Patent Description:
Various medical devices, for example, catheters, cannulas, sheaths, etc., are often introduced into a patient, for example, in an artery, vein, body cavity, or drainage site, to deliver fluids to or withdraw fluids from the patient. For example, a catheter or vascular sheath can be introduced into a patient's blood vessel using the Seldinger or a modified Seldinger technique. These techniques involve inserting an access needle into the patient's blood vessel and then inserting a guidewire through the needle and into the vessel. A dilator and sheath in combination or separately are inserted over the guidewire through tissue into the vessel. The needle can be removed before or after inserting the dilator and sheath. The dilator and guidewire are then removed and discarded. The sheath can be left in the vessel, for example, to deliver medical fluids to the patient, or a catheter or other medical article can be inserted through the sheath into the vessel to a desired location.

Various access devices for performing the Seldinger or a modified Seldinger technique are known. Some access devices provide the needle, dilator, and/or sheath coaxially disposed about one another. Some such devices provide mechanisms for confirming vascular access. <CIT> describes a pressure activated catheter valve. <CIT> describes a vascular access device. <CIT> describes an expandable transluminal sheath.

The access devices described herein advantageously provide improved mechanisms for safely achieving medical device placement within the vasculature. Without limiting the scope of this disclosure, its more prominent features will be discussed briefly. After considering this discussion, and particularly after reading the Detailed Description section below in combination with this section, one will understand how the features and aspects of these embodiments provide several advantages over prior access devices.

One aspect is an access device according to claim <NUM>, for placing a medical article within a body space.

The access device may comprise one or more of the following features: the valve element can be at least partially disposed between the distal portion of the inner cavity and the proximal portion of the inner cavity; the sealing portion can comprise a first sealing surface, the dilator hub can comprise a second sealing surface, and the first sealing surface can be against the second sealing surface to substantially seal the distal cavity portion from the proximal cavity portion when the valve element is in the closed position; at least one of the first sealing surface and the second sealing surface can extend entirely around an inner perimeter of the inner cavity; the sealing portion can comprise a raised portion; the raised portion can extend within the distal portion of the inner cavity when the valve element is in the closed position; the raised portion can comprise a substantially dome-like shape; the valve element can comprise a fold line along which the sealing portion and the attachment portion can bend with respect to each other; the valve element can comprise a flexible material with properties that reduce the likelihood of cold-setting when held in a flexed position for extended periods of time; movement of the guidewire in a proximal direction relative to the dilator can be inhibited when the valve element is in the closed position; the access device can comprise a sheath disposed about the dilator.

Another aspect is an access device according to claim <NUM>, for placing a medical article within a body space.

The access device may comprise one or more of the following features: the valve element can be at least partially disposed between a distal portion of the inner cavity and a proximal portion of the inner cavity; at least one of the first sealing surface and the second sealing surface can extend entirely around an inner perimeter of the inner cavity; the sealing portion can comprise a raised portion; the raised portion can extend within the dilator body when the valve element is in the first position; the raised portion can comprise a substantially dome-like shape; the valve element can comprise a fold line along which the sealing portion and the attachment portion can bend with respect to each other; the valve element can comprise a flexible material with properties that reduce the likelihood of cold-setting when held in a flexed position for extended periods of time; movement of at least one of the needle and the guidewire in a proximal direction relative to the dilator can be inhibited when the valve element is in the closed position.

One aspect is a method, the method is not covered by the subject-matter of the claims, of providing an access device for placing a medical article within a body space. The method includes providing a dilator having a hub and an elongated dilator body extending from the hub defining an inner cavity having a distal cavity portion and a proximal cavity portion. The dilator can further include a valve element comprising an attachment portion being supported within the inner cavity and a sealing portion extending into the inner cavity, the sealing portion comprising a first sealing surface, wherein the first seal surface is biased toward a first position against a second sealing surface on at least one of the dilator body and the dilator hub to substantially seal ta least a portion of the inner cavity from the dilator body, and wherein the sealing portion is movable from the first position to a second position when at least one of a needle and a guidewire is extended through the inner cavity. The method can further include providing a sheath configured to be coaxially disposed about the dilator.

The method can further include providing the access device comprising one or more of the following features: the valve element can be at least partially disposed between a distal portion of the inner cavity and a proximal portion of the inner cavity; at least one of the first sealing surface and the second sealing surface can extend entirely around an inner perimeter of the inner cavity; the sealing portion can comprise a raised portion; the raised portion can extend within the dilator body when the valve element is in the first position; the raised portion can comprise a substantially dome-like shape; the valve element can comprise a fold line along which the sealing portion and the attachment portion can bend with respect to each other; the valve element can comprise a flexible material with properties that reduce the likelihood of cold-setting when held in a flexed position for extended periods of time; movement of at least one of the needle and the guidewire in a proximal direction relative to the dilator can be inhibited when the valve element is in the closed position.

These and other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description of the disclosed embodiments, which refers to the attached figures. The invention is not limited, however, to the particular embodiments that are disclosed.

The foregoing and other features, aspects, and advantages of the embodiments of the invention are described in detail below with reference to the drawings of various embodiments, which are intended to illustrate and not to limit the embodiments of the invention. The drawings comprise the following figures in which:.

