Patent Description:
The present disclosure relates generally to drainage catheters for medical use. More specifically, the present disclosure relates to a looped drainage catheter and methods of exchanging drainage catheters. <CIT> describes barbed fluid connectors for clamping an end of a length of flexible tubing to a fluid fitting. <CIT> describes a device suitable for connection to a substantially tubular element, to a fluid flow indicator, and to a medical drainage device.

The invention is defined by the appended claims with only <FIG> of the drawings showing an embodiment of the coupler according to the invention. The remaining drawings are further embodiments useful for understanding the invention. While various aspects of the embodiments are presented in drawings, the drawings depict only typical embodiments, which will be described with additional specificity and detail through use of the accompanying drawings in which:.

The various embodiments disclosed herein generally relate to, but are not limited to, drainage catheters and related methods of use. More specifically, the various embodiments relate to a drainage catheter that may be used for percutaneous nephrostomy or nephropyelostomy, including providing temporary drainage for an obstructed renal collecting system. In some instances, the obstructed area may become infected, and antibiotics may have limited efficacy reaching the kidney if the obstruction is not drained. Percutaneous nephrostomy may be used to alleviate the obstruction and to create a route for antibiotic instillation and/or other treatments, if needed. As explained in further detail below, in some embodiments, the disclosed drainage catheter may be sufficiently pliable to minimize potential injury during insertion, but also sufficiently rigid to maintain a generally U-shape bend when deployed within the kidney, which may tend to avoid clogging and promote drainage. Also disclosed herein are methods for inserting the drainage catheter into a patient's kidney and methods of exchanging drainage catheters. The specific examples included herein are presented by way of example, the present disclosure may be applied to other catheter applications.

Various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. Many of these features may be used alone and/or in combination with one another.

Embodiments may be understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The components of the present disclosure, as generally described and illustrated in the drawings herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus is not intended to limit the scope of the disclosure, but is merely representative of possible embodiments of the disclosure. In some cases, well-known structures, materials, or operations are not shown or described in detail.

The phrases "connected to," "coupled to," and "in communication with" refer to any form of interaction between two or more entities, including but not limited to mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be coupled to each other even though they are not in direct contact with each other. For example, two components may be coupled to each other through an intermediate component.

The terms "distal" and "proximal" refer to opposite ends of a medical device, including the coupler disclosed herein, as well as the exemplary catheters. As used herein, the distal portion of the catheter is the portion that first enters the patient's body during insertion, while the proximal portion is a portion at the opposite end, along the longitudinal direction of the catheter.

The term "resilient" refers to a component, device, or object having a particular shape that can then be elastically deformed into a different shape, but that may return to the original shape when unconstrained. For example, a resilient portion of the catheter may have a first shape when unconstrained (i.e., when no exterior force acts upon the catheter) and, in use, the resilient portion may then be constrained (i.e., temporarily engaged with a guidewire) to elastically deform the resilient element into a second shape (i.e., a straightened condition over the guidewire). After the catheter is disposed in the kidney, the guidewire may be removed and the catheter may return to its first shape (unconstrained) or substantially to its first shape.

While the written description and figures may reference use of the catheter for percutaneous nephrostomy, the catheter may be used for providing drainage to other organs or anatomical structures, as well as for infusion of medication. Accordingly, the particular uses of the catheter outlined herein are meant as examples and not meant to limit use of the catheter and/or the coupler disclosed herein, to nephrostomy or kidney placement.

<FIG> illustrates an embodiment of a drainage catheter <NUM> that may be used for percutaneous nephrostomy. With general reference to <FIG>, the catheter <NUM> shown in these figures comprises a distal tube segment <NUM> and a proximal tube segment <NUM> connected together via a U-shaped or arcuate end portion <NUM>. The arcuate end portion <NUM> may be generally U-shaped, as shown, or of another shape, as appropriate to the particular application. The catheter <NUM> may include a plurality of drainage holes or openings <NUM> formed along an inner surface <NUM> of the arcuate end portion <NUM>. In some embodiments, the catheter <NUM> is free of drainage holes on an outer surface <NUM> to avoid clogging by surrounding kidney tissues or other structures. In an exemplary operation, once the catheter <NUM> is deployed within a kidney <NUM>, the arcuate end portion <NUM> sits in a renal pelvis <NUM>, with the tube segments <NUM>, <NUM> each disposed outwardly through a skin <NUM> as illustrated in <FIG>. The tube segments <NUM>, <NUM> may be connected to a connector <NUM>, which in turn is connected to a drainage bag or other receptacle (not shown) for collecting the drained material. The connector <NUM> may also include a port for infusing medication into the kidney <NUM> through the catheter <NUM>.

With reference to <FIG>, the catheter <NUM> may comprise a generally elongate, tubular structure that may comprise any of a variety of materials, including resilient and flexible bio-compatible materials, such as silicone rubber, nylon, polyurethane, polyethylene terephthalate (PET), latex, thermoplastic elastomers, or other materials. As mentioned previously, the catheter <NUM> of <FIG> includes a distal tube segment <NUM> and a proximal tube segment <NUM> connected by an arcuate end portion <NUM> to form a continuous structure with a looped or reversing end. A lumen <NUM> may extend through the catheter <NUM> along a central axis <NUM> thereof to provide a passageway for fluids exiting the kidney. In some embodiments, the lumen <NUM> may also be used to introduce antibiotics or other fluids into the kidney as needed, such as to treat infections or to provide other medical relief. In some embodiments, a lead-in portion <NUM> of the distal tube segment <NUM> may be tapered or angled inwardly toward the central axis <NUM>. Further, a lead end <NUM> of the distal tube segment <NUM> may be generally flat, resembling a truncated cone shape, with the lumen <NUM> extending therethrough. Preparatory to disposing the catheter <NUM> in a patient, the catheter <NUM> may be disposed upon a guidewire (see guidewire <NUM> in <FIG>). As is further described below with reference to <FIG>, the lead-in portion <NUM> may be configured to facilitate advancement of the catheter <NUM> along the guidewire <NUM> during insertion into the kidney <NUM>. In other embodiments, the lead-in portion <NUM> may not be tapered.

