Patent Description:
In percutaneous transluminal coronary angioplasty (PTCA) procedures, a guiding catheter is advanced in the vasculature of a patient until the distal tip of the guiding catheter is seated in a desired coronary artery. A guidewire is advanced out of the distal end of the guiding catheter into the coronary artery until the distal end of the guidewire crosses a lesion to be dilated. A dilatation catheter, having an inflatable balloon on the distal portion thereof, is advanced into the coronary anatomy over the previously introduced guidewire until the balloon of the dilatation catheter is positioned across the lesion. Once positioned, the dilatation balloon is inflated with inflation fluid one or more times to a predetermined size at a suitable pressure to compress the stenosis against the arterial wall to open up the vascular passageway. Generally, the inflated diameter of the balloon is approximately the same diameter as the native diameter of the body lumen being dilated to complete the dilatation but not over expand the artery wall. After the balloon is deflated, blood resumes flowing through the dilated artery and the dilatation catheter and the guidewire can be removed therefrom.

In such angioplasty procedures, there may be restenosis of the artery, i.e., reformation of the arterial blockage, which necessitates either another angioplasty procedure, or some other method of repairing or strengthening the dilated area. To reduce the restenosis rate and to strengthen the dilated area, physicians may additionally or alternatively implant an intravascular prosthesis inside the artery at the site of the lesion. Such stents or scaffolds may be bare metal, polymeric, or coated with a drug or other therapeutic agent. Stents or scaffolds may also be used to repair vessels having an intimal flap or dissection or to generally strengthen a weakened section of a vessel. Stents or scaffolds are usually delivered to a desired location within a coronary artery in a contracted condition on a balloon of a catheter which is similar in many respects to a balloon angioplasty catheter and expanded to a larger diameter by expansion of the balloon. The balloon is deflated to remove the catheter with the stent implanted within the artery at the site of the dilated lesion. Coverings on an inner or an outer surface of the stent have been used in, for example, the treatment of pseudo-aneurysms and perforated arteries, and to prevent prolapse of plaque. Similarly, vascular grafts comprising cylindrical tubes made from tissue or synthetic materials such as polyester, expanded polytetrafluoroethylene, and DACRON® may be implanted in vessels to strengthen or repair the vessel, or used in an anastomosis procedure to connect vessels segments together. For details of example stents, see for example, <CIT>.

In addition to percutaneous transluminal angioplasty (PTA), PTCA, and atherectomy procedures, balloon catheters are also used to treat the peripheral system such as in the veins system or the like. For instance, a balloon catheter is initially advanced over a guidewire to position the balloon adjacent a stenotic lesion. Once in place, the balloon is then inflated, and the restriction of the vessel is opened, and a stent or scaffold can be delivered if desired. Likewise, balloon catheters are also used for treatment of other luminal systems throughout the body.

Typically, balloon catheters comprise a hollow catheter shaft with a balloon secured at a distal end. The interior of the balloon is in a fluid flow relation with an inflation lumen extending along a length of the shaft. Fluid under pressure can thereby be supplied to the interior of the balloon through the inflation lumen. To position the balloon at the stenosed region, the catheter shaft is designed in multiple parts to have suitable pushability (i.e., the ability to transmit force along the length of the catheter), trackability, and flexibility, to be readily advanceable within the tortuous anatomy of the vasculature. The catheter is also designed so that it can be withdrawn from the patient after delivery. Conventional balloon catheters for intravascular procedures, such as angioplasty and stent delivery, frequently have a relatively stiff proximal shaft section to facilitate advancement of the catheter within the body lumen, a mid-shaft section of an intermediate (or transition) flexibility, and a relatively flexible distal shaft section to facilitate passage through tortuous anatomy, such as distal coronary and neurological arteries, without damage to the vessel wall or damage to the stent, in the case of stent delivery.

Traditional catheter shafts are often constructed with inner and outer member tubing with an annular space therebetween for balloon inflation. In the design of catheter shafts, it is desirable to predetermine or control characteristics such as strength, stiffness and flexibility of various sections of the catheter shaft to provide desired catheter performance. This is conventionally performed by combining separate lengths of tubular members of different material and/or dimensions and then assembling the separate members into a single shaft length. However, the transition between sections of different stiffness or material can be a cause of undesirable kinking along the length of the catheter. Such kinking is particularly evident in rapid exchange (RX) catheters, wherein the proximal shaft section does not include the additional structure of a guidewire lumen tube. For example, a conventional RX catheter generally consists of a proximal hypotube having a single inflation lumen therethrough, a mid-shaft transition section, and a dual lumen or coaxial tube configuration at a distal end section having both a guidewire lumen and an inflation lumen therein. Known techniques to minimize kinking at the transition between the more rigid proximal section and the more flexible distal section include bonding two or more segments of materials having different flexibility together to form the shaft. Such transition bonds need to be sufficiently strong to withstand the pulling and pushing forces on the shaft during use.

To address the described issues, catheters having varied flexibility and/or stiffness have been developed with various sections of the catheter shaft that are specifically tailored to provide desired catheter performance. For example, each of <CIT>and <CIT>discloses a catheter having sections along its length which are formed from materials having a different stiffness; <CIT> to Solar discloses a catheter having an intermediate waist portion which provides increased flexibility along the catheter shaft; <CIT> discloses a catheter having a greater flexibility at its distal portion due to both a material and dimensional transition in the shaft; <CIT>discloses a catheter having a proximal portion with greater stiffness due to the application of a polymeric coating thereto; and <CIT>discloses a multilayer catheter shaft using a combination of a high Shore D durometer value material and a lower Shore D durometer value material to reduce kinking. <CIT> discloses a balloon catheter with a stepped skived hypotube, including a distal outer member extending from the hypotube to the balloon, the distal outer member formed by a midshaft member and a separate distal tubular shaft member.

However, one difficulty has been balancing the often competing characteristics of strength and flexibility of the catheter shaft. In addition, use of multiple shaft sections can be a cause of undesirable kinking along the length of the catheter, and the bonds between the sections can be a location of failure (e.g., rupture) if any defects in the bonds exist.

As such, there remains a need for a catheter having a shaft with an improved combination of characteristics such as strength, flexibility, ease of manufacture, and lower cost. There is also a need for a catheter that has improved trackability to facilitate further passage through tortuous anatomy, such as distal coronary arteries, while maintaining the ability to withdraw from the tortuous anatomy without failure.

The purpose and advantages of the disclosed subject matter will be set forth in and apparent from the description that follows, as well as will be learned by practice of the disclosed subject matter. Additional advantages of the disclosed subject matter will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.

The present invention provides a balloon catheter in accordance with claim <NUM> and a method in accordance with claim <NUM>.