In various circumstances a physician may wish to introduce a catheter or sheath into a space within a patient's body, for example, a blood vessel or drainage site, to introduce fluids to the space or remove fluids from the space. Various access devices are known in the art. Examples of an improved access device are described in <CIT>, now <CIT>.

FIGURES 1A and 1B of <CIT> illustrate an access device <NUM> that can be used, for example, in performing the Seldinger or a modified Seldinger technique to introduce a catheter or sheath to a patient's blood vessel. While the access device is described herein in the context of vascular access, the access device also can be used to access and place a medical article (e.g., catheter or sheath) into other locations within a patient's body (e.g., a drainage site) and for other purposes (e.g., for draining an abscess).

The present disclosure of the access device is disclosed in the context of placing an exemplary single-piece, tubular medical article into a body space within a patient. Once placed, the tubular article can then be used to receive other medical articles (e.g., catheters, guidewires, etc.) to provide access into the body space and/or be used to provide a passage way for introducing fluids into the body space or removing (e.g., draining) fluids from the body space. In the illustrated embodiment, the tubular medical article is a sheath or catheter that is configured primarily to provide a fluid passage into a vein. The principles of the present invention, however, are not limited to the placement of single piece sheaths or catheters, or to the subsequent insertion of a medical article via the sheath or catheter. Instead, it will be understood in light of the present disclosure that the access device disclosed herein also can be successfully utilized in connection with placing one or more other types of medical articles, including other types of sheaths, fluid drainage and delivery tubes, and single or multi-lumen catheters directly in the patient or indirectly via another medical article.

For example, but without limitation, the access devices disclosed herein can also be configured to directly or indirectly place central venous catheters, peripherally inserted central catheters, hemodialysis catheters, surgical drainage tubes, tear-away sheaths, multi-piece sheaths, PICC lines, IV lines, scopes, as well as electrical conduit for wires or cables connected to external or implanted electronic devices or sensors. As explained above, the medical articles listed above may be directly placed in the patient via the dilator, needle, and guidewire of the access device or subsequently placed within the patient via a medical article that was placed within the patient via the dilator, needle, and guidewire of the access device.

Further, the embodiments disclosed herein are not limited to co-axial insertion of a single medical article. For example, two catheters may be inserted in the patient via an inserted sheath or a second catheter may be inserted in the patient via an inserted first catheter. Further, in addition to providing a conduit into the vessel or other body space, the medical article inserted via the dilator, needle, and guidewire can form a lumen that is in addition to the lumen(s) of the subsequently inserted medical article. One skilled in the art can also find additional applications for the devices and systems disclosed herein. Thus, the illustration and description of the access device in connection with a sheath (e.g., for micro puncture applications) is merely exemplary of one possible application of the access device.

<FIG> is a perspective view of an embodiment of an access device <NUM> that includes a dilator <NUM> coaxially aligned with a sheath <NUM>. A guidewire <NUM> is also shown. The components of the access device <NUM> illustrated in <FIG> include a dilator <NUM> and a sheath <NUM>. In the illustrated embodiment, the access device <NUM> also includes the guidewire <NUM>. The sheath <NUM> can be coaxially mounted on the dilator <NUM>. The telescoping nature of the access device's components can also be accomplished by arranging the components with their axes arranged substantially parallel rather than coaxially (e.g., a monorail-type design).

Each of these components includes a luminal fitting at a terminal end or transition (e.g., a hub) and elongated structure that extends from the fitting. Thus, in the illustrated embodiment shown in <FIG> and <FIG>, the dilator <NUM> includes a dilator shaft <NUM> that extends distally from a dilator hub <NUM>, and the sheath <NUM> includes a sheath body <NUM> that extends distally from a sheath hub <NUM>. In certain embodiments, the guidewire <NUM> includes a guidewire hub or cap.

<FIG> is side view of a needle <NUM> which can be employed to facilitate insertion of the guidewire <NUM> from <FIG> into a patient. <FIG> is a side cross-sectional view of the needle <NUM> of the embodiment depicted in <FIG> taken along line 2B-2B. The needle <NUM> includes a needle body <NUM> and a needle hub <NUM>. As best seen in <FIG>, the needle hub <NUM> is disposed on a proximal end of the needle body <NUM>. The needle body <NUM> terminates at a distal end near a distal portion <NUM> of the needle <NUM>, and the needle hub <NUM> lies at a proximal portion of the needle <NUM>.

The needle body <NUM> has an elongated tubular shape having a circular, constant-diameter interior bore <NUM> and a circular, constant-diameter exterior surface. In other embodiments, however, the needle body <NUM> can have other bore and exterior shapes (such as, for example, but without limitation, an oval cross-sectional shape). The interior or exterior of the needle <NUM> can also include grooves or channels. The grooves or channels may guide fluids within the needle bore either around or to certain structures of the needle <NUM> or within the needle <NUM> (e.g., around the guidewire <NUM>). In some embodiments, the grooves or channels may assist in maintaining a desired orientation of the needle <NUM> with respect to the dilator <NUM>.

