Medical fluid delivery system

A medical fluid delivery system is provided including a steerable, guide catheter, a delivery catheter adapted for deployment at a targeted tissue site using the steerable guide catheter, the delivery catheter including a proximal port, a distal port, and a lumen extending between the proximal and distal ports; a distal fixation element coupled to the delivery catheter so as to position the distal port adjacent the targeted tissue site; and a flexible hollow needle adapted to be advanced through the delivery catheter lumen, the flexible needle including a tissue-piercing distal tip for extending from the distal port of the delivery catheter for advancement into the targeted tissue site and a proximal end for extending from the proximal port of the delivery catheter through which a medical fluid is delivered.

FIELD OF THE INVENTION

The present invention relates to medical devices for delivering a medical fluid to a targeted tissue site.

BACKGROUND OF THE INVENTION

Various genetic or cellular modification therapies for treating or repairing diseased or damaged tissue are in development. For example, the delivery of skeletal myoblasts into damaged myocardium may be an effective treatment for repairing myocardial scar tissue following an infarct. Locally effective doses of a pharmacologic, genetic, or biologic agent may be toxic when given systemically. Systemic delivery of cells may be ineffective at the damaged tissue site and may be an inefficient use of specially cultured or harvested cells. Therefore, it is desirable to provide a fluid-delivery device and method for delivering cells or another genetic or biologic agent locally at a targeted tissue site.

Drug-eluting leads are commercially available and used for delivering, for example, an anti-inflammatory agent at an implant site. Drug-eluting devices are generally limited to treating only a relatively small volume of tissue at a device-tissue interface. The pharmacological effect is in part limited by the kinetics of the drug leaving the device. Biologic and genetic agents may have a limited shelf life, requiring unique storage conditions such as refrigeration, and may not tolerate sterilization procedures. Therefore, it is not desirable to package a device having drug eluting capabilities with the biologic or genetic agent already incorporated therein. To take advantage of various genetic or cellular modification therapies, it is desirable to provide a delivery device that allows a pharmaceutical, genetic, or biologic agent to be delivered to a targeted site at a depth within the tissue to treat a volume of tissue.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a medical fluid delivery system and method for targeted delivery of cells or a biologic, genetic, or pharmaceutical agent, all of which are generically referred to herein as a “medical fluid”. The delivery system includes a steerable guide catheter having an open lumen for carrying a delivery catheter. The delivery catheter is provided with a fixation member for anchoring the distal end of the delivery catheter adjacent to a targeted tissue site. The fixation member is provided to allow rotational movement of the delivery catheter relative to the targeted tissue site while maintaining the distal end of the delivery catheter against or near the targeted tissue surface and restricting any lateral movement of the delivery catheter relative to the targeted tissue site. In one embodiment, the fixation member is provided as helix.

The delivery catheter further includes an open lumen extending between a proximal and distal port for carrying a flexible, retractable hollow needle having a tissue-piercing distal tip. The needle can be extended from the distal port into the targeted tissue for delivering a medical fluid. In one embodiment, the flexible retractable needle is extendable from a port located on the distal end of the delivery catheter. In another embodiment, the flexible, retractable needle is extendable from a port located on the side of the delivery catheter, near its distal end. In yet another embodiment, the fixation member is provided as a hollow member and the flexible, retractable needle is extendable from the hollow fixation member. Multiple flexible, retractable needles may be provided, which are each extendable from a separate distal port. A micro-catheter that is extendable from the needle may also be provided to allow medical fluid delivery to a tissue site located more remotely from the distal needle tip.

The flexible, retractable needle is provided with a pre-formed curve such that the needle may be inserted into the targeted tissue site in a direction away from the fixation member along a pathway that is substantially co-planar with the targeted tissue. Alternatively, the delivery catheter lumen carrying the flexible needle may be provided with a curve near the distal port such that the flexible needle is directed along a pathway away from the fixation member, substantially co-planar with the targeted tissue.

