Surgical instruments for stabilizing the beating heart during coronary artery bypass graft surgery

We claim:

1. A device for performing a surgical procedure on a beating heart, comprising:

a stable platform;

mounting means secured to the platform;

shaft means having at a distal end a contact member for engaging the surface of the beating heart, said shaft means including a ball and socket means coupling the contact member to the distal end of the shaft means;

a pushrod translatably disposed in the shaft means with a distal end bearing against the ball;

shaft support means having a moveable portion adapted to lock onto the mounting means while simultaneously locking thereto the shaft means, with the contact member in selective engagement with the beating heart; and

handle means secured at an angle to a proximal end of the shaft means for imparting translation to the pushrod to lock the contact member in the selective engagement with the beating heart.

2. The device of claim 1 wherein the mounting means includes:

first pedestal means affixed to the platform; and

base means having the moveable portion adapted to lock onto the first pedestal means.

3. The device of claim 2 wherein the base means includes:

a generally hollow base wherein the moveable portion includes first clamping means engaging the first pedestal means;

means for locking the first clamping means to said first pedestal means; and

circular pedestal means formed in the base means.

4. The device of claim 3 wherein the shaft support means includes:

a pair of confronting housings adapted to have initial contact at upper points of contact;

one of the housings having second clamping means contacting the circular pedestal means of the base means while allowing rotation of the shaft support means relative to the base means; and

means supported within the housings for forcing the housings to pivot about the upper points of contact to lock the second clamping means to the circular pedestal means while simultaneously locking thereto the shaft means.

5. The device of claim 4 wherein the shaft support means further includes:

a stationary wall having a stationary complementing part of the second clamping means which matches the circular pedestal means; and

said means for forcing the housings include screw means rotatably secured within said housings for forcing a moveable portion of the second clamping means towards the stationary part of the second clamping means to lock the shaft support means to the circular pedestal means.

6. The device of claim 4 wherein:

said first clamping means and said first pedestal means comprise matching female dovetail means and a male dovetail member, respectively; and

said second clamping means and said circular pedestal means comprise matching female arcuate dovetail means and a male circular dovetail member, respectively.

7. The device of claim 2 wherein:

said first pedestal means comprises first dovetail means;

said base means comprises; second dovetail means in the moveable portion thereof which matches the first dovetail means, and lever means for applying a force to the moveable portion to lock the second dovetail means to the first dovetail means; and

said shaft support means comprises; confronting complementary housings having an arcuate dovetail means formed in the moveable portion thereof, screw means including a knob rotatably supported in one housing, shaft grip means rotatably supported in the other housing and having one end enclosing the shaft means and the other end threaded to engage the screw means, and friction means disposed between the shaft means and said other housing for applying light friction against the shaft means when the screw means is not tightened and for locking the shaft means and the shaft support means to the base means when the screw means is tightened.

8. The device of claim 7 wherein:

rotation of the screw means draws the grip means against the shaft means, forcing engagement of the friction means with said other housing, which forces the moveable arcuate dovetail means to lock to the base means to thereby lock the shaft means and the shaft support means from further movement.

9. The device of claim 1 wherein the shaft support means includes:

confronting housings having respective common areas at which initial contact is made when the housings are first forced together;

one of the housings including a moveable arcuate clamping means for providing said lock to the mounting means;

means for maneuverably gripping the shaft means; and

means supported within the housings for forcing the housings together about said common areas to lock the shaft means to the gripping means while simultaneously locking the moveable arcuate clamping means to the mounting means.

10. The device of claim 9 wherein the means for forcing includes:

screw means supported within the housings and threadably engaging the gripping means; and

wherein rotation of the screw means imparts translation of the gripping means relative to the shaft means to force the housings together about the mounting means.

11. The device of claim 10 wherein:

said mounting means includes circular pedestal means matching the moveable arcuate clamping means; and

said gripping means includes an annular groove and said housings include associated hooked clips which snap into the annular groove to loosely assemble the shaft support means together while allowing orientation of the shaft means and of the contact member relative to the beating heart, prior to the locking process.

12. The device of claim 10 wherein:

the shaft support means is rotatable relative to the mounting means about a generally vertical first axis;

the engaged screw means and gripping means are rotatable within the housings to allow corresponding rotation of the shaft means about a generally horizontal second axis; and

the shaft means is rotatable within the gripping means about a third axis generally perpendicular to the second axis and is translatable relative to the gripping means.

13. The device of claim 9 wherein the shaft support means further includes:

friction means disposed between a first of the housings and the shaft means for preventing movement of the shaft means when the means for forcing is locked.

14. The device of claim 13 wherein the friction means comprises:

shaft locking means disposed against the shaft means; and

a friction assembly disposed between the shaft locking means and the first housing.

15. The device of claim 14 wherein the friction assembly includes:

a housing friction disk keyed to the first housing; and

a grip friction disk disposed against the housing friction disk and keyed to the gripping means.

