Delivery systems for cardiac valve devices

Delivery systems for placing an implantable cardiac device at a native comprising a delivery catheter and an attachment assembly. The delivery catheter can include a proximal portion and a distal portion, and the attachment assembly can be at the distal portion of the delivery catheter. The attachment assembly can include arm pairs in which individual arm pairs include a first arm with connector and a second arm with a retainer. Each first arm extends along a corresponding second arm, and the first arm and/or the second arm in each arm pair moves relative to the other from a locked position to a released position. In the locked position, the retainer interfaces with the connector to maintain engagement between the implantable device and the connector. In the released position, the retainer is positioned relative to the connector such that the implantable device can disengage the connector.

TECHNICAL FIELD

Delivery systems for implanting cardiac valve devices via a minimally invasive endovascular approach or via a mini-thoracotomy.

BACKGROUND

Proper functioning of the mitral valve can be affected by mitral valve regurgitation, mitral valve prolapse, or mitral valve stenosis. Mitral valve regurgitation can occur when the leaflets of the mitral valve fail to coapt into apposition at peak contraction pressures such that blood leaks from the left ventricle into the left atrium. Several structural factors may affect the proper closure of the mitral valve leaflets. For example, an enlarged mitral annulus caused by dilation of heart muscle may prevent proper coaptation of the leaflets during systole. Other conditions involve a stretch or tear in the chordae tendineae, the tendons connecting the papillary muscles to the inferior side of the mitral valve leaflets, which may also affect proper closure of the mitral annulus. A ruptured chordae tendineae, for example, may cause a valve leaflet to prolapse into the left atrium due to inadequate tension on the leaflet. Abnormal backflow can also occur when the papillary muscles are compromised (e.g., due to ischemia) such that the affected papillary muscles do not contract sufficiently to effect proper closure during systole.

Mitral valve prolapse can occur when the mitral leaflets abnormally bulge up in to the left atrium, which can also lead to mitral valve regurgitation. Normal functioning of the mitral valve may also be affected by mitral valve stenosis, or a narrowing of the mitral valve orifice, which impedes of filling of the left ventricle during diastole.

Mitral valve regurgitation is often treated using diuretics and/or vasodilators to reduce the amount of blood flowing back into the left atrium. Other treatment methods, such as surgical approaches (open and intravascular), have also been used to either repair or replace the native mitral valve. For example, cinching or resecting portions of the dilated annulus are typical repair approaches.

Cinching of the annulus has been accomplished by implanting annular or peri-annular rings which are generally secured to the annulus or surrounding tissue. Other repair procedures have also involved suturing or clipping of the valve leaflets into partial apposition with one another.

Alternatively, more invasive procedures replace the entire valve with mechanical valves or biological tissue. These invasive procedures are conventionally done through large open thoracotomies and are thus very painful, have significant morbidity, and require long recovery periods.

However, with many repair and replacement procedures, the durability of the devices or improper sizing of annuloplasty rings or replacement valves may cause complications. Moreover, many of the repair procedures depend upon the skill of the cardiac surgeon since poorly or inaccurately placed sutures may affect the success of procedures.

Compared to other cardiac valves, the mitral valve presents unique challenges because portions of the mitral valve annulus have limited radial support from surrounding tissue and the mitral valve has an irregular, unpredictable shape. For example, the anterior wall of the mitral valve is bound by only a thin wall separating the mitral valve annulus from the inferior portion of the aortic outflow tract. As a result, significant radial forces on the mitral valve annulus are not acceptable as they could lead to collapse of the inferior portion of the aortic tract with potentially fatal consequences. Another challenge of the mitral valve anatomy is that the maze of chordae tendineae in the left ventricle makes navigating and positioning a deployment catheter much more difficult compared to other heart valves. Given the difficulties associated with current procedures, there remains the need for simple, effective, and less invasive devices and methods for treating dysfunctional heart valves. Additionally, since it is also difficult to deliver devices to the mitral valve, there also remains the need for effective and less invasive delivery systems to deliver the implantable cardiac devices to the mitral valve.

DETAILED DESCRIPTION

Disclosed herein are examples of delivery systems for implanting a medical device, such as a valve repair device or a prosthetic heart valve, in a native heart. In some embodiments, delivery systems for placing an implantable cardiac device at a native heart valve comprise a delivery catheter and an attachment assembly. The delivery catheter can include a proximal portion and a distal portion, and the attachment assembly can be at the distal portion of the delivery catheter. The attachment assembly can include arm pairs in which individual arm pairs include a first arm with a connector and a second arm with a retainer. Each first arm extends along a corresponding second arm, and the first arm and/or the second arm in each arm pair moves relative to the other from a locked position to a released position. In the locked position, the retainer interfaces with the connector to maintain engagement between the implantable device and the connector. In the released position, the retainer is positioned relative to the connector such that the implantable device can disengage the connector.

