Surgical apparatus and method - Patent Review 6254532

Description Submit all comments and votes

FIELD OF THE INVENTION

The present invention relates to the field of surgical apparatus and method, such as may be used, for example, for cardiac surgery.

BACKGROUND OF THE INVENTION

Cardiac surgery includes heart surgeries that require extracorporeal circulation (ECC), that is, the assistance of the cardiopulmonary machine, and those surgeries that are performed directly on the beating heart and do not require ECC. The term "cardiac surgery" can include coronary artery bypass graft surgery (CABG) with ECC, CABG directly on a beating heart, minimally invasive direct coronary artery bypass surgery (MIDCAB), heart valve repair surgery or valve replacement surgery, and surgery to correct either an atrial septal wall or ventricular septal wall defect.

The term "cardiac devices" can include surgical apparatus and devices used during "cardiac surgery". The term "coronary organs includes the heart, the heart's arteries and veins, the surrounding tissue and vessels, in particular the mediastinum, the pericardium, the thymus, the pleura, and the space between the two lungs. In this document, unless otherwise stated, a reference to arterial surgery, or to a target artery, are intended to encompass reference to veins as well, under the general field of vascular surgery.

In recent years, the drive for cost effective surgery has intensified the need to develop surgical apparatus and medical approaches that keep healthcare costs manageable, while also allowing the treatment of older patients where economic justification may previously have been deemed marginal. Surgical apparatus that improves the efficiency of surgeons while reducing operating times, and improves the efficacy of the surgical intervention is desirable.

The recent interest in and search for less invasive surgery has placed emphasis on cardiac surgery as well. A feature of heart surgery is that the beating motion of the heart tends to complicate the delicate surgical intervention.

Heart surgeries have been performed with the support of a cardio-pulmonary machine, whereby the patient's blood was oxygenated outside the body, through extracorporeal circulation (ECC). This permits coronary operations on the arrested heart, meaning that a surgeon can manipulate and operate on a still heart. During traditional CABG surgery, this enables the surgeon to position the heart for best access to the target artery, requiring grafting.

ECC is highly invasive, particularly in coronary artery bypass graft (CABG), valvular surgery, and repair of atrial and ventricular septal wall defect. The advantages offered with ECC have been offset by the morbidity (complications) and mortality related to the ECC itself. The inflammatory response, as well as the systemic microembolisms generated by ECC, induce to some extent a dysfunctional state of the brain, lungs, and kidneys, which tends to increase with the aging of the patient. As a result, alternate CABG procedures that do not rely on the very invasive use of ECC offer distinct advantages.

Canadian patent application 2,216,893 of Cartier and Paolitto, describes apparatus for performing coronary surgery without the very invasive cardio-pulmonary machine. Canadian patent application 2,216,893 also describes surgical apparatus having "coarse" and "fine" adjustments to permit a contacting member to be placed relatively accurately in a large number of positions and orientations within a surgical working volume. The "coarse" adjustment of the heart stabilizer is achieved through linear and angular displacements, which locate a first articulation assembly in the nature of a cylindrical post on a base retractor. The "fine" adjustment of the contacting member is achieved through linear and angular displacements of a second positioning rod with respect to the first positioning rod, through a second articulation assembly.

In some cardiac interventions, it is desirable to avoid or override the coarse and fine adjustment, and to allow the simultaneous setting of all the motion degrees of freedom available in both the spherical clamp and cylindrical post, through a single point control manipulation means, thereby linking all said degrees of freedom. It is also advantageous for the contacting member, through the surgical apparatus to serve to position and orient at least a portion of the coronary organ within surgical workspace.

To achieve complete revascularization in a single surgical procedure--that is, to revascularize or treat all surgically reconstructable diseased arteries in one intervention--it may be desirable to position and orient the beating heart to obtain access to the posterior artery beds, through the same heart contacting instrument which will eventually serve to stabilize that portion of the beating heart. As a result, a surgical approach and associated apparatus which can manipulate the beating heart without inducing tissue trauma and hemodynamic instability by allowing the surgeon to exploit all motion degrees of freedom of said apparatus, through a single point control manipulation means prior to securing the entire surgical set-up, is advantageous. It is also advantageous for that apparatus to be moveable to a position in which the heart can be stabilized and in which the surgeon's field of view remains substantially unobstructed.

