Valve clamp for device delivery catheter handle

In some examples, an implantable medical device delivery catheter comprises a handle and an elongated member disposed within the handle, the elongated member comprising an elongated member lumen configured to receive an inner tool that is configured to extend through a lumen of the delivery catheter, including the elongated member lumen, and interface with an implantable medical device. The handle further comprises a clamping assembly comprising a button configured to be actuated toward a longitudinal axis of the elongated member in a direction transverse to the longitudinal axis to compress the elongated member against the inner tool to restrain movement of the inner tool through the elongated member lumen.

TECHNICAL FIELD

This disclosure relates generally to medical devices, and, more particularly, to systems for delivering medical devices.

BACKGROUND

Some types of implantable medical devices (IMDs), such as cardiac pacemakers or implantable cardiac defibrillator systems, may be used to provide cardiac sensing and therapy for a patient via one or more electrodes. Some IMDs include an implantable pulse generator that includes a housing that encloses electronic components, which may be configured to be implanted subcutaneously in the chest of the patient or within a chamber of a heart of the patient, as examples. IMDs having a pulse generator that is configured to be implanted within a chamber of the heart may be referred to as an intracardiac device or a leadless implantable medical device. A delivery catheter may be used to deliver an intracardiac device transvenously to an implant site within a heart of a patient and release the device after the device has been fixed at the implant site. The delivery catheter then may be withdrawn from the patient.

SUMMARY

In general, this disclosure is directed to delivery catheters and delivery systems for delivering an IMD within a vasculature of a patient. In some examples, a delivery system includes a delivery catheter that comprises a delivery catheter lumen, and an inner tool that may slidably extend through the delivery catheter lumen. The delivery catheter includes a handle, with an elongated member disposed within the handle. The elongated member defines an elongated member lumen, which is part of the delivery catheter lumen through which the inner tool may slidably extend. The handle also includes a clamping assembly configured to be actuated to selectively compress or pinch the elongated member against the inner tool in order to, for example, restrict movement of the inner tool through the elongated member lumen (and thereby through the delivery catheter lumen) or otherwise secure the inner tool in place within the delivery catheter lumen.

In one example, an implantable medical device delivery catheter comprises a shaft configured to extend through a vasculature of a patient, wherein the shaft comprises a shaft lumen extending from a proximal end of the shaft to a distal end of the shaft, and a handle connected to the proximal end of the shaft. The handle comprises an elongated member disposed within the handle, the elongated member comprising an elongated member lumen in fluid communication with the shaft lumen, wherein the elongated member lumen and the shaft lumen are configured to receive an inner tool configured to extend through the elongated member lumen and the shaft lumen and interface with the implantable medical device. The handle further comprises a clamping assembly comprising a button configured to be actuated toward a longitudinal axis of the elongated member in a direction transverse to the longitudinal axis to compress the elongated member against the inner tool to restrain movement of the inner tool through the elongated member lumen.

In another example, a method comprises engaging a clamping assembly of a handle of a medical device delivery catheter for a first time to restrain movement of an inner tool through an elongated member lumen of an elongated member disposed within the handle, wherein engaging the clamping assembly comprises actuating a button of the clamping assembly toward a longitudinal axis of the elongate member in a direction transverse to the longitudinal axis to compress the elongated member against the inner tool. The method further comprises, with the clamping assembly engaged for the first time, introducing a distal end of a shaft of the delivery catheter into a vasculature of a patient toward a tissue site, wherein the shaft comprises a shaft lumen extending from a proximal end of the shaft to a distal end of the shaft, wherein the handle is connected to the proximal end of the shaft, wherein the shaft lumen is in fluid communication with the elongated member lumen, wherein the shaft lumen and the elongated member lumen are configured to receive the inner tool, and wherein the inner tool is configured to interface with an implantable medical device. The method further comprises releasing the clamping assembly, wherein releasing the clamping assembly comprises actuating the button of the clamping assembly away from the longitudinal axis of the elongate member and, with the clamping assembly released, actuating the inner tool, wherein actuating the inner tool comprises moving the inner tool through the shaft lumen and the elongated member lumen. The method further comprises, after actuating the inner tool, engaging the clamping assembly a second time to restrain movement of the inner tool through the elongated member lumen and, with the clamping assembly engaged the second time, proximally withdrawing the shaft from the patient.