FIG.1shows a mitral valve which may be accessed by a delivery system according to the present technology. The anterior leaflet has a semi-circular shape and attaches to two-fifths of the annular circumference. The motion of the anterior leaflet defines an important boundary between the inflow (diastole) and outflow (systole) tracts of the left ventricle. The posterior leaflet of the mitral valve has a crescent shape and is attached to approximately three-fifths of the annular circumference. The posterior leaflet typically has two well-defined indentations which divide the leaflet into three individual scallops identified as P1(lateral scallop), P2(middle scallop), and P3(medial scallop). The three corresponding segments of the anterior leaflet are identified as A1(anterior segment), A2(middle segment), and A3(posterior segment). The leaflet indentations aid in opening the posterior leaflet during diastole.

As shown inFIG.1, the mitral valve has anterolateral and posteromedial commissures which define a distinct area where the anterior and posterior leaflets come together at their insertion into the annulus. Sometimes the commissures exist as well-defined leaflet segments, but often this area is a subtle structure that can be identified using the following two anatomic landmarks: (a) the axis of corresponding papillary muscles, and (b) the commissural chordae, which have a specific fan-like configuration. Several millimeters of valvular tissue separate the free edge of the commissures from the annulus.

The mitral valve is an atrio-ventricular valve separating the left atrium from the left ventricle. The mitral annulus constitutes the anatomical junction between the left ventricle and the left atrium. The fixed ends of the leaflets are attached to the annulus. The anterior portion of the mitral annulus is attached to the fibrous trigones and is generally more developed than the posterior annulus. The right fibrous trigone is a dense junctional area between the mitral valve, tricuspid valve, non-coronary cusp of the aortic valve, and the membranous septum. The left fibrous trigone is situated at the junction of both left fibrous borders of the aortic valve and the mitral valve.

The mitral annulus is less well developed at the insertion site of the posterior leaflet. This segment is not attached to any fibrous structures, and the fibrous skeleton in this region is discontinuous. This posterior portion of the annulus is prone to increase its circumference when mitral regurgitation occurs in association with left atrial or left ventricular dilation. The mitral annulus is saddle-shaped, and during systole the commissural areas move proximally, i.e. towards the roof of the atrium, while annular contraction also narrows the circumference. Both processes aid in achieving leaflet coaptation, which may be adversely affected by annular dilatation and calcification. The mitral annulus is surrounded by several important anatomic structures, including the aortic valve, the coronary sinus, and the circumflex artery. As a result, implanted cardiac devices at the mitral valve need to be positioned to accommodate the asymmetrical anatomy of the mitral valve without impacting the surrounding cardiac structures.

FIG.2is an isometric view showing an example of an implantable device200, such as a prosthetic leaflet device, which may be delivered to the heart using delivery systems according to the present technology. The implantable device200can be a prosthetic leaflet device having an atrial-fixation member202and a baffle214depending from the atrial-fixation member202in a downstream direction. The atrial-fixation member202can be configured to position and hold the baffle214at a desired location with respect to the native valve anatomy, and the baffle214is configured to displace at least a portion of a native leaflet of the cardiac valve and create a prosthetic coaptation surface for at least a portion of one or more of the other native leaflets of the cardiac valve. The baffle214can have a normally-closed clip220(see,FIG.4C) depending from its posterior surface which can be opened to engage the ventricular side of one of the native leaflets. A tendon (made of suture or nitinol wire) can actuate the clip by way of a lever attached to the clip. The lever may be a nitinol wire or laser cut nitinol or Co—Cr sheet. Additional implantable devices that can be used with delivery systems in accordance with the present technology are described in PCT/US2018/043566, which is incorporated herein in its entirety by reference. Any of several prosthetic valve replacement devices could similarly be used with delivery systems in accordance with the present technology, including complete mitral valve replacement devices. And, in addition to mitral valves, other valves such as tricuspid, aortic, and pulmonic valves could also be delivered using delivery systems in accordance with the present invention.

The implantable device200is configured relative to a flow axis VA in the direction of blood flow from the atrium to the ventricle and a transverse axis HA at an angle (e.g., orthogonal) to the flow axis VA. The implantable device200has a posterior side P, an anterior side A, a superior end S and an inferior end I. The implantable device200has a proximal or leading end which faces the atrium and a distal or trailing end which faces the ventricle. The uppermost row of struts of the atrial-fixation member202of the implantable device200includes a plurality of inverted V-shaped structures or crown points (e.g., chevrons)202V. One or more of the chevrons202V may each include a connector205at the apex of the inverted V-shaped crown points. The connectors205are sized to engage with a mating feature on the delivery system (described below).

The implantable device200may be inserted via a femoral vein sheath to traverse the inferior vena cava to the right atrium. The implantable device is then inserted into the left atrium via a puncture of the interatrial septum. In several applications, the implantable device200is desirably delivered to a target location within the mitral valve to function properly. This means appropriate positioning along the flow axis, correct radial positioning relative to the central axis of the valve, correct rotational orientation to specific landmarks such as the middle (P2) portion of the native posterior leaflet, and correct angular positioning relative to the flow axis and the transverse axis. The implantable device200may also need to be repositioned during the delivery process. For example, the implantable device200may initially be positioned distally into the left ventricle of the heart to engage one or more native valve leaflets, and then moved proximally towards the left atrium of the heart for final positioning before being released from the delivery system. Releasing the implantable device200from the delivery system should not exert excessive forces against the implantable device200or cause the implantable device200to move after being placed at the desired location and in the desired orientation relative to the native valve. Furthermore, the delivery system should allow the implantable device to be re-sheathed, repositioned, and/or removed before being released from the delivery system. Delivery systems of the present technology can achieve all the above-mentioned advantages in a user-friendly system. Additionally, several embodiments of delivery systems in accordance with the present technology have a small overall diameter, such as approximately 15 to 30 French.