16. The device of claim 15 including:

spring means disposed to consistently apply friction against the shaft means.

17. The device of claim 14 wherein the friction assembly includes:

annular teeth formed in a surface of the shaft locking means facing the first housing; and

complementary annular teeth formed in a confronting surface of the first housing, wherein securing the means for forcing forces the confronting teeth to firmly mesh in wedge-surface frictional engagement.

18. The device of claim 1 wherein the shaft means further includes a mechanism for providing a preloaded force against said ball and socket means, said force sufficient to maintain said contact member in a selected orientation.

19. The device of claim 18 wherein said mechanism comprises a compression spring.

20. The device of claim 1 wherein the handle means includes:

screw means rotatably secured in the proximal end of the handle; and

a wedge moveably supported in the curved handle and abutting a proximal end of the pushrod;

wherein rotation of the screw means imparts movement to the wedge and to the pushrod to lock the ball and socket means and thereby lock the contact member in said selective engagement.

21. The device of claim 1 wherein the contact member is shaped in the configuration of a re-curve such that the surface thereof that engages the heart is the surface facing the distal end of the shaft means.

22. The device of claim 21 wherein the contact member includes:

a common base portion suitably affixed to the distal end of the shaft means; and

a pair of spaced members extending from the common base portion in the re-curve configuration to engage the surface of the beating heart.

23. The device of claim 1 wherein the shaft support means supports the shaft means on the mounting means while allowing several degrees of freedom of movement of the shaft means relative to the shaft support means and mounting means, prior to the locking procedures.

24. The device of claim 23 wherein:

the shaft support means is adapted for rotation relative to the mounting means about a generally vertical first axis;

the shaft means is adapted for rotation relative to the shaft support means about a generally horizontal second axis; and

the shaft means further is adapted for rotation about a third axis generally perpendicular to the second axis while being translatable along the third axis.

25. A device for performing a surgical procedure on a beating heart, comprising:

a stable platform

circular pedestal means selectively secured to the platform;

shaft means including handle means at a proximal end thereof and a contact member at a distal end thereof, said handle means being adapted to lock the contact member in a selected orientation relative to the beating heart; and

shaft support means supporting the shaft means in a selected orientation and having arcuate clamping means contacting the circular pedestal means, said arcuate clamping means being moveable to detachably lock the shaft support means to the circular pedestal means while the shaft means simultaneously is being locked to the shaft support means.

26. A device for performing a surgical procedure on a beating heart, comprising:

a stable platform;

mounting means selectively secured to the platform;

first adjusting means detachably secured to the mounting means;

second adjusting means having at a distal end thereof a contact member for engagement with the beating heart;

said second adjusting means being supported by the first adjusting means for translation and rotation about several degrees of freedom of movement relative to the first adjusting means and the mounting means, to enable selective engagement of the contact member with the beating heart;

second mounting means selectively secured to the platform;

auxiliary base means detachably secured to the second mounting means; and

deformable support means secured at a proximal end thereof to the auxiliary base means for maneuverable supporting at a distal end thereof an auxiliary surgical instrument.

27. The device of claim 26 wherein:

said first adjusting means is adapted for rotation relative to the mounting means about a generally vertical axis;

said second adjusting means is adapted for rotation about a generally horizontal axis, as well as for translation and rotation relative to the first adjusting means about an axis perpendicular to the generally horizontal axis; and

said contact member is tiltably secured to the distal end of the second adjusting means.

28. A device for performing a surgical procedure on a beating heart, comprising:

a stable platform;

heart contacting means shaped to engage the surface of the beating heart to stabilize the heart;

shaft means for maneuverably supporting and locking the heart contacting means in selective engagement with the beating heart surface, said shaft means having distal and proximal ends and including ball/socket means tiltably securing the heart contacting means to the distal end of the shaft means and a first mechanism integral with the proximal end of the shaft means for locking the heart contacting means in the selective engagement; and

second adjusting means for maneuverably supporting and locking the first adjusting means thereto, and including means for detachably securing the first adjusting means to the platform.

29. The device of claim 28 wherein the means for detachably securing the second adjusting means includes:

mounting means selectively secured to the platform and including circular pedestal means for rotatably securing the first adjusting means thereto.

30. The device of claim 29 wherein the second adjusting means comprises shaft support means including:

means for gripping the first adjusting means;

arcuate clamping means for detachably securing the shaft support means to the circular pedestal means of the mounting means; and

a second mechanism for urging the arcuate clamping means into securing the shaft support means to the mounting means while simultaneously locking the first adjusting means via the gripping means.

31. The device of claim 29 wherein the mounting means comprises:

pedestal means selectively secured to the platform; and

base means including, base clamping means for detachably securing the base means to the pedestal means, and a third mechanism for urging the base clamping means into locking the base means to the pedestal means.

