US20060129132A1 - Deflectable telescoping guide catheter - Google Patents

Abstract

A catheter employs an inner guide with a pre-formed distal tip, an outer guide with a predetermined deflection location, and a proximal actuator. The inner guide can be longitudinally extended and axially rotated relative to the outer guide. The proximal actuator can adjustably change a bend angle of the predetermined deflection location. The catheter can be deployed with the inner guide retracted inside the distal end of the outer catheter. The extensible and rotatable inner catheter can be combined with the adjustable bend angle of the outer guide to provide an improved system for accessing and cannulating venous structures.

Description

RELATED APPLICATIONS
• This is a divisional of U.S. patent application Ser. No. 10/431,788, filed on May 8, 2003, which is a divisional of U.S. patent Ser. No. 10/014,735 filed on Dec. 11, 2001, now U.S. Pat. No. 6,755,812, to which Applicant claims priority under 35 U.S.C. § 120, and which are incorporated herein by reference.
FIELD OF THE INVENTION
• The invention relates generally to guide catheters, and more particularly to steerable, telescoping guide catheters used to locate and cannulate the coronary sinus of a patient's heart.
BACKGROUND OF THE INVENTION
• Guiding catheters are instruments that allow a physician to access and cannulate vessels in a patient's heart for conducting various medical procedures, including venography and implanting of cardiac pacing devices. Cannulating heart vessels requires navigating a small diameter, flexible guide through the tortuous vasculature into a heart chamber, and then into a destination heart vessel. Once the destination heart vessel is reached, the catheter acts as a conduit for insertion of payloads into the vessel.
• A commonly accessed destination vessel for cardiac pacing lead insertion is the coronary sinus. A pre-shaped guiding catheter is typically used to blindly locate the coronary sinus ostium. This endeavor, however, is complicated by the fact that the location of the coronary sinus ostium may vary appreciably from one patient to another, especially among patients with diseased hearts. Oftentimes, the clinician is entirely unable to locate the coronary sinus ostium using the guiding catheter, and must resort to finding the ostium by “mapping” (interpreting localized bipolar waveforms) using an electrophysiological (EP) catheter and an ECG monitor. After the ostium is located, the guiding catheter is typically used to inject radiographic contrast media into the coronary sinus to highlight the associated venous system, and then a pacing lead is installed within one of the coronary branches.
• Complicating this scenario is the dynamic structural deformation of the heart chambers that occurs from normal cardiac activity during the procedure. This further increases the difficulty of guiding a catheter to its destination. Presently, a considerable amount of time is often spent by the physician when manipulating such catheters within cardiac structures, such as the right atrium, simply trying to locate an anatomical feature of interest, such as the coronary sinus ostium.
• Guiding catheter systems are typically configured with a profile that is optimized for the intended method of access. In the case of accessing the coronary sinus via the right atrium, a catheter with a distal contour including a relatively sharp bend will point the catheter towards the likely location of the coronary sinus once the right atrium is reached. The contours of pre-shaped guiding catheters are generally fixed, and this is typically achieved in production by constraining the distal end within a shaping fixture while warming them until they assume the intended shape (i.e., by “heat setting” their polymer shaft).
• Guiding catheters are sometimes introduced over a pre-shaped guide wire that is inserted into the desired location first. The guide wire is typically small and maneuverable, and can be pre-shaped for the desired venous path. However, utilizing a guide wire prior to introducing the guide catheter is more time consuming as two operations are required. Shortening the time required to cannulate the desired vessels is desirable as it reduces the total procedure time and reduces trauma to the patient.
• There is a need for an improved guide catheter having enhanced maneuvering capabilities for accessing blood vessels of interest and for cannulating those vessels. There exists a further need for a guiding catheter that accounts for anatomical variation and defects with the destination structures. The present invention fulfills these and other needs, and addresses other deficiencies of prior art implementations and techniques.
SUMMARY OF THE INVENTION
• The present invention is directed to a guide catheter employing a telescoping inner guide and a deflectable outer guide. According to one embodiment of the present invention, the catheter includes an outer guide having a distal end, a proximal end, and a predetermined deflection location proximate the distal end. An inner guide section having an inner guide lumen and a pre-formed distal end is movably disposed within the outer guide. The inner guide section is displaceable beyond the distal end of the outer guide. An actuator mechanism located at the proximal end of the catheter changes a bend angle at the predetermined deflection location of the outer guide. The proximal end of the inner guide is accessible at the proximal end of the catheter allowing adjustable axial displacement of the pre-formed distal end of the inner guide relative to the outer guide.
