Vascular clamps and surgical retractors with directional filaments for tissue engagement

[0002] This application is a continuation of U.S. application Ser. No. 09/337,115 filed on Jun. 21, 1999, which is a continuation-in-part of U.S. application Ser. No. 08/993,076 filed Dec. 18, 1997 now U.S. Pat. No. 6,007,552, which is incorporated herein by reference in its entirety.

[0003] 1. Field of the Invention

[0004] The present invention relates generally to surgical instruments for occluding a vessel or other tubular structure, for grasping and retaining other body tissue, for retracting tissue at a surgical incision site, or for stabilizing tissue or bodily organs within a surgical incision site. More particularly, the invention relates to surgical instruments such as surgical clamps, surgical retractors or surgical stabilizers that include resilient filaments that abut against a vessel, tissue or organ to resist movement of the vessel, tissue or organ relative to the instrument. The invention further relates to methods of manufacturing clamp pads or members for attachment to such instruments that include such resilient filaments.

[0005] 2. Description of the Related Art

[0006] Instruments for occluding blood vessels during surgery, such as conventional metal or rigid surgical clamps or clips, are well known. However, such instruments are known to cause trauma to the clamped vessel at the clamping site. A number of atraumatic instruments have been developed for reducing or eliminating the trauma to a vessel during occlusion of the vessel. U.S. Pat. No. 3,993,076 to Fogarty, et al. describes a device whereby a vessel is occluded by using a resilient tape to press a vessel against a resilient pad. However, this device suffers from the disadvantage that it slips easily. For example, the pulsations of an occluded artery can tend to force the device off of its clamped position on the occluded artery. Conventional surgical clamps have also been adapted to include jaw surfaces containing resilient members or pads. These devices likewise are prone to slipping off of the clamped vessel. This can be especially problematic in situations where, due to obstructions, a vessel has been clamped with only the distal tips of the clamp jaws. In such situations, the vessel can be especially prone to slipping in the direction of the distal tips.

[0007] Other attempts have been made to atraumatically occlude a vessel in a secure fashion. U.S. Pat. No. 3,746,002 to Haller describes a vascular clamp with resilient gripping members located on the jaws. A plurality of pin members are embedded within the gripping members, the pin members of a length such that when a vessel is clamped between the members, the resilient material deflects to accommodate the vessel, exposing the pin members which grippingly engage the outer layer of the vessel, thus securing the vessel to the gripping member. While the Haller device is less traumatic to a vessel than other occlusion devices, it nevertheless has the disadvantage of traumatizing the outer layer of the vessel.

[0008] U.S. Pat. No. 4,821,719 to Fogarty describes a vascular clamp device containing resilient pads with Velcro-like hooks. The hooks interact with the external adventitial layer of the vessel forming a cohesive-adhesive relationship with the vessel similar to the bonding of Velcro materials. While this device offers a less traumatic way to occlude a vessel, the cohesive-adhesive nature of the bond can result in the removal of some of the adventitial layer of the vessel when disengaging the device.

[0009] There is thus a need for a surgical clamp which atraumatically occludes vessels while avoiding the disadvantages previously associated with existing surgical clamps or occlusion devices.

[0010] Likewise, conventional tissue retractors are well known which retract tissue at a surgical incision site to provide a surgeon visual and mechanical access to the interior of a patient's body. These tissue retractors employ rigid gripping members, usually of metal, to grip, retract, and retain all forms of body tissue, e.g., bone, skin, fat, or muscle, at the incision site. The disadvantages of such retractors are two-fold. First, the rigid gripping members, due to their rigidity, cause trauma to the retained tissues. Second, the gripping members are generally prone to slippage, both laterally, along the sides of the incision, and upwardly out of the incision and away from the patient's body.

[0011] Thus, there is also a need for a surgical retractor that atraumatically, yet securely, retracts and retains tissue at a surgical incision site.

[0012] Other surgical instruments or devices are known that provide for mechanical immobilization and stabilization of tissue or organs within a surgical incision site. These instruments or devices, known as stabilizers, will immobilize, stabilize, or otherwise restrain tissue or organs by exerting pressure against a tissue or organ to hold the tissue or organ in place, aiding a surgeon performing operations on the tissue or organ. Such stabilizers have particular use in minimally invasive coronary surgery procedures. For example, coronary artery stabilizers have been used to immobilize a beating heart in order to perform coronary grafting. These stabilizers achieve immobilization largely by local myocardial compression from direct pressure applied by the stabilizer on either side of the grafted artery. These stabilizers come in a variety of shapes, including open foot-shaped devices, and rigid circle or rectangular shapes, and may be either hand held, or attached to an incisional retractor located at the incision site. Another such stabilizer device consists of a system having two fixed handles having suction cups that are positioned on either side of the vessel.

[0013] Given the amount of pressure transferred to the myocardium during the use of these stabilizers, there is a danger that the contact surfaces of these stabilizer devices will traumatize the myocardial tissue. In addition, the forces exerted by the immobilized but still beating heart can lead to a shift in alignment of the stabilizer, which can disrupt the grafting procedure. Thus, there is a need for stabilizers that atraumatically immobilize a tissue or body organ, such as the heart, and yet at the same time provide improved traction to maintain the position of the immobilized tissue or organ.