In another example, a system comprises an implantable medical device delivery catheter as described herein and an inner tool.

This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the apparatus and methods described in detail within the accompanying drawings and description below. Further details of one or more examples are set forth in the accompanying drawings and the description below.

DETAILED DESCRIPTION

In general, this disclosure describes devices and systems for introducing an implantable medical device (IMD) within a vasculature or other anatomy of a patient.FIG.1is a side view illustrating an example delivery system10for introducing an IMD, such as a pacemaker, within a vasculature or other anatomy of patient. System10includes inner member48and outer member16. Although described herein in the context of delivering an IMD into the vasculature, e.g., heart, the devices, systems, and techniques of this disclosure may be used to deliver an IMD to any anatomical location.

Outer member16(also referred to as an “introducer”) is an elongated tubular member defining an interior lumen. Outer member16includes proximal end32and distal end50. Outer member16is configured to be inserted, such as by a physician, into a vasculature of a patient to provide a rigid channel (lumen) through which to insert a medical instrument, device, or other therapy.

Inner member48(also referred to as a “delivery catheter”) is configured to be inserted through the lumen of outer member16to deliver a medical device within the vasculature. Inner member48includes elongated shaft12, handle14, and device cup18. Handle14is connected to a proximal end of shaft12, and may include one or more elements52configured to control the motion of the distal end of shaft12. In some examples, handle14includes side port46, for connection to a flushing assembly.

Device cup18is disposed at a distal end of shaft12. Device cup18includes a hollow cylindrical body configured to house and support an IMD while the IMD is being implanted within a vasculature of a patient. For example, a physician may insert the distal end of inner member48, including device cup18, through the lumen of outer member16, which is disposed within a vasculature of a patient. Once device cup18has extended through distal end50of outer member16and reached an implant site within the patient, the physician may release the IMD from distal opening44of device cup18, for example, by actuating inner tool40, e.g., moving inner tool40(e.g., a mechanical tether) through the shaft lumen56(FIG.2A) of shaft12to advance the IMD through distal opening44and releasing the IMD from a distal end of inner tool40. The physician may then withdraw shaft12and cup18proximally through outer member16.

Inner tool40may slidably extend through a delivery catheter lumen (not shown inFIG.1) of delivery catheter48. It is to be understood that, although the present disclosure primarily describes examples in which inner tool40is a mechanical tether which is configured to release an IMD into a patient's anatomy, the disclosed techniques function similarly with respect to other inner tools configured to be advanced/retracted through a lumen defined by delivery catheter48, such as a snare configured to retrieve an IMD from within a patient's anatomy. Hence, inner tool refers generally to a variety of mechanical components configured to interact with an IMD.

In some examples, delivery catheter lumen is defined by shaft lumen56(FIG.2A) and one or more lumen of handle14, such as a hub lumen58defined by a hub20(FIG.3A) and valve lumen62defined by a valve28(FIGS.3D-3F,4B and4C). Valve28, or components thereof described herein, are examples of an elongated member within handle14, and valve lumen62, or the lumen of a component of the valve, are examples of an elongated member lumen configured to slidably receive inner tool40. The handle lumen (e.g., including valve lumen62or another elongated member lumen) may be in fluid communication with shaft lumen56in order to define a continuous catheter lumen configured to slidably receive inner tool40. In general, an elongated member may be a deformable (e.g., elastically deformable) structure defining a lumen, such as a tube, which may be formed from an elastically deformable material.

As will be described herein, handle14may include a clamping assembly38configured to be actuated to compress or pinch an elongated member within handle against inner tool40within the elongated member lumen, e.g., valve28and valve lumen62. In this manner, the clamp may prevent or otherwise restrict longitudinal movement of inner tool40or another inner tool through the delivery catheter lumen. Features of clamping assembly38described herein may facilitate intuitive one-handed user actuation in a direction toward a longitudinal axis of the elongated member to engage the clamping assembly, locking the clamping assembly in the engaged position, and unlocking and disengaging the clamping assembly. In this manner, clamping assembly38may provide better control over the device delivery system, and in some examples, may enable the physician to implant or retrieve an IMD without requiring an assistant to operate either handle14or tool40.

