Patent Application
20060009783
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In various medical applications an implanted catheter is needed to access a patient's circulatory system. The implanted catheter may be utilized for delivery of medication/fluids or retrieval/sampling of blood. For example, it may be desirable to establish a central line (i.e., access to a large vein) for infusion of medications, chemotherapy drugs, antibiotics, anti-nausea medications, blood products, nutrients or fluids. Implanted catheters are also used in dialysis, apheresis, and other applications requiring diversion of a part of the blood flow in the circulatory system for processing or filtering. However, a common problem associated with implanted catheters is the increased risk of infection due to the establishment of this artificial path into the patient's body. The risk of infection increases the longer the catheter remains implanted.
One common approach to decrease the risk of infection is to “tunnel” the proximal end (i.e., the physician access end) of the catheter within the patient's body such that the catheter enters the body at a location that is displaced from the location that that the catheter enters a major blood vessel within the patient's body. For example, a central line may be established by inserting a catheter into the subclavian vein that runs behind the clavicle, but the catheter entry point into the patient's body may be moved away from an area next to the clavicle to an area that is not immediately above the entry point into the subclavian vein. In this process, the actual access to the subclavian vein is still achieved by puncture under the clavicle, but the proximal portion of the catheter is pulled under the skin for 2-4 inches and emerges from the body at a location close to the nipple. This procedure may allow the catheter to stay in place for weeks to months, or even, in some circumstances, for years.
A tunneler may be utilized to assist in the tunneling of a catheter from a surface entry location on the patient's body to a location where the catheter actually enters a vessel into the circulatory system. Such a tunneler is generally made of steel or hard plastic and has a tapered distal end for tunneling through bodily tissue. Typically, the proximal end of the tunneler has a barb for insertion into the lumen of the catheter. In one application, the catheter placement is accomplished by first making a cut-down incision near the neck of the patient, and then making an exit site incision remote from the cut-down incision. The catheter is attached to the tunneler by forcing the proximal barbed end thereof into the lumen of the catheter and sliding a sleeve over the catheter. A sleeve with a larger diameter may be used so that when the tunnel is made, the hole created is sufficiently large to prevent constricting forces from acting on the catheter as it resides in the tunnel. The tunneler with catheter attached is then pushed from the exit site incision toward the cut-down incision, creating a subcutaneous tunnel. When the tip of the tunneler emerges at the cut-down site, it is grasped by the physician, who pulls it through until reaching the sleeve on the tunneler. The sleeve is then pushed off the catheter and the proximal end of the tunneler is pulled out from the catheter lumen. The catheter distal end is then placed into the blood vessel.
Examples of various tunneling and gripping devices are disclosed in U.S. Patent Application Pub. No. US 2004/0006329 A1, titled “DEVICE FOR HOLDING AND GUIDING A GUIDE WIRE IN A CATHETER” by Scheu, published Jan. 8, 2004; U.S. Patent Application Pub. No. US 2004/0039372 A1, titled “OVER-THE-WIRE CATHETER HAVING A SLIDABLE INSTRUCMENT FOR GRIPPING A GUIDEWIRE” by Carmody, published Feb. 26, 2004; U.S. Pat. No. 3,724,882, titled “TUBE-TO-HOSE CONNECTION” issued to Dehar, dated Apr. 3, 1973; U.S. Pat. No. 4,143,893, titled “CLAMPING DEVICE” issued to Fleischer, dated Mar. 13, 1979; U.S. Pat. No. 4,672,979, titled “SUTURE SLEEVE ASSEMBLY” issued to Pohndorf, dated Jun. 16, 1987; U.S. Pat. No. 5,306,240, titled “TUNNELER AND METHOD FOR IMPLANTING SUBCUTANEOUS VASCULAR ACCESS GRAFTS” issued to Berry, dated Apr. 26, 1994; U.S. Pat. No. 5,405,329, titled “INTRAVASCULAR MULTI-LUMEN CATHETER, CAPABLE OF BEING IMPLANTED BY “TUNNELING”” issued to Durand, dated Apr. 11, 1995; U.S. Pat. No. 6,475,244 B2, titled “TUNNELING DEVICE” issued to Herweck et al., dated Nov. 5, 2002; each of which is incorporated herein by reference in its entirety.
