the materials described above with respect to theinner polymer structure114. Moreover, in some embodiments theinner polymer structure314 can be formed of a single layer (e.g., only thefirst layer312, only thesecond layer313, etc.), and in other embodiments theinner polymer structure314 can include more than two layers (e.g., three layers, four layers) depending on the desired characteristics of thedistal portion300 of the catheter.
• The stiffness of theinner polymer structure314 can be generally uniform along its length, or the stiffness can vary along its length. In the embodiment shown inFIG. 3, thesecond layer313 of theinner polymer structure314 includes two unique portions along its length (labeled proximal to distal asfirst portion319 and second portion320). The first andsecond portions319,320 can have at least one of a different size, shape, thickness, and material composition such that thefirst portion319 has a different stiffness than the second portion320 (or in other words, thesecond portion320 is softer than the first portion319). For example, thefirst portion319 can be a first material and thesecond portion320 can be a second material different than the first material such that a stiffness of thefirst portion319 is greater than a stiffness of thesecond portion320. In other embodiments, a stiffness of theinner polymer structure314 can increase in a proximal to distal direction along its length, or increase and decrease in a proximal to distal direction along its length. For example, in a particular embodiment, thesecond portion320 can have a stiffness that is greater than or equal to the stiffness of thefirst portion319. In other embodiments, theinner polymer structure314 can have more or fewer portions (e.g., one continuous portion, three portions, four portions, etc.).
• In the embodiment shown inFIG. 3, both the first andsecond layers312,313 of theinner polymer structure314 extend along the entire length of thedistal portion300 such that the distal termini of both the first andsecond layers312,313 are at the distal terminus of thedistal portion300. Additionally, thesecond portion319 of thesecond layer313 defines a portion of the distal terminus of thedistal portion300 of the shaft. As such, the distal-most surfaces of both the inner and theouter polymer structures314,316 define the distal terminus of thedistal portion300 of the shaft. In other embodiments, thefirst layer312 terminates proximal to the distal terminus of thedistal portion300.
• Although theinner polymer structure314 is shown having twoportions319,320 inFIG. 3, in other embodiments theinner polymer structure314 can have a single continuous portion or more than two portions (e.g., three portions, four portions, etc.). Moreover, although thesecond layer313 is shown having multiple portions, in other embodiments thefirst layer312 can additionally or alternatively include multiple portions.
• Referring still to the embodiment shown inFIG. 3, theouter polymer structure316 directly contacts at least a portion of theinner polymer structure314 and encases at least a portion of thecoil370. For example, in the embodiment shown inFIG. 3, at least a portion of the surface of thecoil370 directly contacts the first andsecond portions319,320 of thesecond layer313 of theinner polymer structure314, while a remaining portion of the coil's surface directly contacts theouter polymer structure316. Additionally, theouter polymer structure316 extends along the length of thedistal portion300 such that a distal terminus of theouter polymer structure316 corresponds to the distal terminus of thedistal portion300. In other embodiments, theouter polymer structure316 extends along only a portion of the length of thedistal portion300 and/or has a proximal and/or distal terminus that does not correspond to a proximal terminus and/or distal terminus, respectively, of thedistal portion300. Moreover, the outer polymer structure316 (and/or portions thereof) can be made of any of the materials described above with respect to theouter polymer structure116.