FIGS.2A and2Bare perspective views of the proximal portion of delivery catheter48, depicting handle14connected to a proximal end of shaft12.FIGS.2A and2Binclude the x-y-z orthogonal coordinate system to serve as a frame of reference. In some examples in accordance with techniques of this disclosure, handle14includes a clamping assembly38configured to secure and retain inner tool40(such as a mechanical tether or snare) in place with respect to handle14, e.g., to selectively prevent or allow movement of inner tool40through a lumen of delivery catheter48in the direction of the y-axis. In the illustrated example, clamping assembly38is located at a proximal end of handle14, but may be located at other positions along handle14in other examples. Clamping assembly38may also create a redundant hemostatic seal for system10. Clamping assembly38may be disposed in an “open” or unlocked position, as shown inFIG.2A, or in a “closed” or locked position, as shown inFIG.2B.

Clamping assembly38includes clamp button26. Clamp button26is movable, e.g., in the negative-z-axis-direction, from the open position (FIG.2A) to the closed position (FIG.2B) in order to compress or pinch a valve28(e.g., a clamp tube60of valve28) closed around inner tool40. In other words, button26is configured to be actuated toward a central longitudinal axis of delivery catheter48, e.g., of valve28and/or clamp tube60, in a direction that is substantially transverse (normal) to the central longitudinal axis. The friction between valve28(for example, composed of a polymer such as rubber) and inner tool40when clamp button26is in the closed position and has deformed valve28may reduce or prevent any movement of inner tool40with respect to valve28, such as proximally or distally along the y-axis direction. Clamp button26is also movable, e.g., in the positive-z-axis-direction, from the closed position (FIG.2B) to the open position (FIG.2A) to release inner tool40. In other words, button26is configured to be actuated away from the central longitudinal axis of delivery catheter48, in a direction that is substantially transverse (normal) to the central longitudinal axis. More specifically, as described further below, button26is configured to be actuated away from the central longitudinal axis of delivery catheter48in response to an applied pressure that is parallel with the central longitudinal axis in a direction of the distal end of delivery catheter48. In this arrangement, the physician may easily actuate button26with the same hand holding handle14, leaving his or her other hand free to hold the position of the shaft of delivery catheter48relative to the proximal end32of outer member16(thereby maintaining forward pressure on the delivery cup18) without need for an assistant. Once button26is unlocked, that hand can then control tool40.

FIGS.3A-3Dare perspective views of the proximal portion of the medical device delivery catheter48ofFIG.1with a portion of the outer housing removed to illustrate one or more interior components. Specifically,FIGS.3A-3Dillustrate handle14having clamping assembly38.FIGS.3A and3Bdepict clamping assembly38in an “open”, “unlocked”, or “first” configuration.FIGS.3C and3Ddepict clamping assembly38in a “closed”, “locked”, or “second” configuration.

Clamping assembly38includes hub20, valve cap portions30A-30C (collectively referred to as “valve cap30”), and button26. In some examples, shaft12may extend proximally through handle14and connect to hub20. Hub20may be a relatively rigid (e.g., plastic) material configured to connect shaft12to valve28. In some examples, hub20may define a single inner hub lumen58extending through handle14. In other examples, hub20may include a more complex shape, defining multiple branching lumens. For example, as illustrated by the example ofFIG.3A, hub20may define a secondary lumen64leading to side port46for connection to a flushing assembly.

Valve28is an elongated tubular member disposed inside a proximal portion of handle14. Valve28(also referred to as “elongated member28”) defines an interior lumen (e.g., valve lumen62shown inFIGS.4B and4E, which may also be referred to as an elongated member lumen) in fluid communication with lumen58of hub20. In some examples, valve28extends from the proximal end of handle14to shaft12at the distal end of handle14. In other examples, valve28is disposed near the proximal end of handle14, and is connected to another distinct elongated member, such as hub20, extending the rest of the way through handle14.

Valve28is composed of a relatively soft and/or springy material, e.g., an elastomeric material that tends to elastically return to its original shape or configuration after a compressive or distorting force has been removed. In some examples, valve28comprises a polymer, such as rubber.

