EP-4312816-B1 - APPARATUS FOR IMPLANTING AN ARTERIOVENOUS GRAFT

Inventors

• GAGE, Shawn M.
• LUCAS, JOHN
• NICHOLS, Craig
• KNIGHT, JOSEPH
• CHIOSONNE, Juan
• LAWSON, PETER
• BUSCH, Samantha
• WALSH, BRIAN

Dates

Publication Date

20260506

Application Date

20211230

Claims (4)

1. An apparatus (40) for subcutaneous delivery in tissue of a patient of a vascular arteriovenous graft (46), wherein the vascular arteriovenous graft includes a cannulation chamber (140) and has a proximal end and a distal end and a length extending along a longitudinal axis between the proximal end and the distal end, and wherein the apparatus is configured for use with a rigid tunneling instrument (42) for forming a subcutaneous anatomical tunnel, the rigid tunnelling instrument (42) including an elongated shaft (48) having a handle (50) at a proximal end of the shaft (48) and a removable tip (52) at a distal end of the shaft (48) for creating a pathway in the subcutaneous tissue, the subcutaneous delivery apparatus (40) comprising: an elongated tubular sleeve (44) having a length and defining an interior lumen, the sleeve (44) adapted for being slidably positioned over at least a portion of the shaft (48) of the tunneling instrument (42) between the handle (50) and the tip (52) such that in use, once the tunneling instrument (42) has been advanced to a desired subcutaneous anatomical location, the shaft (48) is configured to be selectively removed from the sleeve (44) while the sleeve (44) is configured to remain positioned at the desired anatomical location, the sleeve (44) having a slit (58) extending along the length of the sleeve (44) from a proximal end (54) of the sleeve (44) to a point intermediate the length of the sleeve (44), wherein the sleeve (44) is uniformly tapered from the proximal end (54) to a distal end (56) such that the distal end (56) has a reduced diameter from the proximal end (54), wherein the lumen defined at the proximal end (54) of the sleeve (44) is adapted to receive the distal end of the graft (46) and at least a portion of the cannulation chamber (140) such that a proximal end portion (54) of the sleeve (44) is configured to progressively expand along the slit (58) to provide an enlarged diameter for accommodating the cannulation chamber (140), and wherein, in use, the application of a longitudinal force to the sleeve (44) from the distal end (56) of the sleeve (44) is effective to cause the sleeve (44) to move in a distal direction during removal of the sleeve (44) from the tissue such that the graft (46) is fixed in the sleeve (44) by radial compression of the sleeve (44) for pulling the graft (46) and the sleeve (44) through the tunnel for deploying the vascular graft (46).
2. The subcutaneous delivery apparatus as recited in claim 1, wherein the sleeve (44) is adapted to receive substantially the entire length of the shaft (48) between the handle (50) and the tip (52).
3. The subcutaneous delivery apparatus as recited in claim 1, wherein the slit (58) is linear.
4. The subcutaneous delivery apparatus as recited in claim 1, wherein the sleeve (44) comprises an enlarged diameter portion adjacent the proximal end (54), the enlarged diameter portion of the sleeve (44) adapted for receiving the cannulation chamber (140).

Description

Cross-References to Related Applications This application claims the benefit of U.S. Provisional Application No. 63/166,794 and U.S. Provisional Application No. 63/166,790, both filed March 26, 2021. Background An apparatus and method are described for implanting an arteriovenous graft and, more particularly, an apparatus and method for using a tunneling instrument in forming a subcutaneous anatomical tunnel for implanting the arteriovenous graft, including use of a removable sleeve enclosing the tunneling instrument for delivery of the graft. A vascular arteriovenous graft is a tubular device that is suitable for implantation in the body to redirect flow of blood between blood vessels. Surgical implantation of the arteriovenous graft requires placement of the graft within subcutaneous tissue. An initial step in the implantation procedure is creation of a subcutaneous anatomic pathway, or "tunnel", for passage of the arteriovenous graft, which is commonly called a graft tunnel, between anastomotic sites. This is a required surgical step in peripheral vascular procedures for all peripheral, vascular access and extra-anatomical graft locations. The arteriovenous graft is positioned in the tunnel within the bodily tissue for fixation of the graft to an existing peripheral vessel to form a bypass around the vessel, or a portion thereof, or connection of an artery and vein to form an arteriovenous shunt. The vascular graft may also connect an artery to an artery. A conventional tunneling device includes an elongated rigid rod having a handle on a proximal end and a bullet-shaped tip at a distal end. The rod may vary in size and shape and may have a straight shaft, a curved shaft or a semicircular shaft, which allows for a variety of graft placement positions and locations. In the tunneling procedure, a first proximal incision and a second distal incision are made at a chosen area of anastomosis. The tip at the distal end of the tunneling device is inserted into the proximal incision. The tip of the tunneling device is then forcefully passed through the subcutaneous tissue creating a path between the incisions by blunt dissection until the tip protrudes from the distal incision. Once the tip is exposed, a proximal end of the arteriovenous graft is tied onto the distal end or the tip of the tunneling device with sterile suture thread. The tunneling instrument and attached arteriovenous graft are then pulled proximally along the path through the recently dissected graft tunnel until the proximal end of the arteriovenous graft extends from the proximal incision. When the arteriovenous graft is appropriately positioned, the graft is cut free from the distal end of the tunneling instrument, removing a portion of the graft. An anastomosis is formed between the ends of the graft and the blood vessels around the area of vasculature to be bypassed and the incisions are closed. The step of pulling the tunneling instrument and attached arteriovenous graft through the graft tunnel can require significant force. The force required depends on a number of 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 by a retaining sleeve that reduces the friction of passage through the subcutaneous tissue. Following implantation, the sleeve is removed by pulling or rolling back over the device to retract the sleeve. While rolling a sleeve during retraction reduces the necessary pulling force as compared to withdrawing the sleeve by sliding the sleeve over the device, there still can be significant force necessary to retract a sleeve following implantation of an arteriovenous graft. US2005/192604A1 describes devices and methods for placing a conduit in fluid communication with a target vessel to communicate the target vessel with a source of blood. A conduit is coupled to the target vessel by first and second securing components that compress or sandwich the vessel wall. US2020/197205A1 describes an apparatus for subcutaneous implantation in a patient using a tunneling instrument. The implantation apparatus comprises a vascular graft and a connector adapted to couple a distal end of the tunneling instrument and a proximal end of the graft. US2005/203457A1 describes a kit apparatus and a methodology to prevent the primary causes of arterio-venous graft thrombosis; and provides a durable vascular access for successful long term use in hemodialysis. The invention employs a patient-customized prosthetic endograft as an subcutaneously implanted vascular access. US2006/173467A1 describes a tunneling device for implanting a natural tissue vascular graft in a body. The tunneling device may include a flexible sheath to assist in locating the vascular graft in the body. US2003/125789A1 describes devices, systems, and methods for positioning an article, such as a graft or catheter, in a subcuta