[0014] It is an object of the present invention to provide surgical instruments, including surgical clamps or other occlusion devices, surgical retractors, or surgical stabilizers having gripping surfaces and an array of resilient filaments extending at acute angles relative to the surface for engagement with vessels, tissue, or organs. The filaments terminate in free distal ends that abut against the engaged vessel, tissue or organ to resist and restrict movement of the engaged vessel, tissue or organ in a direction opposed to the orientation of the filaments. The filaments themselves can also be resiliently flexible so as to cushion the engaged vessel, tissue or organ.

[0015] In the case of a surgical clamp according to the present invention, the filaments are located on opposing jaws of a surgical clamp. When the jaws are moved toward one another to engage a vessel, some of the filaments, based on their angle of orientation in relation to the vessel, will abut against the vessel and impart a resistive force against the vessel along the direction of the filament. When the jaws of the surgical clamp are partially or fully engaged with the vessel, filaments of the lower jaw push or lever the vessel upward toward the upper jaw, while at the same time filaments of the upper jaw push or lever the vessel downward toward the lower jaw. This levering action of the filaments secures against movement of the vessel in a direction generally opposed to the orientation of particular filaments.

[0016] In one embodiment of the invention, the filaments can extend directly from the surface, which itself can be resiliently flexible. In this embodiment, when the jaws are moved toward one another to engage a vessel, some of the filaments, based on their angle of orientation in relation to the vessel, will be pressed flat against the surface which will itself deflect to accommodate the vessel in atraumatic fashion. In an alternative embodiment, the filaments can extend from along the sides of the resilient surface and the distal ends of the filaments can terminate at positions even with, above, or below the level of the surface. In this embodiment, the surface can deflect to atraumatically engage the vessel while the filaments are likewise engaging the vessel and resisting movement of the vessel in a direction opposed to the orientation of the filaments. Where the distal ends of the filaments terminate at a position below the level of the surface, the surface will deflect to a position where both the surface and the filaments will engage the vessel.

[0017] In another embodiment of the invention, the filaments can be oriented as discussed above to resist movement of the vessel in the direction of the distal ends of the surgical clamp jaws. Such an orientation is especially advantageous where, due to obstructions, a surgeon can only access and clamp a vessel with the distal tips of the surgical clamp jaws. With a conventional clamp, the vessel can slip from the clamp in the direction of the distal tips. In the above embodiment of the present invention, however, slippage of the vessel will favor the direction back toward the proximal ends of the surgical clamp jaws, thereby retaining the vessel in a clamped condition.

[0018] In another embodiment of the invention, the filaments of the upper and lower jaws of the surgical clamp are oriented to resist movement of a clamped vessel towards either the distal or the proximal ends of the jaws. The filaments can also be oriented to resist movement of a clamped vessel in a direction perpendicular to the jaws.

[0019] A surgical retractor according to the present invention likewise uses resilient surfaces with resilient filaments that engage and retract tissue. When the resilient member, or base member, containing the resilient filaments engages tissue at an incision site, the tips of some of the filaments, again based on the angle of orientation of these filaments in relation to the tissue being retracted, will abut against the tissue and impart a resistive force against the tissue along the direction of the filament. In one embodiment of the invention, the filaments can be oriented to resist movement of the retracted tissue relative to the base member in a lateral direction along the sides of the incision and in an upwardly direction away from the patient's body.

[0020] A surgical stabilizer according to the present invention also includes surfaces having resilient filaments that engage and restrain tissue or organs. When the resilient filaments engage the target tissue or organ, the tips of some of the filaments, again based on the angle of orientation of these filaments in relation to the tissue or organ being restrained, will abut against the tissue or organ and impart a resistive force against the tissue or organ along the direction of the filament. In one embodiment of the invention, the stabilizer can have one or more stabilizing members or arms that engage the target tissue or organ. The resilient filaments of each engaging arm can be oriented to resist relative movement of the restrained tissue or organ along the arm length and/or transverse to the arm length.

[0021] It is a further object of the present invention to provide attachable pads or members for a surgical clamp or other occlusion device, surgical retractor, or surgical stabilizer that contain gripping surfaces and arrays of filaments extending at acute angles relative to the surfaces for engagement with vessels or tissue. Again, these filaments are such that when the particular device is engaged with a vessel or other tissue, the filaments abut against the vessel or tissue to resist and restrict movement of the vessel or tissue in a direction opposed to the orientation of the filaments. The filaments can extend directly from the surface of the pad or can extend from along the sides of pad. For pads having filaments extending directly from the pad surface, preferably the pad will include a resilient or elastomeric cushion having portions of the filaments embedded in the cushion itself. Optimally, the filaments are resiliently deflectable and the cushion will be softer and more easily deflected than the filaments. The characteristics of the cushion and the embedded filaments are such that the cushion and filaments work together to achieve a synergistic effect. The portion of the cushion containing the embedded filaments forms a clamping region of the cushion. The embedded filaments provide structural support to the clamping region, by reinforcing and stabilizing the region against excessive deformation, especially lateral deformation, when the pad is under a clamping load. The clamping region in turn stabilizes and orients the filaments at the desired angles relative to the pad surface to provide directional resistance against movement of engaged vessels or tissue. The clamping region performs this orientation function prior to and during the application of a clamping load to the pad. When a load is applied to the pad, the filaments and the cushion are deflected, but the clamping region stabilizes the filaments against excessive deformation and maintains the desired orientation of the filaments. The clamping region continues to perform this function as the load is released from the pad and the deflected filaments and cushion return to their original pre-loaded positions.