Lumen62of valve28is configured to slidably receive, in at least some examples, an elongated inner tool40. Inner tool40may comprise a string or cable-like element and be configured to attach, at its distal end, to an IMD located distal to the distal end of shaft12, e.g., within or outside of the distal opening of delivery cup18. Inner tool40may be configured to move proximally or distally through the lumen of valve28. Inner tool40may include, for example, a mechanical tether configured to implant the IMD within a vasculature of a patient. In other examples, inner tool40may include a snare configured to retrieve the IMD from within the vasculature of the patient. In these examples, actuating inner tool40includes grabbing the IMD with a distal end of the snare.

The proximal end of valve28defines clamp tube60, which may be an elongated member in some examples. Clamp tube60is an elongated extension of valve28, configured in the manner described with respect to valve28to be compressed such that lumen62defined by valve28and clamp tube60pinches, or collapses around, inner tool40, securing inner tool40in place via friction. Clamp tube60may partially extend out a proximal end of handle14.

Valve cap30is a relatively rigid and/or durable (e.g., comprising a plastic) element configured to support and align the various other components of clamping mechanism38. Valve cap30includes at least three sub-components30A-30C, respectively, however, the three components may be molded or formed from a single unit, or from separate units and subsequently welded or otherwise joined together. Valve cap30is described further with respect toFIGS.3E and3F, below.

Clamp button26is an element formed from one or more relatively hard or durable materials (e.g., a plastic) configured to pinch and hold clamp tube60closed around inner tool40. Clamp button26includes spade36, proximal-facing teeth22, and grips54.

Spade36(shown inFIGS.3B and4A-4C) is a protrusion extending radially (e.g., in the negative-z-axis direction), or transverse to a longitudinal axis of handle14, and toward clamp tube portion60of valve28. Spade36is configured to contact and compress (or pinch) the outer surface of clamp tube portion60of valve28. In some examples, spade36may be shaped similar to the head of a shovel, in that it is relatively thin along one axis (e.g., along the longitudinal axis of handle14), so as to decrease the surface area of spade36contacting the outer surface of clamp tube60, and accordingly, increase the pressure applied to clamp tube60. For similar reasons, spade36may define a rounded tip configured to contact the outer surface of clamp tube60. In other examples, spade36may define a substantially flat tip, which may be oriented perpendicular to the longitudinal axis of handle14.

Clamp button26defines a pair of sets of proximal-facing teeth22, one set disposed on either side (e.g., along the x-axis direction) of clamp button26. Proximal-facing teeth are configured to secure clamp button26in the “locked” position, for example, by engaging with corresponding sets of distal-facing teeth24defined by the housing of handle14. When placed in the “locked” position (FIGS.3C and3D), the soft (e.g., springy) composition of clamp tube60may press and hold proximal-facing teeth22proximally against distal-facing teeth24, engaging the sets of teeth with one another.

In order to place clamping assembly38in the “locked” position shown inFIGS.3C and3D, a user may apply downward pressure (e.g., in the negative-z-axis direction) to the top of clamp button26. This downward pressure will cause spade36, extending from button26, to depress downward into the material of clamp tube60, elastically deforming the material of the tube and collapsing its inner lumen. In some examples, the outer surface of clamp tube60may define an inclined or ramp-like geometry, e.g., tapered or declining in a proximal direction. Accordingly, in response to the downward compressive force, the material of clamp tube60may elastically apply a restoring force against spade36, in both proximal (negative-y-axis) and upward (z-axis) directions in such examples. The proximal and upward restoring force will press proximal-facing teeth22against distal-facing teeth24, securing clamp button26in place, holding clamp tube60closed underneath spade36, and securing mechanical tether40in place.

In order to release clamp button26back to the “unlocked” position (FIGS.3A and3B), the user may apply distal pressure (e.g., in the y-axis direction, toward the distal end of shaft12) to clamp button26, disengaging the two sets of teeth. In this manner, button26is configured to be actuated from the second “locked” position to the first “unlocked” position in response to a longitudinal force in a direction of the distal end of the catheter. The rubbery or springy composition of clamp tube60will tend to press clamp button26upward (e.g., in the z-axis direction), and back to the “unlocked” position. In some examples, the user may advantageously actuate the button between the locked and unlocked positions with one hand.

