Apparatus and method for implanting arteriovenous graft

Abstract

To provide a favorable apparatus and the like.SOLUTION: An apparatus for delivering a vascular arteriovenous graft includes a tubular sleeve 44 defining an internal lumen adapted to be slidably disposed over a tunneling instrument 42. Upon advancement of the tunneling instrument to a desired subcutaneous anatomical location, a shaft is removed while the sleeve remains in a tissue. The sleeve has a linear slit 58 extending from a proximal end to a midpoint of the length of the sleeve. The lumen receives a distal end of the graft and at least a portion of a cannulation chamber. An end portion of the sleeve gradually expands along the slit, providing an enlarged diameter to accommodate the cannulation chamber. A longitudinal force applied to the sleeve from the tissue when the sleeve is removed from the tissue, fixes the graft within the sleeve by radial compression of the sleeve, and the graft and the sleeve are pulled through the tunnel to deploy the vascular graft.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of U.S. Provisional Application Nos. 63 / 166,794 and 63 / 166,790, both filed on Mar. 26, 2021, and incorporates the entire contents of both herein by reference.

[0002] Background Devices and methods for implanting arteriovenous grafts, and more particularly, devices and methods for using tunneling instruments in forming a subcutaneous anatomical tunnel for implanting an arteriovenous graft, including the use of a removable sleeve surrounding the tunneling instrument for delivery of the arteriovenous graft, are described.

Background Art

[0003] An arteriovenous graft is a tubular device suitable for implanting in the body to redirect blood flow between blood vessels. The surgical implantation of an arteriovenous graft requires placing the graft within the subcutaneous tissue. The first step of the implantation procedure is to create a subcutaneous anatomical pathway, i.e., a "tunnel," through which the arteriovenous graft is passed between the anastomosis sites, which is commonly referred to as the graft tunnel. This is a necessary surgical step in all peripheral vascular access and peripheral vascular procedures for additional anatomical graft locations. The arteriovenous graft is placed within a tunnel in body tissue to secure the graft to an existing peripheral blood vessel and form a bypass around the blood vessel or a portion thereof, or to form an arterial and venous connection for creating an arteriovenous shunt. A vascular graft can also connect artery to artery.

[0004] Conventional tunneling devices include a long, rigid rod having a handle at the proximal end and a bullet-shaped tip at the distal end. The rod can be of various sizes and shapes, having a straight shaft, a curved shaft, or a semi-circular shaft, thereby enabling various graft placement positions and locations. In the tunneling procedure, a first proximal incision and a second distal incision are made in the selected anastomosis region. The tip of the distal end of the tunneling device is inserted into the proximal incision. The tip of the tunneling device is then forced through the subcutaneous tissue to form a path between the incisions by blunt dissection until the tip protrudes from the distal incision. Once the tip is exposed, the proximal end of the arteriovenous graft is tied to the distal end or tip of the tunneling device with a sterile suture. The tunneling instrument and the attached arteriovenous graft are then pulled proximally along a path through the previously created graft tunnel until the proximal end of the arteriovenous graft extends from the proximal incision. When the arteriovenous graft is properly positioned, the graft is detached from the distal end of the tunneling device and a portion of the graft is removed. An anastomosis is formed between the end of the graft and the blood vessels surrounding the vascular region to be bypassed, and the incisions are closed.

[0005] The step of pulling the tunneling instrument and the attached arteriovenous graft through the graft tunnel can require considerable force. The required force depends on several factors, including the relative sizes of the graft tunnel and the graft and the material of the graft. Conventional delivery systems for arteriovenous grafts and other implantable devices are sometimes covered with a retention sleeve that reduces friction when passing through the subcutaneous tissue. After the implant procedure, the sleeve is removed by pulling or winding it back on the device to retract the sleeve. Rotating the sleeve during retraction reduces the required pulling force compared to sliding the sleeve out on the device, but considerable force may still be required to retract the sleeve after the implant procedure of the arteriovenous graft.

[0006] For the reasons described above, there is a need for an apparatus and method for implanting an arteriovenous graft to minimize the force required to deliver the graft. A new device in the form of a sleeve should define and assist in supporting the length of the anatomical tunnel formed by the tunneling device. The sleeve should be able to be withdrawn in a reliable manner with low tensile force to minimize problems associated with excessive axial force on the sleeve during retraction. The new apparatus and method should also be able to implant any type of vascular graft, including but not limited to ePTFE and natural tissue grafts, in an implant procedure. SUMMARY OF THE INVENTION