FIGS.3A-3Cdepict an example of a distal portion of a delivery system300of the present technology. Referring toFIG.3A, the system300includes a delivery catheter302and an attachment assembly310configured to (a) securely retain the implantable device200as it passes through the vasculature (or through a guide that was previously placed through the vasculature and the atrial septum) and (b) selectively release the implantable device200at a desired target site. The delivery catheter302can have a proximal portion P and a distal portion D, and the attachment assembly310can be at the distal portion D of the delivery catheter302. The system300may optionally include at least one cinching tube CT containing a double-length suture loop CTS used to radially compress the atrial-fixation member202. The system300may further optionally include a tendon tube TT containing a double-length suture loop TTS used to open the clip on the posterior side of the baffle214. The tendon path may be configured so that actuating the tendon opens the clip. The optional cinching tube CT and tendon tube TT may extend through a lumen303in the delivery catheter302. It may also be possible to simply provide the suture CTS and TTS within lumens defined in the wall of the delivery catheter302or the central lumen of the delivery catheter302, with short, flexible tubes extending distally from the tip of the catheter to the implant.

Referring toFIG.3B, the attachment assembly310has a connector mechanism320and a locking mechanism330. The connector mechanism320can have a first actuator321(only a distal portion is shown), first arms322extending from a distal end of the first actuator321, and a connector324at the end of each first arm322. The first actuator321can be a first tube or first hub. The locking mechanism330can have a second actuator331(only a distal portion is shown), second arms332extending from the distal end of the second actuator331, and a retainer334at the end of each second arm332. The second actuator331can be a second tube or second hub. Each first arm322can be aligned with a corresponding second arm332such that the attachment assembly310has several pairs of first and second arms322and332, respectively. The first and second arms322and332can be directly superimposed over/under each other as shown, or they can be side-by-side, or they can have other suitable configurations. In the embodiment shown inFIG.3B, the attachment assembly310has eight arm pairs of first and second arms322/332, but it can have any number of arm pairs, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or more.

FIG.3Cis a detailed view showing the interface between a connector324and a retainer334of a single arm pair322/332. In some embodiments, the connector324is a C-shaped member having fingers325that extend from the corresponding first arm322and a central opening326between the distal ends of the fingers325. In some embodiments, the retainer334is a sleeve configured to slide over the connector324for moving from a locked position (shown inFIG.3C) to a release position (not shown) proximal of the locked position. The second arms332can have extensions335at their ends.

FIG.3Dis a detailed view of the interface between a connector205of an implantable device200(FIG.2), a connector324and a retainer334. The C-shaped configuration of the fingers325can be configured to receive the connector205of the implantable device200. For example, the connector205can have a head206configured to be retained between the fingers325and a neck207configured to extend through the opening326between the fingers325.FIG.3Dshows the retainer334in the locked position in which the retainer334securely retains the head206of the connector205between the fingers325. In the locked position, the retainer334prevents the connector205from disengaging the connector324. To move to the released position, the retainer334is positioned proximally relative to the connector324along the lengthwise dimension of the first arm322such that the head206and the neck207can disengage the connector324. For example, the first and second actuators321and331(FIG.3B) can move relative to each other such that the first and second arms322and332(FIG.3B) slide relative to each other along their lengthwise dimension. In one embodiment, the second actuator331is pulled proximally relative to the first actuator321such that the retainer334moves proximally relative to the connector324. In another embodiment, the first actuator321is pushed distally relative to the second actuator331such that the connector324moves distally relative to the retainer334. In either case, the connector324is positioned distal of the retainer334such that the connector205can disengage the connector324.

FIG.3Eis a detailed view of another configuration of the connecter324at the end of one of the first arms322and another configuration of the connector205of the implantable device200. In this embodiment, the connector324is a hooked-shaped member having a neck327and a head328, and the connector205is a mating hooked-shaped member having a neck207and a head206. The connector205mates with the connector324such that the heads328and206engage each other in a manner that prevents the implantable device200from disengaging the connector324when the retainer334is in the locked position shown inFIG.3E.

The first and second arms322and332may extend radially as shown inFIG.3B. Alternatively, the first and second arms322and332may extend in spiral arrangement such as with the attachment assembly310shown inFIG.3F. The spiral arrangement of first and second arms322and332may be more axially flexible when compressed into a delivery catheter than the radial delivery arms shown inFIG.3B.

