Deflection control catheters, support catheters and methods of use
A deflection and support catheter provided for improved manipulation of elongated medical devices used during percutaneous procedures in difficult to reach situations. In particular, the deflection and support catheters can facilitate placement of guidewires, guide catheters, and intervention devices such as angioplasty balloons and stent delivery devices.
This application claims priority to copending provisional patent application Ser. No. 60/762,304 filed on Jan. 26, 2006 to Webster et al., entitled “Deflection Control Catheter and Related Method of Use,” incorporated herein by reference.
FIELD OF THE INVENTIONThe invention relates to catheters to facilitate the delivery of guidewires, guide catheters or other interventional devices within a branched vascular network. The invention further relates to methods for the delivery of guidewires, guide catheters or other interventional devices along branched vessels in a body.
BACKGROUND OF THE INVENTIONPercutaneous vascular procedures are performed in many vessels in the body, including, for example, the coronary arteries, saphenous vein grafts, carotid arteries, cerebral vessels, and peripheral vessels. These procedures generally require the physician to gain access to the target vessel with a guiding catheter or sheath and track a guidewire into the vessel past a lesion or other location for the performance of a treatment procedure. One common complication of percutaneous procedures is the inability to gain access to a vessel and thus to properly position the interventional devices past the target position. Anatomical variations, such as lesion size and morphology, vessel tortuosity, and vessel take off angle contribute to these complications. Additional factors, such as poor guide support, can further lead to crossing issues. These complications can be compounded when the patient has previously received a stent, when the target lesion is located at a bifurcation, or when the patient has a chronic total occlusion where the vessel is completely or almost completely blocked.
SUMMARY OF THE INVENTIONIn a first aspect, the invention pertains to a catheter comprising a proximal segment and a rapid exchange segment connected at or near the distal end of the proximal segment. The rapid exchange segment comprises a tubular element with a lumen having a slit structure and sufficient rigidity to track over a cylindrical object within the lumen by pushing from the proximal end of the proximal segment.
In a further aspect, the invention pertains to a medical delivery tool for elongated medical devices. The tool comprises a flexible rod and a tubular element operably connected to the rod. The tubular element has a distal opening, a proximal opening and an open lumen connecting the distal opening and the proximal opening such that the tubular element forms a rapid exchange element to fit over an elongated medical device. In some embodiments, the tubular element has a side port.
In another aspect, the invention pertains to a method for the delivery of an elongated medical device into a vessel within a vascular network. The method comprises loading a rapid exchange segment of a delivery tool onto the elongated medical device and using the delivery tool to provide support for the placement of the elongated medical device into the vessel. The rapid exchange segment generally comprises a slit that provides for the loading of the rapid exchange segment.
In other aspects, the invention pertains to a method for the delivery of a guidewire into a vessel within a vascular network. The method comprises extending a curve tip of the guidewire through a side port of a deflection catheter into the vessel in which the side port is positioned at the opening into the vessel.
Moreover, the invention pertains to a catheter comprising a proximal section, and a rapid exchange segment operably connected to the proximal section. The rapid exchange segment comprises a tubular element having a guide lumen, a tip, a distal guide port and a side guide port, and the tubular element has a curve in the tip.
Furthermore, the invention pertains to a guidewire delivery system comprising a guidewire having a curved tip and a deflection catheter comprising a proximal section and a rapid exchange segment operably connected to the proximal section. The rapid exchange segment comprising a tubular element comprising a guide lumen, a distal guide port at the distal end of the guide lumen and a proximal guide port.