[0007] Abstract An apparatus is provided for subcutaneously delivering an arteriovenous graft having a cannula insertion chamber and having a length extending along a longitudinal axis between a proximal end and a distal end into a patient's tissue. The apparatus uses a rigid tunneling instrument including a long shaft having a handle at a proximal end of the shaft and a removable tip at a distal end of the shaft to form a passageway in the subcutaneous tissue. The subcutaneous delivery device includes an elongate tubular sleeve having a length and defining a lumen, and the sleeve is adapted to be slidably disposed over at least a portion of the shaft of the tunneling instrument between the handle and the tip. When the tunneling instrument advances to a desired subcutaneous anatomical location, the shaft is selectively removed from the sleeve while the sleeve remains disposed at the desired anatomical location. The sleeve has a linear slit extending along the length of the sleeve from a proximal end to a midpoint of the length of the sleeve. The lumen defined at the proximal end of the sleeve is adapted to receive at least a portion of the distal end of the graft and the cannula insertion chamber, whereby the proximal end portion of the sleeve gradually expands along the slit to provide an enlarged diameter for accommodating the cannula insertion chamber. Applying a longitudinal force to the sleeve from the distal end of the sleeve moves the sleeve distally when removing the sleeve from the tissue, thereby pulling the graft and the sleeve through the tunnel and being effective to fix the graft within the sleeve by radial compression of the sleeve to deploy the vascular graft.

[0008] In one aspect, the sleeve is adapted to receive substantially the entire length of the shaft between the handle and the tip. In another aspect, the sleeve is uniformly tapered from a proximal end to a distal end such that the distal end has a reduced diameter from the proximal end.

[0009] In one embodiment, the sleeve includes an enlarged diameter portion adjacent the proximal end and adapted to receive the cannula insertion chamber.

[0010] Also provided is an apparatus for subcutaneously implanting an arteriovenous graft, which includes a cannula insertion chamber and has a proximal end, a distal end, and a length extending along a longitudinal axis between the proximal end and the distal end, into a patient's tissue. The subcutaneous implant apparatus includes a rigid tunneling instrument for forming a passageway within the subcutaneous tissue. The tunneling instrument includes a long shaft having a handle at the proximal end of the shaft and a removable tip at the distal end of the shaft. The long tubular sleeve has a length and defines a lumen. A linear slit extends along the length of the sleeve from the proximal end to an intermediate point of the length of the sleeve. The sleeve is configured to be slidably disposed over at least a portion of the shaft of the tunneling instrument between the handle and the tip. When the tunneling instrument advances to a desired subcutaneous anatomical position, the shaft is selectively removed from the sleeve while the sleeve is disposed in the anatomical position. The lumen is adapted to receive at least a portion of the distal end of the graft and the cannula insertion chamber through the proximal end of the sleeve, whereby the proximal end portion of the sleeve gradually expands along the slit to provide an enlarged diameter for accommodating the cannula insertion chamber. Applying a longitudinal force to the sleeve from the distal end of the sleeve moves the sleeve distally to remove the sleeve from the tissue, thereby being effective to fix the arteriovenous graft within the sleeve by radial compression of the tissue around the sleeve. The arteriovenous graft and the sleeve are pulled through the tunnel to deploy the vascular graft.

[0011] In one aspect, the sleeve is adapted to receive substantially the entire length of the shaft between the handle and the tip. In another aspect, the sleeve is uniformly tapered from the proximal end to the distal end such that the distal end has a reduced diameter from the proximal end.

[0012] In one embodiment, the sleeve includes an enlarged diameter portion adjacent the proximal end and adapted to receive the cannula insertion chamber.

[0013] The sleeve is characterized in that it has a wall at its proximal end, and the wall has an axial opening for receiving the tip of the tunneling instrument for connecting the sleeve to the tunneling instrument. A clip including a pin, the shaft having a hole adjacent to the tip defining an axial passage for receiving the pin for connecting the shaft to the sleeve to apply a tensile force in the proximal direction.

[0014] A system for subcutaneous delivery of a medical device into a patient is provided. The subcutaneous delivery system includes a tunneling instrument having a shaft with a proximal end and a distal end, a vascular graft having a length, a distal end, a proximal end, an outer surface, and a longitudinal axis, and a sleeve having a length and disposed on a substantial portion of the outer surface of the shaft. The sleeve is configured to apply a radial pressure to the cannula insertion chamber and move the sleeve distally during removal of the sleeve when a longitudinal force is applied distally to the sleeve for implanting the vascular graft.

[0015] In one aspect, the sleeve is adapted to receive substantially the entire length of the shaft between the handle and the tip. In another aspect, the sleeve is uniformly tapered from the proximal end to the distal end such that the distal end has a reduced diameter from the proximal end.

[0016] In one embodiment, the sleeve includes an enlarged diameter portion adjacent to the proximal end adapted to receive a cannula insertion chamber.