The pairs of first and second arms322and332may all be the same length as shown inFIG.3C, or the pairs of first and second arm322and332may have different lengths at different locations around the delivery catheter302. For example, referring toFIG.3G, the pairs of first and second arms322and332on one side may be shorter than the pairs of first and second arms322and332on another side. In a specific example, the attachment assembly310can have anterior arm pairs322/332A and commissural arm pairs322/332C that are longer than posterior arm pairs322/332P. The commissural arm pairs322/332C can have a length between the lengths of the anterior and posterior arm pairs322/332A and322/332P, respectively. If the arm pairs have different lengths, the first and second actuators321and331, respectively, may be offset from the central axis of the valve, i.e., off-centered. For example, it may be preferable to have the first and second actuators321and331, respectively, closer to the posterior leaflet of the native mitral valve to better control the positioning of the implantable device200. If the arm pairs322/332are of different lengths, then as the implantable device200is collapsed into the sleeve, the atrial-fixation member202may be housed in the sleeve in a skewed orientation, which may allow the diameter of the implantable device200to be compressed further.

Although the system300is depicted with multiple pairs of first and second arms322and332, a single pair of first and second arms322and332may suffice. It will be appreciated that the first and second arms322and332may engage all the chevrons202V (FIG.2) described above, or only some of them (e.g., as few as a single chevron202V). The chevrons202V that are not attached to an arm pair can be shaped so that when the arms pull the implantable device200together into the sleeve, the non-attached chevrons also collapse into the sleeve at the same time.

FIGS.4A-4Fillustrate stages of delivering and deploying an implantable device200using an embodiment of the delivery catheter302and the attachment assembly310along with a steerable guide catheter410or series of coaxial guide catheters. Referring toFIG.4A, the guide catheter410can be inserted to traverse the venous system to the right atrium and then across the interatrial septum S into the left atrium LA. In some embodiments, the distal portion of the guide catheter410can be positioned so that its distal-most end (e.g., the end furthest from the user) is in the left atrium. For example, the guide catheter410can extend to a location as shown inFIG.4A, or the guide catheter410can be positioned further in the left atrium LA to extend at least generally along the flow axis of the native cardiac valve (e.g., a generally vertical axis VA inFIG.4A). This alignment can be achieved via a combination of torqueing the guide catheter410, pre-shaping the end of the guide catheter410, and the steerability features of the guide catheter410that configure the end of the guide catheter410to be deflected along one or more axes. However, in some embodiments, the guide catheter410may not have such complete steerability and its distal tip positioning may be more approximate such that additional positioning via the delivery catheter may be desired.

One optional steerability feature of the delivery catheter302is that it can be torqued to rotate the implantable device200for alignment with specific locations of the cardiac valve. Another optional steerability feature of the delivery catheter302adjusts the angle of the implantable device200to be angled with respect to the tip of the delivery catheter302(longitudinal axis). Various embodiments of such an angular steerability feature are described below with respect toFIGS.11A-13. The delivery system can also have a cover sleeve (not shown) positioned coaxially over the delivery catheter302and inside the guide catheter410. The cover sleeve can be advanced over the implantable device200to collapse the implantable device200for delivery, repositioning, and retrieval if desired. The cover sleeve may also be deflectable in one or more directions. Features such as a duck billed hemostasis valve can be incorporated at the proximal end of the guide catheter410to maintain hemostasis during and after introduction of the cover sleeve.

Referring toFIG.4B, the guide catheter410can be placed through the atrial septum S via a trans-femoral approach (or through the atrial roof in a trans-atrial approach). The steerable guide catheter410may be deflectable in one or more directions and can be advanced through the septum toward the mitral valve to facilitate optimal positioning of the implantable device200. The delivery catheter302can then be advanced through the steerable guide catheter410and into the left atrium LA.

Referring toFIG.4C, the arm pairs322/332are at least partially unsheathed such that they are positioned distally from the sheath of the delivery catheter302within the atrium. At this point, the atrial-fixation member202is partially expanded and a clip220coupled to the baffle214is exposed.

Referring toFIG.4D, the implantable device200can be oriented as desired by rotating the delivery catheter302within a cover sleeve of the delivery catheter302, rotating the cover sleeve within the guide catheter410, steering the cover sleeve and/or guide catheter410, and/or pulling/pushing control wires (not shown). As further shown inFIG.4D, the clip220coupled to the baffle214can be opened and positioned to capture the posterior leaflet between the clip220and the baffle214. When the implantable device200is rotationally and radially aligned, it can be advanced to the desired axial position within the native mitral valve. The clip220can be closed once it is positioned under the desired native leaflet. Cinching sutures (not shown) may be used to control the expansion of the atrial-fixation member202once it is positioned within the mitral valve. Alternatively, further unsheathing of the first and second arms322and332may provide a controlled final expansion of the implantable device200independent of cinching sutures.

FIG.4Eshows the process after the implantable device200has been fully expanded and the clip220has clamped the native leaflet to the baffle214. The performance of the implantable device200can then be evaluated via TEE echo imaging, and the implantable device200can be released, repositioned, or re-sheathed and removed. If the implantable device200is ready to be released, the cinch lines can be released and withdrawn through the delivery catheter302.

