US20040073301A1 - Less-invasive devices and methods for cardiac valve surgery - Google Patents

Abstract

Systems and methods are disclosed for performing less-invasive surgical procedures within the heart. A method for less-invasive repair or replacement of a cardiac valve comprises placing an instrument through an intercostal access port and through a penetration in a wall of a vessel in communication with the heart, advancing the instrument into the heart, and using the instrument to perform a surgical intervention on a cardiac valve in the heart under visualization through an intercostal access port The surgeons hands are kept outside of the chest during each step. The surgical intervention may comprise replacing the cardiac valve with a prosthetic valve, wherein the native valve is removed using a tissue removal instrument, the native valve annulus is sized with a specialized sizing device, a prosthetic valve is introduced through an intercostal access port and through the penetration in the vessel, and the prosthetic valve is secured at the native valve position, all using instruments positioned through intercostal access ports without placing the hands inside the chest. Systems and devices for performing these procedures are also disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of co-pending application Ser. No. 08/594,870, filed Jan. 31, 1996, which is a continuation-in-part of Ser. No. 08/485,600, which is a continuation-in-part of Ser. No. 08/281,962, now abandoned, which is a continuation-in-part of Ser. No. 08/163,241, now U.S. Pat. No. 5,571,215, which is a continuation-in-part of Ser. No. 08/023,778, now U.S. Pat. No. 5,452,733. This application is also a continuation-in-part of Ser. No. 08/486,941, now U.S. Pat. No. 5,799,661. The complete disclosure of each of the above-referenced applications is incorporated herein by reference for all purposes.[0001]
FIELD OF THE INVENTION
• The present invention relates generally to surgical instruments, and more specifically, to surgical instruments for less-invasive surgery of the heart and great vessels, especially instruments for repair and replacement of heart valves.[0002]
BACKGROUND OF THE INVENTION
• The present invention is directed to devices and techniques for the surgical treatment of heart valve disease, and particularly aortic valve disease. The aortic valve separates the left ventricle of the heart from the aorta, which carries oxygenated blood to the arterial system. Normally, when the left ventricle contracts during systole, the aortic valve opens to allow blood to flow into the aorta. During diastole, when the left ventricle returns to its uncontracted state, the aortic valve closes to prevent blood from flowing from the aorta back into the heart.[0003]
• In aortic valve disease, the aortic valve is compromised due to calcification of the valve leaflets, congenital deformation of the valve, or other conditions such that the valve does not completely open or close normally. As a result, the valve restricts blood flow out of the heart during systole, or the valve allows blood flow back into the heart during diastole. If the condition becomes sufficiently severe, surgical treatment is frequently required.[0004]
• Various surgical techniques have been used to repair aortic valves. In conventional “open-chest” approaches, a large opening is formed in the chest—known as a sternotomy or thoracotomy—the patient's heart is arrested while circulation is supported by a cardiopulmonary bypass system, an incision is formed in the aorta, and instruments are then used to decalcify the valve, to separate valve leaflets which are fused together, or to constrict the annulus of an enlarged valve. Less-invasive approaches to valve repair have also been proposed. Balloon valvuloplasty, for example, involves the use of a balloon catheter threaded from a peripheral artery into the aorta, and expansion of a balloon within the calcified aortic valve to separate the valve leaflets while the heart remains beating. Unfortunately, aortic valve repair techniques have not had long-lasting success in preventing recurrence of the disease, and eventual replacement of the valve is frequently required.[0005]
• The most widely-accepted surgical technique for the treatment of severe aortic valve disease is aortic valve replacement. In aortic valve replacement surgery, the diseased aortic valve is replaced with a prosthetic valve, homograft, allograft, or other type of replacement valve. Conventional aortic valve replacement techniques require a sternotomy or thoracotomy to be formed so as to provide access into and visualization of the chest cavity. The patient is placed on cardiopulmonary bypass, and the heart is stopped using an aortic cross-clamp to block blood flow through the aorta while a cardioplegic fluid is injected into the aorta upstream of the cross-xclamp or into the coronary sinus on the venous side of the heart. An incision is then made in the ascending aorta near the aortic valve, and the native valve leaflets are removed using surgical scissors inserted through the aortic incision. Specialized instruments may also be used to debride the valve annulus. A replacement valve is then sutured in place at the native valve position.[0006]
• While aortic valve replacement is frequently effective in treating aortic valve disease and can add ten or more years to the life of a patient having the disease, the procedure also suffers from significant drawbacks surrounding the invasiveness and trauma of the surgery. The large thoracotomy required by the procedure is highly invasive, produces a great deal of pain, heightens the risk of infection and other complications, increases costs. and lengthens hospital stay considerably.[0007]
• What is needed, therefore, are devices and techniques for the surgical treatment of aortic valve disease, especially for performing aortic valve replacement, which do not suffer from the drawbacks of conventional open-chest aortic valve surgery. Most desirably, the devices and techniques should obviate the need for a sternotomy and minimize the size of any necessary thoracic incisions to eliminate the pain, trauma, risks, costs, and lengthy recovery time associated with conventional aortic valve surgery. At the same time, the devices and techniques should facilitate replacement of a diseased aortic valve with the same types of replacement valves which currently enjoy wide acceptance for aortic valve replacement, including mechanical valves, bioprosthetic valves, homografts, allografts, and others.[0008]
SUMMARY OF THE INVENTION
• The invention provides devices and methods for performing heart valve surgery which eliminate the need for a median sternotomy or other type of thoracotomy. The devices and methods are particularly advantageous in that they facilitate surgical repair or replacement of a heart valve in a manner analogous to the widely-accepted surgical techniques used in open-chest valve repair or replacement, yet without the invasiveness, pain, risks, and recovery time of conventional techniques. Advantageously, the devices and methods facilitate replacement of a diseased heart valve using various types of commercially-available replacement valves with proven safety and effectiveness. The devices and methods of the invention are perhaps most useful for the repair and replacement of the aortic valve, but may be used for the surgical treatment of any of the valves of the heart, as well as in other surgical procedures within the heart and great vessels of the thorax.[0009]
• In one aspect of the invention, a method is provided for accessing an internal chamber of a patient's heart through a vessel in fluid communication with the chamber. The method includes visualizing the vessel through a percutaneous access port between two adjacent ribs. An instrument is positioned into an inner lumen of the vessel through a penetration in a wall of the vessel. The proximal end of the instrument extends out of the patient's chest through a percutaneous access port between the ribs, and the proximal end of the instrument is then manipulated to position the distal end of the instrument through the vessel and into the internal chamber of the heart. With the instrument within the internal chamber. various types of inspection, diagnostic and interventional procedures may then be performed. All manipulations of the instrument are performed with the surgeon's hands outside of the patient's chest, and none of the ribs or the sternum are cut or removed during each step. Preferably, in fact, none of the ribs or the sternum are significantly retracted from their natural undeflected positions during the procedure. Visualization is accomplished either by looking directly into the chest through an access port between the ribs, by introducing a thoracoscope through such an access port and viewing a video image of the vessel and heart on a monitor, or by using other available less-invasive visualization devices.[0010]
• In a preferred embodiment, the vessel is the aorta, the chamber is the left ventricle of the heart, and the distal end of the instrument is positioned into the aorta, through the aortic valve, and into the left ventricle. The instrument may then be used to perform a procedure in the heart or on the aortic valve itself. For example, the instrument could be used for repairing a diseased aortic valve, and may comprise a debridement device for removing calcium from the valve annulus or leaflets, a scissors for incising the leaflet commissures to separate the leaflets, a cutting device for resecting the valve leaflets, or a needle driver for applying a suture to the valve annulus to reduce the diameter of the valve.[0011]
• In a particularly preferred embodiment, the instrument is used in the replacement of a diseased aortic valve. The instrument may be a scissors, rongeur, knife or other cutting instrument for removing the native valve leaflets, or a needle driver or other device for applying sutures to the native valve annulus which are used to secure a replacement valve at the aortic valve position. The instrument could alternatively comprise a valve sizing device for measuring the size of the native valve annulus, or a valve delivery instrument for positioning a replacement valve at the aortic valve position. In any case, the instrument extends from the left ventricle out of the chest through a percutaneous access port between two ribs, and is manipulated entirely from outside of the chest.[0012]
• As another alternative, the instrument may comprise any of a variety of devices for performing diagnostic or interventional procedures within the heart, such as an angioscope or other endoscopic visualization device, an electrophysiological mapping or ablation device. or a laser for transmyocardial revascularization. Additionally, the instrument could be used to repair or replace other valves of the heart. For example, the mitral valve could be repaired or replaced by positioning the instrument through the aorta and left ventricle to the mitral position (and through the mitral valve into the left atrium if necessary). Or, an instrument could be positioned through the superior vena cava or the inferior vena cava into the right atrium to perform a procedure on the right side of the heart, including repair or replacement of the tricuspid valve between the right atrium and right ventricle, or repair or replacement of the pulmonary valve between the right ventricle and the pulmonary artery. Various other procedures may also be performed according to the method of the invention, including pulmonary thrombectomy, the Cox “maze” procedure for treatment of atrial fibrillation, and repair of congenital defects such as atrial and ventricular septal defects or patent ductus arteriosus.[0013]
• In many of the procedures which may be performed using the methods of the invention, the patient is placed on cardiopulmonary bypass and the heart is arrested. First, general anesthesia is administered. To establish cardiopulmonary bypass, an arterial cannula is placed into a peripheral artery, usually a femoral artery, and a venous cannula is placed in a peripheral vein, usually a femoral vein. The arterial and venous cannulae are connected to a cardiopulmonary bypass pump and oxygenator, allowing deoxygenated blood to be withdrawn from the venous system through the venous cannula, oxygenated, and then pumped back into the patient's arterial system through the arterial cannula.[0014]
• The heart may then be arrested in any of several ways. In an endovascular technique, an aortic catheter is introduced into a peripheral artery selected from among the femoral, brachial or subclavian arteries. The aortic catheter is advanced transluminally into the ascending aorta, and an expandable member such as a balloon is expanded in the ascending aorta to block blood flow through the aorta A cardioplegic fluid is then delivered into the ascending aorta upstream of the expandable member so as to perfuse the myocardium via the coronary arteries. Alternatively, a thoracoscopic aortic occlusion device may be used to arrest the heart. The thoracoscopic aortic occlusion device may be an external clamp positionable through a percutaneous access port between two ribs and around the exterior of the aorta, the clamp being movable between an open position and a closed position in which it clamps the aorta to occlude the aortic lumen. A cardioplegic fluid is then delivered into the aorta upstream of the clamp, either through a cannula penetrating the aortic wall and extending out of the chest through an intercostal access port, or through an endovascular catheter extending into the ascending aorta from a peripheral artery. The thoracoscopic aortic occlusion device may alternatively comprise a shaft having an expandable member such as a balloon mounted to its distal end which is configured to be introduced into the aorta through a small incision or puncture in the aortic wall. The expandable member may be expanded within the aorta to occlude the aortic lumen, and a cardioplegic fluid then delivered upstream of the clamp through either a thoracoscopic cannula or endovascular catheter.[0015]