• Thecoil370 can be one or more round wires or flat ribbons helically wound around theinner polymer structure314, and theouter polymer structure316 can encase at least a portion of thecoil370. Thecoil370 can extend all or a portion of the length of thedistal portion300. For example, in the embodiment shown inFIG. 3, thecoil370 has a distal terminus that is aligned with or just proximal of theradiopaque marker317, and theradiopaque marker317 is proximal of the distal terminus of thedistal portion300. As such, a distal terminus of thecoil370 is spaced apart from a distal terminus of the shaft. The pitch of adjacent turns of thecoil370 may be tightly wound so that each turn touches the succeeding turn or the pitch may be set such that thecoil370 is wound in an open fashion. The pitch of thecoil370 can be the same or vary along the length of thecoil370. Additionally, in some embodiments, thecoil370 or portions thereof can be made of or include a radiopaque or imaging material.
• FIG. 4 is a cross-sectional side view of adistal portion400 of a catheter shaft configured in accordance with another embodiment of the present technology. Thedistal portion400 can include aradiopaque marker417, aninner polymer structure414, anouter polymer structure416 surrounding at least a portion of theinner polymer structure414, and acoil470 wound around at least a portion of theinner polymer structure414. Theinner polymer structure414 defines a lumen that can be generally continuous with thelumen103 of any of the shaft embodiments described above with reference toFIGS. 1A-2.
• Theinner polymer structure414 can include a single layer of material or it can have two or more layers of the same or different materials. For example, in the embodiment inFIG. 4, theinner polymer structure414 includes afirst layer412 and asecond layer413 surrounding thefirst layer412. Accordingly, an inner surface of thefirst layer412 defines theshaft lumen103 at thedistal portion400. Thefirst layer412 can comprise a lubricious polymer such as HDPE or PTFE, for example, or platinum, PEEK, PE, PP, or a copolymer of tetrafluoroethylene, such as FEP, a copolymer of tetrafluoroethylene with perfluoroethers, such as PFA (more specifically, perfluoropropyl vinyl ether or perfluoromethyl vinyl ether), or the like. Thesecond layer413 can be made of any of the materials described above with respect to theinner polymer structure414. Moreover, in some embodiments theinner polymer structure414 can be formed of a single layer (e.g., only thefirst layer412, only thesecond layer413, etc.), and in other embodiments theinner polymer structure414 can include more than two layers (e.g., three layers, four layers) depending upon the desired characteristics of the catheter.
• The stiffness of theinner polymer structure414 can be generally uniform along its length, or the stiffness can vary along its length. In the embodiment shown inFIG. 4, thesecond layer413 of theinner polymer structure414 includes two unique portions (labeled proximal to distal asfirst portion419 and second portion420) adjacent one another along its length having different stiffnesses. The first andsecond portions419,420 can have at least one of a different size, shape, thickness, and material composition such that thefirst portion419 has a different stiffness than thesecond portion420. For example, thefirst portion419 can be a first material and thesecond portion420 can be a second material different than the first material such that a stiffness of thefirst portion419 is greater than a stiffness of thesecond portion420. In other embodiments, a stiffness of theinner polymer structure414 can increase in a proximal to distal direction along its length, or increase and decrease in a proximal to distal direction along its length. For example, in a particular embodiment, thesecond portion420 has a stiffness that is greater than or equal to the stiffness of thefirst portion419.
• In the embodiment shown inFIG. 4, thesecond layer413 of theinner polymer structure414 extends along only a portion of the length of thedistal portion400 such that a distal terminus of thesecond layer413 is proximal of the distal terminus of theouter polymer structure416 and the distal terminus of thedistal portion400. Accordingly, in contrast to the embodiment shown inFIG. 3, only the distal-most portions of theouter polymer structure416 and thefirst layer312 define the distal terminus of thedistal portion400 of the shaft (and not the second layer313). Likewise, adistal region421 of thedistal portion400 does not include thesecond layer413 and comprises only thefirst layer412, theouter polymer structure416, theradiopaque marker417, and a portion of thecoil470. Accordingly, thedistal region421 is more flexible than the remainder of thedistal portion400. In some embodiments, thefirst layer412 and/or thecoil470 terminates proximal of thedistal region421 such that thedistal region412 comprises thefirst layer412 and theouter polymer structure416. The length of thedistal region421 can be between about 0.5 mm and about 5 cm.
