The invention generally relates to stent devices for maintaining the patency of the biliary tree, or common bile duct and methods for introducing stent devices.
Strictures or occlusions that develop in the upper common bile duct and/or the left and right hepatic ducts can interfere with the proper drainage of those ducts.
Consequently, there is a need for a self-expanding stent delivery system which overcomes the problems associated with prior art delivery systems. Specifically, there is a need for a self-expanding stent delivery system which allows the physician to simultaneously place a first and second stent in the side branches and main lumen of a bifurcation.
In one aspect of the invention, the stent delivery system includes a first introducer, a second introducer and an endoscope having a working channel. The first and second introducers are adapted to be disposed in an adjacent configuration within the working channel of the endoscope. The first introducer comprises a first outer catheter and a first inner shaft having a first stent retaining area located on a distal portion of the first inner shaft. The first inner shaft is located coaxially within the first outer catheter. The first outer catheter includes a first proximal outer catheter having a first proximal outer diameter and a first distal outer catheter having a first distal outer diameter. The distal end of the first proximal outer catheter is attached to a proximal end of the first distal outer catheter and the first proximal outer diameter is less than the first distal outer diameter.
The second introducer comprises a second outer catheter and a second inner shaft having a second stent retaining area located on a distal portion of the second inner shaft. The second inner shaft is located coaxially within the second outer catheter. The second outer catheter includes a second proximal outer catheter having a second proximal outer diameter and a second distal outer catheter having a second distal outer diameter. The distal end of the second proximal outer catheter is attached to a proximal end of the second distal outer catheter and the second proximal outer diameter is less than the second distal outer diameter.
In a second aspect of the invention, the stent delivery system comprises a first introducer, a second introducer and an endoscope having a working channel. The first and second introducers are adapted to be disposed in an adjacent configuration within the working channel of the endoscope. The first introducer comprises a first outer catheter, a first inner shaft located coaxially within the first outer catheter, a stent retaining area located on a distal portion of the first inner shaft, a first stent tip attached to a distal end of the first inner shaft, a first pusher band located proximate the first stent retaining area, a first stent mounted on the first stent retaining area such that the first stent proximal end abuts the first pusher band, and a first wire guide lumen extending proximally from the first introducer distal end through at least a portion of the first introducer. The first outer catheter includes a first proximal outer catheter having a first proximal outer diameter and a first distal outer catheter having a first distal outer diameter.
The second introducer comprises a second outer catheter, a second inner shaft located coaxially within the second outer catheter, a stent retaining area located on a distal portion of the second inner shaft, a second stent tip attached to a distal end of the second inner shaft, a second pusher band located proximate the second stent retaining area, a second stent mounted on the second stent retaining area such that the second stent proximal end abuts the second pusher band, and a second wire guide lumen extending proximally from the second introducer distal end through at least a portion of the second introducer. The second outer catheter includes a second proximal outer catheter having a second proximal outer diameter and a second distal outer catheter having a second distal outer diameter.
The stent delivery system of the present invention may be configured such that the sum of the first proximal outer diameter and the second distal outer diameter is less than the inner diameter of the working channel of the endoscope. Alternatively, the stent delivery system of the present invention may be configured such that the sum of the first proximal outer diameter, the second distal outer diameter and at least one of a first and second wire guide diameters is less than the inner diameter of the working channel of the endoscope. As another alternative, the stent delivery system may be configured such that the first proximal outer diameter is disposed adjacent to the second distal outer diameter while inside the working channel of the endoscope.
In a fourth aspect of the invention, the method of placing a first stent within a first branch lumen and a main lumen of a bifurcation and placing a second stent within a second branch lumen and the main lumen of the bifurcation comprises the steps of: providing an endoscope having a first introducer with the first stent retained on a first distal portion and a second introducer having the second stent retained on a second distal portion disposed in an adjacent configuration within a working channel of the endoscope; placing a first wire guide into the main lumen and the first branch lumen of the bifurcation and placing a second wire guide into the second branch lumen and the second branch lumen of the bifurcation, and advancing the first introducer over the first wire guide into the main lumen and the first branch lumen of the bifurcation and advancing the second introducer over the second wire guide into the main lumen and second branch lumen of the bifurcation such that the first and second introducers are simultaneously positioned within the main lumen and the first and second branch lumens of the bifurcation. The method of the present invention may further comprise the step of: deploying, sequentially or simultaneously, the first stent within the first branch lumen and the main lumen of the bifurcation.
In a fifth aspect, the invention is a method of placing first and second stents in first and second branch lumens and a main lumen of a bifurcation comprising the steps of: positioning the first stent within the first branch and the main lumen of the bifurcation such that a distal portion of the first stent extends at least partially within the first branch of the bifurcation and a proximal portion of the first stent extends at least partially within the main lumen of the bifurcation; positioning the second stent within the second branch and the main lumen of the bifurcation such that a distal portion of the second stent extends at least partially within the second branch of the bifurcation and a proximal portion of the second stent extends at least partially within the main lumen of the bifurcation; and deploying the first and second stents within the bifurcation.
