A deflectable catheter assembly and methods of use are herein disclosed. The catheter assembly, in one embodiment, is deflectable and includes a first catheter, a second catheter, and a third catheter. The second catheter fits coaxially within the first catheter. In some embodiments, the first and/or second catheter can be constituently different from proximal end to distal end. At least one of the first catheter and the second catheter include a deflectable portion to allow deflection of that catheter from a first position to a second position. The third catheter has a sheath and a medical instrument positioned within the sheath. The third catheter fits coaxially within the second catheter.

FIELD OF INVENTION

BACKGROUND

Systems currently exist that supply therapeutic substances through a medical instrument to regions of a patient's body. Such regions may include a diseased blood vessel, body cavity or organ. In the case of a diseased blood vessel, for example, the therapeutic agent may be used to treat an arterial lesion and/or to promote an angiogenic response.

Medical instruments such as needles and ablation electrodes attached to the distal end of a catheter assembly are used to treat regions within the patient's body. For example, in applying or delivering a therapeutic substance that promotes angiogenesis, a catheter with a needle disposed therein may be guided through the body to the left ventricle of the heart where the needle delivers a therapeutic agent to the left ventricle wall. U.S. Pat. No. 6,120,520, for example, describes a catheter which may be guided through blood vessels in the body to the left ventricle in order to deliver a bioagent into the ventricle's wall. U.S. Pat. Nos. 6,251,104 and 6,102,926 also describe catheters which may be used to guide a treatment device (e.g. a tissue ablation device) through the body and into the left ventricle for treatment of the myocardium.

These types of catheter systems eliminate the need for prior intra-operative procedures, such as a procedure in which the chest cavity is opened to penetrate the heart wall. Intra-operative procedures can subject a patient to prolonged recovery periods and can often lead to further complications. However, there are many difficulties associated with guiding a catheter through the body and introducing the catheter into a particular body cavity or vessel wall. One such difficulty is the maneuverability of the catheter for advancing it through the body while maintaining sufficient strength and rigidity. Often catheters are not shaped adequately for maneuvering through particular portions of the body or to fit a particular body cavity. In addition, catheters are often insufficiently flexible to be maneuvered properly within the particular body cavity.

Another difficulty is maneuvering a medical instrument attached to the catheter to a particular target area in the body cavity. For example, difficulties may arise in positioning the medical instrument within the left ventricular cavity after the distal end of the catheter has extended into the ventricular cavity. The catheter may have sufficient rigidity and strength to be inserted into the body cavity. However, a problem can occur when the catheter is not sufficiently flexible to position the medical instrument to a target site within the body cavity.

SUMMARY OF INVENTION

Embodiments of a catheter assembly and methods of use are disclosed herein. In some embodiments, the catheter assembly includes a first catheter, a second catheter, and a third catheter. The second catheter can fit coaxially within the first catheter. In some embodiments, the first and/or second catheter can be constituently different from proximal end to distal end. At least one of the first catheter and the second catheter can include a deflectable portion to allow deflection of the catheter from a first position to a second position, and the other of the first catheter and second catheter includes a portion which is preshaped (e.g. an angled portion formed by two segments of the angled portion). The third catheter can have a sheath and a medical instrument positioned within the sheath. The third catheter can fit coaxially within the second catheter.

DETAILED DESCRIPTION

FIG. 1illustrates a plan view of one embodiment of a catheter assembly disposed within a left ventricle of the heart. Catheter assembly100is shown to be extending from the aortic valve into the left ventricle of the heart. Catheter assembly100includes a first catheter110, a second catheter140, and a third catheter180. Second catheter140can fit coaxially within first catheter110. Third catheter180can fit coaxially within second catheter140. Each catheter is free to move longitudinally and radially relative to the other catheters. In one embodiment, first catheter110may be an outer guide. In one embodiment, third catheter180may be a needle catheter which has a lumen therethrough that may accommodate a needle. In another embodiment, third catheter180may be adapted to deliver other devices to a treatment site, such as an ablation device.

In some embodiments, catheter assembly100may be used for local delivery of bioagents such as, but not limited to, cells used for cell therapy, one or more growth factors used for angiogenesis or arteriogenesis, or vectors containing genes for gene therapy, to the left ventricle. In one embodiment, catheter assembly100may be used in delivering cells to treat heart failure or to treat one or more portions of the heart which are ischemic. Catheter assembly100uses coaxially telescoping catheters110,140, and180, at least one or more being deflectable, to position a medical instrument at different target sites within a body organ such as the left ventricle. Catheter assembly100can be flexible enough to bend according to the contours of the body organ. Catheter assembly100is flexible in that catheter assembly100may achieve a set angle according to the medical procedure required. Catheter assembly100will not only allow some flexibility in angle changes, but can move in a three coordinate system allowing an operator greater control over its movement.

In one embodiment, one catheter in catheter assembly100includes a deflectable portion. The deflectable portion allows catheter assembly100the flexibility to bend according to the contours in a particular body organ. In one embodiment, the flexible portion is a part of first catheter110. In an alternative embodiment, the flexible portion is a part of second catheter140. In other alternative embodiments, both first catheter110and second catheter140may include deflectable portions.