• Although theinner polymer structure414 is shown having twoportions419,420 inFIG. 4, in other embodiments theinner polymer structure414 can have a single continuous portion or more than two portions (e.g., three portions, four portions, etc.). Moreover, although thesecond layer413 is shown having multiple portions, in other embodiments thefirst layer412 can additionally or alternatively include multiple portions.
• Referring still to the embodiment shown inFIG. 4, theouter polymer structure416 directly contacts at least a portion of theinner polymer structure414 and encases at least a portion of thecoil470. For example, in the embodiment shown inFIG. 4, at least a portion of the surface of thecoil470 directly contacts theinner polymer structure414, while a remaining portion of the coil's surface directly contacts theouter polymer structure416. As shown inFIG. 4, in some embodiments theouter polymer structure416 extends along the length of thedistal portion400 such that a distal terminus of theouter polymer structure416 corresponds to the distal terminus of thedistal portion400. The outer polymer structure416 (and/or portions thereof) can be made of any of the materials described above with respect to theouter polymer structure116.
• Thecoil470 can be one or more round wires or flat ribbons helically wound around theinner polymer structure414. Thecoil470 can extend all or a portion of the length of thedistal portion400. For example, in the embodiment shown inFIG. 4, thecoil470 has a distal terminus that is aligned with or just proximal of theradiopaque marker417, and theradiopaque marker417 is proximal of the distal terminus of thedistal portion400. The pitch of adjacent turns of thecoil470 may be tightly wound so that each turn touches the succeeding turn or the pitch may be set such that thecoil470 is wound in an open fashion. The pitch of thecoil470 can be the same or vary along the length of thecoil470. Additionally, in some embodiments, thecoil470 or portions thereof can be made of or include a radiopaque or imaging material.
• Thedistal portions300/400 provide several advantages over distal portions of conventional catheters, especially microcatheters for delivering occlusive devices (such as coils) to cerebral aneurysms. For example, thedistal portions300 and400 have a (relatively) softer distal tip and a (relatively) stiffer region immediately adjacent and proximal to the softer distal tip. Such a construction allows for improved bending and trackability at the distal tip bend (for positioning at the aneurysm neck) while the proximal stiffer region of thedistal portion300/400 provides additional support and stability to thedistal portion300/400, thereby lessening or preventing kickback of the shaft during deployment of an occlusive device (such as a coil) in an aneurysm.
• FIG. 5 is a cross-sectional side view of adistal portion500 of a catheter shaft configured in accordance with another embodiments of the present technology. Thedistal portion500 can include aradiopaque marker517, aninner polymer structure514, anouter polymer structure516 surrounding at least a portion of theinner polymer structure514, and acoil570 wound around at least a portion of theinner polymer structure514. In the embodiment shown inFIG. 5, theinner polymer structure514 extends the length of thedistal portion500 such that theinner polymer structure514 terminates distally at anopening518 at the distal terminus of thedistal portion500. Theinner polymer structure514 defines a lumen that can be generally continuous with thelumen103 of any of the shaft embodiments described above with reference toFIGS. 1A-2.
• Theinner polymer structure514 can include a single layer of material or it can have two or more layers of the same or different materials. For example, in the embodiment shown inFIG. 5, theinner polymer structure514 includes afirst layer512 and asecond layer513 surrounding thefirst layer512. As such, an inner surface of thefirst layer512 defines theshaft lumen103. Thesecond layer513 can be made of any of the materials described above with respect to theinner polymer structure514. Thefirst layer512 can comprise a lubricious polymer such as HDPE or PTFE, for example, or platinum, PEEK, PE, PP, or a copolymer of tetrafluoroethylene, such as FEP, a copolymer of tetrafluoroethylene with perfluoroethers, such as PFA (more specifically, perfluoropropyl vinyl ether or perfluoromethyl vinyl ether), or the like. Moreover, in some embodiments theinner polymer structure514 can be formed of a single layer (e.g., only thefirst layer512, only thesecond layer513, etc.), and in other embodiments theinner polymer structure514 can include more than two layers (e.g., three layers, four layers) depending upon the desired characteristics of the device.