• In accordance with another embodiment, a catheter includes an outer guide comprising an outer guide lumen, a distal end, a proximal end, a predetermined deflection location proximal to the distal end, and a deflection member coupled to the outer guide distal to the predetermined deflection location. The catheter also includes an inner guide comprising an inner guide lumen, a pre-formed distal end, and a proximal end. In certain configurations, the inner guide lumen may be dimensioned to receive a cardiac lead, such as a cardiac pacing lead. The inner guide is movable within the outer guide lumen and displaceable beyond the distal end of the outer guide. An actuator mechanism is located at a proximal end of the catheter and coupled to the deflection member. The actuator mechanism is configured to change a bend angle at the predetermined deflection location of the outer guide in response to a proximally directed force applied to the deflection member. The proximal end of the inner guide is accessible at the proximal end of the catheter permitting adjustable axial displacement of the pre-formed distal end of the inner guide relative to the distal end of the outer guide.
• In one configuration of the catheter, the inner guide can be axially displaced beyond the distal end of the outer guide within a range of 0 to about 20 centimeters. For example, at least 2 centimeters of the inner guide can be axially displaced beyond the distal end of the outer guide.
• The pre-formed distal end of the inner guide may be configured to be deformable, such that the inner guide is retractable within the distal end of the outer guide. In one configuration, the inner guide is substantially more flexible than the outer guide, such that the distal end of the inner guide assumes the shape of the outer guide when the inner guide is retracted.
• The bend angle at the predetermined deflection location of the outer guide can be defined relative to a longitudinal axis of the outer guide proximal to the predetermined deflection location. In one configuration, the bend angle can be adjustable from a minimum of about 0 degrees to a maximum of about 150 degrees.
• A bend radius of the predetermined deflection location can be defined relative to a centerline of the predetermined deflection location. The bend radius is greater than about six times an outer diameter of the outer guide.
• The inner guide is arranged such that axial forces exerted on the proximal end of the inner guide can extend and retract the pre-formed distal end of the inner guide relative to the distal end of the outer guide.
• In one configuration, the catheter further includes at least one steering tendon connected to the inner guide proximate to the pre-formed distal end. The proximal actuator mechanism can produce a tensile force acting on the steering tendon(s). The tensile force acting on the steering tendon(s) imparts a change in the bend angle at the predetermined deflection location of the outer guide.
• In another configuration, the catheter further includes at least one steering tendon connected to the outer guide proximate to the distal end. The actuator mechanism produces a tensile force acting on the steering tendon(s). The tensile force acting on the steering tendon(s) imparts a change in the bend angle at the predetermined deflection location of the outer guide.
• The catheter may be configured such that an axial rotational force imparted on the proximal end of the outer guide rotates the pre-formed distal end of the inner guide. In one configuration of the invention, the catheter further includes a seal between the inner guide and the outer guide. The seal is typically located at the proximal end of the catheter.
• According to a further embodiment of the present invention, the catheter further includes an occlusion balloon affixed to the distal end of the outer guide.
• In one configuration, for example, the catheter further includes at least one electrode located proximate the pre-formed distal end of the inner guide. One or more electrical conductors can be coupled to the electrode(s) and extend through at least one of the inner and outer guide lumens to a proximal section of the catheter.
• According to a further embodiment of the present invention, the catheter includes a plurality of band electrodes disposed at the distal end of at least one of the inner and outer guides. One or more electrical conductors can be coupled to the band electrode(s) and extend through at least one of the inner and outer guide lumens to a proximal section of the catheter.