To achieve these and other advantages and in accordance with the purpose of the disclosed subject matter, as embodied and broadly described, the disclosed subject matter includes balloon catheters and methods of making a balloon catheter. The balloon catheter as defined in claim <NUM> comprises an outer shaft including a hypotube and a monolithic single-layer distal outer member. The outer shaft has an inflation lumen defined therethrough. The monolithic single-layer distal outer member is necked to a reduced diameter along an entire length thereof introducing a linear orientation in the polymer material, and a proximal end of the monolithic single-layer distal outer member is coupled to the hypotube. A distal section of the hypotube comprises a skive defined by a first angled cut, an axial cut, and a second angled cut. The balloon catheter also includes a balloon in fluid communication with the inflation lumen. The balloon has a proximal balloon shaft coupled to a distal end of the monolithic single-layer distal outer member. The balloon catheter also includes a monolithic inner tubular member having a guidewire lumen defined therethrough. The monolithic inner tubular member extends distally from a proximal port in the monolithic single-layer distal outer member through the balloon to form a tip.

In some embodiments, the balloon further comprises a distal balloon shaft having an inner diameter. The distal balloon shaft can have a distal seal portion coupled to the monolithic inner tubular member and a proximal portion free of attachment to the monolithic inner tubular member. The length of the proximal portion of the distal balloon shaft can be at least about two times the inner diameter of the distal balloon shaft.

In some embodiments, the monolithic single-layer distal outer member comprises polyether block amide. The polyether block amide can have a Shore durometer hardness of about 63D to about 72D, for example about 72D.

In some embodiments, the reduced diameter comprises a first reduced outer diameter and a first reduced inner diameter along a proximal portion of the monolithic single-layer distal outer member and a second reduced outer diameter and a second reduced inner diameter along the distal end of the monolithic single-layer distal outer member. The first reduced outer diameter can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), the first reduced inner diameter can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), the second reduced outer diameter can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), and the second reduced inner diameter can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches). The length of the distal end of the monolithic single-layer distal outer member is about <NUM> to about <NUM>.

In some embodiments, the first angled cut of the skive can have a length of about <NUM>, the axial cut can have a length of about <NUM>, and the second angled cut can have a length of about <NUM>. The axial cut can have a height of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches). The second angled cut can define a distal edge height of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches). A proximal section of the hypotube can have an outer diameter of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) and an inner diameter of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches).

In some embodiments, a scaffold is mounted on the balloon. The scaffold can be bioresorbable.

According to another aspect of the disclosed subject matter, methods of making a balloon catheter are provided. An exemplary method includes necking a tubular member to form a monolithic single-layer distal outer member necked along an entire length thereof, providing a hypotube, coupling a proximal end of the monolithic single-layer distal outer member to the hypotube to form an outer shaft having an inflation lumen defined therethrough, and providing a balloon in fluid communication with the inflation lumen. The balloon has a proximal balloon shaft. The method also includes coupling the proximal balloon shaft to a distal end of the monolithic single-layer distal outer member and providing a monolithic inner tubular member having a guidewire lumen defined therethrough. The monolithic inner tubular member extends distally from a proximal port in the monolithic single-layer distal outer member through the balloon to form a tip.

In some embodiments, the balloon further comprises a distal balloon shaft having an inner diameter. The method can include coupling a distal seal portion of the distal balloon shaft to the monolithic inner tubular member and allowing a proximal portion of the distal balloon shaft to be free of attachment to the monolithic inner tubular member. The length of the proximal portion of the distal balloon shaft can be at least about two times the inner diameter of the distal balloon shaft.

In some embodiments, the tubular member is necked from a first outer diameter of about <NUM> (<NUM> inches) to a first reduced outer diameter of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) and from a first inner diameter of about <NUM> (<NUM> inches) to a first reduced inner diameter of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) along a proximal portion of the monolithic single-layer distal outer member. The tubular member can be necked from a first outer diameter of about <NUM> (<NUM> inches) to a second reduced outer diameter of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) and from a first inner diameter of about <NUM> (<NUM> inches) to a second reduced inner diameter of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) along the distal end of the monolithic single-layer distal outer member. The length of the distal end of the monolithic single-layer distal outer member can be about <NUM> to about <NUM>.

In some embodiments, the method can also include mounting a bioresorbable scaffold on the balloon and/or any of the features described herein above for the balloon catheter.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the disclosed subject matter claimed.

The accompanying drawings, which are incorporated in and constitute part of this specification, are included to illustrate and provide a further understanding of the disclosed subject matter. Together with the description, the drawings serve to explain the principles of the disclosed subject matter.

Reference will now be made in detail to the various exemplary embodiments of the disclosed subject matter, exemplary embodiments of which are illustrated in the accompanying drawings. The structure and method of making the disclosed subject matter will be described in conjunction with the detailed description of the balloon catheter.

In accordance the disclosed subject matter, a balloon catheter is provided. The balloon catheter includes an outer shaft including a hypotube and a monolithic single-layer distal outer member. The outer shaft has an inflation lumen defined therethrough. The monolithic single-layer distal outer member is necked to a reduced diameter along an entire length thereof, and a proximal end of the monolithic single-layer distal outer member is coupled to the hypotube. A distal section of the hypotube comprises a skive defined by a first angled cut, an axial cut, and a second angled cut. The balloon catheter also includes a balloon in fluid communication with the inflation lumen. The balloon has a proximal balloon shaft coupled to a distal end of the monolithic single-layer distal outer member. The balloon catheter also includes a monolithic inner tubular member having a guidewire lumen defined therethrough. The inner tubular member extends distally from a proximal port in the monolithic single-layer distal outer member through the balloon to form a tip.

The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the disclosed subject matter. For purpose of explanation and illustration, exemplary embodiments of the balloon catheter, and method of making thereof, in accordance with the disclosed subject matter are shown in <FIG>. While the present disclosed subject matter is described with respect to coronary indications, one skilled in the art will recognize that the disclosed subject matter is not limited to the illustrative embodiments, and that the product and methods described herein can be used in any suitable application.

For purpose of illustration, and not limitation, reference is made to an exemplary embodiment of a rapid exchange balloon dilatation catheter <NUM> shown in <FIG>. As shown in <FIG>, the balloon catheter <NUM> generally comprises an elongated catheter shaft <NUM> having a proximal shaft section <NUM> and a distal shaft section <NUM>. The catheter shaft <NUM> can have a variety of suitable configurations. For example, as illustrated in <FIG>, an outer shaft of the elongate catheter shaft <NUM> can include a hypotube <NUM> and a monolithic single-layer distal outer member <NUM>. The outer shaft including hypotube <NUM> and monolithic single-layer distal outer member <NUM> has an inflation lumen <NUM>, <NUM>, <NUM> defined therethrough, and the balloon catheter <NUM> includes a balloon <NUM> in fluid communication with the inflation lumen <NUM>, <NUM>, <NUM>. The balloon catheter also includes a monolithic inner tubular member <NUM> having a guidewire lumen <NUM>, <NUM> defined therethrough. The monolithic inner tubular member <NUM> extends distally from a proximal guidewire port <NUM> (shown <FIG>) in the monolithic single-layer distal outer member <NUM> through the balloon <NUM> to from a tip <NUM>.

