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.

FIELD OF THE INVENTION

The 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 INVENTION

Percutaneous 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.

BRIEF SUMMARY OF THE INVENTION

In 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.

DETAILED DESCRIPTION

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.

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 toFIG. 1, medical device delivery system100comprises an elongated medical device102and a medical delivery tool104, e.g., a deflection catheter/support catheter. The elongated medical device102can be a guidewire, guide catheter, balloon catheter, stent delivery catheter or other percutaneous medical instruments, such as those well known in the art. A shown inFIG. 1, elongated medical device102has a bent tip106. Guidewires as used herein can have a solid structure or an internal structures such as a hollow lumen or a core wire or the like. As shown inFIG. 1, medical delivery tool104has an optional side port108and an optional handle110.

Percutaneous tools with rapid exchange, or monorail, segments can be desirable due to their ease of loading. Referring toFIG. 2, Medical device delivery system116comprises an elongated medical device118and medical delivery tool120. Elongated medical device118can be the same medical devices described with respect to elongated medical device102. Medical delivery tool120has a rapid exchange segment122and a proximal extension124. Rapid exchange segment122comprises a distal port126and a proximal port128that provide for an elongated medical device to pass within the rapid exchange segment. As shown inFIG. 2, rapid exchange segment122has an optional side port130. Proximal extension124comprises an elongated element132and an optional handle134. Elongated element132can comprise a tubular element, a solid rod or other elongated segment. A solid, flexible rod or wire is convenient as having a smaller diameter than other structures for selected mechanical properties, and a smaller diameter provides for less blockage of the vessels and passage through smaller guide catheters during use. During use elongated element132connects rapid exchange segment122within the patient with the exterior of the patient.

A particular embodiment of the medical delivery tool as a rapid exchange deflection/support catheter is shown inFIG. 3. Deflection and support catheter150can be used to deflect a guidewire152into a branch vessel in a patient. Catheter150comprises rapid exchange segment154with side port156, rod158and handle160. In this embodiment, rapid exchange segment154has a radiopaque marker band162. For conventional guidewires, rapid exchange segment can have a 21/2 French diameter. As described further below, rapid exchange segment154can be formed from a polymer tube optionally with braided or wound metal wire embedded within the polymer.

An expanded, fragmentary sectional view of rapid exchange segment154is shown inFIG. 4. Side port156should have a size and shape to facilitate exit of the tip of guidewire152out through side port156. Thus, in some embodiments, the opening of side port156has a length along the longitudinal direction of the segment of at least about twice the diameter of guidewire152, and at least a portion of rapid exchange segment has a stiffness corresponding with a durometer value of 60 D to support guidewire152as it is pushed through side port156possibly into a significantly blocked branch vessel. As shown in the particular embodiment ofFIG. 4, the side port or window has a longitudinal dimension, L, of about 8 mm and a distal extension, D, of about 10 mm, although other dimensions are suitable as desired.

Referring toFIG. 6, rapid exchange segment154is shown with a single marker band170having a cylindrical configuration at the distal end of side port156. Referring toFIG. 6, rapid exchange segment154has a non-cylindrical marker band170that does not extend around the entire circumference of the rapid exchange segment. The non-circumferential marker may make it easier to align side port156during use. Referring toFIG. 8, rapid exchange segment154has a marker section174placed below side port156to again facilitate alignment of side port156. In alternative embodiments, a plurality of marker bands can be used and/or the rapid exchange segment can be formed from a radiopaque material.

An alternative embodiment of a rapid exchange segment for a deflection and support catheter is shown inFIG. 9. Rapid exchange segment180comprises a distal tubular element182, a connecting rod or wire184and proximal tubular element186, which connects to a rod or other elongated proximal element to extend out from the patient. Connecting rod184connects distal tubular element182with proximal tubular element186. During placement of the deflection and support catheter, distal tubular element182and proximal tubular element186ride over the medical device. The gap between the proximal tubular element186and distal tubular element182can function as the side port for deflection of the guidewire or other medical device. In alternative embodiments, a plurality of wires can connect distal tubular element182and proximal tubular element186with the gap between the tubular elements still functioning as a side port.

Referring toFIG. 10, deflection and support catheter190is shown clipped over guidewire or medical device192. In this embodiment, deflection and support catheter190comprises a rapid exchange segment194and proximal rod196. Rapid exchange segment194has a slit198extending along its length to facilitate clipping onto the guidewire192. Rapid exchange segment194further has a distal port200, a proximal port202and a side port204. Slit198extends form distal port200to proximal port202. Rapid exchange segment194has sufficient flexibility to open and close over guidewire192while having sufficient rigidity to remain over the guidewire as deflection catheter190is pushing into position. Slit198can be formed with overlapping sections, sections that meet, locking sections or other appropriate configurations that provide the functional features.