• In many cases, in order to maintain cardioplegic arrest, it will be desirable to deliver cardioplegic fluid to the myocardium in a retrograde manner via the coronary sinus instead of or in addition to antegrade delivery from the ascending aorta In these cases, an endovascular catheter is introduced transluminally into the coronary sinus, which drains into the right atrium of the heart, from a peripheral vein such as the femoral, subclavian or internal jugular vein. The endovascular catheter preferably has a balloon or other occluding member on its distal end for occluding the coronary sinus during delivery of cardioplegic fluid. Usually, the occluding member is expanded while cardioplegic fluid is delivered, then contracted to allow fluid to drain into the right side of the heart from the capillary beds feeding the myocardium.[0016]
• With the heart arrested and circulation of blood supported by cardiopulmonary bypass, the patient is prepared for a surgical procedure conducted in accordance with the principles of the invention. One such procedure is replacement of the aortic valve. In a method of aortic valve replacement according to the invention, a valve prosthesis is positioned through a percutaneous access port between two adjacent ribs and through an incision in a wall of the aorta using a first instrument. The valve prosthesis is then attached at the aortic valve position between the left ventricle and the aorta using at least a second instrument. All instruments used in the procedure are manipulated only from outside of the chest, and neither the ribs nor the sternum are cut or removed during the procedure. Visualization of the vessel and heart is accomplished, as described above, by direct vision through an access port, or using a thoracoscope or other minimally-invasive visualization device.[0017]
• In a preferred embodiment, the first instrument comprises a delivery handle which is coupled to the valve prosthesis, or to a holder on which the valve prosthesis is mounted. The delivery handle is configured to allow the valve prosthesis to be introduced into the chest through the percutaneous access port and has a length selected to reach the aortic valve position from outside of the chest. Usually, the valve prosthesis is introduced from the first, second, third, or fourth intercostal space on the anterior side of the chest, and the delivery handle is at least about 20 cm in length. In a specific embodiment, the valve prosthesis is movably coupled to the delivery handle such that it may be positioned through the access port between the ribs in a first orientation, then re-oriented within the chest relative to the delivery handle into a second orientation suitable for attachment at the aortic valve position. Preferably, the delivery handle has an actuator on its proximal end to allow the valve prosthesis to be reoriented by moving the actuator outside of the patient's chest[0018]
• The valve prosthesis is preferably coupled to the delivery handle in such a way that it may be positioned through an intercostal space without removing or retracting the ribs significantly. In a preferred embodiment, the valve prosthesis is mounted such that an axis extending axially through the middle of the sewing ring of the valve prosthesis is approximately perpendicular to the longitudinal axis of the delivery handle. In this way, the profile of the valve prosthesis and delivery handle in a plane perpendicular to the longitudinal axis of the delivery handle is minimized. For some types of replacement valves, however, even in this orientation, the profile of the valve and handle will be large enough that some minor retraction of the adjacent ribs may be required to allow the valve to be introduced into the chest without risking damage to the valve.[0019]
• The percutaneous access port through which the valve prosthesis is positioned may comprise a puncture or incision through the chest wall between the ribs which does not involve cutting or removing the ribs or the sternum adjacent to the incision. Preferably, no significant retraction or displacement of the ribs or sternum will be necessary. In most cases, the tissue adjacent to the access port will need to be retracted or separated to provide an opening into the chest which will not interfere with introduction of the valve prosthesis and through which the surgeon may view the chest cavity. For this purpose, the invention provides a retraction device particularly well-suited for aortic valve replacement. In a preferred embodiment, the retraction device comprises a cannula having a distal end suitable for placement between the ribs into the chest. a proximal end, and a passage therebetween configured to allow the valve prosthesis to be easily passed through it. In a preferred configuration, the passage in the cannula has a cross-sectional height which is substantially greater than its cross-sectional width, preferably at least about 1.5 times the cross-sectional width. In this way, the cross-sectional height may be large enough to accommodate the outer diameter of the valve prosthesis in the passage, while the cross-sectional width is small enough to fit between the ribs without significant retraction (yet being large enough to accommodate the height of the valve prosthesis when mounted to the delivery handle).[0020]
• If a replacement valve having a larger profile is to be used requiring some minor retraction of ribs, the retraction device of the invention may be adjustable in width to provide a slightly larger passage into the chest while the valve is introduced, deflecting the ribs adjacent to the access port as needed. Once the replacement valve is within the chest cavity, the retraction device may be returned to a smaller width in which the ribs are in their natural, undeflected positions for the remainder of the procedure.[0021]
• The retraction device of the invention may further include a suture organizer mounted to it for arranging the sutures used to secure the valve prosthesis in the aortic valve position. In a preferred embodiment, the suture organizer is mounted to the proximal end of the cannula through which the valve prosthesis is positioned, whereby a plurality of sutures may be drawn out of the chest cavity through the passage in the cannula and placed in spaced-apart locations on the suture organizer. The suture organizer may comprise, for example, a ring having a plurality of radial slots arranged about its perimeter each of which is configured to receive and retain a suture thread.[0022]
• Usually, the native valve leaflets are excised from the native annulus and any calcium or other debris on the annulus is removed before a replacement valve is implanted. To remove the valve leaflets, thoracoscopic scissors and forceps may be introduced through a percutaneous access port and used to cut the leaflets from the annulus. Specialized thoracoscopic debridement devices, such as rongeurs having an inner lumen through which suction may be applied, are then used to cut away calcific deposits and other undesirable matter from the surface of the valve annulus. During this process a filter or trap may be placed through the aortic valve into the left ventricle to catch any debris which may be released.[0023]
• In most cases, the native valve annulus must be measured to ascertain the appropriate size of the valve prosthesis to be used. This is accomplished by utilizing a specialized valve sizing device which may be introduced through a percutaneous access port and positioned adjacent to or advanced through the native annulus. The sizing device preferably includes an elongated handle with a sizing disk of a known size at its distal end which may be compared to or positioned within the native annulus. The sizing disk may be adjustable in diameter to measure a range of sizes, may include markings for visual identification of the size of the annulus, or may be interchangeable with larger and smaller sizing disks to allow multiple sizes to be tried until the proper one is found. The sizing disk is mounted to the distal end of the handle in such a way as to be positionable into the chest without retracting or removing ribs, and is preferably pivotably attached to the handle so as to be movable into a low profile orientation for introduction, or is collapsible for introduction and then expandable for sizing the valve annulus.[0024]
• A variety of different replacement valves may be implanted using the devices and methods of the invention, including mechanical prostheses, bioprostheses, homografts and allografts. Advantageously, the invention facilitates the use of many of the clinically-proven replacement valves currently used in open-chest valve replacement without modification of these valves and without the need for removal or significant retraction of the ribs.[0025]
• The replacement valve may be secured at the native valve position in various ways, but is preferably secured using sutures. The sutures are applied to the aortic valve annulus using elongated thoracoscopic needle drivers or other known types of thoracoscopic suture placement devices positioned through a percutaneous access port. Usually, a plurality of sutures are applied to the annulus, drawn out of the chest cavity, and then applied to the sewing ring of the valve prosthesis outside of the chest. The valve prosthesis is then slid along the sutures through the access port and placed against the native valve annulus using the delivery handle or other appropriate thoracoscopic instrument. A knot is formed in each suture outside of the chest, and the knot is pushed along the suture through the access port and against the sewing ring of the valve prosthesis using a thoracoscopic knot pusher. The free ends of the suture are then trimmed using thoracoscopic scissors.[0026]
• For securing bioprosthetic valves and other types of replacement valves, it may be desirable to use a single suture to form a running stitch between the sewing ring and the native valve annulus. In these cases, with the valve held in place at or near the aortic position using the delivery handle, thoracoscopic needle drivers may be positioned through an access port and used to drive a needle alternately between the native annulus and the sewing ring of the replacement valve. The suture is then tied off and trimmed using thoracoscopic instruments.[0027]
• Once the replacement valve has been secured at the aortic valve position, the aortic incision must be closed. Thoracoscopic needle drivers are introduced through a percutaneous access port and used to drive a suture back and forth across the incision from end to end in a running stitch. The suture is then tied off and trimmed.[0028]
• With the aortic incision closed, the patient's heart is restarted by removing the aortic occlusion device, whether an external clamp, endovascular aortic occlusion catheter, or other means, from the ascending aorta. If placed through a puncture in a wall of the aorta, the puncture is closed with a purse- string suture or running stitch using thoracoscopic needle drivers. Warm oxygenated blood delivered to the arterial system by the arterial cannula is thereby allowed to flow into the ascending aorta and to perfuse the myocardium via the coronary arteries. Normal heartbeat will ordinarily resume spontaneously. If not, electrical defibrillation may be administered. Once normal heartbeat has resumed, any retractors, trocars, or other devices in the percutaneous access ports are removed, and chest incisions are closed with sutures or adhesive strips. The patient is gradually weaned from cardiopulmonary bypass, all arterial and venous cannulae are removed, and arterial and venous punctures are closed. The patient is then recovered from anesthesia.[0029]
• A further understanding of the nature and advantages of the invention will become apparent from the following detailed description taken in conjunction with the drawings.[0030]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is an anterior view of a patient's chest schematically illustrating an endovascular system for inducing cardioplegic arrest and establishing cardiopulmonary bypass according to the invention.[0031]
• FIG. 2 is a close-up view of a patient's heart and aorta showing the placement of an endoaortic catheter in the system of FIG. 1.[0032]
• FIG. 3 is an anterior view of a patient's chest schematically illustrating a first embodiment of a thoracoscopic system for inducing cardioplegic arrest and establishing cardiopulmonary bypass according to the invention.[0033]