Also, in certain embodiments, one of first catheter110and second catheter140includes a shaped portion which is a portion having a fixed, predetermined initial shape from which deflections may occur. For example, second catheter140shown inFIG. 1includes, at its distal portion, a fixed, predetermined initial shape in which a first and second distal portion of second catheter140form an initial angle which determines this initial shape. This initial angle may be between about 75 degrees to about 150 degrees. In the example shown inFIG. 1, the distal portion of second catheter140has two portions which form a pre-shaped angle of about 90 degrees. The deflectable portion of first catheter110, in combination with the preshaped portion of second catheter140, allow for the distal tip of third catheter180to be selectively and controllably placed at a multitude of positions. It will be appreciated that the deflectable portion may alternatively be on the second catheter and the preshaped portion may be on the first catheter.

FIG. 2aillustrates a side view of one embodiment of first catheter110ofFIG. 1. First catheter110acts as a guiding catheter. First catheter110provides support and orientation direction to the other catheters140and180. In one embodiment, first catheter110provides support and orientation to the other catheters140and180across the aortic valve.

As shown inFIG. 2a, first catheter110includes a shaft with a proximal end122and a distal end124. In one embodiment where first catheter110includes a deflectable portion, the shaft is made up of a stiff portion114and a deflectable portion116as shown inFIG. 2a. The difference in stiffness may be achieved by having a wire braid reinforcement along the stiff portion and no wire braid reinforcement along the deflectable portion; other ways to achieve this difference include using different materials in the two portions. The difference in stiffness may range from about 72 D durometer to about 40 D durometer. The distal end portion of the first catheter which is not reinforced (and hence more flexible) may range from about 40 mm to about 120 mm in length. Location115shows, in one exemplary embodiment, the transition area between stiffer portion114and deflectable portion116; as noted herein, this transition may be achieved by having a reinforcement layer or material in one portion and not having this layer or material in the other portion. It will be appreciated that both stiffer portion114and deflectable portion116are normally flexible enough to allow both portions to pass through a patient's vasculature (e.g. from an entry point into the femoral artery to a destination within the left ventricle or within a coronary artery). In an alternative embodiment where first catheter110does not include a deflectable portion, the shaft may be made up entirely of stiff portion114which resists deflection.

In one embodiment, first catheter110may also include a soft distal tip118at distal end124of the shaft. Soft distal tip118can be a soft polymer ring that is mounted at distal end124of first catheter110to reduce trauma incurred as catheter assembly100moves through the body.

In one alternative embodiment, first catheter110may be made to have different preshapes. The pre-shapes allow first catheter110to enter into specific body cavities and rest in preset positions. For example, once it is delivered into the ventricle, first catheter110with a certain preshape rests in the ventricle with preferential positioning. The pre-shape typically includes at least one preset angle between portions of the first catheter; in the example ofFIG. 1, the two portions define an obtuse angle.

In one embodiment, the outer diameter of first catheter110is approximately 8 French or less. This is the case if second catheter140, not first catheter110, includes the deflectable portion. If the deflectable portion is on first catheter110, then the outer diameter of the second catheter140is 6 French. In one embodiment, if the deflectable portion is on second catheter140, then the outer diameter of the second catheter140can be 7 French.

FIG. 2aalso illustrates a pull wire112. Pull wire112may be located inside a lumen (e.g. lumen211shown inFIG. 2b) of tubing that runs along first catheter110. Pull wire112is attached to an anchor band A1near the soft distal tip118. When pull wire112is pulled, deflectable portion116bends as shown by arrow117. In one embodiment, the tubing that houses pull wire112may be made out of poly[trans-1,2-di(2-furyl)ethylene] (PDFE). In an alternative embodiment the tubing that houses pull wire112may be made out of any other flexible polymer. In another alternative embodiment, the tubing that houses the pull wire112may be made out of a stacked coil. The wire used for the stacked coil can be any metallic material such as stainless steel, Nitinol, etc. The stacked coil helps to resist compression of the catheter shaft when the pull wire is in tension.

FIG. 2billustrates a cross-section of stiff portion114(taken at location115b) of first catheter110shown inFIG. 2a. As shown inFIG. 2b, the stiff portion114of first catheter110includes a liner212, a braided reinforcement214, and a jacket216. Jacket216includes a lumen211, formed in jacket216, and pull wire112passes through lumen211as shown inFIGS. 2band2c. In one embodiment, to build stiff portion114of shaft, a mandrel is inserted inside of liner212for support. Liner212may be made of PTFE (polytetrafluoroethylene) to produce a lubricious inner lumen surface. Interior lumen210of liner212is designed to hold the second catheter which coaxially fits within this lumen of liner212. The outer surface of the PTFE liner is chemically etched to promote adhesion with other materials. Next, a reinforcement material214is fabricated onto the outside layer of liner212. In one embodiment, reinforcement material214may be braided. Reinforcement material214may be one layer or multiple layers. Next, tubing for pull wire212is placed on reinforcement material214. Next, a jacket216is attached to the outside of reinforcement material214. Shrink tubing (not shown) is wrapped around the outside of the jacket216and heated. The shrink tubing will shrink down and cause the other materials to be pushed inward in a fusing process. Accordingly, jacket216will melt, penetrating the braid214, if the reinforcement material214is a braided structure, and attach to reinforcement material214and the liner212.