• According to another embodiment of the present invention, a method of inserting a payload into a coronary sinus of a patient's heart involves providing a catheter having an outer guide, an inner guide and an actuator mechanism. The outer guide includes an outer guide lumen, a distal end, a proximal end, and a predetermined deflection location proximate the distal end. The inner includes an inner guide lumen, a pre-formed distal end, and a proximal end. The inner guide is movable within the outer guide lumen and displaceable beyond the distal end of the outer guide. The actuator mechanism is located at a proximal end of the catheter. The actuator mechanism changes a bend angle at the predetermined deflection location of the outer guide. The proximal end of the inner guide is accessible at the proximal end of the catheter, allowing adjustable axial displacement of the pre-formed distal end of the inner guide relative to the distal end of the outer guide.
• The method further involves inserting the distal end of the catheter through a patient's right atrium via an access vessel. The inner guide is distally displaced beyond the distal tip of the outer guide and the bend angle is changed at the predetermined deflection location via the actuator mechanism to direct the pre-formed distal end of the inner guide for finding and cannulating the patient's coronary sinus. The outer guide is distally advanced over the inner guide to seat the outer guide in the patient's coronary sinus. The inner guide is proximally retracted to remove the inner guide from the catheter. The payload is advanced through the proximal end of the outer guide such that the payload is inserted into the patient's coronary sinus. In one aspect of the method, the payload includes a cardiac pacing lead.
• According to yet another embodiment of the present invention, a method of inserting a payload into a coronary sinus of a patient's heart involves inserting the distal end of the catheter through a patient's right atrium via an access vessel. The inner guide is distally displaced beyond the distal tip of the outer guide and the bend angle is changed at the predetermined deflection location via the actuator mechanism to direct the pre-formed distal end of the inner guide for finding and cannulating the patient's coronary sinus. The payload is advanced through the proximal end of the inner guide such that the payload is inserted into the patient's coronary sinus. In one aspect of the method, the payload includes a cardiac pacing lead.
• The above summary of the present invention is not intended to describe each embodiment or every implementation of the present invention. Advantages and attainments, together with a more complete understanding of the invention, will become apparent and appreciated by referring to the following detailed description and claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1A is a cut-away view of a patient's heart, showing a catheter embodying features of the present invention deployed within the heart;
• FIG. 1B is an external view of a catheter embodying features of the present invention;
• FIG. 1C is an axial cross section1-1 fromFIG. 1B showing the distal end of an outer guide;
• FIG. 2A is a view of the distal end of the catheter showing adjustable bend angle of the preformed location on the outer guide;
• FIG. 2B is a view of the distal end of the catheter showing varying bend radii of the preformed location on the outer guide;
• FIG. 3A is a view of the distal end of the catheter showing extension and retraction of an inner guide;
• FIG. 3B is a cutaway view of the distal tip of the catheter illustrating the inner guide fully retracted within the outer guide;
• FIG. 4A is a cross sectional view of an embodiment of an actuator mechanism of the guide catheter;
• FIG. 4B is a view of the distal end of the catheter showing end electrodes and band electrodes provided at the distal ends of the inner guide;
• FIG. 4C is a view of the distal end of the catheter showing end electrodes and band electrodes provided at the distal ends of the inner and outer guides;
• FIG. 5 is a view of the distal end of the catheter showing a steering attachment and an occlusion balloon;
• FIG. 6A is an external view of the catheter showing pacing lead delivery from the outer guide after the inner guide has been removed; and
• FIG. 6B is an external view of the catheter showing pacing lead delivery from the inner guide.
• While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail herein. It is to be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE VARIOUS EMBODIMENTS
• In the following description of the illustrated embodiments, references are made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration, various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized, and structural and functional changes may be made without departing from the scope of the present invention.
• With reference toFIG. 1A, a distal end of acatheter100 is illustrated in accordance with an embodiment of the present invention. Thecatheter100 includes anouter guide101 and aninner guide104. Thecatheter100 is shown deployed within a patient's heart, accessing the coronary via the right atrium. A distal end of theinner guide104 extends from theouter guide101 as theinner guide104 is advanced towards the coronary sinus ostium.