The needle body <NUM> has a sufficiently long length to access a targeted subcutaneous body space and has a sufficient gauge size to withstand the insertion forces when accessing the body space without causing undue trauma. For many applications, the needle body <NUM> can have a length between <NUM>-<NUM> (e.g., between <NUM>-<NUM>). For example, to access a body space (e.g., a vessel) in the thorax of an adult human, the needle body <NUM> has a length of <NUM> or greater, a length of <NUM> or greater, and/or a length of <NUM> to <NUM>. The size of the needle <NUM> can be <NUM> gauge or smaller (e.g., between <NUM>-<NUM> gauge or between <NUM>-<NUM> gauge for micro-puncture applications (peripheral IVs)). For applications with a neonate, the length and gauge of the needle body <NUM> should be significantly shorter and smaller, for example between <NUM>-<NUM> and between <NUM>-<NUM> gauge. The needle body <NUM> can have a bevel tip <NUM> disposed on the distal portion <NUM>.

As explained below in greater detail, the guidewire <NUM> is introduced through a hollow portion <NUM> of the needle hub <NUM>, through the needle body <NUM>, and into a punctured vessel. After removing the needle <NUM> from the patient, the remaining guidewire <NUM> allows the healthcare provider to guide the dilator <NUM> and sheath <NUM> into the vessel.

<FIG> is a plan view of a dilator <NUM> that can be used with the access device <NUM> of <FIG> and includes a valve element <NUM> (not shown in <FIG> is a side cross-sectional view taken along the lines 3B-3B in <FIG> showing the valve element <NUM>. The illustrated dilator <NUM> comprises a dilator shaft <NUM>, a dilator hub <NUM>, and an inner cavity <NUM> including a distal portion <NUM> and a proximal portion <NUM>.

<FIG> is an enlarged perspective view of a portion of the dilator hub <NUM> illustrated in <FIG> when the valve element <NUM> is in a closed position. <FIG> is a side cross-sectional view of the dilator hub <NUM> depicted in <FIG> circled by line 4B-4B. <FIG> is an end view of the dilator hub <NUM> depicted in <FIG> looking in a distal direction. The dilator <NUM> includes an inner cavity <NUM>. In certain embodiments, the inner cavity <NUM> is configured to house the valve element <NUM>, as described herein. The inner cavity <NUM> can be sized and shaped so as to allow the valve element <NUM> to be housed in the dilator hub <NUM>. However, the valve element <NUM> need not reside within the dilator hub <NUM>. In certain embodiments, the valve element <NUM> resides on a proximal end (e.g., on top) of the dilator <NUM> or outside the dilator <NUM> as long as the guidewire <NUM> passes along the valve element <NUM>.

With continued reference to <FIG>, the valve element <NUM> can be configured to substantially seal at least a portion of the inner cavity <NUM> of the dilator hub <NUM> or other passage in the dilator through which the guidewire can pass. Valve element <NUM>, in some instances, can be positioned between a proximal portion <NUM> of inner cavity <NUM> and a distal portion <NUM> of inner cavity <NUM>, such that the valve element <NUM> can be configured to substantially seal the proximal portion <NUM> from the distal portion <NUM>. Portions <NUM>, <NUM> can comprise any of a variety of sizes and shapes and are shown with an approximately circular cross-sectional shape for illustrative purposes only. In some embodiments, distal portion <NUM> of inner cavity <NUM> comprises at least a region having a cross-sectional area that is less than proximal portion <NUM> to facilitate sealing of valve element <NUM> against distal portion <NUM>. In this arrangement, the valve element <NUM> can be configured as a one-way valve structure by substantially inhibiting fluid flow through the inner cavity <NUM> in a distal direction, while not substantially inhibiting the passage of articles (e.g. guidewire <NUM> as shown in <FIG>) through the inner cavity <NUM> in a proximal direction.

The valve element <NUM>, as illustrated, includes a sheath or disc that is configured to interact with at least a portion of the dilator hub <NUM> (e.g., sealing surface <NUM> described herein), as shown in <FIG>. The valve element <NUM> can be positioned over, against, or around any portion of the dilator hub <NUM> to seal at least a portion of the inner cavity <NUM>. The valve element <NUM> can be made of a single unitary body.

As shown in <FIG> and <FIG>, respectively, the valve element may have a first configuration and a second configuration (e.g., a closed position and an open position, respectively). Valve element <NUM> can be adapted to flex or move between the closed or substantially sealed position (e.g., as shown in <FIG>) and the open or unsealed position (e.g., as shown in <FIG>) through flexation, flexing, or flexing of a sealing portion <NUM> of the valve element <NUM>. Valve element <NUM> can move between the open and closed positions due to the passage of a device (e.g. guidewire <NUM>) through the dilator hub <NUM> and/or through operation by a user. In some embodiments, the valve element <NUM> can comprise an elastomeric material and/or flexible structure capable of deformation or movement as a device (e.g., a guidewire) abuts against and extends through the valve element <NUM>.

As illustrated in <FIG>, when the valve element <NUM> is in the first configuration (e.g., the closed position), the valve element <NUM> may be placed along a portion of the dilator hub <NUM>. For example, when in the closed position, a sealing surface <NUM> of the valve element <NUM> that is located on a distal surface of the sealing portion <NUM> can contact or otherwise engage with a corresponding sealing surface <NUM> of the dilator hub <NUM> that is located on a proximal-facing surface of the dilator hub <NUM>. The interaction of the respective sealing surfaces <NUM>, <NUM> can be sufficient to inhibit passage of fluids through the inner cavity <NUM> in the proximal and/or distal directions.

