CROSS-REFERENCEThis application is a continuation of U.S. patent application Ser. No. 10/946,332, filed Sep. 20, 2004, now U.S. Pat. No. 7,837,729, which is a continuation-in-part of U.S. patent application Ser. No. 10/313,914, filed Dec. 5, 2002, now U.S. Pat. No. 7,316,708, and of U.S. patent application Ser. No. 10/331,143, filed Dec. 26, 2002, now U.S. Pat. No. 6,793,673; which applications are incorporated herein by reference in their entirety and to which applications we claim priority under 35 USC §120.
BACKGROUND OF THE INVENTIONThe invention relates generally to percutaneous delivery systems for tissue shaping devices intended to be delivered through a lumen to a site within a vessel of the patient to modify target tissue adjacent to the vessel. In particular, the invention relates to delivery systems for percutaneous mitral valve annuloplasty devices and methods for using the same.
Tissue shaping devices for treating mitral valve regurgitation have been described. See, e.g., U.S. patent application Ser. No. 10/142,637 (now U.S. Pat. No. 6,824,562), “Body Lumen Device Anchor, Device and Assembly;” U.S. patent application Ser. No. 10/331,143 (now U.S. Pat. No. 6,793,673), “System and Method to Effect the Mitral Valve Annulus of a Heart;” U.S. patent application Ser. No. 10/429,172, “Device and Method for Modifying the Shape of a Body Organ;” and U.S. patent application Ser. No. 10/742,516, “Tissue Shaping Device With Conformable Anchors.” These devices are intended to be delivered percutaneously to a site within a patient's coronary sinus and deployed to reshape the mitral valve annulus adjacent to the coronary sinus.
During deployment of such tissue shaping devices one or more anchors may need to be expanded and locked using actuation forces delivered from outside the patient. Thus, the percutaneous delivery and deployment of tissue shaping devices may require the physician to perform remote operations on the device and on the patient through the device. What is needed, therefore, is a delivery system that permits the physician to perform these tasks.
SUMMARY OF THE INVENTIONThe present invention provides a tissue shaping delivery system and method. One aspect of the invention is a tissue shaping system including a tissue shaping device with an expandable anchor and a lock; a delivery catheter; a delivery mechanism (including, e.g., a pusher) adapted to deliver the tissue shaping device from outside a patient to a target site within a lumen within the patient via the delivery catheter; and an actuator adapted to deliver an actuation force to the lock to lock the anchor in an expanded configuration. In some embodiments, the invention includes a cartridge adapted to contain the tissue shaping device, the delivery mechanism being further adapted to deliver the tissue shaping device from the cartridge to the delivery catheter. The tissue shaping system may also include a dye port adapted to admit an imaging contrast agent to the lumen, such as during delivery and deployment of the tissue shaping device. The dye port may be part of a connector extending from a proximal end of the delivery catheter, with the connector also, including a device port, the delivery mechanism being further adapted to delivery the tissue shaping device from outside the patient to the delivery catheter through the device port.
In some embodiments the tissue shaping system includes a handle associated with the delivery mechanism. The handle may be adapted to support the actuator. In embodiments in which the system includes a cartridge adapted to contain the tissue shaping device, the cartridge may be further adapted to engage the handle during delivery and/or deployment of the tissue shaping device.
In some embodiments of the tissue shaping system, the actuator is further adapted to operate the delivery mechanism to move the tissue shaping device with respect to the delivery catheter to, e.g., expose or recapture the anchor. In some embodiments, the actuator is a rotating nut.
In some embodiments of this aspect of the invention the actuator is adapted to move the delivery catheter distally to lock the anchor. In other embodiments the tissue shaping system may also include a locking sleeve, the actuator being further adapted to move the locking sleeve distally to lock the anchor.
In some embodiments the tissue shaping system includes an attachment mechanism adapted to attach the tissue shaping device to the delivery mechanism, such as a tether attached to the tissue shaping device. The attachment mechanism may be further adapted to release the tissue shaping device from the delivery mechanism, such as through the use of a hitch wire and a tether attached to the tissue shaping device. The attachment mechanism may also include a hitch wire actuator adapted to move the hitch wire to release the tether from the device and/or a device release interlock adapted to prevent release of the device prior to actuating the anchor lock actuator.