BRIEF DESCRIPTION OF THE DRAWINGS
A deflection and support catheter as described herein provides assistance to direct an elongate member within a blood vessel during a percutaneous procedure into a difficult to reach branch vessel. The deflection and support catheter can provide both direction and support for entering into a difficult branch vessel to navigate. In some embodiments, the deflection and support catheter has a side port at a stiffened section to provide support while the elongate member is directed through the side port into a difficult to reach vessel. In appropriate embodiments, once the side port is properly positioned, the curved tip of the elongate member, such as a guidewire, facilitates the entry of the elongate member out from the side port into the difficult to reach vessel. With the support from a deflection and support catheter, the physician can manipulate a guidewire past difficult to reach positions in the branch vessel, such as past thrombus accumulated at or near the vessel opening. Once the guidewire is in position, the deflection and support catheter can be removed, and the guidewire can be used to guide treatment structures, such as angioplasty balloons and stents into the branch vessel. In other embodiments, support and increased manipulation can be provided for the guiding catheter or sheath with a deflection and support catheter that similarly provides support for the distal end of a guide catheter. Interaction between the curve of the guiding catheter and the deflection and support catheter can aid in steering and push. In this embodiment, the support catheter generally has a rapid exchange segment that can clip over a guide catheter. In a further embodiment, the deflection and support catheter can be configured to ride over the shaft of an interventional device such as a balloon or stent system. The deflection and support catheter can provide increased support to the distal segment of the interventional device that extends out the distal end of the guiding catheter or sheath.
The deflection catheters described herein are generally useful for the placement of guidewires or catheters in difficult to reach vessels within the body of a patient, generally a human, although the device can be used in other mammals. Similarly, the deflection and support catheters are useful to facilitate the deployment of guide catheters. Once the guidewire/guide catheter/interventional device is placed at the desired location, the deflection/support catheter is generally removed. In some embodiments, the treatment structure or medical instrument is placed at or past a lesion, which can be thrombus within in the vessel.
The deflection and support catheter can have an over the wire or rapid exchange configuration. In a rapid exchange configuration, the elongate member extends within only a portion of the catheter. The catheter generally has a guide port at its distal tip. For rapid exchange embodiments, a rapid exchange guide port is located to define a guide lumen extending from the rapid exchange guide port to the distal port. The side port is located at an appropriate position between the rapid exchange port and the distal port. For embodiments that support and deflect other interventional devices down difficult vasculature, the catheter has an overall length to reach the target vessel from an appropriate insertion point into the patient. For embodiments that support and deflect other interventional devices, the catheter has an overall length to reach the distal end of the interventional device.
In the rapid exchange configuration, the proximal portion of the catheter extending in a proximal direction from the rapid exchange port can be solid or tubular while providing a desired degree of strength and flexibility since this section of catheter only provides a mechanical function. In particular, the proximal portion of the catheter can have a rod structure, a tubular structure or other similar elongated form, with a flat, circular or other appropriate cross section shape. The proximal section is used only advance, withdraw and steer the rapid exchange segment within the vessel from a section that is exterior to the patient. Thus, this proximal segment should be stiff enough to push the rapid exchange segment, and it should transmit torque for steering. However, this proximal segment generally does not need an open lumen or an outer surface suitable for the passage of instruments. Also, it is advantageous for this segment to be of low profile.
In some embodiments, the deflection and support catheter has a side port that is configured to facilitate the guiding of an elongate member, such as a guidewire, out from the side port. The side-guide port should be configured to allow for relatively easy passage of a tip, generally a curved, tip of a guidewire to exit the side port. For some embodiments, the widest diameter across the port opening in some embodiments is at least 1.5 times the size of the guidewire diameter and in other embodiments at least twice the size of the guidewire diameter. The guide catheter can then support the movement of the guidewire into a branch vessel even past an occlusion while not making the task of the health care provider excessively difficult. Generally, the side guide port does not have a tubular projection so that there is no extraneous structure to snag while moving the structure within a vessel. However, the side port can be reinforced. In general, there is no projection of a millimeter or greater from the side port relative to the surface of the catheter.
In some embodiments, the deflection and support catheter has curves at its tip for either an over the wire or rapid exchange configuration. The curve can assist with placement of the side port adjacent to an opening into a side branch vessel. The catheter can have one or more curves along the length. It can be advantageous to have two, three or more curves.
