WO2020068664A1

WO2020068664A1 - Devices and techniques for endoscopic intracardiac suture placement

Info

Publication number: WO2020068664A1
Application number: PCT/US2019/052421
Authority: WO
Inventors: Albert K. Chin; Murali Dharan; Jeffry J. Grainger
Original assignee: Mitrx, Inc.
Priority date: 2018-09-24
Filing date: 2019-09-23
Publication date: 2020-04-02

Abstract

Intracardiac instruments, systems, and methods of using intracardiac instruments. An instrument comprises an instrument body, an interventional device, and a translucent viewing tip are provided. The instrument body has a proximal portion, a distal portion, a viewing lumen, and an instrument lumen, the viewing lumen having a viewing port in the distal portion and the instrument lumen having an exit port in the distal portion. The interventional device is device positionable in the instrument lumen and extendable from the exit port. The a translucent viewing tip is sealingly coupled to the distal portion over the viewing port and has an outer surface configured to engage cardiac tissue, the exit port being outside the viewing tip. When positioned in a blood-filled space, the viewing tip is configured to displace blood away from the viewing port to allow visualization of the cardiac tissue and the interventional device through the viewing lumen.

Description

DEVICES AND TECHNIQUES FOR ENDOSCOPIC INTRACARDIAC SUTURE

PLACEMENT

CROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application No. 62/735,595, filed September 24, 2018, which application is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

[0002] Field of the Invention. This relates generally to devices and techniques for applying sutures inside the chambers of a beating heart under direct endoscopic visualization. The devices allow a surgeon to view intracardiac structures in a blood-filled heart, and to perform heart surgery under continuous visual guidance.

[0003] Surgical procedures that require suture placement inside the heart typically require the patient to be placed on cardiopulmonary bypass, stopping the heart, performing a surgical incision on the heart wall to provide access to the chambers such as the atria or ventricles, and providing a bloodless surgical field inside the heart as the patient’s circulation is supported by an external pump. Open heart surgery is invasive and painful postoperatively, as it generally requires a sternotomy, with cutting the sternal bone; or a thoracotomy, involving a large incision between the ribs, with significant displacement or retraction of the ribs.

SUMMARY OF THE INVENTION

[0004] Devices and techniques are desired whereby a surgeon may be able to enter the inner chamber of a beating heart and place intracardiac sutures or perform other surgical manipulations under direct visual guidance. The endoscopic intracardiac surgical device enters the heart through an incision in the heart wall that is encircled by a purse string-type suture, to seal around the device and prevent blood loss during the procedure. A valved port may also provide intracardiac access, with the port placed through the heart incision and secured in position via a purse string suture. Use of a valved port allows multiple insertions and removal of a surgical device without the need to tighten and loosen the purse string suture with every device removal or exchange.

[0005] The endoscopic intracardiac surgical device consists of a cannula that contains multiple channels. One channel comprises a visualization channel configured to receive an endoscope, or otherwise configured to allow visualization therethrough. The distal end of the visualization channel is enclosed with a transparent viewing tip. The viewing tip may be a conical, spherical, bullet-shaped, ovoid, bulbous, or elongated in shape. In preferred embodiments the viewing tip is inflatable, constructed of a membrane of flexible, inelastic material such as PET (polyethylene terephthalate) or PVC (polyvinyl chloride), defining a hollow inner chamber, and inflated with fluid to achieve its shape. Alternatively the viewing tip may comprise an elastic balloon which can be expanded to the desired diameter either larger or smaller than the cannula diameter. The viewing tip may also be solid through its cross-section and composed of a rigid or semi-rigid transparent material. The viewing tip is optically aligned with or coupled to the endoscope in the visualization channel such that the surgical field may be viewed distal to the viewing tip. Following insertion into a beating heart, the viewing tip may be placed against structures inside the heart. Blood is displaced from cardiac structures that are in contact with the surface of the tip, providing a clear, bloodless view of the desired structure.

[0006] The intracardiac surgical device may include an end effector for performing a function on intracardiac tissue within a blood-filled field. In some embodiments, surgical instruments may be housed in one or more instrument channels within the cannula. These instruments may be retracted into the inside of the cannula during cannula insertion into the heart, to prevent the instruments from snagging on intracardiac structures such as valve leaflets. The instruments may be extended when the cannula tip has been advanced to the desired position within the cardiac chambers. In some embodiments the viewing tip is positioned adjacent and distal to the distal end of the instrument channel(s) such that structures to be manipulated with such instruments can be viewed as they are manipulated. Preferably the viewing tip is configured to allow an instrument to be advanced into engagement with tissue while maintaining contact between the viewing tip and the tissue. To facilitate this, the viewing tip may be deformable or deflectable relative to the remainder of the cannula. For example, a fluid-inflated viewing tip may be used which is sufficiently flexible and/or compressible to allow displacement of fluid inside the viewing tip as the instrument is extended into position. This allows the viewing tip to conform to the tissue structure and/or surgical instrument so as to maintain contact therewith. The pressure of the fluid within the viewing tip may also be adjusted to alter it rigidity and deformability.