To facilitate and accurate placement of the catheter <NUM> within the kidney <NUM>, the distal and proximal tube segments <NUM>, <NUM> may each include various depth markers <NUM>, <NUM>, <NUM>, <NUM> printed thereon at predetermined points along the catheter <NUM>. In some embodiments, the depth markers <NUM>, <NUM>, <NUM>, <NUM> encircle the circumference of the respective tube segments <NUM>, <NUM>. For example, with reference to <FIG>, the catheter <NUM> may include a <NUM>-cm band marker <NUM>, a <NUM>-cm band marker <NUM>, a <NUM>-cm band marker <NUM>, and a <NUM>-cm band marker <NUM>, with the respective markers printed on each of the tube segments <NUM>, <NUM>. In the illustrated embodiment, the position of the depth markers <NUM>, <NUM>, <NUM>, <NUM> on the distal tube segment <NUM> mirrors the position of the depth markers <NUM>, <NUM>, <NUM>, <NUM> on the proximal tube segment <NUM>. In other embodiments, markers on each segment <NUM>, <NUM> may not mirror each other. In some embodiments, the marking pattern associated with individual band markers may be unique for each particular depth marker to allow a practitioner to quickly determine the depth from the marking pattern alone rather than having to read a number scale or other numerical indicia. The depth values provided in the above description are for illustration purposes only. In other embodiments, the depth for the depth markers <NUM>, <NUM>, <NUM>, <NUM> may be different from the scale noted above. In addition, the number of depth markers printed on the catheter <NUM> may be more or fewer than the four markers printed on the illustrated embodiment of the catheter <NUM>, in some embodiments, the depth markers <NUM>, <NUM>, <NUM>, <NUM> may include or be replaced by numeric symbols.

With reference to <FIG>, the arcuate end portion <NUM> comprises an inner surface <NUM> and an outer surface <NUM>. The inner surface <NUM> has a first radius of curvature Rinner as measured from a transverse axis <NUM> generally traversing the catheter <NUM> at the edges of the arcuate end portion <NUM>. The outer surface <NUM> has a second radius of curvature Router measured relative to the transverse axis <NUM>, with Router being greater than Rinner.

The inner surface <NUM> of the arcuate end portion <NUM> may comprise a plurality of holes <NUM> formed thereon. The holes <NUM> may extend through the inner surface <NUM> of the catheter <NUM> such that they are in communication with the lumen <NUM>. The holes <NUM> may thus be configured to provide a pathway for waste or other fluids out of the kidney and antibiotics and other medical fluids into the kidney. The holes <NUM> disposed on the inner surface <NUM> of the catheter <NUM> may allow guidewire passage through the catheter <NUM> without the need of fluoroscopy. In some embodiments, the outer surface <NUM> of the catheter <NUM> is free of holes. This absence of holes may be configured to minimize potential blockage and clogging of the holes to maintain patency of the catheter <NUM> as the kidney tissues press against the catheter <NUM>. In other words, the body of the catheter <NUM> may tend to prevent tissue from collapsing against the holes <NUM> disposed along the inner surface <NUM> due to the arcuate shape of the catheter <NUM>, thus helping maintain patency and prevent clogging.

The arcuate end portion <NUM> of the catheter <NUM> may further comprise radiopaque marker bands <NUM>, <NUM>, and <NUM> printed thereon to facilitate placement of the arcuate end portion <NUM> of the catheter <NUM> f. For example, with reference to <FIG>, the catheter <NUM> may include <NUM>-mm wide marker bands <NUM>, <NUM> generally mirroring one another on the tube segments <NUM> and <NUM> and marking the respective ends of the arcuate end portion <NUM>, and include a <NUM>-mm wide marker band <NUM> positioned at a general midpoint of the arcuate end portion <NUM> and along an arc neutral axis <NUM> of the arcuate end portion <NUM> generally perpendicular to the transverse axis <NUM>. In some embodiments, the marker bands <NUM>, <NUM>, and <NUM> may be the same size, for example, <NUM>. In some embodiments, the marker bands <NUM> and <NUM> may be aligned on the transverse axis <NUM>. In such embodiments, the marker band <NUM> may divide the position of the holes <NUM> to ensure an even distribution on the inner surface <NUM> of the catheter <NUM>, with the marker bands <NUM>, and <NUM> bookending the holes <NUM>. In this arrangement, the marker bands <NUM>, <NUM>, and <NUM> collectively provide guidance to determine the position and arrangement of the holes <NUM> during and after insertion of the catheter <NUM>. In addition, the number of marker bands may be more or fewer than the three marker bands <NUM>, <NUM>, and <NUM> on the illustrated embodiment of the catheter <NUM>.