Valve element <NUM> can include an attachment portion <NUM> supporting the sealing portion <NUM>. The attachment portion <NUM> can be supported by a portion of the dilator hub <NUM>, such that the sealing portion <NUM> can extend (e.g., radially inwardly) into the inner cavity <NUM> and substantially seal an aperture within the inner cavity <NUM>. An attachment portion <NUM> of the valve element <NUM> can comprise any of a variety of materials with sufficient rigidity to support sealing portion <NUM>. The material may comprise sufficient flexibility to allow sealing portion <NUM> to flex or move between the open and closed positions, as described herein. The attachment portion <NUM> also can comprise a bio-compatible metal or plastic, or various composites or combinations thereof. Attachment portion <NUM> can comprise a material with reduced susceptibility to cold-setting. For example, in some applications, a medical article can be extended through inner cavity <NUM> with the valve element <NUM> in an open position and can be packaged together for a period of time within the dilator <NUM>, without compromising the valve features (e.g., its flexibility and ability to seal inner cavity <NUM> when in a closed position). For example, the access device can be packaged pre-assembled with the guidewire <NUM> coaxially disposed within the dilator <NUM>.

The valve element <NUM> can be sized and configured to extend along and enclose any portion and/or length of the inner cavity <NUM> of the dilator hub <NUM> to substantially seal the proximal portion <NUM> of the inner cavity <NUM> from the distal portion <NUM> of the inner cavity <NUM>. For example, the valve element <NUM> can be configured to be positioned over and enclose the distal portion <NUM> of the inner cavity <NUM> at a distal end of the proximal portion <NUM> of the inner cavity <NUM>. The valve element <NUM> can be configured such that the attachment portion <NUM> of the valve element <NUM> is positioned along a first portion of the dilator hub <NUM> and the sealing portion <NUM> of the valve element <NUM> is positioned along a second portion of the dilator hub <NUM> to substantially enclose the distal portion <NUM> of the inner cavity <NUM>. The valve element <NUM> can be configured to adhere to the dilator hub <NUM> when in the open position and/or the close position. In some embodiments, as described herein, the attachment portion <NUM> of the valve element <NUM> can comprise an adhesive to adhere at least to the dilator hub <NUM>.

The valve element <NUM> may comprise a restorative force biasing the valve element <NUM> towards a closed position. Notably, the restorative force can cause the sealing surface <NUM> to press against the sealing surface <NUM>. In some embodiments, this mechanism can be sufficiently resilient to withstand pressures associated with human blood vessels to inhibit blood from passing through the valve element <NUM> in a proximal direction when the valve element <NUM> is closed. As such, the mechanism advantageously inhibits a loss of blood through the valve element <NUM> when closed. This mechanism may, in some instances, be sufficient to maintain the placement of a device (e.g., a guidewire) within the dilator hub <NUM> when the device is inserted thought the dilator <NUM> (as shown in <FIG>). For example, the restorative force can cause the valve element <NUM> to engage the device to inhibit unintentional movement of the device relative to the dilator <NUM>.

In some embodiments, the valve element <NUM> is configured such that the sealing surface <NUM> of the sealing portion <NUM> is preloaded against sealing surface <NUM> of the dilator hub <NUM> such that valve element <NUM> is preloaded in the closed position, as described herein. This biasing can enhance the above-described inhibition of passage of matter in the distal and/or proximal directions. The biasing can help the valve element <NUM> inhibit passage of matter, such as the flow of fluid (e.g., blood or air) or passage of a device, in a proximal and/or distal directions (e.g., longitudinally) within inner cavity <NUM>. For example, the bias towards the closed position can be strong enough to resist a force (or cracking pressure) in the proximal and/or direction to open the valve element <NUM>. In some embodiments, the preload or bias of valve element <NUM> can be sufficient to prevent gas from being drawn distally through the inner cavity <NUM> and into a patient due to, for example, negative pressure created by a human during a normal pulse. Notably, drawing gas into a blood vessel can cause serious health effects such as an embolism.

<FIG> is a side cross-sectional view similar to <FIG> with the dilator <NUM> and the sheath <NUM> threaded over a guidewire <NUM> until the guidewire <NUM> abuts against and extends past the valve element <NUM> to cause the valve element <NUM> to move from the closed position to the open position. <FIG> is an enlarged perspective view of a portion of the dilator hub <NUM> illustrated in <FIG> looking in the distal direction when the valve element is in an open position. <FIG> is a side cross-sectional view of the dilator hub <NUM> depicted in <FIG> circled by line 6B-6B. In the illustrated embodiments, the dilator <NUM> has slid in a distal direction relative to the guidewire <NUM> until the valve element <NUM> engages the guidewire <NUM>. The sealing surface <NUM> of the valve element <NUM> can engage with an external surface of the guidewire <NUM> as the guidewire <NUM> passes through the dilator hub <NUM> and extends past the valve element <NUM>.