One of the disadvantages of the current tunneling devices is that the tunneler must be differently sized for differently sized lumens, as well as the fact that attachment and removal of the barbed end from the lumen of the catheter often results in damage to the lumen and the distal tip of the catheter. Typically, the barb is larger than the diameter of the catheter lumen and thus forces the tip of the catheter to expand radially and makes the tip prone to damage. Another disadvantage is that the barb attachment mechanism of the tunneler may not be suitable for some of the multi-lumen catheters on the market. For example, some of the multi-lumen catheters have raised profiles at the distal lumen openings which may cause abrasion or resistance when it is passed through the bodily tissue. In addition, some catheters have two or more distal tips. Since the traditional tunnelers are designed to secure only one distal tip, it may be difficult to ensure that all of the tips tunnel through the bodily tissue in a proper manner. Furthermore, some of the catheters in the market do not have a distal opening (e.g. Groshong catheter, etc.), preventing the use of a barbed tunneler on the distal end of such a catheter.
Thus, an improved tunneler capable of accommodating various tip configurations and minimizing damage to the catheter may be desirable. It may be preferable to apply gripping/compression forces for securing the catheter to the tunneler throughout a region or portion of the catheter body instead of limiting/focusing the compression force on a small end portion of the catheter. In addition, it may also be desirable to be able to accommodate catheters with a split-tip design, which have an arterial and venous lumen that bifurcates into two separate branches at the distal end of the catheter.
Accordingly, described herein is a tunneling device having a gripping mechanism to secure the catheter by holding onto the body of the catheter (i.e., a distal portion or a proximal portion of the catheter) rather than just the distal tip or proximal end of the catheter. This improved tunneler may prevent damage to the catheter that can be experienced using previous designs that require insertion of a barb(s) or other large protrusion(s) into the distal or proximal lumen of the catheter. In one variation, the tunneling device comprises three parts: a tunneler, a collet and a sheath. The tunneler comprises an elongated body with a tapered distal end for insertion into bodily tissues. The tunneler may be fabricated from surgical steel or other metallic and/or polymeric materials with proper strength to support forces needed to separate tissues such that the tunneler may pass through. The collet may comprise a compression sleeve having a plurality of fingers that are separated and flare outward from a unitary distal end away from the central axis of the device. The collet may be configured for positioning at the proximal end of the tunneler. The compression sleeve may be fabricated from metal, plastic or other polymeric material. The sheath may comprise an oversleeve that can be slid over the tunneler from its distal end toward its proximal end to force the fingers on the collet to compress inward toward the central axis of the tunneler.
To assemble, the compression sleeve is slid over the distal end of the tunneler and advanced toward the proximal end. The flared proximal end of the tunneler may have a greater diameter than the inner lumen of the compression sleeve so that the compression sleeve cannot slide off in a proximal direction. The oversleeve is then slid onto the body of the tunneler. To attach a catheter, either the distal or proximal portion of the catheter is placed within the compression sleeve fingers. The oversleeve is then slid over both the catheter and compression sleeve, compressing the combination. The compression sleeve may have internal ribs to further keep the catheter from movement. The oversleeve may also be dimensioned so that sliding too far in the proximal direction is prevented.
The gripper design implemented at the proximal end of the tunneler may provide various advantages, including but not limited to: 1) tunneling forces may be applied to a region along the shaft of the catheter; 2) compression and tensile forces previously required to attach and detach the catheter from the tunneler may be eliminated; 3) tunneler/catheter interface need not depend on the free space within the lumen of the catheter, nor the specific dimensions and geometry thereof as there is no need to insert a barb or other connection mechanism therein to secure the catheter onto the tunneler; and 4) both arterial and venous tips of a split-tip style catheter may be secured within the sheath by the collet, preventing damage thereof during the tunneling process.
These and other embodiments, features and advantages of the present invention will become more apparent to those skilled in the art when taken with reference to the following more detailed description of the invention in conjunction with the accompanying drawings that are first briefly described.
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are identically numbered. The drawings, which are not necessarily to scale, depict selected preferred embodiments and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
Before describing the present invention, it is to be understood that unless otherwise indicated this invention need not be limited to applications in human. As one of ordinary skill in the art would appreciate, variations of the invention may be applied to other mammals as well. Moreover, it should be understood that embodiments of the present invention may be applied in combination with various catheters, tubing or other elongated and flexible material/device/tissues/organs for insertion of such material/device/tissues/organs into a patient's body.