As depicted in <FIG> and <FIG> for illustration, a proximal end <NUM> of the monolithic single-layer distal outer member <NUM> is coupled to the hypotube <NUM>. The distal end <NUM> of the monolithic single-layer distal outer member <NUM> is coupled to a proximal balloon shaft <NUM> of the balloon <NUM> (as described below). Accordingly, the single-layer distal outer member <NUM> is a monolithic construction that extends distally from the hypotube <NUM> to the balloon <NUM>. By contrast, typical balloon catheters include a separate midshaft portion bonded to the hypotube on one end and a separate distal outer shaft on the other end at a mid-lap seal. The monolithic construction of distal outer member <NUM>, in accordance with the disclosed subject matter, thus provides a jointless outer member extending from the hypotube all the way to the proximal balloon seal and eliminates the mid lap-seal, which is one potential location of failure in known balloon catheters. The monolithic construction of distal outer member <NUM>, in accordance with the disclosed subject matter, can provide a simpler design, easier and less expensive manufacturing, and less parts.

As embodied herein, the distal outer member <NUM> can comprise any suitable material. For example, the material can be a polyether block amide, commercially available under the trade name PEBAX®. The polyether block can have any suitable hardness, for example a Shore durometer hardness of about 63D to about 72D, preferably about 72D. Alternatively, nylons can be used alone or in combination (e.g., blended) with polyether block amide. While described herein as monolithic single layer distal outer member <NUM>, alternatively a multilayer monolithic construction can be used. In one embodiment, a first layer can comprise polyether block amide and the second layer comprise nylon. Alternatively, first and second layers can both comprise polyether block amide or nylon.

In accordance with the disclosed subject matter, the monolithic single-layer distal outer member <NUM> can be necked to a reduced diameter along an entire length thereof. In some embodiments, the distal outer member <NUM> can be necked by placing an extruded tube in a necking machine, as is known in the art. For example, the necking machine can use a heated die traversing along the length of the extruded tube having a mandrel therein to reduce the diameter of the distal outer member <NUM>, as shown in <FIG> for the purpose of illustration and not limitation. The outer diameter of the tube can be controlled by the size of the die and the inner diameter of the tube can be controlled by the diameter of the mandrel. After necking, the necked tube can be stabilized at <NUM> for about <NUM> minutes.

In some embodiments, the diameter of the tube as extruded can be reduced from an outer diameter ("OD") of about <NUM> (<NUM> inch) (<NUM> in <FIG>) and an inner diameter ("ID") of about <NUM> (<NUM> inch) (<NUM>) to a reduced diameter of about <NUM> (<NUM> inch) to about <NUM> (<NUM> inch) OD (<NUM>) and about <NUM> (<NUM> inch) to about <NUM> (<NUM>) ID (<NUM>) via necking. Thus, the wall thickness of the necked tubing is about <NUM> inches. In some embodiments, the reduced diameter comprises a first reduced outer diameter and a first reduced inner diameter along a proximal portion <NUM> of the monolithic single-layer distal outer member and a second reduced outer diameter and a second reduced inner diameter along the distal end <NUM> of the monolithic single-layer distal outer member. For example, the first reduced outer diameter can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), the first reduced inner diameter can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), the second reduced outer diameter can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), and the second reduced inner diameter can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches). The length of the distal end <NUM> of the monolithic single-layer distal outer member can be about <NUM> to about <NUM>.

In accordance with the disclosed subject matter, necking the distal outer member <NUM> can provide for more precise dimensions and decreased tolerances, can impart shear on the material, and can introduce partial orientation in the polymer material, which can increase the strength of the distal outer member without significantly effecting flexibility and provide for increased scaffold push. For example, it is desired for the rupture strength of the catheter shaft <NUM> to be greater than that of the balloon <NUM>. As embodied herein, for example, the burst pressure of the necked distal outer member <NUM> can be significantly greater than (e.g., about <NUM> MPa (<NUM> atm) more than, or about <NUM>% more than) that of the balloon <NUM>. Also, introduction of partial (e.g., linear) orientation in the polymer material of the distal outer member can provide more column strength, more push, and can still allow for some play (e.g., stretching or elongating) during withdrawal from the tortuous anatomy and decrease the likelihood of rupture or separation as compared to a shaft made of a fully oriented polymer material (e.g., blown). Furthermore, having the distal end <NUM> of distal outer member <NUM> necked to a smaller diameter than the rest of the distal outer member <NUM> allows the proximal balloon shaft <NUM> to more easily fit over the distal outer member <NUM> for heat bonding to a reduce profile (as described below).

As embodied herein, the guidewire lumen <NUM>, <NUM> can be defined by the monolithic inner tubular member <NUM> extending from the proximal port <NUM> through the monolithic single-layer distal outer member <NUM>. The space between the monolithic single-layer distal outer member <NUM> and the monolithic inner tubular member <NUM> can define inflation lumen <NUM> in fluid communication with the inflation lumen <NUM>. Thus, a coaxial annular configuration with the monolithic inner tubular member <NUM> positioned within the monolithic single-layer distal outer member <NUM> can be provided. Alternatively, the monolithic single-layer distal outer member <NUM> can be formed as a dual lumen member with the guidewire lumen and the inflation lumen defined therein.

For purpose of illustration and not limitation, <FIG> is a cross-section of the catheter <NUM> of <FIG> along the lines <NUM>-<NUM>. As depicted in <FIG>, the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM> includes an annular configuration. The inflation lumen <NUM> is defined by the annular space between the interior surface of monolithic single-layer distal outer member <NUM> and the exterior surface of the monolithic inner tubular member <NUM>, although a variety of suitable shaft configurations can alternatively be used including non-coaxial and multi-lumen extrusions. The transition from the circular to crescent to annular shape of the inflation lumens <NUM>, <NUM>, <NUM> allows for smooth flow without significant back pressure or resistance.

As embodied herein, the hypotube <NUM> can be a single lumen hypotube or similar tubular member of suitable rigidity and pushability. For example, the hypotube <NUM> can be a single piece construction tubular member. The hypotube <NUM> can have a proximal section <NUM> and a distal section <NUM> with an inflation lumen <NUM> and a longitudinal axis defined therethrough. The inflation lumen <NUM> of the hypotube <NUM> can comprise any suitable configuration, such as a substantially circular configuration as shown in <FIG>.

In accordance with the disclosed subject matter, the distal section <NUM> of the hypotube <NUM> can comprise a skive, which is a cut section of the hypotube that gradually reduces in dimension distally along its length. For example, as illustrated in <FIG> and <FIG>, the hypotube <NUM> can be skived at its distal section <NUM> with a stepped configuration. The stepped skive in accordance with the disclosed subject matter can improve the pushability (e.g., push force transmission) and resistance to kinking (e.g., by reducing kink points) of the catheter by providing a smoother transition between the hypotube and the more distal catheter components (e.g., the monolithic single-layer distal outer member as further discussed herein). The stepped skive can also provide improved support for the proximal port <NUM> described herein.

In some embodiments of the disclosed subject matter, as depicted in <FIG>, the skive of the hypotube <NUM> has three distinct sections including a first angled cut <NUM>, an axial cut <NUM>, and a second angled cut <NUM>. The hypotube <NUM> can reduce in cross-sectional dimension distally along the length of the skive. The first angled cut <NUM> can be at the distal end of the hypotube <NUM> and the axial cut <NUM> can be disposed between the first angled cut <NUM> and the second angled cut <NUM> proximate the proximal end of the skive. The first angled cut <NUM> can come to a point at the extreme distal end of the skive/hypotube, as depicted in <FIG>, or the distal end of the hypotube can include a blunt end as depicted in <FIG>. Other similar stepped configurations are contemplated.