In some embodiments, the catheter <NUM> may include a hydrophilic coating on the catheter surface. The hydrophilic coating may absorb and bind water to promote a smooth and slippery surface and help reduce pain, pressure, or discomfort during the insertion and removal process. With reference to <FIG>, the following sections provide additional details of a process for inserting the catheter <NUM> during a percutaneous nephrostomy procedure according to one exemplary embodiment. Certain steps relating to a percutaneous nephrostomy procedure may not be discussed in detail, however, it is within the scope of this disclosure to use a coupler (see <NUM> in <FIG>) along with a catheter <NUM> to exchange catheters placed according to a variety of procedures.

<FIG> illustrate an exemplary procedure for guiding and placing the catheter <NUM> within a kidney <NUM> during a percutaneous nephrostomy. With reference to <FIG>, a first needle <NUM> housed within a first introducer sheath <NUM> may be used to puncture the skin <NUM> at a first insertion site <NUM>. The needle <NUM> may then be pushed through a first calyx <NUM> to access the renal pelvis <NUM>. With the first needle <NUM> in position, gentle suction may be placed on the first needle <NUM> until urine is aspirated to confirm placement. In some embodiments, the kidney <NUM> may be opacified with contrast to confirm the positioning of the catheter <NUM>. The first needle <NUM> may be retracted from the first introducer sheath <NUM>, and a guidewire <NUM> may be advanced through the first introducer sheath <NUM> and into the renal pelvis <NUM>. In some embodiments, the guidewire <NUM> may include a hydrophilic coating to facilitate movement into the renal pelvis <NUM>. In some embodiments, once the guidewire <NUM> is in position, the first introducer sheath <NUM> may be retracted, leaving the guidewire <NUM> in position. Alternatively, the first introducer sheath <NUM> may be left in position while the guidewire <NUM> is manipulated to couple with a snare <NUM> as described below. In certain embodiments, the first needle <NUM> may be used to puncture the skin <NUM> without the first introducer sheath <NUM> and the guidewire <NUM> may be advanced through the first needle <NUM>.

With particular reference to <FIG>, a second needle <NUM> housed within a second introducer sheath <NUM> may be used to puncture the skin <NUM> at a second insertion site <NUM> and pushed through a second calyx <NUM> toward the renal pelvis <NUM>. The second introducer sheath <NUM> may then be positioned at the renal pelvis <NUM> near the guidewire <NUM>, and the second needle <NUM> may be retracted from the second introducer sheath <NUM>. A second guidewire <NUM> may be inserted through the second introducer sheath <NUM> and advanced toward the guidewire <NUM>. An end of the second guidewire <NUM> may include the snare <NUM> or other grasping device configured to couple, to a portion of the guidewire <NUM> such as via a curved tip end <NUM>. In embodiments where the guidewire <NUM> does not include the curved tip end <NUM> (e.g., the guidewire <NUM> may instead have a planar end), the snare <NUM> may be used to ensnare an end portion of the guidewire <NUM>. Once the snare <NUM> is coupled to the guidewire <NUM>, the second guidewire <NUM> may be retracted to advance the guidewire <NUM> such that the guidewire <NUM> extends from the first calyx <NUM> to the renal pelvis <NUM> and out the second calyx <NUM>.

As generally illustrated in <FIG>, the catheter <NUM> may then be inserted into the kidney <NUM>. With the guidewire <NUM> in position, the catheter <NUM> may first be straightened out to generally flatten out the arcuate end portion <NUM> for insertion. The lead-in portion <NUM> may be inserted onto the guidewire <NUM> and advanced along the guidewire <NUM> into the first calyx <NUM>, through the renal pelvis <NUM>, and out the second calyx <NUM>. The catheter <NUM> may then be pulled outwardly through the second insertion site <NUM> until the arcuate end portion <NUM> is resting in a desired position within the renal pelvis <NUM>. The radiopaque marker bands <NUM>, <NUM>, <NUM> may be used to position the holes <NUM>. In some embodiments, a dilator (not shown) may be advanced over the guidewire <NUM> prior to insertion of the catheter <NUM> to further guide the catheter <NUM>.

As noted previously, the arcuate end portion <NUM> may be resilient such that the arcuate end portion <NUM> rends to return to its initial curved configuration once the catheter <NUM> is free from external forces (see <FIG>). The curvature of the arcuate end portion <NUM> and the placement of the holes <NUM> along the inner surface <NUM> may avoid clogging of the catheter <NUM> and promote drainage of the kidney <NUM> through the lumen <NUM>.

With reference to <FIG>, once the catheter <NUM> is positioned within the kidney <NUM>, the first introducer sheath <NUM> and the second introducer sheath <NUM> may be removed. In addition, once the catheter <NUM> is positioned within the kidney <NUM>, one or both of the tube segments <NUM> and <NUM> may be cut to a desired length to manage the catheter <NUM> as needed. For example, in one embodiment, the lead-in portion <NUM> of the distal tube segment <NUM> may be cut off and a connector <NUM> may be attached to both the distal and proximal tube segments <NUM> and <NUM> to direct fluids removed from the kidney <NUM> to a drainage bag or other receptacle (not shown). In some embodiments, the connecter <NUM> may include a port for the introduction of antibiotics or other medicine for infusion to the kidney <NUM>. Further, the connector <NUM> may include a break-away portion that is removable to avoid damage that may be caused to the kidney <NUM> or other surrounding structures by accidental pulling or removal of the catheter <NUM>. In some embodiments, the connector <NUM> may include break-away features such as those described in <CIT> and<CIT>.