In some embodiments of the tissue shaping system, the tissue shaping device further includes a second anchor, the actuator being further adapted to deliver an actuation force to a second anchor lock to lock the second anchor in an expanded configuration. The system may alternatively have a second actuator, the second actuator being further adapted to deliver an actuation force to the second anchor lock to lock the second anchor in an expanded configuration. A handle may support the first and second actuators.
Another aspect of the invention provides a system adapted to percutaneously deliver and deploy a tissue shaping device at a target site within a lumen of a patient, including: a handle; a delivery mechanism (possibly including a pusher) supported by the handle and adapted to deliver the tissue shaping device from outside the patient to the treatment site via a delivery catheter; and an actuator supported by the handle and adapted to deliver an actuation force to lock an anchor of the tissue shaping device in an expanded configuration. In some embodiments the handle has a cartridge interface adapted to mate with a cartridge containing a tissue shaping device, and the delivery system may be further adapted to deliver the tissue shaping device from a delivery catheter to the target site when a tissue shaping device cartridge engages the cartridge interface. In some embodiments, the actuator may include the cartridge interface. In some embodiments the actuator may include a rotating member with threads adapted to mate with threads on a cartridge.
In some embodiments the system includes a locking sleeve, the actuator being further adapted to move the locking sleeve distally to lock the anchor. The handle may include a channel, with the actuator being disposed in the channel, and the actuator may include an actuator lock adapted to prevent movement of the actuator within the channel.
In some embodiments the system includes a device attachment mechanism supported by the handle and adapted to attach the tissue shaping device to the handle. The attachment mechanism may include a tether attached to the handle and/or a hitch wire attached to the handle. In embodiments with a hitch wire the attachment mechanism further may a hitch wire actuator adapted to move the hitch wire to release the device and possibly a device release interlock adapted to prevent operation of the hitch wire actuator prior to actuating the anchor lock actuator.
INCORPORATION BY REFERENCEAll publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGSThe novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
FIG. 1 is a cross-sectional view of a human heart showing a tissue shaping device in the lumen of the coronary sinus.
FIG. 2 is a schematic view of a tissue shaping device delivery system according to this invention.
FIG. 3 is a cross-sectional view showing a step in the delivery and deployment of a tissue shaping device according to this invention.
FIG. 4 is a cross-sectional view showing another step in the delivery and deployment of a tissue shaping device according to this invention.
FIG. 5 is a cross-sectional view showing another step in the delivery and deployment of a tissue shaping device according to this invention.
FIG. 6 is a cross-sectional view showing another step in the delivery and deployment of a tissue shaping device according to this invention.
FIG. 7 is a cross-sectional view showing a step in the recapture of a tissue shaping device according to this invention.
FIG. 8 is a cross-sectional view showing a step in the recapture of a tissue shaping device according to this invention.
FIG. 9 shows an attachment mechanism for a tissue shaping device delivery system.
FIG. 10 shows another attachment mechanism for a tissue shaping device delivery system.
FIG. 11 shows yet another attachment mechanism for a tissue shaping device delivery system.
FIG. 12 shows still another attachment mechanism for a tissue shaping device delivery system.
FIG. 13 is a detail of the attachment mechanism ofFIG. 12 in a disengaged configuration.
FIG. 14 is a perspective view of a tissue shaping device delivery system according to this invention.
FIG. 15 is another perspective view of the tissue shaping device delivery system ofFIG. 14 showing a tissue shaping device without a cartridge.
FIG. 16 is an exploded view of the tissue shaping device and delivery system ofFIG. 15.
FIG. 17 is a partial cross-sectional view of certain portions of the tissue shaping device delivery system ofFIG. 15.
FIG. 18 is a detailed cross-sectional view of a portion of the tissue shaping device shown inFIG. 17.
FIG. 19 is a perspective view of a cartridge for the tissue shaping device delivery system ofFIG. 14.
FIG. 20 is a cross-sectional view of the cartridge ofFIG. 19.
FIG. 21 is a cross-sectional view of a delivery catheter and connector for use with the tissue shaping device delivery system ofFIGS. 14-20.