As discussed herein, the valve element <NUM> can be biased towards a closed position. The degree of bias of the valve element <NUM> towards the closed position can be selected so that the guidewire <NUM> is permitted to slide easily through the valve element <NUM> when the dilator <NUM> is threaded over the guidewire <NUM>. In certain embodiments, as the guidewire <NUM> is initially threaded through the dilator hub <NUM>, the valve element <NUM> abuts against the outer surface of the guidewire <NUM> so as to press against the guidewire <NUM>. The biasing force, in some instances, may be insufficient to meaningfully interfere with the of the guidewire <NUM> being threaded through the valve element <NUM>. That is, the biasing force of the valve element <NUM> on the guidewire <NUM> can still permit movement of the guidewire <NUM> relative to the valve element <NUM>. For example, the valve element <NUM> may not sufficiently resist passage of the guidewire <NUM> through the dilator hub <NUM> in a proximal direction relative to the dilator hub <NUM>.

The sealing portion <NUM> may include a raised portion, such as substantially dome-shaped portion adjacent to and/or along at least a portion of the sealing surface <NUM>. The dome-shaped portion can prevent or reduce the likelihood of contact between the sealing surface <NUM> and a device (e.g. the guidewire <NUM>), when the device is passing and/or extending through inner cavity <NUM>. For example, if the dilator <NUM> is stored with a device extending through the inner cavity <NUM>, the device may directly engage and/or contact the raised portion and not primarily with the sealing surface <NUM>. As such, the raised portion can prevent damage to the sealing surface <NUM> of the sealing element <NUM> caused by extended forceful contact with the device during storage and, thus, can extend the sealing capability and life of the valve element <NUM>.

Sealing portion <NUM> of the valve element <NUM> can comprise any of a variety of materials that can substantially seal inner cavity <NUM> when in contact with or biased against sealing surface <NUM>. In some embodiments, sealing portion <NUM> can comprise metal, plastic, rubber, or other suitable biocompatible materials such as polyisoprene, silicone, polyurethane, or other elastic polymers. In some embodiments, the sealing portion <NUM> can be coated or include other surface treatments, such as a siliconized surface to facilitate low-friction sliding of various elements along its surface (such as guidewire <NUM>). The attachment portion <NUM> and the sealing portion <NUM>, in some instances, can be formed of the same material, such that the valve element <NUM> can optionally be a single unitary piece. In some embodiments, the valve element <NUM> can comprise a separate biasing element configured to bias the valve element <NUM> towards the closed position.

The valve element <NUM> can be formed in a number of different ways, such as by molding (e.g., injection), stamping and the like, and can be formed separately or integrally with the dilator hub <NUM>. The attachment portion <NUM> and the sealing portion <NUM> can be attached to each other and/or the dilator hub <NUM> in a variety of ways, such as with adhesive, bonding (e.g., ultrasonic, thermal, etc.), fasteners, overmolding, and the like. A primer or non-stick coating or surface treatment can be applied to the attachment portion <NUM> and/or the sealing portion <NUM> to facilitate their attachment to each other during the manufacturing thereof. With respect to the bending properties of the sealing portion <NUM>, described above, in some embodiments the sealing portion <NUM> can be pretreated to have certain mechanical characteristics prior to its combination with the attachment portion <NUM>.

The valve element <NUM>, as depicted by way of the attachment portion <NUM>, can attach to the dilator hub <NUM> by a variety of means. In some embodiments, it can be glued or bonded to the dilator hub <NUM>. In other embodiments, the attachment portion <NUM> can attach to the dilator hub <NUM> by molding or overmoulding. In further embodiments, the attachment portion <NUM> can be molded integrally with the dilator hub <NUM> (or a portion thereof). When formed integrally, it may be desirable to give the dilator hub <NUM> a substantially greater thickness than the attachment portion <NUM>, such that the dilator hub <NUM> maintains a higher rigidity. In other embodiments, the attachment portion <NUM> can attach to the dilator hub <NUM> by a mechanical compression, such as where the dilator hub <NUM> includes a groove that receives the attachment portion <NUM>, and allows it to be press-fit into position.

In some embodiments, the valve element <NUM> may engage the dilator hub <NUM> through an attachment member <NUM>, as shown in <FIG>. The valve element <NUM> may be attached to an attachment member <NUM>, which is inserted into the inner cavity <NUM> of the dilator hub <NUM>. The attachment member <NUM> can include a central bore configured to engage the sealing portion <NUM> of the valve element <NUM> when the valve element <NUM> is in a closed position. A distally-facing surface of the attachment member <NUM> can be substantially straight or flat to engage the sealing surface <NUM> of the dilator hub <NUM>. The attachment member <NUM> is placed against the sealing surface <NUM> so that in a closed position, the sealing portion <NUM> seals against the attachment member <NUM> rather than the sealing surface <NUM>. The attachment member <NUM> can be made of a relatively soft material and can be soft enough to allow the attachment member <NUM> to be press-fit into the inner cavity <NUM>.

The attachment member <NUM> can be substantially circular, or donut-shaped, allowing flexibility in its rotational position within the dilator hub <NUM>. However, in other embodiments the attachment member <NUM> can be rotationally fixed within the dilator hub <NUM>, i.e., with a non-circular insert and a corresponding non-circular receiving portion in the dilator hub <NUM>. Further, the outer edge of the attachment member <NUM> can be shaped to substantially match the sealing surface <NUM> of the dilator hub <NUM> to form a seal between the two that at least hinders the escape of fluids therethrough. In some embodiments, a taper along the attachment member <NUM> and/or within the dilator hub <NUM> can facilitate a seal between the attachment member <NUM> and the dilator hub <NUM>.