In some embodiments, a pigtail nephrostomy catheter may be inserted into a kidney <NUM> of the patient through the first calyx <NUM> to access the renal pelvis <NUM>. The pigtail nephrostomy catheter may not need dual access to the kidney <NUM> like the drainage catheter <NUM> and therefore the pigtail catheter may not exit the kidney <NUM> through the second calyx <NUM>. The pigtail nephrostomy catheter may be inserted for a short-term nephrostomy, however, if a longer-term nephrostomy catheter is needed, the pigtail catheter may be replaced using a long-term nephrostomy catheter, such as the drainage catheter <NUM>. If the pigtail catheter is replaced, the drainage catheter <NUM> may pass through the pre-existing tract into the kidney <NUM> made by the pigtail catheter and a fresh tract may be created to access the second calyx <NUM> so that the drainage catheter <NUM> may exit the patient.

Once disposed, over time the catheter <NUM> may become unsuitable to the purpose of emplacement. For example, the holes <NUM> or the lumen <NUM> may become blocked, or the patient may respond adversely to the material of which the catheter <NUM> is manufactured, or another medical treatment may require replacement of the particular catheter <NUM> with a different catheter. Rather than withdraw the catheter <NUM> and repeat the initial emplacement procedure with a new catheter, in some procedures a coupler (such as <NUM> of <FIG>) may facilitate replacing the catheter <NUM>.

<FIG> is a perspective view of a coupler <NUM> having a body <NUM>, two ends <NUM>, <NUM> and a lumen <NUM>. The lumen <NUM> extends from the first end <NUM> through the body <NUM> to the second end <NUM> and may be centrally disposed within the coupler <NUM>. In some embodiments, the coupler <NUM> may be solid and not have a lumen. The coupler <NUM> includes a first barb <NUM> at the first end <NUM> and a second barb <NUM> at the second end <NUM>. Each barb <NUM>, <NUM> has a tapering profile with a first diameter D<NUM> narrower than a second diameter D<NUM>. The first barb <NUM> has the first diameter D<NUM> disposed toward the first end <NUM> of the coupler <NUM>. The second barb <NUM> has the first diameter D<NUM> disposed toward the second end <NUM> of the coupler <NUM>. In other words, the two barbs <NUM>, <NUM> taper toward their respective ends <NUM>, <NUM> where each barb <NUM>, <NUM> is disposed.

The coupler <NUM> may be configured to couple to a catheter by inserting a portion of the coupler <NUM> into a lumen of the catheter. For instance, the first diameter D<NUM> of each barb <NUM>, <NUM> may be sized smaller than a diameter of a lumen of a catheter to which the coupler <NUM> is configured to be coupled. The second diameter D<NUM> may be larger than a diameter of a lumen of the catheter. For example, with reference to the catheter of <FIG>, in some embodiments, the first diameter D<NUM> of the first barb <NUM> is small enough to fit into the lumen <NUM> of the catheter <NUM>, while the second diameter D<NUM> of the first barb <NUM> is large enough to at least minimally resist being inserted into the lumen <NUM> of the catheter <NUM>. The material from which the catheter <NUM> is manufactured may be sufficiently flexible to expand over the first barb <NUM> to permit insertion of the first barb <NUM> into the lumen <NUM>, and also sufficiently resilient that the portion of the catheter <NUM> which extends past the first barb <NUM> of the coupler <NUM> may tend to compress inward around the body <NUM> of the coupler <NUM>. Along with the shape of the first barb <NUM>, the compression of the catheter <NUM> may sufficiently resist tension to decouple the catheter <NUM> from the first barb <NUM> when the tension is applied to the coupled coupler <NUM> and catheter <NUM>. The second barb <NUM> may be inserted into a replacement catheter (<NUM>' of <FIG>) in a similar fashion. When thus coupled and with reference to catheters <NUM>, <NUM>' of <FIG>, the coupler <NUM> may resist decoupling from the catheter <NUM> and the replacement catheter <NUM>' to permit the catheter <NUM> to be drawn out of the body and the replacement catheter <NUM>' is drawn into the body. The coupler <NUM> may provide sufficient tensile strength to avoid parting (breakage of the coupler <NUM> or decoupling from either catheter <NUM>, <NUM>') during the catheter replacement procedure. Emplacing the replacement catheter <NUM>' by coupling it to the catheter <NUM> via the coupler <NUM> may be used instead of the potentially more invasive emplacement procedure used to initially place the catheter <NUM>. In some embodiments, the coupler <NUM> may include one or more radiopaque markers (not shown) to facilitate emplacement.

<FIG> depicts an embodiment of a coupler <NUM> that resembles the coupler <NUM> described above in certain respects. Accordingly, like features are designated with like reference numerals, with the leading digit incremented to "<NUM>. " For example, the embodiment depicted in <FIG> includes first barb <NUM> that may, in some respects, resemble the first barb <NUM> of <FIG>. Relevant disclosure set forth above regarding similarly identified features thus may not be repeated hereafter. Moreover, specific features of the coupler <NUM> and related components shown in <FIG> may not be shown or identified by a reference numeral in the drawings or specifically discussed in the written description that follows. However, such features may clearly be the same, or substantially the same, as features depicted in other embodiments and/or described with respect to such embodiments. Accordingly, the relevant description of such features apply equally to the features of the coupler <NUM> and related components depicted in <FIG>. Any suitable combination of the features, and variations of the same, described with respect to the coupler <NUM> and related components illustrated in <FIG>, can be employed with the coupler <NUM> and related components of <FIG>, and vice versa. This pattern of disclosure applies equally to further embodiments depicted in subsequent figures and described hereafter, wherein the leading digits may be further incremented.