[0022] Methods of manufacturing the attachable pads or members of the present invention are also provided. According to one method, a tubular or cylindrical sleeve of woven resilient filaments is provided and a pad with a gripping surface is extended through the sleeve. The sleeve is secured to the pad opposite the gripping surface and the sleeve is then cut longitudinally along the gripping surface, releasing the resilient filaments to extend at acute angles relative to the gripping surface.

[0023] FIG. 1 is a perspective view of a surgical clamp according to the present invention in a position to engage a vessel;

[0024] FIG. 2 is a perspective view of the surgical clamp of FIG. 1 engaged with and occluding a vessel;

[0025] FIG. 3 is a perspective view of a surgical clamp pad capable of attachment to the jaw of a surgical clamp, with a surface containing resilient filaments according to the present invention;

[0026] FIG. 4 is an enlarged perspective view of the surgical clamp pad of FIG. 3, with parts broken away;

[0027] FIG. 5 is an end view of the surgical clamp pad of FIG. 3;

[0028] FIG. 6 is a side view of opposed jaws of a surgical clamp with attached clamp pads of FIG. 3 which include opposed surfaces containing resilient filaments, positioned to engage a vessel;

[0029] FIG. 7 is a side view according to FIG. 6 where the opposed surfaces containing resilient filaments have engaged the vessel, and the vessel is partially occluded;

[0030] FIG. 8 is a side view according to FIG. 7 where the opposed surfaces containing resilient filaments have fully engaged the vessel and the vessel is occluded;

[0031] FIG. 9A is an enlarged side view of FIG. 8 showing the resilient filaments of the lower opposed surface engaged with the vessel in greater detail;

[0032] FIG. 9B is an enlarged side view similar to FIG. 9A showing the resilient filaments of the upper opposed surface in a different orientation;

[0033] FIG. 10 is a top view of a pad constructed according to the present invention having a different arrangement of resilient filaments, with part of the pad broken away;

[0034] FIG. 11 is a side view of the FIG. 10 pad;

[0035] FIG. 12 is an end view of the FIG. 10 pad;

[0036] FIG. 13 is top view similar to FIG. 10 of a pad constructed according to the present invention having yet another arrangement of resilient filaments, with part of the pad broken away;

[0037] FIG. 14 is a side view of the FIG. 13 pad;

[0038] FIG. 15 is an end view of the FIG. 13 pad;

[0039] FIG. 16 is a perspective view of a surgical clamp pad according to the present invention with resilient filaments extending from along the sides of the pad;

[0040] FIG. 17 is a side view of the FIG. 16 pad;

[0041] FIG. 18A is a cross-sectional view of the pad shown in FIG. 17 taken along line 18A—18A of FIG. 17;

[0042] FIGS. 18B-18D are cross-sectional views of pads according to the present invention showing different configurations of resilient filaments;

[0043] FIG. 19 is a side view of opposed jaws of a surgical clamp with attached clamp pads of FIG. 16 which include opposed surfaces and resilient filaments, and where the surfaces and filaments have engaged the vessel and the vessel is partially occluded;

[0044] FIG. 20 is a perspective view of a surgical clamp pad with resilient filaments according to the present invention;

[0045] FIG. 21 is a side view of the FIG. 20 pad;

[0046] FIG. 22 is a cross-sectional view of the pad shown in FIG. 21 taken along line 22—22 of FIG. 21;

[0047] FIG. 23 is a side view of opposed jaws of a surgical clamp with attached clamp pads of FIG. 20 which include opposed surfaces and resilient filaments, and where the surfaces and filaments have engaged the vessel and the vessel is partially occluded;

[0048] FIG. 24 is an exploded perspective view illustrating resilient filaments according to the present invention secured along individual spines;

[0049] FIG. 25 is a perspective view illustrating the resilient filaments and spines of FIG. 24 in an assembled nested condition;

[0050] FIG. 26 is a perspective view illustrating the assembled resilient filaments and spines of FIG. 25 embedded in a resilient cushion;

[0051] FIG. 27 is a top view of a pad constructed according to the present invention having yet another arrangement of resilient filaments, with parts of the pad broken away;

[0052] FIG. 28 is a perspective view of the pad shown in FIG. 27;

[0053] FIG. 29 is a perspective view of a surgical retractor according to the present invention positioned above a surgical incision site;

[0054] FIG. 30 is a side view of a base member of the surgical retractor shown in FIG. 29;

[0055] FIG. 31 is a cross-sectional view of the base member shown in FIG. 30, taken on line 31—31 of FIG. 30;

[0056] FIGS. 32A-32E are side views illustrating different configurations of resilient filaments which may be used in the present invention;

[0057] FIGS. 33A-33E are end views of the resilient filaments of FIGS. 32A-32E, respectively.