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 inFIGS. 11 and 12. Referring toFIG. 11, deflection and support catheter210comprises rapid exchange segment212and proximal rod214. Rapid exchange segment212has a distal segment216with a distal port218, proximal segment220with a proximal port222, and a curved segment224between distal segment212and proximal segment220. Side port226is located at the center of curved segment224where the curved segment in its natural shape is deflected furthest from the axis connecting distal port218with proximal port222. In this embodiment, rapid exchange segment212has a first radiopaque marker band228near distal port218and a second radiopaque marker band230near the distal edge of side port226. In some embodiments, the side port comprises a cut out of a portion of the tubular element in which the cut out has a length along the axis of the tubular element from about 1 to about 4 millimeters and a minimum circumference along the port of ⅓ of the average circumference around the tubular element away from the side port.

Referring toFIG. 12, deflection and support catheter240comprises rapid exchange segment242and proximal rod244. Rapid exchange segment242has a distal segment246with a distal port248, proximal segment250with a proximal port252, and a curved segment254. Side port256is located the outside proximal edge of curved segment254relative to the position of the curved segment in its natural shape that is deflected furthest from the axis connecting distal port248with proximal port252. In this embodiment, rapid exchange segment242has a first radiopaque marker band258near distal port248and a second radiopaque marker band260near the distal edge of side port256.

A two wire embodiment is depicted inFIG. 13. Referring toFIG. 13, deflection catheter270is interfaced with first guidewire272and second guidewire274. Guidewires272,274can be substituted for other appropriate elongated medical devices. Deflection and support catheter270comprises a proximal extension276and rapid exchange segment278. Rapid exchange segment278comprises a distal port280, a proximal port282and a side port284. In this embodiment, rapid exchange segment278has a curve, and side port284is located at the maximum deflection of the curve, although other placements of the side port can be used as desired. Generally, side port284is large enough for the passage of both guidewires272,274. First guidewire272and deflection and support catheter270can be advanced together over second guidewire274. Once side port284is in position, deflection and support catheter270can be held in place while first guidewire272is advanced out from side port284into a branch vessel. Then, second guidewire274and deflection catheter270can be removed from the patient with first guidewire272at its desired position.

A deflection and support catheter with a distal bent tip is shown inFIG. 14. Referring toFIG. 14, deflection and support catheter300has a proximal extension302, such as a proximal rod, and a rapid exchange segment304. Rapid exchange segment304has a proximal port306and a bent tip308with a distal port310. In some embodiments, bent tip308in its unstressed position can have an angle of at least about 35 degrees and in some embodiments at least about 45 degrees relative to the natural direction of the remaining portions of rapid exchange segment304. Referring toFIG. 15, guidewire316or other elongated medical device is extending through rapid exchange segment304and out from distal port310. A sufficient length of guidewire316extends from distal port310so that bent tip308flexes to a straighter configuration if any forces tend to hold guidewire316in a relatively straight position, such as would be the case in a blood vessel. Referring toFIG. 16, as guidewire316is moved in a proximal direction relative to deflection catheter300, bent tip308can resume its natural bent configuration with only guidewire tip318extending from distal port310. If distal port310is positioned at a branch vessel, guidewire tip318can be advanced into the branch vessel from distal port310.

Another embodiment of a deflection and support catheter is shown inFIGS. 17 and 18in which a side port is not used to deflect the medical device. Referring toFIG. 17, deflection and support catheter330comprises a proximal extension332and rapid exchange segment334having a distal port336and a proximal port338. As shown inFIGS. 17 and 18, rapid exchange segment334is straight and lacks a side port, although in alternative embodiments, the rapid exchange segment can have a side port that is not used and may be curved. Referring toFIG. 17, rapid exchange segment334is riding over medical device340, which can be a guide wire, microcatheter or other elongated medical device. For deployment, medical device340has a sharply bent tip portion342. As shown inFIG. 18, as deflection and support catheter330is advanced near the distal end of medical device340, rapid exchange segment334deflects bent tip portion342of medical device340to a less bent configuration that provides for placement into a branch vessel.