<FIG> is a perspective view of an embodiment of a coupler <NUM> similar to the coupler <NUM> of <FIG> and having a flange <NUM>. A lumen <NUM>, a first barb <NUM>, and a second barb <NUM> are shown for reference. The flange <NUM> is disposed at or near a longitudinal midpoint of a body <NUM>. In other words, in the illustrated embodiment, the flange <NUM> is approximately midway between the first barb <NUM> and the second barb <NUM>. In the embodiment of <FIG>, the flange <NUM> circumscribes the body <NUM>. The flange <NUM> has a diameter D<NUM> approximately equal to the second diameter D<NUM> of either barb <NUM>, <NUM>. In another embodiment, the diameter D<NUM> of the flange <NUM> may exceed the second diameter D<NUM> of the barbs <NUM>, <NUM>. In an embodiment of the coupler <NUM> intended to replace the catheter <NUM> of one diameter with the replacement catheter <NUM>' having a different diameter, the barbs <NUM>, <NUM> may each have a diameter D<NUM> corresponding to the catheter <NUM>, <NUM>' to which each may be coupled. In such an embodiment, the flange <NUM> may include a taper to "step up" or "step down" from one catheter size to another catheter size. In some embodiments, the flange <NUM> may comprise a radiopaque marker.

<FIG> is a perspective view of an embodiment of a coupler <NUM> similar in some respects to the coupler <NUM> and the coupler <NUM> of <FIG>, respectively, having a plurality of barbs <NUM>, <NUM>, <NUM>, <NUM> disposed toward either end <NUM>, <NUM>. The barbs <NUM>, <NUM>, <NUM>, <NUM> disposed at the first and second ends <NUM>, <NUM> and a lumen <NUM> are shown for reference. A first distal barb <NUM> may be disposed at or near the first end <NUM> of the coupler <NUM>, and a first proximal barb <NUM> may be disposed somewhat proximally relative to the first distal barb <NUM>. A first untapered region <NUM> may be disposed between the first distal barb <NUM> and the first proximal barb <NUM>. Similarly, a second distal barb <NUM> may be disposed at or near the second end <NUM> of the coupler <NUM>, with a second proximal barb <NUM> disposed somewhat proximally relative to the second distal barb <NUM>, and a second untapered region <NUM> may be disposed between the second distal and second proximal barbs <NUM>, <NUM>. The additional barbs <NUM>, <NUM> further engage with the catheter <NUM>, <NUM>' to help secure the coupler <NUM> to the catheters <NUM>, <NUM>'. In at least one embodiment, the coupler <NUM> may include a flange <NUM>.

<FIG> is a perspective view of an embodiment of a coupler <NUM> similar to the coupler <NUM> of <FIG> in certain respects and having a plurality of flex slots <NUM> in a central body portion <NUM>. The flex slots <NUM> may extend along a portion of the circumference of the central body portion <NUM>. First distal and proximal barbs <NUM>, <NUM>, second distal and proximal barbs <NUM>, <NUM> and a lumen <NUM> are shown for reference. The central body portion <NUM> may comprise a plurality of the flex slots <NUM> to permit the coupler <NUM> to flex about the central body portion <NUM> while minimizing the risk of unintended deformation of the coupler <NUM>. The flexibility of the central body portion <NUM> enables the coupler <NUM> to bend while the catheters <NUM>, <NUM>' are disposed within the patient. For example, as discussed in more detail below, the coupler <NUM> couples the catheter <NUM>' and the replacement catheter <NUM>' and as the catheter <NUM> is drawn out of the patient and the replacement catheter is drawn into the patient, the flexibility of the central body portion <NUM> help enable the coupler <NUM> navigate corners within the patient, e.g., the renal pelvis in the patient's kidney. The flexibility of the central body portion <NUM> has helps the coupler <NUM> maintain continuity between the catheters <NUM>, <NUM>' and minimize the possibility of the coupler <NUM> disconnecting from one of the catheters <NUM>, <NUM>' during the procedure. In at least one embodiment, a flange <NUM> may be disposed at the central body portion <NUM>.

<FIG> is a perspective view of an embodiment of a coupler <NUM> similar in some respects to the coupler <NUM> of <FIG>. First distal and proximal barbs <NUM>, <NUM>, second distal and proximal barbs <NUM>, <NUM> and a lumen are shown for reference. The coupler <NUM> may have a flex coil <NUM> disposed in a central body portion <NUM> of the coupler <NUM>. The flex coil <NUM> may permit the coupler <NUM> to flex about the central body portion <NUM> of the coupler <NUM> while minimizing the risk of unintended deformation of the coupler <NUM>. The flexibility of the central body portion <NUM> enables the coupler <NUM> to bend while the catheters <NUM>, <NUM>' are disposed within the patient. For example, as discussed in more detail below, the coupler <NUM> couples the catheter <NUM>' and the replacement catheter <NUM>' and as the catheter <NUM> is drawn out of the patient and the replacement catheter is drawn into the patient, the flexibility of the central body portion <NUM> help enable the coupler <NUM> navigate corners within the patient, e.g., the renal pelvis in the patient's kidney. The flexibility of the central body portion <NUM> has helps the coupler <NUM> maintain continuity between the catheters <NUM>, <NUM>' and minimize the possibility of the coupler <NUM> disconnecting from one of the catheters <NUM>, <NUM>' during the procedure.