• FIG. 3A is an anterior view of a patient's chest schematically illustrating a technique of gaining access to the aorta according to the invention.[0034]
• FIG. 4 is a close-up view of a patient's heart and aorta illustrating the placement of a thoracoscopic balloon cannula in the system of FIG. 3.[0035]
• FIG. 5 is an anterior view of a patient's chest schematically illustrating a second embodiment of a thoracoscopic system for inducing cardioplegic arrest and establishing cardiopulmonary bypass according to the invention.[0036]
• FIG. 6 is a close-up view of a patient's heart and aorta illustrating the placement of a thoracoscopic clamp in the system of FIG. 5.[0037]
• FIG. 7 is an anterior view of a patient's chest schematically illustrating a third embodiment of a thoracoscopic system for inducing cardioplegic arrest and establishing cardiopulmonary bypass according to the invention.[0038]
• FIG. 8 is a close-up view of a patient's heart and aorta illustrating the placement of a detachable thoracoscopic clamp and applicator in the system of FIG. 7.[0039]
• FIG. 9 is an anterior view of a patient's chest schematically illustrating the formation of an aortotomy in the ascending aorta according to the invention.[0040]
• FIG. 10 is a close-up view of a patient's heart and aorta illustrating the formation of an aortotomy in the ascending aorta according to the invention.[0041]
• FIG. 11 is an anterior view of a patient's chest schematically illustrating retraction of the aortotomy according to the invention.[0042]
• FIG. 12 is a view of the aortotomy and the aortic valve through an oval-shaped access port placed in an intercostal space in the patient's chest, illustrating the placement of sutures for retraction of the aortotomy according to the invention.[0043]
• FIG. 13 is a view of the aortotomy and the aortic valve through an oval-shaped access port placed in an intercostal space in the patient's chest, illustrating the removal of the aortic valve leaflets according to the invention.[0044]
• FIG. 14 is a close-up partial cross-section of the left ventricle of the heart and the aorta showing a catcher placed in the left ventricle to catch pieces of valve leaflet and debris removed from the native valve annulus according to the invention.[0045]
• FIG. 15 is a view of the aortotomy and the aortic valve through an oval-shaped access port placed in an intercostal space in the patient's chest, illustrating the removal of calcific and fibrous material from the native valve annulus according to the invention.[0046]
• FIG. 16 is a transverse cross-sectional view of a portion of the patient's chest and heart illustrating the use of a valve sizing device for sizing the native valve annulus according to the invention.[0047]
• FIG. 17 is a transverse cross-sectional view of a portion of the patient's chest and heart illustrating the placement of sutures in the native valve annulus according to the invention.[0048]
• FIG. 18 is a view of the aortotomy and the aortic valve through an oval-shaped access port placed in an intercostal space in the patient's chest, illustrating the placement of sutures in the native valve annulus according to the invention.[0049]
• FIG. 19 right lateral elevational view of the patient's chest illustrating the placement of sutures through a prosthetic valve according to the invention.[0050]
• FIG. 20 is a transverse cross-sectional view of a portion of the patient's chest and heart illustrating the positioning of a prosthetic valve into the chest through an access port according to the invention.[0051]
• FIG. 21 is a right lateral elevational view of the patient's chest with a portion of the chest cut-away illustrating the placement of the prosthetic valve at the native valve position in the heart.[0052]
• FIG. 22 is a view of the aortotomy and the aortic valve through an oval-shaped access port placed in an intercostal space in the patient's chest, illustrating the tying and trimming of sutures to secure a prosthetic valve in the heart according to the invention.[0053]
• FIG. 23 is a view of the aortotomy and the aortic valve through an oval-shaped access port placed in an intercostal space in the patient's chest, illustrating the closure of the aortotomy according to the invention.[0054]
• FIG. 24 is a perspective view of an alternative embodiment of a delivery handle according to the invention holding an element schematically representing a valve sizing disk or prosthetic valve.[0055]
• FIG. 25 is a perspective view of the delivery handle of FIG. 24 illustrating the element pivoted into an orientation suitable for positioning through an intercostal access port.[0056]
• FIG. 26 is a side cross-sectional view of the delivery handle of FIGS. 24 and 25.[0057]
• FIG. 27 is a perspective view of an additional embodiment of an access port through which a prosthetic valve may be positioned into the chest according to the invention.[0058]
• FIG. 28 is a perspective view of the access port of FIG. 27 showing deployment of a retention element for retaining the access port in the chest wall.[0059]
• FIG. 29 is a perspective assembly view of the access port of FIGS.[0060]27-28.
• FIG. 30 is a perspective view of an obturator for use in conjunction with the access port of FIGS.[0061]27-29.
• FIGS.[0062]31A-31B are side cross-sectional views of the obturator of FIG. 30 illustrating the actuation a means for retracting the retention means of the access port of FIGS.27-29.
• FIG. 32 is a perspective view of the delivery handle of FIGS.[0063]24-26 including an alternative embodiment of a valve holder according to the invention.
• FIG. 33A is a side assembly view of a distal portion of the delivery handle and valve holder of FIG. 32.[0064]
• FIG. 33B is an end view of the valve holder of FIG. 32.[0065]
• FIG. 34 is a perspective view of a bileaflet mechanical heart valve useful in conjunction with the devices and methods of the invention.[0066]
• FIG. 35 is a perspective view of a further embodiment of a valve holder according to the invention holding the bileaflet mechanical heart valve of FIG. 34.[0067]
• FIGS.[0068]36A-36C are side, bottom, and proximal end views, respectively of the valve holder of FIG. 35.
• FIG. 37 is a perspective view of an access port and illumination device constructed in accordance with the principles of the invention.[0069]
• FIGS.[0070]38-40 are cross-sections taken along the lines38-38,39-39 and40-40, respectively, of FIG. 37.
• FIG. 41 is a transverse cross-section of an alternative embodiment of an access port and illumination device according to the invention.[0071]
• FIG. 42A is a front view of an alternative embodiment of an access port having a channel through which an illumination or visualization device may be inserted.[0072]
• FIG. 42B is a transverse cross-section taken along[0073]line42B-42B of FIG. 42A.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
• Specific embodiments of the devices and methods of the invention will now be described in connection with aortic valve replacement procedures. However, it will be understood to those of ordinary skill in the art that a wide variety of procedures may be performed on a variety of body structures without departing from the scope of the invention. These include, in addition to surgery of the aortic valve via the aorta, interventions in the coronary arteries, left ventricle, mitral valve, left atrium, or pulmonary vein via the aorta, interventions in the right atrium, tricuspid valve, right ventricle, pulmonary valve or pulmonary artery via the superior vena cava or inferior vena cava, as well as interventions in various other organs via vessels in communication with those organs. The types of interventions which can be performed include not only aortic valve repair and replacement, but catheter interventions in the coronaries such as angioplasty, atherectomy, stent placement or endoarterectomy, electrophysiological interventions within the heart such as mapping and ablation, transmyocardial revascularization using a laser placed within the heart, repair of septal defects and patent ductus arteriosus using patch placement or other defect closure devices placed in the right or left chambers of the heart, repair or replacement of the mitral, tricuspid or pulmonary valve including placement of annuloplasty rings and prosthetic valves, reattachment of chordae tendonae, commissurotomy, and quadrangular resection, incision of the atrial or ventricular wall for the performance of a Cox maze procedure in the treatment of atrial fibrillation, and other procedures. The principles of the invention will apply to the performance of these procedures in much the same way as to the performance of aortic valve replacement, which is now described with reference to FIGS.[0074]1-36.
• The patient is first prepared for aortic valve surgery by putting the patient under general anesthesia, establishing cardiopulmonary bypass (CPB) and inducing cardioplegic arrest. General anesthesia is induced in a conventional manner. A preferred technique for accomplishing CPB and cardioplegic arrest which does not require a sternotomy, thoracotomy, or other opening in the patient's chest is illustrated in FIG. 1. Additional aspects of the systems and methods for inducing cardioplegic arrest described here may be found in patent application Ser. Nos. 08/1282,192, filed Jul. 28, 1994, now U.S. Pat. Nos. 5,584,803 and 08/486,216, filed Jun. 7, 1995, now U.S. Pat. No. 5,766,151, the complete disclosures of which are hereby incorporated herein by reference.[0075]
• A[0076]cardiopulmonary bypass system20 includes avenous cannula22 which is placed in afemoral vein24 in the groin area or in another peripheral vein such as an internal jugular vein or subclavian vein, located in the neck. While illustrated in a shorter configuration, the venous cannula may be long enough to extend from the femoral vein into the inferior vena cava, into the right atrium of the heart or through the right atrium into the superior vena cava. The system also includes anarterial return cannula26 placed in afemoral artery28 or in another peripheral artery such as the subclavian or brachial artery in the neck or armpit. Thearterial return cannula26 is generally long enough so that it extends sufficiently into the femoral artery to avoid backing out of the artery but as short as possible to reduce damage to blood delivered through the arterial return cannula. Bothvenous cannula22 andarterial return cannula26 are configured to be placed into the femoral vein and femoral artery, respectively, either by surgical cut-down, or by a percutaneous technique such as the Seldinger technique.
• [0077]Venous cannula22 andarterial return cannula26 are connected to a CPB pump andoxygenator30 of well-known construction. CPB pump andoxygenator30 oxygenates the deoxygenated blood withdrawn from the patient's venous system throughvenous cannula22, and pumps the oxygenated blood back into the patient's arterial system viaarterial return cannula26. In this way, circulation and re-oxygenation of the patient's blood may be maintained while the heart is temporarily arrested.
• Cardioplegic arrest may be induced using any of several techniques. One preferred technique is illustrated in FIGS. 1 and 2. In this technique, an[0078]endoaortic catheter32 is introduced by surgical cut-down or by a percutaneous technique into a peripheral artery, which may be thefemoral artery34 as illustrated, or a brachial or subclavian artery.Endoaortic catheter32 is configured to be advanced transluminally, usually over a guidewire (not shown), fromfemoral artery34 into the aorta until itsdistal end36 is positioned in the ascendingaorta38 between the coronary ostia (not shown) just downstream of the aortic valve and thebrachiocephalic artery40.Endoaortic catheter32 has anexpandable member42 mounted near itsdistal end36 which, as shown in FIG. 2, is configured to expand into sealing engagement with the inner wall of the ascendingaorta38 to block blood flow through the aorta without occluding eitherbrachiocephalic artery40 or the coronary ostia. In a preferred embodiment,expandable member42 is an elastomeric balloon in communication with aninflation lumen43 extending throughendoaortic catheter32 to a delivery device such assyringe46 for delivering an inflation fluid such as saline or radio-opaque contrast solution to expandexpandable member42 until completely occluding the aorta. The elastomeric balloon preferably is short in the axial direction, being disc-shaped (a short cylinder), donut-shaped (toroidal), ellipsoidal, or other shortened shape to minimize the amount of the ascending aorta which is occupied by the balloon so that the surgeon has the maximum room to work upstream of the balloon. In one embodiment,expandable member42 has an axial length between its proximal and distal ends of about 1-40 mm, preferably about 1-20 mm, and an expanded outer diameter in the radial direction of about 10 to 60 mm, preferably about 30-40 mm.
• In a particularly preferred embodiment,[0079]arterial return cannula26 includes an additional hemostatic port (not shown) at its proximal end that allowsendoaortic catheter32 to be slidably positioned through the blood return lumen of the arterial return cannula. Arterial return cannulae having such a configuration are disclosed in copending application Ser. No. 08/282,192, filed Jul. 28, 1994, now U.S. Pat. No. 5,584,803, which is incorporated herein by reference.
