This invention relates to systems for delivering a medical device, such as a stent, to a body location.
Medical devices that are deployed at a site inside the body must be delivered to the site. For example, stents are cylindrical devices used to maintain the patency of a body passageway, such as a blood vessel or a urethra. A stent is delivered to the location where it is to be deployed on the distal end of a delivery device such as a catheter. During delivery, the stent is maintained in a small caliber conformation. After delivery to the site of deployment, the stent is made or allowed to expand so as to assume a large caliber conformation in the body passageway. Some stents are “self-expanding”, in which case the stent in the large caliber conformation is mechanically restrained in the small caliber conformation in which it is delivered to the site of deployment. After delivery, the restraint is removed so as to allow the stent to assume its large caliber conformation at the site of deployment. It is also known to form a stent from a one-way or two-way shape memory alloy, such as Nitinol™. With this type of stent, the stent is brought from one caliber to another by exposing the stent to a change of temperature, as is known in the art of shape memory stents. Balloon expandable stents, made of a non-shape memory material such as stainless steel, are also known.
U.S. Pat. Nos. 6,221,081 and 6,517,569 to Mikus et al disclose an insertion device in which a stent is mounted onto the distal end of an inner sheath. The stent is surrounded by a “peel-away sheath”, which in turn is surrounded by an outer sheath. After the distal end of the device has been delivered to a body site where the stent is to be deployed, the outer sheath is retracted. The stent is then allowed to assume its large caliber conformation. The “peel-away sheath” is then grasped and manually split by the user as the “peel-away sheath” is removed.
U.S. Pat. No. 6,159,198 to Gardeski et al. discloses an introducing system for introducing electric leads to a body site. The introducer has a hollow sheath through which the leads are delivered to a body site. After the leads have been delivered, the sheath is manually retracted from the body. As the sheath is pulled out of the body it encounters a blade that cuts the sheath longitudinally from its proximal end to its distal end.
In its first aspect, the present invention provides a delivery system for delivering a stent to a body site. The stent delivery system of the invention has a grasping handle from which extends a slender hollow sheath. The tube has a diameter configured to allow a stent to be mounted onto the tube in its small caliber conformation. The tube is contained in the lumen of a cylindrical sheath formed from a soft pliant material such as Teflon, so that a stent mounted on the tube is covered by the sheath.
Within the grasping handle is an actuating mechanism, for causing proximal movement of the sheath over the tube so as to expose a stent mounted on the distal end of the sheath. As the sheath slides proximally under the influence of the actuating mechanism, the proximal end of the sheath encounters one or more blades. The blades are positioned in the grasping handle so as to slit the sheath longitudinally from its proximal end to its distal end as the sheath slides proximally over the sheath. The cut portion may accumulate inside a compartment or may exit the grasping handle.
In one embodiment of the invention, the actuating mechanism includes a trigger and one or more friction clamps. The friction clamps are coupled to the trigger so that, when the trigger is depressed, the friction clamps firmly grasp the sheath and cause the sheath to be displaced proximally over the tube. The trigger is spring biased in its released position. When the trigger subsequently returns to its released position, the friction clamps assume a non-engaging configuration in which the sheath is released from the grasp of the friction clamps so as to prevent movement of the sheath over the tube. Repeated cycles of depressing and releasing the trigger therefore cause a cumulative proximal sliding of the sheath along the tube and into the blades.
In its second aspect, the invention provides a method for delivering a stent to a body location. In accordance with this aspect of the invention, a stent in its small caliber conformation is mounted onto the distal end of the tube of the delivery system of the invention. The tube and stent are then covered with the sheath of the delivery system. The distal end of the sheath is then delivered to a body site where the stent is to be deployed. The actuating mechanism is then used to cause proximal movement of the sheath over the tube. As the sheath moves proximally over the tube, the tube is engaged by the blades which slit the tube from its proximal end to its distal end. The proximal movement of the tube, and the slitting of the tube by the blades, continue until the distal end of the tube has completely slid over the stent and the stent is no longer covered by the tube. The stent is then allowed to assume its large caliber configuration in which it is to be deployed in the passageway. After deployment of the stent, the tube is removed from the body.
Thus, in its first aspect, the invention provides a system for delivering a medical device to a body location, comprising:
In its second aspect, the invention provides a method for delivering a medical device to a body location; comprising:
In order to understand the invention and to see how it may be carried out in practice, a preferred embodiment will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
The delivery system 2 has a grasping handle 4. A slender hollow sheath 6, having a proximal end 8, initially located inside the grasping handle 4, and a distal end 10, has an inner diameter configured to allow the stent 18 in its small caliber conformation or another medical device to be contained inside the distal end of the sheath 6. The proximal end 8 of the sheath is mounted on a rigid or flexible tube 5 located in, and extending from, the grasping handle 4. In the lumen of the sheath 6, between the tip of the tube 5 and the medical device 18 is a spacing rod 20 having an axial channel 7. The tube 5 is provided with a first fitting 12 for connection to a fluid source such as water or saline, for delivering the fluid to the distal end of the sheath 6 via the lumen of the tube 5 and the channel 7. The tube 5 is also provided with a second fitting 14 for attachment to an optical element (not shown) for viewing a body region in the vicinity of the distal end 10. Within the housing of the grasping handle 4, is an actuating mechanism, generally indicated by 16, for retracting the sheath 6 proximally so as to uncover the medical device 18, as explained in detail below.