[0007] In other embodiments the instrument channel extends through the viewing tip such that the viewing tip is disposed circumferentially around the distal opening of the instrument channel. In such embodiments the cannula may have one or more instrument channels running in parallel with the visualization channel. A portion of the cannula containing the instrument channel may extend a short distance beyond the distal end of the visualization channel. A distal portion of the viewing tip may be attached to the cannula around the periphery of the instrument channel, while a proximal portion of the viewing tip is attached to the cannula around the periphery of the visualization channel. Preferably the viewing tip comprises an elastic balloon which may be expanded to a diameter larger than the cannula diameter. In this way, an instrument may be inserted through the instrument channel and the distal tip and target tissue may be visualized through the viewing tip. The viewing tip may further be used to engage and displace tissue which is to be sutured or manipulated by the instrument.

[0008] In one embodiment the intracardiac surgical device includes a surgical device slidably received within an instrument channel in the cannula. The surgical device may include a tapered needle containing a slot in its distal tip and an elongated needle shaft extending proximally therefrom. Residing in the slot is a suture strand containing an anchoring member of larger cross-section, which may be a single simple knot in the suture or a separate structure attached to the suture, near its distal end. The surgical device further includes a target, which may comprise an elongated target shaft and a rigid frame at the distal end of the target shaft defining an opening. The frame holds an elastic membrane in tension across the opening. The tapered needle is longitudinally movable relative to the target, and the sharp distal tip is aligned with the membrane on a proximal side thereof.

[0009] In use, the target is positioned such that a proximal face of the elastic membrane is placed against the intracardiac tissue on the side opposite the needle entry site. With the viewing tip engaging the near side of the intracardiac tissue, the needle may be advanced relative to the tissue and the target so that the needle tip is first inserted through tissue, then through the face of the membrane on the opposite side of the tissue. The rigid frame and membrane act as a backstop to limit displacement of the tissue as the needle passes through it. The anchoring member in the suture is carried by the needle through the elastic membrane in the center of the rigid frame. The needle may then be retracted relative to the target, and the anchoring member remains trapped by the elastic membrane as the needle is withdrawn from the tissue. The target and needle may then be withdrawn, either by themselves or together with the cannula, out of the patient’s body, drawing the suture through the target tissue. The two ends of the suture, now disposed outside the patient’s body, may be placed in a suture holder near the patient’s skin surface. The suture holder may be attached to the proximal end of the cannula, or attached to a trocar port or other device used for cardiac entry. The suture holder may comprise a disc composed of elastic material with multiple closed slots formed around its circumference. The two free ends of a suture may slide into a single slot, and be retained by the compressive force exerted by the sides of the slot. Multiple paired suture ends may be inserted into individual slots and be organized for subsequent insertion in an annuloplasty band or ring or other implantable device.

[0010] The needle used for suture placement may be oriented axially with respect to the cannula, either as a straight needle or a needle with a slight curvature along its axis. In other embodiments, the needle may be a curved needle with approximately a 1-2 cm radius of curvature, mounted such that the axis of curvature of the needle is parallel to the longitudinal axis of the cannula. The curved needle is attached to a stem that extends the length of an axially oriented channel inside the cannula. Rotation of the stem at the proximal end of the device about its longitudinal axis rotates the curved needle through tissue for suture placement. An orthogonally mounted, curved needle may be used to sew in tissue surfaces which are more aligned with the longitudinal axis of the cannula; for example, in the mitral valve annulus. In contrast, an axially oriented straight needle may be used to sew in transversely oriented tissue surfaces; for example, a mitral valve leaflet, or the atrial-facing surface of the mitral annulus. In still other embodiments, a curved needle may be mounted such that its axis of curvature is transverse to the longitudinal axis of the cannula, and a pinion gear or other suitable mechanism may be used to rotationally drive the needle about its axis of curvature. Such a configuration may be useful for passing a suture into and out of a tissue surface which is transverse to the longitudinal axis of the cannula.

[0011] Another embodiment of a surgical device is configured to apply a spiral tack with an attached suture strand that is implanted into an intracardiac structure such as the mitral annulus in the left atrium or the papillary muscle in the left ventricle. A tubular tack delivery device may be advanced through an instrument channel in the endoscopic cannula. In embodiments in which the viewing tip is adjacent to the instrument channel, the delivery device may engage and displace the wall of the inflatable viewing tip as it proceeds to the site of tissue insertion. The tack delivery device releasably holds a spiral tack at its distal end.

The middle section of a suture, or the ends of two or more separate sutures, may be attached to the spiral tack, with the suture extremities extending proximally through the tubular delivery device. The tack delivery device drives the tack rotationally and distally into the intracardiac tissue. Following rotational deployment of the tack into intracardiac tissue, the two ends of the attached suture are withdrawn from the patient’s body, and placed in a suture holder near the skin access incision. [0012] Endoscopic suture placement into intracardiac tissue enables cardiac surgical procedures to be performed without a large incision, and without the need to cut the sternal bone with a sternotomy. Specifically, for mitral valve repair procedures, mitral annuloplasty and repair of ruptured chordae tendineae may be performed with endoscopic surgical devices. Mitral annuloplasty may be performed to correct a dilated or a normal sized annulus when used to augment mitral valvular repair. . Endoscopic mitral annuloplasty may be performed by placing multiple spaced suture strands in the mitral annulus. The endoscopic suture placement instrument places individual suture strands into the mitral annulus. Following the placement of each suture strand, the device is removed from the patient’s body, and the multiple suture strands may be inserted into a slotted suture organizer on the trocar access port. The suture organizer may be a flexible or elastomeric flange that contains multiple slots that pinch and hold inserted suture strands. The proximal suture strands are inserted into an annuloplasty band or annuloplasty ring outside the patient’s body, and subsequently the band or ring is advanced down the sutures into position on the mitral annulus, using an instrument such as an endoscopic grasper or a positioner. The spacing between the sutures on the annuloplasty band or ring is preferably less than the spacing between the sutures placed on the mitral annulus. Therefore, upon ligation of the suture strands, the mitral annulus is cinched together to decrease its diameter and correct the valvular regurgitation. The annuloplasty bands or rings may be constructed of polymeric material, polymeric fabric, metal such as stainless steel or Nitinol; or a composite of polymeric material, polymeric fabric and/or metal. Ideally, they are sufficiently elastic, collapsible, or deformable to allow delivery through an access port that has approximately 10 mm to 15 mm inner diameter.