FIG. 2cillustrates a cross-section of flexible portion116(taken at location115c) of first catheter110shown inFIG. 2a. Flexible portion116is similar to stiff portion114but does not include reinforcement material214ofFIG. 2b. Instead, flexible portion116includes jacket216wrapped around liner212with lumen210. Pull wire112within lumen211remains in jacket216. The outer diameter of the cross-section of the portion116may be less than the outer diameter of the cross-section shown inFIG. 2b. The absence of the reinforcement material at the distal portion of the first catheter allows this distal portion to be more flexible than a proximal portion of the first catheter. When pull wire112is pulled, the distal portion deflects while the stiffer proximal portion does not deflect.

In one embodiment, flexible portion116may include a second type of reinforcement material layer (not shown) between liner212and jacket216. The second type of reinforcement material would be substantially less stiff than reinforcement material214of stiff portion114. This second type of reinforcement material may be a metallic multi-ring structure to help maintain the lumen's opening (e.g. lumen210) when this portion of the catheter is deflected. It is noted thatFIGS. 2band2cdo not show the second and third catheters within the lumen210.

In the process of making first catheter110, the mandrel which is inserted into lumen210may be made of wire. In an alternative embodiment, the mandrel may be a glass filled polymer. In another alternative embodiment, the mandrel may be made of other materials, such as polymeric materials, such as a mandrel made of PTFE (polytetrafluoroethylene) that can withstand heat (e.g. such that the material does not melt) when heat is applied to the shaft during the fusing process.

In one embodiment, reinforcement material214may be made with stainless steel. In an alternative embodiment, reinforcement material214may be made with nickel titanium wires. In another alternative embodiment, reinforcement material214may be made with nylon wires. In other embodiments (not shown), the reinforcement material may be braided. In other embodiments (not shown), the reinforcement material may be a stacked coil or a metallic multi-ring structure.

In one embodiment, the tubing that houses pull wire112may be positioned within liner212. In an alternative embodiment, the tubing may be placed between reinforcement material214and outer jacket216. In that case, a first layer of reinforcement material214may be underneath the tubing with pull wire112, and a second layer of reinforcement material may be on top of the tubing with pull wire112. In another embodiment, multiple pull wires, in corresponding lumens in the jacket216, may be used to control deflection of the first catheter.

FIG. 3aillustrates a diagram of one embodiment of second catheter140ofFIG. 1. As discussed above, second catheter140may include a flexible portion in one embodiment. In an alternative embodiment, second catheter140may not include a flexible portion. In the embodiment shown inFIG. 3a, second catheter140includes a shaft152having a proximal end154and a distal end156. Shaft152includes a stiff portion146and a portion148which may be a flexible portion or it may have a predetermined initial shape. If portion148has a predetermined initial shape, it may also be deflectable from this initial shape. The shaft construction of second catheter140is similar to the first catheter110but may be made of material with relatively softer durometer ranging approximately from 70 D durometer to 30 D durometer. In one embodiment, shaft152also includes a soft distal tip150(which is formed from a very low durometer material).

In one embodiment, second catheter140may include a flush port144and a self-seal valve142. Self-seal valve142ensures that fluid does not flow between second catheter140and third catheter180. Flush port144allows flushing of fluid at any time. In an alternative embodiment, first catheter110may also include a self-seal valve and a flush port. Flush port144may also be used to inject contrast media into the body organ to allow visualization of the body cavity.

In one embodiment, the distal end156of second catheter140has a predetermined initial shape. This predetermined initial shape is typically an angle formed between two portions of this distal end. Distal end156of second catheter140may be designed to provide support to third catheter180through this predetermined shape. The shape will allow second catheter140to direct third catheter180to a target (e.g. seeFIG. 1). In one embodiment, an angular range for shaped distal end156of second catheter140is approximately in the range of between 0 degrees to 150 degrees. In the case ofFIG. 3a, two exemplary angles of 90 degrees and 150 degrees are shown.

In one embodiment, where portion148is deflectable, second catheter140is approximately a maximum of 10 centimeters in length longer than the first catheter110. On second catheter140, the deflectable portion is no more than approximately 8 centimeters. Third catheter180extends less than 8 centimeters from the end of the distal end of second catheter140. In one embodiment, the third catheter extends 1 or 2 centimeters. The length of third catheter180is dependent on the width and length of the heart. It will be appreciated that different sizes may be used, and these different sizes would normally be determined by the size of the organ which is intended to receive the catheter.