[0017] The sleeve is characterized in that it has a wall at its proximal end, and the wall has an axial opening for receiving the tip of the tunneling instrument for connecting the sleeve to the tunneling instrument.

[0018] In another embodiment, the subcutaneous delivery system can further include a clip including a pin, and the shaft has a hole adjacent to the tip defining an axial passage for receiving the pin for connecting the shaft to the sleeve to apply a tensile force in the proximal direction.

[0019] A method of subcutaneously implanting an arteriovenous graft into a target tissue is also provided. The arteriovenous graft includes a cannula insertion chamber, a proximal end and a distal end, and a length extending along a longitudinal axis between the proximal end and the distal end. The implanting method includes the step of incising the target tissue at a first proximal position and a second distal position spaced apart from the first proximal position. A rigid tunneling instrument is provided that includes a long shaft having a handle at the proximal end of the shaft and a removable tip at the distal end of the shaft. The tip is removed, and a tubular sleeve is placed over at least a portion of the shaft between the tip and the handle. The sleeve has a slit extending along the length of the sleeve from the proximal end to a midpoint of the length of the sleeve. The tip is fixed to the distal end of the shaft and inserted into the first incision. The user advances the instrument and the sleeve subcutaneously through the tissue along a passageway until the tip exits the second incision such that the distal end of the sleeve extends from the second incision and the proximal end of the sleeve extends from the first incision. The tip is removed, and then the tunneling instrument is pulled proximally by the handle to remove the shaft from the sleeve within the tissue. The distal end of the graft is inserted into the proximal end of the sleeve until the cannula insertion chamber of the graft is at least partially within the sleeve and the sleeve expands along the slit to accommodate at least a portion of the chamber. The method includes the step of pulling the sleeve distally to withdraw the sleeve from the tissue while the proximal end of the sleeve is compressed by the excised tissue defining the tunnel, pressing the sleeve against the chamber, and pulling the graft through the tissue together with the sleeve.

[0020] In one aspect, the method can further include the step of pulling the proximal end of the arteriovenous graft proximally to withdraw the cannula insertion chamber of the arteriovenous graft into the tissue. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Brief Description of the Drawings To more fully understand the devices and methods used to form subcutaneous anatomical tunnels, reference should be made to the embodiments shown in the accompanying drawings and described below. In the drawings,

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DETAILED DESCRIPTION OF THE INVENTION

[0042] Description In this specification, certain terms are used for convenience only and should not be construed as limiting. For example, words such as "upper", "lower", "left", "right", "horizontal", "vertical", "upward", "downward", "top", "bottom", etc. merely describe the configuration shown in the figures. In reality, the components can be oriented in any direction, and thus, unless otherwise specified, the terms should be understood to encompass such variations. The words "interior" and "exterior" refer to the direction towards and away from the geometric center of the core and its designated portion, respectively. This term includes the words specifically mentioned above, their derivatives, and words having similar meanings.

[0043] Referring now to the drawings, like reference numerals refer to corresponding or like elements throughout several views, and an embodiment of an apparatus for forming a subcutaneous anatomical tunnel for implanting an arteriovenous graft in a patient is shown in FIG. 1 and is generally designated 40. The tunnel forming and implanting apparatus 40 includes a tunneling instrument 42, also referred to herein as a “tunneling device,” a tubular sleeve 44, and an arteriovenous graft 46. The tunneling instrument 42 includes an elongate rigid shaft 48, a proximal handle 50 at one end of the shaft, and a removable distal tip 52 at the other end of the shaft. The tip 52 generally has a bullet shape or, alternatively, an oval or circular shape with an increasing diameter from a pointed distal end. During the tunneling procedure, the shaft 48 and tip 52 are advanced through the subcutaneous tissue by applying an axial force in the distal direction on the handle 50, and the tip facilitates a blunt dissection of tissue characteristic of the tunneling procedure. The shaft 50 and tip 52 can be made of stainless steel, although those skilled in the art will recognize that other materials may be suitable. One such example of an alternative material is a plastic such as a rigid plastic. A suitable tunneling instrument is the Kelly-Wick Tunneler available from C.R.Bard, Inc. of Moncks Corner, South Carolina.

[0044] An arteriovenous graft 46 suitable for use in this apparatus and method is described in U.S. Patent No. 9,585,998, the entire content of which is incorporated herein by reference. The arteriovenous graft 46 includes a conduit 132 having a first end 134 and a second end 136. The first end 134 is configured to be connected at its end to a first blood vessel of a subject, such as an artery. The second end 136 is configured to be connected at its end to a second blood vessel of a subject, such as a vein. In this regard, blood flows through the conduit 132 from the first end 134 to the second end 136. At least one cannula insertion chamber 140 is disposed between the first end 134 and the second end 136 of the conduit 132. The conduit 132 extends through the chamber 140. The cannula insertion chamber 140 has an open front portion that defines a cannula insertion port configured to receive a dialysis needle. It is understood that the tunneling device can be used not only for natural tissue grafts or fistulas, but also for any vascular graft.