FIGS.3E and3Fare perspective views of the proximal portion of the medical device delivery catheter ofFIG.1with a portion of the housing, as well as the clamp button26removed, in order to illustrate one or more inner components. Specifically,FIGS.3E and3Fillustrate valve cap components30A-30C. Valve cap30is a relatively rigid or durable (e.g., composed of plastic) element configured to support and align the various other components of clamping mechanism38with respect to one another. During assembly, valve cap30fits over valve28and snaps onto hub20. Valve cap30includes at least three structural components30A-30C, respectively, however, the three components may be molded or formed from a single unit, or from separate units and subsequently welded or otherwise joined together. In the illustrated example, valve cap30includes ring30A, lock30B, and half-pipe30C.

Ring30A includes one or more circular or ring-like structures. As shown inFIG.3E, ring30A may include two ring-shaped structures of different diameters, configured to join (and/or hermetically seal) valve28with hub20. For example, ring30A may include a larger-diameter ring structure configured to match a diameter of the proximal end of hub20, and a second, smaller-diameter ring structure configured to match or house a distal end of valve28.

Lock30B is a U-shaped or horseshoe-shaped structure extending distally (e.g., in the y-axis direction) from ring30A. Lock30B is configured to receive and surround locking bump42. Locking bump42is a protrusion extending radially (e.g., in the x-axis directions) from hub20. By surrounding locking bump42, lock30B may secure hub20in place with respect to valve cap30, for example, preventing separation between the two components in the y-axis direction. In some examples, lock30B defines a rectangular central opening configured to receive locking bump42, which may also be generally rectangle-shaped.

Half-pipe30C is a semi-cylindrical element extending proximally (e.g., in the negative y-axis direction) from ring30A. Half-pipe30C is configured to receive and support an underside of clamp tube60. For example, when clamping assembly38is engaged (e.g., in the “locked” position), clamp tube60may be compressed between half-pipe30C on the underside and spade36on the top side.

FIG.3Ffurther depicts the underside of half-pipe30C. In some examples, half-pipe30C defines pinch window34. Pinch window34is an opening, such as a rectangular opening, configured to receive a portion of clamp tube60when clamp assembly38is in a “locked” position. For example, pinch window34may be disposed directly opposite from spade36, such that spade36forces or presses a portion of clamp tube60downward (in the negative z-axis) into pinch window34. As shown inFIGS.4A-4C, the deformation of clamp tube60into pinch window34provides a more tortuous path for inner tool40through the lumen of clamp tube60. The more tortuous path may provide more contact area and contact force between inner tool40and clamp tube60, increasing the amount of friction between the elements and securing mechanical tether40more firmly in place.

FIGS.4A-4Care cross-sectional views of handle14of the delivery catheter48ofFIG.1. Specifically,FIGS.4A-4Cillustrate clamping mechanism38of handle14, configured in a “locked” configuration. In the “locked” configuration, clamp button26has been pressed in the negative-z-axis direction, forcing spade36downward into the outer surface of clamp tube60, which may be the proximal end of valve28. In response, the flexible material of clamp tube60compresses or deforms, collapsing or pinching its inner lumen around inner tool40. A portion of clamp tube60deforms into pinch window34of half-pipe30C, further deforming the inner lumen of clamp tube60. Accordingly, inner tool40is forced to bend or curve in the region between spade36and pinch window34. This bending of inner tool40further reduces or prevents any proximal or distal motion of inner tool40through the inner lumen of clamp tube60.

FIGS.5A-5Dillustrate another example medical device delivery catheter66, in accordance with the techniques of this disclosure. Delivery catheter66may be an example of inner member or delivery catheter48ofFIGS.1-4C. Like numbered elements inFIGS.5A-5Dmay be configured and function in a substantially similar manner to that described with respect toFIGS.1-4C, except as noted herein.FIG.5Ais a perspective view of delivery catheter66,FIG.5Bis an exploded view of catheter66,FIG.5Cis a longitudinal cross-sectional side view of catheter66, andFIG.5Dis a cross-sectional end view of catheter66as viewed from axis B-B ofFIG.5C.

