ATRAUMATIC CURVILINEAR ATRIAL RETRACTORS AND RELATED METHODS

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application Serial Number 60/754,112, filed December 27, 2005, the contents of which are hereby incorporated by reference as if recited in full herein.

FIELD OF THE INVENTION

The invention relates to tissue retractors for surgeries.

BACKGROUND OF THE INVENTION

During surgeries, surgical tools are introduced into the body to carry out a desired cutting, forming or ablation procedure in the target location in the body. Typically, one or more retractors can be used to provide a suitable access path or increased intra-body space for the tools to be able to reach the target location.

Relatively recently, a minimally invasive, robotic-assisted surgical system has been used to carry out closed chest (rather than open heart) cardiac surgeries. The closed chest surgeries can use both major and minor surgical access paths to allow for multiple instruments to be inserted into the body and used concurrently or serially during the procedure. One example of a cardio-surgical robotic-assisted system is the da Vinci® Surgical System by Intuitive Surgical Inc. of Sunnyvale, CA.

Using the robotic-assisted surgical system, a surgeon's hands do not typically enter the patient. After the formation of set-up incisions that are used to create the major or minor access paths, the surgeon controls the instruments, including at least one miniature camera used to carry out the surgery, from a console, usually located in the operating room, to guide the instruments into position and operate the instruments to carry out their intended functions. The camera provides real time (magnified) images of the operating site or access paths on a display that allows a surgeon to "see" the tools and operative site and remotely control the surgery.

There is a need for instruments and methods for alternative retractors, particularly retractors that can facilitate minimally invasive surgeries such as robotic- assisted cardiac surgeries.

SUMMARY OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention are directed to retractors and methods that can facilitate surgeries.

Certain embodiments provide retractors that are suitable for minimally invasive endoscopic and/or robotic-assisted cardiac surgeries. The retractors may be configured as an atrial lift retractor to facilitate intra-cardiac mitral valve repair procedures.

The retractors may be sized and configured to enter the body through a single small incision into the trans-thoracic cavity. The devices may be sized and configured to reside in situ proximate the mitral valve site at a left atria to splint open the mitral valve in response to robotic controlled direction of a surgeon for a mitral valve repair.

Some embodiments are directed to cardiac retractors that include a rod having opposing forward and rearward portions and a length sufficient to position the rearward portion of the rod outside a patient's body and the forward portion inside a patient proximate a lumen of cardiac tissue. The forward portion comprises a distal curvilinear portion that is sized and configured to reside in the left atrium and lift a roof of the left atrium.

The rod may have a cross-sectional width (such as diameter) of between about 1-5 mm, typically about 3 mm. The rod can cooperate with an external mount to hold the rod in a desired lifting position. Other embodiments are directed to methods of retracting cardiac tissue (and may be particularly suitable for use in a closed chest heart surgery). The methods include: (a) introducing an elongate rod having a distal curvilinear portion into a small opening in the chest into a trans-thoracic cavity; (b) placing the curvilinear portion of the into a left atrium so that a projecting portion thereof enters the left atrium; then (c) lifting a roof of the atrium using the projecting portion of the rod.

It is noted that any of the features claimed with respect to one type of claim- such as an apparatus or method, may be claimed or carried out as any of the other types of claimed operations or features.

Further features, advantages and details of the present invention will be

appreciated by those of ordinary skill in the art from a reading of the figures and the detailed description of the embodiments that follow, such description being merely illustrative of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a top perspective view of a tissue retractor according to embodiments of the present invention.

Figure 2 is a end perspective view the device shown in Figure 1. Figure 3 is a side perspective view of the device shown in Figure 1. Figure 4 is a flow chart of operational steps that can be used to carry out embodiments of the present invention.

Figure 5 presents cross-sectional views of exemplary rod configurations according to embodiments of the present invention.

Figures 6A-6C are partial schematic views of alternative curvilinear projecting shapes according to embodiments of the present invention.

Figure 7 is a schematic illustration of the tissue retractor in a use orientation and position according to embodiments of the present invention.

Figure 8 is a schematic illustration of a robotic-assisted surgical system for cardiac surgery with an atraumatic retractor rod according to embodiments of the present invention.