[0013] Chordae tendineae extend from the papillary muscles at the apex of the left ventricle to the free edges of the mitral valve. Rupture of one or more chordae tendineae changes the geometry of the mitral valve leaflet and causes valvular incompetence. To repair ruptured chordae tendineae , one or more suture strands may be placed in the papillary muscle corresponding to the ruptured chords, and multiple suture strands may be placed in the edge of the mitral valve leaflet at the sites of ruptured chordal attachment. The proximal ends of all suture strands are withdrawn from the body and placed on an external suture holder. In one embodiment, the proximal ends of the respective sutures may be passed through the corners of a common attachment element outside the patient’s body. The common attachment element may be triangular in shape and composed of a polymeric fabric such as polytetrafluoroethylene (PTFE), polypropylene, nylon or similar woven material. Following suture insertion, the attachment element may be advanced into apposition with the papillary muscle, by sliding it along the sutures using an endoscopic grasper or positioner to hold it during insertion. The suture strand in the papillary muscle may be ligated first, either by tying a series of intracorporeal knots, or by using other ligation means such as a surgical suture crimping device to fix the suture relative to the common attachment element. The suture strands placed in the free edge of the mitral valve leaflet are ligated next using knots or crimping devices, after their lengths are adjusted to provide proper coaptation of the valve leaflets. Suture length adjustment may be performed under transesophageal

echocardiographic guidance, with real time evaluation of mitral leaflet coaptation and an absence of valvular regurgitation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. la - lc show the configuration of the endoscopic intracardiac surgical device with an axial needle.

[0015] FIG. 2a - 2c depict deployment of the endoscopic intracardiac suture placement mechanism with an axial needle.

[0016] FIG. 3 a - 3b show the suture loaded needle configuration of the axially oriented endoscopic surgical device.

[0017] FIG. 4a - 4e depict the steps used in applying the axially oriented endoscopic surgical device to a cardiac valve leaflet.

[0018] FIG. 5a - 5c show the configuration of the orthogonally oriented endoscopic surgical device.

[0019] FIG. 6a - 6c depict the steps used in applying the orthogonally oriented endoscopic surgical device.

[0020] FIG. 7a - 7d show the orthogonally oriented endoscopic surgical device as it sutures tissue.

[0021] FIG. 8a - 8b shows the inflatable viewing tip and instrument advancement along the tip.

[0022] FIGS 9A-D show the configuration of a suture placement instrument that places a suture coupled with an implanted spiral fixation component.

[0023] FIG. lOa - lOb shows the spiral fixation suture placement instrument applied with an inflatable viewing tip endoscopic cannula.

[0024] FIG. 11 shows the spiral fixation suture placement instrument applied to the annulus of the mitral valve. [0025] FIG. 12 depicts multiple suture strands applied to the annulus of the mitral valve during placement of an annuloplasty band for mitral valve repair.

[0026] FIGS. 13A-D show an intracardiac cannula according to the invention in a further embodiment thereof.

[0027] FIG. 14 shows insertion of a spiral fixation suture into the papillary muscle for the repair of ruptured chordae tendineae.

[0028] FIG. 15 shows insertion of multiple suture strands into the mitral valve leaflet during the repair of ruptured chordae tendineae.

[0029] FIG. 16 shows the configuration of multiple suture strands in the mitral valve leaflet in addition to a suture strand in the papillary muscle during the repair of ruptured chordae tendineae.

[0030] FIG. 17 depicts the placement of the proximal ends of suture strands through an attachment element during the repair of ruptured chordae tendineae.

[0031] FIGS. l8a - 18b show a flexible flange attached to the trocar port used for cardiac access, and the use of the flange for organization of multiple suture strands.

[0032] FIGS. 19A-D schematically illustrate a rotational needle driver for applying a suture to a mitral annulus or papillary muscle according to the invention.

[0033] FIG 20 schematically illustrates an exemplary drive mechanism for the rotational needle driver of FIGS 19A-D.

DETAILED DESCRIPTION OF THE INVENTION

[0034] In one embodiment of the invention, a cannula is provided to perform endoscopic intracardiac suture placement. The configuration of a cannula that incorporates an axially oriented needle is shown in FIG. la. The cannula 10 has a visualization lumen 12A configured to receive an endoscope 12, and the distal end of the lumen is sealed by a transparent viewing tip 11. The endoscope is also sealed at the proximal end of the cannula, such that no fluid may enter into the lumen occupied by the endoscope 12 and disrupt endoscopic visualization. In preferred embodiments cannula 10 further includes a fluid delivery port (not shown) at its proximal end in fluid communication with lumen 12 A, through which a fluid may be introduced for inflation/expansion of viewing tip 11.