32. A stabilizing device for enabling a surgical procedure on a beating heart, comprising:

a shaft member having a proximal end and a distal end;

a stabilizing member operably attached to said distal end, said stabilizing member having a common base portion and first and second contact members extending in a parallel orientation from said base portion, said first and second contact members each having a contact surface adapted to frictionally engage the surface of the beating heart; and

said base portion, said first contact member, and said second contact member being formed from a unitary piece of stainless steel sheet material.

33. The stabilizing device of claim 32 wherein said stainless steel sheet material has a predetermined thickness, said thickness being substantially less than the width of said contact members.

34. The stabilizing device of claim 32 wherein each of said contact surfaces are substantially rectangular.

35. The stabilizing device of claim 34 wherein each of said contact surfaces are substantially planar.

36. The stabilizing device of claim 32 wherein each of said contact members have a re-curve portion extending at an acute angle relative to said contact surfaces.

37. The stabilizing device of claim 32 wherein said shaft member is curved.

38. A stabilizing device for enabling a surgical procedure on a beating heart, comprising:

a shaft member having a proximal end and a distal end, said distal end having a ball socket fixed thereto, said ball socket having a plurality of slots;

a stabilizing member having at least one contact member adapted to engage the surface of the beating heart; said stabilizing member having a post extending therefrom, said post having a ball-shaped member attached to a proximal end thereof and said ball-shaped member being sized to fit within said ball socket; said ball-shaped member being operably engaged within said ball socket such that said stabilizing member is tiltable relative to said shaft to achieve a plurality of desired orientations, at least one of said orientations placing said post within one of said plurality of slots.

39. The stabilizing device of claim 38 wherein said ball socket has four slots.

40. The stabilizing device of claim 38 wherein said stabilizing member has a common base portion and first and second contact members extending in a parallel orientation from said base portion, said first and second contact members each having a contact surface adapted to frictionally engage the surface of the beating heart, said post extending from said base portion.

41. The stabilizing device of claim 40 wherein said base portion, said first contact member, and said second contact member being formed from a unitary piece of stainless steel sheet material.

42. The stabilizing device of claim 41 wherein said sheet material has a predetermined thickness, said thickness being substantially less than the width of said contact members.

43. A device for performing a surgical procedure on a beating heart, comprising:

a stable platform having a pedestal means selectively secured thereto;

shaft means including handle means at a proximal end thereof and a contact member at a distal end thereof, said handle means being adapted to lock the contact member in a selected orientation relative to the heart; and

shaft support means supporting the shaft means in a selected orientation and having arcuate clamping means contacting the pedestal means, said arcuate clamping means being moveable to detachably lock the shaft support means to the pedestal means while the shaft means simultaneously is being locked to the shaft support means.

Description Submit all comments and votes

Diseases of the cardiovascular system affect millions of people each year and are a leading cause of death throughout the world. The costs to society from such diseases is enormous both in terms of the lives lost and in terms of the cost of treating patients through traditional surgical techniques. A particularly prevalent form of cardiovascular disease is a reduction in the blood supply leading to the heart caused by atherosclerosis or other condition that creates a restriction in blood flow at a critical point in the cardiovascular system that supplies blood to the heart. In many cases, such a blockage or restriction in the blood flow leading to the heart is treated by a surgical procedure known as a Coronary Artery Bypass Graft (CABG) procedure, more commonly known as a "heart bypass" operation. In the CABG procedure, the surgeon "bypasses" the obstruction to restore normal blood flow to the heart by attaching an available source vessel to an obstructed target coronary artery or by removing a portion of a vein or artery from another part of the body, to use as a graft, and by installing the graft at points between a source vessel and a target artery to restore normal blood flow.

Although the CABG procedure has become relatively common, the procedure itself is lengthy and traumatic and can damage the heart, the cardiovascular system, the central nervous system, and the blood supply itself. In a conventional CABG procedure, the surgeon must make a long incision down the center of the chest, cut through the entire length of the sternum, perform several other procedures necessary to attach the patient to a heart-lung bypass machine, cut off the blood flow to the heart, and then stop the heart from beating in order to complete the bypass. The most lengthy and traumatic surgical procedures are necessary, in part, to connect the patient to a cardiopulmonary bypass (CPB) machine to continue the circulation of oxygenated blood to the rest of the body while the bypass is completed.

Although several efforts have been made to make the CABG procedure less invasive and less traumatic, most techniques still require cardiopulmonary bypass (CPB) and cardioplegia (stopping the heart). The safety and efficacy of the CABG procedure could be improved if the surgeon could avoid the need to stop the heart from beating during the procedure, thereby eliminating cardiopulmonary bypass and the lengthy and traumatic surgical procedures necessary to connect the patient to a cardiopulmonary bypass machine to sustain the patient's life during the procedure. In recent years, a small number of surgeons have begun performing CABG procedures using surgical techniques especially developed so that the CABG procedure could be performed while the heart is still beating. In such procedures, there is no need for any form of cardiopulmonary bypass, no need to perform the extensive surgical procedures necessary to connect the patient to a cardiopulmonary bypass machine, and no need to stop the heart. As a result, the surgery is much less invasive and the entire procedure can typically be achieved through a small number, typically one or two, comparatively small incisions in the chest.