Figures 9A and 9B are digital images of the tissue retractor of Figure 1 shown in position in a left atrium according to embodiments of the present invention. Figures 10A-10E are schematic sequential illustrations of the tissue retractor of Figure 1 being introduced into the body according to embodiments of the present invention.

DETAILED DESCRIPTION

The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity. Broken lines illustrate optional features or operations unless specified otherwise. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as "between X and Y" and "between about X and Y" should be interpreted to include X and Y. As used herein, phrases such as "between about X and Y" mean "between about X and about Y." As used herein, phrases such as "from about X to Y" mean "from about X to about Y."

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

It will be understood that when an element is referred to as being "on", "attached" to, "connected" to, "coupled" with, "contacting", etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, "directly on", "directly attached" to, "directly connected" to, "directly coupled" with or "directly contacting" another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed "adjacent" another feature may have portions that overlap or underlie the adjacent feature.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. The sequence of operations (or steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise. Spatially relative terms, such as "under", "below", "lower", "over", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as "under" or "beneath" other elements or features would then be oriented "over" the other elements or features. Thus, the exemplary term "under" can encompass both an orientation of over and under. Similarly, the terms "upwardly", "downwardly", "vertical", "horizontal" and the like are used herein for the purpose of explanation only, unless specifically indicated otherwise.

The term "axially" and derivatives thereof mean in a generally lengthwise direction. The term "small incision" means an incision that is less than about 2 inches wide and/or long, typically between about 1-5 mm, and more typically between about 2-3 mm. The small incision for insertion of a rod can be disposed below or to the side of the sternum, and can be located above an intercostal space in the sternum while the chest is closed (no separation of the sternum is needed, although rib spreaders may optionally be used).

The term "endoscopically" refers to a minimally invasive surgery that uses an endoscope and/or a robotic-assisted system. The endoscope and/or robotic system can include a camera and video (for providing real-time vision of the internal site) and can include a lighted medical instrument comprising a long tube that can be inserted into the body, usually through a small incision and/or cannula defining an intraoperative access.

The term "atraumatic" means that the device can be introduced into the body without major trauma, i.e., typically using a single small incision or "surgically implemented stab" entry. The term "generally U-shaped" refers to shapes that have a closed rounded or pointed projection and includes U, V, J and variant shapes thereof. The surgical instruments described herein may be particularly suitable for robotic-assisted cardiac surgeries in which the heart of the patient is arrested for a brief period while the patient is placed on a heart-lung machine so that a surgeon can operate. For example, surgeries of the left atrium are carried out to repair, remove and/or replace faulty valve tissue (or the mitral valve itself). Robotic-assisted closed- chest cardiac surgeries are typically carried out using a small thoracotomy and several thoracoports to provide operative visibility and access to the target cardiac site. However, the surgical instruments may also be used for other surgeries, typically minimally invasive surgeries, of other target regions in the body, within or outside the mediastinum. For clarity of description, the invention(s) will be discussed primarily below in relationship to robotic-assisted closed chest cardiac surgeries. However, the instruments and methods are not limited thereto as they can be useful for other surgeries such as non-robotic, endoscopic or general surgeries and/or for retracting non-cardiac tissue or other target organs or tissue. Generally stated, in robotic mitral repairs, sutures for annular closure, intraleaflet closure and/or annuloplasty can be placed robotically using, for example, 2-0 braided sutures and 4-0 monofilament sutures, all of which may be shortened to a desired length beforehand. A side surgeon can cut and retrieve the sutures using conventional scissors and forceps after ligation of the sutures. The number of sutures can vary with a patient, but for a quadrantectomy, more than 10 sutures are typically used with the ordinary sliding technique, and in an annuloplasty, between about 10-14 sutures can be used.

During certain cardiac procedures; when a patient is placed on a heart-lung machine, the heart can collapse against itself. To obtain sufficient visual and surgical exposure to allow for surgical access, different types of retractors can be used. For example, a lifting retractor can lift the heart.

Embodiments of the present invention can increase visualization of operative field or site, and may be particularly useful in minimally invasive mitral valve surgeries (or mitral valve surgeries combined with Maze procedures for atrial

fibrillation) to open the left atrium just posterior to the intra-atrial groove and anterior to the right pulmonary veins to expose the mitral valve without unduly interfering with robotic instruments or arms.