FIG.4Fshows the process after the attachment assembly310(FIGS.3A-3G) has been actuated such that the connectors205of the implantable device200have detached from the connectors324of the attachment assembly310. The delivery catheter302can then be removed through the guide catheter410, and then the guide catheter410can be withdrawn from the patient.

FIG.5Ais an isometric view of an attachment assembly510shown in a locked position andFIG.5Bis an isometric view of the attachment assembly510in a released position in accordance with the present technology. The attachment assembly510may be used in place of the attachment assembly310described above. The attachment assembly510includes a connector mechanism520having a first arm522, an opening523in the first arm, and a connector524. The connector524can be a spring wire having a base525(FIG.5B) and a latch526. The attachment assembly510can further include a locking mechanism530having a second arm532with a retainer534. The second arm532can be a tube, and the retainer534can be a distal portion of the tube. The first arm522of the connector assembly520can extend through a lumen of the second arm532.

In the locked position shown inFIG.5A, the second arm532covers the base525of the connector524such that the latch526is positioned through (a) a hole211in the connector205of the implantable device200and (b) the opening523at the distal portion of the first arm522. The latch526accordingly secures the connector205to the first arm522in the locked position. To move the attachment assembly510into the open position shown inFIG.5B, the first arm522is moved distally and/or the second arm532is moved proximally such that at least a portion of the base525of the connector524is free of the retainer534. The connector524can be formed from stainless steel, Nickel-Titanium alloys, or other suitable materials such that the base525moves the connector524to an open position (Arrow O) in which the latch526can disengage the opening523and the hole211. The connector205can then be disengaged from the connector mechanism520to deploy the implantable device200.

FIGS.6A and6Bdepict an attachment assembly610which may be used in place of the attachment assemblies310and510described above. The attachment assembly610can include a connector mechanism having a first arm622, an opening623through a distal portion of the first arm622, and a connector624attached to the first arm622. The connector624can include a base625attached to the first arm622, a latch626configured to be received through the hole211of the implantable device200and the opening623in the locked position, and a detent627between the base625and the latch626. The attachment assembly610can further include a locking mechanism having a second arm632and a driver634. The second arm632can have a slot626in which the base625of the connector624is received. In the embodiment shown inFIG.6A, the latch626is removed from the hole211and the opening623by moving the second arm632distally so that the driver634engages the detent627and moves the connector624outwardly.

FIG.7shows an attachment assembly710which may be used in place of the attachment assemblies310,510and610described above. The attachment assembly710includes an arm722and a connector724. The connector724can be a helically wound lock suture, cable, or wire726. A proximal end of the wire726is attached to an actuator outside the body, and the wire726extends along the arm722and through an eyelet728or the like at the distal of the arm722. The distal end of the wire726is wrapped around a portion of the implantable device200several times thereby securing the implant200to the delivery system300. The implantable device200is disengaged from the delivery system300by retracting the wire726, which unspools the wire from engagement with the implant200. The wire726may be formed of surgical grade stainless steel or a Nickel-Titanium alloy, such as Nitinol® or the like, which is pre-formed to a coil shape. If just one coil of the wire726is passed through the eyelet728and wrapped around implant200, the forces between the arm722and the implantable device200could potentially uncoil the wire726causing the two parts to prematurely separate. However, the implantable device200is better retained with multiple coils of the wire726passing through both the arm722and the implantable device200.

FIG.8depicts one arm pair of another attachment assembly810in accordance with the present technology. The attachment assembly810includes a connector mechanism having a first arm822with a connector824, and a locking mechanism having a second arm832with a retainer834. The first arm822can be a tube and the connector824can be an opening at the distal end of the first arm822. The second arm832can be a wire and the retainer834can be a distal portion of the wire. The connector205of the implantable device200has a head206configured to be received in the connector824and a neck207extending along the retainer834in the locked position. In operation the first arm822and/or the second arm832are moved such that the retainer834is positioned proximal of the head206. The head206can then disengage the connector824to release the implantable device200from the attachment assembly810. The connector205and the connector824may be formed of a resilient metal or plastic material including a super-elastic Nickel-Titanium alloy (Nitinol®). The arm pair shown inFIG.8is a single arm pair, and it will be appreciated that the attachment assembly810can have two or more arm pairs (e.g., 2, 3, 4, 5, 6, 7, 8 or more) as shown above inFIG.3B,3F or3G.

FIG.9Ashows a connector mechanism having a first arm322and a connector324in accordance with an embodiment of the technology, andFIG.9Bshows a connector205of the implantable device200for use with the connector324ofFIG.9A. Referring toFIG.9A, the connector324has fingers926extending from the distal portion of the first arm322and a ball928at the end of each finger926. The fingers926can be flexible wires, such as stainless steel or Nitinol®, and the proximal end of the fingers926can be attached to the first arm322by a hub929. The connector205of the implantable device200can include a hole211(FIG.9B).