Prior to rigid securing of entire surgical set-up, a surgical apparatus that allows its components to remain substantially attached (while keeping their relative positions and orientations), but free to rotate, slide, and pivot when movement loads are imposed by the surgeon through the manipulation means, offers distinct advantages.

In certain surgical interventions, it may be advantageous to limit the full range of motion available in one or more of the degrees of freedom of the surgical apparatus. It would be advantageous to have an adjustment means capable of setting a "bias"--a limited range of motion within the full range of motion of that specific degree of freedom that the apparatus could otherwise achieve, were the bias not present. Furthermore, it would be advantageous to have a surgical apparatus which allows the set bias to be re-adjusted to a new setting or overridden entirely, without disengaging the constituent components used to achieve said bias, or disengage a part of the surgical set-up.

In surgical interventions, especially in a beating heart approach, where the risk of inducing heart tissue trauma is present, it is advantageous to have a surgical apparatus which enhances the sensitivity of the surgeon to the loads imposed by the contacting means on the coronary organs.

In beating heart CABG, the use of pericardial sutures are sometimes used to help "verticalize" the heart in addition to the heart stabilizer devices described in Canadian patent application 2,216,893. It would be advantageous to anchor these sutures to the base retractor or to structure outside the surgical workspace, without limiting the range of motion of the positioning means namely the articulated arm assembly, once said sutures have been set. This may tend to be beneficial in multi-vessel coronary revascularizations that require the resetting of the positioning means and at least a part of the surgical set-up, in subsequent grafting of different arteries.

In beating heart surgery, the pulsating effect of the heart on the stabilization apparatus over prolonged periods, can at times necessitate re-adjustment of the surgical set-up. In addition, the surgeon's need to vary the contact forces on the heart depending on the surgical intervention (i.e. grafting, incision, etc.), may occasionally require the re-orientation and re-positioning of the contacting means to ensure optimum stabilization during the entire surgery. Apparatus that allow easy and expedient repositioning and reorientation of the contacting means offer distinct advantages. This would be particularly so with features that facilitate use of the surgical apparatus by a person wearing surgical gloves.

It would also be advantageous to have an apparatus and method for encouraging the isolating and exposure of a target artery requiring anastomosis through the arterial window formed by the geometry of a coronary stabilizer. In beating heart surgery, the coronary stabilizer immobilizes or stabilizes a portion of the heart tissue, and consequently may tend to immobilize the target artery straddled by a coronary stabilizer. It is desirable for the target artery to be isolated and exposed in a manner that causes it to rest proudly through the arterial window of the coronary stabilizer, thereby facilitating the surgery. It would be advantageous to have a surgical apparatus of a design which may tend to reduce or minimize the amount of distortion, deflection, or restriction imposed to the underlying heart tissue, thereby tending to preserve the natural beating function of the heart under mechanical stabilization.

SUMMARY OF THE INVENTION

In an aspect of the invention there is a surgical articulation assembly. It has a first structural element having an engagement member for mating with a second structural element. The engagement member is operable in a partially engaged condition to limit a range of motion of the second structural element relative to the first structural element with respect to a first degree of freedom of motion, while permitting relative motion between the first and second elements with respect to another degree of freedom of motion. The engagement member is operable in a fully engaged condition to fix the position of the structural elements relative to each other.

In an additional feature of that aspect of the invention, the assembly includes a tightening member mounted to the engagement member. The tightening member is operable to tighten the engagement member to the partially engaged position. The tightening element is operable to lock the structural elements in a fixed position.