An embodiment of a support catheter is shown inFIG. 19A. Support catheter350comprises a proximal handle352, a connecting rod354and rapid exchange segment356with the connecting rod354connecting handle352with rapid exchange segment356. Handle352can be formed form any convenient to grip material that is suitable for sterile medical devices. Rapid exchange segment356comprises a tubular element358with a slit360and a gentle curved tip362. Two suitable, representative cross sections for tubular element358with slit360are shown inFIGS. 20A and 20B. As shown inFIG. 20A, two blunt edges meet at slit360. As shown inFIG. 20B, two lips370,372overlap at slit360. Also, the edges of the slit can interlock, such as with a keyed configuration, for example, as used with a locking plastic sandwich bag, or the like

Referring toFIG. 19B, rapid exchange segment374has a spiral shaped slit376that provides for easy mounting onto a medical device but increased resistance to accidental disengagement. The spiral shaped slit can be exaggerated further to form a cork screw rapid exchange segment, as shown inFIG. 19C. As shown inFIG. 19C, rapid exchange segment378has an exaggerated spiral slit380. Other configurations of the slit structure can be used to provide appropriate ability to expand slit360to place rapid exchange segment over a catheter or other elongated medical device while providing after placement over the medical device sufficient rigidity to advance rapid exchange segment356over the medical device without any significant chance of disengaging from the medical device inadvertently. Referring toFIG. 19D, support catheter382has a proximal push section382, a rapid exchange section384with a slit386and an overtube388. Overtube388can be slid off of rapid exchange section384for loading and slid over rapid exchange section384after loading to restrict disengagement. Friction holds overtube388in place after loading.

In one specific embodiment for use in coronary arteries, connecting rod354can have a length of roughly 95 centimeters, and rapid exchange segment356can 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 inFIGS. 21 and 22. As shown inFIG. 21, deflection and support catheter400has been deployed in a blood vessel402over a guidewire404or other catheter or elongated medical instrument and through a guide catheter406. Deflection and support catheter400has a side port408and a distal port410. As shown inFIG. 21, guidewire404is extending from distal port410, and side port408is positioned near the opening of branch vessel412.

Referring toFIG. 22, guidewire404is shown extending through side port408and into branch vessel412. Distal tip414of deflection and support catheter400extending distal from side port408helps to anchor the deflection and support catheter during the procedure. During the transition from the configuration shown inFIG. 21to the configuration shown inFIG. 22, guidewire404is pulled into distal tip414until the tip of guidewire404can exit side port408. Once guidewire404has exited side port408, the guidewire can be advanced into branch vessel412with support from deflection and support catheter400. Once the guidewire is within the branch vessel, the deflection and support catheter can be removed.

Referring toFIG. 23, a deflection and support catheter420is used to deploy a guide catheter422into renal artery424. Deflection and support catheter420is shown with a curved rapid exchange segment426, a proximal flexible rod428, a distal port430and a side port432. A shown inFIG. 23, the tip of guide catheter422is shown exiting side port432at the opening into renal artery424so that guide catheter422can be advanced into renal artery424with support form deflection catheter420.

Referring toFIG. 24, a deflection and support catheter440is used to deploy a guide catheter442into a coronary artery444from aorta446. Deflection and support catheter440is shown with a curved rapid exchange segment448, a proximal flexible rod450, a distal port452, a proximal port454and a side port456. A shown inFIG. 24, the tip of guide catheter442is shown exiting side port456at the opening into coronary artery444so that guide catheter442can be advanced into coronary artery444with support form deflection/support catheter440.

The use of a support catheter generally with an elongated medical device460is depicted inFIGS. 25 and 26. The elongated medical device460includes a treatment catheter470carrying a treatment structure480. Referring toFIG. 25, a distal portion of elongated medical device460(e.g., a portion of the treatment catheter470) extends out from guide catheter472into vessel474on guidewire476. Guidewire476extends past lesion478, but it is difficult to advance the treatment structure480on treatment catheter470to lesion478due to the extent of blockage from lesion478and the bending of vessel474. Referring toFIG. 26, support catheter486has a proximal segment488and a rapid exchange segment including a tubular element490and a slit492such that the tubular element490can be clipped onto a proximal portion of treatment catheter470. Tubular element490is advanced through a Tuohy-Borst valve or the like, through the guide catheter to extend from guide catheter472into vessel474. In some embodiments, tubular element490can be extended up to 10 to 12 centimeters into the vessel, such as a coronary artery, graft or the like. With additional support from support catheter486, treatment structure480can be advanced to lesion478where a balloon angioplasty, stent deployment and/or other treatment can be performed. Once the lesion is crossed, support catheter486can be removed. Suitable angioplasty balloons are described further, for example in U.S. Pat. No. 6,132,824 to Hamlin, entitled “Multilayer Catheter Balloon,” incorporated herein by reference. Stent delivery is described further, for example, in U.S. Pat. No. 6,610,069 to Euteneuer et al., entitled “Catheter Support For Stent Delivery,” incorporated herein by reference. Various stents and angioplasty balloons are commercially available.

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.