FIG.9Cshows one arm pair of an attachment assembly910having (a) a locking mechanism including a second arm332and a retainer334defined by a distal portion of the second arm332, and (b) the connector mechanism shown inFIG.9B. The arm pair322/332shown inFIG.9Cis a single arm pair, and it will be appreciated that the attachment assembly910can have two or more arm pairs (e.g., 2, 3, 4, 5, 6, 7, 8 or more) arranged as shown above inFIG.3B,3F or3G.

FIG.9Cshows the attachment assembly910in a locked position in which the connector324(FIG.9A) is within retainer334while the balls928are positioned in the hole211of the connector205. The retainer334accordingly holds the balls928in the hole211to lock the implantable device200(FIG.2) to the attachment assembly910. The implantable device200is released from the connector324by moving the first arm322distally and/or moving the second arm332proximally such that the retainer334disengages the balls928. At this point, the fingers926can optionally spread apart from each other via an inherent spring force in the fingers926to disengage the balls928from the hole211.

FIG.10Ais a detailed cross-sectional view of an attachment assembly310in accordance with the present technology. The attachment assembly310has first and second arms322and332as described above. The first actuator321includes a first tube1010having a holder1012and a driver1020having a guide1022, and the holder1012and guide1022are arranged such that the holder1012is received in the guide1022. The driver1020further includes a threaded shaft1030. The second actuator331is a threaded bore1040engaged with the threaded shaft1030. In operation, the driver1020rotates one direction to move the second actuator331along the threaded shaft1030, which in turn moves the second arms332along the first arms322to move the retainer334with respect to the connector324(FIGS.3B and3C).

FIG.10Bis a detailed cross-sectional view of an attachment assembly310in accordance with the present technology. The attachment assembly310shown inFIG.10Bhas a first actuator321including a holder1012defined by a channel and a guide1022defined by a shoulder such that the guide1022is received in the holder1012. The attachment assembly310shown inFIG.10Balso includes a driver1020coupled to a threaded shaft1030and a second actuator331having a threaded bore1040engaged with the threaded shaft1030. The attachment assembly310shown inFIG.10Boperates analogously to the attachment assembly310shown inFIG.10A. Additionally,FIG.10Bshows a cinch tube CT or tendon tube TT that houses the suture lines for cinching the implantable device during delivery. The cinch tube CT or tendon tube TT can be a coiled tube.

FIGS.11A-11Care enlarged views of universal joints in accordance with the present technology that are configured to steer the attachment assembly in multiple directions. Like reference numbers refer to like components inFIGS.11A-110.FIG.11Ashows an example universal joint1110awhich includes a spacer1112, first hinges1120a, second hinges1120b, first control wires1130a, and second control wires1130b. The first and second hinges1120aand1120bcan be flexible posts made from a metal (e.g., stainless steel or Nickel-Titanium alloy such as Nitinol®). The first hinges1120aconnect the spacer1112to the delivery catheter302, and the second hinges1120bconnect the spacer1112to the attachment assembly310. The first and second hinges1120aand1120bcan be offset from each other relative to the circumference of the spacer. For example, the first and second hinges1120aand1120bcan be offset by 180 degrees or another suitable orientation. The spacer1112can have holes1114through which the first and second control wires1130aand1130bpass. The first control wires1130acan be attached to the first actuator321and the second control wires1130bcan be attached to the second actuator331. The control wires1130aand1130bmay also extend through a central lumen of the delivery catheter302or through one or more auxiliary lumens formed in the sidewall of the delivery catheter302. The control wires1130aand1130bmay be flexible or rigid such that they may be pushed and/or pulled to transmit steering forces to the attachment assembly310.

In operation, the first and second control wires1130aand1130bcan be manipulated to change the angular orientation of the attachment assembly310. For example, the first and second control wires1030aand1030bcan be pulled/pushed so that the attachment assembly310pivots with respect to the spacer1012.

FIG.11Bshows an example universal joint1110bincluding a ball1140and a socket1150which cooperatively form a ball-socket joint. The ball1140is attached to the second actuator322and the socket1150is attached to, or integrally formed with, the delivery catheter302. The delivery catheter302can include a central lumen, and the socket1150can be an enlarged portion of the central lumen that is slightly larger than the ball1140. The control wires1130aand1130acan extend through the delivery catheter302, such as through one or more auxiliary lumens formed in the sidewall of the delivery catheter302. The ball-socket universal joint1110ballows the attachment assembly310to tilt relative to the longitudinal axis of the delivery catheter302while enabling the delivery catheter302to torque the attachment assembly310. The first and second arms322and332are re-oriented by torqueing the delivery catheter302and by pulling/pushing on one or more of the control wires1130aand1130b.

FIG.11Cshows an example universal joint1110cincluding a flexible inner shaft1160attached to or integrally formed with the attachment assembly310at a flexible joint1162. The flexible inner shaft1160can be coaxially received in a central lumen303of the delivery catheter302. The universal joint1110ccan further include at least two control wires1130aand1130bhaving distal ends slideably received in arcuate slots1164aand1164b, respectively, formed in the attachment assembly310. The control wires1130aand1130bextend through the delivery catheter302to an actuator outside of the patient (not illustrated). The arcuate slots1164aand1164ballow the control wires1130aand1130bto move relative to the inner shaft1160so the steering direction can remain constant even when the distal tip is rotated.