Despite the advantages, the beating-heart CABG procedure is not widely practiced, in part, because of the difficulty in performing the necessary surgical procedures using conventional surgical instruments. If specially designed instruments were available so that the CABG procedure could be performed on the beating heart, the beating-heart CABG procedure would be more widely practiced and the treatment of cardiovascular disease in a significant patient population would be improved.

As noted above, the CABG procedure requires that a fluid connection for restoring the flow of blood be established between two points to "bypass" a diseased or obstructed area to restore blood flow to the heart. This procedure is known as an "anastomosis." Typically, a source vessel, such as a source artery with an unobstructed blood flow, i.e., the left internal mammary artery (LIMA), or a bypass-graft having one end sewn to an unobstructed blood source such as the aorta, is sewn to a target occluded coronary artery, such as the left anterior descending (LAD) artery or other vessel, that provides blood flow to the muscles of the heart. Because the beating-heart CABG procedure is performed while the heart muscle is continuing to contract and pump blood, the anastomosis procedure is difficult to perform because the heart continues to move while the surgeon is sewing the anastomosis.

The specific part of the surgical procedure that creates the anastomosis in the beating-heart CABG procedure requires placing a series of sutures through extremely small vessels on the surface of the heart and requires completing the anastomosis while the heart muscle continues to beat to pump blood during the procedure. Moreover, the sutures must be carefully placed so that the source vessel or graft is firmly attached when the anastomosis is complete and does not leak when blood flow through the vessel is established. It is also important that the anastomosis procedure be performed rapidly because the blood flow through the target coronary artery may be temporarily interrupted or reduced to avoid excessive blood loss. Also, the working space and visual access are limited because the surgeon may be working through a small incision in the chest or may be viewing the procedure on a video monitor if the site of the surgery is viewed via a surgical scope.

In one current practice, the surgeon places sutures through the heart tissue and, by exerting opposing tension on the sutures, stretches the tissue surrounding the site of the anastomosis to partially reduce the motion of the heart while the anastomosis is completed. This approach is far from ideal. Alternatively, a suction device may be attached to the surface of the heart to fix the motion of the outer layer of surface tissue. In such cases, a suction device typically has several ports incorporated into an instrument that may be attached to the heart to apply a negative pressure to the surface tissue. The negative pressure essentially attaches the surface tissue to the apparatus thereby fixing the position of a portion of the surface of the heart. Such devices are described in co-pending U.S. patent application Ser. No. 603,328 (U.S. Pat. No. 5,894,843).

While the negative pressure approach may be effective in fixing a portion of the surface tissue of the heart, the negative pressure applied to cardiac tissue can result in temporary hematomas at the site where the suction ports attach to the tissue. Also, the exterior cardiac tissue is fixed in a configuration defined by the shape of the instrument and the orientation of the suction ports. While the heart continues to beat, the heart muscles are contracting to pump blood, which results in the muscles exerting a force directed away from the exterior tissue fixed by suction.

The beating-heart CABG procedure could be greatly improved if the heart could be stabilized during the procedure such that the motion of the heart, particularly at the site of the anastomosis, is minimized even though the heart continues to beat to supply blood to the body. If effective means for stabilizing the beating heart were available, the beating-heart CABG procedure could be performed more easily, more rapidly, more safely, and with less trauma to the patient.

SUMMARY OF INVENTION

The advantages provided to a surgeon by the instruments and techniques of the invention allow the beating heart CABG procedure to be performed more rapidly, with less trauma to the patient, and enable a surgeon to perform a CABG procedure without CPB or cardioplegia. This invention provides an alternative approach to a suction apparatus by providing devices and methods for stabilizing the motion of the heart using mechanical instruments specially designed to apply a stabilizing force to the heart to minimize the motion of the beating heart during a surgical procedure. The invention enables a surgeon to readily and rapidly perform a beating-heart CABG procedure thus avoiding the need for cardioplegia or cardiopulmonary bypass. In particular, the methods and devices described herein enable the surgeon to stabilize the heart such that an anastomosis can be more readily accomplished by enabling the surgeon to attach a source vessel or bypass graft to a target coronary artery whose motion is minimized for the duration of the surgical procedure.