In a method for using the fluid delivery system, the guide catheter is advanced to a targeted tissue site. The delivery catheter is anchored at the tissue site using the fixation member such that lateral movement of the delivery catheter relative to the tissue site is restricted but rotation of the delivery catheter relative to the tissue site is possible. After anchoring the delivery catheter, the steerable, guide catheter may be removed. The flexible, retractable needle is extended a desired distance into the targeted tissue and a medical fluid is delivered. The flexible, retractable needle is retracted in either a continuous or discreet step-wise fashion allowing either continuous or discreet delivery of the medical fluid along the needle path as it is retracted.

After retracting the needle, the delivery catheter remains anchored at the tissue site but is rotated a desired degree. The flexible, retractable needle is re-extended to deliver the medical fluid along a new needle path extending into the targeted tissue at a different radial direction from the delivery catheter than the first needle path. This process of rotating the delivery catheter, extending the retractable needle along a radial path from the delivery catheter, delivering a medical fluid along the needle path in either a discreet or continuous manner, and retracting the needle back into the delivery catheter is repeated as many times as desired so as to treat a volume of tissue surrounding the delivery catheter anchoring site.

In one embodiment, the fluid delivery system further includes an electrode for use in making impedance measurements between the flexible, retractable needle and the electrode. Impedance measurements performed when the needle is in an extended position can be used to determine if the delivery catheter tip is canted relative to the targeted tissue surface.

DETAILED DESCRIPTION

FIG. 1is a plan view of a fluid delivery system for targeted delivery of a medical fluid. A steerable, guide catheter6is provided having an elongated body8with an open lumen extending between a proximal end20and a distal end22. A delivery catheter10extends through the open lumen of guide catheter6. Delivery catheter10is provided with a distal fixation member14for anchoring the distal end30of delivery catheter10adjacent to a targeted tissue site. Delivery catheter10has an open lumen extending between a proximal port33located at or near proximal end31and a distal port32at or near distal end30provided for carrying a hollow, flexible needle16used for medical fluid delivery. Flexible needle16is provided with a tissue-piercing tip17for entering a targeted tissue site for delivery of a medical fluid. The needle16can be advanced and retracted with respect to delivery catheter10by actuating the proximal needle end24. Needle16is fully retracted within the lumen of delivery catheter10as the guide catheter6is advanced to a targeted tissue site.

Guide catheter6is provided with a steering mechanism, which can include a manipulative handle28and an actuator, for example a pull wire26, used for maneuvering the distal end22for steering guide catheter6to a targeted tissue site. Guide catheter6may be advanced to a targeted site using image-guidance, which may rely on fluoroscopy or other imaging technologies. Alternatively, guide catheter6and delivery catheter10may be navigated to a targeted tissue site using any appropriate navigation or localization technology such as an image-guided navigation system or other medical device mapping or localization system. Reference is made, for example, to U.S. patent application Ser. No. 10/299,969, filed Nov. 19, 2002 to Hunter et al., and U.S. Pat. No. 5,983,126 issued to Wittkampf, both of which patents are incorporated herein by reference in their entirety. During advancement of guide catheter6to a targeted site, needle tip17is retracted within delivery catheter10, and delivery catheter10, including fixation member14, is retracted within guide catheter body6.

Upon reaching a targeted tissue site, the distal end30of delivery catheter10is anchored adjacent the targeted tissue by inserting fixation member14into the tissue. In an exemplary embodiment, fixation member14is provided as a helix such that, after anchoring delivery catheter10at a selected tissue site, delivery catheter10may be rotated relative to the tissue site but is restricted by the fixation member from moving in any lateral direction relative to the selected tissue site. The central axis of a helical fixation member14generally corresponds to the central axis of guide catheter8and delivery catheter10. Flexible needle16is provided with a tissue-piercing tip17that is advanced a desired distance into the targeted tissue. A medical fluid can then be delivered to the targeted tissue by injecting the medical fluid through proximal opening25of hollow needle16until a desired dosage exits distal needle tip17.