[0058] FIG. 34A is a perspective view illustrating a tubular sleeve of resilient filaments and a pad prior to assembly according to the present invention;

[0059] FIG. 34B is an end view of the sleeve and pad of FIG. 34A;

[0060] FIG. 35A is a perspective view of the sleeve and pad of FIG. 34A with the sleeve in a tightened condition against the pad;

[0061] FIG. 35B is a cross-sectional view of the sleeve and pad shown in FIG. 35A, taken on line 35B—35B of FIG. 35A;

[0062] FIG. 36A is a perspective view of the sleeve and pad assembly of FIG. 35A, secured to a base member;

[0063] FIG. 36B is a cross-sectional view of the assembly of FIG. 36A, taken on line 36B—36B of FIG. 36A;

[0064] FIG. 37 is a perspective view of the assembly of FIG. 36A showing the removal of excess portions of the sleeve;

[0065] FIG. 38A is a perspective view of the assembly of FIG. 37 showing the sleeve being cut longitudinally along the pad;

[0066] FIG. 38B is a perspective view of the assembly of FIG. 38A showing the sleeve completely cut longitudinally along the pad and the resilient filaments of the sleeve extending upward from the pad surface, forming a pad having resilient filaments according to the present invention;

[0067] FIG. 38C is an end view of the pad shown in FIG. 38B;

[0068] FIG. 38D is an end view of a pad according to the present invention showing a different configuration of resilient filaments;

[0069] FIG. 39 is a perspective view of another surgical retractor according to the present invention;

[0070] FIG. 40 is an enlarged side view of the surgical retractor of FIG. 39 with parts broken away;

[0071] FIG. 41 is a perspective view of yet another surgical retractor according to the present invention;

[0072] FIG. 42 is an enlarged side view of the surgical retractor of FIG. 41 with parts broken away;

[0073] FIG. 43 is a perspective view of a surgical stabilizer according to the present invention;

[0074] FIG. 44 is an enlarged side view of the surgical stabilizer of FIG. 43 with parts broken away; and

[0075] FIG. 45 is a perspective view of the surgical stabilizer of FIG. 43 secured to a rib spreader and positioned within an incision site where the stabilizer has engaged and is stabilizing a heart.

[0076] FIG. 1 is a surgical clamp comprising a pair of opposed jaws 22 and 24 and handles 10 and 12 hinged together by pin 14. The handles 10 and 12 terminate in finger and thumb rings 2 and 4 that provide for manual operation of the jaws by a surgeon. Interlocking pawl 6 and ratchet teeth 8 are provided on handles 10 and 12, respectively, to secure jaws 22 and 24 in an adjusted clamped position with a vessel V. In FIG. 1, opposed jaws 22 and 24 are positioned to engage vessel V. The opposed jaws 22 and 24 include opposed pads 32, 32 attached to members 30, 30, which are in turn detachably secured to opposed jaws 22 and 24.

[0077] FIG. 2 shows the surgical clamp with opposed jaws 22 and 24 in an adjusted clamped position. The opposed pads 32,32 clamp vessel V, thereby causing occlusion of vessel V. Interlocking ratchet teeth 8 are engaged with interlocking pawl 6 to secure the opposed jaws in the clamped position.

[0078] An embodiment of the pad 32 and attaching member 30, is depicted in FIGS. 3 and 4. The pad 32 includes resilient filaments 40 for resisting movement of an occluded vessel relative to the pad 32. As FIGS. 3 and 4 depict, the resilient filaments 40 extend from the pad 32 at acute angles relative to the surface of the pad 32. Any acute angle relative to the surface will operate to resist relative movement of an occluded vessel. The preferred angle is 45 degrees relative to the surface.

[0079] The resilient filaments 40 are comprised of a durable yet flexible material, such as nylon or polyester or polypropylene. The filaments cannot be so rigid that they puncture the occluded vessel, but they must be of a strength and resiliency such that they resist a force in a direction opposed to the orientation of the filaments. The effective length of the filaments will depend on the length to diameter ratio of the filaments. Filaments that are too short and wide and too rigid may puncture the vessel, whereas filaments too long and narrow may fold over upon themselves when a force is applied and will be unable to restrict relative movement of the vessel. The preferred length of the filaments is 0.030 to 0.075 inches, most preferably 0.060 inches. The preferred diameter of the filaments is 0.005 to 0.012 inches, preferably 0.007 inches. Wider filaments may be used, provided they are sufficiently flexible. The ends or tips of the filaments themselves can comprise a variety of shapes, as depicted in FIGS. 24 and 25. For example, filament 101 has a rounded tip, filament 102 has an angled-cut tip, filament 103 has a blunt-cut tip, filament 104 has a pointed tip, and filament 105 has a semi-rounded tip. Also, the filaments can be cylindrical 101-103, semi-cylindrical 105, or contain three sides 104 or more. The preferred filament is cylindrical with a rounded tip, as exemplified by filament 101. The pad 32 is itself comprised of a resilient material, preferably silicone. The most preferred composition of the pad 32 is two part silicone of less than a 20 durometer, liquid injection moldable (GE 6040) or a silicone foam such as GE RTF762.

[0080] Member 30 provides a rigid backing for pad 32 and means for attachment of pad 32 to opposed jaws 22 and 24. The member 30 can be made of a hard plastic, such as polycarbonate, or of metal. As depicted in FIGS. 5 and 6, a means for attaching pad 32 to an opposed jaw 22 or 24 can comprise a pair of protrusions 52 on member 30 detachably coupled to recesses 50 on the jaw.