Pursuant to the invention, a stabilizing device is introduced through a suitable opening in the chest that provides access to the beating heart. By contacting the heart with the means for stabilizing the beating heart of this invention, and by exerting a stabilizing force on the heart, the motion of the heart caused by the contraction of the heart muscles is effectively eliminated such that movement of the target artery at the site of the anastomosis is minimized. The remainder of the heart may be allowed to contract normally or may have additional devices in place to support the heart or to restrain its motion. Additionally, several of the devices of the invention may be used to position the beating heart to provide an improved surgical field, to maintain the heart in a preferred configuration for surgery, or to rotate the heart to present distinct features of the heart to the surgeon's visible and accessible surgical field.

An important advantage of this invention is derived from the discovery that a new and effective technique can be described herein and performed in surgery using the devices of the invention to provide an advantageous technique for stabilizing or positioning the beating heart during a surgical procedure. The procedure for stabilizing the beating heart generally requires exerting a stabilizing force on the beating heart using devices constructed as described herein. Typically, in separate steps, the surgeon contacts the heart with at least one component of the means for stabilizing the beating heart of this invention, assesses the degree of movement of the heart, particularly at the site of the surgery, and positions the component of the stabilizing means proximate to the site of the surgery such as a target coronary artery of an anastomosis. With the functional portion of a stabilizing means in place, the surgeon applies a stabilizing force to the beating heart such that the portion of the instrument in contact with the surface of the heart displaces the surface of the heart a sufficient distance that the contraction of the heart does not cause substantial motion, either vertical or horizontal, at the surgery site. The stabilizing force is applied directly or indirectly using at least one component of the stabilizing means of the invention and is comprised of exerting a mechanical force onto the beating heart, generally at a specific location such as a target coronary artery and generally exerting force that is at least partially applied in a direction perpendicular to the surface of the beating heart. Thus, an important aspect of this invention is the discovery that the beating heart may be effectively stabilized for the purpose of a surgical procedure by using a specially designed instrument as described herein to exert a mechanical stabilizing force on the exterior of the heart, particularly where the force is exerted proximate to the site of the surgery. The stabilizing force may consist of a force that resists the motion supplied by the beating heart, or additional forces applied to the heart, or the stabilizing force.

By fixing the position of the stabilizing means in a configuration where the motion of the beating heart is effectively eliminated, the surgeon maintains the stabilizing force on the beating heart for the duration of the procedure. To fix the position of the means for stabilizing the beating heart, the stabilizing means may be attached to a retractor used to separate the ribs or to another fixed support. The stabilizing means may also be attached to a comformable, flexible, or semi-rigid arm or shaft means which is rendered substantially rigid mechanically, chemically, or by human intervention. In certain preferred embodiments, the stabilizing means has an adjustable shaft means which may be oriented in several directions and has a fixture adapted to be attached to a retractor. In a preferred technique of the invention, the surgeon first performs a thoracotomy and retracts the ribs using a retractor, which may then be locked in an open position providing access to the beating heart. The surgeon then contacts the surface of the heart with a component of the stabilizing means, which has been provided with an adjustable shaft, at a point proximate to the target coronary artery, and exerts a stabilizing force on the means for stabilizing the beating heart. By manipulating the adjustable shaft, the site of the surgery will become substantially motionless. This force may be advantageously applied, and the absolute amount of force minimized with the additional feature of an adhesive or high-friction surface on the component of the stabilizing means that contacts the beating heart. At this point, the adjustable shaft means is fixed in position, for example by being stably attached to the retractor, thereby rendering the target coronary artery substantially motionless for the duration of the procedure.

DESCRIPTION OF THE FIGURES

FIG. 1 is a means for stabilizing the beating heart having a pair of substantially planar contact members which are oriented to engage the heart proximate to the site at which a bypass will be sewn. FIG. 1 also shows the contact members attached to a shaft means which may be adjustable in several directions and which may be attached to a retractor or other fixed support structure.

FIG. 1A is a detail of the shaft means and the structure of the adjustable positioning mechanisms.

FIGS. 1B through 1G are various configurations of a contact member having a friction means which is preferably affixed to the bottom surface of the contact member.

FIG. 2 is an example of a snap-on member affixed to the bottom surface of a contact member for ease of manufacture and disposability advantages.

FIG. 3 is an example of a stabilizing means of the invention having an inflatable or fluid-filled cushioning member disposed between the bottom surface of the contact member and the surface of the beating heart.

FIGS. 4A through 4C are an embodiment of the invention having weighted contact members that engage the beating heart, and which may be part of a system to achieve stabilization of the heart by applying a stabilizing force via a balanced mass having an adjustable weight and counterweight configuration. FIG. 4A shows the weighted contact member in cross section. FIG. 4B is the contact members having an opening disposed therebetween for positioning of a vessel. FIG. 4C shows the contact member coupled to a shaft that is affixed to a fulcrum having an adjustable weight and a counter-weight.

FIG. 5 is an embodiment of the invention having a counter-contact member positioned opposite a pair of contact members and having a shaft positioned at an intermediate point therebetween.

FIGS. 6A and 6B are embodiments of the invention having contact members which have a conformable shape, and where a flexible or semi-rigid member may be passed through the body of the contact member.