Furthermore, although variations of the tunneling device disclosed herein may be particularly usefully for gripping the distal portion of a catheter having a special tip design, it is to be understood that the application of the device is not limited procedures requiring gripping of the catheter from the distal end. One of ordinary skill in the art, having the benefit of the disclosures herein, would appreciate that variations of the tunneling device may be used for gripping the proximal portion of a catheter for tunneling into or under tissues.
A hemodialysis catheter implantation is used herein as an example application of the tunneling device to illustrate the various aspects of the invention disclosed herein. In light of the disclosure herein, one of ordinary skill in the art would appreciate that the tunneling device may be applicable for tunneling various elongated instruments or materials through the soft tissues of a patient. It is also contemplated that the tunneling device described herein may be used for tunneling vascular grafts or other harvested or processed tissues or organs through the muscles or other soft tissues in a patient's body. The tunneling device may also be implemented for inserting elongated instruments, materials, or soft tissues through a hollow body organ in a patient's body.
It must also be noted that, as used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, the term “a finger” is intended to mean a single finger or a combination of fingers, “a fluid” is intended to mean one or more fluids, or a mixture thereof.
In one aspect of the invention, the tunneling device comprises an elongated body for tunneling through tissues in a patient, and a gripping mechanism attached to the proximal end of the elongated body for securing either the distal portion or the proximal portion of a catheter within the proximal end of the tunneling device. The gripping mechanism may further comprise a compression mechanism to secure the distal/proximal portion of a catheter or other elongated body within the gripping mechanism. For example, a compression mechanism, such as an oversleeve, may be provided to maintain the compression pressure on the body of the catheter, and thus, prevent the catheter from prematurely detaching from the tunneling device. The distal direction of the tunneler is defined as the direction towards the distal end of the tunneler (e.g., +Z in
In one variation, as shown in
The fingers are configured to receive the distal or proximal portion of a catheter, and secure that portion of the catheter within the fingers such that the tunneler may be used to pull the catheter through an orifice within a patient's body. In light of the disclosure herein, one of ordinary skill in the art would appreciate that the proximal end of the tunneler may be configured with other similar mechanical mechanisms that are well known to one of ordinary skill in the art to receive and secure portion of a catheter. For example, clamps or springs may be used to provide the gripping mechanism to trap the distal or proximal portion of a catheter. Furthermore, although the example shown in
The tunneling device 2 shown in
In another variation, the tunneling device is configured with a detachable gripping mechanism. In one example, the device comprises a collet that can be slidably removed from the tunneler body. As shown in
To assemble the tunneling device, the collet 34 is first slid over the tunneler 32 and advanced to the proximal portion 52 of the tunneler with the extending members 48, 50 of the collet 34 pointing toward the proximal end of the tunneler. The collet 34 is then slid over the raised profile 44 to secure the collet 34 into place. Alternatively, matching helical profiles may be provided on the outer surface of the tunneler' shaft and the inner lumen surface of the collet such that the collet may be screwed into place. Other locking mechanisms that are well known to one of ordinary skill in the art may also be applied to secure the collet. The sheath 36 is then slid over the tunneler 32 from the distal end 38 toward the proximal end 42. The proximal portion of the sheath 36 is then slid over the collet 34 to force the extending members 48, 50 of the collet 34 to compress inward.
Although it is preferred that the collet be configured to receive catheters of various sizes, one may also prepare a plurality of collets of various sizes to receive catheters of different diameters. For example, the size of the fingers and/or the radial expansion of the fingers may vary depending on the particular catheter or ranges of multiple catheters it is designed to support. In addition, differently sized collets may be configured for implementation on the same tunneler. For example, collets of different sizes may be configured with the same proximal lumen size for placement on the same tunneler. In this variation, the operator may select a specific collet size to use in the implant procedure, depending on the size of the catheter to be implanted. For example, a collection of collets may be provided with the inner lumen of each of the collets configured to surround a catheter of a specific French sizes ranging between about 1 French to about 30 French. Furthermore, one of ordinary skilled in the art would appreciate that the collet may be fabricated in various well known configurations.