[0045] Referring to FIGS. 2-7, the tubular sleeve 44 includes a hollow tube that is open at both a proximal end 54 and a distal end 56. In one embodiment, the diameter of the sleeve 44 tapers from the proximal end 54 towards the distal end 56. The diameter of the sleeve 44 at the distal end 56 is smaller than the maximum dimension of the tip 52. As shown in FIG. 8, the sleeve 44 is proximally engaged with the tip 52 of the tunneling instrument 42 and extends to the handle 50 of the tunneling instrument 42. The sleeve 44 is sized such that its diameter and length are slidably disposed over the shaft 48 of the tunneling instrument 42 during the tunneling procedure and surround at least a portion of the shaft 48. Following the tunneling of the tissue, when a tensile force is applied to the handle 50 in the proximal direction along the longitudinal axis of the shaft 48, the tip 52 is removed and the shaft 48 is withdrawn from the sleeve 44. The sleeve 44 remains within the tissue and provides for the insertion of the graft 46 through the tunneled tissue path due to the unrestricted flexibility of the surface of the sleeve 44.

[0046] As best seen in FIGS. 6 and 7, sleeve 44 has a linear slit 58 that extends from the open proximal end 54 to a position along the longitudinal axis of the sleeve along the length of the sleeve 44. The slit 58 can generally be oriented linearly or helically (not shown) along the length of the sleeve 44. The slit 58 allows the sleeve 44 to expand at the slit when the arteriovenous graft is inserted into the proximal end 54 of the sleeve. In the illustrated embodiment, the sleeve 44 has holes 60 at the ends of the slit 58 to prevent the sleeve from tearing from the slit 58 when the sleeve is expanded. The slit 58 can vary in length and shape. If the slit is shorter, it can only receive a smaller area of the cannula insertion chamber 140 and can reduce surface damage. If the slit 58 is longer, it allows the cannula insertion chamber 140 to be more fully received in order to better clamp the cannula insertion chamber 140 during delivery to reduce the risk that the sleeve will be released before the graft 46 is fully within the anatomical tunnel. The opening of the slit 58 can also have different shapes. FIG. 15 shows the removal of material from the proximal end 54 of the sleeve 44 to form a triangular opening. Similarly, FIG. 16 shows the slit 58 forming a linear opening for receiving the cannula insertion chamber 140. Multiple slits (not shown) can also be used. Multiple slits allow a larger cannula insertion chamber 140 to be inserted into the sleeve 44 and clamped by the sleeve 44. It is understood that the slit 58 at the end of the sleeve 44 is not necessary when the sleeve is used for the deployment of a conventional biological graft. In this application, the lumen is larger than the diameter of the graft, so no slit is needed. The graft can simply be slidable within the sleeve 44 in the tissue, and the sleeve 44 is withdrawn from the tissue leaving the graft behind.

[0047] The sleeve 44 can be made from any biocompatible material that is smooth, flexible, and compressible. Suitable materials can be porous, non-porous, permeable, or impermeable. Since the sleeve material does not bend excessively, the sleeve 44 can absorb the tensile forces applied during tunneling and deployment of the graft 46. Examples of such materials include, but are not limited to, silk, silicone, fluoropolymers such as expanded polytetrafluoroethylene (ePTFE), high-density polyethylene (HDPE), and other polymers such as polyester and polyimide. Suitable materials are available from Colorite of Ridgefield, New Jersey. By varying the material and properties of the sleeve, such as thickness and width, various desired configurations can be achieved. The sleeve 44 may be extruded. It is understood that the sleeve 44 can have a coefficient of friction low enough to allow the sleeve to be removed from the anatomical tunnel by an axial tensile force applied to the sleeve.

[0048] In another embodiment, the sleeve 44 has a "double-wall" structure. The double-wall sleeve is formed from a double layer of thin, flexible, and compressible material with both ends closed. The inner portion or first wall of the sleeve 44 has a predetermined durometer and extends radially and axially along the sleeve from the proximal end 54 of the sleeve to the distal end 56 of the sleeve. The outer portion or second wall of the sleeve extends radially and axially along the inner portion from the proximal end 54 to the distal end 56 of the sleeve 44. The durometer of the inner portion of the double-wall sleeve 44 is less than that of the outer portion, providing a more flexible inner portion that surrounds the graft 46 to prevent damage during deployment and a harder outer shell for the sleeve.