[0035] Cannula 10 also contains instrument channels 13 and 15 configured to slidably receive target 14 and axial needle 16 that retract into cannula 10 and extend out past viewing tip 11 to perform intracardiac surgery. FIG. lb is an end view showing retraction of target 14 into the cannula 10. FIG. lc is an enlarged view of needle 16 showing an axial slot 17 extending across the diameter of the distal tip of needle 16 on the angled face thereof.

[0036] FIG. 2a - 2c depict the mechanics of target 14. FIG. 2a shows the cannula 10 in its initial state, with target 14 retracted into its inner lumen. FIG. 2b is an end view of cannula 10 in its initial state. FIG. 2c shows the target extended forward past viewing tip 11. Target 14 is composed of two spring loaded parts 18, 22 that are axially slidable relative to each other so as to close to exert a compressive force between the parts. A rigid curvilinear frame 18 is attached to a stem 19 that slides within tube 21. A semi-circular wire 22 attached to tube 21 slides relative to frame 18 to engage the proximal surface of curvilinear frame 18. Frame 18 and wire 22 lie in parallel planes transverse to the longitudinal axis of cannula 10. Tissue structures may be grasped and compressed between frame 18 and semi-circular wire 22, as well as manipulated and stabilized. A membrane 20 of elastic polymer, mesh, or other suitable material is stretched across frame 18 and secured thereto.

[0037] FIG. 3 a - 3b depict the configuration of the needle 16 used to perform intracardiac suture placement. The target 14 is seen extended out of cannula 10 in FIG. 3a, while distally slotted needle 16 remains retracted inside cannula 10. FIG. 3b is an enlarged view of needle 16, demonstrating how a suture 24 with an enlarged bulb or knot 25 may reside in slot 17 in the distal tip of needle 16 for subsequent delivery through tissue. Target 14 and needle 16 may be disposed in the same or separate instrument lumens in cannula 10. Frame 18 is axially aligned with needle 16 such that if needle 16 is advanced its distal tip passes through the membrane 20 across the opening defined by frame 18.

[0038] FIG. 4a - 4e demonstrate the series of steps in placing a suture 24 through a heart valve leaflet 23. FIG. 4a shows the frame 18 and semi-circular wire 22 opened and placed on either side of the valve leaflet 23. In FIG. 4b they are closed by moving wire 22 toward frame 18 to grasp valve leaflet 23. Preferably wire 22 is spring loaded so as to automatically advance toward frame 18 when released. FIG. 4c shows needle 16 advanced forward to pierce valve leaflet 23 and the membrane 20 of the target 14. In FIG. 4d, needle 16 is retracted, leaving knot 25 of suture 24 trapped by membrane 20. Upon removal of cannula 10 from the body of the patient, the membrane 20 pulls the knot 25 out of the patient, leaving a loop of suture 24 placed through the valve leaflet 23. Use of the membrane 20 to hold a knot 25 for suture placement is advantageous, as it allows repeated suture placement without the need to individually attach needles to each suture strand, and the membrane permits multiple needle puncture and suture passage without wearing out. [0039] FIG. 5a - 5c illustrate an endoscopic intracardiac surgical device with an orthogonally oriented curved needle that allows suture placement on a side wall of tissue.

FIG. 5a shows a curved needle 26 and target 28 retracted inside cannula 10. Curved needle 26 lies generally in a plane transverse to the longitudinal axis of cannula 10. A control tube 29 lies inside the cannula 10, and it translates axially with respect to cannula 10. The target 28 contains a stem 19 that extends proximally and passes through a sleeve 30 that is attached to the inner wall of the cannula 10. The proximal end of the stem 19 is attached to the proximal portion of control tube 29. The attachment of stem 19 to the control tube 29, and its passage through sleeve 30 that is attached to the inner wall of cannula 10 serves to index the control tube radially with respect to the cannula 10, as it translates proximally and distally during extension and retraction of curved needle 26 and target 28. Curved needle 26 is attached to a long bushing 32 that lies inside control tube 29. A lever 33 attached to the proximal portion of long bushing 32 rotates curved needle 26 with respect to target 28 about an axis of rotation parallel to the longitudinal axis of cannula 10. FIG. 5b shows the initial position of curved needle 26 with respect to target 28 in which the tip of needle 26 is rotationally separated from target 28. FIG. 5c shows an enlarged view of curved needle 26. The side view shows the position of a slot 27 in the distal tip of curved needle 26.

[0040] FIG. 6a - 6c depict the actuation of the curved needle endoscopic intracardiac surgical device. FIG. 6a shows the device in its initial position. FIG. 6b depicts distal extension of the curved needle 26 and target 28 by forward translation of control tube 29, such that needle 26 and target 28 are positioned adjacent to viewing tip 11. FIG. 6c shows rotation of curved needle 26 to intersect target 28 by clockwise movement of lever 33.