DETAILED DESCRIPTION OF THE INVENTIONWhile the invention relates to methods and devices for delivering tissue shaping devices generally, the invention will be described with respect to tissue shaping devices delivered to the coronary sinus of the heart to reshape the mitral valve annulus to treat mitral valve regurgitation. As used herein, “coronary sinus” includes the great cardiac vein as well as the coronary sinus of the heart.
FIG. 1 shows a cross-section of ahuman heart10 with the atria removed to show themitral valve12, themitral valve annulus14 and the coronary sinus16. Atissue shaping device20 in the form of a percutaneous mitral valve annuloplasty device is disposed within the coronary sinus to reshape themitral valve annulus14 to provide for improved coaptation of the mitral valve leaflets. As shown,tissue shaping device20 has an expandabledistal anchor22, adistal anchor lock24, an expandableproximal anchor26, aproximal anchor lock28, and aconnector30 extending between the distal and proximal anchors.Proximal anchor lock28 has serves as a delivery system attachment mechanism, as explained below.
FIG. 2 is a schematic drawing showing the general elements of adelivery system40 adapted to delivering and deploying a tissue shaping device to a target site within the lumen of a vessel in or around a patient'sheart42. Adelivery catheter44 has been inserted through anopening46 formed in the patient's jugular vein or other blood vessel and advanced into the heart.Delivery system40 interacts withdelivery catheter44 to deliver and deploy the tissue shaping device at the target site within the patient.
FIGS. 3-6 show steps from the delivery and deployment of a tissue shaping device having at least one anchor similar to the anchors ofdevice20 ofFIG. 1. InFIG. 3, atissue shaping device50 has been delivered to a target site within the lumen of avessel54 via adelivery catheter56.FIG. 3 shows anexpandable anchor52 oftissue shaping device50 beginning to emerge fromcatheter56. In this embodiment, this action is due to proximal movement ofcatheter56 whiledevice50 is held stationary. In alternative embodiments, the device could be delivered from the distal end of the catheter by pushing the device distally while holding the catheter stationary or a combination of distal movement of the device and proximal movement of the catheter.Anchor52 is shown in a collapsed, unexpanded configuration.
Adelivery system70 provides the mechanisms to deliver and deploydevice50 from outside the patient.Actuator72 anddelivery mechanism74 associated withcatheter56 anddevice50, respectively, provide for the relative movement betweendevice50 andcatheter56. For example,delivery mechanism74 may be a pusher used to advancedevice50 downcatheter56 to the target site shown inFIG. 3, andactuator72 can be used to pullcatheter56 proximally whiledelivery mechanism74 holdsdevice50 stationary withinvessel54.Actuator72 anddelivery mechanism74 may be supported by a handle orother housing76.
InFIG. 4,catheter56 has been pulled further proximally byactuator72 so thatanchor52 is completely outside ofcatheter56 and has started to self-expand. In this embodiment,anchor52 is formed from a shape memory material (such as Nitinol) and has been treated so as to expand upon emergence from the catheter.
FIGS. 5 and 6 show how the delivery system may be used to further expand and lockanchor52. Formed in theproximal side58 ofanchor52 is aloop60 encircling aproximally extending connector62.Connector62 may connect with other elements at the proximal side ofdevice50, such as a second anchor, depending on device design. As shown inFIG. 5, whiledelivery mechanism74 holdsdevice50 stationary,actuator72 has moveddelivery catheter56 distally to engage theproximal side58 ofanchor52 and to move it distally to further expandanchor52.
As shown inFIG. 6, further distal movement ofdelivery catheter56 with respect todevice50 has pushedloop60 distally over alock bump64.Lock bump64 cams inward in response to the distal force ofloop60, then returns to its prior shape to holdloop60 distal to lockbump64. Delivery catheter may then be moved proximally to perform other functions or to be removed from the patient.
After deployment of a tissue shaping device, it may become necessary to reposition the device or to remove the device from the patient.FIGS. 7 and 8 demonstrate the recapture oftissue shaping device50 back intodelivery catheter56 after delivery and deployment.
InFIG. 7,delivery mechanism74 holdsdevice50 stationary whiledelivery catheter56 is advanced distally againstanchor52 byactuator72. The actuation force againstanchor52 collapses the anchor, allowing delivery catheter to recapture the device as shown inFIG. 8. The catheter and device can then be removed from the patient or moved to another target site.