• Turning now toFIGS. 1B and 1C, features of acatheter100 accordance with an embodiment of the present invention are detailed. Thecatheter100 includes anouter guide101. Theouter guide101 is configured as an elongated, flexible shaft with a centrally disposedopen lumen103. Thecatheter100 further includes aninner guide104 that can be configured as an elongated flexible shaft with a central open lumen. Theinner guide104 is movably disposed within theopen lumen103 of theouter guide101. The distal end of theinner guide104 is shown inFIG. 1B extending beyond thedistal tip111 of theouter guide101. Theinner guide104 can longitudinally extend and retract relative to thedistal tip111 of theouter guide101.
• Theouter guide101 includes adeflection location102 at a distal section of theouter guide101. Anactuator107 allows selectable shaping of thedeflection location102. Thedeflection location102 is advantageously located at a predetermined distance from thedistal tip111 of the outer guide to assist in navigation of thecatheter100. Once theouter guide101 enters an access chamber (the right atrium of the heart, for example) thedistal tip110 of theinner guide104 can be deflected by shaping thedeflection location102. Theinner guide104 advantageously includes a pre-shapeddistal end116 providing an optimized geometry for locating specific vascular features (the coronary sinus ostium, for example). As shown inFIG. 1B, the pre-shapeddistal end116 includes acurve106.
• A combination of the pre-shapeddistal end116, the extensibility of theinner guide104, and/or the adjustability of theouter guide101 atdeflection location102 provides an improved and flexible system for maneuvering the guide catheter within the venous system and constricted cardiac structures.
• The maneuvering features of the present invention serve to reduce procedure time for finding and cannulating desired vessels. By way of example, one such procedure involves inserting theouter guide101 through a percutaneous access vessel, such as the left cephalic vein. At this stage, theinner guide104 may be retracted within theouter guide101, such that the pre-shapeddistal end116 of theinner guide104 is within theouter guide101. Thedistal end116 of theouter guide101 is advanced to an access chamber, such as the right atrium.
• Once theouter guide101 has successfully reached an access chamber, theinner guide104 is then extended. Extension of theinner guide104 and adjustment of the outerguide deflection location102 can be used in combination to navigate thedistal tip110 of theinner guide104 to the vessel of interest.
• In one embodiment, once the vessel is located, theouter guide101 may be distally advanced over theinner guide104 to seat theouter guide101 in the subject vessel. In this embodiment, theinner guide104 can then be proximally retracted until it is removed from thecatheter100, leaving the largerouter guide lumen103 available for delivering a payload, such as a pacing lead, into the vessel of interest. In another embodiment, theinner guide104 is left seated in the vessel of interest and a payload can be advanced through theinner guide104 to the vessel of interest.
• Although thecatheter100 of the present invention as described herein can be used for introducing pacing leads into heart vessels, there are other uses to which thecatheter100 may be adapted. For example, once the coronary sinus ostium is cannulated, an injection of a radioopaque dye may be delivered through thecatheter100 for purposes of mapping venous structures. During dye injection, blood flow in the vessel may require occlusion. An occlusion balloon pre-installed on a distal section of thecatheter100 may be used to occlude blood flow. Also, the catheter may include distally mounted electrodes for obtaining ECG readings.
• Various features of a catheter in accordance with the present invention will now be described in greater detail, starting with theouter guide101. In one embodiment, the cross sectional shape of theouter guide101 is substantially annular with an outer diameter between about 5 French and about 10 French. The length of theouter guide101 can range from about 25 to about 75 centimeters. For purposes of cannulating the coronary sinus through the right atrium via the superior vena cava, for example outer guide lengths from about 35 to about 55 centimeters suffice for accessing many cardiac features of interest via this pathway.
• Theouter guide101 typically has sufficient flexibility to allow a clinician to navigate convoluted vasculature, with theguide101 still having sufficient axial stiffness to be pushed from the proximal end to an internal destination. Theouter guide101 may be fabricated from extruded polymeric tubing. To achieve superior axial stiffness, a tubing with multi-layer walls is desirable. In one embodiment, and as shown inFIG. 1C, the outer guide layers include a smooth elastomeric casing114 (e.g. high durometer Pebax), astainless steel braid115, and an innerlubricious lining112 formed, for example, from PTFE. The stainless steel braid stiffens the proximal portion of theouter guide101 so theouter guide101 minimally deflects under normal axial loads. In one particular embodiment, the distal section of theouter guide101 has greater flexibility than the proximal end, with a transition in flexibility occurring near the preformeddeflection location102. Such an outer guide design can employ any combination of varying geometry (diameter, wall thickness) and/or varying wall materials to accomplish a desired change in flexibility at thedeflection location102.