Figures 1 and 2 illustrate an exemplary embodiment of a tissue retractor rod 10. As shown, the retractor 10 has a distal end wilh a curvilinear projecting portion 11 defined by first and second axially extending segments 12, 14, each having opposing first and second end portions 12i, 122, 14i, 14 ₂ . The first and second segments 12, 14 merge into each other at the respective second end portions 12 ₂ , 14 ₂ . The retractor rod 10 also has an elongate generally vertical segment 18 (typically substantially vertical) and may include a generally horizontal external handle portion 19. As also shown, the first end portion 14i of the second segment 14 includes an upwardly extending angled transition neck portion 14t that merges into the elongate rod segment 18. The first end portion 12i of the first segment 12 defines a leading edge 12e that is configured to be introduced first into the opening in the body. The first and second segments 12, 14 can define a forwardmost curved portion lie and the first and second end segments can form an open gap space Hg rearward thereof. The projecting portion can have a length "L" that is between about 40 mm to about 60 mm and a width "W" that is between about 25 mm to about 40 mm.

The retractor rod 10 can have a unitary body with sufficient rigidity to provide the desired tissue retraction. In other embodiments, the rod 10 can be formed via a series of attached segments. The retractor rod 10 may comprise metal, ceramic, composite and/or elastomeric material, or combinations of same. The retractor 10 may be single use and disposable or reuseable (after sterilization).

The rod 10 can have a cross-sectional width or thickness sized for atraumatic introduction via a single small incision, stab wound or other opening in the body. The cross-sectional width can be between about 1- 5 mm, typically between about 2-4 mm, and more typically about 3 mm. The rod 10 can have a length that is between about 10-80 cm, typically about 30-60 cm. The rod 10 can be formed with a biocompatible material and/or coated with a biocompatible material, hard-coat or gel to promote slidability, decrease friction and/or facilitate insertion.

In some embodiments, the rod 10 can be inserted through a surgically introduced "stab" or incision entry that can be about a 3 mm skin incision. The rod 10 can be "threaded" or "fished" into the body, turning the rod 20 to enter the single incision or opening using different rod orientations to place the lower curvilinear 11

portion of rod inside the left atrium, typically so that the closed end faces the mitral valve.

As shown in Figure 3, the curvilinear projecting portion of the rod 10 can be generally planar, and substantially orthogonal to the generally vertical segment 18. However, non-planar configurations may also be used. As is also shown, the handle 19 is sized and configured for manipulation by a surgeon's fingers. However, the handle 19 is not required and other external end portion configurations may be used. Figure 4 illustrates exemplary operational steps that may be used to retract tissue in heart surgery. An elongate rod having a distal curvilinear portion is introduced into a small opening in the chest into a trans-thoracic cavity (block 105). The curvilinear portion of the rod is placed into a left atrium so that a projecting portion thereof enters the left atrium (block 110). Then, a roof of the atrium is lifted using the projecting portion of the rod (block 115).

In some embodiments, the method is carried out during a closed chest robotic- assisted surgery (block 106) and/or can be used to carry out a mitral valve repair (block 108).

Figure 5 illustrates that the rod 10 can have various geometric cross-sectional shapes, exemplary shapes being indicated. The rod 10 can have the same cross- sectional width and/or shape over its entire length or may have varying widths and/or shapes over its length. Figures 6A and 6B illustrate exemplary distal curvilinear projecting portions 11. Figure 6 A illustrates that the first and second segments 12, 14 may have substantially the same length and the forward portion may be arcuately curved lie. Figure 6B illustrates that the first segment 12 may be shorter than the second segment 14. Figure 6C illustrates that the forward portion of the projection 11 may be more pointed than curved.

Figure 7 illustrates the retractor 10 in an exemplary use orientation. In this embodiment, the retractor 10 is disposed so that the closed portion of the projection 11 can enter a lumen, such as the left atrium 200 upstream of the mitral valve 20Ov. In other embodiments, the open end can enter a target lumen. The curvilinear portion 11 is able to lift tissue 201 to better expose a surgical access path or target surgical site. The compact configuration of the retractor 10 allows for multiple interventional robotic controlled and/or endoscopic tools to be used concurrently with the retractor 10.