FIG. 9 shows an attachment mechanism between atissue shaping device80 and a delivery mechanism, such aspusher82, within adelivery catheter84. Pusher extends outside of the patient and is attached to a handle orother housing86, such as through an actuator.Pusher82 may be operated by an actuator or by the handle itself to advancedevice80 distally throughcatheter84 or to holddevice80 stationary against a proximal force exerted ondevice80, such as whendelivery catheter84 is withdrawn proximally by an actuator88.
Device80 has anattachment eyelet90. Atether92 extending downpusher82 has a loop94 formed at its distal end. The proximal ends oftether92 are preferably attached to handle86. Loop94 extends througheyelet90, and ahitch wire96 passes through loop94 and into the proximal end ofdevice80 as shown, thereby preventing loop94 from being withdrawn fromeyelet90.Tether92 can be used to pulldevice80 proximally or to holddevice80 stationary against a distal force exerted ondevice80, such as during recapture.Tether92 may also be used to holddevice80 tightly againstpusher82 during delivery and deployment of the device.
To releasedevice80 from the delivery mechanism,hitch wire96 may be disengaged fromdevice80. In this embodiment,hitch wire96 is disengaged by moving the hitch wire proximally through the action of ahitch wire actuator98 while holdingdevice80 stationary withpusher92. Whenhitch wire96 is disengaged fromdevice80 and moved proximal to the loop oftether92, proximal movement oftether92 will pull the tether's loop out ofeyelet90.
FIG. 10 shows another attachment mechanism for a tissue shaping device and its delivery mechanism. As in the embodiment ofFIG. 9, aneyelet102 extends proximally fromtissue shaping device100 withindelivery catheter104. The distal end ofpusher106 has aneyelet108 at its distal end that overlaps withdevice eyelet102 to form anoverlap opening110. Ahitch wire112 extends throughpusher106 and overlap opening110 into the proximal end oftissue shaping device100.
As in the previous embodiment,catheter104,pusher106 andhitch wire112 extend out of the patient to a handle orother housing114.Pusher106 may be operated by an actuator or byhandle114 to advancedevice100 distally throughcatheter104 or to holddevice100 stationary against a proximal force exerted ondevice100, such as whendelivery catheter104 is withdrawn proximally by anactuator116 supported byhandle114. Also, because the attachment mechanism of this embodiment holdspusher106 againstdevice100,pusher106 can be used to pulldevice100 proximally or to holddevice100 stationary against a distal force exerted ondevice100, such as during recapture.
To releasedevice100 from the delivery mechanism,hitch wire112 may be disengaged fromdevice100. As in the embodiment ofFIG. 9,hitch wire112 is disengaged by moving the hitch wire proximally through the action of ahitch wire actuator118 while holdingdevice100 stationary withpusher106. Whenhitch wire112 is disengaged fromdevice100 and moved proximal to theoverlap opening110,device100 is disengaged from the delivery mechanism.
FIG. 11 shows an attachment mechanism that can be used to engage a tissue shaping device after initial deployment for possible recapture of the device. As in other embodiments,device120 has aproximal eyelet122.Retractor124 has acable126 extending through it.Cable126 has aloop128 at its distal end andfree ends130 extending out of the patient, possibly to a handle or housing (not shown). To engagedevice120,retractor124 and loopedcable126 are advanced todevice120 withloop128 arranged to be large enough to surroundeyelet122. Whenloop128 passes over and aroundeyelet122, one or both of the free ends ofcable126 are pulled proximally to pullloop128 tightly abouteyelet122, as shown.Retractor124 may then be used to pulldevice120 proximally, such as for recapture into a catheter. Alternatively, retractor may be used as a pusher to apply a distally directed force ondevice120, if needed.
FIGS. 12 and 13 show yet another attachment mechanism between a tissue shaping device and a delivery mechanism.Tissue shaping device140 has a lockingstructure142 at its proximal end designed to mate with acorresponding locking structure144 at the distal end of apusher146 withincatheter148. Acover150 is disposed over the interlocked locking structures to maintain the connection betweendevice140 andpusher146. Atether152 is connected to cover150.