FIG. 7A is an embodiment of the contact member wherein the contact member has ports for releasable attachment of the distal end of a shaft means. FIG. 7B is an embodiment wherein a plurality of ports are disposed about the periphery of a contact member for releasable attachment to the distal end of a shaft means. FIG. 7C is an embodiment of the invention wherein a separate shaft is provided having distal portions adapted to fit within ports on a contact member. FIGS. 7D and 7E are an embodiment of the invention wherein the contact members are formed from the distal portion of a shaft means for minimally invasive applications. FIG. 7E shows an interconnecting member for joining the distal portions of the shaft means.

FIG. 8 is an embodiment of the invention having a substantially annular contact member which is affixed to a shaft which is rotatable about the annular contact member and which may be locked into position at a given point about the periphery of the contact member.

FIGS. 9A through 9G are embodiments of the invention where a positive or negative pressure is provided proximate to the contact members.

FIG. 9H is an embodiment of the invention where a light source is provided to illuminate the area that the beating heart contacted by the contact members.

FIGS. 10A through 10C are embodiments of the invention where a surgical drape is operably associated with the contact members to provide an isolated visual field.

FIG. 11 is the contact members of the invention having an associated apparatus to facilitate completing the anastomosis.

FIG. 12 is an embodiment of the invention where the shaft means has associated therewith a separate vessel holder.

FIGS. 13A through 13E are a cannula assembly preferred for providing minimally invasive access for the stabilizing means of the invention. FIG. 13A has screws for attaching the cannula assembly to the chest wall. FIG. 13B has a threaded portion about the periphery of the cannula. FIGS. 13C through 13E are a locking mechanism designed to engage adjacent ribs.

FIG. 14 is a conical cannula having a smaller distal end to engage the surface of the beating heart and a larger proximal opening for introducing surgical instruments to the beating heart.

FIGS. 15A and 15B are an embodiment of the invention inserted through the chest wall in a minimally invasive fashion via a cannula to bring the contact members into engagement with the beating heart.

FIGS. 16A through 16E are an embodiment of the invention design for minimally invasive insertion and removal of flexible contact members whereby the contact members are maintained in a retracted state within a hollow portion of a shaft and are deployed upon extension of a central shaft.

FIGS. 17A through 17D are an additional embodiment providing minimally invasive insertion and removal of the contact members of the invention whereby individual contact members are rotated into position by a hinge at the distal end of a shaft.

FIGS. 18A through 18D are contact members which are attached to a guide that is positioned about a shaft such that downward movement of the guide causes the contact members to be deployed.

FIGS. 19A and 19B are contact members of the invention attached to a shaft means by a plurality of struts that extend the contact members into position.

FIGS. 20A through 20E are contact members of the invention that are rotatable about the distal portion of a shaft means by a plurality of hinges.

FIGS. 21A through 21C are an embodiment having contact members formed from a unitary wire which is looped such that when extended from a body of the device, the contact members are deployed, and may be removed in a minimally invasive fashion by withdrawing a portion of the wire into the body of the device.

FIGS. 22A through 22C are an embodiment of the invention wherein the contact members are formed from a helical coil which may be withdrawn into the hollow portion of a shaft for minimally invasive insertion and removal.

FIGS. 23A and 23B are inflatable contact members that may be deflated for insertion or removal by being drawn into the body of a shaft.

FIGS. 24A and 24B are a contact member of the invention formed from an inflatable annular cuff.

FIGS. 25A and 25B are contact members formed from the divided portion of the distal end of a shaft.

FIGS. 26A through 26C are contact members having sutures associated therewith for manipulation of a target artery.

FIGS. 27A and 27B are an intravessel stabilizer adapted to fit within the target coronary artery.

FIGS. 28A and 28B are contact members of the invention having means associated therewith for positioning said epicardial tissue.

FIGS. 29A and 29B are contact members of the invention having rotatable cylindrical rollers for collecting or spreading epicardial tissue proximate to a target artery.

FIG. 30 is a means for stabilizing the beating heart having a pair of contact members which are additionally comprised of a spring-tensioned frame having an extension that engages and spreads the tissue at the site of the surgery to better expose the coronary artery.

FIGS. 31A and 31B are embodiments of the stabilizing means having a single shaft means associated with each contact member and where the shaft means are interconnected and can be moved independently about a pivot such that the contact members spread the surface tissue of the heart proximate to the target coronary artery to increase exposure of the target artery at the site of the anastomosis.

FIGS. 32A through 32C are embodiments of the invention wherein the contact members have additional structures associated therewith for retraction of epicardial tissue, the epicardial retractors may be comprised of pins which extend from the bottom surface of the contact member.

FIGS. 33A and 33B are means for stabilizing the beating heart comprising a system which incorporates the retractor which spreads the ribs to provide surgical access to the heart. The stabilizing means is comprised of a pair of stabilizing plates which may be used together with a lever device to improve exposure of the target coronary artery.