• With[0080]expandable member42 occluding the ascendingaorta38, a cardioplegic fluid is delivered from acardioplegic fluid supply48 through adelivery lumen44 inendoaortic catheter32 and aport51 at itsdistal end36 into the ascending aorta distal toexpandable member42 so that the cardioplegic fluid flows into the coronary arteries to perfuse the myocardium. The cardioplegic fluid preferably includes a cardioplegic agent such as potassium chloride mixed with blood and cooled to a low temperature, e.g. 5-20° C. Upon perfusion of the myocardium with cardioplegic fluid, heart contractions will quickly cease. Circulation of oxygenated blood to organs and tissues other than the heart is maintained bycardiopulmonary bypass system20.Expandable member42 prevents the oxygenated blood delivered byarterial return cannula26 from reaching the coronary arteries, which would allow the blood to perfuse the myocardium and revive the heart.
• Periodically, it may be necessary to remove fluids from the ascending[0081]aorta38 during the procedure. Such fluids may be withdrawn throughdelivery lumen44 ofendoaortic catheter32 and diverted through avalve47 to a filter andrecovery system49, which removes impurities from the blood and directs the blood tocardiopulmonary bypass system20 where it is delivered back into the arterial system. Alternatively, a separate cardiotomy suction probe may be introduced through an access port and through the aortic wall to remove such fluids.Endoaortic catheter32 preferably also includes apressure port53 near itsdistal end36 in communication with a pressure lumen extending to the proximal end of the catheter where it may be connected to apressure measurement device50, allowing pressures in the ascending aorta distal toexpandable member42 to be monitored during the procedure.
• In addition to delivery of cardioplegic fluid in the “antegrade” manner via[0082]endoaortic catheter32 as just described, it is usually desirable to deliver cardioplegic fluid in a “retrograde” manner through the coronary sinus during the aortic valve replacement procedure. For this purpose, acoronary sinus catheter52 is placed into aperipheral vein54, preferably the internal jugular vein or subclavian vein in the neck, and advanced through the superior vena cava into the right atrium, where it is maneuvered into the coronary sinus (not illustrated).Coronary sinus catheter52 has a balloon or otherexpandable member58 near its distal end60 which may be expanded by means of asyringe62 to occlude the coronary sinus during fluid delivery. A delivery lumen (not pictured) extends through thecoronary sinus catheter52 to a port at its distal end60 to allow delivery of a cardioplegic fluid, which will usually be similar to that described above used in antegrade delivery.Coronary sinus catheter52 may also include a pressure port near distal end60 and a pressure lumen extending to its proximal end for monitoring pressure distal toexpandable member58. Other aspects of coronary sinus catheters and retrograde cardioplegia techniques useful in connection with the present invention are disclosed in copending application Ser. No. 08/372,741, filed Jan. 12, 1995, now U.S. Pat. No. 5,558,644, which is hereby incorporated herein by reference.
• In a preferred technique, after an initial infusion of cardioplegic fluid through[0083]endoaortic catheter32 to induce cardioplegic arrest, most subsequent infusions are performed retrograde throughcoronary sinus catheter52. To maintain cardioplegic arrest, cardioplegic fluid is preferably delivered in periodic infusions at, for example, 600 ml volumes delivered in about 120 to 180 seconds at 15 minute intervals. Between infusions,expandable member58 ofcoronary sinus catheter52 is preferably deflated to allow fluid to drain from the coronary sinus.
• In an alternative technique for inducing cardioplegic arrest, devices are introduced thoracoscopically through access ports between the ribs to occlude the ascending aorta and, optionally, to deliver cardioplegic fluid into the ascending aorta upstream of the occluded area. In these thoracoscopic techniques, the pericardium is first opened to expose the ascending aorta. As illustrated in FIG. 3A,[0084]several access ports71, such as trocar sleeves or other tubular cannulae, are placed in intercostal spaces I between ribs R. A thoracoscope73 of conventional construction and having avideo camera75 mounted to its proximal end may be placed through one ofaccess ports71 for visualizing the procedure, or the surgeon may look directly into the chest through one ofaccess ports71.Thoracoscopic scissors77 andgraspers79 are introduced throughaccess ports71 and used to create anincision81 approximately 4-10 cm in length in the anterior side of thepericardium83 overlying theaorta85 so that the ascendingaorta87 and upper anterior side of theheart89 are exposed.Thoracoscopic scissors77 andgraspers79 may have any of various well-known constructions, including those described in copending application Ser. No. 08/194,946, filed Feb. 14, 1994, now U.S. Pat. No. 5,501,698, which is hereby incorporated herein by reference.
• In a first embodiment of a thoracoscopic technique for arresting the heart, illustrated in FIGS.[0085]3-4, anexpandable member64 such as an elastomeric balloon is positioned in the ascendingaorta66 through a penetration in a wall of the aorta.Expandable member64 will be shaped and dimensioned to allow complete occlusion of ascendingaorta66 without blocking blood flow into thebrachiocephalic artery78 or the coronary ostia. Additionally,expandable member64 will be as short as possible in the axial direction (along the central axis of the aortic lumen) to minimize its space requirements in the ascending aorta, preferably having a short cylindrical, discoid, ellipsoid, donut or toroidal shape with an axial length of about 1-40 mm, preferably about 1-20 mm.Expandable member64 is attached to adistal end68 of ashaft70, which may be a rigid or flexible biocompatible metal or polymer.Shaft70 extends through the penetration in the aortic wall and out of the chest through anaccess port72 between theribs R. Shaft72 is at least about 6 cm, preferably about 10-20 cm, in length so that itsproximal end76 is outside of the chest whenexpandable member64 is in the ascendingaorta66 between thebrachiocephalic artery78 and the coronary ostia (not shown).
• [0086]Access port72, as with other access ports referred to in this application, is illustrated as a tubular cannula Or trocar sleeve, but may alternatively comprise a wound retractor with rigid blades or flexible adhesive strips for retracting tissue to create a small opening between the ribs. Instruments may alternatively be positioned directly through a puncture or incision between the ribs without a retractor, cannula or trocar, but usually some means of retracting tissue is desirable to prevent tissue damage and to facilitate introduction and manipulation of instruments. In some cases, it may be necessary to cut or remove one or more of the costal cartilages that connect the ribs to the sternum, to allow a slightly greater degree of rib retraction. However, in most cases, the access ports will be configured to facilitate introduction of surgical instruments, visualization devices, valve prostheses, and other devices used in the various procedures of the invention without removing the ribs R or sternum S, and preferably without retracting or cutting the ribs R significantly. Thus, the access ports will have a transverse profile suitable for positioning within an intercostal space I between two adjacent ribs R, which typically has a width (the distance between adjacent ribs R) of about 10-25 mm in normal adult patients, without cutting or removing the ribs, and without retracting the ribs more than about 1-2 cm from their natural, undeflected positions. In many cases, the access ports may be circular in cross-section with an outer diameter of less than about 12 mm so as to be easily positionable within an intercostal space I. In other cases the access ports may have a cross-sectional shape other than circular and may have a slightly larger transverse dimension to accommodate specialized instruments or prostheses, as described below.
• As shown in FIG. 4,[0087]shaft70 includes adelivery lumen80 extending from afirst connector82 atproximal end76 to adelivery port84 atdistal end68, through which cardioplegic fluid may be delivered into ascendingaorta66. Ifexpandable member64 is a balloon,shaft70 also has aninflation lumen86 extending from a second connector88 to the interior ofexpandable member64, through which an inflation fluid such as saline or contrast solution may be delivered into the balloon. In addition,shaft70 may optionally include anarterial return lumen90 extending from athird connector92 atproximal end76 to anarterial return port94 atdistal end68, through which oxygenated blood may be delivered into the aorta downstream ofexpandable member64.Third connector92 may be connected with tubing to the outlet ofcardiopulmonary bypass system20, allowingarterial return lumen90 to be used in place of or as a supplement to the use of separatearterial return cannula26 of FIG. 1.Shaft70 may also include a pressure lumen (not shown) extending fromproximal end76 to a pressure port (not shown) atdistal end68 to allow pressure monitoring in ascendingaorta66 upstream ofexpandable member64.
• [0088]Shaft70 is dimensioned so as to pass easily throughaccess port72 between ribs R, while having sufficient cross-section thatlumens80,86 and90 are large enough to perform their respective functions. Usuallyshaft70 will have an outer diameter of less than about 12 mm, preferably less than about 10 mm.Delivery lumen80 must be large enough in cross-section to allow cardioplegic fluid to be delivered at a sufficient flow rate to induce and maintain cardioplegic arrest, preferably allowing cooled cardioplegic fluid containing blood, usually having a viscosity of about 1-4 centipoise, to be delivered at a flow rate of at least about 200 ml/min at a pressure no more than about 300 mmHg. Thus,delivery lumen80 has a cross-sectional area of about 0.5-8 mm², preferably about 0.5-2.0 mm².Arterial return lumen90 is preferably large enough to allow blood to be delivered at flow rates adequate to maintain full cardiopulmonary bypass with the heart arrested (preferably without the use a separate arterial return cannula), having a cross-sectional area of about 12-75 mm², and preferably about 25-50 mm². In addition,inflation lumen86 must be large enough to allow saline or other inflation fluid to be delivered at flow rates sufficient to inflateexpandable member64 in less than about 30 seconds, preferably less than about 10 seconds, having a cross-sectional area of about 0.1-5 mm², preferably about 1-3 mm.
• A second embodiment of a thoracoscopic technique for inducing cardioplegic arrest is illustrated in FIGS.[0089]5-6. In this technique, anexternal clamp98 is placed around the ascendingaorta100 to occlude theaortic lumen102 just upstream of thebrachiocephalic artery104.Clamp98 is attached to adistal end106 of ashaft108 which is long enough to extend out of the chest through anaccess port110 between ribs R, having a length of at least about 10 cm, preferably 20-30 cm. Anactuator112 is attached toproximal end114 ofshaft108 to allowclamp98 to be opened and closed from outside of the chest.Actuator112 includes a pair ofmovable handles116 withfinger loops118, and alocking mechanism120 which may comprise a pair of overlappingfingers122 with transverse teeth (not shown) which interlock with one another.Clamp98 includes afirst jaw124 fixed toshaft108, and asecond jaw126 fixed to an inner shaft (not shown) extending through the interior ofshaft108 and rotatable relative toshaft108. One ofhandles116 is fixed to the proximal end ofshaft108, while a second ofhandles116 is fixed to a proximal end of the inner shaft, so that by pivotinghandles116 relative to one another, the inner shaft rotates relative toshaft108, opening or closingjaws124,126. Other aspects of thoracoscopic clamping devices suitable for use in the method of the invention are described in U.S. Pat. No. 5,425,705, which is incorporated herein by reference.