• Theouter polymer structure516 directly contacts at least a portion of theinner polymer structure514 and encases at least a portion of thecoil570. For example, in the embodiment shown inFIG. 5, at least a portion of the surface of thecoil570 directly contacts thesecond layer513 of theinner polymer structure514, while a remaining portion of the coil's surface directly contacts theouter polymer structure516. As shown inFIG. 5, in some embodiments theouter polymer structure516 extends along the length of thedistal portion500 such that a distal terminus of theouter polymer structure516 corresponds to the distal terminus of thedistal portion500. The outer polymer structure516 (and/or portions thereof) can be made of any of the materials described above with respect to theouter polymer structure116.
• Thecoil570 can be one or more round wires or flat ribbons helically wound around theinner polymer structure514. Thecoil570 can extend all or a portion of the length of thedistal portion500. For example, in the embodiment shown inFIG. 5, thecoil570 has a distal terminus that is aligned with or just proximal of theradiopaque marker517, and theradiopaque marker517 is proximal of the distal terminus of thedistal portion500. The pitch of adjacent turns of thecoil570 may be tightly wound so that each turn touches the succeeding turn or the pitch may be set such that thecoil570 is wound in an open fashion. The pitch of thecoil570 can be the same or vary along the length of thecoil570. For example, in the embodiment shown inFIG. 5, thecoil570 has afirst portion572 and asecond portion574 distal of thefirst portion572. Thefirst portion572 has a first pitch and thesecond portion574 has a second pitch that is greater than the first pitch. Accordingly, a length of thedistal portion500 corresponding to thefirst portion572 of thecoil570 is less flexible than a length of thedistal portion500 corresponding to thesecond portion574 of thecoil570. Additionally, in some embodiments, thecoil570 or portions thereof can be made of or include a radiopaque or imaging material.
• FIG. 6 is a cross-sectional side view of adistal portion600 of a catheter shaft configured in accordance with the present technology. Thedistal portion600 can include aradiopaque marker617, aninner polymer structure614, anouter polymer structure616 surrounding at least a portion of theinner polymer structure614, and acoil670 wound around at least a portion of theinner polymer structure614. In the embodiment shown inFIG. 6, theinner polymer structure614 extends the length of thedistal portion600 such that theinner polymer structure614 terminates distally at an opening618 at the distal terminus of thedistal portion600. Theinner polymer structure614 defines a lumen that can be generally continuous with thelumen103 of any of the shaft embodiments described above with reference toFIGS. 1A-2.
• Theinner polymer structure614 can include a single layer of material or it can have two or more layers of the same or different materials. For example, as shown inFIG. 6, theinner polymer structure614 can include afirst layer612 and asecond layer613 surrounding thefirst layer612. As such, an inner surface of thefirst layer612 defines theshaft lumen103. Thesecond layer613 can be made of any of the materials described above with respect to theinner polymer structure614. Thefirst layer612 can include a lubricious polymer such as HDPE or PTFE, for example, or a copolymer of tetrafluoroethylene with perfluoroalkyl vinyl ether (PFA) (more specifically, perfluoropropyl vinyl ether or perfluoromethyl vinyl ether), or the like. Moreover, in some embodiments theinner polymer structure614 can be formed of a single layer (e.g., only thefirst layer612, only thesecond layer613, etc.), and in other embodiments theinner polymer structure614 can include more than two layers (e.g., three layers, four layers) depending upon the desired characteristics of the device.