The attachment member <NUM> can advantageously compensate for possible molding imperfections and/or misalignment in the manufacture and assembly of the dilator hub <NUM>, for example, due to being constructed from a relatively soft and compliant material. The attachment member <NUM> may also advantageously reduce the size of the aperture to be sealed by the sealing portion <NUM> compared to the sealing surface <NUM>. Additionally, the attachment member <NUM> can act as a seal around a device inserted through the dilator hub <NUM> to maintain a seal when the valve element <NUM> is in an open position to accommodate the device. The attachment member <NUM> can therefore act as a seal independent of the sealing portion <NUM>. In some embodiments, the attachment member <NUM> can stretch to accommodate and/or conform to various devices that can be introduced through the dilator hub <NUM>.

In some embodiments, the sealing portion <NUM> can be made of a relatively hard material, for example, polyurethane or polycarbonate. Inclusion of a relatively soft attachment member <NUM> can advantageously allow the sealing portion <NUM> to be made of a relatively hard material because the more compliant attachment member <NUM> can compensate for molding imperfections, misalignment, and the like for which a relatively hard sealing portion <NUM> may not be able to compensate as effectively. The relatively hard material can advantageously reduce possible damage to the valve element <NUM> and better resist tearing and/or other wear. Such tearing or wear can adversely affect the effectiveness of the seal.

The attachment member <NUM>, in some instances, can be removably engaged with at least a portion of the dilator hub <NUM> so that the attachment member <NUM> can move in or out of the inner cavity <NUM>. For example, the attachment member <NUM> may be removably held within the inner cavity <NUM> via any suitable interaction (e.g., interference, engagement, friction, mechanical coupling, adhesion, etc.). The attachment member <NUM> may be sufficiently engaged with the dilator hub <NUM> to prevent unintentional removal of the attachment member <NUM> from the inner cavity <NUM>. In some embodiments, once the guidewire <NUM> abuts against the valve element <NUM>, further proximal movement of the guidewire <NUM> relative to the dilator <NUM> may be insufficient to overcome the interactive force removably holding the attachment member <NUM> within the inner cavity <NUM>. For example, the attachment member <NUM> may remain within the inner cavity <NUM> after the guidewire <NUM> presses against and extends past the valve element <NUM>. In certain embodiments, one or more walls such as sealing surface <NUM> of the inner cavity <NUM> prevent distal movement of the attachment member <NUM> relative to the inner cavity <NUM>.

The dilator hub <NUM> may include locking structures along a proximal region and/or a distal region <NUM> of the dilator hub <NUM>. Each locking structure may be a luer type or other type of connection. In the illustrated embodiment, the dilator hub <NUM> comprises a luer connection <NUM>. In some embodiments, the luer connection <NUM> (e.g., a male luer slip connector) can be configured to engage to the sheath hub <NUM> (e.g., a female luer slip connector) on the sheath <NUM> illustrated in <FIG>. Additionally, the male-female lure slip connectors on these components can be reversed.

The color of the dilator <NUM> may be selected to enhance the contrast between the blood or other fluid and the dilator <NUM>. For example, in some applications, during blood flash, blood is observed flowing between the dilator <NUM> and the sheath <NUM> to confirm proper placement in a blood vessel. To increase the visibility of the fluid as the fluid flows between the sheath <NUM> and dilator <NUM>, the sheath <NUM> is preferably manufactured from a clear or transparent material with the dilator <NUM> having a color that contrasts with the color of the fluid. For example, the dilator <NUM> may have a white color to enhance its contrast with red blood. Other colors of dilator <NUM> could be employed depending on the color of the fluid and the degree of contrast desired. Further, only a portion of the dilator <NUM> in the region of the blood flash can have the contrasting color with the remainder having a different color.

In use, the dilator <NUM> expands an opening or passage created by the needle <NUM>. The expanded passage facilitates subsequent introduction of the sheath <NUM>. The needle <NUM> allows the introduction of the guidewire <NUM>, and subsequently the dilator <NUM> and finally the sheath <NUM> into a patient's body.

<FIG> is an end view of a sheath <NUM> looking in the distal direction that can be used with the access device <NUM> of <FIG>. <FIG> is a side view of the sheath <NUM> depicted in <FIG>. The sheath <NUM> may comprise a sheath body <NUM>, a sheath hub <NUM>, a distal region <NUM>, and a proximal region <NUM>. The sheath body <NUM> may be made partially or completely from clear, translucent, transparent, or semi-opaque material. The sheath body <NUM> can also include one or more radiopaque markers, such as, for example, barium sulfate stripes. In a preferred embodiment, the sheath includes two such radiopaque stripes disposed on diametrically opposite sides of the body <NUM>.

The sheath body <NUM> may be a single piece sheath through which a catheter or other medical article (e.g., guidewire <NUM>) is inserted through the sheath <NUM>. In such an embodiment, the sheath body <NUM> forms a conduit for insertion of the catheter or other medical article. In addition to providing a conduit, the sheath <NUM> or a portion of the sheath can form a lumen that is in addition to the lumen(s) of the catheter. For example, an equivalent to a triple lumen catheter can be formed by inserting a dual lumen catheter through the sheath body <NUM> with the sheath body <NUM> itself forming a third lumen. The sheath body <NUM> can be manufactured from a clear or at least somewhat transparent material to allow the physician or healthcare provider to see blood flowing within the dilator <NUM> through the sheath body <NUM>.