[0041] FIG. 7a - 7d depict the placement of a suture into tissue using the curved needle endoscopic intracardiac surgical device. FIG. 7a shows placement of cannula 10 against the side wall of intracardiac tissue 34, with suture 24 loaded inside the device. FIG. 7b shows distal extension of the curved needle 26 and target 28 by forward translation of control tube 29. The curved needle 26 lies against the surface of intracardiac tissue 34 on the right side of viewing tip 11, and the target 28 lies against the surface of intracardiac tissue 34 on the left side of viewing tip 11. FIG. 7c shows rotation of curved needle 26 through intracardiac tissue 34, then through the face of target 28 by clockwise movement of lever 33. FIG. 7d shows completion of suture placement with counterclockwise movement of lever 33 to withdraw the curved needle 26 from intracardiac tissue 34, and removal of cannula 10 from the patient’s body, with the target 28 pulling the knotted end of suture 24 out with the cannula 10. This leaves a loop of suture through target tissue 34. [0042] FIG. 8a - 8b demonstrate the mechanism of maintaining endoscopic visualization using an inflatable viewing tip 35. FIG. 8a shows the surface of inflatable viewing tip 35 making contact with the surface of intracardiac tissue 34. This surface contact displaces blood in the region between the tip of endoscope 12 and intracardiac tissue 34 to provide clear endoscopic visualization thereof. FIG. 8b shows a surgical instrument 36 advancing out of cannula 10. The inflatable viewing tip 35 is sufficiently flexible and/or compressible to conform to the surgical instrument 36 as it is advanced, providing clear visualization of the surgical instrument and allowing surgical instrument 36 to advance distally without lifting the contact surface of viewing tip 35 from the surface of intracardiac tissue 34.

[0043] FIGS. 9a- 9b shows an alternate instrument 36 that places an intracardiac suture 24 attached to an implantable spiral 37 for anchoring a suture in tissue. The spiral anchor placement instrument 36 has a elongated tubular shaft 36A and may utilize one or more rigid posts 39 extending from a distal end of shaft 36A to stabilize the spiral 37 for its rotation into tissue. An elastic sleeve 40 may encircle the spiral on the distal end of instrument 36, covering the spiral during its advancement into position to prevent injury to the inflatable viewing tip or adjacent cardiac tissue, while deforming upon spiral rotation into tissue so it does not impede insertion. The two ends of suture 24 extend proximally from spiral 37 through the tubular shaft to a location outside the body. It will be understood that while a single suture is shown fixed in a mid-portion to the spiral 37, a single suture may be fixed at one end to spiral 37 such that only a single end extends from the spiral, or multiple sutures may be fixed to a single spiral 37. The suture may be attached to spiral 37 simply by a loop or knot, or by bonding, fusing, or crimping. Further, spiral 37 may include an eyelet or other suitable structure to facilitate fastening the suture thereto.

[0044] FIGS 9C-9D illustrate a further embodiment of spiral anchor placement instrument 36. In this embodiment spiral 37 is held in place during implantation by suture 24 which is held in tension at the proximal end of the instrument. In the configuration shown, instrument 36 includes a tubular handle 140 at its proximal end and a cap 142 inserted into the end of handle 140. Cap 142 has an axial bore 144 and elastomeric wall 146 closing off bore 144 at its proximal end. Elastomeric wall 146 has a slit 148 therein, one end of which is optionally widened to create a gap 150, shown in the end view of FIG 9D. Suture 24 extends proximally from coil 37 through handle 140 and exits the instrument through bore 144 and slit 148. The opposing edges of wall 146 along slit 148 are configured to engage suture 24 to hold it in tension with sufficient force that spiral 37 remains secure at the distal tip of the instrument as it is driven into tissue. When spiral 37 has been implanted, suture 24 may be released by sliding it along slit 148 into gap 150. While a single suture 24 is shown in FIGS 9C-D, it will be understood that two or more strands of suture may be coupled to spiral 37 and held in tension in the same way. Further, instead of frictionally retaining the sutures in slit 148 as in FIGS 9C-D, the sutures may be held in tension by other means, including by coupling to a cleat or clip on the proximal end of instrument 36, by clamping with a set screw-like mechanism, or by other means.

[0045] FIG. lOa - lOb demonstrate the spiral fixation suture placement instrument 36 used with the inflatable viewing tip 35 on the distal end of cannula 10. FIG. lOa shows suture placement instrument 36 slidably disposed in an instrument lumen within cannula 10, with distal end retracted into the cannula 10. FIG. lOb shows the suture placement instrument 36 advanced distally from cannula 10 and displacing or deforming inflatable viewing tip 35 laterally as it makes contact with the surface of intracardiac tissue 34.

[0046] FIG. 11 shows the spiral fixation suture placement instrument 36 inserted into the left atrium 41 of the heart and placed in contact with the mitral annulus 41, during insertion of the spiral 37. For purposes of clarity, cannula 10 is not shown, however, in actual use the spiral fixation suture placement instrument 36 would be placed through an instrument channel of cannula 10 as shown in Figs. lOa-b. Viewing tip 35 would be inflated and positioned so as to engage the mitral annulus 42, providing visualization as the instrument 36 is used to implant each spiral 37. Optionally, spiral 37 may have a barbed tip, or include one or more one-way barbs, scales, fins or arrowheads along the sidewalls of the coil to retain it in the heart tissue and prevent it from backing out of the tissue over time.