In another additional feature of that aspect of the invention, in the partially engaged condition the tightening member permits at least two degrees of freedom of motion between said first and second structural members. In still another feature of that aspect of the invention, in the partially engaged position the tightening member permits at least three degrees of freedom of motion between the first and second structural members. In a still further additional feature of that aspect of the invention, in the partially engaged condition the tightening member permits at least four degrees of freedom of motion between the first and second structural members. In yet another additional feature of that aspect of the innvention, in the partially engaged condition the tightening member permits at least five degrees of freedom of motion between the first and second structural members.

In another aspect of the invention, there is a surgical articulation assembly. It has a first arm, a second arm, and an articulation joint connecting said arms. The joint is engaged to said first arm. The joint has a clamp for mating engagement with said second arm. The joint and the second arm have mutually engageable indexing elements. The clamp is operable to engage the second arm in a partially tightened condition. In the partially tightened condition the indexing elements are mutually engaged to encourage the second arm to be restrained to a limited range of motion with respect to one degree of freedom of motion. In the partially tightened condition the second arm is free to move in a full range of motion with respect to at least one other degree of freedom of motion relative to the first arm. The clamp is operable to engage the second arm in a fully tightened condition to fix the second arm relative to the first arm.

In an additional feature of that aspect of the invention, the assembly is a surgical assembly. In still another additional feature of that aspect of the invention, the assembly is a surgical assembly, the second arm is a tissue stabilizing tool having a body contacting portion and a shaft portion rigidly mounted thereto and the shaft is engageable in the clamp and the clamp and shaft have features chosen from the set of (a) the indexing feature of the second arm includes at least one depression extending inwardly of the surface thereof; and the indexing feature of the clamp includes at least one protrusion for engaging the depression; and (b) the indexing feature of the second arm includes at least one protrusion extending outwardly of the surface thereof, and the indexing feature of the clamp includes at least one depression for engagement by the protrusion.

In an additional feature of that aspect of the invention, in the partially tightened condition the indexing feature of the shaft extends circumferentially thereabout to restrain longitudinal translation thereof relative to the clamp while permitting rotation about a longitudinal axis thereof relative to the clamp. In another additional feature of that aspect of the invention, one of the indexing features of the clamp or the second arm is biased to an engagement position and can deflect under an override force to permit motion outside the limited range of motion. In yet another additional feature of that aspect of the invention, one of the indexing features is a spring loaded detent.

In another aspect of the invention, there is a floating clamp assembly for governing the relationship of a first structural member to a second structural member. The clamp assembly has first and second frame members, one of the frame members being mounted in a floating relationship relative to the other. The frame members have first co-operating portions of a capture fitting for engaging a mating portion of the first structural member. The frame members have co-operating opposed jaw portions for engaging the second structural member. A retainer is mounted to limit the floating relationship between the frames and to maintain the first co-operating portions in a capture relationship with the mating portions of the first structural member. In a loosened condition of the clamp assembly, the jaw portions are biased to an engaged position relative to the second structural member by the retainer. The floating relationship permits the jaws to deflect to admit a portion of the second structural member. In a tightened condition of the clamp assembly the frame members co-operate to fix the position of the structural members relative to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made by way of example to the accompanying drawings, which show an apparatus according to the preferred embodiment of the present invention and in which:

FIG. 1 shows a perspective view of a surgical apparatus according to this invention;

FIG. 2A shows a perspective view illustrating an alternative surgical apparatus for coronary revascularization on a beating heart, without ECC to that shown in FIG. 1;

FIG. 2B shows a perspective view illustrating a working volume and degrees of freedom of motion of the surgical apparatus of FIG. 2A;

FIG. 3 is a perspective view of a detail of an articulation member and adjustment member of the surgical apparatus of FIG. 1;

FIG. 4 is an exploded view of the members of the surgical apparatus of FIG. 3;

FIG. 5 is a perspective view illustrating an alternative apparatus to the apparatus of FIG. 1;

FIG. 6 is an exploded view of the alternative apparatus of FIG. 5;

FIG. 7 is a perspective view of another alternative to the members of FIG. 3;

FIG. 8 is an exploded view of the alternative members of FIG. 7;

FIG. 9 is a perspective view of an alternative embodiment to the apparatus of FIG. 1;

FIG. 10 is a perspective view a further alternative embodiment to that of FIG. 1;