To provide additional support and to reduce or eliminate kinking, it can be desirous to have a stiffened section at or near the side port. Thus, the section surrounding the side port can be stiffer than proximal and distal segments. Alternatively or additionally, the section around the port can be stiff relative to other sections of the catheter. The stiffness can be provided by coating or embedding a wire or reinforcement at the appropriate section and/or by using a different material welded or otherwise connected to adjacent material. Furthermore, the side port section can be constructed with one or more radiopaque bands that aid in visualization and also provide increased stiffness. In some embodiments, the stiffened section has a stiff measured with a Durometer value of at least about 60 D.
In alternative embodiments, the deflection and support catheter has a bent tip with appropriate stiffness so that a guidewire or catheter extending outward from the tip can hold the tip straight if extending sufficient from the tip, or the tip can bend if the guidewire/catheter is extending only a short distance from the tip. This embodiment provides an alternative to embodiments with a side port.
To use the deflection and support catheter for delivery of a guidewire into a branch vessel, the guidewire is directed into the main vessel past the branch point. The deflection catheter can be delivered over the guidewire while the guidewire is being delivered or after the guidewire is in place. Then, the deflection catheter is positioned with the side port adjacent the opening into the branch vessel. Placement can be facilitated using radiopaque markers on the deflection catheter or through visualization of radiopaque material forming at least along a portion of the deflection catheter, along with visualization dye in the vessel if desired. Once the deflection catheter is in place, the guidewire can be retracted so that its tip can exit through the side port. With the support of the deflection catheter the guidewire generally can be positioned past a lesion at or near the opening of the branch vessel. Similarly, the support of the deflection catheter can be used to reach into sharp bending branch vessels that are otherwise difficult or impossible to reach. Once the guidewire is in place, the deflection catheter can be removed. Thus, the deflection catheter provides for the performance of procedures that would not be otherwise possible.
In an alternative embodiment, the support catheter is used to support another interventional device such as a balloon or stent deploying instrument. This embodiment is referred to as a support catheter. The support catheter generally has a rapid exchange configuration. The tubular element of the support catheter has an inner lumen sufficiently large for the passage of a guide catheter of a selected diameter. A proximal section extends proximally from the rapid exchange segment. This proximal section should have enough stiffness to advance and withdraw the support catheter onto and off from the guide catheter. The rapid exchange segment has a slit structure that provides for loading and unloading the rapid exchange segment onto and off from the guide catheter or interventional device since the guide catheter or other interventional device generally has handles and other structures attached to its proximal end that makes it difficult or impossible to advance the support catheter over the end of the guide catheter. A slit refers broadly to any structure that provide for opening of the generally cylindrical lumen to extend the rapid exchange segment around the guide catheter. For example, the slit can have overlapping portions, locking portions or the like, and some representative embodiments are described further below.
Support catheter can be placed over the guide catheter or other elongated interventional device for placement into a vessel. The support catheter can be inserted into the patient if the health care professional is having difficulty placing a guide catheter at a desired location. The support catheter can provide additional support at the distal end of the guide catheter to facilitate placement of the guide catheter. Once the guide catheter is in place, the support catheter can be removed.
The advantages of the deflection catheter and support catheter can be further elucidated from the specific embodiments described in the following.
Deflection/Support Catheter Structure
The deflection/support catheter has a distal port as well as a side port and/or a proximal rapid exchange port. In embodiments of particular interest, the catheter has a rapid exchange segment with a rapid exchange port with the rapid exchange segment designed to ride over a medical device during a percutaneous procedure. In some embodiments, the rapid exchange segment can have a slit to provide easier placement over the medical device for loading. In additional or alternative embodiments, the deflection and support catheter has a curved tip and/or a curved distal portion. A side port, if present, can be configured to provide exit of the tip of the elongated medical device directed with the deflection/support catheter. The deflection/support catheter can be formed from a radiopaque material and/or can have one or more radiopaque marker bands to facilitate proper positioning in a patient.