FIG. 3billustrates a cross-section of stiff portion146of second catheter140ofFIG. 3ataken at B-B ofFIG. 3a. Similar toFIG. 2b, stiff portion146includes a liner312. Liner312has a hollow core which is lumen310which is designed to coaxially receive the third catheter which is rotatably and slidably moveable within lumen310. A reinforcement material314is fabricated onto liner312. A jacket316circumferentially surrounds reinforcement material314. In one embodiment, shrink tubing (not shown) is placed around jacket316. Heat is applied, and the shrink tubing shrinks to cause reinforcement material314(e.g. wire braid) to become attached to liner312. Jacket316also then becomes attached to reinforcement material314. If the reinforcement material is a braided structure, material of jacket316may penetrate through reinforcement material314and become attached to liner312.

FIG. 3cillustrates a cross-section of portion148of second catheter140ofFIG. 3ataken at C-C atFIG. 3a. The cross-section is similar to the cross-section ofFIG. 3bexcept that the portion148may not include a reinforcement material314. Instead, the portion148includes a liner312and a jacket316circumferentially surrounding the liner312. In alternative embodiments, a second type of reinforcement material (not shown) may be etched or placed between liner312and jacket316for portion148. This second type of material may be a metallic multi-ring structure to help maintain the lumen dimension (e.g. the opening of the lumen) when this portion148of second catheter140is deflected (if it is deflectable).

FIG. 4aillustrates a side view of a portion of an embodiment of third catheter180inFIG. 1. Third catheter180guides a medical instrument, such as a needle, to a target area. In one embodiment, third catheter180may be a needle catheter as shown inFIG. 4a. Third catheter180includes a needle sheath186housing a needle182. Needle is182moveable longitudinally through sheath186, and the lumen of the needle extends from a proximal end of needle to the needle tip184. Needle sheath186has a proximal end196and a distal end198. A needle tip184of the needle182is extendable from distal end198of needle sheath186(as shown inFIG. 4a). While needle182is shown as a straight needle with a sharp tip, other types of needles, such as helical (e.g. corkscrew-like) needles may also be used in certain embodiments.

In one embodiment, the outer diameter of needle sheath186is between 40 to 60 thousandths of an inch. In one embodiment needle182is a 25 to 27-gauge needle. This may be the case if the outer diameter of first catheter110is approximately 8 French. The outer diameter may change if the diameter of first catheter110increases.

In one embodiment, third catheter180may include one or more stabilizers. As seen inFIG. 4a, the stabilizer in one embodiment is a balloon188. Balloon188is located near distal end198of needle sheath186. Balloon188, in this case a tire tube shaped balloon, allows third catheter180to approach the target with needle182perpendicular to the target. That is, the tire tube shaped balloon will tend to prevent a needle injection at an angle other than approximately 90 degrees into the target tissue. In addition, balloon188allows for a larger surface area of control so needle tip184or needle182does not wobble. For example, as third catheter180approaches a wall of the left ventricle, balloon188is positioned against the wall of the left ventricle. Needle182then extends from sheath186and penetrates in some embodiments, the left ventricle wall. Balloon188thereby allows for a larger surface area of control against the left ventricle wall to stabilize the needle182and hold needle182perpendicular to left ventricle wall as it penetrates through the surface of the wall.FIG. 4fshows a front perspective view of the needle and balloon ofFIG. 4a.FIG. 4gshows a front perspective view of another embodiment of the third catheter in which a set of balloons188A, B and C (e.g. three balloons, each coupled to one of the lumens) acts as a stabilizer which is coupled near a distal end of third catheter180.

FIG. 4billustrates a cross-section (taken at point186B) of third catheter180ofFIG. 4a. In one embodiment, and as shown inFIG. 4b, three balloon lumens194are placed between needle182and the outer layer of sheath186. Each balloon, such as balloon188(e.g., seeFIG. 4g), may use a separate balloon lumen194. In one embodiment, one balloon lumen194may used with one balloon stabilizer. In alternative embodiments, additional balloon lumens194may be used for only one balloon stabilizer or for more than one balloon stabilizer. InFIG. 4b, the three balloon lumens194are positioned relative to sheath186at various points to provide additional strength to the structure of third catheter180. This additional strength allows for additional stabilization and prevents buckling of third catheter180. In one particular embodiment, shown inFIG. 4b, three balloon lumens194are coupled to a single tire tube shaped balloon188(not shown) which is attached to the distal end of third catheter180as shown inFIG. 4a. These three balloon lumens194, when inflated, tend to give additional strength to the third catheter. These three balloon lumens194are arranged substantially equidistant in relative to the outer circumference of sheath186in order to provide a substantially equal distribution of support to the third catheter; in particular, they are separated by about 120 degrees. These lumens194are created by tubular liners405which are embedded, in one embodiment, into sheath186. Another tubular liner401forms lumen403which slidably receives needle182. Lumen403extends from the distal end of third catheter180to the proximal end of third catheter180. Lumens194extend from proximal end196to distal end198. At or near distal end198, lumens194can be in fluid communication with balloon(s)188. At or near proximal end196, lumens194can be in fluid communication with a source for an inflation fluid which is used to inflate balloon(s)188. Lumen407is an optional lumen for use with a pull wire (not shown) which may be used to deflect third catheter180in certain embodiments.