[0049] The smooth outer surface of the sleeve material can reduce the coefficient of friction of the sleeve 44. As a result, the tunneling instrument 42 and the sleeve 44 can be easily inserted through the tissue with less trauma, less friction, less blunt dissection, and less dragging during placement. Due to the smoothness and low profile of the sleeve 44 with respect to the shaft 48, the sleeve does not substantially increase the outer diameter of the tunneling instrument 42.

[0050] The sleeve 44 may optionally be coated with a lubricious substance to provide a low coefficient of friction, assist in the insertion and movement of the sleeve 44 and the associated tunneling instrument 42 through the tissue, and at the same time minimize tissue dragging and trauma during insertion or during removal of the sleeve after the implant procedure. Thereby, tissue dragging and tissue trauma during insertion of the tunneling instrument 42 and the sleeve 44, or during removal of the sleeve 44 during the implant procedure of the graft 46, are minimized. It is understood that various coatings containing therapeutic agents are available for the delivery of therapeutic materials. Solid lubricants (i.e., graphite, wax, silicone), fluid lubricants (i.e., hydrocarbon oil, silicone oil), gels (i.e., hydrogel), or any other biocompatible material known in the art can be used. In one embodiment, the sleeve 44 can be coated or wetted immediately prior to use. In another embodiment, the applicant contemplates a kit that includes the sleeve 44 and a wetting agent for wetting the sleeve. In another embodiment, the kit includes the sleeve 44, the arteriovenous graft 46, and a wetting agent for wetting the sleeve.

[0051] During use, first, a first proximal incision 80 and a second distal incision 82 spaced from the first incision are formed in the subcutaneous tissue below through the patient's skin 78. The tip 52 at the distal end 53 of the tunneling instrument 42 is inserted into the first incision 80 together with the sleeve 44 on the shaft 48, and then pushed horizontally through the subcutaneous tissue along the path until the tip exits the second incision 82 (FIG. 10). Next, the tip 52 is removed by the surgeon, and the tunneling instrument 42 is pulled proximally from the first incision 80 by the handle 50 to remove the shaft 48 from the tissue. The sleeve 44 remains in the body tissue. As shown in FIG. 11, the ends 54, 56 of the sleeve 44 extend proximally and distally from the first and second incisions 80, 82 outside the skin 78.

[0052] The distal end portion 136 of the graft 46 is inserted into the proximal end 54 of the sleeve 44 until the cannula insertion chamber 140 is at least partially within the sleeve 44 (FIG. 12). The sleeve 44 allows the surgeon to easily push the vascular graft 46 into the lumen defined by the sleeve, which is sized larger than the outer diameter of the conduit 132 of the vascular graft 46. However, the sleeve 44 is configured such that the outer diameter of the cannula insertion chamber 140 is larger than the inner diameter of the sleeve. Thus, the cannula insertion chamber 140 expands the sleeve 44 along the slit 58 to accommodate at least a portion of the chamber (FIG. 12). The distal end of the sleeve 44 extends sufficiently externally from the distal incision 82 so that it can be pulled to withdraw the sleeve from the tissue. After the distal portion of the graft 46 is placed within the sleeve 44, the sleeve 44 is pulled and the proximal end 54 of the sleeve 44 is compressed by the excised tissue that defines the tunnel, thereby pressing the sleeve against the cannula insertion chamber 140. The sleeve 44 is pulled in the axially distal direction while pulling the arteriovenous graft 46 into the tissue 78 until the sleeve 44 is withdrawn from the tissue. The pulling force withdraws the sleeve 44 from the distal incision 82 and gradually moves the arteriovenous graft 46 distally into the tissue 78 through the first incision 80. Without the tissue compressing the sleeve 44 against the cannula insertion chamber, the proximal end 54 of the sleeve 44 expands and releases the arteriovenous graft 46 as the proximal end 54 of the sleeve passes through the distal incision 82. The arteriovenous graft 46 remains within the tissue extending from the incision (FIG. 14). The pulling force is indicated by the arrow. Next, the proximal end 54 of the arteriovenous graft 46 is pulled proximally to retract the cannula insertion chamber 140 of the arteriovenous graft 46 into the tissue 78.

[0053] In another embodiment of a method of delivering an arteriovenous graft 46, the cannula insertion chamber 140 is held in a desired anatomical position through the skin 78, while the sleeve 44 is axially distally pulled relative to the arteriovenous graft 46 and can be withdrawn from the subcutaneous tissue path through a second incision 82. Specifically, once the arteriovenous graft 46 is placed subcutaneously as desired, the surgeon holds the graft 46 in place by pushing the graft across the skin. With continued pulling, the sleeve 44 is pulled off the arteriovenous graft 46 by a given pulling force. The graft 46 remains within the anatomical subcutaneous tunnel. The surgeon then forms anastomoses at each conduit end 134, 136 of the graft 10 by suturing the ends of the graft to the blood vessels at the desired locations.