<FIG> illustrate of an example of a procedure where a first catheter, such as catheter <NUM> has been disposed in the kidney <NUM> and the catheter <NUM> is to be replaced by a second catheter, such as replacement catheter <NUM>'. The first catheter may be similar to the drainage catheter <NUM> or may be a pigtail drainage catheter. The first catheter and the second catheter may or may not include lead-in portions, similar to the lead-in portions <NUM> of catheter <NUM> described in <FIG>. <FIG> illustrates catheter <NUM> coupled to replacement catheter <NUM>' by the coupler <NUM> of <FIG>, which is used as example, but it is within the scope of the disclosure to use any of the couplers described herein. <FIG> is an illustration showing a partially completed replacement of the catheter <NUM>. With respect to <FIG>, a kidney emplacement is shown; however, other catheter replacement scenarios in other parts of the body are within the scope of this disclosure. The catheter <NUM> may have been emplaced as described in connection with <FIG> or a pigtail catheter may be emplaced. Prior to replacement, the catheter <NUM> may be cut or otherwise detached from any accoutrement external to the patient, such as the connector <NUM>.

The coupler <NUM> may be used to facilitate replacement of the catheter <NUM> with the replacement catheter <NUM>'. The coupler <NUM> may be coupled to the proximal tube segment <NUM> of the catheter <NUM> by inserting the first barb <NUM> of the coupler <NUM> in the lumen <NUM> of the proximal tube segment <NUM> of the catheter <NUM>. The second barb <NUM> of the coupler <NUM> may be inserted into a lumen <NUM>' of a distal tube segment <NUM>' of the replacement catheter <NUM>'. In some embodiments, if the distal tube segment <NUM>' of the replacement catheter <NUM>' includes a tapered lead-in portion, the lead-in portion may be removed (cut off) before inserting the coupler <NUM> into the lumen <NUM>'. The coupler <NUM> may be coupled to either the catheter <NUM> or the replacement catheter <NUM>' first, then coupled to the other catheters <NUM>, <NUM>'.

A guidewire <NUM>' may be inserted into the lumens <NUM>, <NUM>', <NUM> of the catheters <NUM>, <NUM>' and the coupler <NUM>. With the distal tube segment <NUM>' of the replacement catheter <NUM>' coupled via the coupler <NUM> to the proximal tube segment <NUM> of the catheter <NUM>, the distal tube segment <NUM> of the catheter <NUM> may be drawn out of the patient. As the catheter <NUM> is drawn out of the patient, the replacement catheter <NUM>' is pulled through the first insertion site <NUM>, through the renal pelvis <NUM>, and through the second insertion site <NUM>. Radiopaque marker bands <NUM>', <NUM>', <NUM>' disposed at an arcuate end portion <NUM>' of the replacement catheter <NUM>' may facilitate placement of the arcuate end portion <NUM>' in the renal pelvis <NUM>. In <FIG>, the replacement process is illustrated with the coupler <NUM> in the renal pelvis <NUM>. While the coupler <NUM> is shown with no flex, in at least some embodiments, the coupler <NUM> may be of a type that may flex as the coupler <NUM> passes through the renal pelvis <NUM> or around other paths.

<FIG> is an illustration of the replacement catheter <NUM>' having been fully drawn into place utilizing the coupler <NUM> following pre-existing pathways created by the placement of the first catheter. In an example where a pigtail catheter is used and only there is only an existing pathway into the kidney <NUM> and not out of the kidney <NUM>, a similar method may be used to create a pathway for the replacement catheter <NUM>' to exit the kidney. The coupler <NUM> may be detached from the distal tube segment <NUM>' of the replacement catheter <NUM>' by cutting the distal tube segment <NUM>' near the coupler <NUM> with an appropriate tool. The coupler <NUM> may remain coupled to the proximal tube segment <NUM> of the catheter <NUM> for ease of disposal and to prevent risk of losing the coupler <NUM> (such as the fully detached coupler falling to the floor or into the patient's bedding or clothing). Either before or after detaching the coupler <NUM> from the replacement catheter <NUM>', the radiopaque marker bands <NUM>', <NUM>', <NUM>' associated with the arcuate end portion <NUM>' of the replacement catheter <NUM>', as well as depth markers <NUM>', <NUM>', <NUM>', <NUM>' along a proximal tube segment <NUM>' and the distal tube segment <NUM>' may be used to confirm the position of the replacement catheter <NUM>' such that the arcuate end portion <NUM>' is disposed in the renal pelvis <NUM>.

<FIG> is an illustration of the replacement catheter <NUM>' having been disposed utilizing the coupler <NUM> and prepared for coupling to an external connector <NUM>' external to the skin <NUM>. The connecter <NUM>' may be first coupled to the distal tube segment <NUM>' after the coupler <NUM> has been detached, and then coupled to the proximal tube segment <NUM>', as shown. Alternatively, the connector <NUM>' may be coupled first to the proximal tube segment <NUM>' and then to the distal tube segment <NUM>'. The tube segments <NUM>', <NUM>' may be connected to the connector <NUM>', which in turn is connected to a drainage bag or other receptacle/medical service device (not shown) for collecting the drained material.

<FIG> illustrates a coupler delivery system <NUM> according to an embodiment of the present disclosure. The coupler delivery system <NUM> may include a coupler handle <NUM> and a coupler <NUM>. The coupler handle <NUM> may be a clamp-grip. The coupler <NUM> may be a coupler of any type disclosed herein. The first distal and proximal barbs <NUM>, <NUM> and the second distal and proximal barbs <NUM>, <NUM> of the coupler <NUM> are shown. The coupler <NUM> may include a flange <NUM>. The coupler handle <NUM> may be manufactured of any suitable material compatible with the coupler <NUM>. The coupler handle <NUM> may be formed as a single-piece tool, for example, by press molding, injection molding, or any other appropriate method. In another embodiment, the coupler handle <NUM> may be formed as a multi-piece tool wherein each component may be of any appropriate material and then assembled to form the coupler handle <NUM>.