Catheter148,pusher146 andtether152 extend out of the patient to a handle or other housing154.Pusher146 may be operated by an actuator or by handle154 to advancedevice140 distally throughcatheter148 or to holddevice140 stationary against a proximal force exerted ondevice140, such as whendelivery catheter148 is withdrawn proximally by anactuator156 supported by handle154. Also, because the attachment mechanism of this embodiment holdspusher146 againstdevice140,pusher146 can be used to pulldevice140 proximally or to holddevice140 stationary against a distal force exerted ondevice140, such as during recapture.
To releasedevice140 from the delivery mechanism,tether152 may be pulled proximally to pullcover150 off of the lockingstructures142 and144, such as by use of anactuator158, while holdingdevice100 stationary withpusher146. Lockingstructures142 and144 are preferably formed from a shape memory material. Whencover150 is removed from the locking structures, the locking structures assume an unstressed configuration such as that shown inFIG. 13, thereby disengagingdevice140 frompusher146.
FIGS. 14-21 show a tissue shaping device delivery and deployment system according to one embodiment of this invention. The system includes ahandle200 supporting delivery, deployment and attachment mechanisms for atissue shaping device202 having distal and proximalexpandable anchors204 and206, respectively. InFIG. 14, the device is disposed in a compressed configuration within acartridge208. In this embodiment, the device will go directly fromcartridge208 into a delivery catheter for delivery and deployment in a patient.
As shown inFIG. 15, apusher210 abuts the proximal end oftissue shaping device202.Pusher210 should be flexible and incompressible, and its properties may vary from section to section along its length. In one embodiment,pusher210 is formed at its distal end from a coiled spring212 (e.g., to facilitate bending) and thereafter from astainless steel hypotube214.Device202 is attached topusher210 via atether216 andhitch wire218 in an arrangement such as that described above with respect toFIG. 9. The tether has to be strong enough to apply an appropriate proximally directed force during delivery, deployment and recapture; the hitch wire has to be stiff enough not to kink or pull through the eyelet when the tether is pulled proximally. For example, for use in a tissue shaping system intended to treat mitral valve regurgitation via the coronary sinus, the tether preferably can pull up to 18 pounds. In one embodiment,tether216 is formed from 0.007 inch stainless steel with a full hard temper, and hitch wire is formed from 0.011 inch304 stainless steel. Tether216 andhitch wire218 extend through the pusher's lumen.Pusher210,tether216 andhitch wire218 are attached to and supported byhandle200, as discussed below with respect toFIGS. 17 and 18.
Surrounding pusher210 is a lockingsleeve220 whose inner diameter is close to the outer diameter ofpusher210 in order to minimize backflow of blood or other fluids. The proximal end of lockingsleeve220 is supported by a slider (not shown) resting in a circular track formed by the handle housing.Actuator knobs222 are threaded into holes formed in the sides of the slider, and the slider and actuator knobs are attached to the lockingsleeve220 by adhesive. One of the actuator knobs may be provided with an actuation interlock, such as a screw downportion223 that screws against the handle housing to prevent movement of the actuator knobs and locking sleeve. As shown inFIG. 16, actuator knobs222 fit intracks224 formed inhandle200.
When assembling the delivery system,pusher210 is placed within lockingsleeve220. Handlehousing226 has two parts,228 and230, which are placed and screwed together around the locking sleeve and pusher. As shown inFIG. 18, assembly of the two halves ofhandle housing226 attaches the proximal end ofpusher210 to handle200 with a press fit connection (which may be supplemented with adhesive) in apusher connection area232 ofhandle housing226. Locking sleeve actuator knobs222 are in thetracks224, as discussed above.
Hitch wire218 andtether216 are then threaded into the central lumen ofpusher210, anddevice202 is attached by placing the looped end oftether216 through an eyelet (not shown) on the proximal end ofdevice202.Hitch wire218 passes through the looped end oftether216 into the device's proximalanchor crimp tube207. (Placement of the distal end of the hitch wire inside the crimp tube helps prevent injury to the patient's heart or blood vessels by the hitch wire.)