• Theouter polymer structure616 directly contacts at least a portion of theinner polymer structure614 and encases at least a portion of thecoil670. For example, in the embodiment shown inFIG. 6, at least a portion of the surface of thecoil670 directly contacts thesecond layer613 of theinner polymer structure614, while a remaining portion of the coil's surface directly contacts theouter polymer structure616. In some embodiments theouter polymer structure616 extends along the length of thedistal portion600 such that a distal terminus of theouter polymer structure616 corresponds to the distal terminus of thedistal portion600. The outer polymer structure616 (and/or portions thereof) can be made of any of the materials described above with respect to theouter polymer structure116.
• Thecoil670 can be one or more round wires or flat ribbons helically wound around theinner polymer structure614. Thecoil670 can extend all or a portion of the length of thedistal portion600. For example, in the embodiment shown inFIG. 6, thecoil670 has a distal terminus that is aligned with or just proximal of theradiopaque marker617, and theradiopaque marker617 is proximal of the distal terminus of thedistal portion600. The pitch of adjacent turns of thecoil670 may be tightly wound so that each turn touches the succeeding turn or the pitch may be set such that thecoil670 is wound in an open fashion. The pitch of thecoil670 can be the same or vary along the length of thecoil670. For example, in the embodiment shown inFIG. 6, thecoil670 has afirst portion672, asecond portion674 distal of thefirst portion672, and athird portion676 distal of thesecond portion674. Thefirst portion672 has a first pitch, thesecond portion674 has a second pitch less than the first pitch, and thethird portion676 has a third pitch greater than the second pitch. Accordingly, regions of thedistal portion600 corresponding to the first andthird portions672,676 of thecoil670 are more flexible than a region of thedistal portion600 corresponding to thesecond portion674 of thecoil670. In some embodiments, the first and third pitches can be the same or different so long as the average pitch of the first andthird portions672,676 is less than the average pitch of thesecond portion674. Additionally, in some embodiments, thecoil670 or portions thereof can be made of or include a radiopaque or imaging material.
• FIG. 7 is a cross-sectional side view of adistal portion700 of a catheter shaft configured in accordance with the present technology. Thedistal portion700 can include aradiopaque marker717, aninner polymer structure714, anouter polymer structure716 surrounding at least a portion of theinner polymer structure714, and acoil770 wound around at least a portion of theinner polymer structure714. In the embodiment shown inFIG. 7, theinner polymer structure714 extends the length of thedistal portion700 such that theinner polymer structure714 terminates distally at an opening718 at the distal terminus of thedistal portion700. Theinner polymer structure714 defines a lumen that can be generally continuous with thelumen103 of any of the shaft embodiments described above with reference toFIGS. 1A-2.
• Theinner polymer structure714 can include a single layer of material or it can have two or more layers of the same or different materials. For example, as shown inFIG. 7, theinner polymer structure714 can include afirst layer712 and asecond layer713 surrounding thefirst layer712. As such, an inner surface of thefirst layer712 defines theshaft lumen103. Thesecond layer713 can be made of any of the materials described above with respect to theinner polymer structure714. Thefirst layer712 can comprise a lubricious polymer such as HDPE or PTFE, for example, or platinum, PEEK, PE, PP, or a copolymer of tetrafluoroethylene, such as FEP, a copolymer of tetrafluoroethylene with perfluoroethers, such as PFA (more specifically, perfluoropropyl vinyl ether or perfluoromethyl vinyl ether), or the like. Moreover, in some embodiments theinner polymer structure714 can be formed of a single layer (e.g., only thefirst layer712, only thesecond layer713, etc.), and in other embodiments theinner polymer structure714 can include more than two layers (e.g., three layers, four layers) depending upon the desired characteristics of the device.
• Theouter polymer structure716 directly contacts at least a portion of theinner polymer structure714 and encases at least a portion of thecoil770. For example, in the embodiment shown inFIG. 7, at least a portion of the surface of thecoil770 directly contacts thesecond layer713 of theinner polymer structure714, while a remaining portion of the coil's surface directly contacts theouter polymer structure716. In some embodiments theouter polymer structure716 extends along the length of thedistal portion700 such that a distal terminus of theouter polymer structure716 corresponds to the distal terminus of thedistal portion700. The outer polymer structure716 (and/or portions thereof) can be made of any of the materials described above with respect to theouter polymer structure116.