As will be described in greater detail below, delivery catheter10can be rotated with respect to the targeted tissue, without fully removing fixation member14from the tissue site, so that needle16may be advanced along multiple pathways extending in a generally radial direction from a single fixation site. Control of the delivery catheter rotation distance or angle may be achieved by fabricating delivery catheter10with a torsional stiffness that results in 1:1 matching of rotational movement between proximal end31and distal end30. The distance that needle tip17is advanced into a targeted tissue may be controlled by providing calibrated markings near proximal needle end24. Alternatively, rotational delivery catheter movement and needle tip advancement may be observed using medical imaging, such as fluoroscopy or measured using an a medical device mapping or localization system designed to sense rotational movement of the delivery catheter10about its central axis.

FIG. 2is a sectional view of the distal end of the fluid delivery system shown inFIG. 1. Delivery catheter10is shown extending from the distal opening18of an open lumen36at the distal end22of guide catheter body8. Delivery catheter10is provided with fixation member14and open lumen38for carrying flexible needle16. Needle16may be provided with a laterally extending face35for interfacing with a lateral stop34provided within delivery catheter lumen38. Lateral stop34limits the maximum distance that needle16may be extended from the distal port32of lumen38at the distal end30of delivery catheter10.

In the embodiment shown inFIG. 2, needle16is provided as a shape-memory or super-elastic material having a pre-formed curve or bend40near distal tip17. When needle16is retracted within lumen38, needle16will be held in a straight position. When needle16is extended out distal port32and is no longer constrained by the shape of lumen38, the native shape of needle16including curve40will be restored. Curve40will cause needle tip17to be extended in a direction away form fixation member14, along a pathway within the targeted tissue that becomes substantially co-planar with the targeted tissue. Needle16can be fabricated with a pre-formed, native curve or bend using a flexible, super-elastic material or shape memory material such as Nitinol.

Flexible needle16and delivery catheter10are designed to interact in a way that allows longitudinal advancement and retraction of needle16but prevents rotation of needle16relative to delivery catheter10so as to maintain the direction of advancement of needle tip17in a radial direction away from fixation member14. In one embodiment, flexible needle16is provided with a longitudinal groove37which interacts with a rotational stopping member39located along the inner diameter of delivery catheter lumen38. Other mechanisms for preventing rotational movement of needle16relative to delivery catheter10can be substituted.

A straight needle that travels straight into the targeted tissue and remains along a pathway substantially perpendicular to the tissue plane could be used, however, a medical fluid delivered into a perpendicular needle pathway has greater likelihood of leaking out of the tissue via the needle path. Greater retention of the injected fluid within the tissue volume may be achieved when the needle pathway is substantially within a plane of the tissue substantially co-planar with the tissue rather than perpendicular to it.

FIG. 3is a sectional view of the distal end of a fluid delivery system according to an alternative embodiment. Delivery catheter10extends from distal opening18of open lumen36of guide catheter8. Delivery catheter10is provided with an open lumen42for carrying needle16. Lumen42is formed with a curve44near distal port32. Needle16is shown in a partially extended position. In a fully extended position, lateral surface35will interface with lateral stop34of lumen42. Other retraction or advancement stop mechanisms may be incorporated in delivery catheter10for controlling the maximum distance that needle16is retracted or advanced relative to delivery catheter10.

Needle16is provided as a straight or pre-formed curved, flexible, hollow needle that follows an angled pathway into targeted tissue as dictated by the geometry of curve44. Curve44is designed to cause needle16to be directed away from fixation member14and enter the targeted tissue at an angle such that needle tip17follows a pathway that becomes substantially coplanar with the targeted tissue as needle16is advanced. Needle16may be fabricated from stainless steel or any other material that provides the lateral flexibility needed to follow the curved course of lumen42yet provides the longitudinal stiffness needed for insertion of needle tip17into a targeted tissue.