In some embodiments, the first angled cut <NUM> and second angled cut <NUM> each can have a linear or straight angled configuration as depicted herein, or can be curved, such as a parabolic like curve. The first angled cut <NUM> and the second angled cut <NUM> can have the same angle of inclination or can have different angles of inclination. As depicted in <FIG>, for purposes of illustration, the first angled cut <NUM> and the second angled cut <NUM> can be substantially parallel with each other. In other embodiments, the first angled cut <NUM> extends at a first angle relative the longitudinal axis of the hypotube <NUM> and the second angled <NUM> cut extends at a second angle relative the longitudinal axis of the hypotube <NUM> such that the first angle is different from the second angle. For example, but without limitation, angle <NUM> can be steeper than angle <NUM>. In some embodiments, the angle for <NUM> is about <NUM>° and the angle for <NUM> is approx. Preferably, the angles should be shallow (e.g., close to <NUM>) to provide improved force transmission and reduce the chance of kinking.

As embodied herein, the first angled cut <NUM>, the axial cut <NUM>, and the second angled cut <NUM> can have the same or varying lengths, although the overall dimensions can preferably correspond with dimensions of the monolithic single-layer distal outer member <NUM> as described further below. For the purpose of illustration, <FIG> depict schematics of the distal section of the hypotube <NUM> for a coronary balloon dilation catheter, wherein the hypotube <NUM> has the first angled cut <NUM>, the axial cut <NUM>, and the second angled cut <NUM>. In the example of <FIG>, the first angled cut <NUM> has an axial length G between about <NUM> and about <NUM>, preferably about <NUM> plus or minus about <NUM>, for example about <NUM>. The first angled cut <NUM> of this embodiment has a blunt end which can have a distal height H ranging between about <NUM>% to about <NUM>% of the outer diameter of the hypotube <NUM>. In some embodiments, the height H can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), preferably about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), for example about <NUM> (<NUM> inches) plus or minus <NUM> (<NUM> inches).

As shown in <FIG>, the axial cut <NUM> can have an axial length A ranging between about <NUM> and about <NUM>, preferably about <NUM> plus or minus about <NUM>, for example about <NUM>. The axial cut <NUM> can have a height C, as depicted in <FIG>, that ranges between about <NUM>% to about <NUM>% of the outer diameter of the hypotube <NUM>. For example, the height C ranges between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), preferably about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches).

For the purpose of illustration, <FIG> is a cross-section of <FIG> along the lines 3B-3B. <FIG> depicts the outside diameter ØA and the inside diameter ØB of the hypotube <NUM>. In accordance with some embodiments of the disclosed subject matter, the skived hypotube <NUM> can have increased dimensions so as to form a thicker structure than previously described. For example, an increased thickness dimension can further improve column strength, push and kink resistance, and provide for enhanced scaffold control. For example, the inside diameter ØB of the hypotube <NUM> can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), preferably <NUM> (<NUM> inches) to about <NUM> (<NUM> inches). The outside diameter ØA of the hypotube <NUM> can be about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches), preferably about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches). The wall thickness of hypotube <NUM> can be between about <NUM> (<NUM> inches) and about <NUM> (<NUM> inches), preferably about <NUM> (<NUM> inches). <FIG> further depicts the height C of the axial cut <NUM> in relation to the outside diameter ØA and the inside diameter ØB.

As illustrated in <FIG>, the second angled cut <NUM> can have an overall height I when measured from a side of between about <NUM>% to about <NUM>% of the outer diameter of the hypotube <NUM>, preferably about <NUM>%. For example, the height I can about <NUM> (<NUM> inch) for a <NUM> (<NUM> inch) diameter hypotube. The second angled cut <NUM> can have a length S of about <NUM> to about <NUM>, preferably about <NUM> to about <NUM>, for example about <NUM>. <FIG> further depicts the height C of the axial cut <NUM> in relation to the outside diameter ØA and the inside diameter ØB.

Additionally, an end of one or more cuts can be radiused for transition purposes. For example, and as depicted in <FIG>, a proximal end of the second angled cut <NUM> can comprise a curved or radiused portion. The second angled cut <NUM> depicted herein includes a radius of approximately <NUM> (<NUM> inches) plus or minus about <NUM> (<NUM> inches). In the embodiment of <FIG>, the overall axial length of the skive with respect to the first angled cut <NUM>, the axial cut <NUM>, and the second angled cut <NUM> can range from about <NUM> to about <NUM>. Additional suitable dimensions of the skive are contemplated. Additional features of a skived hypotube can be found in <CIT>.

As depicted in <FIG> for purpose of illustration, the monolithic single-layer distal outer member <NUM> of the catheter <NUM> includes a guidewire lumen <NUM>, <NUM> and an inflation lumen <NUM>, <NUM> defined therethrough. The inflation lumen <NUM>, <NUM> of the monolithic single-layer distal outer member <NUM> is in fluid communication with the inflation lumen <NUM> of the hypotube <NUM>. Furthermore, at least a portion of the distal section of the hypotube <NUM> is disposed within the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM> with the inflation lumen <NUM> of the hypotube <NUM> in fluid communication with the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM>. The inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM> depicted herein comprises a generally crescent configuration at a proximal section thereof and the hypotube <NUM> is inserted into the inflation lumen <NUM>, as further discussed herein.

As embodied herein and as illustrated in <FIG>, an exterior surface of the monolithic single-layer distal outer member <NUM> can define a proximal port <NUM>. The proximal port <NUM> is spaced distally from the proximal end of the catheter <NUM>. The proximal port <NUM> is configured to receive a guidewire <NUM> within the guidewire lumen <NUM> of the monolithic single-layer distal outer member <NUM> and inner tubular member <NUM>. In some embodiments, the proximal port <NUM> is reinforced by the distal section of the hypotube <NUM> by disposing the distal section of the hypotube <NUM> proximate the proximal port <NUM> of the monolithic single-layer distal outer member <NUM>. In some embodiments, at least a portion of the axial cut <NUM> is disposed proximate to the proximal port <NUM> of the guidewire lumen <NUM>. The location of the proximal port <NUM> can depend upon various factors, such as the size of the balloon <NUM>, as further discussed herein. In some embodiments, second angled cut <NUM> is proximal the proximal port <NUM>, the axial cut <NUM> begins proximal the proximal port <NUM> and continues distal of the port <NUM> and first angled cut <NUM> is located distal of proximal port <NUM> and extends into a region where the monolithic single-layer distal outer member <NUM> and the inner tubular member are coaxial.