[0054] In another embodiment, the proximal end 54 of the sleeve 44 can be mechanically fixed to the distal end 53 of the tunneling device 42 adjacent the tip 52 by mechanical or interference fit, mechanical structure, thermal adhesion, or by a biocompatible adhesive or other fixing means. Examples of adhesives are thermoplastic fluoropolymers such as fluorinated ethylene propylene (FEP). Other simple mechanical means are possible and include compression fit collars, staples or sutures, or other fastening techniques acceptable for implant procedures within body tissue.

[0055] In the embodiment shown in FIGS. 17A and 17B, the proximal end 54 of the sleeve 44 includes an end wall 57 having a reduced axial opening 62 with a diameter smaller than the maximum diameter of the tip 52. Since the material of the sleeve 44 is a semi - elastic material, the tip portion 52 can be pushed through the opening 62, but cannot be easily removed because the diameter of the tip 52 is larger than the opening 62. Thus, the sleeve 44 is fixed to the distal end of the tunneling device 42.

[0056] Referring now to FIG. 18, in another embodiment, the distal end of the tunneling instrument 42 can be mechanically fixed to the proximal end 54 of the sleeve 44 using a fastening element for securing the sleeve. The fastening element is directly fixed to the tunneling instrument 42 and is generally designated by 70. The fastening element 70 includes a snap clip that can be used to couple the sleeve 44 to the shaft 48, whereby the sleeve 44 is coupled to and surrounds at least a portion of the distal end and the tip 52 of the tunneling instrument 42. This fastening clip includes a C-shaped body 72 and a pin 74 centrally located in the same plane as the body 72 and extending radially inwardly toward an opening defined by the body 72. The clip 70 is configured to receive and surround a portion of the proximal end 54 of the sleeve 44. The distal end of the shaft, spaced from the tip 52, defines a hole 76 configured to receive the pin 74. The proximal end 54 of the sleeve 44 is surrounded by the clip 70. The sleeve 44 can be coupled to the tip 51 by passing the sleeve 44 over the tip 52 and attaching the clip 70 over the sleeve 44. Thereby, the arms of the body 72 expand outwardly together until they exceed the maximum diameter of the sleeve 44, and the pin 74 is guided through the sleeve 44 into the hole 76 in the shaft until the pin seats in the hole. The arms of the clip 70 can then snap inwardly. Thereby, the sleeve 44 and the tunneling instrument 42 are fixed together with the clip 70. The user can draw the graft 46 into a subcutaneous tunnel preformed by the tunneling instrument 42. It is understood that the clip 70 is fixed by sliding only the ends 134, 136 of the graft 46 over the tip 52 of the tunneling instrument 42 and fixing the graft with the clip 70.

[0057] During use, after the distal end of the tunneling instrument 42 without the sleeve 44 exits the second distal incision 82, the proximal end of the sleeve 44 is fixed to the tip 52. After attaching the sleeve 44 to the tunneling instrument 42, the sleeve 44 extends distally from the distal end of the tunneling instrument 42. The tunneling instrument 42 is withdrawn proximally while pulling the sleeve 44 through the pre-incised tissue that defines the anatomical tunnel. When the sleeve 44 is pulled into the region of the first incision 80, the proximal end of the sleeve 44 is detached from the distal end of the tunneling instrument 42. The sleeve 44 remains within the tissue, forming an internal passage through the sleeve, which is large enough to allow the next passage of the graft 46. The graft 46 is loaded proximally as described above, and the sleeve 44 is pulled distally, whereby the attached graft 46 is simultaneously pulled into the tunnel together with the sleeve 44 and passes through the tunnel until the proximal end 54 of the graft 46 exits the second incision 82. The sleeve 44 allows the surgeon to easily pull the vascular graft 46 through the anatomical tunnel using a sleeve 44 sized substantially larger compared to the outer diameter of the vascular graft 46.

[0058] FIG. 19 shows an embodiment of an apparatus including a sleeve 44 having an enlarged bulbous portion 110 spaced from the ends 54, 56 for receiving the cannula insertion chamber 40 of the graft 46. The enlarged diameter of the bulbous portion 110 of the sleeve 44 allows the sleeve 44 to receive the entire cannula insertion chamber 140 of the graft 46. Some force may be required to attach the graft 46 within the lumen of the sleeve 44.

[0059] FIG. 20 shows an embodiment where the sleeve is generally designated 200. The sleeve 200 is a fabric, and each of the threads 202 of the fabric can move independently of one another. The sleeve functions in the same manner as the previous embodiments.