The sheath 6 is formed from a soft pliant material such as Teflon or polycarbonate. In the case that the medical device 18 is a self-expanding stent, the sheath 6 may serve to restrain the stent in its narrow caliber configuration until it is to be deployed in the body. The insert to
When the medical device 18 has been delivered to a body location where it is to be deployed, the actuating mechanism 16 is used to retract the sheath 6 in a proximal direction so as to expose the medical device 18. The actuating mechanism 16 includes a trigger 24 that is slidable along a track 26 from a released position shown in
The friction clamp 28 is attached to the trigger 24 so that as the trigger 24 is depressed from its released position shown in
As stated above the sheath 6 is made from a soft pliant material such as Teflon. As the sheath 6 slides proximally under the influence of the actuating mechanism 26, the proximal end 8 of the sheath 6 encounters one or more blades 41. The blades 41 are positioned in the grasping handle 4 so as to slit the sheath 6 longitudinally. The slit portion 42 of the sheath 6 splays apart allowing the slit portion 42 to pass around the fittings 12 and 14. The slit portion 42 may exit the grasping handle 4, as shown in
The delivery system 42 has a grasping handle 44. A slender hollow sheath 46, having a proximal end 38 has an inner diameter configured to allow the medical device 18, such as a stent in its small caliber conformation or another medical device, to be contained inside the distal end of the sheath 46. In the case that the medical device 18 is a self-expanding stent, the sheath 46 may serve to restrain the stent in its narrow caliber configuration until it is to be deployed in the body. The sheath 46 is inserted over a tube 45 extending from the grasping handle 44, and is pushed towards one or more blades 72. In the lumen of the sheath 36, between the tip of the tube 35 and the medical device 18 is a spacing rod 50 having an axial channel 37. The tube 45 may be provided with a first fitting 43 for connection to a fluid source such as water or saline, for delivering the fluid to the distal end of the sheath 36 via the lumen of the tube 35 and the channel 37. The rigid tube 35 may also be provided with a second fitting 47 for attachment to an optical element (not shown) for viewing a body region in the vicinity of the distal end 40.
Within the housing of the grasping handle 44, is an actuating mechanism, generally indicated by 56, for retracting the sheath 46 proximally so as to uncover the medical device 18, as explained in detail below.
When the medical device 18 has been delivered to a body location where it is to be deployed, the actuating mechanism 56 is used to retract the sheath 36 in a proximal direction so as to expose the medical device 18. The actuating mechanism 56 includes a trigger 54 that is slidable along a track 57 from a released position shown in
The trigger 54 is attached to a gear rack 59. As the trigger 54 is moved proximally, it causes the gear 66 to rotate clockwise in the perspective of
The trigger 54 is spring biased in its released position by a spring not seen in the perspective of
The proximal movement of the sheath 46 and the slitting of the proximal end of the sheath by the blades 72 continue until the sheath 46 has completely slid proximally over the medical device 18 so that the medical device 18 is no longer covered by the sheath 46 The medical device may then be deployed. For example, if the medical device 18 is a stent, the stent is deployed by being brought to its large caliber conformation. After deployment of the medical device 18, the sheath 6 is removed from the body.
Number | Date | Country | Kind |
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170698 | Sep 2005 | IL | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IL2006/001029 | 9/6/2006 | WO | 00 | 6/26/2008 |
Publishing Document | Publishing Date | Country | Kind |
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WO2007/029242 | 3/15/2007 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5261887 | Walker | Nov 1993 | A |
5529225 | Chang | Jun 1996 | A |
5868755 | Kanner et al. | Feb 1999 | A |
5944727 | Ahari et al. | Aug 1999 | A |
6159198 | Gardeski et al. | Dec 2000 | A |
6221081 | Mikus et al. | Apr 2001 | B1 |
6391051 | Sullivan et al. | May 2002 | B2 |
6517569 | Mikus et al. | Feb 2003 | B2 |
6599296 | Gillick et al. | Jul 2003 | B1 |
7326203 | Papineau et al. | Feb 2008 | B2 |
20020123755 | Lowe et al. | Sep 2002 | A1 |
20020165554 | Dworschak et al. | Nov 2002 | A1 |
Number | Date | Country |
---|---|---|
9820812 | May 1998 | WO |
03074120 | Sep 2003 | WO |
2004066809 | Aug 2004 | WO |
Number | Date | Country | |
---|---|---|---|
20080319524 A1 | Dec 2008 | US |