Catheters are routinely used to form a semi-permanent path into the body for allowing the drainage of fluids from sites of infection, trauma, or abscess or fluids such as urine which are produced through normal metabolic function. Pigtail catheters are a common type of these drainage catheters, with a distal portion that curls like a pig's tail to maintain the catheter in the desired location.
Pigtail catheters are maintained straight during insertion, and upon deployment are curled into an annular shape. These catheters are especially useful for the drainage of abscesses or of the urinary bladder. The pigtail construction promotes retention of the catheter in the target location (e.g., within the bladder) as the size of the curled distal tip extends across the opening of the vessel through which the catheter was inserted into the location. The distal tips of conventional pigtail catheters are looped by pulling a string or suture extending from the distal tip along the catheter to a manual control at the proximal end and the catheter is then connected to another device (e.g., a collection bag, additional tubing) using, for example, a pair of locking hubs.
In one aspect, the present invention is directed to a catheter comprising an elongated body extending from a flexible distal portion to a proximal portion and including a fluid transport lumen extending therethrough and a tensioning member lock collar slidably coupled to the proximal portion for movement relative thereto, the tensioning member lock collar including a connection for coupling the proximal portion of the catheter to a fluid receiving structure in combination with a tensioning member coupled between the flexible distal portion and the tensioning member lock collar so that movement of the tensioning member lock collar proximally along the elongated body draws the tensioning member proximally a first distance and curls the flexible distal portion by a first amount.
The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The invention relates generally to catheters and more particularly to catheters for draining fluids from the body.
The present invention provides a pigtail catheter deployable by applying tension to a suture that is largely internal to the catheter during and after deployment, reducing the risk of infection and of degradation of the suture material over time, as well as reducing chances of leakage. The embodiments of the present invention also provide for a pigtail catheter in which the distal end is automatically curled into a desired pigtail shape as the catheter is joined to another device without requiring the user to perform any additional act. The distance through which the suture is pulled can be further adjusted according to embodiments of the invention, so that the pigtail loop is tightened to a desired degree.
As shown in
The exemplary catheter 100 comprises a flexible, elongated body 106 terminating at a distal pigtail portion 102 which is biased toward a desired curled shape by, for example, heat setting. The elongate body 106 is generally kept substantially straight during insertion into the site to be drained by, for example, a stiffening member inserted therein. A suture 108 is attached internally near a distal tip 118 of the distal pigtail portion 102 and runs along a lumen 101 extending through the catheter 100 substantially the length of the elongated body 106, to an opening 103 formed in a proximal end of the catheter 100. A plurality of holes 104 are formed through the wall of the distal pigtail portion 102 to fluidly couple the lumen 101 to the external environment so that fluids to be drained fluid from the area surrounding the distal pigtail portion 102 enter the lumen 101 and pass to a separate fluid conduit or reservoir (not shown) attached to the proximal end of the catheter 100. As would be understood by those skilled in the art, the holes 104 may be distributed along any portion of the length of the elongated body 106 to tailor the catheter 100 to any specific application but will generally be distributed along only that portion of the length of the elongated body 106 which, when the catheter 100 is in a desired position within the body, is located within the area to be drained.
A first suture lock collar 112 is slidably received around the proximal portion of the exemplary catheter for movement between a distal, de-coupled position and a proximal, coupled position in which the first suture lock collar 112 may be engaged with a corresponding second lock collar 114 of a mating separate device. This connection is used to fluidly couple the lumen 101 to a corresponding lumen in the separate device. The suture 108 extends through the lumen 101 to an exit orifice 111 through which the suture 108 penetrates the wall of the catheter 100 to couple to the first suture lock collar 112. The exit orifice is preferably located on a portion of the catheter 100 which, when the first suture lock collar 112 is in the distal, de-coupled position, is covered by the first suture lock collar 112. This portion of the catheter 100 is designed to remain outside the body when the distal pigtail portion 102 is in a desired position within the body. Moving the first suture lock collar 112 proximally from the de-coupled position to the coupled position to connect the catheter 100 to the separate device draws the suture 108 proximally, pulling the distal pigtail portion 102 into the desired curved, pigtail shape.