FIG. 4is a sectional view of the distal end of a fluid delivery system provided according to another embodiment of the present invention. Delivery catheter10is provided with a distal port48located on the side of delivery catheter body11near distal end30. Open lumen46for carrying needle16terminates at side port48such that needle16exits delivery catheter10from side port48rather than from a port provided on distal end30as shown inFIGS. 2 and 3. Needle16may be provided as a flexible, straight needle that follows an angled pathway into a targeted tissue as dictated by curve47formed in lumen46. Alternatively or additionally, needle16may be provided as a flexible, needle with a pre-formed distal curve near tip17.

In any of the embodiments shown inFIGS. 2,3and4, a flexible microcatheter50may be provided extending through the length of needle16. Microcatheter50can be extended through distal needle tip17such that a medical fluid may be delivered through microcatheter50into tissue located remotely from needle tip17. The distance that the microcatheter50is advanced can be controlled by visualizing the microcatheter50using medical imaging, such as fluoroscopy. The microcatheter50may also be provided with calibrated markings at its distal or proximal end to allow measurement of the distance microcatheter50is advanced. Microcatheter50may be embodied as a flexible, hollow needle having a diameter smaller than needle16such that it may be advanced through the lumen of needle16. In some embodiments, microcatheter50may be constructed as a composite of a series of tubular elements, for example as generally disclosed in U.S. Pat. No. 6,306,124, issued to Jones, et al., hereby incorporated herein by reference in its entirety.FIG. 5is a sectional view of a fluid delivery catheter according to yet another embodiment of the present invention. Delivery catheter10is provided with a lumen54extending to a distal port56that is aligned with a lumen58included in a hollow, helical fixation member52. Fixation member52is fixedly coupled to delivery catheter10such that delivery catheter lumen54and fixation member lumen58provide a continuous course through which flexible needle16may be advanced. Needle tip17can be extended through a distal port59at the distal end of the fixation member52into a targeted tissue after fixation member52is anchored at a targeted tissue site. The helical shape of fixation member52will direct needle tip17along a pathway away from fixation member52that is substantially co-planar with the targeted tissue. The pitch and inner diameter of hollow fixation member52are designed large enough to allow smooth advancement of flexible needle16. Hollow fixation member52may be provided with a low-friction surface or coating on the inner surface that forms lumen58to promote smooth advancement of needle16. A microcatheter extendable from needle16through tip17as described above can also be included in the delivery catheter shown inFIG. 5.

FIG. 6is an illustration of one example of a fluid delivery pattern that can be achieved using a fluid delivery system provided by the present invention. Fixation site60is an anchoring site at a targeted tissue location in which the delivery catheter fixation member is secured. For example, site60may be approximately the center of a myocardial infarct that is to be treated by injecting myoblasts into the infarct area. The flexible hollow needle is extended from the delivery catheter along a needle pathway62a desired distance into the tissue. The view shown inFIG. 6is looking down onto the tissue such that the plane of the paper is the plane of the myocardial tissue. The needle pathways extending from fixation site60are substantially co-planar with the myocardial tissue.

As the needle is retracted, the medical fluid is injected into the tissue. The medical fluid may be delivered at a controlled, continuous injection rate as the needle is retracted at a continuous or discontinuous rate. Alternatively the needle can be retracted discreet distances along needle pathway62with bolus injections of the medical fluid delivered at injection sites64at each discreet distance.

After injecting the medical fluid along pathway62, the needle is fully retracted into the delivery catheter, and the delivery catheter is rotated. The delivery catheter is rotated a desired distance or angle66relative to the targeted tissue without fully removing the fixation member from the fixation site60. The needle can then be advanced into the tissue a desired distance along a new needle pathway68. During retraction of the needle, the medical fluid is injected continuously or at discreet injection sites70.

These steps of advancing the needle a desired direction from the fixation site60, injecting the medical fluid, retracting the needle back into the delivery catheter, and rotating the delivery catheter to allow needle advancement along a new pathway extending radially from fixation site60can be repeated as many times as desired. In the example illustrated inFIG. 6, the needle is advanced along8pathways (solid lines) radiating from the fixation site60at approximately45degree rotations. The medical fluid is injected at multiple sites (shown by solid circles) along each pathway. The solid circles used to indicate possible injection sites inFIG. 6are not intended to reflect the scale of the treated tissue volume at each injection site as the distribution of the fluid will depend on the properties of both the tissue and the administered fluid.