In the example shown in
In light of the disclosure herein, one of ordinary skill in the art would appreciate that the tunneling device of the present invention may be configured to receive a catheter with various distal tip designs. For example, the gripping mechanism (e.g., collet, compression sleeve, extended fingers, etc.) may be configured to receive catheters with a staggered profile or having a plurality of lumens at the distal portion of the catheter (e.g., a Hickman® dual lumen catheter, BARD Access Systems, SLC, UT, etc.). Alternatively, the gripping mechanism may be configured to receive a catheter with a closed distal tip (e.g., Groshong catheter, etc.) by securing onto the distal portion of the catheter body. As described above, the tunneling device of the present invention may also be configured to receive a hemodialysis catheter having a split-tip configuration, such as the HemoSplit™ catheter, manufactured by Bard Access Systems, Inc. of Salt Lake City, Utah, which is disclosed in U.S. application Ser. No. 10/371,774, filed Feb. 21, 2003, and is incorporated by reference herein in its entirety. Due to the split-tip configuration of such hemodialysis catheters, it may be difficult to utilize a traditional catheter tunneler, which secures the catheter by attaching itself to the distal lumen of the catheter, as the tip section not attached to the tunneler will be left dangling and could suffer damage during a tunneling procedure. The tunneling device of the present invention may be configured with a large enough space between the fingers to receive both branches of the bifurcation, which forms the split-tip configuration, by compressing the distal portions of the two branches together within the proximal portion of the tunneling device. This may allow the physician to pull the split-tip catheter through the channel created by the tunneler without worrying about the possibility that the unsecured branch may get caught in the tissue or cause damage to the tissue during a tunneling procedure.
In another variation, the oversleeve may be configured with mechanisms for securement on the shaft of the tunneler. In addition, mechanisms may be provided to allow the operator to adjust the pressure applied on the catheter. For example,
In another variation, the fingers and/or the proximal cavity may be adapted with padding or other soft and/or flexible interfaces for compressing and/or securing fragile materials, soft tissues or organs (e.g., tissue or organs harvested from the patient or a donor, etc.) for tunneling through the tissue in a patient. For example, the tunneling device may be configured for tunneling a vascular graft through the patient's body in order to position the vascular graft for implantation. In light of the disclosure herein, one of ordinary skill in the art would appreciate that the disclosed tunneling device may be fabricated in various sizes/dimensions and with various materials to accommodate different medical applications.
To utilize the tunneling device shown in
In yet another variation, the tunneling device may be configured without a collet. In one variation, the tunneling device comprises a sleeve 212 extending from the distal portion of a tunneler 216. Within the inner lumen of the sleeve a compressible material, such as a ribbon 210, is positioned to provide the compression force to secure the distal portion of the catheter 214 within the sleeve 212, as shown in
As discussed earlier, the tunneling device may be implemented for tunneling various catheters or other elongated device/materials through a patient's bodily tissue. An example illustrating the implantation of a Hickman® catheter is described above. A first incision is made close to the patient's left nipple, and a second incision is made close to the left clavicle for accessing the subclavian vein. The distal tip portion of the Hickman® catheter is placed within the gripping mechanism of the tunneling device. An oversleeve is advanced toward the proximal end of the tunneling device to compress the gripping mechanism and secure the catheter within the gripping mechanism. The distal end of the tunneling device is then inserted into the first incision. The tunneler may be used to create a path between the first incision and the second incision. The tunneling device is pushed through the tissue to exit at the second incision. The tunneling device is pulled out of the second incision and, in the process, drags a portion of the catheter through the tunneled channel between the first and second incision. The oversleeve is pushed toward the distal end of the catheter to release the catheter from the gripping mechanism. A guidewire, introducer, and tear-away sheath may then be implemented to insert the distal portion of the catheter into the patient's circulatory system through the exposed subclavian vein. The physician may then advance the tip of the catheter towards the superior vena cava-right atrial junction. Once the catheter is put in place, sutures may be used to close the incisions sites as necessary.
In another variation, the catheter may be placed inside of a patient using the retrograde technique. In this approach, the distal tip of the catheter is first inserted into a vein in the patient's body. The proximal end of the catheter is then inserted into the proximal end of the tunneling device. The sleeve is then slid on, to force the gripping mechanism to secure a proximal portion of the catheter within the tunneling device. The tunneling device may then be used to tunneling the proximal end of the catheter under the skin to the final skin exit site.
This invention has been described and specific examples of the invention have been portrayed. While the invention has been described in terms of particular variations and illustrative figures, those of ordinary skill in the art will recognize that the invention is not limited to the variations or figures described. In addition, where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art will recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain of the steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. Therefore, to the extent there are variations of the invention, which are within the spirit of the disclosure or equivalent to the inventions found in the claims, it is the intent that this patent will cover those variations as well. Finally, all publications and patent applications cited in this specification are herein incorporated by reference in their entirety as if each individual publication or patent application were specifically and individually put forth herein.