[0081] The operation of one embodiment of the invention is depicted in FIGS. 6, 7 and 8. FIG. 6 illustrates upper and lower jaws 22 and 24, opposed members 30, 30, and opposed pads 32, 32 with resilient filaments 40 in a position to engage and occlude vessel V. FIG. 7 illustrates the above components in partial engagement with vessel V. As depicted in FIG. 7, the resilient members 32, 32 have deflected to accommodate the shape of vessel V, thereby minimizing trauma to vessel V. FIG. 8 shows the above components in complete engagement with vessel V causing occlusion of vessel V. Some of the resilient filaments have been pressed flat along the resilient members 32, 32 due to the angle at which the vessel V engages those filaments. Other resilient filaments remain generally oriented along an acute angle relative to the pads 32, 32 and abut vessel V. The abutment of some of the resilient filaments against the vessel V creates a resistive force against movement of the vessel V in a direction opposed to the orientation of the abutting filament or filaments. This resistive force assists in securing vessel V against movement relative to pads 32, 32 and opposed jaws 22 and 24.

[0082] In the embodiment illustrated in FIGS. 8 and 9A, the resilient filaments 40 are oriented such that the filaments on the lower pad 32 that abut vessel V will impart a resistive force upward, thereby pushing or levering the vessel V upward into the upper pad 32 in a direction along the general direction of orientation of resilient filaments. The resilient filaments on the upper pad 32 that abut the vessel V will impart a downward resistive force along the general direction of orientation of those particular resilient filaments. In combination, the embodiment as shown in FIG. 8 will resist movement of the occluded vessel V in one lateral direction relative to the opposed jaws 22 and 24 while permitting lateral movement of the occluded vessel V in the opposite lateral direction relative to the opposed jaws 22 and 24. In the preferred embodiment, lateral movement of the occluded vessel V will be restricted toward the distal ends of the opposed jaws 22 and 24.

[0083] In another embodiment, as depicted in FIG. 9B, the orientation of the resilient filaments of the upper opposed pad 32 can be reversed from that of FIG. 8 such that the resistive force resulting from the filaments on one jaw abutting the vessel restricts lateral movement of the vessel V in one lateral direction relative to opposed pads 32, 32, while the resistive force resulting from the filaments on the other jaw abutting the vessel restricts lateral movement of the vessel V in the opposite lateral direction relative to opposed pads 32, 32.

[0084] The resilient filaments can be arranged in one or more rows, and oriented in one or more directions. FIGS. 10-12 depict an embodiment of a particular arrangement of resilient filaments 43-45 extending from the pad 32 arranged in three distinct rows and oriented in three separate directions. The surface of pad 32 defines a plane (surface plane) containing two axes, an axis X running the length of the pad (longitudinal axis), and an axis Y oriented perpendicular to axis X (perpendicular axis). A third axis Z intersects the plane in an orientation normal to the plane (normal axis). In this embodiment, one row of resilient filaments, comprised of resilient filaments 44, is arranged in a row along longitudinal axis X, and the filaments of this row are oriented at an acute angle C from the surface of the pad 32 in a plane defined by longitudinal axis X and normal axis Z, and at an angle D from the surface in a plane defined by perpendicular axis Y and normal axis Z. A second row of resilient filaments, comprised of filaments 43, is arranged along an axis parallel to longitudinal axis X, and the filaments of this row are oriented at an angle A1 from longitudinal axis X in the surface plane, at an angle B from the surface of the pad 32 in a plane defined by longitudinal axis X and normal axis Z, and at an acute angle E1 from the surface in a plane defined by perpendicular axis Y and normal axis Z. A third set of resilient filaments, comprised of filaments 45, is likewise arranged along an axis parallel to longitudinal axis X, and the filaments of this row are oriented at an angle A2 from longitudinal axis X in the surface plane, and in a direction generally opposed to the direction of the filaments of the second row with respect to this plane, at an angle B from the surface of the pad 32 in a plane defined by longitudinal axis X and normal axis Z, and at an acute angle E2 from the surface in a plane defined by perpendicular axis Y and normal axis Z. This arrangement of resilient filaments, when engaged with a vessel, will resist movement of the vessel relative to the pad 32 in either direction along perpendicular axis Y, and will also resist movement of the vessel relative to the pad 32 in one of two directions along longitudinal axis X.

[0085] In the preferred embodiment, the angles A1, A2, B and D are approximately 90 degrees while the angles C, E1 and E2 are between 30 to 60 degrees, most preferably approximately 45 degrees. The number of resilient filaments per row can be between 8 and 32, and is preferably 16. Also, it is preferable, though not necessary, that the filaments terminate at the same height L relative to the surface of the pad 32.

[0086] An alternative arrangement of filaments is depicted in FIGS. 13-15. In this embodiment, resilient filaments extending from pad 32 (having a surface plane and longitudinal, perpendicular, and normal axes, X, Y and Z, as described above for FIGS. 10-12) are arranged in two distinct rows and are oriented in two separate directions. A first row of resilient filaments, comprised of resilient filaments 46, is arranged along an axis parallel to longitudinal axis X, and the filaments of this row are oriented at an acute angle F1 from longitudinal axis X in the surface plane, at an acute angle G from the surface of pad 32 in a plane defined by longitudinal axis X and normal axis Z, and at an acute angle H1 from the surface in a plane defined by perpendicular axis Y and normal axis Z. A second row of resilient filaments, comprised of resilient filaments 47, is likewise arranged along an axis parallel to longitudinal axis X, and the filaments of this row are oriented at an acute angle F2 from longitudinal axis X in the surface plane, at an acute angle G from the surface of the pad 32 in a plane defined by longitudinal axis X and normal axis Z, and at an acute angle H2 from the surface in a plane defined by perpendicular axis Y and normal axis Z. The sum of acute angles F1 and F2 is less than 180 degrees. This arrangement of resilient filaments, when engaged with a vessel, will resist movement of the vessel relative to the pad 32 in either direction along perpendicular axis Y, and will also resist movement of the vessel relative to the pad 32 in one of two directions along longitudinal axis X.