A relatively large volume of tissue surrounding the fixation site60can thus be treated with a medical fluid without removing and relocating the delivery catheter. The fluid delivery system and method described in conjunction withFIG. 6allows controlled delivery of a medical fluid within a targeted volume of tissue. The distances between delivery sites can be controlled by the controlled advancement and retracting of the needle and the rotation of the delivery catheter.

FIG. 6is one example of a continuum of possible medical fluid delivery patterns wherein a medical fluid is delivered continuously or at one or more discreet sites located along one or more pathways extending outward from a fixation site. In order to deliver the medical fluid at sites further than the maximum distance that the needle may be advanced, a microcatheter may be advanced through the needle (as illustrated inFIG. 4), to reach tissue located remotely from the fully advanced needle tip.

FIG. 7is a perspective view of a delivery catheter having multiple lumens for carrying one or more flexible, retractable needles. In some embodiments, the delivery catheter may be provided with multiple needles carried individually in multiple lumens, or a single open lumen large enough to accommodate multiple needles. The multiple needles extend from separate distal ports such that they may be advanced into a targeted tissue in different radial directions away from the distal fixation member.

In the example shown inFIG. 7, two needles80and84extend from two separate distal side ports87and88of delivery catheter76. Fixation member78can be provided as a retractable helix which is extended when delivery catheter76is positioned against a targeted tissue site. Fixation member78is extended from an opening77at the distal end of catheter76and anchored in the targeted tissue. Methods for implementing a retractable fixation helix are known in the art. A retractable fixation helix may be provided as generally disclosed in U.S. Pat. No. 4,106,512 issued to Bisping or as generally described in U.S. Pat. No. 6,813,521 issued to Bischoff et al., both of which patents are incorporated herein by reference in their entirety.

After securing fixation member78at a targeted site, needles80and84can be extended from distal side ports87and88and advanced into the targeted tissue. Microcatheters100and102are shown extending from the distal tips82and86of respective needles80and84. Microcatheters may be used to deliver the medical fluid into tissue located remotely from needle tips82and86. The medical fluid can be delivered along two pathways corresponding to advancing needle80and needle84simultaneously or sequentially, prior to rotating delivery catheter76. Delivery catheter76may then be rotated with respect to the targeted tissue site such that needles80and84can be inserted into the targeted tissue along two new pathways.

FIG. 8is a sectional view of one embodiment of a multi-lumen delivery catheter provided with multiple needles for injecting a medical fluid into a targeted tissue. A multi-lumen delivery catheter110may be provided with a splined, multi-lumen body as generally disclosed in U.S. Pat. Appl. Pub. No. 2004/0097965, by Gardeski et al., hereby incorporated herein by reference in its entirety. The elongated delivery catheter body includes an outer body member112having inward-radiating splines that mate with outward-radiating splines provided on an inner body member114so as to form multiple lumens116athrough116fbetween sets of mated splines. Flexible needles120,122, and124are shown in lumens116a,116c, and116e. Any or all of lumens116athrough116fmay be used for carrying flexible, hollow needles that may be advanced and retracted within lumens116athrough116fso as to extend the needles out the distal end of the delivery catheter body to insert them into a targeted tissue site for medical fluid delivery and then retract the needles back into the catheter body during rotation or removal of the delivery catheter110. Any remaining lumens of delivery catheter110not used for carrying a fluid delivery needle could be used for carrying conductors associated with distal sensors or electrodes or for carrying any other suitable medical devices or components.

Fixation member132may be coupled to the distal end of the inner member114or may be provided as a retractable fixation member housed within a central lumen130of inner member114. The central lumen130could be counterbored at the distal end of the catheter110to allow a robust fixation helix132to be retracted into inner member114.