FIG. 11 is an exploded view of the embodiment of FIG. 10;

FIG. 12 is a perspective view of a still further alternative embodiment to that of FIG. 1;

FIG. 13 is an exploded view of the embodiment of FIG. 12;

FIG. 14 is a perspective view for defining geometric terminology applicable to the apparatus of FIGS. 1 to 13;

FIG. 15A shows a right hand example of a pull type heart stabilizer of the apparatus of FIG. 1;

FIG. 15B shows a left hand example of a pull type heart stabilizer of the apparatus of FIG. 1;

FIG. 15C shows a steeply handled push-type heart stabilizer for use in an apparatus similar to the apparatus of FIG. 1;

FIG. 15D shows a shallow angled push type stabilizer for use in an apparatus similar to the apparatus of FIG. 1;

FIG. 16A shows a heart stabilizer for use in the apparatus of FIG. 1 having a detachable handle;

FIG. 16B shows a detail of the stabilizer of FIG. 16A;

FIG. 16C shows an alternative securing device for the detachable handle of FIG. 16A;

FIG. 16D shows an alternative securing device for the detachable handle of FIG. 16A;

FIG. 16E shows a further alternative securing device for the detachable handle of FIG. 16A;

FIG. 17A shows an exploded view of an alternative articulated arm assembly for use in the apparatus of FIG. 1;

FIG. 17B shows a side view, in part section, of an alternative articulated arm assembly for use in the apparatus of FIG. 1;

FIG. 17C shows a side view of a further alternative articulated arm to that of FIG. 17B;

FIG. 17D shows a perspective view of part of a still further alternative articulated arm assembly to that of FIG. 17B;

FIG. 18A shows an exploded view of an alternative of a joint assembly of the articulated arm assembly of FIG. 17A;

FIG. 18B shows a side view of an element of the joint assembly of FIG. 18A;

FIG. 18C shows an end section of an alternative to the joint of FIG. 18B;

FIG. 18D shows a side view of an element of the joint of FIG. 18C;

FIG. 19A shows a section of a fitting of the apparatus of FIG. 1;

FIG. 19B shows an alternative to the fitting of FIG. 19A;

FIG. 19C shows a further alternative to the fitting of FIG. 19A;

FIG. 20A shows a perspective view of the fitting of FIG. 19C engaged to an adapted sternum retractor;

FIG. 20B shows a detail of the fitting of FIG. 20A;

FIG. 21 is a perspective view of surgical apparatus illustrating a slit-like feature in an alternative sternum retractor to that shown with the apparatus of FIG. 1;

FIG. 22 is a cross-sectional view of surgical apparatus illustrated in FIG. 21 in use;

FIG. 23 is a perspective view of an alternative embodiment of apparatus to that of FIG. 1;

FIG. 24A shows a side view of a steep angle push type coronary stabilizer for use in the apparatus of FIG. 1;

FIG. 24B is a plan view of the stabilizer of FIG. 24A;

FIG. 24C is a front view of the stabilizer of FIG. 24A;

FIG. 25A is a side view of a shallow angle push-type stabilizer for the apparatus of FIG. 1;

FIG. 25B is a plan view of the stabilizer of FIG. 25A;

FIG. 25C is a front view of the stabilizer of FIG. 25A;

FIG. 26A is a side view of a pull-type stabilizer for use in the apparatus of FIG. 1;

FIG. 26B is a plan view of the stabilizer of FIG. 26A;

FIG. 26C is a view of the stabilizer of FIG. 26B taken on arrows `26C`;

FIG. 26D is a view of the stabilizer of FIG. 26C taken on arrows `26D`;

FIG. 27A is a side view of a steep angled push type stabilizer for the apparatus of FIG. 1;

FIG. 27B is a plan view of the stabilizer of FIG. 27A;

FIG. 27C is a front view of the stabilizer of FIG. 27A;

FIG. 28A is a side view of another shallow angled stabilizer for the apparatus of FIG. 1;

FIG. 28B is a plan view of the stabilizer of FIG. 28A;

FIG. 28C is a front view of the stabilizer of FIG. 28A;

FIG. 29A is a side view of a shallow angled pull type stabilizer for the apparatus of FIG. 1;

FIG. 29B is a plan view of the stabilizer of FIG. 29A; and

FIG. 29C is a front view of the stabilizer of FIG. 29A.