[0087] In the preferred embodiment, the angles F1, F2, G, H1 and H2 are between 30 to 60 degrees, most preferably approximately 45 degrees. The number of resilient filaments per row can be between 12 and 48, and is preferably 24. Also, it is preferable, though not necessary, that the filaments terminate at the same height M relative to the pad 32.

[0088] Another embodiment of the pad 32 and attaching member 30 is depicted in FIG. 16. In this embodiment, resilient filaments 40 extend outward from a position where pad 32 attaches to member 30, at an acute angle relative to the surface of pad 32. Any acute angle relative to the surface will operate to resist relative movement of an occluded vessel, the preferred angle being 45 degrees.

[0089] FIGS. 16-18A depict an embodiment of a particular arrangement of resilient filaments extending from between pad 32 and member 30 in two sets, one on each side of pad 32. Each set of filaments is organized into two intersecting groups. The filaments of both groups extend from between pad 32 and member 30 along a single plane. The filaments of each group are oriented parallel to one another and at an angle relative to the filaments of the other group. The preferred angle is a right angle. The planes defined by each set of filaments are oriented at an angle L relative to the surface of pad 32. The preferred angle L is between 45 to 90 degrees, and is most preferably 45 degrees. This arrangement of filaments, when engaged with a vessel, will resist movement of the vessel in either direction relative to the length of the pad. When angle L is less than 90 degrees, the arrangement will also resist movement of an engaged vessel in a direction transverse to the length of the pad.

[0090] As depicted in FIG. 18A, the distal ends of the filaments terminate at a position above the surface of pad 32. In an alternative embodiment depicted in FIG. 18C, the filaments terminate at a position below the surface of pad 32. In the preferred embodiment, the filaments terminate at a position slightly above the surface of pad 32. It is also preferable, although not necessary that the filaments terminate at the same height relative to the surface of pad 32.

[0091] In the embodiment depicted in FIG. 18A, the filaments 40 are mounted between pad 32 and member 30 and extend outwardly on each side of pad 32. In the preferred embodiment there shown, member 30 has a channel with angled sides that accommodate the filaments 40. The pad 32 has a bottom surface with a reciprocal shape to fit the channel of member 30. In alternative embodiments depicted in FIGS. 18B and 18C, member 30 has a channel with perpendicular sides. In these embodiments, pad 32 has a flat bottom surface and the filaments 40 are again accommodated between the bottom surface of pad 32 and the channel of member 30. In another alternative embodiment, as depicted in FIG. 18D, the pad is divided into upper and lower portions 32aand 32b,and filaments 40 are mounted between the portions and extend outwardly on each side of the pad. The lower portion 32bpreferably has a channel with angled sides for receiving the filaments 40 and the upper portion 32a,which has a reciprocally-shaped bottom surface, as depicted in FIG. 18D.

[0092] The operation of the embodiment of the invention depicted in FIGS. 16-18 is illustrated in FIG. 19. FIG. 19 illustrates upper and lower jaws 22 and 24, and opposed members 30, 30 and opposed pads 32, 32 having resilient members mounted therebetween, in partial engagement with vessel V. The filaments have engaged the vessel V, as have the resilient surfaces of pads 32, 32 which have deflected to accommodate the vessel in atraumatic fashion. The abutment of some of the filaments against the vessel V creates a resistive force against movement of the vessel. In the alternative embodiment where the distal tips terminate below the surface of the pads, the pads engage vessel V first and deflect until the filaments also engage the vessel V.

[0093] An alternative arrangement of filaments is depicted in FIGS. 20-22. In this embodiment, the filaments 40 are arranged in similar fashion to the embodiment depicted in FIG. 16. Two sets of filaments 40 extend from each side of the pad 32 and each set of filaments is organized into two groups oriented in a single plane with the filaments in each group oriented parallel to one another and at an angle to relative to the filaments of the other group, the preferred angle being a right angle. The filaments themselves, however, are mounted, and extend from, the base member 30 itself, as depicted in FIGS. 20-22. In the preferred embodiment, the distal tips of the filaments terminate at a position above the surface of pad 32. In alternative embodiments, the tips terminate at a position even with or below the surface of the pad (see, e.g., FIG. 18C). The operation of this embodiment of the invention is depicted in FIG. 23 and is essentially identical in operation to that of the embodiment described above and depicted in FIGS. 16-19.

[0094] An alternative embodiment to the above embodiments containing two or three rows of resilient filaments is depicted in FIGS. 27 and 28. In this embodiment, three distinct regions, or strips, of multiple rows of fibers 46 extend from pad 32 (having longitudinal and perpendicular axes, X and Y, as described above for FIG. 10-15). Each region or strip contains fibers that are oriented in the same general direction. The three distinct regions are oriented in similar fashion to the three rows of resilient filaments depicted in FIGS. 10-12. The fibers can be comprised of, for example, a synthetic fur. The fibers are resilient enough to resist movement of a vessel that abuts against the tips of the fibers. This arrangement of fibers, when engaged with a vessel, will likewise resist movement of the vessel relative to pad 32 in either direction along perpendicular axis Y of pad 32, and will also resist movement of the vessel in one of two directions along longitudinal axis X. The preferred method of making this embodiment of the invention is to glue or otherwise adhere resilient filaments to a suitable backing material, which is then secured to pad 32.