[0047] FIG. 12 depicts the placement of multiple strands of suture 24 attached to spirals 37 inserted into mitral annulus 41 in a spaced configuration. Following placement, a proximal end of each suture strand 24 is inserted through an annulopasty band or ring (not shown) outside the chest cavity. The distance between suture strands 24 in the band or ring is preferably less than the distance between spirals 37 in mitral annulus 41. Upon advancement of the band or ring down suture strands 24 into contact with mitral annulus 41, and subsequent cinching of each suture strand 24, the circumference of mitral annulus 41 is decreased. Suture strands 24 may then be secured by knotting, crimping or other suitable method. This technique of mitral valve repair is used to address mitral valve regurgitation due to a dilated mitral annulus, leading to loss of apposition and incompetence of the mitral valve leaflets 45.

[0048] FIGS. 13A-D illustrate a further embodiment of an intracardiac cannula 60 according to the invention. In this embodiment cannula 60 has a shaft 62 having multiple lumens including a viewing lumen 64, an instrument lumen 66, and an inflation lumen 68. In one embodiment, shown in Fig. 13B-1, intracardiac cannula 60 comprises a solid multi- lumen shaft 62, which may be a unitary extrusion of a suitable polymer. In an alternative embodiment, shown in Fig. 13B-2, shaft 62 comprises an outer tube 63 having an inner lumen 65, in which are disposed a first inner tube 69 forming viewing lumen 64 and a second inner tube 71 forming instrument lumen 66. Inner lumen 65 may be used as an inflation lumen.

[0049] Viewing lumen 64 is configured to receive an endoscope 68, and instrument lumen is configured to slidably receive an endoscopic instrument 70, which may comprise any of the suturing instruments disclosed herein, or any other suitable instrument. A tubular tip extension 74 is mounted to the distal end 76 of shaft 62 axially aligned with instrument lumen 66. A balloon 78 has a proximal end 80 sealingly fixed around the circumference of shaft 62, and a distal end 82 sealingly fixed around the circumference of tip extension 74. Inflation lumen has a distal opening in communication with the interior of balloon 78 and is in communication with an inflation port 84 mounted near the proximal end of shaft 62. Balloon 78 is preferably a translucent, elastic distensible material such that when it is engaged by tissue it will move and conform to such tissue. Further, if balloon 78 is displaced such that it engages instrument 70 it will preferably conform to the instrument rather than inhibiting its motion or deflecting it from the target tissue.

[0050] It may be seen that inflation fluid may be delivered through inflation lumen 68 to inflate balloon 78 to the configuration shown in FIG. 13C, in which the diameter of balloon 68 is larger than the diameter of shaft 62, and a distal portion 86 of the inflated balloon extends beyond the distal end of tip extension 74, creating a recess 88 encompassing the distal opening 90 in tip extension 74. This permits the balloon to engage the target tissue, displace blood away from such tissue and allow visualization of instrument 70 within recess 88 using endoscope 68.

[0051] In alternative embodiments, shaft 62 may further include a fluid delivery lumen (not shown) extending through tip extension 74 with a distal opening communicating with recess 88 outside the balloon. This may be used to inject saline or other suitable fluids to further displace blood and create a clear field to visualize the target tissue and instrument 70.

[0052] FIG. 13D illustrates the intracardiac cannula 60 in use at a mitral valve MV within the heart in an exemplary annuloplasty procedure. It may be seen that balloon 78 can be inflated and positioned in engagement with the mitral annulus with recess 88 positioned over the fibrous target tissue. An intracardiac suturing instrument 36 carrying a spiral suture anchor 37, described elsewhere herein, may be inserted through instrument lumen 66 and used to drive spiral 37 into the annulus tissue under visualization through balloon 78 using endoscope 68. Balloon 78 displaces blood away from the tissue and instrument to facilitate visualization.

[0053] FIG. 14 depicts the placement of a spiral 37 containing an attached suture 24 into a papillary muscle 47 inside the heart. The mitral valve leaflet 45 has attachments called chordae tendineae 44 that insert into papillary muscle 47. Intact chordae tendineae 44 may rupture, and ruptured chordae tendineae 45 may be replaced using suture 24 inserted into papillary muscle 47 and attached to the free edge of mitral valve leaflet 45. As in FIG. 12, for purposes of clarity cannula 10 is not shown, however in actual use instrument 36 would be placed through an instrument channel in cannula 10 as shown in FIGS. lOa-b. Viewing tip 35 would be inflated and positioned to engage the papillary muscle adjacent the site where spiral 37 is to be implanted. In this way the surgeon may view the tissue and the insertion of spiral 37 even in a blood-filled field.

[0054] FIG. 15 shows placement of suture strand 24 through the free edge of mitral valve leaflet 45 to replace a ruptured chordae tendineae 46 at its previous site of insertion in the leaflet 45. The suture strand 24 may be looped through the leaflet 45 and adjusted until the leaflet is closing as desired and regurgitation is eliminated, as viewed using transesophageal echocardiography (TEE). Suture 24 may then be tied off and trimmed. In this way a single suture may be used to replace a ruptured chordae tendineae 46.

[0055] FIG. 16 shows placement of a single spiral 37 with multiple attached sutures 24 into a papillary muscle 47 and placement of multiple sutures 24 through mitral valve leaflet 45. The proximal ends of all suture strands 24 are pulled out of the patient’s body in preparation for their attachment to a common attachment element to complete the repair of ruptured chordae tendineae 46.