DETAILED DESCRIPTION OF THE INVENTION

The description that follows, and the embodiments described therein, are provided by way of illustration of an example, or examples, of particular embodiments of the principles of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention. In the description that follows, like parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order to depict more clearly certain features of the invention.

FIGS. 2A and 2B are provided for defining geometric terminology used throughout this description. A surgical apparatus is indicated generally as 50. It includes a sternum retractor 60 having a fixed, left hand structural member in the nature of a slotted channel member 62, a floating, right hand structural member 64 lying in a spaced apart, generally parallel relationship to member 62. One end of member 62 is rigidly mounted to a cross member in the nature of a yoke 66. Yoke 66 has a rack 68 along one side for engagement with a pinion 70. Pinion 70 is rotatably mounted to one end of right hand structural member 64 such that operation of the handle of pinion 70 engaging the teeth 71 of rack 68 will cause translation of member 64 relative to rack 68 in a direction indicated as the `x` direction, thereby adjusting the spacing between members 62 and 64. Left and right hand arcuate sternum retractor blades or clamps 72 and 74 depend from members 62 and 64 respectively, and, when members 62 and 64 are driven apart clamps 72 and 74 are operable to engage and separate left and right sides of a patient's rib cage. Each of members 62 and 64 has a rail, or trackway 76, 78 in the nature of a slot defined in the upper surface thereof.

A multiple degree of freedom articulated arm assembly is indicated generally as 80. It has a first, main, or shoulder joint indicated generally as 82 having a footing engaged in trackway 78. Shoulder joint 82 is also referred to as a cylindrical post, and is described in greater detail below. A first, or upper arm 84 extends from joint 82 to a second, intermediate, or elbow joint, indicated generally as 86, and a second, lower, or forearm 88. Elbow joint 86 is also referred to as the second articulation member, or as the spherical clamp. Several embodiments of spherical clamp elbow joints are described in greater detail below. A body engaging, tissue stabilizing member, or hand, indicated generally as 90 is rigidly mounted to the distal end of forearm 88.

Referring now to FIG. 2B, the flexibility and versatility of surgical apparatus 50 is described with reference to the following degrees of freedom:

S.: displacement of first articulation member along rails of retractor

R1: axial displacement along centerline of first positioning rod through first articulation member

R2: displacement along centerline of second positioning rod through second articulation member

.alpha.: rotation about centerline of first articulation member assembly

A1: angular displacement through rotation .alpha.

.beta.: angle between centerline of first positioning rod and centerline of articulation member assembly

P1: displacement along z axis achieved through rotation .beta.

.epsilon.: angle of tilt between (a) a plane containing the longitudinal axis of the second positioning rod and a horizontal axis perpendicular to the centerline of the first positioning rod, and (b) the centerline of the first positioning rod

.phi.: slew angle between the longitudinal axis of the second positioning rod and the horizontal axis perpendicular to the centerline of the first positioning rod, the slew angle lying in the plane containing both the longitudinal axis of the second positioning rod and the horizontal axis perpendicular to the centerline of the first positioning rod

A2: angular displacement of contacting means about the centerline of second positioning rod

Referring more specifically to FIG. 1, a surgical apparatus is indicated generally as 100. It has a fixed left-hand main structural member 101, a floating right-hand main structural member 102. A yoke 103 is rigidly connected to member 101. Yoke 103 has a rack 104 that interacts with pinion 105 of member 102. An articulated arm assembly is indicated generally as 106. It has a main, or shoulder joint 114 mounted to left hand member 101. A first or upper arm 116, is mounted in, and extends from, shoulder joint 114 to a second, intermediate, or elbow joint 118. A heart stabilizer tool is indicated generally as 120. It has a body contacting member, in the nature of a