For purpose of illustration and not limitation, <FIG> is a cross-section of the catheter <NUM> of <FIG> along the lines <NUM>. As depicted in <FIG>, the hypotube <NUM> at this section is a single lumen member defining the inflation lumen <NUM> therethrough with a circular cross section. <FIG> is a cross-section of the catheter <NUM> of <FIG> along the lines <NUM>-<NUM>. In <FIG>, the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM> includes a substantially circular cross section. The inflation lumen <NUM> of the hypotube <NUM> is fluidly connected to the lumen <NUM> of the monolithic single-layer distal outer member <NUM>. As depicted in <FIG>, the second angled cut <NUM> is disposed within the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM>, as further discussed herein.

For purpose of illustration, <FIG> is a cross-section of the catheter <NUM> of <FIG> along the lines <NUM>-<NUM>. The monolithic single-layer distal outer member <NUM> at <NUM>-<NUM> includes a crescent like cross section for the inflation lumen <NUM>. With respect to <FIG>, the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM> transitions from a circular cross section at <FIG> to a crescent like cross section at <FIG>. The transition of the circular cross section of the monolithic single-layer distal outer member <NUM> to the crescent like cross section of the monolithic single-layer distal outer member <NUM> allows for a smooth transition in flow, as described further herein. The crescent like cross section of inflation lumen <NUM> can provide for a catheter with a reduced profile as compared to a catheter having a round inflation lumen at locations proximate the proximal port <NUM>.

As depicted in the cross section of <FIG>, the axial cut <NUM> can be disposed at least partially in the crescent inflation lumen <NUM>. The space around (e.g., above) the axial cut <NUM> can define the volume for inflation fluid flow. The corners of the crescent or "smiley" configuration can be rounded or otherwise provided in any suitable shape. The cross section also includes inner tubular member <NUM> and having guidewire lumen <NUM> and guidewire <NUM> disposed therein.

For purpose of illustration and not limitation, <FIG> is a cross-section of the catheter <NUM> of <FIG> along the lines <NUM>-<NUM>. <FIG> depicts a cross section of the monolithic single-layer distal outer member <NUM> in which the inflation lumen <NUM> has transitioned from the crescent configuration to an annular configuration. The first angled cut <NUM> interfaces with the monolithic single-layer distal outer member <NUM> and is positioned adjacent and below, as depicted in <FIG>, the guidewire lumen <NUM> as defined by inner tubular member <NUM> and having guidewire <NUM> disposed therein. The inflation lumen <NUM> is generally coaxial with the guidewire lumen <NUM>.

Thus, as embodied herein and as shown in <FIG>, the inflation lumen <NUM> of the hypotube <NUM> transitions from a circular cross section at section <NUM>-<NUM> of <FIG>, to a generally crescent or "smiley" configuration at section <NUM>-<NUM> of the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM> and then ultimately to an annular cross section at section <NUM>-<NUM> and <NUM>-<NUM>. However, the inflation lumen <NUM> can have alternative cross-sectional shapes as desired.

In accordance with the disclosed subject matter, the skive can serve as a male end section of the hypotube <NUM> and the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM> can serve as the female receiving end section. At least a portion of the stepped skive at the distal end section of the hypotube <NUM> can be configured to be received within the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM>. The skive of hypotube <NUM> can be disposed within the crescent or smiley shaped inflation lumen to fluidly connect the inflation lumen <NUM> of the hypotube <NUM> with the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM>. For example, and as embodied herein the skive portion of the hypotube <NUM> is disposed within the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM>, as depicted in <FIG> and <FIG>. The axial cut <NUM> can "float" within inflation lumen <NUM> and/or interface with a portion of a surface of the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM>. In alternative embodiments, at least the axial cut <NUM> can be press fit with the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM>. Furthermore, as embodied herein, the first angled cut <NUM> is inserted through the inflation lumen <NUM> of the monolithic single-layer distal outer member <NUM>, as depicted in <FIG>. Accordingly, the skive can assist in joining and reinforcing the hypotube <NUM> with the monolithic single-layer distal outer member <NUM>, while facilitating a smooth transition in flexibility and reduce kinking of the catheter.

In accordance with the disclosed subject matter, the monolithic single-layer distal outer member <NUM> can be bonded to the hypotube <NUM>. For example, the distal section of the hypotube <NUM> can have a roughened or textured outer surface to enhance the bond with the monolithic single-layer distal outer member <NUM>. The hypotube <NUM> can be concentrically aligned within the monolithic single-layer distal outer member <NUM>. Accordingly, the outer diameter or exterior surface of the hypotube <NUM> can be sized to fit concentrically within the interior surface of the monolithic single-layer distal outer member <NUM> at least at a distal section of the hypotube <NUM>. The hypotube <NUM> can be bonded to the monolithic single-layer distal outer member <NUM> along the roughened or textured portion, with the remainder of the hypotube (e.g., including the skive) free of attachments to the monolithic single-layer distal outer member <NUM>. Alternatively, in some embodiments, the hypotube <NUM> can be bonded with the monolithic single-layer distal outer member <NUM> along the length of the hypotube <NUM> or at portions along the length of the hypotube <NUM>.

In some embodiments, the hypotube <NUM> can be free of any outer coating or jacket, so as to have a bare exposed outer surface. In this manner, a hypotube <NUM> of larger cross section can be provided without increasing the profile of the proximal shaft section <NUM> as compared to a conventional rapid exchange catheters with a coated or jacketed hypotube. For example, the reduction in thickness by omitting a coating can allow for a proportional increase in both the outer diameter and thus the inner diameter of the tubular member. Thus, the overall profile of the catheter along a proximal end section can remain the same, but the dimensions of the inflation lumen therein can be increased. The increase in inner diameter can result in greater fluid flow for increased inflation or deflation (e.g., decreased inflation and deflation times) as compared to conventional catheters. In some embodiments, a thicker hypotube can be provided that can provide increased strength and pushability without substantially effecting profile and or inflation time as compared to known jacketed hypotubes. Further, the bare hypotube can also result in a better grip and a reduction in kinking.

As embodied herein, the catheter shaft <NUM> includes a monolithic inner tubular member <NUM> that defines the guidewire lumen <NUM>, <NUM> configured to slidably receive a guidewire <NUM> therein. As shown in <FIG> for illustration, the inner tubular member <NUM> can comprise one tube (i.e., monolithic and/or zero-transition) such that the inner tubular member <NUM> forms the tip <NUM>. The zero-transition inner tubular member <NUM> can provide continuous flexibility, direct force transfer, crossing of challenging anatomy with less force, and tactile feedback.

Thus, from the proximal end section to the distal end section, the catheter <NUM> embodied herein transitions from a single lumen (inflation lumen) configuration in the proximal shaft section <NUM> to a coaxial dual lumen (inflation lumen and guidewire lumen) configuration in the distal shaft section <NUM>. The area proximate the skive of hypotube <NUM> generally defines the juncture between the single lumen hypotube <NUM> and the coaxial dual lumen distal shaft section <NUM>.