Tether216 andhitch wire218 extend proximally from the proximal end ofpusher210 through the proximal end ofpusher connection area232 and through holes formed in adisc236 disposed proximal topusher connection area232 andjack nut234. Acrimp tube238 or other connector attaches to the proximal end oftether216 to prevent it from passing distally throughdisc236; excess portions oftether216 may be cut off. Ajack nut234 threaded around the outside ofpusher connection area232 may then be rotated aboutpusher connection area232 to movejack nut234,disc236 and crimptube238 proximally with respect to the handle housing, thereby tighteningtether216 and pullingdevice202 tight againstpusher210.
Arelease knob240 is threaded ontohandle housing226 aroundpusher connection area232 withtrack portions242 lining up withhandle tracks224, as shown.Hitch wire218 extends proximally throughrelease knob240 and asecond disc244, and the proximal end ofhitch wire218 is crimped with one ormore crimp tubes246 to prevent distal movement ofhitch wire218 with respect to the handle. Acap248 covers the distal end ofhitch wire218 to prevent injury to the user from the sharp wire end.
Prior to delivery and deployment, the eyelet of theproximal anchor206 is pulled proximally over thepusher coil212, and the eyelet of the distal anchor is pulled proximally over the connector between the two anchors.Device202 is then compressed and loaded intocartridge208 with thedistal anchor204 at the distal end of the cartridge and with the pusher, tether and hitch wire extending from the proximal end ofcartridge208 intohandle200. A loading tool, such as a two-piece funnel, may be used to assist in the compression and loading of the device into the cartridge. In a preferred embodiment, acontrol nut250 is threaded onto the threaded exterior ofcartridge208, as shown inFIG. 14.
Cartridge208 is shown in more detail inFIGS. 19 and 20.Cartridge208 has a central lumen252 with a lubricious polymeric liner. The diameter of central lumen252 may be substantially the same as the diameter of a delivery catheter to be used to deliverdevice202. Alternatively, the diameter of central lumen252 may be larger than the intended delivery catheter diameter to minimize stress on the tissue shaping device during sterilization, temperature changes during shipping, etc.Cartridge208 has amale luer connector254 at its distal end for mating with a corresponding female luer connector on the delivery catheter, as described below. The outside of the cartridge preferably has at least one flat side in order to prevent rotation of the cartridge with respect to the handle during deployment, as described below. In the embodiment shown inFIGS. 19 and 20,cartridge208 has a hexagonal cross-section presenting six possible orientations for mating with a flat side formed on the inside of the handle during delivery and deployment of the tissue shaping device. An O-ring seal255 at the proximal end ofcartridge208 seals around lockingsleeve220 to prevent backflow of blood or other fluids while still permitting relative movement between lockingsleeve220 andcartridge208.
FIG. 21 shows a delivery catheter260 andconnector262 for use with the cartridge and handle of this invention. The length and diameter of catheter260 depends on the application. For example, to deliver a tissue shaping device to the coronary sinus through the jugular vein to treat mitral valve regurgitation, catheter260 may be a nine french diameter catheter at least 65 cm. long. Catheter260 may also have a radiopaque market on its distal end for visualization via fluoroscopy. When it needs to negotiate bends and turns to reach the target treatment site, catheter260 may be more flexible at its distal tip than along its proximal end. Catheter260 may also be braided to increase its compression strength, which aids in locking anchors, recapturing devices, etc., as described below.
Y-shapedconnector262 is attached to the proximal end of catheter260 by adhesive and ashrink tube264.Connector262 has amain channel266 with afemale luer connection268 adapted to mate with the luer connection ofcartridge208. Asecond channel270 meets themain channel266 proximal to the proximal end of delivery catheter260.Second channel270 also has a luer connection to permit it to be connected to a source of imaging contrast agent, such as dye.Second channel270 enables a dye source to be connected and for dye to be injected even during use of the main channel to deliver and deploy the tissue shaping device. (The space between the inner diameter of the delivery catheter and the outer diameter of the locking sleeve permits contrast dye to flow distally to the target treatment site.) Acap272 may be used to close offsecond channel270 when not in use. The diameters of both channels transition down from the standard luer fitting size to the diameter of the delivery catheter.
A first step for using the tissue shaping system of this invention to treat mitral valve regurgitation is to access the coronary sinus of the patient's heart. One way of reaching the coronary sinus is to insert a sheath into the patient's jugular vein. A guide catheter with a precurved tip may then be inserted into the sheath and advanced to coronary sinus ostium within the right atrium of the heart. A guidewire may then be advanced through the guide catheter and into the coronary sinus, and the guide catheter may be removed from the patient, leaving the guidewire behind. The delivery catheter260 may then be advanced along the guidewire, and the guidewire may be removed.