[0056] FIG. 17 shows the insertion of the proximal ends of suture strands 24 into a triangular shaped common attachment element 48. The common attachment element 48 may be composed of a fabric woven from polymeric threads of materials such as

polytetrafluoroethylene (PTFE), polypropylene, polyester or similar material. Suture strands 24 are passed through common attachment element 48 outside the chest cavity. The common attachment element is then advanced into the heart by sliding down suture stands 24 into proximity with papillary muscle 47. Suture strands 24 are then tensioned the desired amount in order to restore proper valve function and eliminate regurgitation, as viewed using TEE. Suture strands 24 are then tied, fused or otherwise fixed to restore mitral valve leaflet 45 to its correct physiological configuration.

[0057] FIG. 18 shows a flange 53 placed on trocar port 50 used to gain entry into the left atrium of the heart via neck incision 49. Flange 53 may be elastic, inelastic or partially elastic, and it may contain slits 54 that pinch suture strands 24 placed inside them. Multiple slits 54 accommodate and organize individual suture strands 24 during the mitral valve repair procedure.

[0058] FIGS. 19A-D illustrate a further embodiment of a suturing device 100 which may be used with the intracardiac cannula of the invention described elsewhere herein. In this embodiment, suturing device 100 comprises a shaft 102 and a rotational driver 104 rotatably coupled thereto. A needle holder 106 is attached to driver 104 so as to move therewith.

Needle holder 106 is configured to releasably hold a curved needle 108 such that the axis of curvature of needle 106 is disposed transverse to, preferably orthogonal to, a longitudinal axis of shaft 102, and collinear with the axis of rotation of driver 104. In this way, driver 102 drives needle 108 rotationally about a transverse axis of shaft 102. A strand of suture 109 is attached to needle 108 and extends proximally through a port 111 and lumen (not shown) in shaft 102. It may be seen in FIGS 19A-B that suturing device 100 may be oriented such that shaft 102 is generally perpendicular to a tissue surface T and needle 108 may be driven so as to penetrate through surface T, pass through the tissue, and re-emerge from the tissue surface a short distance away.

[0059] In an exemplary embodiment suturing device 100 further includes a retriever 112 for retrieving needle 108, as shown in FIG 19B. In one embodiment retriever 112 comprises a shaft 114 and a needle retainer or target 116 at the distal end of shaft 114. In one

embodiment needle retainer 116 may be a block of foam, sponge, or mesh configured to allow needle 108 to penetrate it and to be retained therein. As shown in FIGS 19C-D needle holder 106 may include a curved tubular sheath 118, in which needle 108 is releasably held, with suture 109 extending slidably through the sheath. Needle 108 may have a tip portion 120 with an arrowhead or barbed configuration to engage needle retainer 116 and inhibit removal therefrom. In this way, when needle 108 is driven into retainer 116 it is caught therein and retriever 112 may be retracted to extract needle 108 from sheath 118 and draw it out of the body, as shown in FIG 19D.

[0060] FIG 20 illustrates a mechanism for rotationally driving a curved needle about a transverse axis which may used in the embodiment of FIGS 19A-D. It will be understood that various types of mechanisms are possible and the embodiment shown is merely exemplary. In this embodiment, driver 104 comprises a first pulley 122 rotatably mounted to shaft 102. Needle holder 106 is attached to first pulley 122 to rotate therewith. A pinion gear 124 is rotatably mounted to shaft 102 and is spaced proximally from first pulley 122. A second pulley 126 is mounted to pinion gear 124 to rotate therewith. A belt 128 extends around first pulley 122 and second pulley 126. Pinion gear 124 is rotated by means of a rack member 130 which is slidable axially within shaft 102. Rack member 130 has a plurality of linearly arranged teeth 132 which mesh with the teeth 134 on pinion gear 124, such that linear motion of rack member 130 rotates pinion gear 124. This moves belt 128, thereby rotating first pulley 122 and driving needle 108 through a curved path.

Claims

WHAT IS CLAIMED IS:

1. An intracardiac instrument comprising:

a instrument body having a proximal portion, a distal portion, a viewing lumen, and an instrument lumen, the viewing lumen having a viewing port in the distal portion and the instrument lumen having an exit port in the distal portion;

an interventional device positionable in the instrument lumen and extendable from the exit port; and

a translucent viewing tip sealingly coupled to the distal portion over the viewing port and having an outer surface configured to engage cardiac tissue, the exit port being outside the viewing tip;

wherein when positioned in a blood-filled space the viewing tip is configured to displace blood away from the viewing port to allow visualization of the cardiac tissue and the interventional device through the viewing lumen.

2. The intracardiac instrument of claim 1 wherein the exit port is distal to the viewing port.

3. The intracardiac instrument of claim 1 wherein the instrument body comprises a shaft having two parallel lumens, a first of the lumens being the viewing lumen and a second of the lumens being the instrument lumen.

4. The intracardiac instrument of claim 1 wherein the instrument body comprises a first tubular shaft containing the viewing lumen, a second tubular shaft containing the instrument lumen, and a third tubular shaft having a third lumen, the first and second tubular shafts being in the third lumen.