The control wires1130aand1130bmay extend through one or more lumens formed in the sidewall of the delivery catheter302. The control wires1130aand1130bmay be flexible or rigid such that a pushing force may be transmitted to the attachment assembly310. In operation, the attachment assembly310is orientated to a desired position by torqueing the inner shaft1160and by pulling/pushing on one or more of the control wires1130aand1130b.

FIG.12is a detailed view of an attachment assembly310in accordance with the present technology. The attachment assembly310shown inFIG.12has a universal joint1200that defines a portion of the first actuator321. The universal joint1200has a first band1210, a second band1212, and a third band1214. In the illustrated embodiment, the first band1210is an upper band that can be at a distal portion of an outer tube, the third band1214is a lower band from which the first arms322can extend, and the second band1212is a middle band between the first and third bands1210and1214. The universal joint1200further includes a first flexible joint1216between the first band1210and the second band1212and a second flexible joint1218between the second band1212and the third band1214. The first and second flexible joints1216and1218are offset relative to each other by an amount, such as 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135° or 150°. In many cases, the first and second flexible joints1216and1218can be offset from each by 90° as shown inFIG.12. The first band1210can have first through holes1220aand1220b, and the second band1212can have a through hole1222. The attachment assembly310can further include a control wire1230aand a control wire1230b. The control wire1230apasses through the holes1220aand1222and is attached to the third band1214opposite the second flexible joint1218. The control wire1230bpasses through the through hole1220aand is attached to the second band1212opposite the first flexible joint1216. The attachment assembly310can also include a second actuator331defined by a tube that passes through the universal joint1200and second arms332that extend from the second actuator331.

In operation, the attachment assembly310can be angularly orientated by manipulating the control wires1230aand1230b. For example, the control wire1230acan be pulled/pushed such that second flexible joint1218bends and the third band1214moves in a plane of the second flexible joint1218(shown by arrow M inFIG.12), and/or the control wire1230bcan be pulled/pushed such that the first flexible joint1216bends and the second band1212moves in a plane of the first flexible joint1216(orthogonal to the plane of arrow M). This allows an operator to angularly position the attachment assembly310while the implantable device200is proximate the heart valve.

FIG.13is a detailed view of an attachment assembly310in accordance with the present technology. The attachment assembly310shown inFIG.13has a ball-type universal joint1300that defines a portion of the first actuator321. The universal joint1300can include a cup1310, a ball1312configured to be rotatably contained by the cup1310, and an opening1314through the ball1312. The cup1310can be a distal portion of an outer tube that defines the first actuator321, and the ball1312can define a hub from which the first arms322extend. The second actuator331can extend through the opening1314of the ball1312, and the second arms332can extend from the second actuator331. In operation, one or both of the first and second actuators321/331can be pushed/pulled to move the first and/or second arms322/332relative to each other to release implantable device from the attachment assembly310. The angular orientation of the ball1312with respect to the cup1310can be controlled using one or more control wires1330aand/or1330bat different circumferential locations of the ball1312.

In any of the examples disclosed herein, the control wires1030a/b,1130a/b,1230a/band1330a/b(collectively “control wires”) may be a rod, a cable (braided wire), or wire. The control wires may be attached to or integrally formed with the attachment assembly310. The control wires may be formed of a biocompatible material such as surgical grade stainless steel or a super elastic Nickel-Titanium alloy such as Nitinol®.

EXAMPLES

Various examples of aspects of the subject technology described above with reference toFIGS.3A-13are provided as numbered clauses (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the subject technology.

1. A delivery system for implanting a medical device, comprising:a delivery catheter having a proximal portion and a distal portion;a connector mechanism having first arms and connectors, each first arm has a proximal portion coupled to the delivery catheter and a distal portion, and each connector is at the distal portion of a corresponding first arm and configured to engage the medical device;a locking mechanism having second arms and retainers, each second arm has a proximal portion coupled to the delivery catheter and a distal portion, and each retainer is at the distal portion of a corresponding second arm and configured to maintain engagement between the connector and the medical device in a locked position; andwherein each first arm is associated with a corresponding second arm to define pairs of first and second arms in which the first arm and/or the second arm move relative to each other to a released position in which the retainer of the second arm is moved from the connector of the corresponding first arm to release the medical device.

2. The delivery system of clause 1 wherein the delivery catheter has a first actuator and a second actuator, and wherein the first arms are coupled to the first actuator, the second arms are coupled to the second actuator, and the first actuator and/or second actuator can move relative to the other.

3. The delivery system of any of clauses 1-2 wherein the connector mechanism has at least 3 first arms and the locking mechanism has at least 3 second arms.

4. The delivery system of any of clauses 1-3 wherein the first arms and the second arms are substantially straight.

5. The delivery system of any of clauses 1-3 wherein the first arms and the second arms are curved.

6. The delivery system of any of clauses 1-5 wherein the connectors have fingers configured into a C-shape and the retainers are sleeves that fit over the C-shaped fingers in the locked position.