FIG. 9is an open, perspective view of the multi-lumen delivery catheter shown inFIG. 8. Outer splined body member112is mated with inner splined body member114to form multiple lumens. Flexible needles120,122and124may be advanced through respective lumens to extend from respective distal ports at distal end136of the delivery catheter110. In an alternative embodiment, outer member112may be provided with side ports near distal end136to allow flexible needles120,122, and124to exit the catheter body via the side ports. Flexible needles120,122, and124are provided with a pre-formed curve near the distal needle tips such that the distal tips of needles120,122, and124are directed away from fixation member132, along a pathway that becomes substantially co-planar with the targeted tissue as the needles120,122, and124are advanced.

FIG. 10shows a delivery catheter fixed at a targeted tissue site and illustrates one method for verifying the position of the delivery catheter with respect to the tissue surface. Distal end77of delivery catheter76is positioned against the surface92of a targeted tissue94. Fixation member78is anchored into tissue94. Delivery catheter76is provided with two side ports87and88through which two flexible needles80and84are extended into a targeted tissue94.

It is desirable to advance flexible needles80and84along pathways that are substantially co-planar with tissue94rather than substantially perpendicular to tissue surface92. In order to advance needle tips82and86along a pathway that is co-planar with the targeted tissue94, distal catheter end77should be positioned perpendicular against tissue surface92and not in a canted position as illustrated inFIG. 10. In the canted position shown, advancement of needle84into tissue94results in a needle pathway98substantially perpendicular to tissue surface92. Needle80, which enters tissue surface92at an angle, will follow a pathway97that is substantially planar with the tissue94but is at a shallow depth within the tissue94.

In order to determine if the distal end77of delivery catheter76is canted relative to tissue surface92an impedance measurement can be made. As such, delivery catheter76is provided with one or more electrodes90and96. Electrodes90and96are coupled to separate, insulated conductors extending to the proximal end of delivery catheter76. In an alternative embodiment, fixation member78may function as an electrode for impedance measurements, in which case fixation member78would be coupled to a conductor extending to the proximal end of delivery catheter76.

In one embodiment, delivery catheter76is used for delivering a medical fluid to myocardial tissue from an endocardial surface. As such, needles80and84will extend from side ports87and88, through the intracardiac blood volume, and into the myocardial tissue94. An impedance measurement made between needle84and electrode90will be relatively higher than an impedance measurement made between needle80and electrode90due to relatively less surface area exposure of needle84to the intra-cardiac blood volume.

In one method for using impedance measurements to verify the position of delivery catheter76relative to the tissue surface92, two impedance measurements are made using two flexible needles80and84extended from delivery catheter76and a common electrode,90or96. If the two impedance measurements are approximately equal, the distal end77of delivery catheter76is not canted relative to tissue surface92. If the two impedance measurements are not substantially equal, the delivery catheter distal end77is canted with respect to tissue surface92. The difference in impedance measurements arises from differing surface areas of needles80and84exposed to the intra-cardiac blood volume. Needles80and84may be retracted, and adjustment of the delivery catheter position may be made.

In another embodiment, impedance measurements may be made using one needle. The needle may be advanced into the targeted tissue and an impedance measurement made between the needle and an electrode. This impedance measurement may be compared to an expected impedance range. If the impedance measurement is outside an expected impedance range, the distal end77is canted with respect to tissue surface92. A higher or lower than expected impedance measurement results when the needle surface area exposure to the intracardiac blood volume is greater or less than the surface area exposure that occurs when distal end77is not canted with respect to tissue surface92.

In yet another embodiment, an impedance measurement made between one flexible needle and an electrode when the needle is extended in one direction from catheter76is compared to a second impedance measurement made between the same flexible needle and electrode when the needle is extending in a different direction from delivery catheter76after rotating catheter76. If the two measurements are substantially equal, the surface area of the needle exposed to the blood volume is approximately equal in both positions indicating that distal end77is not canted relative to tissue surface92. If the two measurements are substantially unequal, the distal end77of delivery catheter76is canted with respect to tissue surface92. The needle can be retracted to allow adjustment of catheter76position.