• In order to deliver cardioplegic fluid into the ascending aorta, several alternative techniques may be used. In one technique, illustrated in FIGS.[0090]5-6, adelivery cannula130 may be positioned through an inner lumen ofshaft108 so that aneedle132 at the distal end of the delivery cannula extends distally ofdistal end106 ofshaft108, generally parallel to and spaced apart fromjaws124.Jaws124 may be curved or angled away fromshaft108 so that the portions of the jaws that extend around the aorta are offset fromneedle132 to allowneedle132 to be placed throughshaft108 and penetrate the aortic wall upstream fromjaws124.Delivery cannula130 has an inner lumen extending from its distal end to its proximal end which may be connected to a cardioplegic fluid source. In one embodiment, aconnector134 is provided near the proximal end ofdelivery cannula130 which connects to a connector on the proximal end ofshaft108 to fix the delivery cannula in position relative to clamp98. In this way, afterclamp98 has been closed on ascendingaorta100 to occlude theaortic lumen102,delivery cannula130 may be positioned throughshaft108 to penetrate the aortic wall withneedle132, allowing cardioplegic fluid to be delivered upstream ofclamp98. The inner lumen ofdelivery cannula130 will be configured to facilitate delivering cardioplegic fluid containing blood at a rate of at least about 200 ml/min and a pressure of no more than about 300 mmHg, having a cross-sectional area of at least about 0.5 mm², and preferably 0.5-2.0 mm².Delivery cannula130 may alternatively be independent ofclamp98 andshaft108, and placed through a separate access port rather than being placed throughshaft108.
• Alternative techniques of delivering cardioplegic fluid are described in U.S. Pat. No. 5,425,705, which has been incorporated herein by reference. In one such technique, not illustrated here, an endovascular delivery catheter may be placed through a peripheral artery such as a femoral artery until its distal end is in the ascending[0091]aortic lumen102 upstream of thebrachiocephalic artery104.Clamp98 may then be actuated to close on the aorta around the endovascular delivery catheter, which may be reinforced in its distal extremity to prevent collapsing. In this way, cardioplegic fluid may be delivered upstream of theexternal clamp98 without requiring a puncture through the aortic wall. Such an endovascular delivery catheter may also include a pressure port and pressure lumen for monitoring pressure in the ascending aorta during the procedure.
• In a further embodiment of a thoracoscopic aortic occlusion technique, illustrated in FIGS.[0092]7-8, anexternal clamp136 is placed around the ascendingaorta138 by athoracoscopic clamp applier140, closed onaorta138 to block blood flow through the aortic lumen. then released fromclamp applier140, which may then be removed from the chest.Clamp136 comprises a pair ofmovable jaws142,144 pivotably connected to each other by apin152.Jaws142,144 haveproximal extremities154,156 proximal to pin152 to which alocking mechanism148 is mounted, which may comprise a pair of deflectable overlappingfingers150 havingtransverse teeth152 which interlock with one another to maintainclamp136 in a closed position. A pair ofdetents158 are disposed at the proximal ends ofjaws142,144 and are adapted to receive thedistal tips160 of clampapplier jaws162.Clamp136 is configured to be positionable through anaccess port146 or incision between ribsR. Access port146 has a transverse cross-sectional width to fit between the ribs without requiring significant deflection or removal of the ribs, but may have a longer transverse cross-sectional dimension parallel to the ribs to allowclamp136 to be positioned through the access port when held byclamp applier140.
• [0093]Clamp applier140 has, as shown in FIG. 7, anactuator164 at its proximal end which comprises one or moremovable leaves166 pivotably mounted to ashaft168.Leaves166 are linked to clampapplier jaws162 by alinkage170, best seen in FIG. 8, which may be a rod or wire slidably disposed in alumen171 withinshaft168, linked to ascissors mechanism172 coupled tojaws162. In this way, movingleaves166 towardshaft168 causesjaws162 to move between an open position for releasingclamp136 to a closed position for grasping andclosing clamp136.Clamp136 is preferably biased into an open configuration by a torsion spring (not shown) aroundpin152 or a compression spring (not shown) betweenproximal extremities154,156 ofjaws142,144. In this way, once lockingmechanism148 is released by deflectingfingers150 away from each other, clamp136 will be urged open as clampapplier jaws162 are opened. Other aspects and alternative configurations ofclamp136 and clampapplier140 are disclosed in commonly-assigned copending application Ser. No. 08/567,996, filed Dec. 4, 1995, now U.S. Pat. No. 5,618,307, which is hereby incorporated herein by reference.
• With[0094]clamp136 closed on the aorta to occlude blood flow through the aortic lumen, cardioplegic fluid may be delivered into the ascending aorta by means of adelivery cannula176 placed into the chest through anaccess port178 and having aneedle180 at its distal end for penetrating the aortic wall. Usually, a purse-string suture182 will be placed in the aorticwall surrounding needle180 using thoracoscopic needle drivers positioned through an intercostal access port. The purse-string suture182 is cinched up arounddelivery cannula176 to maintain hemostasis around the cannula. Alternatively, as discussed above, an endovascular delivery catheter (not illustrated) may be used which extends into the ascending aortic lumen transluminally from a peripheral artery such as the femoral, brachial, or subclavian artery.Clamp136 is clamped around the aorta after the endovascular delivery catheter has been positioned so that the inner wall of the aorta seals against the outer wall of the delivery catheter. The delivery catheter may be reinforced in its distal extremity to resist collapsing under the force ofclamp136. The delivery catheter may alternatively have an expandable member such as a balloon near its distal end which may be expended in the ascending aorta likeendoaortic catheter32 of FIGS.1-2.Clamp136 may then be applied to the ascending aorta directly around the expandable member to achieve complete occlusion without excessive crushing or collapsing of theaortal Clamp136 may also be placed distally or proximally of the expandable member, or a clamp may be placed in either side, to prevent migration of the expandable member as well as blocking blood flow.
• In addition, retrograde delivery of cardioplegic fluid via the coronary sinus by means of an endovascular catheter introduced through a peripheral vein (described above) may be used instead of or in combination with antegrade delivery through a thoracoscopic or endovascular delivery catheter placed in the aorta.[0095]
• It should be noted that, in some cases, it may be appropriate not to induce cardioplegic arrest, but instead to place the heart in a state of fibrillation. While this is usually not desirable because it is generally thought to provide inadequate protection of the myocardium, it may be induced using the devices and methods of the present invention. The patient is placed on cardiopulmonary bypass as described above (without occluding the ascending aorta so as to arrest the heart), and the oxygenated blood returned to the arterial system is cooled to a sufficiently low temperature to induce fibrillation. An endovascular or thoracoscopic catheter may be placed in the ascending aorta as described above, and, without occluding the ascending aorta, drugs or blood may be delivered to the coronary arteries, and fluids may be removed to vent the heart and aorta. Alternatively, one of the above-described aortic occlusion devices may be used to periodically induce fibrillation during the procedure by occluding the aorta temporarily without delivering the cardioplegic fluids that induce cardioplegic arrest, with intermittent periods of no occlusion so as to avoid ischemia.[0096]
• While the remainder of the aortic valve replacement procedure is described with reference to the use of[0097]clamp136 anddelivery cannula176 for inducing cardioplegic arrest, it should be understood that any of the devices and techniques described above, as well as various other techniques not specifically described here, may be used for inducing cardioplegic arrest without departing from the scope of the invention.
• Once cardioplegic arrest is induced, the patient is supported on cardiopulmonary bypass, and the pericardium has been opened as described above, an incision, or aortotomy,[0098]184 is formed in the wall of ascendingaorta186 as shown in FIGS.9-10. At this point. at least one, and usually at least three, access ports should be placed in intercostal spaces I between ribs R on the right anterior side of the chest. One or twoaccess ports188 with outer diameter less than about 12 mm are placed in the first, second, or third intercostal space through whichdelivery cannula176 and thoracoscope73 (if utilized) are positioned. Anotheraccess port190 with outer diameter less than about 12 mm is placed in the third, fourth or fifth intercostal space through which various instruments used in the procedure may be positioned. Anadditional access port192, which is specially-configured for positioning a replacement valve through its central lumen as described more fully below, is placed in the first, second, third or fourth intercostal space, depending upon patient size and anatomy. As described above,access ports188,190,192 may comprise trocar sleeves or other tubular cannulae, or simply incisions in which tissue is retracted apart to create a small opening using any of a variety of tissue retraction devices. Preferably, however,access ports188,190,192 will not require cutting or removal of ribs or the sternum, and will not require significant retraction of the ribs, preferably requiring less than about 2 cm of retraction from the ribs' natural, undeflected positions.
• It should be noted that, in the absence of a large thoracic incision for access into the chest, some means of illuminating the chest cavity is usually necessary. A thoracoscopic light wand or a commercially-available thoracoscope or endoscope having a fiber-optic channel which emits light from the distal end of the device may be placed through an access port for illumination. Alternatively, one or more access ports may have an illumination device mounted to it, as described below in connection with FIGS.[0099]37-40.
• [0100]Aortotomy184 is created using thoracoscopic angledscissors194 or a knife (not shown) positioned throughaccess port192, assisted by means ofthoracoscopic forceps196 positioned throughaccess port190.Angled scissors194 andforceps196 may be commercially-available thoracoscopic instruments or may be constructed as described in copending applications Ser. No. 08/194,946, now U.S. Pat. No. 5,501,698, and Ser. No. 08/281,962, now abandoned, which have been incorporated herein by reference.Aortotomy184 is approximately 6-8 cm in length, extending distally and slightly posteriorly along the anterior side of the aorta from a point at least about 10 mm, and preferably about 15 mm, downstream of the right coronary ostium.
• [0101]Aortotomy184 is then retracted open as illustrated in FIGS.11-12. In an exemplary embodiment, sutures200 are placed in the aortic wall along the edges ofaortotomy184, preferably with a suture near each end ofaortotomy184 on each side of the incision. Each ofsutures200 has aneedle202 attached to an end thereof which is driven throughaortic wall204 usingthoracoscopic needle drivers206 introduced through eitheraccess port190 oraccess port192.Needle drivers206 may be commercially-available thoracoscopic instruments or may be constructed as described in the aforementioned patent applications, Ser. Nos. 08/194,946, or 08/281,962, now abandoned.Sutures200 preferably have a length of at least about 20 cm so that they may be withdrawn from the chest cavity by passingneedles202 through the chest wall between ribs R or by snaring the sutures with a hook introduced through an intercostal space.Sutures200 are tensioned in opposing directions to retractaortotomy184 open and are then secured outside the chest withhemostats208 or other suitable clamping device of conventional construction. Alternatively, sutures200 may be secured to tissue within the chest cavity by passingneedles202 through such tissue and tying the sutures off, or by attaching the suture ends to a clip, clamp, hook or staple which can be fastened to tissue in the chest. Withaortotomy184 retracted open, theaortic valve210 is fully exposed and visible through theinner lumen212 ofaccess port192, as illustrated in FIG. 12.
• The[0102]leaflets214 of the nativeaortic valve210 are then removed using thoracoscopic curved orangled scissors194 or knife (not illustrated), andforceps196 positioned throughaccess ports190,192, respectively.Leaflets214 are grasped byforceps196, retracted away from thevalve annulus216, and cut closely to the inner edge ofvalve annulus216 without cutting into the valve annulus or the aortic wall.