• As is further shown inFIG. 1C, theouter guide101 further includes asteering mechanism109 to control the shape of thedeflection location102.FIG. 1C is a cross sectional view of the catheter ofFIG. 1B further showing asteering tendon109 disposed within an extrudedcavity113 within the wall of theouter guide101. Thesteering tendon109 shown inFIG. 1C is configured as a circular wire, although any elongated, tensile load bearing member with a given cross sectional shape can perform this function, such as a ribbon with an elongated rectangular profile for example.
• Embedding thetendon109 in the extrudedcavity113 advantageously provides a conduit for radially restraining thetendon109 along the catheter length, yet allows thetendon109 to freely travel longitudinally. Further, the extrudedcavity113 for containing thetendon109 allows the inner and outer surfaces of theouter guide101 to remain relatively smooth.
• Alternative configurations may includetendons109 movably disposed within theouter guide lumen103, and such configurations are feasible given sufficient geometric clearances. Various alternative methods of disposing asteering member109 within catheter lumens are known in the art.
• In other embodiments, a number ofsteering tendons109 can be disposed as previously described, allowing for any combination of greater tendon tensile strength, tendon redundancy, and/or multiple deflection modes of the pre-formeddistal end117.
• Turning now toFIG. 2A, a deflection action of theouter guide101 at the catheter's distal end is illustrated. Theouter guide101 deflection includes anadjustable bend angle201. Theangle201 is shown measured between the undeformed centerlines of theouter guide101 both proximal and distal to thepredetermined location102. The undeformed centerlines are representative features of theouter guide101 and are derived by assuming the flexibleouter guide101 is held substantially straight proximally and distally to thepredetermined deflection location102, and forming a line through the cross sectional centroid of theouter guide101.
• The action of thesteering tendon109 is such that applying a tensile force to the proximal end of thetendon109 causes an increasedbend angle201. Releasing the tensile force from the steering tendon causes a decreasedbend angle202. The new shape of the catheter's distal end resulting from bend angles201 and202 are shown inFIG. 2A with solid and phantom lines, respectively.
• It will be apparent to those skilled in the art that thepredetermined deflection location102 can be formed by selecting an appropriate steering attachment point on theouter guide101 distal to thedeflection location102, as is best shown inFIG. 5, and creating one or more structural features at thedeflection location102. For example, such structural features can include, alone or in combination, a pre-shaped bend, a guide wall pre-stress, or an abrupt change in outer guide stiffness. The optimal structural feature to be used will depend on the composition of theouter guide101 and the allowable deformation of a transverse cross section at thedeflection location102.
• The shape of thepredetermined deflection location102 when no axial force is applied to the steering tendon is chosen based on expected venous pathways to be accessed by acatheter100 implemented in accordance with the principles of the present invention. In certain circumstances, it may be desirable for thedistal end117 of theouter guide101 to remain substantially straight (corresponding to zero degrees bend angle) at thedeflection location102 until thesteering tendon109 is activated.
• In one embodiment, thedeflection location102 includes a preformed bend formed to correspond to a known venous pathway, and advantageously requires only minimal adjustments of thesteering tendon109 to account for varying anatomy or other structural anomalies. In such a case, thedeflection location102 can be defined by an initial bend angle and an initial bend radius. In various useful embodiments, the initial bend angle can range from about 0 to about 90 degrees. In cases where the bend angle is greater than 0 degrees, the initial bend radius is preferably greater than about six times an outer diameter of theouter guide101. The preferred range of adjustment of theouter guide101 bend angle is from 0 to about 150 degrees.
• With respect toFIG. 2B, an illustration of preformed bend radii at thedeflection location102 is shown.Bend radius203 is smaller thanbend radius204, both bend radii inFIG. 2B corresponding to approximately the same bend angle. The shapes of theouter guide101 with respect to bendradii203 and204 are shown in solid and phantom lines, respectively. The bend radii203 and204 are measured on the outer surface of theouter guide101 and with respect to the inner curve of the bend. The bend radius of the predetermined deflection location will likely change depending on the bend angle as tension is applied to thesteering tendon109. Those skilled in the art can appreciate that the various structural features that are included at thedeflection location102 will influence the initial, unstressed bend radius, as well as the size of the bend radius, as deflection is changed via thesteering tendon109.