Referring now to the Figures wherein like numerals indicate the same element throughout the views, there is shown in
Referring now to
As shown in
Shaft 13, 23 has a proximal end 13a, 23a, a distal end 13b, 23b and a stent retaining area 15, 25. Optionally, shaft 13, 23 may include a pusher band 17, 27 attached to the stent retaining area 15, 25, a distal tip 18, 28 attached to the shaft distal end 13b, 23b and a wire guide lumen 19, 29. Shaft 13, 23 can be made from any suitable material known in the art including, but not limited to, polyethylene ether ketone (PEEK), polytetrafluoroethylene (PTFE), polyamide, polyurethane, polyethylene and nylon, including multi-layer or single layer structures and may also include reinforcement wires, braid wires, coils and or filaments. Preferably, shaft 13, 23 comprises a proximal portion made of a relatively rigid material such as stainless steel or any other suitable material known in the art.
Stent retaining area 15, 25 is preferably located on a distal portion of the shaft 13, 23. The stent retaining area 15, 25 retains a stent 16, 26 to be deployed in the bifurcation. Preferably, stent 16, 26 is a self-expanding stent.
Pusher band 17, 27 helps to prevent the stent from proximally migrating as the outer catheter 11, 21 is withdrawn proximally to deploy the stent. The pusher band 17, 27 is located proximal to the stent 16, 26 such that the proximal end of the stent 16, 26 abuts the pusher band 17, 27 as shown in
Distal tip 18, 28 helps prevent fluids from entering the outer catheter 11, 22 as the introducer 10, 20 is navigated through the body lumens. As shown in
In the embodiment shown in
Alternatively, the wire guide lumen 19, 29 may extend through the shaft 13, 23 from the shaft distal end 13b, 23b to the shaft proximal end 13a, 23a but the wire guide 32, 42 exits through an aperture positioned along the length of the introducer 10, 20. For example, as shown in
In the alternate embodiment shown in
In yet other alternative embodiments, the wire guide lumen 19, 29 may extend through a portion of shaft 13, 23 and may exit through an aperture 30, 40 positioned along the length of the introducer 10, 20. Any number of apertures 30, 40 positioned at any location along the length of the introducer 10, 20 is contemplated. In addition, the wire guide lumen 19, 29 may also comprise a channel or split.
Aperture 30, 40 provides the stent delivery system of the present invention with rapid-exchange capabilities. In particular, by extending the wire guide 32, 42 through only a distal portion of the wire guide lumen 19, 29, the delivery system can be removed from a wire guide 32, 42 having a length substantially shorter than the length necessary if the wire guide 32, 42 were extended through the entire length of the wire guide lumen 19, 29.
Referring to
In one embodiment, the proximal outer catheter 12, 22 and the distal outer catheter 14, 24 comprise separate catheters, or sheaths as shown in
Proximal outer catheter 12, 22 further comprises a proximal outer diameter and the distal outer catheter 14, 24 further comprises a distal outer diameter. In one embodiment the sum of the first outer catheter diameter and the second outer catheter diameter is less than the inner diameter of the working channel 8a of the endoscope 8.
Referring to the embodiment shown in
In yet another alternate embodiment of the stent delivery system 1 of the present invention, the pair of introducers 10, 20 may be sized to also accommodate a wire guide 32, 42 within the working channel 8A of the endoscope 8. For this embodiment, the sum of the outer diameter of the first proximal outer catheter 12, the outer diameter of the second distal outer catheter 24 and the diameter of at least one of the first and second wire guides 32, 42 is less than the inner diameter of the working channel 8a of the endoscope 8.
Preferably, the outer diameter of proximal outer catheter 12, 22 is about 5 to about 6 French and the outer diameter of the distal outer catheter 14, 24 is about 6 to about 7 French to place a stent 16, 26 having a compressed diameter of about 0.069 inches to about 0.077 inches. More preferably, the proximal outer catheter 12, 22 is about 5.5 French and the outer diameter of the distal outer catheter 14, 24 is about 6.5 French. These sizes are provided for illustrative purposes only and are not intended to be construed as a limitation of the present invention. As one of ordinary skill in the art would appreciate, the size of the introducer required to place a stent is related to the size of the stent to be placed, and more particularly, to the size of the compressed configuration of the stent. Thus, introducers 10, 20 having distal outer catheter diameters less than about 6 French used to place stents having compressed configurations less than about 0.069 inches that may become available in the future are contemplated as being within the scope of the claims of the invention.
Returning to
Preferably, proximal outer catheter 12, 22 further comprises a support portion 12d, 22d adjacent to the handle 33, 43 as shown in
Outer catheter, or sheath, 11, 21 can be made from any suitable material known in the art including, but not limited to, PTFE, polyamide, polyurethane, polyethylene and nylon including multi-layer or single layer structures and may also include reinforcement wires, braid wires, coils and or filaments. Preferably, at least the distal portion of outer catheter 11, 21 is made of any relatively clear material so that the stent 16, 26 mounted on the stent retaining area 15, 25 of the shaft 13, 23 can be viewed.
The stent delivery system 1 of the present invention is used to place first and second stents 16, 26 into a bifurcation having strictures 3 in the main lumen 2a and the first and second branch lumens 2b, 2c as follows. A distal end of a first wire guide 32 is advanced through the main lumen and into the first branch lumen of the bifurcation and a distal end of a second wire guide 42 is placed through the main lumen and into the second branch lumen of the bifurcation. The proximal ends of the first and second wire guides 32, 42 are passed through the accessory channel 8a of an endoscope 8. The first and second introducers 10, 20 are inserted into the working channel 8a of the endoscope 8. First and second introducers 10, 20 may be positioned side-by-side within the working channel 8a of the endoscope 8 as shown in the embodiment of
The above Figures and disclosure are intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in the art. All such variations and alternatives are intended to be encompassed within the scope of the attached claims. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the attached claims.