In some embodiments, for example as shown in <FIG>, the sheath can be a splittable sheath 26A. For example, it may be advantageous to remove a portion or the entire sheath body <NUM> depending on the type of catheter or medical article that is to be inserted into the vessel after employing the access device <NUM>. For example, after the catheter or other medical article is inserted into the vessel, a portion of the sheath body <NUM> can be separated or peeled-away and removed to reduce clutter at the access site. A peel-away sheath can include perforations, serrations, skives, or other structures, or include other materials (e.g., PTFE with bismuth) to allow the physician or healthcare provider to remove easily a portion or the entire sheath body <NUM>.

The sheath hub <NUM> may include a luer slip connection <NUM>. The luer slip connection <NUM> may comprise a locking or attaching structure that mates or engages with a corresponding structure. For example, the luer slip connection <NUM> can be configured to engage with the luer connection <NUM> of the dilator hub <NUM>.

The sheath hub <NUM>, as best seen in <FIG>, preferably is designed so that the luer connection <NUM> of the dilator hub <NUM> can enter the sheath hub <NUM> substantially unobstructed. However, in use, once the sheath hub <NUM> is placed at a desired location over the dilator shaft <NUM>, the physician or healthcare provider can push, pull, or twist the sheath hub <NUM> and possibly disengage or engage the luer slip connection <NUM> with a corresponding connector on another medical article. The luer slip connection <NUM> creates a mechanical fit so that the dilator hub <NUM> and the sheath hub <NUM> are releasably interlocked. The sheath hub <NUM> engages with the corresponding luer connection <NUM> on the dilator hub <NUM>. The locked position can be disengaged or engaged by pulling, squeezing, pushing or twisting the dilator hub <NUM> relative to the sheath hub <NUM>.

In additional embodiments, the sheath hub <NUM> may comprise radially extending wings or handle structures to allow for easy release and removal of the sheath body <NUM> from other parts of the access device <NUM>. In some applications, the wings are sized to provide the healthcare provider with leverage for breaking apart the sheath hub <NUM>. The sheath hub <NUM> and/or the sheath body <NUM> may comprise two or more portions (e.g., halves) connected by a thin membrane. The membrane can be sized to hold the two or more portions of the sheath hub <NUM> and/or sheath body <NUM> together until the healthcare provider decides to remove the sheath hub <NUM> and/or sheath body <NUM> from the access device. The healthcare provider manipulates the wings to break the membrane and separate the sheath hub <NUM> into removable halves.

<FIG> is a side cross-sectional view of the access device <NUM> after the access device <NUM> has been threaded over the guidewire <NUM>. Thus, in the illustrated embodiment, the dilator <NUM> includes the dilator shaft <NUM> that extends distally from the dilator hub <NUM>, and the sheath <NUM> includes the sheath body <NUM> that extends distally from the sheath hub <NUM>. In certain embodiments, the guidewire <NUM> includes a guidewire hub or cap (not shown). In the illustrated embodiment, the dilator <NUM> and the sheath <NUM> are releasably interlocked at a proximal end of the access device <NUM>. In some embodiments, the releasable interlock between the dilator <NUM> and the sheath <NUM> is a linear interlock where the sheath <NUM> is locked to the dilator <NUM>. The relative positioning of the terminal ends of the dilator <NUM> and the sheath <NUM> are shown in <FIG>. For example, the terminal end of the dilator body <NUM> extends beyond the terminal end of the sheath <NUM>.

<FIG> is a cross-sectional view of the needle <NUM> illustrated in <FIG> penetrating a body <NUM>. <FIG> is an enlarged partial cross-sectional view from <FIG> of a distal end of the needle <NUM>. In <FIG>, the needle <NUM> has penetrated the vasculature. <FIG> is an enlarged partial cross-sectional view from <FIG> of a distal end of the needle <NUM>. In use, the bevel tip <NUM> enters the blood vessel <NUM>.

<FIG> is a cross-sectional view similar to <FIG> where a guide wire <NUM> has been fed through the needle <NUM> and into the blood vessel <NUM> of the patient. Once the physician or healthcare provider has located the needle <NUM> within the target blood vessel <NUM>, the physician or healthcare provider feeds the guidewire <NUM> into the vasculature. The needle <NUM> is held still while the guidewire <NUM> is fed through the needle <NUM> and into the patient. During the insertion procedure, the guidewire <NUM> passes through the interior bore <NUM> of the needle <NUM>.

A guide wire advancer as known in the art may be employed when feeding the guidewire <NUM> through the needle <NUM>. For example, if the guidewire <NUM> has a curved or J tip, an advancer may be employed to straighten the tip facilitating feeding of the guidewire <NUM> into the interior bore <NUM> of the needle <NUM>. <FIG> is a cross-sectional view similar to <FIG> except the guidewire <NUM> has been extended further into the vasculature of the patient.

<FIG> is a cross-sectional view similar to <FIG> where the needle <NUM> has been removed and the dilator <NUM> and the sheath <NUM> have been slid along the exterior portion of the guidewire <NUM> causing the valve element <NUM> to be moved into the open position. <FIG> is an enlarged partial cross-sectional view from <FIG>. The sealing portion <NUM> of the valve element <NUM> within the inner cavity <NUM> of the dilator <NUM> has effectively been moved in a proximal direction relative to the dilator <NUM> as the dilator <NUM> is slid along the exterior portion of the guidewire <NUM>.