• During this process, it may be advantageous to provide a mechanism for catching any bits of valve leaflet, calcium or other debris that may fall into the left ventricle as the leaflets are excised. As illustrated in FIG. 14, a[0103]catcher220 may be placed throughaortic valve210 into theleft ventricle222 and positioned so as to catch any debris released in the leaflet removal or debridement process.Catcher220 may comprise a flexible, porous mesh, foam, gauze, or screen constructed as a bag or pouch with anopening222 on atop end224 thereof.Top end224 is configured to be positioned in the left ventricle just below the aortic valve, with the sides ofcatcher220 engaging theventricular wall226. Preferablycatcher220 is collapsible into a smaller shape suitable for positioning throughaccess port190 oraccess port192, throughaortotomy184, and throughaortic valve210, and at leasttop end224 is resiliently biased to return to an expanded configuration in which the outer sides oftop end224 engageventricular wall226. A flexible and resilient metal orelastomeric ring228 may be mounted tocatcher220 around opening222 which may be radially collapsed during positioning, then released to allow the ring to expand outwardly to engage the ventricular wall. To facilitate positioning,catcher220 may be collapsed and placed in a tubular sleeve or catheter (not shown) during positioning through the aortic valve, then ejected from the sleeve within the left ventricle. Alternatively, thoracoscopic forceps or graspers positionable through an intercostal access port may be used to grasp and collapsecatcher220 and position it into the left ventricle. A suture or otherflexible tether230 is preferably attached tocatcher220 and extends out of the chest through an access port to allowcatcher220 to be retrieved after use. The aforementioned tubular sleeve may be guided overtether230 back into the left ventricle andcatcher220 then collapsed and retracted into the sleeve to facilitate removing the device from the chest.
• Following removal of the aortic valve leaflets, any calcific deposits and any remaining leaflet tissue around the inner surface of[0104]valve annulus216 are removed usingthoracoscopic rongeurs232.Rongeurs232 have a split-shaft construction, wherein twoindependent shaft members234,236 are longitudinally slidable relative to one another. A fixedjaw238 is disposed at the end ofshaft member234, and amovable jaw240 is pivotably mounted to the distal end ofshaft member236 by afirst pin242 and pivotably attached toshaft member234 by asecond pin244. In this way, longitudinal translation ofshaft member236 relative toshaft member234 by means of an actuator (not shown) at the proximal end of the device pivotsmovable jaw240 relative to fixedjaw238. Fixed jaw238 andmovable jaw240 have hollow or concave inner sides facing each other, and cuttingedges246,248 along the periphery of their inner sides. This construction allows cuttingedges246,248 to be positioned close to or against the inner surface ofvalve annulus216 to excise any remaining leaflet material or calcific deposits along the valve annulus. Any material removed is collected within the concave inner sides ofjaws238,240. In a preferred embodiment,rongeurs232 include a suction lumen through which a vacuum may be applied from the proximal end of the device to evacuate tissue and debris as it is cut fromvalve annulus216. In the split shaft design of FIG. 15, for example, at least one ofshaft members234,236 may be provided with an inner lumen in communication with the inner sides ofjaws238,240 through which a vacuum may be applied to evacuate material cut by cuttingedges246,248.
• In addition, an irrigation lumen may be provided in one of[0105]shaft members234,236 to allow an irrigation fluid such as saline to be delivered to the inner surfaces ofjaws238,240 to keep the jaws clean and free of debris. In one embodiment, a suction lumen is provided in oneshaft member234 and an irrigation lumen is provided in theother shaft member236 to provide both irrigation and suction in the space betweenjaws238,240.
• As an alternative to the use of[0106]thoracoscopic rongeurs232, various other devices may be used for removal of calcific and fibrous material at the native valve position, including high-speed rotating cutters or grinders like those used in atherectomy and arthroscopy devices, lasers, and ultrasonic scalpels, any of which may be equipped with irrigation or suction lumens.
• The valve annulus is then sized to determine the appropriate size for a replacement valve. As illustrated in FIG. 16, a[0107]valve sizing device250 is introduced throughaccess port192 into the ascendingaorta186 throughaortotomy184. Sizingdevice250 includes ashaft252 having a pivotingtongue254 at its distal end and ahandle256 at its proximal end. Asizing disk258 is releasably attached totongue254. Anactuator button260 is slidably mounted to handle256 and is connected totongue254 by a linkage (not shown) such as a slidable rod extending through a passage inshaft252. In this way, slidingactuator button260 alonghandle256pivots tongue254 from a first orientation in which the tongue is generally parallel toshaft252 to a second orientation in which the tongue is perpendicular toshaft252. Thus, for a generally cylindrical sizing disk having a central axis, sizingdisk258 is positionable in an orientation in which the central axis is perpendicular to the longitudinal axis ofshaft252, providing a minimum profile to allow the sizing disk to be introduced throughlumen212 ofaccess port192. Once inside the chest, sizingdisk258 may be re-oriented usingactuator button260 so that the sizing disk is in an appropriate orientation for sizingvalve annulus216, usually with its axis about parallel to the longitudinal axis ofshaft252 as shown in FIG. 16. Abutton lock262 may also be provided onactuator button260 to allowsizing disk258 to be releasably locked in a suitable orientation for sizingvalve annulus216. Other aspects of valve sizing devices suitable for use in the method of the invention are described in copending applications Ser. No. 08/485,600 and Ser. No. 08/281,962, which have been incorporated herein by reference.
• Once positioned inside ascending aorta.[0108]186 throughaortotomy184 and oriented in an orientation suitable for sizingvalve annulus216, sizingdisk258 is positioned withinvalve annulus216 to allow a comparison of the outer diameter of sizingdisk258 to the inner diameter ofvalve annulus216. To see the sizing procedure, the surgeon may look directly atvalve annulus216 throughlumen212 ofaccess port192 or a thoracoscope may be used for video imaging of the valve annulus. If the sizing disk is either larger or smaller than the valve annulus, sizingdevice250 is removed from the chest and sizingdisk258 is removed fromtongue254 and replaced with another sizing disk of a different diameter. The process is repeated until the surgeon has identified the appropriate size of replacement valve to be implanted. It should be understood that other techniques may be used for determining the annulus size, including endoscopic video imaging, transesophageal echocardiography, or thoracoscopic ultrasonic imaging, as well as using an adjustable valve sizer that may be placed within the valve annulus and adjusted in diameter until the appropriate size is determined.
• When the size of the valve annulus has been determined, the appropriate replacement valve is then identified. A variety of replacement valves may be used in the method of the invention, including many of the more widely-accepted valves used in conventional open-chest aortic valve replacement procedures. These include mechanical valves such as the St. Jude Medical Mechanical Heart Valve (St. Jude Medical, Inc., St. Paul, Minn.), the Carbomedics Prosthetic Heart Valve (Carbomedics, Inc., Austin, Tex.), and the Sorin Monostrut Heart Valve or Sorin Bicarbon Valve (Sorin Biomedical, Inc., Irvine, Calif.), as well as bioprosthetic or tissue valves, such as the Carpentier-Edwards Pericardial Bioprosthesis or Carpentier-Edwards Model 2625 Porcine Bioprosthesis (Baxter, Inc., Edwards CVS Division, Irvine, Calif.), or Medtronic Hancock Mo. Bioprosthesis or Medtronic Hall valve (Medtronic, Anaheim, Calif.). In addition, the method of the invention may be used to replace a diseased aortic valve with an autologous graft such as the pulmonary valve from the same patient, which may be removed thoracoscopically from the patient's pulmonary artery using thoracoscopic instruments and visualization devices positioned through access ports between the ribs. Allografts, such as an aortic valve removed from another donor patient's heart, may also be implanted using the methods of the invention. While the aortic valve replacement procedure of the invention will be described with reference to a mechanical bileaflet valve such as the St. Jude Medical Mechanical Valve, it should be understood that the methods described are equally applicable to other types of mechanical valves, as well as to bioprosthetic valves, autografts and allografts.[0109]
• In order to implant most mechanical valve prostheses, a plurality of[0110]sutures264 are placed in the native valve annulus to form mattress stitches or inverted mattress stitches. As shown in FIGS.17-18,sutures264 are double-armed witharcuate needles266 on both ends, and are placed invalve annulus216 using a specializedrotational needle driver268, described in detail in copending application Ser. No. 08/594,869, entitled “Endoscopic Suturing Devices and Methods”, which is hereby incorporated herein by reference.Rotational needle driver268 has ashaft270 with arotatable carriage272 at its distal end ahandle274 at its proximal end. One ofneedles266 is releasably held incarriage272 such that the needle'ssharp point274 is exposed outside of the carriage.Carriage272 is rotatable about apin276 inshaft270. Anactuator button278 is slidably mounted to handle274 and is coupled tocarriage272 by a linkage (not shown) such as a slidable rod within a passage inshaft270. In this way, sliding actuator button alonghandle274 rotatescarriage272 aboutpin276.Carriage272 may be configured to drivesharp point275 ofneedle266 in either a distal or proximal direction, depending upon whether it is desired to drive the needle from the ventricle toward the aorta, or from the aorta toward the ventricle. In the embodiment illustrated,rotational needle driver268 is set up to driveneedle266 from theleft ventricle222 towardaorta186.Carriage272 holdingneedle266 is positioned throughaccess port192, throughaortotomy184 and throughvalve annulus216.Sharp point275 ofneedle266 is then positioned so as to penetrate the valve annulus a distance of about 1-5 mm from the inner edge of the annulus, as visualized by looking throughaccess port192 or under thoracoscopic visualization. When the needle is properly positioned,actuator button278 is moved alonghandle274 to translateneedle266 throughvalve annulus216. Oncesharp point275 emerges from the annulus within the aorta, the needle may be picked up withthoracoscopic needle drivers206 positioned through access port192 (or through a separate access port). In an alternative embodiment, a needle pick-up mechanism (not shown) is provided onneedle driver268 to allowneedle266 to be picked up without the use of a separate instrument, as described in the above-mentioned patent application Ser. No. 08/594,869, entitled “Endoscopic Suturing Devices and Methods”. Whenneedle266 is picked up, it is drawn throughvalve annulus216 and withdrawn from the chest throughlumen212 ofaccess port192. A total of 10-20 sutures are placed invalve annulus216 in this way.
• Because of the large number of sutures that are placed in[0111]valve annulus216, a suture organizing device is provided outside the chest to keep the sutures orderly and free of tangles. In a preferred embodiment, a suture organizer279 is disposed on the proximal end ofaccess port192 itself, the suture organizer including a plurality ofradial slits280, usually 12-24 pairs, arranged around the circumference of arim282 onaccess port192.Slits280 are configured to frictionally engagesutures264 placed into the slits, allowing eachsuture264 to be placed invalve annulus216, drawn out of the chest and placed in one ofslits280 until all of the sutures have been placed Other aspects of suture organizer279 are described in copending application Ser. No. 08/485,600, which has been incorporated herein by reference.