As depicted in <FIG>, balloon <NUM> can be coupled to the monolithic single-layer distal outer member <NUM> and is in fluid communication with the inflation lumens <NUM>, <NUM>, and <NUM>. For purpose of illustration and not limitation, <FIG> is a cross-section of the catheter <NUM> of <FIG> along the lines <NUM>-<NUM>. As depicted in <FIG>, a balloon <NUM> is sealingly secured to the monolithic single-layer distal outer member <NUM> such that an interior of the balloon <NUM> is in fluid communication with inflation lumens <NUM>, <NUM>, and <NUM> and includes inner tubular member <NUM> and guidewire <NUM> therein. The balloon <NUM> is coupled to the monolithic single-layer distal outer member <NUM> by at least one of bonding, adhesive, lap joint, and butt joint or by other suitable configurations as known in the art, however, a lap joint formed via heat bonding is preferred.

As shown in <FIG> for illustration and not limitation, the balloon <NUM> can have a proximal balloon shaft <NUM>, a proximal cone portion <NUM>, a proximal shoulder <NUM>, a working length <NUM>, a distal shoulder <NUM>, a distal cone portion <NUM>, and a distal balloon shaft <NUM>. The balloon <NUM> can be coupled to the distal outer member <NUM> and monolithic inner tubular member <NUM> in any suitable manner. In some embodiments, the balloon <NUM> is coupled to the distal outer member <NUM> along a longitudinal length of the proximal balloon shaft <NUM> and coupled to the monolithic inner tubular member <NUM> along a longitudinal length of the distal balloon shaft <NUM>, as depicted in <FIG>. For example, the distal balloon shaft <NUM> can have a distal seal portion <NUM> coupled to the monolithic inner tubular member <NUM> and a proximal portion <NUM> of the distal balloon shaft free of attachment to the inner tubular member <NUM> as shown in <FIG> for the purpose of illustration and not limitation. The length of the proximal portion <NUM> of the distal balloon shaft free of attachment can be at least about two times the inner diameter <NUM> of the distal balloon shaft <NUM>.

As embodied herein and shown in <FIG> for the purpose of illustration and not limitation, the inner tubular member <NUM> can be a monolithic piece that forms the tip <NUM> of the catheter. The tip <NUM> includes a distal exposed portion <NUM> and a proximal portion <NUM> along the length of the distal seal portion <NUM> of the distal balloon shaft. In some embodiments, the length of the proximal portion <NUM> of the distal balloon shaft is about <NUM>% to about <NUM>% the length of the tip <NUM>. Furthermore, the length of the proximal portion <NUM> of the distal balloon shaft can be about <NUM>% to about <NUM>% of the combined length of the distal balloon shaft <NUM> and the distal exposed portion <NUM> of the tip.

In some embodiments, the tip length <NUM> is less than about <NUM> (including the distal exposed portion <NUM> and the proximal portion <NUM>). In some embodiments, the tip length can be about <NUM> to about <NUM> for <NUM> to <NUM> balloons. As discussed herein, the tip can taper distally and define a distal most tip <NUM> having an outer diameter of up to about <NUM> inches and inner diameter of about <NUM> inches minimum.

In some embodiments, the distal balloon shaft <NUM> can have inner and outer diameters that vary based on the size of the balloon: for <NUM> balloons, the inner diameter can be a minimum of <NUM> inches and the outer diameter can be about <NUM> inches; for <NUM> balloons, the inner diameter can be a minimum of <NUM> inches and the outer diameter can be about <NUM> inches; and for <NUM> balloons, the inner diameter can be a minimum of <NUM> inches and the outer diameter can be about <NUM> inches.

In some embodiments, the distal balloon shaft <NUM> can have a trim length <NUM> prior to sealing to the inner tubular member <NUM> of about <NUM> to about <NUM>. The distal seal portion <NUM> of the distal balloon shaft can have a length of about <NUM>. The proximal portion <NUM> of the distal balloon shaft free of attachment to inner tubular member <NUM> can have a length of about <NUM>.

The balloon cone length can vary based on the size of the balloon. For example, for <NUM> to <NUM> diameter balloons (of any length), the balloon cone length can be about <NUM>. For <NUM> diameter (of any length), the balloon cone length can be about <NUM>.

Inner tubular member <NUM> including tip <NUM> and balloon <NUM> configurations in accordance with the disclosed subject matter unexpectedly provide for improved trackability, allowing the catheter to advance further within the vascular system of a patient. For example, the length of the proximal portion <NUM> of the distal balloon shaft free of attachment to the inner tubular member <NUM> in accordance with the disclosed subject matter can provide for centering of the catheter (e.g., a coaxial position system) when traversing a bend in the vessel system, providing reduced stent damage as compared to known catheters due to contact with the side of the vessel (e.g., calcified lesions). Furthermore, known catheter systems having a distal balloon shaft entirely bonded to the inner tubular member and/or tip can have increased stiffness, which can reduce the trackability of the distal portion of the catheter as compared to catheters in accordance with the disclosed subject matter.

In accordance with the disclosed subject matter, the distal balloon shaft <NUM> of the balloon <NUM> can be coupled to the inner tubular member <NUM> in a plurality of suitable ways. For example, the distal balloon shaft <NUM> can be fusion bonded to the inner tubular member <NUM>, for example, by applying heat to at least a portion of the area of overlap. For illustration and without limitation, electromagnetic energy, such as thermal, laser, or sonic energy can be applied to the distal balloon shaft <NUM> to bond at least a portion of the distal balloon shaft <NUM> to the inner tubular member <NUM>. Heating the distal balloon shaft <NUM> can cause the polymeric material of the distal balloon shaft <NUM> to soften, or melt and flow, providing a distal seal portion <NUM> with a tapered configuration as shown in <FIG>.

In some embodiments, a heat shrink tubing (not shown) can be positioned around the outside of the distal balloon shaft <NUM>, which can have a trim length of about <NUM> to about <NUM> prior to melt bonding. The heat shrink tubing, also referred to as a "heat shrink sleeve," can be composed of a polymeric material configured to shrink when exposed to heat. <CIT>, discloses the use of a heat shrink sleeve in fabricating a catheter with a flexible distal end. The heat shrink tubing, when heated, shrinks and exerts an inward radial force on the distal balloon shaft <NUM>. With the polymer of the distal balloon shaft <NUM> in a molten or softened state, the diameter of the distal balloon shaft <NUM> can be reduced by the force exerted by the heat shrink tubing. After the balloon <NUM> is cooled, the heat shrink tubing can be removed. Heating can be accomplished, for example, by laser heating (e.g., using a CO<NUM> laser), contact heating (e.g., using aluminum nitride, resistance, RF), hot air, resistance heating, induction heating or the like. As embodied herein, for purposes of illustration and not limitation, a solid state laser can be used to heat the shrink tubing and soften the distal balloon shaft <NUM>. As a result, a portion of the outer surface of the distal balloon shaft <NUM>, in its softened or molten state, can be bonded to the inner tubular member <NUM>. Other catheter connections, such as the proximal balloon shaft <NUM> to the distal outer member <NUM> (e.g., via lap joint with proximal balloon shaft <NUM> over the distal outer member <NUM>), can be formed using the fusion bonding methods described herein.