<FIG> is a cross-sectional view similar to <FIG> where the dilator <NUM> and sheath <NUM> have been slid further along the exterior portion of the guidewire <NUM> and into the patient's vasculature. During threading of the sheath <NUM> and the dilator <NUM> over the guidewire <NUM> and into the blood vessel <NUM>, the guidewire <NUM> can freely slide along the valve element <NUM>. The dilator <NUM> and sheath <NUM> may be inserted into the patient's vasculature at any one of a variety of angles relative to the body <NUM> of the patient. The angle of insertion shown in <FIG> is for schematic illustrative purposes only. In some embodiments, the dilator <NUM> and the sheath <NUM> may be introduced at a lower profile angle relative to the body <NUM> when compared to the angle of insertion shown in <FIG>. In this arrangement, the dilator <NUM> and the sheath <NUM> can be inserted such that a distal end portion of the dilator <NUM> and/or the sheath <NUM> need not bend (or bend only slightly) once inserted into the blood vessel <NUM> (e.g., as compared to the dilator <NUM> and sheath <NUM> shown in <FIG>).

<FIG> is a cross-sectional view similar to <FIG> where the guidewire <NUM> has been withdrawn from the dilator <NUM> and the sheath <NUM>. As described herein, the valve element <NUM> can be biased towards the center of the dilator hub <NUM>. The bias can cause the valve element <NUM> to move towards the closed position when the guidewire <NUM> is removed. Accordingly, upon removal of the guidewire <NUM>, the valve element <NUM> may move to the closed position to substantially seal at least the distal portion <NUM> of the inner cavity <NUM> by abutting against the sealing surface <NUM>, as shown in <FIG>.

<FIG> is a cross-sectional view similar to <FIG> where the dilator <NUM> has been removed from the patient and the sheath <NUM>. The sheath <NUM> is left properly inserted within the blood vessel <NUM>. The dilator <NUM> may be removed after or in concert with removal of the guidewire <NUM>.

<FIG> is a cross-sectional view similar to <FIG> where a catheter <NUM> is aligned with the sheath <NUM> for insertion into the patient's vasculature. <FIG> is a cross-sectional view similar to <FIG> where the catheter <NUM> has been inserted through the sheath <NUM> and into the patient's vasculature, specifically the targeted blood vessel <NUM>.

<FIG> is a cross-sectional view similar to <FIG> where two portions of the sheath <NUM> are being peeled away from each other to remove the sheath <NUM> from encircling the catheter <NUM>. The sheath <NUM> is splittable along one or more split lines. A splittable sheath <NUM> provides the advantage of allowing a portion of or the entire sheath body <NUM> to be removed depending on the type of catheter or medical article that is to be inserted into the vessel after employing the access device <NUM>. For example, after the catheter <NUM> is inserted into the blood vessel <NUM>, a portion of the sheath body <NUM> is separated or peeled-away and removed to reduce clutter at the access site. The peel-away sheath <NUM> can be first slid in a proximal direction along the catheter <NUM> until the sheath <NUM> is removed from the patient and then split apart. Alternatively, the sheath <NUM> can be initially split prior to the entire sheath <NUM> being removed from the patient. After the remainder of the sheath <NUM> is removed from the patient, the physician or healthcare provided can continue splitting the sheath <NUM>. The sheath <NUM> could be split in concert with its removal from the patient as is illustrated in <FIG>. In certain embodiments, the sheath <NUM> is not splittable.

As noted above, the present access device can be used to place a catheter at other locations within a patient's body. Thus, for example, but without limitation, the access device can be used as or with a variety of catheters to drain fluids from abscesses, to drain air from a pneumotorax, and to access the peritoneal cavity.

Claim 1:
An access device (<NUM>) for placing a medical article within a body space, the access device comprising:
a dilator (<NUM>) comprising:
an elongated dilator body (<NUM>), and
a dilator hub (<NUM>) extending from the elongated dilator body, the dilator hub defining an inner cavity (<NUM>) having a distal cavity portion (<NUM>) and a proximal cavity portion (<NUM>);
characterized in that the access device further comprises;
a valve element (<NUM>) made of a single unitary body having an open position and a closed position, the valve element comprising:
an attachment portion (<NUM>) configured to be supported by the dilator hub, and
a sealing portion (<NUM>) extending radially inwardly from a side of the inner cavity, the sealing portion being biased toward the closed position,
wherein the valve element is configured to inhibit fluid flow between the distal cavity portion and the proximal cavity portion when the valve element is in the closed position, and
wherein the valve element comprises an elastomeric material and/or flexible structure capable of deformation or movement as a guidewire (<NUM>) abuts against and extends through the valve element permitting movement of the guidewire through the dilator hub in a proximal direction relative to the dilator
wherein the sealing portion comprises a first sealing surface (<NUM>),
wherein the dilator hub comprises a second sealing surface (<NUM>), and wherein the first sealing surface is against the second sealing surface to substantially seal the distal cavity portion from the proximal cavity portion when the valve element is in the closed position.