In the illustrated embodiments, the coupler handle <NUM> comprises a first handle <NUM>, a second handle <NUM>, a torsion spring <NUM>, a first clamp jaw <NUM>, a second clamp jaw <NUM>, and a backstop <NUM>. The first and second handles <NUM>, <NUM> may be held in a spread configuration by the torsion spring <NUM>. The torsion spring <NUM> may also press the first clamp jaw <NUM> and the second clamp jaw <NUM> toward or against each other. The coupler <NUM> may be seated between the first and second clamp jaws <NUM>, <NUM> such that the coupler <NUM> buts against the backstop <NUM>. The flange <NUM> may serve to prevent the coupler <NUM> from moving rearward toward the torsion spring <NUM> as pressure may be applied to couple the coupler <NUM> to the catheter <NUM>, <NUM>'. The backstop <NUM> may be configured with a pin (not shown) that may protrude into the lumen of the coupler <NUM>. The backstop <NUM> may be configured with a recessed ring (not shown) in the face of the backstop <NUM> proximal to the first and second clamp jaws <NUM>, <NUM>. The pin and/or recessed ring may assist in keeping the coupler <NUM> stable as pressure is applied to couple the coupler <NUM> to the catheter <NUM>, <NUM>'.

In some embodiments, the coupler <NUM> does not have a backstop to prevent axial movement. Axial movement in this embodiment may be limited by the flange <NUM> and the barb <NUM> when the flange <NUM> or the barb <NUM> engage with the first and second clamp jaws <NUM>, <NUM>.

The first and second handles <NUM>, <NUM> may be pressed toward each other in opposing directions FA, FA', which may simultaneously cause the first and second clamp jaws <NUM>, <NUM> to move in opposing directions FB, FB' and thereby release the coupler <NUM> from the coupler handle <NUM>. The coupler delivery system <NUM> may be provided fully assembled having the coupler <NUM> pre-coupled to the clamp-grip <NUM> from a manufacturer. In another embodiment, the coupler <NUM> may be coupled to the coupler handle <NUM> immediately prior to and preparatory to coupling the coupler <NUM> to the catheter <NUM>, <NUM>'.

<FIG> is an exploded perspective view of a coupler delivery system <NUM>, according to another embodiment, including a coupler <NUM> and a coupler handle <NUM>. As with the embodiment of <FIG>, the coupler <NUM> may be of any type disclosed herein. <FIG> is an assembled perspective view of the coupler delivery system <NUM> of <FIG>. With respect to <FIG>, the first distal and proximal barbs <NUM>, <NUM>, the second distal and proximal barbs <NUM>, <NUM> are shown for reference. The coupler <NUM> may include the flange <NUM>. The coupler handle <NUM> may further include a plurality of ribs <NUM> and voids <NUM>.

The coupler handle <NUM> may a snap fitting <NUM> to secure the coupler <NUM> to the coupler delivery system <NUM>. The snap fitting <NUM> comprises a plurality of arms <NUM>, with each arm <NUM> having a lug <NUM>. The lug <NUM> of each arm <NUM> may be configured to snap over the first distal barb <NUM> of the coupler <NUM> so as to couple the coupler <NUM> to the coupler handle <NUM>. The snap fitting <NUM> may be sufficiently resilient to retain the coupler <NUM> on the coupler handle <NUM> against the application of lateral forces, and may also be sufficiently flexible to allow the snap fitting <NUM> to release the coupler <NUM> from the coupler handle <NUM> at the application of a predetermined lateral force. In other words, the amount of force to disengage the coupler handle <NUM> from the coupler <NUM> is less than the amount of force to remove the coupler <NUM> from the lumen of one of the catheters <NUM>, <NUM>'. The medical care giver may also squeeze the distal tube segment <NUM>, <NUM>' of the catheter <NUM>, <NUM>' where the catheter <NUM>, <NUM>' is coupled to the coupler <NUM> to ensure the catheter <NUM>, <NUM>' and the coupler <NUM> remain coupled together as lateral force is applied to the coupler handle <NUM> to release the coupler <NUM> from the coupler handle <NUM>.

The coupler handle <NUM> may include a stabilizing pin <NUM> which fits into the lumen of the coupler <NUM> to provide stability while the coupler <NUM> is being coupled to the catheter <NUM>, <NUM>'. The coupler handle <NUM> may be manufactured of any material suitable to the coupling <NUM>.

As noted above, the coupler handle <NUM> may include a plurality of the ribs <NUM> and the voids <NUM> to provide a gripping surface for the medical care giver. The gripping surface may be beneficial for medical care givers if their hands are wet or if the gloves they are wearing are wet. The coupler <NUM> may be coupled to the coupler handle <NUM> during manufacture. In another embodiment, the coupler <NUM> may be fitted to the coupler handle <NUM> immediately prior to and in preparation of the catheter replacement procedure.

<FIG> is a perspective view of a coupler delivery system <NUM> similar in some respects to the coupler delivery system <NUM> of <FIG>. The coupler delivery system <NUM> may comprise a coupler handle <NUM> having a well <NUM>. The coupler handle <NUM> may include a plurality of ribs <NUM> and voids <NUM> to provide a gripping surface for the medical care provider. The well <NUM> of the coupler handle <NUM> may be configured to receive and hold the coupler <NUM> to facilitate coupling the coupler <NUM> to the catheter <NUM>, <NUM>'. <FIG> shows cross-sectional plane 17B-17B for <FIG>.