[0095] The manufacture of resilient filaments and pads according to the invention can be accomplished in many ways, as will be apparent to one skilled in the art. One method of manufacture is illustrated in FIGS. 24-26. As shown therein, filaments are secured in particular orientations along spines 60, 62 and 64. These spines are arranged in interlocking fashion, as shown in FIG. 25, and then embedded into pad 32, as depicted in FIG. 26. In the preferred method, the arranged spines 60, 62 and 64 are secured in a mold, which is then filled with liquid injection moldable silicone or silicone foam, and the silicone is allowed to cure to form a pad 32 around the filaments.

[0096] The embodiments of the invention described above and depicted in FIGS. 16-23 can be manufactured using a plastic weave, such as a nylon mesh or a polyester or polypropylene braid. The plastic weave is comprised of filaments useful in the present invention. The filaments of the weave extend at angles relative to one another. A cylindrical sleeve of the weave is cut in half and one portion is heat treated in a mold to shape the weave into a form that will fit into the channel portion of member 30 as described above and depicted in FIGS. 18A-18C. The treated portion of the weave is then secured in the channel portion of member 30, preferably using an adhesive, together with pad 32. As described above, the pad itself is comprised of resilient material, preferably liquid injection moldable silicone or silicone foam. In an alternative manufacturing method, the pad 32 is placed within a cylindrical or tubular sleeve of the weave and both are bonded to member 30. The weave is then cut along its axis at or near the surface of pad 32.

[0097] In the preferred method, the pad 112 is placed within the sleeve 120, as depicted in FIGS. 34A-34B. The two ends of the sleeve are then pulled in opposite directions, thereby tightening the sleeve against the pad, as shown in FIGS. 35A-35B. The sleeve 120, pad 112, and base member 110 are then bonded or otherwise secured together, as depicted in FIGS. 36A-36B. An adhesive such as cyanoacrylate, for example, LOCTITE 406, can be used to bond sleeve 120, pad 112, and base member 110 together. Excess portions of sleeve 120 extending beyond the ends of the pad 112 are then removed, resulting in pad 112 having a portion of sleeve 120 covering its surface, as depicted in FIG. 37. The weave can then be cut longitudinally, for example, along axis line O as depicted in FIG. 38A. Once cut, the resilient filaments 122 of the weave release and extend upward at acute angles relative to the surface of pad 112, as shown in FIG. 38B. In a variation of this method, the pad 112 can be placed within the sleeve 120, one side of the sleeve can be secured to the pad, and the sleeve can be cut longitudinally along the side generally opposite the secured side prior to securing the sleeve-pad assembly to the base member 110. In either case., the result is a pad according to the invention. In this manufacturing method, the most preferred material for the pad 112 is a 40 durometer urethane or extruded vinyl foam and the most preferred material for the sleeve 120 is a polypropylene braid. In the embodiment depicted in FIG. 38D, the filaments 122 extend outward at an angle P from vertical relative to the surface of the pad 112 and terminate at a height above the surface of the pad. The filaments can also extend upward in a generally vertical direction relative to the surface of the pad 112, as shown in the embodiment depicted in FIG. 38C.

[0098] FIG. 29 is a Weitlaner surgical retractor comprising a pair of opposed retracting arms 82 and 84 hinged together by pin 80. The distal ends of the retracting arms 86 and 88 terminate in retracting fingers 90, 90. The proximal ends of the arms terminate in finger and thumb rings 72 and 74 that provide for manual operation of the retracting arms by a surgeon. The proximal ends of the arms also carry an arcuate rack 78 and locking pawl 76 having interlocking ratchet teeth which engage to secure retracting arms 86 and 88 in an open position when retracting tissue at a surgical incision site.

[0099] The gripping elements of the retractor comprise base members 92 having resilient filaments that extend from the surface of the base members 92 at acute angles. Each base member 92 is securable to retracting fingers 90. As shown in FIG. 30, base member 92 contains apertures 94 which are adapted to receive retracting fingers 90 formed on the arms 86, 88. As shown in FIG. 31, each base member 92 itself has a distal edge 96 and a proximal edge 98.

[0100] As is the case with the surgical clamp discussed above, resilient filaments of base member 92 are comprised of a durable yet flexible material, such as nylon or polyester. The filaments cannot be so rigid that they puncture or otherwise traumatize the retracted tissue, but they must be of a strength and resiliency such that they resist a force in a direction opposed to the orientation of the filaments. The effective length of the filaments will depend on the length to diameter ratio of the filaments. Filaments that are too short and wide may puncture or traumatize the retracted tissue, whereas filaments too long and narrow may fold over upon themselves when a force is applied and will be unable to restrict relative movement of the retracted tissue. The preferred length of the filaments is 0.030 to 0.075 inches, most preferably 0.060 inches. The preferred diameter of the filaments is 0.005 to 0.012 inches, preferably 0.007 inches. Wider filaments can be used, provided they are sufficiently flexible. The ends or tips of the filaments themselves can comprise a variety of shapes, as depicted in FIGS. 32 and 33. For example, filament 101 has a rounded tip, filament 102 has an angled-cut tip, filament 103 has a blunt-cut tip, filament 104 has a pointed tip, and filament 105 has a semi-rounded tip. Also, the filaments can be cylindrical 101-103, semi-cylindrical 105, or contain three sides 104 or more. The preferred filament is cylindrical with a rounded tip, as exemplified by filament 101.