The anatomy of the heart varies from patient to patient. For example, the diameter and length of the coronary sinus are patient-dependent as well as the location of coronaries arteries that may pass between the coronary sinus and the heart. One optional method step, therefore, is to introduce dye or another imaging contrast agent into the coronary sinus through the delivery catheter (such as through the Y-shaped connector262) to perform a venogram while performing an angiogram on the coronary arteries in a known manner. These images will identify the relative positions of the coronary sinus and coronary arteries and will give a relative indication of the length and diameter of the coronary sinus at the target treatment site.
In addition, in order to calibrate the venogram with the actual size of the imaged vessels, a marker catheter may be inserted into the coronary sinus through the delivery catheter during the venogram. The marker catheter has radiopaque markings a fixed distance apart. By measuring on the venogram the distance between markings on the marker catheter, a correction factor may be devised to correct the measured diameter and length of the coronary sinus. Alternatively, radiopaque markings may be added to the delivery catheter itself, thereby eliminating the need to insert a marker catheter to obtain the correction factor measurements. Dye may also be injected during delivery and deployment of the tissue shaping device for imaging purposes.
After removal of the marker catheter, the delivery system may be attached to the delivery catheter. Prior to the start of the procedure, lockingsleeve220 is in its proximal-most position so that locking sleeve actuator knobs222 are inslots242 ofrelease knob240, and screw downportion223 is screwed againsthousing226 to hold lockingsleeve220 in place.Pusher210 and lockingsleeve220 extend from the distal end ofhandle200 to thedevice202 withincartridge208. The lengths ofpusher210 and lockingsleeve220 correspond to the length of delivery catheter260, as discussed below. Lengths ofpusher210 and lockingsleeve220 may be exposed betweenhandle200 andcartridge208.
To begin deliveringtissue shaping device202 to the patient's coronary sinus, cartridge208 (containing tissue shaping device202) and delivery catheter260 are then connected atluer connection268 of the main channel of Y-connector262. The distal tip of the delivery catheter is in place in the coronary sinus at the distal end of the target treatment site. To begin delivery of the device fromcartridge208 into delivery catheter260, handle200 is advanced distally towardcartridge208 and delivery catheter260. As the handle advances toward the cartridge and toward the patient,pusher210 movesdevice202 distally out ofcartridge208 into Y-connector262 and then into delivery catheter260. The structure of the point where the Y-connector'ssecond channel270 meets themain channel266—specifically, reduceddiameter portion274 andtab276—helps prevent the tissue shaping device from expanding and getting caught at the junction of the two channels.
In certain embodiments of the invention, the advancinghandle200reaches cartridge208 when or beforedevice202 reaches the distal end of delivery catheter260. For example, in the embodiment shown inFIGS. 14-21, the relative lengths ofdevice202,pusher210, handle200 and delivery catheter260 are such that the distal end ofhandle200 reaches the proximal end ofcartridge208 beforedevice202 reaches the distal end of delivery catheter260. After this point, further advancement ofhandle200 places handlehousing226 aroundcartridge208 so thatcartridge208 moves inside the handle. A flat interior surface (not shown) formed inhandle200 mates with one of the flat sides ofcartridge208 to prevent relative rotation between the cartridge and the handle ascontrol nut250 rotates.
In one embodiment, rotatingcontrol nut250 is threaded ontocartridge208 prior to use of the system to treat a patient, as shown inFIG. 14. The location ofcontrol nut250 oncartridge208 depends on the length of thedevice202 withincartridge208 as well as the relative lengths of the pusher and delivery catheter. In this embodiment, these elements are sized and configured so thatcontrol nut250 engages with, and snaps to, the distal end ofhandle200 at the point during device delivery whendevice202 has reached the distal end of delivery catheter260. This action engagescartridge208 withhandle200 for controlled delivery and deployment oftissue shaping device202. Alternatively,control nut250 can be disposed on the distal end ofhandle200 from the start. In this case,cartridge208 engages handle200 throughcontrol nut250 as soon the proximal end ofcartridge208 reaches handle200, which may be beforedevice202 has reached the distal end of delivery catheter260.