FIGS. 34A through 34D are an embodiment of the invention having a lockable mechanism for depressing epicardial tissue on either side of a target coronary artery.

FIG. 35 is a substantially planar stabilizing platform which contacts the heart at a site proximate to and surrounding the coronary vessel. The platform may also have associated therewith at least one occluder which restricts or eliminates blood flow through an artery and an associated device for spreading the tissue proximate to the anastomosis.

FIG. 36 is an artery occluder comprised of a shaft portion and having a blunt portion to engage a target artery.

FIGS. 37A through 37C are contact members having structures associated therewith for occluding the target coronary artery.

FIGS. 38A and 38B are contact members of the invention having a flange associated therewith for use with sutures that surround the target vessel and may be used in connection with a movable shaft or suture guide to occlude the target vessel.

FIG. 39 is an embodiment of the contact member of the invention having one or more fixtures attached, preferably to a planar surface thereof, and adapted to receive a surgical tool or accessory such as scissors, forceps, or surgical needles for the convenience of the surgeon during the anastomosis procedure.

FIG. 40 is an embodiment of the invention having flex joints between the contact members, the interconnecting shaft, or the shaft means to provide continuous positioning of the contact members.

FIG. 41 is an embodiment of the invention having lockable joints associated with the shaft means.

FIG. 42 is a flexible, lockable arm which allows positioning in every direction to place and orient the contact members until the requisite degree of stabilization is achieved at which point the arm having a stabilizing means is fixed in position. The flexible, lockable arm may be attached to a retractor and is caused to become rigid when the entire stabilizing means is properly positioned.

FIG. 43 is a conformable, lockable arm having hollow cylinders and spheres and an inflatable balloon member disposed therein to lock the arm into position.

FIGS. 44A and 44B are embodiments of the invention having curved interlocking segments wherein teeth formed at the interconnecting surfaces of each segment prevent rotation of the respective segments.

FIGS. 45A and 45B are a flexible shaft having means incorporated therein for fixing the position of the shaft.

FIGS. 46A through 46C are an embodiment of the invention where a series of adjustable links have a elastomeric hydraulic median disposed therein and where application of force causes the elastomeric hydraulic median to become rigid and fixes the position of the adjustable links.

FIG. 47 is an embodiment of the invention having a flexible shaft with a plurality of strands located therein wherein locking the strands in position at a distal portion causes the shaft to become rigid.

FIG. 48 is a flexible shaft having a plurality of lumens disposed therein such that sealing of the lumens fixes the position of the flexible shaft.

FIG. 49 is a fine adjusting mechanism wherein a plurality of threaded cables are attached to a proximal portion of a shaft means whereby turning the threaded cables causes the proximal portion of the shaft means to be adjusted.

FIGS. 50A and 50B are embodiments of the shaft means having spring-loaded or air-damping mechanisms to restrict the vertical motion of the shaft relative to a stable support.

FIG. 51A and 51B are shaft means of the invention provided with fine adjustment mechanisms for vertical positioning of the shaft.

FIG. 52 is a malleable shaft that is mounted on a fixture attached to a retractor blade and having a handle for vertical positioning of the shaft.

FIG. 53 is a shaft means comprised of an adjustable arm formed from several interlocking segments attached to a cable.

FIGS. 54A through 54C are an adjustable shaft means of the invention wherein the position of the contact members are adjusted by a positioning handle located at the proximal portion of the shaft means and connected to a ball joint at the distal portion by a plurality of positioning wires.

FIG. 55A is an embodiment of the stabilizing means of the invention having stabilizer bars suspended from the bottom side of a rib retractor wherein the stabilizer bars engage a ratchet means. FIG. 55B has malleable shafts attached to a retractor and to the contact members.

FIGS. 56A through 56D are a shaft means of the invention having mechanisms for adjustable positioning of the shaft relative to a stable support.

FIG. 57 is an adjustable arm for attaching a shaft means of the invention to a stable support wherein the shaft means passes through a ball joint that is adjustable by a fixture on the arm and wherein the arm is locked in place on the stable support by a latch mechanism.

FIGS. 58A through 58C are embodiments of the shaft means of the invention for adjustable positioning of the shaft means relative to a retractor blade.

FIGS. 59A through 59C are adjustable shaft means of the invention that extend from a retractor blade or a retractor arm and are continuously positioned relative to the retractor blade or retractor arm.

FIG. 60 is an embodiment having a central shaft with a handle at the proximal end that is positioned by a plurality of shaft guides which are preferably attached to a interconnecting arm affixed to a retractor.

FIG. 61 is an embodiment of the stabilizing means of the invention having a pair of plates operably associated with a rib retractor and a sphere disposed between the plates to facilitate orientation of the shaft means.