• Thecoil770 can be one or more round wires or flat ribbons helically wound around theinner polymer structure714. Thecoil770 can extend all or a portion of the length of thedistal portion700. For example, in the embodiment shown inFIG. 7, thecoil770 has a distal terminus that is aligned with or just proximal of theradiopaque marker717, and theradiopaque marker717 is proximal of the distal terminus of thedistal portion700. The pitch of adjacent turns of thecoil770 may be tightly wound so that each turn touches the succeeding turn or the pitch may be set such that thecoil770 is wound in an open fashion. The pitch of thecoil770 can be the same or vary along the length of thecoil770. For example, in the embodiment shown inFIG. 7, thecoil770 has afirst portion772, asecond portion774 distal of thefirst portion772, athird portion776 distal of thesecond portion774, and afourth portion778 distal of thethird portion776. Thefirst portion772 has a first pitch, thesecond portion774 has a second pitch greater than the first pitch, thethird portion776 has a third pitch less than the second pitch, and thefourth portion778 has a fourth pitch greater than each of the first and third pitches. Accordingly, regions of thedistal portion700 corresponding to the first andthird portions772,776 of thecoil770 are less flexible than regions of thedistal portion700 corresponding to the second andfourth portions774,778 of thecoil770.
• In some embodiments, the first and third pitches can be generally the same, and the second and fourth pitches can be generally the same and greater than the first and third pitches. In other embodiments, the first andthird portions772,776 can have the same and/or different pitches and/or the second andfourth portions774,778 can have the same and/or different pitches, so long as the average pitch of the first andthird portions772,776 is less than the average pitch of the second andfourth portions774,778. Additionally, in some embodiments, thecoil770 or portions thereof can be made of or include a radiopaque or imaging material.
• FIG. 8 is a cross-sectional side view of adistal portion800 of a catheter shaft configured in accordance with the present technology. Thedistal portion800 can include aradiopaque marker817, aninner polymer structure814, anouter polymer structure816 surrounding at least a portion of theinner polymer structure814, and acoil870 wound around at least a portion of theinner polymer structure814. In the embodiment shown inFIG. 8, theinner polymer structure814 extends the length of thedistal portion800 such that theinner polymer structure814 terminates distally at an opening818 at the distal terminus of thedistal portion800. Theinner polymer structure814 defines a lumen that can be generally continuous with thelumen103 of any of the shaft embodiments described above with reference toFIGS. 1A-2.
• Theinner polymer structure814 can include two or more layers. For example, as shown inFIG. 8, theinner polymer structure814 can include afirst layer812 and asecond layer813 surrounding thefirst layer812. As such, an inner surface of thefirst layer812 defines theshaft lumen103. Thesecond layer813 can be made of any of the materials described above with respect to theinner polymer structure814. Thefirst layer812 can comprise a lubricious polymer such as HDPE or PTFE, for example, or platinum, PEEK, PE, PP, or a copolymer of tetrafluoroethylene, such as FEP, a copolymer of tetrafluoroethylene with perfluoroethers, such as PFA (more specifically, perfluoropropyl vinyl ether or perfluoromethyl vinyl ether), or the like. Moreover, in some embodiments theinner polymer structure814 can be formed of a single layer (e.g., only thefirst layer812, only thesecond layer813, etc.), and in other embodiments theinner polymer structure814 can include more than two layers (e.g., three layers, four layers) depending upon the desired characteristics of the device.
• Theouter polymer structure816 directly contacts at least a portion of theinner polymer structure814 and encases at least a portion of thecoil870. For example, in the embodiment shown inFIG. 8, at least a portion of the surface of thecoil870 directly contacts thesecond layer813 of theinner polymer structure814, while a remaining portion of the coil's surface directly contacts theouter polymer structure816. In some embodiments theouter polymer structure816 extends along the length of thedistal portion800 such that a distal terminus of theouter polymer structure816 corresponds to the distal terminus of thedistal portion800. The outer polymer structure816 (and/or portions thereof) can be made of any of the materials described above with respect to theouter polymer structure116.