[0060] An apparatus and method for implanting an arteriovenous graft, including a sleeve 44 surrounding a tunneling instrument 42 for deploying a graft 46 during an implant procedure, has a number of advantages including non-invasive implantation of the arteriovenous graft 46 and subsequent withdrawal of the associated sleeve 44. The sleeve 44 is simply added to a conventional tunneling instrument. The sleeve provides a flexible, compressible yet still rigid outer surface to the shaft 48 of the tunneling instrument 42, allowing for easier tunneling with less friction, resistance, and associated tissue damage during passage of the tunneling device in forming an anatomical tunnel. Inserting the graft 46 into the tissue cavity along with the sleeve 44 results in less trauma, friction, and drag during placement. Thus, the systems and methods described herein can reduce the damaging forces to the surrounding tissue associated with the implant procedure and minimize the resulting trauma to this tissue and its healing response. Due to the smoothness and collapsible low profile of the sleeve 44, the tunneling procedure can be made faster and easier. This delivery system allows the surgeon to avoid using sutures to attach the graft to the tunneler. This facilitates immediate or early cannulation of the vascular graft to be subsequently implanted.

[0061] An embodiment of the tunneling device as described herein is shown being used in a procedure using a vascular graft suitable for implant procedures within the body and is used to re-establish or redirect blood flow beyond an occluded region. The implant procedure is a surgical step required in all peripheral vascular access and peripheral vascular procedures for additional anatomical graft sites. An arteriovenous graft is placed within a tunnel in body tissue to secure a graft to an existing peripheral vessel and form a bypass around the vessel or a portion thereof, or to form an arterial-to-venous connection to form an arteriovenous shunt. The vascular graft can also connect artery to artery. Also, one of ordinary skill in the art will recognize that the embodiments of the tunneling device as described are not directed to a particular vascular graft design and are generally applicable to many different types of vascular grafts that can be synthetic grafts or natural tissue grafts made from different materials. Thus, it is understood that several of the tunneling devices described and illustrated herein can be used with more arteriovenous grafts than shown in the drawings, including grafts without cannula insertion chambers, biological grafts, and fistulas. Further, this device and method can also be used in other surgical implant procedures that require placement of a medical device or other object within subcutaneous tissue.

Claims

1. 1. An apparatus for subcutaneously delivering a vascular arteriovenous graft into tissue of a patient, the graft including a cannulation chamber and having proximal and distal ends and a length extending along a longitudinal axis between said proximal and distal ends, the subcutaneous delivery apparatus using a rigid tunneling instrument including an elongated shaft having a handle at a proximal end of the shaft and having a removable tip at a distal end of the shaft to form a passageway in the subcutaneous tissue, the subcutaneous delivery apparatus comprising: an elongate tubular sleeve having a length and defining an internal lumen, said sleeve adapted to be slidably disposed over at least a portion of said tunneling instrument shaft between said handle and said tip, whereby upon advancement of said tunneling instrument to a desired subcutaneous anatomical location, said shaft is selectively removed from said sleeve while said sleeve remains disposed at the desired anatomical location, said sleeve having a slit extending along a length of said sleeve from a proximal end to a midpoint of the length of the sleeve; a lumen defined at the proximal end of the sleeve adapted to receive the distal end of the graft and at least a portion of the cannulation chamber, whereby the proximal end portion of the sleeve gradually expands along the slit to provide an enlarged diameter to accommodate the cannulation chamber; and A subcutaneous delivery device, wherein application of a longitudinal force to the sleeve from a distal end of the sleeve is effective to move the sleeve distally when removing the sleeve from tissue, thereby pulling the graft and the sleeve through a tunnel and causing radial compression of the sleeve to secure the graft within the sleeve for deploying a vascular graft.

2. The subcutaneous delivery device of claim 1 , wherein the sleeve is adapted to receive substantially the entire length of the shaft between the handle and the tip.

3. The subcutaneous delivery device of claim 1 , wherein the sleeve is uniformly tapered from the proximal end to the distal end such that the distal end has a reduced diameter from the proximal end.

4. The subcutaneous delivery device of claim 1 , wherein the slit is linear.

5. The subcutaneous delivery device of claim 1 , wherein the sleeve includes an enlarged diameter portion adjacent the proximal end, the enlarged diameter portion of the sleeve adapted to receive the cannulation chamber.