FIG. 11shows a delivery catheter76positioned perpendicularly against a targeted tissue surface. Flexible needles80and84enter tissue surface92at similar angles. The flexible needles80and84are fabricated with a pre-formed curve and/or are advanced through a curved lumen designed to direct the needles80and84along a pathway95and99, respectively, that is approximately co-planar with the tissue94. Impedance measurements made between needle84and electrode90and needle80and electrode90will be similar since similar surface areas of needles80and84are exposed to the intra-cardiac blood volume when the needle tips82and86are extended into the endocardial surface92of myocardial tissue94.

FIG. 12shows a delivery catheter fixed at a targeted tissue site and illustrates a method for verifying the position of the hollow flexible needles80and84within the targeted tissue. Needles80and84are formed from a conductive material and are provided with insulative coating83and85, respectively. For example, needles80and84may be formed from stainless steel provided with a non-conductive polymer coating, such as polyimide, a heat-shrinkable polyester, or paralyne. The insulative coating83and85insulates at least the portion of the respective needles80and84that is expected to be exposed to non-targeted tissue or body fluid when the needles80and84are advanced from delivery catheter76. A distal portion of needles80and84near and including needle tips82and86is not insulated. An impedance measurement may then be made between needle tips82and86to verify that the needles80and84are properly inserted into the targeted tissue. Alternatively, an impedance measurement may be made between one needle tip82or86and fixation member78, or electrode90for verifying that the needle tip82or86is properly inserted into the targeted tissue. The use of an impedance measurement between a needle tip and the fixation member or an electrode can be employed with fluid delivery systems having a single flexible needle.

FIG. 13is a sectional view of the distal portion of an alternative embodiment of a fluid delivery system in accordance with the invention. The system includes steerable guide catheter8used for guiding delivery catheter108to a targeted tissue site. Delivery catheter108is provided with a central lumen110extending from the proximal delivery catheter end to distal end120. Central lumen110is provided for carrying the elongated body112of fixation member106. Fixation member106is provided with a tissue piercing distal end114which is typically formed into a helix to allow fixation member106to be rotated and thereby fixed into a targeted tissue site at distal end114. The helical distal end114extends from central lumen opening116of delivery catheter108and is generally greater in diameter than lumen110such that the distal end114remains extended from lumen opening116. Distal end114is fixed into a targeted tissue site by rotating the proximal end of elongated body112. The proximal end of elongated body112may be provided with a handle (not shown) to facilitate rotation of fixation member106.

Delivery catheter108is further provided with a needle lumen118extending from the delivery catheter proximal end to the delivery catheter distal end120. Flexible hollow needle124extends through needle lumen118such that tissue piercing distal tip126can be advanced out distal opening122of needle lumen118into a targeted tissue. Distal opening122is shown on the distal end120of delivery catheter108. Distal opening122may alternatively be provided on the side of delivery catheter108, near but proximally to distal end120. Needle124is provided with a preformed curve in the vicinity of distal tip126such that as tip126is advanced into a targeted tissue, it is directed away from fixation member distal end114and follows a needle path substantially within a plane of the targeted tissue.

After administering a fluid along a needle pathway, needle124can be retracted within lumen118, delivery catheter108rotated with respect to fixation member106while fixation member106remains fixed in the targeted tissue, and needle124extended into the targeted tissue along a new pathway extending radially away from fixation member distal end114. As such, delivery catheter108and fixation member106can be rotated independently from each other. By maintaining delivery catheter distal end120against the surface of the targeted tissue, a medical fluid can be delivered along multiple needle pathways at a similar depth within the tissue when fixation member106remains fixed in the targeted tissue.

Thus, a fluid delivery device has been described according to detailed, exemplary embodiments provided herein. The detailed descriptions are intended to illustrate various embodiments for practicing the invention and are not to be interpreted as limiting with regard to the following claims.