FIG. 4dillustrates a cross-section of an alternative embodiment of third catheter180ofFIG. 4a. In one embodiment, third catheter180is made of a liner185which surrounds a lumen185A, a jacket187and peripheral lumens195. In one embodiment, liner185is made of a lubricious polymer such as PTFE or HDPE (High Density Polyethylene). Liner185may also be structured similar to the first and second catheters in that it has a lubricious sub-liner, reinforced on the outside by a braid or coil structure, and surrounded by a jacket material that all are fabricated using the heat process described for the first and second catheters. The jacket material may be polyimide such that it is coated on, instead of heat fused on, liner185. This kind of structure gives the stiffness needed for small third catheter180. Peripheral lumens195may be constructed in several ways. In one way, it may be constructed by bonding polyimide tubes in between liner185and jacket187. This offers additional rigidity to third catheter180. It may also be formed by placing processing mandrels in between jacket187and liner185during the heat fuse process. The mandrels are removed after the process and lumens195are formed. Lumen185A is a channel through which a medical instrument, such as needle182, slidably extends.

In certain embodiments, the shape of the balloon188may vary. It should be noted that the balloon188should collapse back, when not inflated, to the original shaft size of third catheter180. Therefore, balloon188is generally made of elastomer materials.

FIG. 4cillustrates a cross-section of an alternative embodiment of a needle182with a needle stop190. Needle sheath186is shown extending from second catheter140. Needle sheath186houses needle182. InFIG. 4c, needle182includes one or more needle stops190. Needle stops190allow needle182to extend from the distal end of needle sheath186and penetrate tissue to a predetermined depth. Needle182extends from needle sheath186and begins penetrating body tissue. As needle182is extended, needle stops190also contacts the tissue preventing needle182from extending further into the tissue. Accordingly, needle182is automatically stopped from extending further into body tissue when needle stop190contacts the body tissue. Needle stops190may be placed a predetermined distance from the tip of needle182so that needle182only penetrates the tissue a predetermined amount. Needle stop190effectively removes control of the penetration depth of the needle from the operator and therefore reduces operator error.

In one embodiment of the arrangement shown inFIG. 4c, needle stop190may be a ring around needle182. The ring may be glued onto needle182. In an alternative embodiment, the ring may be a melted polymer around needle182. In another alternative embodiment, the ring may be encased in platinum or gold for purposes of visibility. It should be noted that needle stop190could be soldered onto needle182as well. In one embodiment, needle stop190may be made of nickel titanium, which has to be glued rather than soldered to needle182.

FIG. 4eillustrates a cross-section of an alternative embodiment of a needle stop arrangement which includes a needle stop192attached to the distal end of needle182. In this embodiment, a ring191is assembled on the inner surface of needle sheath186. Ring191is fixedly attached to this inner surface and has an opening which allows the distal end of the needle to pass beyond the ring and beyond the end of sheath186. The stop192on the needle will not pass through the opening in ring191. When the needle182is extended forward to penetrate the tissue to a pre-determined distance, needle stop192on the needle engages the ring191on needle sheath186, and causes the needle to stop extending, thereby limiting the penetration of the needle. Stop192and ring191function to limit the penetration of the needle (thereby preventing the needle from making a puncture completely through the wall of the left ventricle, for example) and to also set a predetermined penetration depth (based on the placement of stop192on the needle relative to the needle's length beyond the stop192and the position of ring191in the sheath).

In those embodiments which use at least one needle, the needle may be a hollow tube with a beveled distal tip and a proximal hub attachment with an injection port. The needle may be made of a metallic material such as stainless steel, nickel titanium, platinum, etc. The needle will typically have enough flexibility to be pushed through a patient's vasculature and still not buckle when the distal tip is pushed into penetration with the patient's tissue (e.g. into the myocardium within the left ventricle).

In one embodiment, third catheter180includes a proximal hub with an injection port. The injection port is connected to the needle lumen to allow fluid communication from the injection port to the needle lumen, thereby allowing the introduction of a bioagent from the injection port and into the needle lumen and then into the tissue penetrated by the distal tip of the needle. The proximal hub with the injection port may include a luer lock. In another embodiment third catheter180may also include a self-seal valve and a flush port. The medical instrument, such as the needle, runs inside of the self-seal valve.

FIG. 5illustrates a cross-section of a heart with the aorta and ventricle open partially to demonstrate the use of catheter assembly100. Catheter assembly100accesses the ventricle through the aorta. A guide wire (not shown) and an introducer sheath (not shown) are first introduced into the femoral artery from the groin area (not shown); other entry sites may alternatively be used. The guide wire is then tracked through the aorta across the aorta valve. Then, first catheter110is inserted through the introducer sheath and is tracked over the guide wire into the left ventricle. The distal end of first catheter110is deflected so that the first catheter's distal tip is pointed in a direction approximately parallel to the wall of the target injection site. The guide wire is then removed from the vessel.