• Turning now to an embodiment of theinner guide104, and with reference toFIGS. 1B and 1C, theinner guide104 typically has an outer diameter that is about 4 French to about 10 French. The outer diameter of theinner guide104 is preferably sized to facilitate free movement of theinner guide104 within theouter guide101. Theinner guide104 may be fabricated from an extruded polymer tube. Another configuration is shown inFIG. 1C, where theouter guide101 is fabricated from a multi-layer tubing. The layers of the multi-layer tubing can include a smoothelastomeric casing114, astainless steel braid115, and an innerlubricious lining112 on the inner surface. Thecurve106 at the pre-shapeddistal end116 may be molded or thermoset after extrusion. In catheters where theinner guide104 first finds the destination vessel, and then theouter guide101 is slid over theinner guide104, a relatively stiffinner guide104 is typically desired. In cases where theinner guide104 cannulates the destination vessel and the payload is fed through theinner guide104, a more flexibleinner guide104 with a thinner wall may be desirable.
• Turning toFIG. 3A, an embodiment of the present invention is illustrated in which theinner guide104 is deformable and retractable within theouter guide101. These characteristics advantageously allow thecatheter100 to assume different distal end shapes when theinner guide104 is retracted and extended. The final extended and retracted shapes depend on the dimensions of the pre-shapeddistal end116 of theinner guide104, the dimensions of thepre-determined deflection location102, and the relative flexibility of the inner andouter guides104,101.
• In one configuration, theinner guide104 is deformable and less stiff than theouter guide101. This enables theinner guide104 to be fully retractable within theouter guide101, and allows the catheter's distal end to assume the shape of the outer guidedistal end117 when theinner guide104 is retracted. Such a configuration is advantageous when attempting to cannulate the coronary sinus.
• For example, when theinner guide104 is retracted, thecatheter100 has a broadly curved distal end when navigating from the superior vena cava into the right atrium. After the distal end reaches the right atrium, theinner guide104, which has a much sharper pre-formed bend, is extended. This sharper bend of theinner guide104 offers a more optimal geometry for finding the coronary sinus ostium from the right atrium. Theinner guide104 is typically extendable by at least 2 cm, and more desirably by 5 to 15 centimeters for right atrium use. For other applications, an extension range of at least 0 to 20 centimeters may be desirable.
• FIG. 3B further illustrates the longitudinally displaceableinner guide104. Theinner guide104 is drawn with solid lines and is shown in an initial position relative to theouter guide101. Theinner guide104 is further drawn in phantom lines to illustrate the advantageous change of catheter distal tip shape when extension and retraction of theinner guide104 is combined with a preformed distal tip of theinner guide104 and a deflection location on theouter guide101.
• Turning now toFIG. 4A, an embodiment of theactuator107 provided at the proximal end of thecatheter100 is illustrated. In this embodiment, thesteering tendon109 is terminated outside theouter guide101 and connected to aslideable member406. Applying a proximal force toslideable member406 imparts a tensile force to thesteering tendon109. In this embodiment, theactuator107 further includes a stoppingmember405 that is affixed to at least theouter guide101. The stoppingmember405 acts to prevent distal overtravel of the slidingmember406.
• Further embodiments of the stoppingmember405 can include a locking arrangement to prevent axial rotation of theslideable member406. Yet another embodiment of the stoppingmember405 includes a longitudinal locking arrangement to selectably enable and disable longitudinal translation of theslideable member406. Locking theslideable member406 enables theactuator107 to adjust and then set the shape of thetip deflection102 to a fixed angle. Aspring407 is optionally disposed between the slidingmember406 and theactuator107 to allow automatic return of theslideable member406 to the stoppingmember405 upon release of theslideable member406.
• Those skilled in the art will understand that various mechanisms can be used in place of theslideable member406, such as levers, screws and pull tabs, all of which allow transmittal of axial force to thesteering tendon109. Further, it is appreciated that multiple structural members can be incorporated into theactuator107 to act on a plurality of steeringtendons109 if so desired.
• In the case of the embodiment shown inFIG. 4A, theslideable member406 can include multiple slide members distributed around the perimeter of theouter guide101, eachslideable member406 connected to aseparate steering tendon109. In such an embodiment, eachslideable member406 can independently apply axial forces to its associatedsteering tendon109, allowing for greater control of thedeflection location102.