• In the case of certain bioprosthetic valves and other types of replacement valves, techniques may be used for securing the valve to the heart which do not require a plurality of sutures to be placed in[0112]valve annulus216. For example, some tissue valves are secured using a single continuous length of suture to make a running stitch around the sewing ring of the replacement valve. In other cases, staples, clips or other fastening devices may be used to secure the replacement valve to the native annulus or adjacent tissue. In such cases, it may be unnecessary to place sutures or other fasteners invalve annulus216 until after the replacement valve has been introduced into the chest and positioned at the aortic valve position.
• With all of[0113]sutures264 placed invalve annulus216 and the ends ofsutures264 organized outside of the chest, each suture is placed throughsewing ring286 ofprosthetic valve288, which is held by adelivery handle290. Delivery handle290 has an elongatedshaft291 and ahandle293 at its proximal end, and may be the same handle used invalve sizing device250 described above in reference to FIG. 16, with sizingdisk258 removed fromtongue254.Prosthetic valve288 is releasably held on aholder292 which includes a slot or aperture (not shown) configured to receive a tongue ondelivery handle290 similar totongue254 onvalve sizing device250. Various other details concerning the construction ofdelivery handle290,prosthetic valve288, andholder292 are described in copending application Ser. No. 08/281,962 and application Ser. No. 08/485,600, which have been incorporated herein by reference. A needle driver of conventional construction is used to grasp each ofneedles266 and drive it throughsewing ring286. After each needle is driven through the sewing ring, it is secured by means of ahemostat294 or by placement in a suture organizer positioned on or near the patient's chest.
• [0114]Delivery handle290 is configured to allowprosthetic valve288, mounted toholder292, to be delivered through an intercostal access port with minimal retraction of the ribs. If theannular sewing ring286 has a central axis extending through it (generally defining the direction of blood flow through the valve), delivery handle290 preferably holdsprosthetic valve288 in an orientation in which the central axis ofsewing ring286 is generally perpendicular to the longitudinal axis ofshaft291, wherein the prosthetic valve, holder, and delivery handle have a minimum profile in a direction perpendicular to the longitudinal axis ofshaft291. This will allowprosthetic valve288 to be delivered through an intercostal space without removing or cutting the ribs or the sternum, and, in most patients, without retracting the ribs. Certain types of prosthetic valves, particularly tissue valves, may have a larger profile. due to the height of the valve commissures. However, even for these prosthetic valves, delivery handle290 is adapted to hold the prosthetic valve in an orientation of minimum profile, allowing the prosthetic valve to be positioned into the chest with minimal retraction of the ribs, usually with less than about 10 mm of retraction of each rib from its natural, undetected position, and preferably less than about 5 mm from the rib's natural, undeflected position.
• To facilitate positioning[0115]prosthetic valve288 through an intercostal space without interference with the ribs or tissue of the chest wall, the prosthetic valve is placed throughinner lumen212 ofaccess port192, as illustrated in FIG. 20.Inner lumen212 is specially adapted to allowprosthetic valve288 to pass through it in an edge-first orientation. Preferably, the prosthetic valve is positioned throughlumen212 such that the central axis ofsewing ring286 is generally perpendicular to the longitudinal axis ofinner lumen212. At the same time, the overall profile ofaccess port192 is minimized so as to require an incision in the chest wall of minimum size. In a preferred embodiment, the cross-section ofinner lumen212 in a direction perpendicular to its longitudinal axis has a cross-sectional length which is substantially greater than its cross-sectional width, with an oval, rectangular, racetrack, elliptical, or other shape suitable for passage ofprosthetic valve288 in the edge-first orientation illustrated. The cross-sectional length will be just larger than the outer diameter ofsewing ring286, usually 17-35 mm, and the cross-sectional width will be just larger than the height of the valve parallel to the central axis ofsewing ring286, ranging from about 5-25 mm for mechanical valves, to about 15-30 mm for tissue valves.
• Of course, a variety of other devices may be used to retract the chest wall tissue to allow[0116]prosthetic valve288 to be introduced into the chest, including a soft tissue retractor designed to atraumatically retract tissue adjacent to an intercostal incision to create an opening in the chest without retracting the ribs. Alternatively, a conventional retractor with a pair of movable parallel rigid blades may be positioned in an intercostal incision parallel to the ribs, the distance between the blades being adjustable to create an opening in the intercostal space of a desired width. Such an adjustable retractor may be desirable where the height and outer diameter of the prosthetic valve are both larger than the distance between the ribs in the intercostal space through which the prosthetic valve is to be positioned, as may be the case with certain types of tissue valves. In this way, the ribs may be slightly retracted temporarily to allow the prosthetic valve to be positioned into the chest, and the retractor then re-adjusted to allow the ribs to return to their natural, undeflected positions for the remainder of the procedure, thus minimizing the trauma associated with such retraction.
• As[0117]prosthetic valve288 is advanced into the chest, tension is maintained onsutures264 by means ofhemostats294 or an assistant's hands so thatsewing ring286 slides alongsutures264 towardaortic valve annulus216. Delivery handle290 has a length sufficient to allowprosthetic valve288 to be positioned at the native aortic valve position in the heart withhandle293 remaining outside the chest,shaft291 preferably having a length of at least about 15 cm. Once inside the chest,prosthetic valve288 may be reoriented into an orientation suitable for securing the valve tovalve annulus216, i.e., an orientation in whichsewing ring286 may be positioned parallel to and axially-aligned with valve annulus216 (illustrated in FIG. 21). Such reorientation may be accomplished by simply removingprosthetic valve288 fromdelivery handle290, but is preferably accomplished by pivotingprosthetic valve288 relative toshaft291 by sliding anactuator button296 onhandle293. This pivots a tongue at the distal end ofshaft291 to whichholder292 andprosthetic valve288 are attached, in a manner like that described above with reference tovalve sizing device250 of FIG. 16 (and described in copending application Ser. No. 08/485,600, which has been incorporated herein by reference). Usually,prosthetic valve288 is reoriented such that the central axis ofsewing ring286 is generally parallel to the longitudinal axis ofshaft291 plus or minus about 30°, although the exact angular orientation may vary according to the location ofaccess port192 and patient anatomy.
• [0118]Prosthetic valve288 is positioned adjacent to thevalve annulus216 and then released fromdelivery handle290, which may then be removed from the chest, as illustrated in FIG. 21.Prosthetic valve288 is preferably released by cutting a suture (not shown) on bolder292 as frequently provided on conventional prosthetic valve holders. This allows a movable portion ofholder292 to pivot away fromsewing ring286, releasing the prosthetic valve from the holder, as described in greater detail in copending application Ser. No. 08/281,962, which has been incorporated herein by reference.
• Referring now to FIG. 22,[0119]knots300 are formed in each ofsutures264 outside of the chest, and athoracoscopic knot pusher302 is used to pushknots300 alongsutures264 throughlumen212 ofaccess port192, throughaortotomy184 and againstsewing ring286 ofprosthetic valve288.Knot pusher302 preferably has an elongatedshaft303 to which is attached ahead304 with a convex curvature on itsdistal end306 and a pair ofaxial channels308,310 along its lateral sides, as described in copending application Ser. No. 08/288,674, filed Aug. 10, 1994, which is hereby incorporated herein by reference. One end of each suture is threaded throughchannel308, aknot300 is formed in the suture distally ofhead304, and the other end of the suture is positioned in channel310. While holding the ends ofsuture264 in tension,knot pusher302 is advanced towardprosthetic valve288, engagingknot300 withdistal end306 and sliding the knot alongsuture264 until it is againstsewing ring286. Several knots are formed in each suture in this manner. The ends ofsutures264, along withneedles266, are then trimmed off aboveknots300, using thoracoscopic angledscissors194 or other suitable cutting device.
• With[0120]prosthetic valve288 successfully secured in the aortic valve position, themovable leaflets312 may be tested for proper action by inserting a probe (not shown) through an access port and exerting a gentle force against the outer edges of the leaflets. The probe may comprise an elongated shaft with an atraumatic tip of a soft elastomer suitable for contacting the valve leaflets, like that described in copending application Ser. No. 08/485,600, which has been incorporated herein by reference. Alternatively, the probe may include an inner lumen extending to a port at its distal end, the inner lumen being adapted for connection to a source of suction outside the chest, whereby suction may be applied to the valve leaflets to test for proper opening and closing.
• If[0121]leaflets312 are functioning properly,aortotomy184 may be closed. This may be accomplished, as illustrated in FIG. 23, by suturing the opposing edges of the aortic incision together using a conventional running stitch applied by means ofthoracoscopic needle drivers206 positioned throughaccess ports188,190 or192. Alternatively, an endoscopic stapler may be used to apply a series of staples acrossaortotomy184.
• While[0122]aortotomy184 is being closed, it will usually be desirable to remove any air from within the left ventricle and ascendingaorta186 upstream ofaortic clamp136. This is accomplished by first reducing venous drainage of the heart viavenous cannula22 to allow blood to flow from the right side of the heart into the left ventricle, thereby filling the left ventricle with blood. This forces air out of the left ventricle into the ascending aorta. Preferably, the patient will be positioned so that the superior or anterior aspect of the aortic arch is upward so that any air collects at a point where it can be suctioned out throughdelivery cannula176. An irrigation fluid such as saline may also be delivered throughdelivery cannula176 into the ascending aorta and left ventricle to assist in displacing air to the upper part of the ascending aorta neardelivery cannula176. Additionally, thoracoscopic instruments may be positioned through intercostal access ports to depress and collapse the heart, forcing out any air in the left ventricle. Heart manipulation devices may also be positioned through an access port to lift and/or rotate the heart so that any air tends to flow through the aortic valve into the ascending aorta, where it may be suctioned out. Further, small needles may be used to aspirate air from the left ventricle and/or aorta.
• In an alternative technique of keeping air out of the heart during the procedure, the chest cavity may be flooded with a gas such as carbon dioxide at the outset[0123]6fthe procedure to prevent any air from entering the chest through the access ports. A gas delivery tube may be introduced through an intercostal access port, or a gas delivery lumen may be provided in a wall of the one of the access ports themselves through which the gas is delivered. To facilitate maintaining the gas within the chest, the access ports may be provided with gaseous seals such as those commonly used in laparoscopic trocar sleeves which provide a gas-tight seal both when an instrument is introduced through the port, as well as when the instrument is removed. These and other techniques for removing air from the heart and aorta are disclosed in copending application Ser. No. 08/585,871, filed Jan. 12, 1996, entitled “Methods and Apparatus for Preventing Air Embolism When Performing A Procedure On A Patient's Cardiovascular System,” which is incorporated herein by reference.