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In addition,
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A flexible, strain relief section 110 or sheath may also be provided around the proximal portion of the catheter 100 to form a seal around the exposed portion of the suture 108 to prevent fluid leakage from the orifice 111 from contaminating the surfaces of the catheter 100 which are handled by health care professionals, etc. The flexible, strain relief section 110 may, for example, be formed as a shell-like structure a distal end of which creates a fluid tight seal around a portion of the elongated body 106 immediately distal to a distal end of the first suture lock collar 112 when the first suture lock collar 112 is in the de-coupled position.
A proximal end of the strain relief section 110 is preferably coupled to the distal end of the first suture lock collar 112 so that, as the first suture lock collar 112 is moved proximally to the coupled position, the strain relief section 110 is drawn proximally to cover the exposed portion of the suture 108 while maintaining a seal around the entire area exposed to the suture 108 and any fluids that may leak from the exit orifice 111. Thus, drawing the first suture lock collar 112 proximally to couple the catheter 100 to a separate device draws the distal pigtail portion 102 into the desired curved, pigtail shape and pulls the strain relief section 110 proximally to ensure that the suture 108 is completely internal to the catheter 100 and is not exposed to the outside environment.
As shown in the enlargements of
The use of the catheter 100 is described below with reference to
As described above, this proximal motion of the first suture lock collar 112 applies tension to an actuation member and the suture 108, which in turn pulls the distal tip 118 inward and curls the distal pigtail portion 102 to form the pigtail shape within the larger hollow organ. The curled distal pigtail portion 102 then provides a check to removal of the catheter 100 from the large organ as a diameter of the curled shape of the distal pigtail portion 102 is preferably selected to be larger than that of the vessel via which the catheter 100 was inserted into the organ. Thus, no separate action needs to be performed to secure the catheter 100 in place, as the pigtail shape is formed automatically when the first suture lock collar 112 is connected to the second lock collar 114. Then, when the first suture lock collar 112 has been connected to the second lock collar 114, it is no longer able to move distally in the direction of the arrow A and the tension remains on the suture 108 which effectively locks the distal pigtail portion 102 in the curled, pigtail shape preventing unintentional removal of the catheter 100 from the desired location.
In many applications it is desirable to control the shape of the pigtail formed at the distal end of the catheter when the suture is pulled proximally during connection of the suture lock collar to the second lock collar. For example, as shown in
The embodiments of the present invention provide to the user a system to select an amount of curling, or curvature of a distal flexible portion of a catheter after a suture lock collar thereof has been moved proximally to connect with the luer. The shape of the flexible distal portion after movement of the suture lock collar, referred to as the first loop configuration, may be a minimally curved loop. In one exemplary embodiment, an adjusting mechanism is provided that lets the user select an additional distance through which the suture collar 136 is pulled after a given movement (called the throw) of the first suture lock collar 112. In this case, the throw of the mechanism can be reduced, since it is not exclusively responsible for drawing the suture proximally. Those skilled in the art will understand that the adjusting mechanism may be formed as a part of the first suture lock collar 112. Alternatively, the adjusting mechanism may replace the suture collar 136.