• Ahemostatic valve301 may be included as part of theactuator107. Thehemostatic valve301 is a standard catheter termination device, such as a Model 23242/5 manufactured by Guidant Corporation, and is well known in the art. In one embodiment, a rotateablehemostatic valve301 connects to both inner and outer guides at the catheter's proximal end, and the proximal end of theinner guide104 protrudes from the proximal end of thehemostatic valve301. In this manner, the proximal end of theinner guide104 is accessible for manipulation. For example, applying a longitudinal force on the proximal end of the inner guide can allow extension and retraction of theinner guide104, as illustrated inFIG. 3B. Thehemostatic valve301 includes aseal409 between the inner andouter guides104,101. The body of thehemostatic valve301 can also serve as a grip from which to rotate theouter guide101.
• Turning now toFIG. 4B, there is illustrated an embodiment of a catheter employing anend electrode401 andband electrodes402 on theinner guide104. Although embodiments of the present invention are directed to guiding applications, it is a commonly desired to obtain ECG readings during implantation of pacing devices or for other coronary access procedures.FIG. 4C shows another embodiment of thecatheter100, where anend electrode403 andband electrodes404 are disposed on thedistal end117 of the outer guide, theinner guide104 further includingelectrodes401 and402 disposed as previously described. The electrodes are mounted flush with the guide outer surfaces and soldered or welded to one or more internally disposed electrical conductors. The composition, number, and dimensions of electrodes may be chosen in a manner well known in the art for various applications. The deployment of electrodes is typically dependent on the desired distal geometry of the catheter and the lumen clearances needed to run conductors through one or both of the inner andouter guides104,101.
• Referring again toFIG. 1C, which shows a cross section near the distal end of the catheter, theinner guide104 is shown centrally disposed within theouter guide101. The inner guide has anopen lumen105. Disposed within thelumen105 areelectrical conductors108 which are connected to theelectrodes401,402,403, and404 and apacing lead118. In one configuration, theelectrical conductors108 are disposed within theouter lumen103. In another configuration, theconductors108 may be embedded within the walls of one or both of theinner guide104 and theouter guide101. Those skilled in the art will appreciate that embodiments of the invention can allow any combination of the described methods of disposing the electrode wires, limited by practical limitations due to the geometry of theguides101 and104,wires108 andpayload118.
• Turning now toFIG. 5, details near the outer guidedistal tip111 are illustrated where asteering tendon109 is attached. In this embodiment, thesteering tendon109 is attached near the distal tip of theouter guide101. Aninterface member502 connects to both thesteering tendon109 andouter guide101 for purposes of transmitting and distributing tensile force to theouter guide101. One configuration of theinterface member502 can include a semicircular stainless steel ring welded or soldered to thesteering tendon109. Theinterface member502 can be attached to theouter guide101 by bonding or embedding the member into the inner surface of theouter guide101.
• InFIG. 5, anocclusion balloon501 is shown attached to a distal section of theouter guide101. During pacing lead implantation, it may be required to occlude blood flow when injecting a radio-opaque dye for purposes of venography. In this embodiment, theouter guide101 would be seated in a location where a venograph is desired, theballoon501 inflated, and a dye injected via theinner guide104 orouter guide101 as appropriate. This advantageously allows venography during an implant procedure without having to remove theouter guide101. The design of theocclusion balloon501 and the inflation means for theballoon501 are well known in the art.
• Turning toFIG. 6A, the delivery of a payload is shown for purposes of illustration. In this case, apacing lead118 represents the payload. In other embodiments of the inventions, the payload can include a radio-opaque dye or an ablation device. In the embodiment ofFIG. 6A, theinner guide104 has been removed by the clinician during the procedure, and thepayload118 can be seated within a coronary vessel via theouter guide101. Alternatively, for a smaller payload or given larger inner guide diameter, the embodiment ofFIG. 6B can be used. In this configuration, theinner guide104 is left in place once it has cannulated the coronary sinus and theinner guide104 provides the guiding pathway for thepayload118.
• It will, of course, be understood that various modifications and additions can be made to the preferred embodiments discussed hereinabove without departing from the scope of the present invention. For example, although the present invention is particularly useful in providing percutaneous access to the coronary sinus ostium via the right atrium, it can be appreciated by one skilled in the art that the present invention is useful in a multitude of guiding catheter applications. Accordingly, the scope of the present invention should not be limited by the particular embodiments described above, but should be defined only by the claims set forth below and equivalents thereof.