FIG. 62 is an embodiment of the invention having a shaft means comprised of an arm which extends from the interconnecting bar of a retractor to a position below the retractor blades and has a substantially horizontal shaft.

FIG. 63 is the means for stabilizing the beating heart of the invention operably associated with a rib locking mechanism.

FIG. 64 is the stabilizing means of the invention adapted to be used as a means for positioning the beating heart, wherein the means are operably associated with a rib locking mechanism.

FIGS. 65A through 65D are embodiments of the invention where the shaft means is comprised of a unitary hollow shaft.

FIG. 66 is a means for stabilizing the beating heart having a sheath member with several pliable support attachments associated therewith which may include or be comprised of inflatable members which are positioned at one or several locations surrounding the heart and may have a lumen disposed within the sheath member for the introduction of air or a biocompatible fluid.

FIG. 67 is a stabilizing means formed from a movable sheath member that is attached at either end to cranks mounted on the arms of a retractor.

FIGS. 68A through 68C are a device for advantageous positioning of the heart comprised of a flexible sheet, preferably having a hydrogel coating on one side.

FIG. 69 is an embodiment of the invention comprised of a plurality of telescoping shafts having the contact member affixed at their distal end and wherein the position of the telescoping shaft is manipulated and fixed by a hydraulic actuators.

FIG. 70A through 70D are an embodiment of the invention having a conformable arm comprised of a plurality of friction joints that are engaged when the motion of the beating heart presses against the contact member.

FIGS. 71A through 71D are an embodiment of the invention having a contractible shaft attached to a flexible slide. The flexible slide is designed to be inserted into a seed-shaped clip which may be attached to a retractor blade. The contractible shaft is extended to engage the beating heart by application of hydraulic pressure, for example, by a syringe that is preferably supplied with a one-way releasable valve.

FIG. 72 is a view of the interior of the chest cavity during a CABG procedure on the beating heart with the stabilizing means operably associated with a retractor and being used in conjunction with other surgical apparatus to facilitate completing the anastomosis.

FIGS. 73 and 74 show the stabilizing means of the invention having been introduced through a thoracotomy to contact the beating heart to engage the heart tissue on either side of a target coronary artery to which an anastomosis is sewn.

FIG. 75 is an embodiment of the invention having a pair of shaft means operably associated with ball joints that are affixed to opposing arms of a retractor.

FIG. 76 is a further embodiment of the invention including means for stabilizing the beating heart and a quick-locking base/shaft lock mechanism for solid attachment of the stabilizing means to a stable platform.

FIG. 77 is an exploded perspective view of the stabilizing means of FIG. 76, including a shaft-locking support mechanism for maneuverably supporting a shaft means of the stabilizing means.

FIGS. 78 and 79 are perspective views of the top and bottom, respectively, of a base of FIGS. 76, 77.

FIG. 78A is a perspective view of one side of a pedestal means formed on a retractor arm.

FIG. 80 is a side view of the base of FIGS. 76-79 locked to a retractor arm.

FIG. 81 is a cross-sectional view of the base and retractor arm taken along section line 81--81 of FIG. 80.

FIGS. 82 and 83 are side and top cross-sectional views respectively, of the shaft-locking support mechanism of FIG. 77.

FIGS. 82A and 82B are a cross-sectional view taken along section line 82A--82A of FIG. 82, and a bottom view of the shaft-locking support mechanism, respectively.

FIGS. 84 and 85 are side and top cross-sectional views of the shaft-locking mechanism employing an alternative shaft lock configuration.

FIG. 86 is a perspective view of the alternative shaft lock of FIGS. 84, 85.

FIGS. 87 and 88 are exploded perspective and cross-sectional views respectively of a handle mechanism of the stabilizing means.

FIG. 89 is an exploded perspective view of a contact member of the stabilizing means.

FIG. 90 is a rear view of the contact member of FIGS. 76, 77 and 89.

FIG. 91 is a cross-sectional view of the contact member of FIG. 90 taken along section line 91--91.

DETAILED DESCRIPTION OF THE INVENTION

This invention is surgical instruments for stabilizing the beating heart and methods for their use. The means for stabilizing the beating heart are comprised of several alternative structures at least one component of which engages the surface of the heart to stabilize the beating heart during coronary surgery. The instruments provide the capability to exert and maintain a stabilizing force on the heart by contacting the heart with a component of the stabilizing means and by functionally fixing the position of the stabilizing means throughout the duration of a surgical procedure.

The instruments and methods of the invention are preferably used for stabilization of the beating heart during a minimally invasive coronary artery bypass graft (CABG) operation which has been specially developed to facilitate completion of an anastomosis, to a target coronary artery for example by the placement of a bypass graft or the connection of a source artery, without requiring cardiac arrest such as cardioplegia or fibrillation and without cardiopulmonary bypass (CPB). Although the means for stabilizing the beating heart can be applied in different surgical contexts, the dev