5. The intracardiac instrument of claim 4 wherein the second tubular shaft has a distal end disposed distally of a distal end of the first tubular shaft such that the exit port is distal to the viewing port.

6. The intracardiac instrument of claim 5 wherein the viewing tip comprises an inflatable member, the inflatable member having a distal extremity sealingly affixed to the second shaft and a proximal extremity sealingly affixed to the third tubular shaft in communication with the third lumen, wherein an inflation fluid may be delivered through the third lumen to the inflatable member.

7. The intracardiac instrument of claim 1 wherein the viewing tip comprises an inflatable member, the instrument body further comprising an inflation lumen in communication with the inflatable member.

8 The intracardiac instrument of claim 1 wherein the exit port is distal to the viewing port, the inflatable member having a distal extremity sealingly affixed to the instrument body around the exit port and a proximal extremity sealingly affixed to the instrument body proximal to the viewing port.

9. The intracardiac instrument of claim 1 wherein the interventional device comprises a suturing device comprising a tissue penetrating portion, a suture filament coupled to the tissue penetrating portion, and a driver configured to advance the tissue penetrating portion through tissue.

10. The intracardiac instrument of claim 9 wherein the suturing device is removably positioned in the instrument lumen and extends proximally from a proximal end of the instrument body.

11. The intracardiac instrument of claim 9 wherein the tissue penetrating portion comprises a needle releasably coupled to the driver and movable relative to the instrument body.

12. The intracardiac instrument of claim 11 wherein the needle is movable along an axis parallel to a longitudinal axis of the instrument body.

13. The intracardiac instrument of claim 11 wherein the needle is curved and the needle is movable rotationally about an axis of rotation.

14. The intracardiac instrument of claim 13 wherein the axis of rotation is parallel to a longitudinal axis of the instrument body.

15. The intracardiac instrument of claim 13 wherein the axis of rotation is transverse to a longitudinal axis of the instrument body.

16. The intracardiac instrument of claim 11 wherein the suturing device further comprises a target positionable at a target location aligned with a path of motion of the needle such that moving the needle through the path of motion engages the needle with the target.

17. The intracardiac instrument of claim 16 wherein the target is configured to retain the needle following engagement therewith.

18. The intracardiac instrument of claim 17 wherein the driver is retractable relative to the target following engagement of the needle therewith, the needle being released from the driver upon retraction.

19. The intracardiac instrument of claim 9 wherein the tissue penetrating portion comprises a helical anchor configured to be permanently implanted in cardiac tissue.

20. The intracardiac instrument of claim 19 wherein the driver comprises an elongated shaft having a holder at a distal end thereof configured to releasably hold the helical anchor and to drive the helical anchor into tissue by rotation thereof.

21. The intracardiac instrument of claim 20 wherein the suturing device further comprises an anchor release mechanism configured to allow selective release of the helical anchor from the holder.

22. The intracardiac instrument of claim 21 wherein the anchor release mechanism comprises a suture engagement element configured to hold the suture filament in tension while the helical anchor is driven into tissue, and to release the suture to allow the helical anchor to be released from the holder.

23. The intracardiac instrument of claim 1 wherein the viewing lumen is configured to removably receive an endoscope therein.

24. An intracardiac instrument comprising:

a shaft having a distal portion and proximal portion, a viewing lumen communicating with a viewing port in the distal portion, and a translucent viewing tip sealingly coupled to the distal portion over the viewing port; and

an end effector coupled to the distal portion of the shaft and extendable distally of the viewing tip, the end effector being configured to perform a function on intracardiac tissue;

wherein the translucent viewing tip is configured to displace blood away from the viewing port sufficiently to enable visualization through the viewing lumen of the end effector performing the function on the intracardiac tissue when the distal portion is immersed in a blood-filled field.

25. The intracardiac instrument of claim 24 wherein the end effector comprises a needle coupled to a suture.

26. The intracardiac instrument of claim 25 wherein the end effector is configured to drive the needle through the intracardiac tissue.

27. The intracardiac instrument of claim 24 wherein the end effector comprises an implantable anchor coupled to a suture.

28. The intracardiac instrument of claim 27 wherein the end effector is configured to drive the anchor into the intracardiac tissue.

29. The intracardiac instrument of claim 24 wherein the end effector is slidable longitudinally relative to the shaft.

30. The intracardiac instrument of claim 24 wherein the translucent viewing tip comprises an inflatable member.

31. The intracardiac instrument of claim 24 wherein translucent viewing tip is configured to atraumatically engage intracardiac tissue while the end effector engages the intracardiac tissue.

32. A method of performing surgery on a heart valve within a heart of a patient, comprising:

introducing an instrument through a wall of the heart such that a distal portion of the instrument is within a blood-filled heart chamber;

engaging intracardiac tissue with a translucent viewing tip of the instrument; engaging the intracardiac tissue with an end effector coupled to a distal portion of the instrument; and

viewing the intracardiac tissue in a blood-filled field through a viewing lumen of the instrument optically aligned with the translucent viewing tip while performing a function on the intracardiac tissue with the end effector, wherein the translucent viewing tip displaces blood from a distal end of the viewing lumen.

33. The method of claim 32 wherein the translucent viewing tip is inflatable.

34. The method of claim 32 wherein the function comprises applying a suture to the intracardiac tissue.