Aftercartridge208 engages handle200 throughcontrol nut250, all further relative movement betweencartridge208 and handle200 is controlled by rotatingcontrol nut208. Whentissue shaping device202 is at the distal end of catheter260 at the distal end of the target treatment site (as determined fluoroscopically, e.g.) the physician ceases movinghandle200 toward the patient. Instead, handle200 (and therefore device202) is held stationary whilecartridge208 and delivery catheter260 are pulled proximally by rotatingcontrol nut250. This action exposes the device'sdistal anchor204, which begins to self-expand.Control nut250 is then rotated the other direction to advance delivery catheter260 distally to apply a force to the proximal side ofanchor204 to further expand and lock the anchor, i.e., by advancing the anchor's lock loop over its lock bump, as described above. Thus,control nut250 acts as an actuator for expanding and locking the device's distal anchor.
After locking the distal anchor, a proximal cinching force is applied to the device throughtether216 to reshape the mitral valve annulus by movinghandle200 proximally away from the patient, preferably while observing the status of the patient's mitral valve regurgitation and vital signs, such as described in U.S. patent application Ser. No. 10/366,585, “Method of Implanting a Mitral Valve Therapy Device.” Contrast dye may be injected viaconnector262 to visualize the anchor while cinching. When an appropriate amount of mitral valve regurgitation has been achieved,control nut250 is rotated while holdinghandle200 in place to pull delivery catheter260 proximally with respect totissue shaping device202, thereby exposingproximal anchor206, which begins to self-expand.
In one embodiment of the invention, lockingsleeve220 is used in place of the larger diameter delivery catheter to further expand and lockproximal anchor206 in order to avoid inadvertent recapture of the proximal anchor by the delivery catheter. Screw downportion223 ofknobs222 is loosened to permitknobs222 to slide forward intracks224, thereby advancing lockingsleeve220 distally towardanchor206. Lockingsleeve220 applies a distally directed force on the proximal side ofanchor206 to further expand and lock the anchor, i.e., by advancing the anchor's lock loop over its lock bump, as described above. Thus, knobs222 act as an actuator for expanding and locking the device's proximal anchor. Expansion and locking of the proximal anchor maintains the cinching action and, therefore, the reduction in mitral valve regurgitation caused by the device's reshaping of the mitral valve annulus.
Alternatively, the delivery catheter can be used to expand and lock the proximal anchor in the same manner as the distal anchor.
The delivery system of this embodiment enables the tissue shaping device to be fully deployed before it is detached from the delivery system. If the tissue shaping device's placement is satisfactory, the device is unhitched from the delivery system. To unhitch,release knob240 is rotated to move release knob and the attachedhitch wire218 proximally with respect todevice202. This action pulls the distal end ofhitch wire218 out of the device'sproximal anchor crimp207 and releases the looped end oftether216, thereby disengagingdevice202 from the delivery system. The delivery catheter, tether and hitch wire may then be removed from the patient.
Theslots242 inrelease knob240 prevent rotation ofrelease knob240 when lockingsleeve220 is in its proximal-most position. This device release interlock feature helps ensure that the locking sleeve has been used to lock the proximal anchor before the tissue shaping device is disengaged from the delivery system.
In certain instances, after initial deployment but before disengaging the hitch wire and tether the tissue shaping device may need to be recaptured and either removed from the patient or deployed at a different site. In that case, lockingsleeve220 is advanced distally to the proximal side ofproximal anchor206 by movingknobs222 forward intracks224. While holdinghandle200 stationary to holddevice202 against distal movement through the action oftether216,control nut250 is rotated to advance delivery catheter260 distally over lockingsleeve220 to and overproximal anchor206, deforminganchor206 so that it fits back inside catheter260. In this manner,control nut250 is used as a recapture actuator; use of the control nut to apply the recapture force helps prevent a sudden inadvertent distal advancement of the catheter when the anchor collapses and enters the catheter. Once the proximal anchor has been recaptured into the delivery catheter, the catheter is then advanced further distally to recapturedistal anchor204 in the same way.Device202 can then be moved or removed from the patient.
While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.