• Thecoil870 can be one or more round wires or flat ribbons helically wound around theinner polymer structure814. Thecoil870 can extend all or a portion of the length of thedistal portion800. For example, in the embodiment shown inFIG. 8, thecoil870 has a distal terminus that is aligned with or just proximal of theradiopaque marker817, and theradiopaque marker817 is proximal of the distal terminus of thedistal portion800. The pitch of adjacent turns of thecoil870 may be tightly wound so that each turn touches the succeeding turn or the pitch may be set such that thecoil870 is wound in an open fashion. The pitch of thecoil870 can be the same or vary along the length of thecoil870. For example, in the embodiment shown inFIG. 8, thecoil870 has afirst portion872, asecond portion874 distal of thefirst portion872, and athird portion876 distal of thesecond portion874. Thefirst portion872 has a first pitch, thesecond portion874 has a second pitch greater than the first pitch, and thethird portion876 has a third pitch less than the second pitch. Accordingly, regions of thedistal portion800 corresponding to the first andthird portions872,876 of thecoil870 are less flexible than a region of thedistal portion800 corresponding to thesecond portion874 of thecoil870. In some embodiments, the first and third pitches can be the same or different so long as the average pitch of the first andthird portions872,876 is less than the average pitch of thesecond portion874. Additionally, in some embodiments, thecoil870 or portions thereof can be made of or include a radiopaque or imaging material.
• In the embodiment shown inFIG. 8, thecoil870 has afirst portion872 having a first pitch, asecond portion874 having a second pitch greater than the first pitch, and athird portion876 have a third pitch less than the second pitch. The first and third pitches can be the same or different. Thethird portion876 can be distal of thesecond portion874, and thesecond portion874 can be distal of thefirst portion872.
III. SELECTED METHODS OF MANUFACTURE
• Theouter polymer structure116 can be constructed and disposed using any appropriate technique, for example, by extrusion, co-extrusion, ILC, coating, heat shrink techniques, heat bonding, casting, molding, fusing one or several segments of an outer polymer structure material end-to-end, or the like. Theouter polymer structure116 can be secured to theinner polymer structure114, thecoil170, theinner braid160, and/or theouter braid162 by any of the above techniques. In embodiments where theouter polymer structure116 is constructed independently of the other portions of theshaft106, theouter polymer structure116 may be thereafter secured to theinner polymer structure114, theinner braid160, theouter braid162, and/or thecoil170 using suitable techniques such as adhesive bonding, crimping, friction fitting, mechanically fitting, chemically bonding, thermally bonding, welding (e.g., resistance, RF, or laser welding), soldering, brazing, or the use of a connector member or material, or the like, or combinations thereof.
IV. CONCLUSION
• Several other embodiments of the technology can have different states, components, or procedures than those described herein. Moreover, it will be appreciated that specific elements, substructures, advantages, uses, and/or other features of the embodiments described with reference toFIGS. 1A-8 can be suitably interchanged, substituted or otherwise configured with one another in accordance with additional embodiments of the present technology. For example, any of the distal portions described with reference toFIGS. 3-8 can be combined with any of the elongated shafts and/or catheter systems described with references toFIGS. 1A-2. Furthermore, suitable elements of the embodiments described with reference toFIGS. 1A-8 can be used as standalone and/or self-contained devices. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other embodiments with additional elements, or the technology can have other embodiments without several of the features shown and described above with reference toFIGS. 1A-8.
• Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the exampled invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