Second catheter140and third catheter180are introduced into the inside of first catheter110and into the left ventricle. Once first catheter110enters the left ventricle from the aortic valve, first catheter110may be deflected to position second and third catheters140and180towards the target wall. The deflection may be achieved by pulling wire112in lumen211in the case of the first catheter110shown inFIG. 2a. Second catheter140is extended to bring third catheter180close to the wall. Extension and rotation of the second catheter140positions a medical instrument such as a needle along the length and radial wall of the left ventricle. In one embodiment, one or more electrodes may be positioned in one or more of the catheters to sense wall contact or to sense electrophysiological activity of the heart's wall or to sense oxygen levels or other parameters in the myocardium.

With support from second catheter140, third catheter180extends out a small distance to reach the wall. The needle then extends out a fixed length to puncture into the myocardium to deliver a bioagent. In one embodiment, a medical instrument such as a laser compatible optical fiber may be used in place of the needle. In alternative embodiments other medical instruments, such as laser ablater or RF ablater or a sensor (such as a sensor to detect eletrophysiological activity or oxygen content in the myocardium) may be used with catheter assembly100in place of the needle. In other embodiments, the third catheter includes a needle and another medical instrument such as an electrophysiological sensor or an oxygen sensor. In yet other embodiments, the third catheter includes a medical instrument and a transducer coil or other transducer which is used to determine the position of the catheter by, for example, measuring the magnetic field received by a transducer coil which is positioned near the distal end of the third catheter.

In one embodiment, catheter assembly100may be delivered into the left ventricle without use of a guide wire. In this case, first catheter110is first introduced into the aorta through the introducer sheath (not shown). Right before crossing the aortic valve, the distal end of first catheter110is pulled to curl back to form a tight loop. Then first catheter110is advanced through the aortic valve. The looped distal end prevents injury of the aortic valve due to the movement of first catheter110.

In one embodiment, catheter assembly100may be made to be magnetic resonance imaging (MRI) compatible. To do so, the material selection for all components have to be such that it does not cause artifacts in a MR imaging procedure. To achieve this, the materials should be made with non-magnetizable materials. The braid wire can be either NiTi or Nylon instead of stainless steel. The needle can be NiTi or polymer such as reinforced Polyimide or PEEK. The reinforcement material for the needle can be NiTi or Nylon, instead of stainless steel. The basic design for catheter assembly100can remain the same. There may be adjustment of material stiffness needed to achieve the same overall properties of the catheter assembly. This may be done by replacing polymeric material with higher durometer grades to increase the stiffness sacrificed by, for example, replacing the stainless steel with the elastic NiTi in the braid.

FIG. 6illustrates an alternative embodiment of a second catheter640. Second catheter640includes a shaft620having a proximal end622and a distal end624. Shaft620includes a stiff portion646and a flexible portion648. In one embodiment, second catheter640also includes a soft distal tip650. The soft distal tip650may be similar to the one shown inFIG. 2a. InFIG. 6, second catheter640is also shown to have radiopaque markers652. The radio opaque markers652may be spaced evenly at a distance ranged approximately between 5 millimeters to about 1 centimeter apart. However, in alternative embodiments, radiopaque markers652may be spaced unevenly and at different distances. In addition, in another alternative embodiment, radiopaque markers652may be fabricated on the entire second catheter640. This marker system is used as a ruler. Often the therapy has to be delivered to multiple locations. Opaque markers652act as a ruler to help keep track of delivery locations by displaying the extension distance of second catheter640relative to the first catheter. In one embodiment, similar to what is shown inFIG. 2a, the second catheter640ofFIG. 6includes a flush port644and a self-seal valve642.

FIG. 7illustrates an alternative embodiment of a first catheter710with a control handle for deflection of first catheter710. The control handle comprises a control knob120and a handle body910. A pull wire or tendon wire (not shown) is attached to an inner component that is moveable by a control knob120shown on the outside of first catheter710. In one embodiment, by pulling control knob120towards a proximal end716, first catheter710is under tension and is therefore deflected at a distal end718. To straighten out first catheter710, control knob120is pushed forward. A similar control handle may be used on the second catheter if it is desired to make the second catheter deflectable. In another embodiment, proximal end716is internally attached to control knob120. The tendon wire is internally attached to body910of the control handle. By pulling body910of the control handle away form control knob120towards a proximal end716, first catheter710is under tension and is therefore deflected at a distal end718. To straighten out first catheter710, control knob120is pulled near handle body910.

FIG. 8aillustrates a side view cross-section of a catheter assembly according to embodiments of the present invention. Catheter800includes proximal section802and distal section804. Catheter800can be an assembly of tubular structures housed within each other and generally forming a tube-like construction overall. In some embodiments, both proximal section802and distal section804of catheter800include at least three tubular structures interdisposed within each other. The lumen of proximal section802is in fluid communication with the lumen of distal section804; however, the materials used to construct proximal end802and distal end804may differ in certain material characteristics. In some embodiments, the materials may be the same.

In one embodiment, catheter800can include inner shaft806which can extend the length of proximal section802and distal section804. Inner shaft806can be made of a polymer with lubricious luminal surface characteristics which can allow for ease of movement for a therapeutic tool. Inner shaft806can have a durometer of between 45 D and 72 D. In some embodiments, inner shaft806can be made of a low friction material such as HDPE or ePTFE.