According to the present invention, the draw applied to the suture does not have to be directly coupled to the throw of the suture lock collar. Instead, tension may be applied to the suture entirely by the adjusting mechanism, or by a combination of the translation of the suture lock collar and the adjusting mechanism. In the exemplary embodiment shown in
According to an exemplary embodiment of the invention, the suture ring 220 may be rotated by engaging a thumb wheel 212 coupled to the suture ring 220 so that both rotate together. As would be understood by those skilled in the art, the thumb wheel 212 may be ergonomically designed with a width and diameter appropriate to typical hands (or with thumb wheels 212 of various sizes), so that it is easy and comfortable to turn manually while performing a procedure. During the procedure, for example after the suture lock collar 212 has been connected to the second lock collar 214, the thumb wheel 212 may be rotated in the direction of arrow A to wrap more of the suture 210 around the suture ring 220, further pulling the distal pigtail portion 102 into a curl or in a direction opposite that of arrow A to unwrap the suture 210 from the suture ring 220 to allow the distal pigtail portion 102 to straighten to a desired degree. The more the thumb wheel 212 is rotated, the more pronounced is the curling which results. Thus, a desired second loop configuration of the flexible distal pigtail portion 102 may be formed, which may comprise a substantially fully formed loop. Those skilled in the art will understand that the suture 210 may alternatively be tensioned or loosened to adjust the curvature of the distal pigtail portion 102 by twisting and untwisting the suture 210.
In the exemplary embodiment shown in
The initial tensioning may, for example, place the distal pigtail portion 102 in a first loop configuration with a relatively minimal curvature of the flexible distal pigtail portion 102. Further actuation of the thumb wheel 212 in the direction of the arrow A further tensions the suture 210 and draws the distal pigtail portion 102 into a second configuration (e.g., a fully formed pigtail loop). The throw of the first suture lock collar 112 in this configuration may be kept to the minimum distance consistent with making the connection with the second lock collar 114, as the tensioning of the suture 210 may be further adjusted using the thumb wheel 212.
The adjustable lock pigtail loop 200 may also comprise a thumb wheel guard 214 adapted to prevent unintentional movement of the thumb wheel 212 during the procedure. The thumb wheel guard 214 may enclose a majority of the thumb wheel 212, and may comprise an opening 222 having dimensions suitable for the user to operate the adjusting mechanism, for example, using the thumb. The exemplary thumb wheel guard 214 comprises a thumb wheel cover 216 covering the opening 222 when there is no need to use the adjusting system. For example, the cover 216 may be attached to the thumb wheel guard 214 via a hinge 224 and a snap or latch 226. A friction lock 218 may be included in the thumb wheel cover 216 to frictionally engage the surface of the thumb wheel 212, and prevent its rotation once the loop has been properly formed or to maintain a current curvature of the distal pigtail portion 102 at any time. For example, the friction lock 218 may include a mechanical lock and/or may be made of silicone or of another material providing high friction.
As shown in
For example, the inner surface of the thumb wheel 304 may cooperate with the outer surface of the slider suture ring 302 to achieve the desired motion. The thumb wheel 304 may be offset relative to the slider suture ring 302, or surface sculpturing of either or both of the two components may be utilized to obtain the relative motion therebetween. The mechanism 300 according to this embodiment of the invention reduces tangling of the suture while it is drawn tight further simplifying the procedure. For example, as would be understood in the art, the mechanism 300 may be similar to a worm gear engaging a slider or a threaded rod and a nut where the rotating member is held in place longitudinally while the member it engages moves along the threading.
Additional embodiments of the present invention may be devised, that utilize different mechanisms to adjust the tension of the suture as required. In general, these embodiments allow the use of an adjustable lock for a pigtail loop used in a drainage catheter that has a short throw. In these embodiments, locking the adjustable lock forms a fluid and mechanical connection between the two devices, but only partially draws the suture so that the pigtail is coiled to a minimally curved position. If desired, a tighter pigtail loop may be achieved by actuating an adjusting mechanism that may be mounted on the adjustable lock or separate therefrom.
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As described above, typical drainage catheters include an elongated portion with a lumen extending therethrough to a hub which is connected to another device. Because the overall flow passage extends through multiple components and the joints between these components, it can be non-uniform, including restrictions negatively affecting the flow rate and increasing the time required to drain a given amount of fluid.