Claims (20)

1. A catheter, comprising:

an outer guide comprising an outer guide lumen, a distal end, a proximal end, a predetermined deflection location proximal to the distal end, and a deflection member coupled to the outer guide distal to the predetermined deflection location;

an inner guide comprising an inner guide lumen, a pre-formed distal end, and a proximal end, the inner guide movable within the outer guide lumen and displaceable beyond the distal end of the outer guide; and

an actuator mechanism located at a proximal end of the catheter and coupled to the deflection member, the actuator mechanism configured to change a bend angle at the predetermined deflection location of the outer guide in response to a proximally directed force applied to the deflection member, and the proximal end of the inner guide accessible at the proximal end of the catheter permitting adjustable axial displacement of the pre-formed distal end of the inner guide relative to the distal end of the outer guide.

2. A catheter according toclaim 1, wherein at least 2 centimeters of the inner guide can be axially displaced beyond the distal end of the outer guide.

3. A catheter according toclaim 1, wherein the pre-formed distal end of the inner guide is deformable such that the inner guide is retractable within the distal end of the outer guide.

4. A catheter according toclaim 1, wherein the bend angle is defined relative to a longitudinal axis of the outer guide proximal to the predetermined deflection location.

5. A catheter according toclaim 4, wherein the bend angle is adjustable from a minimum angle of about 0 degrees to a maximum angle of about 150 degrees.

6. A catheter according toclaim 1, wherein a bend radius of the predetermined deflection location is greater than about six times an outer diameter of the outer guide.

7. A catheter according toclaim 1, further including at least one deflection member coupled to the inner guide proximate to the pre-formed distal end.

8. A catheter according toclaim 7, wherein the actuator mechanism produces a tensile force acting on the at least one deflection member coupled to the inner guide to impart a change in the bend angle at the predetermined deflection location of the outer guide.

9. A catheter according toclaim 1, wherein the deflection member coupled to the outer guide comprises at least one steering tendon.

10. A catheter according toclaim 1, further comprising an occlusion balloon affixed at the distal end of the outer guide.

11. A catheter according toclaim 1, further including a seal disposed between the inner guide and the outer guide.

12. A catheter according toclaim 1, further including:

an electrode located at distal end of at least one of the inner guide and outer guide; and

an electrical conductor coupled to the electrode, the electrical conductor extending through the inner guide or outer guide to a proximal section of the catheter.

13. A catheter according toclaim 1, further including:

a plurality of band electrodes disposed at a distal section of at least one of the inner and outer guides; and

at least one electrical conductor connected to the band electrodes, the at least one electrical conductor extending through the inner guide or outer guide to a proximal section of the catheter.

14. A catheter, comprising:

an outer guide comprising an outer guide lumen, a distal end, a proximal end, a predetermined deflection location proximate the distal end, and a deflection member coupled to the outer guide distal to the predetermined deflection location;

an inner guide movable within the outer guide lumen and displaceable beyond the distal end of the outer guide, the inner guide comprising an inner guide lumen dimensioned to receive a cardiac lead, a distal end having a pre-formed deflection proximate the distal end, and a proximal end; and

an actuator mechanism located at a proximal end of the catheter and coupled to the deflection member, the actuator mechanism configured to change a bend angle at the predetermined deflection location of the outer guide in response to a proximally directed force applied to the deflection member, and the proximal end of the inner guide accessible at the proximal end of the catheter permitting adjustable axial displacement of the distal end of the inner guide relative to the distal end of the outer guide.

15. The catheter ofclaim 14, wherein the inner guide lumen is dimensioned to receive a cardiac lead configured for implantation in a coronary sinus of a heart of a patient.

16. The catheter ofclaim 15, wherein the cardiac lead comprises a cardiac pacing lead.

17. A catheter according toclaim 14, wherein the pre-formed distal end of the inner guide is deformable such that the inner guide is retractable within the distal end of the outer guide.

18. A catheter according toclaim 14, wherein the bend angle is defined relative to a longitudinal axis of the outer guide proximal to the predetermined deflection location, wherein the bend angle is adjustable from a minimum angle of about 0 degrees to a maximum angle of about 150 degrees.

19. A catheter according toclaim 14, further including at least one deflection member coupled to the inner guide proximate the pre-formed distal end.

20. A catheter according toclaim 14, wherein a bend radius of the predetermined deflection location is greater than about six times an outer diameter of the outer guide.

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