Examples of therapeutic tools that can be used in conjunction with inner shaft806include, but are not limited to, a needle, a biopsy clamp and a catheter with ultrasonic transducers. Alternative embodiments include a laser compatible optical fiber, a laser ablater or RF ablater or a sensor (such as a sensor to detect eletrophysiological activity or oxygen content in the myocardium). In other embodiments, a combination of a needle and another medical instrument such as an electrophysiological sensor or an oxygen sensor can be used in conjunction with inner shaft806. In yet other embodiments, a medical instrument and a transducer coil or other transducer which is used to determine the position of the catheter by, for example, measuring the magnetic field received by a transducer coil which is positioned near the distal end of catheter800can be used in conjunction with inner shaft806.

In embodiments in which a needle is the therapeutic tool, bioagents such as stem cells, growth factors, gene, and vectors can be locally delivered to the treatment site. In addition, proteins, peptides and synthetic pharmaceuticals, such as an anti-inflammatory or immune modulating, anti-migratory, anti-thrombotic or other pro-healing agents or a combination thereof. The type of treatment agent delivered to the treatment site is virtually unlimited.

Referring to proximal section802inFIG. 8a, catheter800can include middle shaft808ahousing inner shaft806. That is, the luminal surface of middle shaft808acan be completely or substantially in contact with the abluminal surface of inner shaft806in proximal section802. In one embodiment, middle shaft808ais a coiled shaft and inner shaft806is fitted tightly therein. In one embodiment, middle shaft808acan be made of multiple layers of stacked coiled tubular structures with each coiled tubular structure winding towards the opposite direction from the coiled tubular structure under or above, respectively. In one embodiment, middle shaft808aincludes three stacked coil tubular structures. To form a coiled tubular structure, in some embodiments, a wire can be wound on a mandrel such that there are no gaps in between adjacent coils forming a coiled tubular structure. The wire may be, for example, stainless steel, NiTi or nylon. The multiple layers of middle shaft808acan form an inter-locking shaft structure that transmits torque efficiently in either rotational directions of catheter800when deployed during a medical procedure.

Outer shaft810, which includes outer shaft sections810aand810b, can serve as the outer housing for catheter800. Outer shaft810can encompass middle shaft808, i.e., both sections810aand810b. Relative to outer section810b, outer section810acan be stiffer. Outer shaft section810a, which is located within proximal section802, can be made of a material such as Pebax® or Nylon. Outer shaft section810b, which is located within distal section804, can be made of a material which is more flexible than the materials of outer section810a. For example, materials of outer shaft810bcan include, but is not limited to, Pebax®, polyurethane, and polyethylene. In one embodiment, one or more electrodes may be positioned on the circumference of outer shaft810to sense wall contact or to sense electrophysiological activity of the heart's wall or to sense oxygen levels or other parameters in the myocardium.

In some embodiments, tendon sheath814housing tendon wire816can reside between the abluminal surface of middle shaft808aand the luminal surface of outer shaft810a. In one embodiment, a gap812remains in a portion of proximal section802between the abluminal surface of middle shaft808aand the luminal surface of outer shaft810a. In other words, gap812does not reside the length of proximal section802, but instead only an intermediate portion thereof. In one embodiment, tendon sheath814wraps around middle shaft808aand is “free-floating” within gap812. That is, tendon sheath814should preferably wrap around middle shaft808aloosely rather than tautly in gap812. For applications in which catheter800is utilized in curved anatomical lumens, the wrapping of tendon sheath814may ensure balancing of the materials over a cross-section of proximal section802over a shaft section lying within a curved anatomical location such as the aortic arch. The aortic arch is a curved segment of the aorta that the catheter, if used to target a therapy in the left ventricle accessing the body from the femoral artery, must pass by. Other curved anatomical locations can be the turn from superior vena cava into the right atrium and the turn from right atrium into the coronary sinus, for example. The pitch of the wrap is dictated by the estimated length of a curved anatomical path. “Pitch” refers to the number of wraps with a given length of the catheter shaft. The pitch increases if the number of wraps decreases within the given length of the catheter shaft. In some embodiments, tendon sheath814is wrapped around middle shaft808afor at least one pitch within gap812. The “free-floating and wrapping” characteristic of a portion of tendon sheath814may reduce stored torque and/or eliminate preferred orientation of proximal section802when deployed during a medical procedure.

At both a proximal end and a distal end of proximal section802, outer sheath810amay be heat-fused or adhesive-bound to middle shaft808a. Thus, tendon sheath814is immobilized within the proximal end and the distal end of section802, while simultaneously free-floating within gap812. Examples of adhesive material which may be used include, but are not limited to, ultraviolet-cured adhesive, instant-cured cyanoacrylate, and heat-cured adhesive.