As also shown in Figure 8, the cardiac tissue retractor 10 may releasably attach to an external mounting (stabilizer) fixture 30 that can hold the rod 10 in a desired intra-body orientation and position. The external mounting fixture 30 shown can be a flexible snake arm that may have adjustable rigidity and may attach to a table, bed or floor fixture. The fixture 30 may also attach to a rib spreader or chest mounted fixture. However, other types of mounting fixtures can be used, whether chest mounted or mounted remotely off the patient. An example of a commercially available snake arm is the XPOSE cardiac stabilizer from Guidant Corporation, located in Santa Clara, CA. See also, U. S. Patent Nos. 6,758,809, 6,740,028, and 6,581 ,889, the contents of which are hereby incorporated by reference as if recited in full herein.

In some embodiments, the rod 10 may be configured to be inserted percutaneously through an incision in the chest into the thoracic cavity. In some embodiments, the rod 10 may be tapered from a smaller front edge portion to a larger medial portion at the first segment 12 to allow for easier penetration of an incision {i.e., the front edge portion 12e enters the incision first).

Figure 8 illustrates a robotic-assisted system 300 positioned to carry out a closed-chest surgical procedure. For more description of robotic systems and/or components, see, e.g., U.S. Patent Nos. 6,936,042; 6,522,906; 6,371,952; 6,364,888; 6,346,072; 6,331,181; 6,312,435; 6,309,397; 6,246,200; 6,206;903; and 6,132,368, the contents of which are hereby incorporated by reference as if recited in full herein. See also, Ng et al., "Robotic surgery" IEEE Engineering in Medicine and Biology (1993) 120-125.

As shown in Figure 8, the rod 10 is inserted into the chest wall. A surgical access opening 75 proximate the xiphoid process or tip of the sternum cavity can be used to position the camera or other robotic instruments. Supplemental incisions for side entry via percutaneous penetration can provide additional, typically minor, surgery access paths 176, 177 to the heart or great vessel (or other target regions) to allow surgery via visualization of the target site. One or more paths 175-177 (or even additional paths) can be used by one or more surgeons for inserting tools used to carry out minimally invasive surgeries, such as endoscopic procedures. These paths 175- 177 can be particularly suitable for robotic-assisted systems as noted above. Tools can be inserted serially through each path, and in some embodiments, cooperating

tools can be inserted concurrently, one or more through a different access path to meet at a common location in situ.

One or more of the entry paths, such as the side or minor entry paths 176, 177, can be defined by an intra-body port with a cannula (also generally known as a trocar). In some embodiments, one or more intra-body ports can be provided by a small cannula, typically one that is between about 5-30 mm wide, and more typically about 10-20 mm wide. An example of a commercially available port suitable for providing side access paths, is the THORACOPORT™ cannula, available from U.S. Surgical, Inc., a division of Tyco Healthcare, having a place of business in Norwalk, CT.

Figures 9A and 9B are digital images of a left atrium 200 with the retractor 10 used to lift a roof of the atrium. The closed end portion of the curvilinear projection 11 faces the mitral valve 20Ov.

Figures 10 A-IOE illustrate a sequence of steps that can be used to position and use the retractor according to embodiments of the present invention. As shown in Figure 1OA, the leading edge 12e of the rod 10 can be inserted through a small incision in the chest, typically into a trans-thoracic cavity generally above the left atrium via an intercostal space. The rod access path can be defined via a "blind stick". Remote viewing via a video or camera of the use location can be used to position the rod in situ.

After the leading edge 12e is introduced into the opening, the rest of the first segment 12 is introduced into the incision or opening and into the chest cavity. The rod 10 is turned as the second segment 14 approaches and/or enters the opening and the surgeon continues to advance the rod 10 to place the second segment 12 into the cavity. The rod 10 is turned again so that the proximal rod segment 18 is generally vertical and the rod 10 is further advanced into the cavity to position the curvilinear projecting portion 11 proximate target tissue for axially introducing into the left atrium or other target lumen.

An operative access path can be left substantially open or free to allow robotic controlled devices to access a mitral valve repair site upstream of the retractor member 10 while the retractor 10 is in position.

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications

are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.