A medical device delivery system comprises an elongated medical device and a deflection and support catheter that is designed to ride over the elongated medical device in an over the wire or rapid exchange configuration. Referring to
Percutaneous tools with rapid exchange, or monorail, segments can be desirable due to their ease of loading. Referring to
A particular embodiment of the medical delivery tool as a rapid exchange deflection/support catheter is shown in
An expanded, fragmentary sectional view of rapid exchange segment 154 is shown in
Referring to
An alternative embodiment of a rapid exchange segment for a deflection and support catheter is shown in
Referring to
The deflection and support catheter can have curves that deflect the side port away from the axis of the distal and proximal ports. Two embodiments with curved rapid exchange segments are shown in
Referring to
A two wire embodiment is depicted in
A deflection and support catheter with a distal bent tip is shown in
Another embodiment of a deflection and support catheter is shown in
An embodiment of a support catheter is shown in
Referring to
In one specific embodiment for use in coronary arteries, connecting rod 354 can have a length of roughly 95 centimeters, and rapid exchange segment 356 can have a length of roughly 15 centimeters. Rapid exchange segment can have an inner diameter to fit over a 4 to 4.5 French catheter and an outer diameter to just fit within a 6 F guide catheter. For other applications, a person of ordinary skill in the art can adjust the dimensions of the device appropriately based on the teachings herein.
In general, the deflection/support catheter can be formed from one or more biocompatible materials, including, for example, metals, such as stainless steel or alloys, e.g., Nitinol®, or polymers such as polyether-amide block co-polymer (PEBAX®), nylon (polyamides), polyolefins, polytetrafluoroethylene, polyesters, polyurethanes, polycarbonates or other suitable biocompatible polymers. Radiopacity can be achieved with the addition of markers, such as platinum-iridium or platinum-tungsten or through radio-pacifiers, such as barium sulfate, bismuth trioxide, bismuth subcarbonate, powdered tungsten, powdered tantalum or the like, added to a polymer resin. Generally, different sections of deflection/aspiration catheter can be formed from different materials from other sections, and sections of the catheter can comprise a plurality of materials at different locations and/or at a particular location. For example, a proximal extended rod/wire can be formed from metal, such as stainless steel. With respect to a rapid exchange segment, one material of particular interest is a themoplastic polymer with embedded metal wire. Suitable polymers include, for example, polyamides, i.e., nylons. The wire can be braided, coiled or otherwise placed over a polymer tubing liner with some tension. A polymer jacket is then placed over the top. Upon heating over the softening temperature of the polymer and subsequent cooling, the wire becomes embedded within the polymer. The liner and jacket can be the same or different materials. Suitable wire for embedding in the polymer includes, for example, flat stainless steel wire. The wire adds additional mechanical strength while maintaining appropriate amounts of flexibility.
The materials generally can be molded, extruded or the like, for example, based on well known processing approaches in the field. Materials can be joined by softening one material and embedding the other material within the softened material, and/or using mechanical reinforcements, clams, brackets or the like. Medical grade materials are generally commercially available for adaptation for forming the structures described herein. Curves can be introduced to polymer material through softening the polymer and hardening the polymer on a curved mandrel or the like.
Use of the Devices
In general, the deflection/support catheters can be used in any reasonable vessels in a patient. However, the deflection/support catheters are particularly useful for directing medical instruments in a patient's blood vessels. In general, the deflection/support catheters are intended to facilitate procedures so that they are easier and faster than difficult procedures using other instruments. Furthermore, the deflection/support catheters are intended to facilitate procedures that otherwise could not be completed since the medical instruments could not be positioned appropriately.
A general application of a deflection and support catheter is depicted in
Referring to
Referring to
Referring to
The use of a support catheter generally is depicted in
Based on a rough estimate, 10 to 20 percent of procedures have significant difficulty reaching or crossing a lesion with a treatment structure due to proximal vessel tortuosity, calcification and/or the like. The approaches described herein using a support catheter are more generally applicable and are expected to have a greater degree of success relative to approaches based on exchanging devices for a smaller balloon, changing the guide catheter, using a buddy guidewire or the like.
The deflection/support catheters can be sterilized and packaged for distribution using, for example, conventional approaches. Radiation and or chemical sterilization can be used. The packaged catheters can be distributed for use with other medical devices for percutaneous procedures.