7. The delivery system of any of clauses 1-5 wherein the connectors having a head and a neck, and the retainers are sleeves that fit over the heads in the locked position.

8. The delivery system of any of clauses 1-5 wherein each first arm has an opening and the connectors are spring wires, and each spring wire has a base coupled to a corresponding first arm and a latch configured to be in the opening in the locked position.

9. The delivery system of any of clauses 1-5 wherein each first arm is a tube and the connector is an opening at a distal portion of the tube, and each second arm is a rod within the tube and the retainer is a distal portion of the rod.

10. The delivery system of any of clauses 1-5 wherein each connector comprises at least one flexible finger and a ball attached to the finger, and each second arm comprises a tube with the retainer comprising a distal portion of the tube.

11. The delivery system of any of clauses 1-10, further comprising a universal joint between the delivery catheter and the first and second arms.

12. The delivery catheter of any of clauses 11 wherein the universal joint has a plurality of control wires, a spacer between the delivery catheter and the first and second arms, and flexible hinges coupling one side of the spacer to the delivery catheter and another side of the spacer to the first and second arms.

13. The delivery system of any of clauses 12 wherein the flexible hinges include a first set of hinges coupling the one side of the spacer to the delivery catheter and a second set of hinges coupling the other side of the spacer to the first and second arms, and wherein the first set of hinges are circumferentially offset from the second set of hinges.

14. The delivery system of any of clauses 11 wherein the universal joint has a ball coupled to the first and second arm and a socket in the delivery catheter configured to receive the ball.

15. The delivery system of any of clauses 11 wherein the universal joint has a flexible inner shaft coupled to the first and second arms and control wires.

16. A delivery system for placing an implantable device, comprising:a delivery catheter having a proximal portion and a distal portion; andan attachment assembly having arm pairs in which individual arm pairs include a first arm with connector and a second arm with a retainer, wherein (a) each first arm extends along a corresponding second arm, and (b) the first arm and/or the second arm moves relative to the other from a locked position in which the retainer interfaces with the connector to maintain engagement between the implantable device and the connector to a released position in which the retainer is positioned relative to the connector such that the implantable device can disengage the connector.

17. The delivery system of clause 16 wherein the connector mechanism has at least 3 first arms and the locking mechanism has at least 3 second arms.

18. The delivery system of any of clauses 16-17 wherein the first arms and the second arms are substantially straight.

19. The delivery system of any of clauses 16-17 wherein the first arms and the second arms are curved.

20. The delivery system of any of clauses 16-19 wherein the connectors have fingers configured into a C-shape and the retainers are sleeves that fit over the C-shaped fingers in the locked position.

21. The delivery system of any of clauses 16-19 wherein the connectors having a head and a neck, and the retainers are sleeves that fit over the heads in the locked position.

22. The delivery system of any of clauses 16-19 wherein each first arm has an opening and the connectors are spring wires, and each spring wire has a base coupled to a corresponding first arm and a latch configured to be in the opening in the locked position.

23. The delivery system of any of clauses 16-19 wherein each first arm is a tube and the connector is an opening at a distal portion of the tube, and each second arm is a rod within the tube and the retainer is a distal portion of the rod.

24. The delivery system of any of clauses 16-19 wherein each connector comprises at least one flexible finger and a ball attached to the finger, and each second arm comprises a tube with the retainer comprising a distal portion of the tube.

25. The delivery system of any of clauses 16-24, further comprising a universal joint between the delivery catheter and the first and second arms.

26. The delivery catheter of any of clauses 25 wherein the universal joint has a plurality of control wires, a spacer between the delivery catheter and the first and second arms, and flexible hinges coupling one side of the spacer to the delivery catheter and another side of the spacer to the first and second arms.

27. The delivery system of any of clauses 26 wherein the flexible hinges include a first set of hinges coupling the one side of the spacer to the delivery catheter and a second set of hinges coupling the other side of the spacer to the first and second arms, and wherein the first set of hinges are circumferentially offset from the second set of hinges.

28. The delivery system of any of clauses 25 wherein the universal joint has a ball coupled to the first and second arm and a socket in the delivery catheter configured to receive the ball.

29. The delivery system of any of clauses 25 wherein the universal joint has a flexible inner shaft coupled to the first and second arms and control wires.

30. The delivery system of any of clauses 1-29 wherein the delivery catheter has a first actuator and a second actuator, and wherein the first arms are coupled to the first actuator, the second arms are coupled to the second actuator, and the first actuator and/or second actuator can move relative to the other.

From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but that various modifications may be made without deviating from the disclosure. Accordingly, the invention is not limited except as by the appended claims. Furthermore, certain aspects of the new technology described in the context of particular embodiments may also be combined or eliminated in other embodiments. For example, instead of the mechanical connection mechanisms and locking mechanism described above, the attachment assemblies can have electrolytic detachment mechanisms at the end of each first arm. Moreover, although advantages associated with certain embodiments of the new technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.