In some embodiments, the exposed portion <NUM> of the tip can be tapered or rounded as shown in <FIG> during the same laser bonding process as forming the bond between the distal balloon shaft <NUM> and the inner tubular member <NUM> by traversing the laser along the length of the tip <NUM> and allowing the molten material to flow distally. The tapered tip can provide improved maneuverability to traverse tortuous anatomy. The distal balloon shaft <NUM> provides an area to seal <NUM> the distal end of the balloon <NUM> to the inner tubular member <NUM>. In some embodiments, a smaller length of the seal can provide improved flexibility to the distal section of the catheter but still provide suitable tensile strength. A smaller length of the seal can also reduce heat-induced damage to the balloon cone during the heat bonding process (which could result in rupture) by increasing the distance between the location of the seal and the balloon cone section. According to some embodiments of the disclosed subject matter, the distal balloon shaft <NUM> can be non-milled. Forming the balloon <NUM> with a distal seal portion <NUM> coupled to the inner tubular member <NUM> and a proximal portion <NUM> free of attachment to the inner tubular member <NUM> according to the disclosed subject matter can improve catheter trackability through tortuous vasculature or the like.

As depicted in <FIG> for the purpose of illustration and not limitation, the balloon <NUM> can comprise as a single layer of polymer material. For example, the balloon <NUM> can comprise a wide variety of suitable polymer materials, for example, nylons, co-polyamides such as polyether block amides (for example commercially available as PEBAX®), polyester, co-polyester, polyurethane, polyethylene, or the like. The balloon <NUM> can be formed of a polymeric material which is compatible with the material forming the outer surface of the shaft, to allow for fusion bonding, although the balloon <NUM> can alternatively or additionally be adhesively bonded to the shaft. In some embodiments, the balloon <NUM> can comprise a single layer of polyether block amide (e.g., commercially available as PEBAX®). The polyether block amide can have any suitable Shore durometer hardness, such as between about 63D and 72D, for example about 72D.

Alternatively, multilayered balloons can be used. For example, the balloon <NUM> can have a first layer made of a first polymer material having a first Shore durometer hardness, and a second layer made of a second polymer having a second Shore durometer hardness. In some embodiments, the first Shore durometer hardness can be greater than the second Shore durometer hardness, and the first layer can be an outer layer relative to the second layer. For example, the balloon <NUM> can have a first outer layer of polyether block amide (e.g., commercially available as PEBAX®) having a Shore durometer hardness of between about 55D and about 63D and a second inner layer of polyether block amide having a Shore durometer hardness of between about 70D and about 72D. In some embodiments, the balloon <NUM> has a first outer layer of PEBAX® 72D and a second inner layer of PEBAX® 63D. Details of suitable multilayer balloons are described in <CIT>, <CIT>, and <CIT>.

In accordance with the disclosed subject matter, the balloon can have wings and be folded as known in the art. For example, the balloon can have three folds for <NUM> to <NUM> diameter balloons. The balloon folds can improve the uniformity of stent or scaffold deployment.

As embodied herein, the balloon <NUM> can be a relatively high rupture pressure, non-compliant balloon, which in some embodiments has a rupture pressure of about <NUM> MPa (<NUM> atm) to about <NUM> MPa (<NUM> atm) or more, such that the balloon <NUM> can be inflated in the patient during a procedure at relatively high working pressure of about <NUM> MPa (<NUM> atm). The rated burst pressure of a catheter, calculated from the average rupture pressure, is the pressure at which <NUM>% of the catheters can be pressurized to without rupturing, with <NUM>% confidence. Generally, a balloon is inflated in the patient during a procedure at working pressure of about <NUM> MPa (<NUM> atm) to about <NUM> MPa (<NUM> atm), preferably about <NUM> MPa (<NUM> atm) to about <NUM> MPa (<NUM> atm). In some embodiments, the catheter with balloon <NUM> has a rated burst pressure of about <NUM> MPa (<NUM> atm) to about <NUM> MPa (<NUM> atm). In embodiments having a single layer balloon <NUM> of PEBAX® 72D, the rated burst pressure can be at least about <NUM> MPa (<NUM> atm). In embodiments having a balloon with a first outer layer of PEBAX® 72D and a second inner layer of PEBAX® 63D, the rated burst pressure can be about <NUM> atm and the nominal pressure can be about <NUM> atm. The balloon <NUM> can be any suitable size known in the art, e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> diameter.

Additional suitable materials, configurations, and methods of manufacture of the balloon <NUM> are provided in <CIT>, and <CIT>. Additional features proximate the balloon <NUM> can include markers (e.g., made of platinum/iridium and located both ends of the working length of the balloon), stents or scaffolds, and an atraumatic tip. Examples of such features and additional features include those described in <CIT>;<CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>.

In accordance with the disclose subject matter, the balloon <NUM> can have a stent or scaffold (not shown) mounted thereon for stent or scaffold delivery applications. The stent or scaffold can be made of any suitable material. For example, the scaffold can be bioresorbable and can be made of, for example, Poly(L-lactide) (PLLA). Alternatively, the stent can comprise a metal, e.g., a cobalt chromium alloy (e.g., L-<NUM> comprising Co-Cr-W-Ni). For bioresorbable scaffolds, markers, e.g., comprising platinum, such as beads at the ends of the scaffold can be used, which can help in positioning the scaffold during delivery. The scaffold (or stent) can include one or more coatings, for example a bioresorbable coating, for example of Poly (D, L-lactide) (PDLLA) can be used.

The stent or scaffold can have any suitable dimensions (e.g., having a diameter of <NUM>, <NUM>, or <NUM>) and be any suitable length, e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>. The stent or scaffold can have any suitable configuration as known in the art. The inner tubular member can include markers along its longitudinal length. For example, the inner tubular member can have a distal marker <NUM> and a proximal marker <NUM> along its length, as shown in <FIG>. In some embodiments, the middle of the markers are longitudinally aligned with the ends of stent or scaffold to improve placement of the stent or scaffold at the target site during treatment. The markers can be about <NUM> wide for <NUM> to <NUM> stents or scaffolds. The shaft (e.g., the hypotube) can also include proximal markers <NUM> and <NUM> proximal of the distal tip.

As embodied herein, the stent or scaffold can include a drug and/or or polymer coating as known in the art.

As depicted in <FIG> for purpose of illustration and not limitation, an adapter <NUM> (e.g., single arm) and a strain relief can be provided at the proximal end of the catheter <NUM> for access to the inflation lumens <NUM>, <NUM>, <NUM> collectively, and can be configured for connecting to an inflation fluid source (not shown). The balloon <NUM> can be provided at a distal end of the catheter and in fluid communication with the inflation lumens <NUM>, <NUM>, <NUM>. The distal end of the catheter can be advanced to a desired region of a body lumen in a conventional manner and balloon <NUM> inflated to perform a medical procedure, such as to dilate a stenosis and/or deliver a stent, scaffold, or the like. The catheter <NUM> is then withdrawn or repositioned for another procedure. <FIG> illustrates the balloon <NUM> in an inflated configuration.