Exemplary embodiments of the catheter according to the invention comprise an elongated body incorporating an internal suture which exits the catheter at a location separate from the hub. Since the exit port for the suture is not formed in the hub, the hub may be designed to incorporate a flow passage that is more uniform and substantially similar to the lumen extending through the elongate body of the catheter, reducing flow restrictions as compared to conventional hubs and increasing the flow rate therethrough. Specifically, the hub according to one exemplary embodiment is sized so that the elongated body of a drainage catheter may be inserted into the distal end of the hub and advanced therethrough to the proximal end of the hub. The lumen of the catheter thus extends through a large portion of the hub, resulting in a more uniform flow path with fewer discontinuities and restrictions.
As shown more clearly with reference to
The hub 702 according to this embodiment includes a connection portion 708 for mechanically attaching to a connection portion 706 of the elongated body 704. As would be understood by those skilled in the art, the connection portion 708 may comprise any suitable known conventional mechanical attachment. The proximal end 712 of the elongated body 704 extends proximally past the connection portion 706, so that it may be advanced into the catheter receiving portion 714 of the hub 702. In one embodiment, the proximal end 712 may be fluidly connected directly to an external device, such as a receiving bag, additional tubing, etc. Alternatively, a portion of the proximal end 710 of the hub 702 may be included in the overall flow path to the external device.
Standardized connectors such as luers which are configured with a tapered projection on one component and a mating conically shaped element on the other component, have often been utilized to attach fluid conduits. However, a locking system that prevents disassembly of the catheter system by the patient or any other unauthorized person may be desired for certain applications as such disassembly may reduce the efficacy of the procedure or cause injuries or other problems.
Embodiments of the present invention incorporate a J-lock to provide such a ‘permanent’ catheter lock which is not easily disassembled by unauthorized personnel. J-Locks are well suited for applications such as, for example, biopsy needle catheters, which include components subject to sudden motions. In addition, an O-ring may be included for some applications. A conventional J-lock is shown in
As shown in
As the first suture lock collar 112 and the second lock collar 114 are twisted together, the mating lock 816 of the locking arm 810 rides over the ramp 806, and then falls into the relief 808 to fully engage the connector 800 with the second lock collar 114. A step 818 is formed at the edge of the ramp 806 to prevent interference between the locking arm 804 and the corner of the mating arm 802. As described above, in one exemplary embodiment, an O-ring is compressed as the second lock collar 114 is pushed onto the first suture lock collar 112 urging the first suture lock collar 112 axially away from the second lock collar 114 increasing the axial force necessary to pull the first suture lock collar 112 and the second lock collar 114 sufficiently apart for the locking arm 810 to clear the step 818 and ramp 806 allowing the first suture lock collar 112 and the second lock collar 114 to come apart.
As shown in
As the first suture lock collar 112 and the second lock collar 114 are rotated to mate the ramps 826, 828 together, they ride easily over each other until the ends of projections 832, 834 pass one another. At this point, the ramps 826, 828 hook into each other as the O-ring pushes the connector 820 and the ramp 826 distally and the second lock collar 114 and the ramp 828 proximally relative to one another. At this point, the locking arm 824 enters the relief 834 and secures the first connector 820 to the second lock collar 114. After the first suture lock collar 112 and the second lock collar 114 are joined as shown in
As shown in
Those of skill in the art will understand that the ramps and angled surfaces described above may be formed on the inner and/or outer diameter surfaces of the suture lock collar and of the second lock collar, rather than on arms extending therefrom. In those embodiments, the two components do not need to be twisted to be locked together, but rather the locking features may slide over each other when the components are pushed together axially. A similar level of permanent locking thus is achieved without twisting the components, which may simplify the use of the device in certain procedures.
The present invention has been described with reference to specific embodiments, and more specifically to a catheter connector. However, other embodiments may be devised that are applicable to other medical devices that use fluid connections. Accordingly, various modifications and changes may be made to the embodiments, without departing from the broadest spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense.