US20090137865A1 - Tissue Stabilizer and Methods of Use - Google Patents

Abstract

Devices and methods are disclosed for stabilizing tissue within a patient's body during a surgical operation to provide a relatively motionless surgical field. The devices involve tissue stabilizers which provide superior engagement with a tissue structure to be stabilized, for example the beating heart. The tissue stabilizer may have one or more stabilizer feet which provide for adjustment of the orientation of the features which engage the surface of the tissue structure. In one instance, the orientation may be adjusted to ensure the engaging features will be properly aligned with the surface of the tissue structure before engagement. In addition, once engaged with or connected to the tissue structure the orientation may be adjusted to yield an optimum surgical presentation of a portion of the tissue structure, for instance a coronary artery or the like. The tissue stabilizer may be configured to use friction, negative pressure, or both to engage the surface of the heart.

Description

FIELD OF THE INVENTION
• The present invention relates generally to surgical instruments, and more particularly to methods and apparatus for stabilizing or immobilizing tissue during surgery. The tissue stabilizers described herein are particularly useful for stabilizing the beating heart during coronary artery bypass graft surgery.
BACKGROUND OF THE INVENTION
• Certain surgical procedures require the surgeon to perform delicate operations on tissues within the body that are moving or otherwise unstable. The ability to stabilize or immobilize the surgical site provides greatly improved surgical accuracy and precision and reduces the time required to complete a particular procedure. A large and growing number of surgeons, for example, are routinely performing successful coronary artery bypass graft (CABG) surgery on the beating heart by temporarily stabilizing or immobilizing a localized area of the beating heart. Methods and apparatus for performing a CABG procedure on the beating heart are described in U.S. Pat. No. 5,894,843 and U.S. Pat. No. 5,727,569 to Benetti et al., the entirety of which is herein incorporated by reference.
• In a typical CABG procedure, a blocked or restricted section of coronary artery, which normally supplies blood to some portion of the heart, is bypassed using a source vessel or a graft vessel to re-establish blood flow to the artery downstream of the blockage. This procedure requires the surgeon to create a fluid connection, or anastomosis, between the source or graft vessel and an arteriotomy or incision in the coronary artery. Forming an anastomosis between two vessels in this manner is a particularly delicate procedure requiring the precise placement of tiny sutures in the tissue surrounding the arteriotomy in the coronary artery and the source or graft vessel.
• The rigors of creating a surgical anastomosis between a coronary artery and a graft or source vessel demands that the target site for the anastomosis be substantially motionless. To this end, a number of devices have been developed which are directed to stabilizing a target site on the beating heart for the purpose of completing a cardiac surgical procedure, such as completing an anastomosis. Representative devices useful for stabilizing a beating heart are described, for example, in U.S. Pat. Nos. 5,894,843; 5,727,569; 5,836,311; and 5,865,730.
• As beating heart procedures have evolved, new challenges have arisen in the design and engineering of the stabilization devices. The heart is typically accessed by way of a surgical incision such as a sternotomy or thoracotomy. Often one or more of the blocked or restricted coronary arteries are located a good distance away from the access incision requiring the stabilization device to traverse a longer and more tortuous path and engage the surface of the heart at somewhat difficult angular relationships or orientations. Under the most severe conditions, devices which operate to provide a mechanical compression force to stabilize the beating heart encounter difficulty maintaining mechanical traction against the surface of the heart. Similarly, devices which utilize vacuum to engage the heart have a great deal of difficulty creating and maintaining an effective seal against the moving surface of the heart.
• Even when the beating heart has been effectively stabilized, the target coronary artery may be obscured by layers of fat or other tissue and is very difficult for the surgeon to see. Moreover, the stabilization devices may distort the tissue surrounding the coronary artery or the coronary artery itself such that the arteriotomy is maintained in an unfavorable presentation for completion of the anastomosis. For example, the coronary artery in the area of the arteriotomy may become excessively flattened, compressed or stretched in a manner that impedes the placement of sutures around the perimeter of the arteriotomy.
• In view of the foregoing, it would be desirable to have methods and devices for stabilizing the beating heart that are capable of maintaining atraumatic engagement with the surface of the beating heart over a wider range of conditions and orientations. It would be further desirable to have stabilization methods and devices which provide for favorable presentation of the coronary artery.
SUMMARY OF THE INVENTION
• The present invention will be primarily described for use in stabilizing the beating heart during a surgical procedure, but the invention is not limited thereto, and may be used in other surgical procedures.
• The present invention is a tissue stabilizer having one or more stabilizer feet that may be adjusted or oriented to provide optimal engagement against the tissue to be stabilized or to provide an optimal presentation of a portion of the stabilized tissue. The present invention may also include a tissue stabilizer having one or more flexible or compressible seals to ensure a reliable seal against the target tissue and may also include a stabilizer foot having at least one portion which is adjustable relative to the remainder of the stabilizer foot.
• One aspect of the present invention involves a device for stabilizing tissue within a patient's body comprising a base member, a first stabilizer foot extending outwardly from the base member and being rotatable relative to the base member about a first axis, and a second stabilizer foot extending outwardly from the base member and being rotatable relative to the base member about a second axis. Preferably, the first and second stabilizer feet are independently rotatable relative to the base member. In a preferred embodiment, the first axis and the second axis are substantially parallel.
• The first and second stabilizer feet may each have hollow interiors defining first and second vacuum chambers each having at least one opening adapted to engage at least a portion of the tissue. The openings adapted to engage at least a portion of the tissue to be stabilized may have a raised seal around a perimeter thereof. In one variation the raised seal is made of a substantially rigid material. In other variations the raised seal is made of an elastomeric material or a compressible foam material.
• The base member may comprise an interior chamber therein, the interior chamber of the base member being in fluid communication with the first and second vacuum chambers. The base member may comprise a front base portion and a rear base portion, the front base portion being sealingly affixed to the rear base portion. The device may also include a post having a distal end connected to the base member and a proximal end terminating in a ball-shaped member. A shaft may be provided having a socket at a distal end, the socket being operably engaged with the ball.
• Another aspect of the present invention involves a device for stabilizing tissue within a patient's body having a base member and at least one stabilizer foot extending outwardly from the base member in a first direction, the stabilizer foot being rotatable relative to the base member about an axis of rotation which is oriented in substantially the same direction as the first direction. Preferably, the axis of rotation is at an angle of no more than about 25° to the first direction, more preferably, the axis of rotation is substantially parallel to the first direction.
• In a preferred variation, the stabilizer foot has tissue engaging features adapted to engage an external surface of the tissue to be stabilized, the tissue engaging features being disposed at the bottom of the stabilizer foot. The tissue engaging features may comprise a vacuum chamber, preferably having a single opening for engaging the tissue to be stabilized, or may comprise a plurality of vacuum ports. The tissue engaging features may also comprise a textured surface, a perforated sheet, or a perforated sheet having projections extending outwardly therefrom. Preferably, the axis of rotation of the stabilizer foot is offset from the tissue engaging features, more preferably offset from and parallel to the tissue engaging features.
• The stabilizer foot may have a hollow interior defining a vacuum chamber with a bottom opening adapted to engage at least a portion of the tissue. The stabilizer foot may also have a raised seal disposed around a perimeter of said opening, preferably around substantially the entire perimeter. The raised seal may be made from a rigid material, an elastomer, or a compressible foam. The vacuum chamber may have an inlet passage in fluid communication with a source of negative pressure. Preferably, the inlet passage is in fluid communication with an interior chamber within the base member. The base member may include an external fluid connection to supply negative pressure to the interior chamber of the base member.
• Another aspect of the present invention involves a device for stabilizing a coronary artery on a patient's heart comprising a base member and a stabilizer foot for engaging a portion of the patient's heart. The base member has an interior chamber and at least a first bore, typically a cylindrical bore, having a first end in fluid communication with the interior chamber of the base member and a second end open to the exterior of the base member. The stabilizer foot has a substantially cylindrical fitting having a longitudinal axis, at least a portion of the fitting positioned within the bore and being rotatable within the bore about the longitudinal axis.
• The stabilizer foot may have a hollow interior defining a vacuum chamber, the vacuum chamber having at least one chamber opening adapted to engage at least a portion of the heart. The fitting may further have a fluid passage having a first end in fluid communication with the interior chamber of the base member and a second end in fluid communication with the vacuum chamber of the stabilizer foot. A raised seal may be disposed substantially completely around the perimeter of the chamber opening. The raised seal may be rigid, compressible or flexible, preferably compressible or flexible. In a preferred embodiment, the raised seal has a durometer with a valve in the range of between about 35 Shore-A to about 100 Shore-A.
• The stabilizer foot fitting may comprise a flange and further include an annular seal positioned adjacent the flange. Preferably, the annular seal is positioned between the flange and the base member. The annular seal is preferably an O-ring. The fitting includes at least one flexure having a free end and a raised portion extending radially from the free end. The raised portion preferably engages the first end of the first cylindrical bore to restrict movement of the fitting relative to the base member.
• The tissue stabilizer may further include a second substantially cylindrical bore having a first end in fluid communication with the interior chamber of the base member and a second end open to the exterior of the base member. The tissue stabilizer may have a second stabilizer foot having a substantially cylindrical fitting having a longitudinal axis, at least a portion of the second stabilizer fitting positioned within the second bore and being rotatable within the second bore about the longitudinal axis of the fitting of the second stabilizer foot.
• Another aspect of the present invention involves a stabilizer foot for use in engaging a portion of tissue within a patient's body which includes a first foot portion having at least one vacuum port, a second foot portion having at least one vacuum port, and at least one malleable member connecting the first foot portion to the second foot portion, whereby the orientation of the first foot portion can be adjusted relative to the second foot portion. Preferably, the first foot portion is a substantially rigid unitary member having at least two vacuum ports.
• The first foot portion may have a fluid passage in fluid communication with each of the vacuum ports associated with the first foot portion and the second foot portion may have a fluid passage in fluid communication with each of the vacuum ports associated with the second foot portion. The malleable member may be a cylindrical tube having a first end, a second end, and a lumen extending therebetween, the lumen fluidly connecting the fluid passage of the first foot portion with the fluid passage of the second foot portion, preferably, the tube is made of stainless steel. In another variation, a flexible tube may be provided to connect the fluid passage of the first foot portion to the fluid passage of the second foot portion. The malleable member is then preferably offset from the flexible tube. Preferably, the stabilizer foot includes two malleable members offset from opposing sides of the flexible tube.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIGS. 1A and 1B are top plan and top perspective views, respectively, of a tissue stabilizer constructed according to the principles of the present invention.
• FIG. 2 is a bottom perspective view of the tissue stabilizer ofFIGS. 1A and 1B.
• FIG. 3 is a cross-sectional view taken along line3-3 as shown inFIG. 1A.
• FIG. 4 is a cross-sectional view taken along line4-4 as shown inFIG. 1A.
• FIG. 5 is a bottom perspective view of an alternate construction of a tissue stabilizer according to the principles of the present invention.
• FIG. 6 is an exploded perspective view of a tissue stabilizer.
• FIG. 7 is an exploded perspective view of an alternate construction of a tissue stabilizer.
• FIG. 8A is a magnified partial perspective view of a contacting surface of a preferred perforated screen for use in a tissue stabilizer.
• FIG. 8B is a partial cross-sectional view showing the perforated screen configuration ofFIG. 8A engaged against a tissue structure.
• FIGS. 9A and 9B are partial cross-sectional views of a tissue stabilizer foot having a perimeter seal.
• FIG. 10 is a partial cross-sectional view of a tissue stabilizer foot having an alternate perimeter seal.
• FIG. 11 is a partial cross-section view of a tissue stabilizer foot having an alternate perimeter seal.
• FIG. 12 is a top plan view of a tissue stabilizer having an alternative perimeter seal.
• FIG. 13A is a top perspective view of the stabilizer foot ofFIG. 12.
• FIG. 13B is a cross-sectional view taken alongline13B-13B as shown inFIG. 13A.
• FIG. 14 is a bottom perspective view of an alternate construction of a tissue stabilizer according to the principles of the present invention.
• FIG. 15 is a cross-sectional view of one of the stabilizer feet ofFIG. 14.
• FIG. 16 is a bottom plan view of an alternate construction of a stabilizer foot according to the principles of the present invention.
• FIG. 17 is a cross-sectional view taken along line17-17 as shown inFIG. 16.
• FIG. 18 is a bottom plan view of an alternate construction of a stabilizer foot.
• FIG. 19 is a cross-sectional view taken along line19-19 as shown inFIG. 18.
• FIG. 20 is a bottom plan view of an alternate construction of a stabilizer foot.
• FIG. 21 is a cross-sectional view taken along line21-21 as shown inFIG. 20.
• FIG. 22 is a partial cross-sectional view of an alternate construction of a tissue stabilizer according to the principles of the present invention.
DETAILED DESCRIPTION
• The present invention involves surgical instruments and methods for stabilizing tissue during a surgical operation. The devices described herein may be used in a wide variety of surgical applications that require a tissue structure to be stabilized or immobilized to provide a substantially stable and motionless surgical field on which a surgical procedure can be performed. By way of example only, the preferred embodiments described in detail below are directed to the stabilization of a portion of the heart to facilitate a surgical procedure on or within the heart, such as a coronary artery bypass graft (CABG) procedure.
• Although the devices and methods of the present invention may have application in both conventional stopped-heart and beating heart procedures, they are preferably used to stabilize the beating heart during a CABG operation which has been specially developed to facilitate completion of an anastomosis, typically between a target coronary artery and a bypass graft or source artery, without requiring cardiac arrest and cardiopulmonary bypass.
• A typical beating heart CABG procedure involves accessing the beating heart by way of a sternotomy, mini-sternotomy, thoracotomy, mini-thoracotomy, or other suitable access incision, positioning a tissue stabilizer on, around or adjacent a coronary artery to stabilize the coronary artery, creating an arteriotomy in the coronary artery, and anastomosing the bypass graft or source artery to the arteriotomy. Typically, the tissue stabilizer has a heart engaging member at one end for engaging the surface of the beating heart and is connected at the other end to a stationary object such as a sternal retractor, rib retractor, or other such stationary structure. Exemplar devices and methods for accessing the beating heart and mounting a stabilizer device are disclosed in co-pending U.S. patent application Ser. No. 09/305,810 titled “A SURGICAL RETRACTOR APPARATUS FOR OPERATING ON THE HEART THROUGH AN INCISION”, the entirety of which is herein incorporated by reference.
• The devices of the present invention involve tissue stabilizers which provide superior engagement with the surface of the heart. In preferred embodiments of the present invention, the tissue stabilizer may have one or more stabilizer feet which provide for adjustment of the orientation of the features which contact or engage the surface of the heart. In one instance, the orientation may be adjusted to ensure the engaging features will be properly aligned with the surface of the heart. In addition, once engaged with or connected to the heart, the orientation may be adjusted to yield an optimum presentation of the target coronary artery and, in particular, the location at which the anastomosis will be performed.
• When the tissue stabilizer is configured to facilitate the use of negative pressure to engage the surface of the heart, the stabilizer feet may include one or more compliant or flexible seals to ensure that there will be no vacuum leaks between the stabilizer foot and the surface of the heart. To ensure that the engaging features provided on a stabilizer foot will closely approximate the surface of the beating heart under operating conditions, the stabilizer foot may have one or more portions which are adjustable relative to each other so that the stabilizer foot may be shaped according to the requirements of a particular surgical procedure or according to the specific anatomical features or characteristics of each individual patient.
• Referring to the figures wherein like numerals indicate like elements, an exemplar tissue stabilizer is illustrated inFIGS. 1A-4.Tissue stabilizer100 preferably hasstabilizer feet105 and110 which typically engage the surface of the heart on opposite sides of a coronary artery.Tissue stabilizer100 is typically positioned such that the coronary artery runs lengthwise in the space betweenstabilizer feet105 and110.
• For beating heart procedures where the target vessel is occluded,tissue stabilizer100 preferably has a construction that does not occlude or otherwise contact the vessel asstabilizer feet105 and110 are placed on opposite sides of the coronary vessel portion to be stabilized. Thus,stabilizer feet105,110 are spaced apart at a distance such that a coronary artery can be positioned therebetween. Whenstabilizer feet105 and110 are connected to a common base, the base may include a recessed or raised portion to ensure that the vessel is not contacted by the stabilizer. For example,manifold base120, to whichstabilizer feet105 and110 are attached, preferably has raisedportion126 under which the coronary vessel may pass without contact whenstabilizer feet105 and110 are engaged to stabilize the heart in the vicinity of the coronary vessel.
• Stabilizer feet105 and110 are connected tomanifold base120 which will typically have mounting or connecting features for operably attaching a suitable shaft or other such structure. Preferablymanifold base120 has aball135 extending therefrom. A shaft (not shown), preferably having a suitably constructed socket, may be provided to engageball135. The shaft may be used to positiontissue stabilizer100 at the desired location on the heart and may provide the necessary structure to hold the tissue stabilizer substantially motionless against the forces generated by the beating heart. Of course, the shaft or other appropriate connecting structure may be operably connected to the tissue stabilizer using any suitable connection which allows the desired maneuverability of the tissue stabilizer relative to the shaft. Suitable stabilizer shafts and their connections to a tissue stabilizer are described in co-pending U.S. patent application Ser. No. 08/931,158, titled “SURGICAL INSTRUMENTS AND PROCEDURES FOR STABILIZING THE BEATING HEART DURING CORONARY ARTERY BYPASS GRAFT SURGERY”, and in EPO Application 97102789.1, the entirety of each are herein incorporated by reference.
• Stabilization of the targeted tissue may be achieved by applying a localized compressive force to the heart throughstabilizer feet105 and110 using an appropriate connecting structure attached toball135. In that case, the tissue contacting features on the bottom ofstabilizer feet105 and110 are designed to have high friction against the surface of the heart, for example, by using a textured surface or the like. If desired, negative pressure or vacuum may be applied tostabilizer feet105 and110 so that the beating heart may be engaged or captured by the suction created within a vacuum chamber or a plurality of suction ports. With a localized portion of the beating heart so engaged againststabilizer feet105 and110, the heart portion may be rendered substantially motionless by fixing an attached shaft to a stationary object, such as a surgical retractor as described above.
• Continuing to refer toFIGS. 1A-4,ball135 is preferably connected tomanifold base120 by way ofpost130.Ball135 and post130 may have any suitable construction which provides the necessary attachment of the stabilizing shaft or other stabilizing structure and which can withstand the loads required to stabilize the beating heart with minimal deflection. The ball and post may be integrally molded features on the manifold base itself or may be separate components mechanically secured tomanifold base120 using, for example, a threaded or snap-fit connection or the like.
• Whenmanifold base120 is constructed of a plastic material, it may be desirable to fixpost130 to a relatively rigid support member to help spread stabilization loads transmitted throughpost130 over a larger area ofmanifold base120. Preferably, post130 is rigidly attached to supportmember155 which is made of a metal such as aluminum or stainless steel. In a preferred embodiment,support member155 is secured within holding features such as cavities or pockets156 and158 formed inrear manifold portion124 andfront manifold portion122, respectively.Support member155 may be secured withinpockets156 and158 by a simple interference fit asmanifold portions122 and124 are urged into their final assembled positions or may be held in place using mechanical fasteners, adhesive, or suitable bonding or welding technique.
• When the tissue stabilizer is configured to use vacuum stabilization or vacuum-assisted stabilization,manifold base120 preferably has a fitting or the like to which a vacuum supply may be connected. In a preferred embodiment,manifold base120 hasinlet tube115 having aninlet opening117.Inlet tube115 is preferably in fluid communication with a hollow space orchamber134 formed withinmanifold base120.Manifold base120 andinternal chamber134 provides for convenient distribution of a single vacuum source connected toinlet tube115 to multiple stabilizer feet fluid connections, in this case tostabilizer feet105 and110.Inlet tube115 may have one ormore barbs119 to facilitate the secure and leak-free attachment of a length of flexible tubing (not shown) coming from a vacuum pump or other vacuum source (not shown) as is commonly known in the art. In an alternative embodiment,inlet tube115 may be replaced with a generally cylindrical bore adapted to accept an O-ring sealed fitting forming a dynamically sealed rotating connection between the fitting and the manifold base similar in construction to the stabilizer foot connection described below with regard toFIG. 3.
• For ease of manufacturing,manifold base120 is preferably made in two or more portions and fixed together to form a sealed, hollow interior. In a preferred embodiment,manifold base120 has frontmanifold portion122 andrear manifold portion124 which may be bonded together alongbond line125 as shown. Theinternal chamber134 may reside primarily in either or both of front and rearmanifold portions122 and124. To maximize the volume ofinternal chamber134 for a given outer-profile ofmanifold base120, a portion ofinternal chamber134 is formed inrear manifold portion124 and one or moreinternal cavities128 are included withinfront manifold portion122.
• The manifold portions are preferably injection molded and may be fixed together using standard mechanical fasteners, a snap fit construction, or any suitable adhesive, bonding, sealing, or welding technique compatible with the material ofmanifold base120. To facilitate reliable bonding between the manifold portions, the manifold portions may have close fitting overlapping flanges. In a preferred embodiment, best illustrated inFIG. 3,rear manifold portion124 has aninner flange152 andfront manifold portion122 has an overlappingouter flange154. This construction provides a particularly reliable sealed junction between front and rearmanifold portions122 and124, especially when used in conjunction with a suitable gap-filling adhesive.
• As mentioned above,stabilizer feet105 and110 are secured tomanifold base120.Stabilizer feet105 and110 may be fixed in place in any convenient manner and immovable relative tomanifold base120. More preferably, however,stabilizer feet105 and110 are moveable relative tomanifold base120. Most preferably,stabilizer feet105 and110 are independently moveable with respect to each other as well. This allows the tissue engaging features of the tissue stabilizer to be optimally adjusted with respect to the size and shape of the tissue to be stabilized and, once engaged and in operation, may also allow the stabilizer feet to be moved to optimize the presentation of the stabilized tissue, and more particularly the target coronary artery.
• In a preferred embodiment,stabilizer feet105 and110 are connected tomanifold base120 in a manner which allows each foot to rotate relative to themanifold base120. The axis about which thestabilizer feet105 and110 rotate may be in any orientation that provides the desired stabilizer feet orientation relative to the heart for optimum engagement or tissue presentation. Typically, the axis of rotation is oriented generally in the same direction as thedirection stabilizer feet105 and110 extend frommanifold base120, although the axis of rotation and the direction the stabilizer feet extend may be offset from each other. Thus, the axis of rotation of the first stabilizer foot relative to the base member may be offset from the axis of rotation of the second stabilizer foot relative to the base member.
• In a preferred embodiment, the axis of rotation is preferably at an angle of no more than about 25° with respect to the included plane or surface approximated by the features adapted to engage the tissue surface to be stabilized. More preferably, the axis of rotation for eachstabilizer foot105 and110 is generally parallel to the features adapted to engage the tissue surface to be stabilized. When the tissue engaging features are curved to have a radius of a constant or varied radius or an otherwise non-planar, the axis of rotation is oriented as described above relative to a best-fit plane approximating the tissue engaging features or a central tangent plane. Most preferably, the axis of rotation for each stabilizer foot is also angled with respect to each other at an angle of no more than about 30°, and more typically the axis of rotation ofstabilizer foot105 is generally parallel to the axis of rotation ofstabilizer foot110.
• Referring toFIG. 3, a preferred stabilizer foot connection is illustrated withrespect stabilizer foot110.Manifold base120, and more specificallyfront manifold portion122, has abore149 extending through the exterior wall.Stabilizer foot110 has an end portion or fitting137 having anoutside diameter148 adapted to mate withbore149 to allow fitting137, and thusstabilizer foot110, to rotate aboutcentral axis133 ofbore149. In the configuration shown,central axis133 is offset from the features which engage the tissue to be stabilized, in this case perforatedscreen141. This offset facilitates improved vessel presentation asstabilizer feet105 and110 are rotated because, in addition to changing the overall orientation of the tissue engaging features, the eccentric relation of the tissue engagement features relative to the central axis moves the stabilizer feet together or apart as the stabilizer feet are rotated. This action allows the tissue and included coronary artery held between the stabilizer feet to be stretched or compressed as desired by rotating either or both ofstabilizer feet105 and110 after they have become operably engaged with the tissue.
• In a preferred embodiment of the present invention, thetissue stabilizer100 is constructed to supply a negative pressure or vacuum tostabilizer feet105 and110 to assist in the engagement of the surface of the heart.Stabilizer feet105 and110 preferably have ahollow interior132 to which a vacuum may be supplied throughvacuum inlet131 of fitting137,vacuum chamber134, andvacuum inlet tube115, which are interconnected in a manner which does not allow any significant vacuum leaks. Collectively, the structures comprise a vacuum conducting chamber that communicates a negative pressure from a vacuum source to the surface of the beating heart.Vacuum inlet tube131 may optionally have restriction or aperture (not shown) provided therein to restrict the amount of flow throughvacuum inlet tube131 when the sealed engagement against the tissue to be stabilized is broken. This allowsvacuum chamber134 ofmanifold base120 to continue to provide sufficient vacuum to one stabilizer foot even when the engagement seal of the other stabilizer foot is compromised.
• To allow vacuum to be communicated to the engagement features ofstabilizer feet105 and110, the rotating connection betweenstabilizer feet105 and110 andmanifold base120 must be sealed to prevent any vacuum loss. This preferably accomplished using an appropriate dynamic annular or shaft seal that seals between the stabilizer foot andmanifold base120 but yet allows for rotation of the stabilizer foot withinbore149 without incurring any vacuum loss. Preferably, a seal such as O-ring145 is positioned within anannual seal cavity146 at the entrance ofbore149. The seal is captured and compressed withinseal cavity146 by cooperatingannular seal flange147 provided onstabilizer feet105 and110 as the stabilizer feet are urged into final position.Stabilizer feet105 and110 may be held in position by operation of an spring clip ore-clip150 assembled to fitting137 just beyond its exit ofbore149.
• Hollow interior132 is generally a closed chamber except for one or more openings for engaging the heart. As will be discussed in more detail below, the engagement opening or openings may be in the form of a perforated screen having a relatively large number of perforations or small holes which engage the surface of the heart, a single opening having a defined perimeter for sealing against the surface of the heart, or a plurality of individual suction pods each having a sealing perimeter.
• Referring toFIGS. 2 and 3,stabilizer feet105 and110 include thin perforated sheets or screens140 and141, respectively which have afront surface144 oriented to engage the surface of the heart.Perforated screens140 and141 are supported around their perimeter by asupport step138 which preferably has a raised perimeter edge orborder139.Perforated screens140 and141 are characterized as having a plurality of perforations or holes142. Preferably,perforated screens140 and141 are fabricated to have a contour or shape which corresponds to the expected size and shape of the cardiac tissue to be stabilized. For example,perforated screen140 and141 may have a radius, R, which may be constant or variable.
• As front surfaces144 ofperforated screens140 and141 are urged against the surface of the heart (or other tissue structure), the heart begins to contactfront surface144 around eachperforation142 and thus sealingly covering eachperforation142. As eachperforation142 is covered in this manner, the relatively small portion of tissue residing over eachperforation142 is subjected to the vacuum existing withinhollow interior132 and is accordingly sucked against, and even slightly into,perforation142.
• Because the total vacuum or suction force applied to the tissue is a function of the total tissue area exposed to vacuum, it is desirable forscreens141 and142 to have the aggregate area of all the perforations as great as possible and still maintain the required structural integrity. In a preferred embodiment, the unperforated material between adjacent perforations is between about 0.015 inches (0.38 mm) and about 0.025 inches (0.635 mm) at its smallest point, most preferably about 0.02 inches (0.51 mm), and the diameter of the perforations are from about 0.06 inches (1.524 mm) to about 0.09 inches (2.286 mm).
• A particularly advantageous configuration offront surface144 includes a plurality of projections or protrusions disposed at a number of locations between the holes or perforations.FIGS. 8A and 8B illustrate aperforated member400 having afront contact surface410 which has a number of perforations or holes415. The unperforated material ofmember400 has a plurality ofprojections420 extending outwardly fromcontact surface410. In a preferred embodiment, a plurality of projections are generally equally spaced around eachperforation415. The projections may be formed, for example, by chemical machining or etching.Projections420 operate to more aggressively bite or engagetissue structure425 as it is urged intoperforation415 by operation of an applied vacuum.
• In the embodiments shown inFIGS. 2 and 3, the outermost extending surface ofborder139 is generally even or flush withfront surface144 ofperforated screens140 and141. To maximize the total area of tissue exposed to vacuum, it may be desirable to have a raised border or perimeter which exposes and subjects all the tissue within its boundary to the negative pressure supplied through the interior of the stabilizer feet.FIG. 5 illustratestissue stabilizer200 having aperimeter sealing member215 disposed at the bottom of eachstabilizer foot205 and210.Perforated screens140 and141 are recessed fromperimeter sealing member215.
• Whenperimeter sealing member215 makes contact with the surface of the heart around substantially its entire perimeter, the portion of the heart tissue within the perimeter is subjected to the negative pressure existing within the hollow interior ofstabilizer feet205 and210 and is urged into engagement withstabilizer feet205 and210. The negative or vacuum pressure may be sufficient to displace the portion heart tissue within the vacuum chamber created byperimeter sealing member215 into forced contact withperforated screens140 and141. To further increase traction, perforated screens may optionally have projections as described above.
• An exploded view oftissue stabilizer200 is shown inFIG. 6.Front manifold portion122 has first andsecond bores222 and223 for receiving tubular members orfittings208 associated withstabilizer feet205 and210, respectivelyFittings208 are preferably integrally molded features ofstabilizer feet205 and210, but could alternatively be separate fittings secured to the stabilizer feet by way of, for example, a bonded, welded, or threaded connection.Fittings208 have aflange212 for retaining and compressing O-ring202 within the seal cavity (not visible in this view) and groove214 for receiving a external retaining ring, preferably of the spring type, e-type or the like.Fittings208 preferably have a vacuum inlet opening220 for communicating the negative pressure withinmanifold base120 to the hollow interior region withinstabilizer feet205 and210.
• The multifunctional components oftissue stabilizer200 allow for simple and convenient assembly.Stabilizer foot205 may be assembled tofront manifold portion222 by installing O-ring202 overfitting208 and then installing fitting208 throughbore222. Fitting208 andstabilizer foot205 is secured in place by securing anexternal retaining ring218, into place withingroove214. The same procedure is then used to installstabilizer foot210 tomanifold portion222.Post support member155 is placed in the proper location between or within front andrear manifold portion122 or124 as the two manifold portions are brought together in the presence of an appropriate bonding agent or adhesive to make the assembly leak-free, air-tight, and permanent.Perforated screens140 and141 may be secured tostabilizer feet205 and210 at any convenient time before or after the assembly procedure just described.
• Tissue stabilizer300, shown in exploded view inFIG. 7, allowsstabilizer feet305 and310 to be assembled tofront manifold portion122 using a simple snap-fit construction instead of an external retaining ring. In this variation, the fitting portions ofstabilizer feet305 and310 include aseal flange310, anuninterrupted base portion304 and a number offlexures302 having raised end features303.Flexures302 allow raisedfeatures303 to flex inwardly so that they fit throughbore222 and223 and then flex outwardly as they exit bores222 and223, thus becoming locked in place.
• Tissue stabilizer300 may be assembled using the same basic procedure as described above with reference totissue stabilizer200. In addition, however, because there is no retaining feature to be installed to the fitting portion after placement throughbores222 and/or223, the front and rearmanifold portions122 and124 can be fully assembled and leak tested (if desired) beforestabilizer feet305 and310 are installed. Thus, postsupport member155 is positioned in place in or between front and rearmanifold portions122 and124 as the two manifold portions are brought together in the presence of an appropriate bonding agent or adhesive to secure the manifold base assembly together. An O-ring202 is then placed overuninterrupted portion304adjacent flange310 and raisedfeatures303 onflexures302 are urged throughbore222 or223 until it exits the bore and snaps open and into place, thus fixingstabilizer foot305 or310 to the assembled manifold base.
• Tissue stabilizer300 shows a variation in which astabilizer shaft307 is pre-installed onball135.Stabilizer shaft307 has asocket housing306 which is permanently operably attached toball135. Theball135 and post130 is dropped intohousing306 from a distal direction prior to fixingshaft307 thereto.Post support member155 is then fixed to the proximal end ofpost130, rendering the assembly essentially inseparable. This eliminates any possibility of accidental separation of the stabilizer foot from the stabilizer shaft.
• To gain the advantage of stabilizer feet having different constructions for different procedures or patients, the foregoing design allows the desired stabilizer feet to simply be snapped into place withinbores222 and223, for example, after a clinical determination has been made regarding what size, type, etc. of stabilizer feet will be presently required. Once snapped into place,stabilizer feet305 and310 may be rotated to obtain the desired orientation of each foot to provide maximum stabilization based on the clinical situation presented by an individual patient.
• Stabilizer feet305 and310, or any of the other stabilizer feet described herein, may be provided with additional features to facilitate adjustment ofstabilizer feet305 and310 after engagement with the tissue to be stabilized. The features may be any holes, lever, protrusion, projection, or other suitable feature that allows the stabilizer feet to be easily manipulated during use. Since it is desirable for the device to have an unobstructingly low-profile, especially in the area of the stabilizer feet, the adjustment features are preferably one or moreblind holes308 adapted to receive a blunt instrument for manipulating the orientation ofstabilizer feet305 and310. Alternatively, a hex or nut-shaped feature could be added to each stabilizer foot distal of the seal flange for use with an appropriately sized wrench or the like to rotate the stabilizer feet.
• Perimeter sealing member215 may have a variety of constructions. Sealingmember215 may simply be an integral extension of the stabilizer foot material. In that instance, sealingmember215 will typically be a relatively hard polymer or plastic material. Sealingmember215 may also be a relatively soft elastomer which is attached to or over-molded onstabilizer feet205 and210. Sealingmember215 may also be constructed of a compressible foam material, preferably a closed cell foam. The elastomer or foam materials will preferably compress, deflect or otherwise yield somewhat as the stabilizer feet become engaged with the irregular surface of the heart When sealingmember215 is constructed of an elastomer or foam material, it will preferably have a durometer hardness in the range from about 35 Shore-A to about 100 Shore-A depending on the geometrical configuration of sealingmember215.
• In a preferred embodiment, the perimeter seal has a variable thickness around its perimeter to provide a more reliable seal against the curvature of the surface of the heart, especially when the heart continues to beat during the procedure.FIGS. 9A and 9B show a portion of astabilizer foot430 having aperimeter seal440 with a variable height or thickness around its perimeter. Similar to the previously discussed configurations,stabilizer foot430 has ahollow interior449 to which a negative pressure is communicated.Perforated screen435 has a plurality of holes orperforations437 and is mounted in position onstep feature447 withinstabilizer foot430.Perimeter seal440 is mounted at or near the bottom ofstabilizer foot430, and is preferably retained within a groove orstep448.
• The height thatperimeter seal440 extends from the bottom ofstabilizer foot430, typically varies at different locations around the perimeter ofperimeter seal440. For example, thetip height441 andrear height443 is generally greater thanmidpoint height442 along either side of the stabilizer foot. In addition,height446 ofperimeter seal440 along the inside ofstabilizer foot430, that is the side closest to the target artery, is generally less that theoutside height444 at a corresponding location along thestabilizer foot430.
• The variable height results in a contoured shape ofperimeter seal440 which tends to remain sealed against the heart when the heart expands and contracts as it beats to pump blood. In a preferredembodiment perimeter seal440 is made from an elastomer, a closed-cell foam, or other flexible or compressible material to further optimize the ability of stabilizer foot to maintain its seal on the tissue to be stabilized. If the seal is broken or otherwise compromised, the stabilizer foot may disengage from the surface of the heart, adversely affecting stabilization.Seal440 may be fixed to the stabilizer foot using an adhesive or bonding agent or may be made integral with the stabilizer foot using an injection over-molding process whereinseal440 is molded over the stabilizer foot.
• Another seal variation is illustrated with reference tostabilizer foot450, a portion of which is shown inFIG. 10.Stabilizer foot450 again has ahollow interior449 and aperforated screen435 having perforations or holes437. In this variation,stabilizer foot450 has aflexible seal455 having first andsecond legs458 and459 disposed in an angular relationship which operates as a highly flexible joint allowingperimeter edge456 to move relatively freely towards and away from the bottom ofstabilizer foot450 as required to effectuate a reliable seal against the surface of the tissue to be stabilized. For example, if the tissue under vacuum engagement withstabilizer foot450 contracts and moves away from the tip ofstabilizer foot450,flexible seal455 can easily follow the movement to a new extended position4551 without the seal being broken.
• Flexible seal455 is preferably made from a medical grade elastomeric material such as silicone, urethane rubber, neoprene, nitrile rubber, hytrel, kraton, or other suitable material.Flexible seal455 may be separately formed and later attached tostabilizer foot450 or may be integrally over-molded ontostabilizer foot450. For secure attachment tostabilizer foot450,flexible seal455 may optionally be provided withseal base portion457.
• If greater extension of the flexible seal's perimeter sealing edge away from the stabilizer foot is required, a seal having a greater number of flexible legs in a bellows or accordion type arrangement is employed. Referring toFIG. 11,stabilizer foot460 hasflexible seal465 having continuously connected alternating flexible legs in the form of a bellows.Flexible seal465 may include a base467 to facilitate attachment to the bottom ofstabilizer foot460 and has aperimeter edge466 to effectuate a reliable seal against the surface of the tissue to be stabilized. This type of seal generally compresses to a relatively solid, stable structure as the stabilizer foot is urged against the surface of the tissue, has a the ability to follow moving tissue over a relatively long travel if required, and yet occupies only a very small amount of space around the perimeter of the stabilizer foot.
• Another flexible seal arrangement is illustrated inFIGS. 12-13B with reference totissue stabilizer470.Tissue stabilizer470 has amanifold base473 comprised of frontmanifold portion472,rear manifold portion474 havingvacuum inlet tube471, andball476 to which a stabilizing shaft may be attached.Stabilizer feet475 and480 may be attached tostabilizer base473 in any of the ways discussed above. Most preferably,stabilizer feet475 and480 have afitting portion485 which includes an uninterruptedcylindrical portion486, one ormore flexures487 each having raisedfeatures488 that provide a positive snap-fit joint in cooperation within cylindrical bores formed infront manifold portion472 as described in detail above. Preferably, fitting485 has aflange479 for retaining and compressing a shaft seal or the like.
• Stabilizer feet475 and480 have attached theretoflexible seals482 and477, respectively.Flexible seals477 and482 may extend completely around the perimeter ofstabilizer feet480 and475. More preferably,stabilizer feet475 and480 have at least one portion of its perimeter having a flexible seal and at least one portion without a flexible seal. According to this variation of the present invention, thestabilizer feet475 and480 are primarily sealed against the target tissue by operation of theirown perimeter edge481.Flexible seals482 and477 are provided generally outside ofperimeter edge481 to provide a form of secondary or back-up seal in the event the seal atperimeter edge481 becomes compromised as a result of misalignment or movement of the tissue.Flexible seals477 and482 are preferably sufficiently flexible to remain in contact with the movements of the beating heart so that when the seal breaks along 481 perimeter edge the vacuum loss is contained withinflexible seal482 or477. This containment typically allows the comprised area ofperimeter edge481 to become re-engaged against the tissue without significant vacuum loss.
• After engagement and stabilization of the beating heart, the vacuum seal formed at the perimeter edge of the stabilizer feet may be most likely to break at the tip region or along the outside edge of the stabilizer foot as the heart contracts away from the site of stabilization. In such circumstances,flexible seals477 and482 need only be associated with these problem areas, leaving insideperimeter portion478 and the space betweenstabilizer feet475 and480 open to avoid obstructing the surgical field of the anastomosis.Flexible seals477 and482 have a contouredouter periphery483 which may be a relatively large distance away from the outer extents of thestabilizer feet475 and480 and may include extendedtip portions484.Flexible seals477 and482 preferably have a top portion for attaching to the stabilizer feet about theperimeter edge481.Flexible seals477 and482 may be fixed in place using an adhesive or bonding agent or may be integrally over-molded as part ofstabilizer feet475 and480.
• Another way to prevent a complete loss of engagement and stabilization of the target tissue due to a compromised perimeter seal resulting from misalignment of the stabilizer feet or movement of the target tissue to be stabilized, is to partition the vacuum chamber within the stabilizer feet into a plurality of chambers connected to the vacuum source through only a small aperture. In that way, a vacuum leak at a single location will is result in a reduced ability to maintain engagement of that partitioned section only and will not immediately compromise the engagement of the entire stabilizer foot. Of course, it may be desirable to combine any one of the flexible seals described above with partitioning to further increase the reliability of the stabilizer foot seal against the tissue structure to be stabilized.
• A tissue stabilizer embodiment having stabilizer feet with a partitioned vacuum chamber is illustrated inFIGS. 14 and 15.Tissue stabilizer500 has amanifold base501, preferably having front and rearmanifold portions504 and502, to which first andsecond stabilizer feet505 and506 are attached. First andsecond stabilizer feet505 and506 have perimeter seal edges507 and508 which generally define the extents of the vacuum chambers for each stabilizer foot. One ormore partitions509, each having a sealingedge511, are provided to dividestabilizer feet505 and506 into two or more vacuum subchambers. By way of example only,stabilizer feet505 and506 havepartitions509 which divide the vacuum space into first, second, third, andfourth vacuum subchambers517,518,549, and520, respectively.
• Vacuum feed tube510 is provided along the interior ofstabilizer feet505 and506 to communicate the negative pressure from within the manifold base to each ofsubchambers517,518,519, and520.Vacuum feed tube510 preferably has a side opening oraperture512 within each ofsubchambers517,518, and519.Vacuum feed tube510 may have an end opening oraperture513 withinsubchamber520. Theapertures512 and513 facilitate the separate communication of negative pressure to each vacuum subchamber and are preferably sized such that when one subchamber encounters a vacuum leak, the aperture is restricted enough so that the vacuum in the other subchambers can be maintained by the vacuum source.
• Stabilizer feet505 and506 are preferably rotatable with respect tomanifold base501 as discussed at length above. For example,stabilizer feet505 and506 may have afitting portion515 which is preferably cylindrical to cooperate with a mating bore provided inmanifold base501. Fittingportion515 may have aflange514 for retaining a shaft seal and a groove for receiving an external retaining ring to securefitting portion515 withinmanifold base501. The bottom ofstabilizer feet505 and506 may have a contoured shape having a variable or fixed radius, R. A flexible seal may optionally be included along one or all of sealingedges507,508, and511.
• A partitioned vacuum chamber as described above maximizes the area exposed to negative pressure for a particular size of stabilizer foot. That is, the ratio of the surface area exposed to negative pressure divided by the total surface area included with the boundary at the bottom of the stabilizer foot is maximized by the partitioned chamber configuration just described. In another embodiment, although less efficient in that regard, rotatable stabilizer feet can be constructed to have a number of individual vacuum ports or pods.
• FIGS. 16 and 17 illustratestabilizer foot550 having a plurality of individual vacuum ports. By way of example only,stabilizer foot550 has foursuction ports551,552,553, and554 each with adedicated edge seal561. Negative pressure is communicated to each port through openings orapertures560 provided invacuum distribution passage563 which is fluid communication withvacuum inlet562 which in turn is placed in fluid communication with the negative pressure within a manifold base assembly having a construction as described above.Stabilizer foot550 may be mounted for rotation within a cooperating bore of an appropriate manifold base by way of cylindricalfitting portion556 which may include aseal flange555 and groove557 for receiving an external retaining ring to securefitting portion556 in place.
• FIGS. 18 and 19 show a variation of a stabilizer foot having a plurality of individual ports.Stabilizer foot575 again has afitting portion599 having aseal flange598 for retaining and compressing an appropriate shaft seal to provide the desired dynamic seal asstabilizer foot575 is rotated aboutfitting portion599. To facilitate even greater adjustment of the shape and orientation ofstabilizer foot575 has afirst foot portion580 with at least one vacuum port and asecond foot portion585 with at least one vacuum port which are adjustable relative to one another, preferably by way of one or more malleable joints or links.
• In a preferred embodiment,first foot portion580 has a plurality ofseparate vacuum ports581 each with aperimeter seal582. Preferably,first foot portion580 has threevacuum ports581 each supplied with negative pressure throughapertures578 in vacuum distribution channel orpassage593.Second foot portion585 has at least onevacuum port583 havingperimeter seal584 andaperture577 in fluid communication withvacuum passage592.First foot portion580 andsecond foot portion585 are preferably connected to each other bymalleable tube590, which has a lumen orpassage591 therethrough.Malleable tube590 is preferably made of stainless steel, more preferably annealed stainless steel or vacuum annealed stainless steel.
• With this configuration, the vacuum communicated from a manifold base or other vacuum source throughvacuum inlet channel595 is distributed to vacuumports581 and583 throughvacuum distribution channel593 and associatedapertures578, throughmalleable tube passage591, finally tovacuum passage592 and associatedaperture577. The orientation ofsecond foot portion585 and thusvacuum port583 can be adjusted relative tofirst foot portion580 by simple bending it to the desired orientation. This additional adjustment tends to eliminate problems associated with obtaining a reliable seal at the tip of the stabilizer foot as the beating heart contracts away from the stabilizer, yet maintains the reliability of havingports603 molded to a unitary relatively rigid stabilizing structure.
• Malleable tube590 may be secure tofirst foot portion580 andsecond foot portion585 in any convenient manner which provides a permanent and sealed connection. Preferably, the exterior ofmalleable tube590 may be pressed intomating counterbores596 and597 provided in the ends ofVacuum passages593 and592 as shown. A suitable adhesive or bonding agent may additionally be used to sealingly securemalleable tube590 in place. Alternatively,malleable tube590 andcounterbores596 and597 may be threaded together ormalleable tube590 could be insert molded within first andsecond foot portions580 and585.
• FIGS. 20 and 21 illustrate another embodiment of a stabilizer foot having foot portions which are adjustable relative to one another to improve the fit, and accordingly the operating vacuum seal, against the surface of the tissue structure to be stabilized.Stabilizer foot600 has afirst foot portion601 and asecond foot portion602.First foot portion601 has one or more, preferably three,vacuum ports603 andsecond foot portion602 has one ormore vacuum ports608. Each ofvacuum ports603 and608 preferably have a flexible orcompressible perimeter seal604 and609, respectively, preferably made of a medical grade elastomer or foam. Negative pressure is supplied to vacuumports603 and608 through openings orapertures715 and716 which in fluid communication withvacuum passages711 and712. Negative pressure is supplied tovacuum passage711 through inlet channel orpassage710 offitting portion718. Fittingportion718 connected to a vacuum chamber or source within a manifold base or like structure as described above.
• First foot portion601 andsecond foot portion602 are made adjustable relative to each other by providing one or more malleable links spanning between the two portions. In one variation, first and secondmalleable members606 and607 are located off-center withrespect vacuum ports603 and608. The off-center position ofmalleable members606 and607 better protects against excessive torsional loads applied totube605 ifsecond foot portion602 were twisted relative tofirst foot portion601.
• Malleable members606 and607 may be glued or bonded within cavities or bores provided within first andsecond foot portions601 and602 or may be insert molded during fabrication of the foot portions.Tube605 fluidly connectsvacuum passages711 and712. In this case,tube605 may be malleable or may be a flexible tubing material. Preferably,tube605 is assembled withincounterbores713 and714.
• In operation, the tissue stabilizers of the present invention allow the stabilizer feet, and in particular the features which operate to engage the surface of the tissue to be stabilized, to be optimally adjusted to for a specific surgical procedure or to adjust for variations in size and orientation of a patient's anatomy. In addition, the stabilizer feet can be adjusted after engagement to the tissue to be stabilized to produce an improved presentation of the tissue subject to the surgical procedure.
• In a preferred method of operation for a tissue stabilizer having first and second rotatable stabilizer feet connected to a manifold base having a stabilizer shaft attached thereto, one or both of the stabilizer feet are adjusted to the desired orientation relative to the manifold base and each other. Preferably, the orientation of the stabilizer feet are adjusted to account for the size and shape of the tissue to be stabilized, for example a target site on the surface of the heart. If either of the stabilizer feet have an adjustable portion, it may also be adjusted at this time. Next, the tissue stabilizer is brought into engagement with the tissue to be stabilized and the vacuum is applied. The stabilizer shaft is then locked into place to immobilize the tissue stabilizer and the engaged tissue. With the surgical site now relatively motionless, one or both of the stabilizer feet may be rotated relative to the manifold base until the tissue between or adjacent the stabilizer feet obtains the best possible presentation for the procedure to be performed. If there appears to be any discernible vacuum leaks associated with the engagement of the stabilizer feet against the target tissue, the orientation of the stabilizer feet may be further adjusted or, if applicable, the feet portions may be adjusted, to eliminate or minimize vacuum leaks at the interface between the stabilizer feet and the target tissue.
• Although the illustrative stabilizer feet described above have been primarily directed to embodiments configured for connection to a common manifold base, the stabilizer feet of the present invention will operate with equal benefit when connected to any number of alternative structures. For example,FIG. 22 illustratestissue stabilizer725 having a stabilizer foot rotatably connected with respect to a portion of common tubing having a flared end.Tube740 may be a malleable tube, for example made of annealed stainless steel, which may be connected proximally to a manifold (not shown) shared with a second stabilizer foot or may be connected directly to a fixed mount (not shown) to effectuate stabilization.
• In a preferred embodiment,stabilizer foot730 is connected tohousing735 which rotates abouttube740.Tube740 has a flaredend742 as is commonly known in the art. A shaft seal, such as O-ring732, is place overtube740 adjacent flaredend742.Housing735 has afirst bore737 and a secondlarger bore738. First bore737 is larger than the outside diameter oftube740 but preferably smaller than the diameter offlanged end742.Second bore738 is preferably slightly larger thanflanged end742.Tube740 with O-ring732 is assembled throughsecond bore738 until the O-ring is compressed at the distal entrance tofirst bore737. An O-ring cavity736 may be provided if desired. Fittingportion734 is inserted intosecond bore738 and permanently fixed in place preferably using a fluid tight connection such as pipe threads, adhesive, bonding agent, welding, brazing, etc. Withfitting portion734 fixed tohousing735,stabilizer foot730 andhousing735 may be rotated relative totube740 without any appreciable vacuum leakage.Stabilizer foot730 may be of any desirable configuration.
• While certain embodiments are illustrated in the drawings and have just been described herein, it will be apparent to those skilled in the art that many modifications can be made to the embodiments without departing from the inventive concepts described. For purposes of illustration only, the principles of the present invention has been described with reference to stabilizing the heart during a coronary artery bypass procedure but may readily be applied to other types surgical procedures on various types of tissue structures not specifically described. Many other uses are well-known in the art, and the concepts described herein are equally applicable to those other uses. Further, the different components and their equivalents of the various exemplar embodiments described above can be combined to achieve any desirable construction.

Claims (38)

1-42. (canceled)

43. A device for stabilizing tissue within a patient's body, said device comprising:

a base member defining a base vacuum chamber and having a distal surface; and

at least one elongated stabilizer foot extending outwardly from said distal surface of said base member in a first direction and fluidically connected with said base vacuum chamber, said at least one stabilizer foot being rotatable, in its entirety, relative to said base member about an axis of rotation.

44. The device according toclaim 43, wherein said stabilizer foot is connected to said base member through a dynamically sealed rotating connection.

45. The device according toclaim 44, wherein connection allows for rotation of said stabilizer foot without incurring any vacuum loss.

46. The device according toclaim 45, wherein said stabilizer foot may be rotated without incurring any vacuum loss when said stabilizer foot is operably engaged to tissue.

47. The device according toclaim 44, wherein said connection is a dynamic annular or shaft seal that allows for rotation of said stabilizer foot without incurring any vacuum loss.

48. The device according toclaim 43, wherein said axis of rotation is oriented in substantially the same direction as said first direction.

49. The device according toclaim 43, wherein said axis of rotation is oriented at an angle of no more than about 25 degrees to said first direction.

50. The device according toclaim 43, wherein said stabilizer foot comprises features adapted to engage a surface of the tissue, said features approximating the surface, and wherein said axis of rotation is angled with respect to said surface.

51. The device according toclaim 43, wherein said elongated stabilizer foot comprises a hollow chamber extending substantially over the length of said elongated stabilizer foot.

52. The device according toclaim 43, wherein said device comprises two elongated stabilizer feet.

53. The device according toclaim 43, wherein said at least one elongated stabilizer foot comprises a tissue engaging feature with a non-planar perimeter.

54. The device according toclaim 53, wherein said tissue engaging feature has a constant radius of curvature.

55. The device according toclaim 53, wherein said tissue engaging feature has variable radius of curvature.

56. A device for stabilizing tissue within a patient's body, said device comprising:

a base member defining a base vacuum chamber and having a distal surface; and

at least one elongated stabilizer foot comprising a plurality of individual vacuum ports said stabilizer foot extending outwardly from said distal surface of said base member in a first direction and fluidically connected with said base vacuum chamber, said at least one stabilizer foot being rotatable, in its entirety, relative to said base member about an axis of rotation which is oriented in substantially the same direction as said first direction. (page 30 lines 8-10).

57. The device ofclaim 56, wherein said individual vacuum ports independently engage said tissue.

58. The device ofclaim 57, wherein each of said individual vacuum ports has a compressible perimeter seal.

59. The device ofclaim 56, wherein said elongated stabilizer foot comprises a first foot portion comprising at least one vacuum port and a second foot portion comprising at least one vacuum port, wherein said first and said second foot portions are adjustable relative to one another.

60. The device ofclaim 59, wherein said first and said second foot portions are adjustable relative to one another by way of one or more malleable joints.

61. The device ofclaim 59, wherein said first and said second foot portions are rigid.

62. The device ofclaim 56, wherein said elongated stabilizer foot is rotatably mounted on said base member and rotation of said stabilizer foot does not incur any vacuum loss.

63. A device for stabilizing tissue within a patient's body, said device comprising:

a base member; and

an elongated stabilizer foot extending outwardly from said base member in a first direction and fluidically connected with said base member, said foot having non-planar tissue-engaging features, said foot being rotatable, in its entirety, relative to said base member, about an axis of rotation.

64. The device ofclaim 63, wherein said axis of rotation is oriented relative to a best-fit plane approximating the tissue engaging features.

65. The device ofclaim 63, wherein said axis of rotation is oriented relative to a central tangent plane of the tissue engaging features.

66. The device ofclaim 63, wherein said base is a common tube.

67. The device ofclaim 66, wherein said device further comprises a housing connected to said foot which rotates around said base.

68. The device ofclaim 63, wherein said tube is flanged, and said tube is connected to said base member using a shaft seal.

69. The device ofclaim 68, wherein said shaft seal is an O-ring.

70. The device ofclaim 63, wherein said elongated stabilizer foot has an elongated perimeter adapted to contact the tissue.

71. A device for stabilizing tissue within a patient's body, said device comprising:

a base member; and

an elongated stabilizer foot extending outwardly from said base member in a first direction and fluidically connected with said base member, said foot having non-planar tissue-engaging features comprising a perimeter seal having a variable height around its perimeter, said foot being rotatable, in its entirety, relative to said base member, about an axis of rotation.

72. The device ofclaim 71, wherein said stabilizer foot further comprises a perforated screen recessed from the perimeter seal.

73. The device ofclaim 71, wherein said perimeter seal is retained within a groove in the stabilizer foot.

74. The device ofclaim 71, wherein said perimeter seal is higher at a front tip of said stabilizer foot as compared to a midpoint of said stabilizer foot.

75. The device ofclaim 71, wherein said perimeter seal is higher at a rear end of said stabilizer foot as compared to a midpoint of said stabilizer foot.

76. The device ofclaim 71, wherein said height varies to form a contoured shape adapted to remain sealed against a tissue surface.

77. A device for stabilizing tissue within a patient's body, said device comprising:

a base member; and

an elongated stabilizer foot extending outwardly from said base member in a first direction and fluidically connected with said base member, said foot having a non-planar tissue-engaging feature comprising a perimeter seal having a variable height around its perimeter, said foot being rotatable, in its entirety, relative to said base member, about an axis of rotation;

wherein said perimeter seal is a flexible seal having first and second legs disposed in an angular relationship.

78. The device ofclaim 77, wherein said perimeter seal comprises a plurality of legs angularly disposed in a bellows arrangement.

79. The device ofclaim 77, wherein said perimeter seal is made from an elastomeric material selected from the group consisting of: silicone, urethane rubber, neoprene, nitrile rubber, hytrel, and kraton.

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