In accordance with the disclosed subject matter, the catheter components can comprise a variety of suitable materials. For example, the hypotube <NUM> can be a more rigid material than the material of the distal outer member <NUM>. In some embodiments, the hypotube <NUM> can be a relatively high stiffness material including a metal, such as but not limited to stainless steel (e.g., <NUM>) , although a high durometer polymer can be used. The distal outer member <NUM>, coupled to the hypotube <NUM>, can be more flexible than the hypotube <NUM> and can comprise a more flexible material. In some embodiments, the distal outer member <NUM> can be a single layer and can comprise a polyether block amide (e.g., commercially available as PEBAX®) having as shore Durometer hardness of about 72D. Alternatively, the distal outer member <NUM> can comprise other polymers and/or can be a multilayer member made of one or more polymers, such as different Shore durometer hardness of polyamide or polyether block amides.

As embodied herein, the monolithic inner tubular member <NUM> can be a single layer or multilayer member made of one or more polymeric materials. For example, the inner tubular member <NUM> can comprise outer, inner and intermediate layers. The layers can be made of any suitable materials. For example, the outer layer can comprise a polyether block amide and/or nylon, the inner layer can comprise a lubricious polymer, and the intermediate layer can comprise a tie layer to bond the outer layer and the inner layer. In some embodiments, the outer layer comprises a polyether block amide, the inner layer comprises high density polyethylene (HDPE), and the intermediate layer comprises an ethylene acrylic acid adhesive polymer commercially available as Primacor®. The inner tubular member <NUM> can have any suitable dimensions, such as an outer diameter of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) and an inner diameter of about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches).

In accordance with the disclosed subject matter, a rapid exchange proximal port <NUM> can be formed in the distal outer member <NUM> at any suitable location along the length of the catheter using any technique known in the art. For example, an opening can be formed in the side wall of the distal outer member <NUM> and the inner tubular member <NUM> can be inserted through the opening to extend distally within the catheter (e.g., through the distal outer member and balloon). A mandrel or pressurizing fluid can be provided within the guidewire lumen <NUM> of the inner tubular member <NUM> to maintain the round shape of the guidewire lumen <NUM> during bonding, and optionally a shrink wrap can be provided over the distal outer member <NUM> proximate the opening. The distal outer member <NUM> can be fusion bonded, for example by heating with a laser, to the inner tubular member <NUM> within the interior of the distal outer member <NUM>. The crescent shape of the inflation lumen <NUM>, as shown in <FIG> for illustration, of the distal outer member <NUM> can be formed during the heating process by positioning a crescent shaped mandrel within the distal outer member <NUM> proximate the port. The heating process can provide a temperature sufficient to soften or melt the materials of the distal outer member <NUM> and the inner tubular member <NUM> to define the lumens therein. Shrink wrap material can be used to maintain the outer shape and dimension of the distal outer member <NUM> by the fusion process. The mandrel and shrink wrap can then be removed after the fusion or heating process is complete.

For purpose of illustration and not limitation, <FIG> depict cross-sections of the distal outer member <NUM> during manufacture. <FIG> depicts the cross section of the distal outer member <NUM> and inner tubular member <NUM> of a coaxial configuration, where the guidewire lumen <NUM> is concentric with the inflation lumen <NUM>, similar to <FIG>. <FIG> depicts a cross-section from the distal outer member <NUM> after the melting or fusion process depicting the inflation lumen <NUM> defined by a crescent mandrel. The dual lumen configuration of <FIG> can be formed as described above or by altemative techniques known in the art. For example, the distal outer member <NUM> can be molded to include a dual lumen member extending at least a length thereof for purpose of strength and transition from the proximal end section to the distal end section.

As embodied herein, after necking as described above, the catheter can be subsequently assembled, at least by sealingly securing a balloon <NUM> to a distal end of the distal outer member <NUM> via heat bonding, as described herein, such that the balloon <NUM> has an interior in fluid communication with the inflation lumen <NUM> of the distal outer member <NUM>. Portions of the catheter can be coated as known in the art, for example with a hydrophilic coating of poly(ethylene oxide) (PEO).

Catheters in accordance with the disclosed subject matter can be of any suitable dimensions, but preferably the shaft can have a reduced profile. For example, the proximal portion of the shaft can have a maximum diameter of about <NUM> inches, and the distal outer member can have a diameter of <NUM> (<NUM> inches) to about <NUM> (<NUM> inches). The crossing profile can be about <NUM> (<NUM> inches) (for a <NUM> x <NUM> balloon) and the tip entry profile can be about <NUM> (<NUM> inches). The working length of the catheter can be about <NUM>.

The burst pressure of balloon catheters having various sized balloons prepared in accordance with the disclosed subject matter were tested in accordance with IS010555-<NUM>:<NUM>, and the results are shown in Table <NUM>. The balloon catheters included a monolithic single-layer distal outer member <NUM> comprising PEBAX® 72D necked along its entire length and a hypotube comprising a skive defined by a first angled cut, an axial cut, and a second angled cut as described herein above. As demonstrated by the data in Table <NUM>, balloon catheters in accordance with the disclosed subject matter provide burst pressures significantly above the acceptance criteria (i.e., <NUM> atm), which is used for typical inflation pressures in medical procedures. For example, for <NUM>, <NUM>, and <NUM> diameter balloons, the average burst pressure was <NUM> atm, <NUM> atm, and <NUM> atm, respectively.

While the disclosed subject matter is described herein in terms of certain preferred embodiments, those skilled in the art will recognize that various modifications and improvements can be made to the disclosed subject matter without departing from the scope thereof. Moreover, although individual features of one embodiment of the disclosed subject matter can be discussed herein or shown in the drawings of the one embodiment and not in other embodiments, it should be apparent that individual features of one embodiment can be combined with one or more features of another embodiment or features from a plurality of embodiments.

In addition to the specific embodiments claimed below, the disclosed subject matter is also directed to other embodiments having any other possible combination of the dependent features claimed below and those disclosed above. As such, the particular features presented in the dependent claims and disclosed above can be combined with each other in other manners within the scope of the disclosed subject matter such that the disclosed subject matter should be recognized as also specifically directed to other embodiments having any other possible combinations. Thus, the foregoing description of specific embodiments of the disclosed subject matter has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosed subject matter to those embodiments disclosed.

Claim 1:
A balloon catheter (<NUM>) comprising:
an outer shaft (<NUM>) including a hypotube (<NUM>) and a monolithic single-layer distal outer member (<NUM>), the outer shaft having an inflation lumen (<NUM>, <NUM>, <NUM>) defined therethrough, wherein the monolithic single-layer distal outer member is made of a polymer material and is necked to a reduced diameter along an entire length thereof, wherein a linear orientation is introduced in the polymer material, wherein a proximal end of the monolithic single-layer distal outer member (<NUM>) is coupled to the hypotube (<NUM>), and wherein a distal section of the hypotube (<NUM>) comprises a skive defined by a first angled cut, an axial cut, and a second angled cut;
a balloon (<NUM>) in fluid communication with the inflation lumen (<NUM>, <NUM>, <NUM>), the balloon (<NUM>) having a proximal balloon shaft (<NUM>) coupled to a distal end of the monolithic single-layer distal outer member; and
a monolithic inner tubular member (<NUM>) having a guidewire lumen defined therethrough, the monolithic inner tubular member (<NUM>) extending distally from a proximal port (<NUM>) in the monolithic single-layer distal outer member (<NUM>) through the balloon (<NUM>) to form a tip.