As shown inFIG.5A, delivery catheter66includes a handle14(e.g., handle14ofFIGS.1-4C) having an additional rotary mechanism68to assist a user to depress button76(FIG.5B) radially inward into valve28, so as to clamp valve28shut around an inner tool40(FIG.1). As shown in the exploded view ofFIG.5B, rotary mechanism68includes inner cam lock ring70, outer cam lock72, and button76. Handle14further includes tip button52, housing portions74A and74B and pull block78. Housing portions74A and74B contain the internal components of handle14, such as valve28, button76, and inner cam lock ring70. Pull block78serves to slidably connect tip button52to a distal end of catheter66, such as via pull wire84.

During use, a user such as a physician may apply rotational pressure to rotary mechanism68, via outer cam lock72, which is rigidly coupled to inner cam lock ring70. As shown in greater detail inFIGS.6A and6B, inner cam lock ring70includes curvilinear inner edge80configured to contact button76. Curvilinear inner edge80defines a portion of a spiral pattern, such that the radius of curvature of curvilinear inner edge80decreases from first radius “R” to second radius “r” along a counter-clockwise direction, from the perspective shown inFIG.6A. Accordingly, as the user rotates outer cam lock72in a clockwise direction, the portion of inner edge80that contacts button76decreases in radius of curvature, causing button76to depress radially inward toward valve28, causing valve28to collapse around inner tool40, thereby securing inner tool40in place. In order to unlock or release inner tool40, the physician may apply counter-clockwise rotational pressure to outer cam lock72to rotate inner cam lock ring70, enabling the material of valve28to naturally expand back to an expanded configuration.

FIGS.7A and7Bare perspective views illustrating examples of inner tools40that may be utilized with a delivery catheter configured according to the techniques of this disclosure. In particular,FIG.7Aillustrates an example configuration of a mechanical tether200that may be configured to implant an IMD210within a vasculature of a patient.FIG.7Billustrates an example configuration of a snare220that may be configured to retrieve IMD210from within a vasculature of a patient. Both mechanical tether200and snare220may be configured to be received within and slidably extend through the various lumen of delivery catheter48described herein, and be engaged by clamping assembly38of the delivery catheter, as described herein with respect to inner tool40(FIG.1).

As illustrated inFIG.7A, mechanical tether200may include an elongated shaft206, a handle202at a proximal end of elongated shaft206, and a tether head assembly204at a distal end of elongated shaft206. Elongated shaft206may be of sufficient length that a clinician may manipulate handle202to advance tether head assembly204out of distal opening of a device cup18of delivery catheter48. Handle202may include buttons, sliders, or other actuatable elements to allow a clinician to manipulate mechanical tether200, e.g., deflect or otherwise steer elongated shaft206, and/or selectively connect and disconnect tether head assembly204from IMD210.

In the example ofFIG.7A, a proximal end of IMD210includes an attachment member212comprising an inner attachment element214and a neck portion216. Tether head assembly204may have one or more features that are actuatable via handle202and configured to selectively receive, retain, grasp, capture, or otherwise connect to attachment member212, e.g., to inner attachment element214or neck portion216. Example configurations of mechanical tethers and attachment members of IMD, and techniques for using the same, are described in commonly-assigned U.S. Provisional Patent Application No. 62/844,674, filed on May 7, 2019, and incorporated herein by reference in its entirety.

As illustrated inFIG.7B, snare220may include an elongated shaft226, a handle222at a proximal end of elongated shaft226, and a snare assembly224at a distal end of elongated shaft226. Elongated shaft226may be of sufficient length that a clinician may manipulate handle222to advance snare assembly224out of a distal end of delivery catheter48. Handle222may include buttons, sliders, or other actuatable elements to allow a clinician to manipulate snare220, e.g., deflect or otherwise steer elongated shaft226, and/or selectively advance, retract, or steer snare assembly224to retrieve IMD210. Snare assembly224may be slidably engaged within elongated shaft226to expand (e.g., open) and contract (e.g., close) one or more loop thereof. In some examples, snare assembly224may include one or more loops, e.g., metal wire loops. In other examples, snare assembly224may additionally or alternatively include one or more nets or stent-like elements configured to expand or contract. In these and other examples, snare assembly224may include elements configured to extend over attachment member212, and then be actuated to a reduced sized configured to capture attachment member212, e.g., to grasp attachment member at neck portion216. Example configurations of snares and attachment members of IMD, and techniques for using the same, are described in commonly-assigned U.S. Provisional Patent Application No. 62/743,939, filed on Oct. 10, 2018, and incorporated herein by reference in its entirety.