FIG. 8brepresents a front cross-section view of catheter800taken at lines B-B ofFIG. 8a. This cross-section is within the intermediate portion of proximal section802wherein gap812resides. In this view, catheter800includes inner shaft806which is surrounded by middle shaft808awhich in turn is surrounded by outer shaft810a. In one embodiment, middle shaft808acan include three coiled shafts (as described above) stacked closely together. Between middle shaft808aand outer shaft810aresides gap812. As shown, tendon sheath814housing tendon816resides in gap812. Tendon816can be used to control the movement of distal section804when catheter800is deployed within, for example, a curved anatomical path. The stacked coil configuration of middle shaft808ashould not allow longitudinal length changes in proximal section802even when a compression force is applied due to pulling of tendon816when deployed during a medical procedure.

Similarly,FIG. 8crepresents a front cross-section view of catheter800taken at lines C-C ofFIG. 8a. As withFIG. 8b, this cross-section is also within the intermediate portion of proximal section802wherein gap812resides. InFIG. 8c, tendon sheath816is shown positioned at approximately 180° relative to tendon sheath816shown inFIG. 8b. Together,FIGS. 8band8cillustrate an embodiment of tendon sheath816half wrapped half way around middle shaft808awithin gap812of an intermediate portion of proximal section802, e.g.,FIGS. 8band8cshow catheter800at two points between which tendon sheath816wraps one-half of a revolution around middle shaft808a.

Referring to distal section804inFIG. 8a, catheter800can include middle shaft808bhousing inner shaft806. That is, the luminal surface of middle shaft808acan be completely or substantially in contact with the abluminal surface of inner shaft806. In some embodiments, middle shaft808bof distal section804should be more flexible relative to middle shaft808aof proximal section802. In some embodiments, middle shaft808bis a coiled shaft and inner shaft806is fitted therein. In one embodiment, middle shaft808bis made of a single coiled shaft. The single coiled shaft can be wound on a mandrel such that there are gaps in between adjacent coils forming a coiled tubular structure. In other words, less tension is applied to a wire as it is being wound around the mandrel than would be applied to a wire in which no gaps are desired. The result is a coiled tubular structure which is less rigid and allows for ease of deflection of distal section804when deployed during a medical procedure. Within distal section804, tendon sheath814housing tendon816does not wrap around the mid shaft808bbut runs straight parallel to the longitudinal direction of the mid shaft, still captured with the mid shaft808band the outer shaft810b. The catheter deflects towards the radial direction of the location of the tendon sheath814. If only one tendon is used, the catheter only deflects in one direction.

As discussed previously, outer shaft810bcan serve as an outer housing for distal section804. In some embodiments, tendon sheath814housing tendon816can reside between middle shaft808band outer shaft810bof distal section804. In one embodiment, tendon sheath816can be fixed in a longitudinal position between middle shaft808band outer shaft810b. In some embodiments, tendon sheath816can be fixed by fusing the outer shaft810bto the mid shaft808bby heat. A tip anchor assembly818can be located at a distal end of distal section804. Tip anchor assembly818can be made of a metal such as stainless steel or a polymer such as Pebax®, polyimide, or PEEK. In one embodiment, tip anchor assembly818can be a soft polymer that is mounted at the distal end of distal section804to reduce trauma incurred as catheter800moves through the body. In some embodiments, distal ends of outer shaft810b, inner shaft806and tendon wire816can be fixed to tip anchor assembly818.

FIG. 8drepresents a front cross-section view of catheter800taken at lines D-D ofFIG. 8a. This cross-section is within distal section804. In this view, catheter800includes inner shaft806which is surrounded by middle shaft808bwhich in turn is surrounded by outer shaft810b. In one embodiment, middle shaft808bcan include a single coiled shaft (as described above) for ease of flexibility. Tendon816can be used to control the movement of distal section804when catheter800is deployed within, for example, a curved anatomical path. The flexible nature of distal section804allows for deflection when a pull force is applied to a proximal end of tendon816.

In one embodiment, catheter800includes a proximal hub (not shown) with an injection port. The injection port is connected to a needle lumen to allow fluid communication from the injection port to the needle lumen, thereby allowing the introduction of a bioagent from the injection port and into the needle lumen and then into the tissue penetrated by the distal tip of the needle. The proximal hub with the injection port may include a luer lock. In another embodiment catheter800may also include a self-seal valve and a flush port. The medical instrument, such as the needle, runs inside of the self-seal valve.

According to embodiments of the present invention, the construction and materials of catheter800allow for a controlled turning response of distal section804when a turning force is applied to proximal section802as illustrated inFIG. 8e.FIG. 8eillustrates a cross-section of catheter800disposed within aortic arch820. Aortic arch820has a curved anatomical configuration. When a pull force is applied to tendon816(represented by arrow826), distal section804deflects (represented by arrow828) toward treatment site822even though a preferred orientation of distal section804is naturally oriented 180 degrees from the illustrated position. The natural orientation is due to the laws of physics which dictate that distal section804would naturally orient along the natural curvature of aortic arch820absent the embodiments described of the present invention. The angle of deflection may be between about 75 degrees and about 150 degrees. Once positioned at treatment site822, a medical instrument such as a needle or a biopsy clamp824within a lumen of catheter800can be used to treat treatment site822.

A deflectable catheter assembly has been described. Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention. For example, certain embodiments in which the first, second and third catheters are not coaxial are also within the scope of the present invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.