[0101] The surface of base member 92 can be of a resilient material, preferably silicone. The most preferred composition of the surface of base member 92 is two part silicone of less than a 20 durometer, liquid injection moldable (GE 6040) or a silicone foam such as GE RTF762.

[0102] In the embodiment shown in FIGS. 29-31, some of the resilient filaments, comprised of resilient filaments 48, are oriented to resist movement of retracted tissue T relative to the base member 92 in the direction of distal edge 96. The surface of base member 92 defines a plane containing two axes, an axis X running the length of the base member 92 (longitudinal axis) and an axis Y oriented perpendicular to the axis X (perpendicular axis). A third axis Z intersects the plane in an orientation normal to the plane (normal axis). Resilient filaments 48 are oriented at an acute angle K from the surface of base member 92 in a plane formed by perpendicular axis Y and normal axis Z. Additional resilient filaments, comprised of resilient filaments 49, are oriented at acute angles J1 and J2 from the surface of base member 92 in a plane formed by longitudinal axis X and normal axis Z. This arrangement of resilient filaments, when engaged with retracted tissue, will resist movement of the tissue relative to the surface of base member 92 in either direction along longitudinal axis X, and will also resist movement of the tissue relative to the base member 92 along perpendicular axis Y in the direction towards distal edge 96.

[0103] In the preferred embodiment, the angles J1, J2, and K are between 30-60 degrees, most preferably approximately 45 degrees, and the number of rows of resilient filaments is 10. It is preferable, though not necessary, that the filaments terminate at the same height N relative to the surface 92.

[0104] In an alternative embodiment of the invention, FIGS. 39-40 show a Richardson surgical retractor 160 comprising a handle 162, arm 164 and retracting blade 168 for retracting tissue at an incision site. The retracting blade 168 has a resilient pad 170 on the retracting surface and resilient filaments 172 according to the invention that extend from the pad surface at acute angles. Another embodiment of the invention is depicted in FIGS. 41-42, which shows a Balfour surgical retractor 180. This retractor has particular use in retracting tissue at an abdominal incision. The retractor 180 has lateral blades 181 and 182 fixed to arms 183 and 184 respectively. Arms 183 and 184 are in turn mounted on parallel bars 185 and 186, with arm 183 being movable toward and away from arm 184. Center blade 194 is fixed to arm 196, which is moveably mounted on bars 185 and 186 for movement of center blade 194 in directions perpendicular to the bars 185 and 186. Center blade 194 has a resilient pad 190 on the retracting surface and resilient filaments 192 according to the invention that extend from the pad surface at acute angles.

[0105] A surgical stabilizer according to the invention is shown in FIGS. 43-45. The stabilizer 200 includes bar 202 that is pivotally coupled to member 204. Member 204 is attached to the base of U-shaped foot member 206. Arms 207 and 208 extend from the base of foot member 206 for engagement with and stabilization of body tissue or organs. Each arm 207 and 208 includes a resilient pad 210 having resilient filaments 212 extending therefrom at acute angles relative to the pad surface. In an alternative embodiment, stabilizing members having resilient filaments can be provided that are detachably secured to the arms, according to ways described above with respect to surgical clamp pads or retractor base members. In operation, foot member 206 is pressed against the target tissue or organ to stabilize or immobilize the tissue or organ. The resilient filaments of arms 207 and 208 engage the tissue or organ and the abutment of the engaged filaments against the tissue or organ provides a resistive force that opposes movement of the tissue or organ relative to the arms. This action increases the amount of traction applied by the stabilizer to the stabilized tissue or organ.

[0106] FIG. 45 depicts stabilizer 200 in operation to immobilize a patient's beating heart in order to perform bypass surgery. Access to the heart is provided by operation of rib spreader 220 that includes base member 226, fixed member 222 and moveable member 223 which is moveable toward and away from fixed member 222 along base member 226. Rib spreading arms 224 and 225 are secured to members 222 and 223, respectively. The arms 224 and 225 are inserted into an incision and between two adjacent ribs over the heart. Using conventional means not shown, arm 225 and member 223 are moved away from arm 224 and member 222, thereby spreading apart the ribs and providing access to the heart and surrounding tissues. Arms 224 and 225 are secured in a fixed spaced apart relationship by the tightening of tumscrew 228 down onto a channel formed in base member 226. Stabilizer 200 is then positioned to impart pressure against the heart to hold it in an immobilized position while it continues beating. The stabilizer 200 is fixed in pressure-bearing position by means of fastener 214 that secures stabilizer bar 202 against base member 226. The secured stabilizer keeps that portion of the heart between arms 207 and 208 adequately immobilized to allow graft procedures, including anastomosis, to be effectively performed. At the same time, the improved traction provided by the resilient filaments that engage the heart further prevent shifting or movement of the heart, yet do so in atraumatic fashion.

[0107] Although only certain embodiments have been illustrated and described, those having ordinary skill in the art will understand that the invention is not intended to be limited to the specifics of these embodiments, but rather is defined by the accompanying claims.