<FIG> is a cross-sectional side view of the coupler delivery system <NUM> of <FIG>. The first distal barb <NUM> and the lumen <NUM> of the coupler <NUM> are shown for reference. The well <NUM> of the coupler handle <NUM> may include one or more lugs <NUM>. The lugs <NUM> may be configured to snap over the first distal barb <NUM> of the coupler <NUM> so as to couple the coupler <NUM> to the coupler handle <NUM>. The lugs <NUM> may be configured to retain the coupler <NUM> under lateral forces, and to permit the coupler <NUM> to decouple from the coupler handle <NUM> with the application of a predetermined lateral force. In other words, the amount of force to disengage the coupler handle <NUM> from the coupler <NUM> is less than the amount of force to remove the coupler <NUM> from the lumen of one of the catheters <NUM>, <NUM>'. The well <NUM> of the coupler handle <NUM> may include an inner wall <NUM> having a taper to accommodate flexing of the coupler <NUM> as lateral force is applied to decouple the coupler <NUM> once the coupler <NUM> has been coupled to the catheter <NUM>, <NUM>'.

<FIG> is a perspective view of a coupler delivery system <NUM> similar to the coupler delivery system <NUM> of <FIG> in some respects. The coupler handle <NUM> may have ribs <NUM> and voids <NUM> as previously described. The coupler handle <NUM> may also include an annular ring <NUM> and a well <NUM>, both disposed at an end of the coupler handle <NUM>. The well <NUM> may be a centrally disposed feature of the annular ring <NUM>. In other words, the annular ring <NUM> may be located at one end of the coupler handle <NUM>, and may have an opening (the well <NUM>). As with the coupler delivery system <NUM> of <FIG>, a coupler (not shown) of any type disclosed herein may be coupled to the coupler handle <NUM>, such as by fitting into the well <NUM> of the annular ring <NUM>. <FIG> shows cross-sectional plane 18B-18B for <FIG>.

<FIG> is a side cross-sectional view of the coupler delivery system <NUM> of <FIG>. The well <NUM> of the annular ring <NUM> may have a tapered inner wall <NUM>. One or more lugs <NUM> may be disposed at the inner wall <NUM>. The well <NUM> may include a stabilizing pin <NUM>.

<FIG> is side view of a coupler delivery system <NUM> having a coupler <NUM> pre-coupled to the replacement catheter <NUM>'. The coupler <NUM> may be a coupler of any type disclosed herein. The coupler <NUM> may be coupled to the proximal tube segment <NUM>' of the replacement catheter <NUM>' at the time of manufacture, or at a time prior to packaging for delivery into a health care system. The coupler <NUM> may include the flange <NUM>. When replacing an emplaced catheter <NUM> (see <FIG>), a health care giver may couple the exposed portion of the coupler <NUM> to the proximal tube segment <NUM> of the catheter <NUM>. The guidewire <NUM>' may be inserted, and the replacement catheter <NUM>' may proceed as outlined above. Once the replacement catheter <NUM>' is emplaced, the proximal tube segment <NUM> of the catheter <NUM> may be cut to detach the coupler <NUM> and the catheter <NUM> from the emplaced replacement catheter <NUM>'.

A coupler delivery system according to any of the embodiments of this disclosure may be delivered to a medical care facility in the form of a sealed and sterile kit (not shown). By way of example without limitation, the kit may include the coupler delivery system, a guidewire, site preparation materials (such as, e.g., a cleaning swab), a shear, disposal materials, etc. The kit may include a replacement catheter (the coupler delivery system <NUM> includes a catheter as a component of the coupler delivery system <NUM>). The kit may also include a connector. The kit may also include further components which may couple to the connector for a particular purpose. A kit may be provided with a coupler delivery system and additional components as may be specially ordered by the health care system.

References to approximations are made throughout this specification, such as by use of the term "substantially. " For each such reference, it is to be understood that, in some embodiments, the value, feature, or characteristic may be specified without approximation. For example, where qualifiers such as "about" and "substantially" are used, these terms include within their scope the qualified words in the absence of their qualifiers. For example, where the term "substantially straight" is recited with respect to a feature, it is understood that in further embodiments, the feature can have a precisely straight configuration.

Similarly, the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any claim requires more features than those expressly recited in that claim. Rather, as the following claims reflect, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment.

The claims following this written disclosure are hereby expressly incorporated into the present written disclosure, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. Moreover, additional embodiments capable of derivation from the independent and dependent claims that follow are also expressly incorporated into the present written description.

Claim 1:
A catheter exchange system, comprising:
a second catheter (<NUM>') comprising:
a tubular body having a first end and a second end; and
a lumen extending from the first end of the tubular body to the second end of the tubular body; and
a coupler (<NUM>) comprising:
a body having a first end and a second end; and
at least one barb disposed at the first end of the coupler and at least one barb disposed at the second end of the coupler,
wherein the coupler is configured to couple to a first catheter (<NUM>) and the second catheter (<NUM>') by coupling the first end of the coupler to the first catheter and coupling the second end of the coupler to the second catheter, wherein the coupler is configured to use during a catheter replacement procedure to replace the first catheter (<NUM>) with the second catheter (<NUM>') when the first catheter is disposed within a patient,
wherein the coupler has a central body portion (<NUM>) that is disposed between the at least one barb disposed on the first end and the at least one barb disposed on the second end, wherein the central body portion is flexible and allows the central body portion to bend, and wherein the central body portion includes a plurality of flex slots (<NUM>) disposed in the body of the coupler that partially extend circumferentially around the central body portion.