6. 1. An apparatus for subcutaneously implanting a vascular arteriovenous graft into tissue of a patient, the graft including a cannulated chamber, the graft having proximal and distal ends and a length extending along a longitudinal axis between the proximal and distal ends, the subcutaneous implantation apparatus comprising: a rigid tunneling instrument for forming a passageway within the subcutaneous tissue; wherein the tunneling tool comprises: an elongate shaft having a handle at a proximal end of the shaft; and a removable tip at a distal end of the shaft; It has an elongate tubular sleeve having a length and defining an internal lumen, said sleeve having a slit extending along a length of the sleeve from a proximal end to a midpoint of the length of the sleeve, said sleeve configured to be slidably disposed over at least a portion of the shaft of the tunneling instrument between the handle and the tip; Contains Once the tunneling instrument has been advanced to a desired subcutaneous anatomical location, the shaft is selectively removed from the sleeve while the sleeve remains in place at the anatomical location; the lumen is adapted to receive the distal end of the graft and at least a portion of the cannulation chamber through the proximal end of the sleeve, whereby the proximal end portion of the sleeve gradually expands along the slit to provide an enlarged diameter to accommodate the cannulation chamber; and A subcutaneous implant treatment device, wherein application of a longitudinal force to the sleeve from a distal end of the sleeve is effective to move the sleeve distally to remove the sleeve from tissue, thereby pulling the arteriovenous graft and the sleeve through a tunnel and causing the arteriovenous graft to be secured within the sleeve by radial compression of tissue around the sleeve to deploy a vascular graft.

7. The subcutaneous implant treatment device of claim 6 , wherein the sleeve is configured to receive substantially the entire length of the shaft between the handle and the tip.

8. 7. The subcutaneous implant treatment device of claim 6, wherein the sleeve is uniformly tapered from the proximal end to the distal end such that the distal end has a reduced diameter from the proximal end.

9. The subcutaneous implant treatment device of claim 6 , wherein the slit is linear.

10. The subcutaneous implantation device of claim 6 , wherein the sleeve includes an enlarged diameter portion adjacent the proximal end, the enlarged diameter portion adapted to receive the cannulation chamber.

11. The implant treatment apparatus of claim 6 , wherein the sleeve includes an end wall at the proximal end, the wall having an axial opening for receiving a tip of the tunneling instrument to connect the sleeve to the tunneling instrument.

12. 7. The subcutaneous delivery device of claim 6, further comprising a clip including a pin, the shaft having a hole adjacent the tip defining an axial passage for receiving the pin and capturing the sleeve between the clip and the shaft.

13. 1. A system for subcutaneous delivery of a medical device into a patient, the subcutaneous delivery device comprising:

1. A rigid tunneling device for forming a passageway in subcutaneous tissue, said tunneling device comprising: an elongate shaft having a handle at a proximal end of the shaft; and a removable tip at a distal end of said shaft; Contains a vascular arteriovenous graft including a cannulated chamber and having a proximal end and a distal end and a length extending along a longitudinal axis between the proximal end and the distal end; an elongate tubular sleeve having a length and defining an internal lumen, said sleeve having a slit extending along a length of the sleeve from a proximal end to a midpoint of the length of the sleeve, said sleeve configured to be slidably positioned over at least a portion of said tunneling instrument between said handle and said tip; Contains Once the tunneling instrument has been advanced to a desired subcutaneous anatomical location, the shaft is selectively removed from the sleeve while the sleeve remains in place at the anatomical location; the lumen is configured to receive the distal end of the graft and at least a portion of the cannulation chamber through the proximal end of the sleeve, whereby the proximal end portion of the sleeve is configured to gradually expand along a slit to provide an enlarged diameter to accommodate the cannulation chamber; and A subcutaneous delivery system, wherein application of a longitudinal force to the sleeve from a distal end of the sleeve is effective to move the sleeve distally to remove the sleeve from tissue, thereby pulling the arteriovenous graft and the sleeve through a tunnel and causing the arteriovenous graft to be secured within the sleeve by radial compression of tissue around the sleeve to deploy a vascular graft.

14. The subcutaneous delivery system of claim 13 , wherein the sleeve is configured to receive substantially the entire length of the shaft between the handle and the tip.

15. The subcutaneous delivery system of claim 13 , wherein the sleeve is uniformly tapered from the proximal end to the distal end such that the distal end has a reduced diameter from the proximal end.

16. The subcutaneous delivery system of claim 13 , wherein the slit is linear.

17. The subcutaneous delivery system of claim 13 , wherein the sleeve includes an enlarged diameter portion adjacent the proximal end, the enlarged diameter portion adapted to receive the cannulation chamber.

18. The subcutaneous delivery system of claim 13 , wherein the sleeve includes a wall at the proximal end, the wall having an axial opening for receiving a tip of the tunneling instrument to connect the sleeve to the tunneling instrument.

19. 14. The subcutaneous delivery system of claim 13, further comprising a clip including a pin, the shaft having a hole adjacent the tip defining an axial passage for receiving the pin to connect the shaft to the sleeve and apply a pulling force in a proximal direction.

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