FIG.8is a flow chart illustrating a method of delivering an IMD within a vasculature of a patient, in accordance with some techniques of this disclosure. The method ofFIG.5is described with respect to the system and components ofFIG.1, but may be performed with other similar systems and components. A physician or other qualified user or operator may radially compress clamp button26on handle14at a proximal end of an IMD delivery catheter48to engage clamping assembly38(130). Radially compressing clamp button26causes a set of button teeth22to engage with a set of body teeth24, retaining clamp button26in a locked position. In this locked position, a spade36engages with an outer surface of clamp tube60, deforming clamp tube60and collapsing its inner lumen around an elongated inner tool40passing through the lumen. Additionally, a portion of the outer surface of clamp tube60that is opposite spade36may wedge into pinch window34, further deforming the interior lumen of clamp tube60against the inner tool, retaining the inner tool firmly in place. In some examples, inner tool40may include an elongated tether configured to deliver IMD to an implant site within the vasculature of a patient. In other examples, inner tool40may include a snare configured to retrieve IMD from within the vasculature of a patient.

Once inner tool40is locked in place by clamping assembly38, the physician may distally insert and advance delivery catheter48through the lumen of an introducer or outer member16toward a tissue implant site within the vasculature of the patient (132). In some examples, the physician may manipulate an element, such as tip button52on handle14, to bend or curve the distal end of delivery catheter48to navigate beyond the distal end of introducer16.

Once the distal end of delivery catheter48has approached a tissue implant site, the physician may distally press clamp button26to unclamp clamp tube60from around inner tool40to disengage clamping assembly38(134). Distally pressing clamp button26causes button teeth22to disengage from body teeth24, and the expansion of clamp tube60will force clamp button26radially to its original “unlocked” position.

Once inner tool40has been unclamped from clamp tube60, the physician may actuate inner tool40, e.g., distally advance inner tool40out of device cup18, or otherwise move inner tool40through valve lumen62and other lumen of delivery catheter48described herein, to implant engage one or more fixation members of the IMD into tissue the tissue implant site (136). The physician may then further actuate inner tool50by activating a mechanism, such as a button or switch, on the proximal end of inner tool40to release the IMD from the distal end of inner tool40(138). In some examples, but not all examples, the physician may then radially compress button26to once again pinch clamp tube60around inner tool40(140). Finally, the physician may proximally withdraw delivery catheter48through outer member16(142).

In some examples, the physician may partially depress button26to apply a holding force to tool40, without completely clamping valve28shut. For example, the physician may use the partially depressed button26to apply resistance to tool40to generally hold it in position, yet still allow tool40to be moved if needed by applying more force to the tool. This may enable the physician to implant or retrieve an IMD without requiring an assistant to operate either handle14or tool40. This could be especially useful when utilizing tool40as a snare to retrieve the IMD210.

The following clauses provide some examples of the disclosure.

Clause 1: In some examples, an implantable medical device delivery catheter includes: a shaft configured to extend through a vasculature of a patient, wherein the shaft comprises a shaft lumen extending from a proximal end of the shaft to a distal end of the shaft; and a handle connected to the proximal end of the shaft, the handle comprising: an elongated member disposed within the handle, the elongated member comprising an elongated member lumen in fluid communication with the shaft lumen, wherein the elongated member lumen and the shaft lumen are configured to receive an inner tool configured to extend through the elongated member lumen and the shaft lumen and interface with the implantable medical device; and a clamping assembly including a button configured to be actuated toward a longitudinal axis of the elongated member in a direction transverse to the longitudinal axis to compress the elongated member against the inner tool to restrain movement of the inner tool through the elongated member lumen.

Clause 2: In some examples of the delivery catheter of clause 1, the button is configured to be actuated from a first position to a second position in which the button compresses the elongated member against the inner tool.

Clause 3: In some examples of the delivery catheter of clause 2, the clamping assembly includes a set of distal-facing teeth and the button includes a set of proximal-facing teeth configured to engage with the set of distal-facing teeth and hold the button in the second position.