The embodiments above are intended to be illustrative and not limiting. Additional embodiments are within the claims. In addition, although the present invention has been described with reference to particular embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention. Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein.
Claims
1. A catheter comprising a proximal segment and a rapid exchange segment connected at or near the distal end of the proximal segment, the rapid exchange segment comprising a tubular element with a lumen having a slit structure and sufficient rigidity to track over a cylindrical object within the lumen by pushing from the proximal end of the proximal segment.
2. The catheter of claim 1 wherein the proximal segment comprises a rod.
3. The catheter of claim 2 wherein the rod is solid.
4. The catheter of claim 1 wherein the slit comprises overlapping lips.
5. The catheter of claim 1 wherein the slit has a spiral configuration.
6. The catheter of claim 1 wherein the rapid exchange segment further comprises an overtube that slides over the tubular element with the slit structure.
7. The catheter of claim 1 wherein the tubular element comprises a radiopaque marker band.
8. The catheter of claim 1 wherein the tubular element comprises a radiopaque-loaded polymer.
9. A medical delivery tool for elongated medical devices, the tool comprising a flexible rod and a tubular element operably connected to the rod wherein the tubular element has a distal opening, a proximal opening and an open lumen connecting the distal opening and the proximal opening such that the tubular element forms a rapid exchange element to fit over an elongated medical device, wherein the tubular element has a side port.
10. The medical delivery tool of claim 9 wherein the side port has an elongated shape with a length along the longitudinal direction of the catheter that is at least about 2 times the average diameter of the guide lumen.
11. The medical delivery tool of claim 9 wherein the tubular element has a durometer value of at least about 60 D at the side guide port.
12. The medical delivery tool of claim 9 wherein the tubular element has a slit.
13. The medical delivery tool of claim 9 wherein the tubular element is curved.
14. A method for the delivery of an elongated medical device into a vessel within a vascular network, the method comprising loading a rapid exchange segment of a delivery tool onto the elongated medical device and using the delivery tool to provide support for the placement of the elongated medical device into the vessel wherein the rapid exchange segment comprises a slit that provides for the loading of the rapid exchange segment.
15. The method of claim 14, wherein the elongated medical device comprise a balloon or a stent delivery structure.
16. A method for the delivery of a guidewire into a vessel within a vascular network, the method comprising extending a curve tip of the guidewire through a side port of a deflection catheter into the vessel wherein the side port is positioned at the opening into the vessel.
17. The method of claim 16 wherein the vessel is a coronary artery.
18. A catheter comprising a proximal section, and a rapid exchange segment operably connected to the proximal section, the rapid exchange segment comprising a tubular element having a guide lumen, a tip, a distal guide port and a side guide port, the tubular element having a curve in the tip.
19. A guidewire delivery system comprising a guidewire having a curved tip and a deflection catheter comprising a proximal section and a rapid exchange segment operably connected to the proximal section, the rapid exchange segment comprising a tubular element comprising a guide lumen, a distal guide port at the distal end of the guide lumen and a proximal guide port.
20. The guidewire delivery system of claim 19 wherein the rapid exchange segment comprises a side guide port.
21. The guidewire delivery system of claim 19 wherein the rapid exchange segment has a bent tip.
22. The guidewire delivery system of claim 19 wherein the rapid exchange segment is curved.
23. The guidewire delivery system of claim 19 wherein the rapid exchange segment has a plurality of curves.
24. The guidewire delivery system of claim 19 wherein the tubular element comprises a proximal tubular segment, a distal tubular segment and a non-tubular connection element connecting the proximal tubular segment and the distal tubular segment, wherein the side port is formed by the opening at the non-tubular connection element.
Type: Application
Filed: Jan 25, 2007
Publication Date: Sep 6, 2007
Inventors: Mark Webster (Mt. Eden), Jason Galdonik (Hanover, MN)
Application Number: 11/698,248
International Classification: A61M 29/00 (20060101); A61M 31/00 (20060101); A61M 37/00 (20060101);