Claims (20)

I/We claim:

1. A catheter, comprising:

an elongated shaft having a proximal portion and a distal portion, wherein an inner surface of the elongated shaft defines a lumen that extends distally from the proximal portion to an opening at a distal terminus of the distal portion;

wherein the distal portion includes—

an inner polymer structure having a first portion and a second portion positioned distal of the first portion along the length of the inner polymer structure, wherein the first portion has a first stiffness and the second portion has a second stiffness less than the first stiffness;

an outer polymer structure disposed around the inner polymer structure; and

a coil wound around the inner polymer structure and disposed within the outer polymer structure.

2. The catheter ofclaim 1 wherein a distal terminus of the second portion coincides with the opening at the distal terminus of the shaft.

3. The catheter ofclaim 1 wherein a distal terminus of the second portion is distal to a distal terminus of the coil.

4. The catheter ofclaim 1 wherein a distal terminus of the second portion is proximal to a distal terminus of the coil.

5. The catheter ofclaim 1 wherein the portion of the coil within the distal portion includes a first region and a second region distal to the first region, wherein the first region has a tighter pitch than the second region.

6. The catheter ofclaim 1 wherein the portion of the coil within the distal portion includes a first region, a second region distal to the first region, and a third region distal to the second region, wherein the first and third regions each have a tighter pitch than the second region.

7. The catheter ofclaim 1 wherein the portion of the coil within the distal portion includes a first region, a second region distal to the first region, and a third region distal to the second region, wherein the first and third regions each have a wider pitch than the second region.

8. The catheter ofclaim 1 wherein the inner polymer structure includes a first layer and a second layer surrounding the first layer, and wherein an inner surface of the first layer defines a portion of the lumen.

9. The catheter ofclaim 1 wherein the inner polymer structure includes a first layer and a second layer surrounded by the first layer, and wherein the first and second portions together comprise the first layer.

10. The catheter ofclaim 1, further including a radiopaque marker positioned around the inner polymer structure and/or outer polymer structure.

11. The catheter ofclaim 1 wherein a thickness of each of the inner polymer structure and the outer polymer structure are constant along the length of the distal portion.

12. The catheter ofclaim 1 wherein a thickness of at least one of the inner polymer structure and the outer polymer structure tapers along the length of the distal portion.

13. A catheter, comprising:

an elongated shaft having a proximal portion and a distal portion, wherein an inner surface of the elongated shaft defines a lumen that extends distally from the proximal portion to an opening at a distal terminus of the distal portion;

wherein the distal portion includes—

an inner polymer structure having a first portion and a second portion positioned distal of the first portion along the length of the inner polymer structure, wherein the first portion is made of a first material and the second portion is made of a second material different than the first material;

a radiopaque band positioned around a portion of the inner polymer structure;

an outer polymer structure disposed around the inner polymer structure and the radiopaque band; and

a coil wrapped around the inner polymer structure and disposed within the outer polymer structure, wherein the coil has a pitch that varies along the length of the coil.

14. The catheter ofclaim 13 wherein the portion of the coil within the distal portion includes a first region and a second region distal to the first region, wherein the first region has a tighter pitch than the second region.

15. The catheter ofclaim 13 wherein the portion of the coil within the distal portion includes a first region, a second region distal to the first region, and a third region distal to the second region, wherein the first and third regions have a tighter pitch than the second region.

16. The catheter ofclaim 13 wherein the portion of the coil within the distal portion includes a first region, a second region distal to the first region, and a third region distal to the second region, wherein the first and third regions have a wider pitch than the second region.

17. The catheter ofclaim 13 wherein the portion of the coil within the distal portion includes a first region, a second region distal to the first region, and a third region distal to the second region, wherein the first and third regions each have a wider pitch than the second region.

18. The catheter ofclaim 13 wherein a stiffness of the second portion is less than a stiffness of the first portion.

19. The catheter ofclaim 13 wherein the inner polymer structure includes a first layer and a second layer surrounding the first layer, and wherein an inner surface of the second layer defines a portion of the lumen.

20. The catheter ofclaim 13 wherein the inner polymer structure includes a first layer and a second layer surrounded by the first layer, and wherein the first and second portions together comprise the first layer.

Images