Clause 4: In some examples of the delivery catheter of clause 2, the button is further configured to be actuated from the second position to the first position in response to a longitudinal force in a direction of the distal end of the catheter.

Clause 5: In some examples of the delivery catheter of any of clauses 2 to 4, the button further includes a spade configured to engage with an outer surface of the elongated member.

Clause 6: In some examples of the delivery catheter of any of clauses 1 to 5, the elongated member includes a flexible polymer.

Clause 7: In some examples of the delivery catheter of clause 6, the flexible polymer comprises rubber.

Clause 8: In some examples of the delivery catheter of any of clauses 1 to 7, the clamping assembly includes a valve cap.

Clause 9: In some examples of the delivery catheter of clause 8, the valve cap includes a semi-cylindrical member configured to support an underside of the elongated member.

Clause 10: In some examples of the delivery catheter of clause 9, the semi-cylindrical member defines a pinch window configured to receive a portion of the elongated member to distort the lumen of the elongated member when the clamping assembly is engaged with the elongated member.

Clause 11: In some examples of the delivery catheter of clause 9 or clause 10, the clamping assembly is configured to compress the elongated member between a button and the semi-cylindrical member, the button configured to be actuated toward a longitudinal axis of the elongate member in a direction transverse to the longitudinal axis of the elongate member.

Clause 12: In some examples of the delivery catheter of clause 8, the valve cap further includes a locking mechanism configured to secure the valve cap to the elongated member.

Clause 13: In some examples of the delivery catheter of any of clauses 1 to 12, the clamping assembly is disposed at a proximal end of the handle.

Clause 14: In some examples, a method includes: engaging a clamping assembly of a handle of a medical device delivery catheter for a first time to restrain movement of an inner tool through an elongated member lumen of an elongated member disposed within the handle, wherein engaging the clamping assembly includes actuating a button of the clamping assembly toward a longitudinal axis of the elongate member in a direction transverse to the longitudinal axis to compress the elongated member against the inner tool; with the clamping assembly engaged for the first time, introducing a distal end of a shaft of the delivery catheter into a vasculature of a patient toward a tissue site, wherein the shaft includes a shaft lumen extending from a proximal end of the shaft to a distal end of the shaft, wherein the handle is connected to the proximal end of the shaft, wherein the shaft lumen is in fluid communication with the elongated member lumen, wherein the shaft lumen and the elongated member lumen are configured to receive the inner tool, and wherein the inner tool is configured to interface with an implantable medical device; releasing the clamping assembly, wherein releasing the clamping assembly includes actuating the button of the clamping assembly away from the longitudinal axis of the elongate member; with the clamping assembly released, actuating the inner tool, wherein actuating the inner tool includes moving the inner tool through the shaft lumen and the elongated member lumen; after actuating the inner tool, engaging the clamping assembly a second time to restrain movement of the inner tool through the elongated member lumen; and with the clamping assembly engaged the second time, proximally withdrawing the shaft from the patient.

Clause 15: In some examples of the method of clause 14, engaging the clamping assembly includes actuating the button from a first position to a second position in which the button compresses the elongated member against the inner tool.

Clause 16: In some examples of the method of clause 15, the clamping assembly locks the button in the second position, and releasing the clamping assembly includes unlocking the clamping assembly.

Clause 17: In some examples of the method of clause 15, engaging the clamping assembly includes manually holding the clamping assembly in the second position.

Clause 18: In some examples of the method of any of clauses 14 to 17, the inner tool is a mechanical tether, and actuating the inner tool includes releasing the implantable medical device from the tether.

Clause 19: In some examples of the method of any of clauses 14 to 17, the inner tool is a snare, and actuating the inner tool includes grabbing the implantable medical device with a distal end of the snare.

Clause 20: In some examples, a system includes the delivery catheter of clause 1 and an inner tool.

Clause 21: In some examples of the system of clause 20, the inner tool includes a mechanical tether configured to implant an IMD within a vasculature of a patient.

Clause 22: In some examples of the system of clause 20, the inner tool includes a snare configured to retrieve an IMD from within a vasculature of a patient.

Clause 23: In some examples of the system of any of clauses 20 to 22, the system further includes the implantable medical device, wherein the implantable medical device includes a pacemaker.