• With de-airing complete, cardiac function may be allowed to resume. The patient's head is temporarily tilted head-down to prevent emboli from entering the cerebral circulation. Aortic clamp[0124]136 (or other aortic occlusion device) is removed from ascendingaorta186 to allow oxygenated blood delivered viaarterial return cannula26 to flow into the ascending aorta and into the coronary arteries. To removeclamp136, clamp applier140 (FIGS.7-8) is reintroduced into the chest viaaccess port192, andproximal extremities154,156 are engaged by clampapplier jaws162 and actuated so as to releaselocking mechanism148, allowingjaws142,144 to return to an open position.Clamp136 is then withdrawn from the chest cavity. Oxygenated blood is then permitted to flow through the coronary arteries to perfuse the myocardium, whereupon cardiac contractions will quickly resume. In the event that cardiac function does not return spontaneously, electrical defibrillation may be utilized to restore normal heart beat. Defibrillation electrodes may be placed on the heart via intercostal access ports, or external paddles of conventional construction may be used on the surface of the chest, and an electrical charge may then be delivered to stimulate the heart.
• When cardiac contractions have resumed, it may still be desirable to maintain suction through[0125]delivery cannula176 so as to remove any air or other emboli which may be present in the aorta or left ventricle. When it is believed that such emboli are no longer present,delivery cannula176 is removed from ascendingaorta186 and purse-string suture182 (FIG. 8) is tightened securely and knotted to close the puncture in the aortaThoracoscopic needle drivers206 may be used for this purpose. Thoracoscopic scissors are then used to trim the ends of purse-string suture182.
• The patient is then weaned from cardiopulmonary bypass in the conventional manner, and[0126]venous cannula22,arterial return cannula24,coronary sinus catheter52, any other catheters utilized in the procedure, andaccess port188,190,192, are removed from the patient. Chest drainage tubes may be placed temporarily through incisions used for access, or through additional incisions. All other thoracic and vascular punctures and incisions are closed, and the patient is recovered from anesthesia.
• While the invention has been described in the context of aortic valve replacement, various other procedures may be performed using the methods of the invention, including repair or replacement of the mitral, pulmonary or tricuspid valves; repair of atrial and ventricular septal defects and patent ductus arteriosus by means of stapling, suturing or patch-applying instrument positioned into the heart; transmyocardial revascularization by means of a laser introduced into the heart; electrophysiological mapping and ablation by means of a mapping and ablation catheter positioned into the heart; performance of a Cox maze procedure by means of a cutting or ablation device positioned in the heart for transecting the atrial wall to correct atrial fibrillation; and pulmonary embolectomy by positioning a embolus-removal device into the pulmonary artery. Advantageously, in each such procedure, all instruments may be introduced into the heart either through intercostal access ports or via blood vessels with the surgeon's hands outside the chest, eliminating the need for a median sternotomy or other form of gross thoracotomy.[0127]
• Another exemplary embodiment of a delivery handle for positioning either a sizing disk or a replacement valve through an intercostal access port and into the native valve position is illustrated in FIGS.[0128]24-26. In this embodiment, delivery handle320 comprises ashaft322 having adistal end324 and aproximal end326. A sizing disk or a holder for releasably holding a replacement valve, represented schematically bycylindrical element328, is pivotably mounted todistal end324 by atransverse pin330. (A pair of finger grips332 are fixed toshaft322 nearproximal end326, and anend cap334 is slidably received overproximal end326.
• As shown in FIG. 26, a[0129]rod336 extends through aninner lumen338 inshaft322.Rod336 has aproximal end340 fixed to endcap334, and adistal end342 rotatably pinned toelement328 at a point laterally offset fromtransverse pin330. Aspring344 is disposed within abore346 withinend cap334 and engages the proximal end ofshaft322 to biasend cap334 androd336 in the proximal direction. In this way,element328 may be pivoted relative toshaft322 by pushingend cap334 distally with the thumb while the fingers are placed against finger grips332.Element328 is usually rotatable through an angle of at least about 45°, and preferably at least about 90°, relative toshaft322. In a preferred embodiment, delivery handle320 is configured to positionelement328 in an orientation suitable for introduction through an intercostal access port without removing, cutting, or significantly retracting the ribs. As illustrated in FIG. 25,element328 is preferably movable into an orientation in which the central axis AA extending axially throughcylindrical element328 is generally perpendicular +/−20° relative to the longitudinal axis LA ofshaft322. In this way, the profile of delivery handle320 together withelement328 as seen from the distal end of the device is minimized.Element328—whether a sizing disk or replacement valve—may be introduced through an intercostal access port (such asaccess port192 of FIGS.7-24) in the orientation of FIG. 25 by maintaining pressure againstend cap334. Once inside the chest,end cap334 may be released, allowingelement328 to return to the orientation of FIG. 24, wherein the element is in a suitable orientation for alignment with the native valve annulus for either sizing the annulus or implanting the replacement valve. Usually,element328 will be oriented such that central axis AA is at an angle of between −45° and 45°, and preferably about 0°+/−20°, relative to the longitudinal axis LA ofshaft322.
• FIGS.[0130]27-29 illustrate an additional embodiment of an access port for retraction of tissue within an intercostal space so as to provide an open passageway through which a replacement valve may be positioned into the chest.Access port350 comprises atubular body352 having anaxial passage354 configured to allow a replacement valve to be positioned through it without contacting the inner walls of the axial passage.Tubular body352 is a metal or biocompatible polymer with sufficient rigidity to retract intercostal tissue and to retain a shape suitable for positioning a replacement valve through the axial passage into the chest.Axial passage354 preferably has a cross-sectional shape suitable for introducing a replacement valve or sizing disk through it in the edge-first orientation illustrated in FIG. 25, such as oval, elliptical, racetrack, rectangular, trapezoidal, or other suitable shape.Axial passage354 will have a cross-sectional width orthogonal to a central axis AX of less than about 30 mm, usually about 10 mm-25 mm, and preferably about 15 mm-20 mm. The cross-sectional length ofaxial passage354 orthogonal to central axis AX will be larger than the outer diameter of the replacement valve utilized, and usually substantially larger than the cross-sectional width of the axial passage, usually being about 15 mm-50 mm, and preferably being about 25 mm-40 mm.Tubular body352 has an exterior shape and dimensions suitable forpositioning access port350 in an intercostal space without cutting or removing the ribs, and preferably without significant retraction of the ribs from their natural, undeflected positions (e.g. less than about 10 mm of retraction). In an exemplary configuration, the outer surface oftubular body352 has a shape corresponding to that ofaxial passage354 with a wall thickness therebetween of about 0.25-2 mm, preferably 0.75-1.25 mm. Of course, the exact size and shape oftubular body352 will be determined by the size and shape of the replacement valve to be utilized in the procedure.
• [0131]Access port350 may further include aflange356 on its proximal end which engages the outer surface of the patient's chest. A suture organizer358 is preferably mounted toflange356, and includes anannular wall360 with a plurality ofradial slits362 in spaced-apart locations around its circumference. Eachslit362 is configured to receive a suture thread and frictionally retain it as described above in connection with FIGS.18-19.
• [0132]Access port350 additionally includes aretention mechanism364 mounted to a distal extremity oftubular body352 for retaining the access port in the chest wall. As illustrated in FIG. 28,retention mechanism364 comprises asleeve366 slidably mounted ontubular body352 and coupled toflange356 by a pair of tension springs368, which may be elastomeric bands or cords. Aretention element370 is mounted near the distal end ofsleeve366 and is collapsible for introduction through an intercostal space in the chest wall, and then expandable into a configuration in which the retention element engages the inner wall of the chest. In the exemplary configuration illustrated in the figures,retention element370 comprises a continuousflexible band372 which extends through two pairs ofslots374 on opposing sidewalls ofsleeve366 forming twoinner loops376 in the interior ofsleeve366 and twoouter loops378 exterior tosleeve366.Band372 is preferably a resilient, flexible metal, plastic or elastomer which is biased into a fully expanded oval or circular ring shape. By compressingouter loops378 radially inward towardsleeve366, a portion ofband372 slides throughslots374, enlarginginner loops376 and collapsingouter loops378 into the configuration illustrated in FIG. 28. To, expandouter loops378, inner loops are pushed outwardly againstsleeve366.
• An assembly view of[0133]access port350 is illustrated in FIG. 29.Annular wall360 has a plurality ofopenings380 formed around its circumference. Aninsert assembly382 has asupport ring383 with a plurality ofelastomeric inserts384 attached thereto and configured to fit intoopenings380. A lower end of eachinsert384 is configured to be received in one of a plurality of slots (not shown) inflange356 aligned with eachopening380. Eachinsert384 has an enlargedlower end386 which engages the lower surface offlange356 to retain the insert withinopening380. In this way, the adjacent surfaces ofinserts384 andwall360 withinopenings380 form radial slits362 (FIG. 27).Inserts384 will preferably have sufficient compliance to deflect slightly as a suture thread is drawn intoslit362, and sufficient resilience to maintain pressure against the thread to retain it in the slit.
• Also attached to support[0134]ring383 are tension springs368, which may comprise resilient elastomeric bands or cords, extending distally through a pair of appropriately aligned slots (not shown) inflange383.Sleeve366 has a pair ofears388 at its proximal end with axial passages through which tension springs368 may extend. Eachtension spring368 has a flange orledge390 at its distal end which retains the tension spring inear388.
• To facilitate expanding and collapsing[0135]retention element370, the invention provides a specialized obturator for use withaccess port350, illustrated in FIGS.30-31.Obturator392 has ashaft394 shaped to occludeaxial passage354 ofaccess port350. Adistal end396 ofshaft394 is tapered to facilitate introduction through a puncture or incision in the chest wall. Ahandle398 is fixed to the proximal end ofshaft394. A pair ofhooks400 are movably coupled toshaft394 neardistal end396 and form a distally-openU-shaped channel401 configured to receiveinner loops376 ofband372. As illustrated in FIGS.31A-31B, hooks400 are mounted to a pair ofactuators402 pivotably mounted to handle398 by apin404 such thatactuators402 move in a scissors-like manner.Actuators402 each have an outwardly extendingbutton406 which extends through anaperture408 inhandle398.Actuators402 are biased outwardly by a torsion orU-shaped spring410. In this way, pressingbuttons406 inwardly moveshooks400 from the outward position illustrated in FIG. 31A to the inward position illustrated in FIG. 31B.
• [0136]Obturator392 further includes alocking mechanism412 comprising apivotable locking button414 mounted within anopening416 inhandle398. Lockingbutton414 has afoot418 extending from a distal surface thereof. Each ofactuators402 has anotch420 on a proximal surface thereof which is configured to receivefoot418. Atorsion spring422biases locking button414 in a clockwise direction. When actuators402 are pivoted inwardly,foot418 slides along the proximal surfaces ofactuators402 untilnotches420 are aligned. This allowsfoot418 to slide intonotches420, lockingactuators402 in the inward position, as shown in FIG. 31B. The locking mechanism is released by pushing on the proximal surface oflocking button414 on the side opposite that offoot418, pivotinglocking button414 counterclockwise to removefoot418 fromnotches420.
• In use,[0137]obturator392 is positioned inaxial passage354 ofaccess port350 such that hooks400 extend aroundinner loops376 ofband372 to position the band inchannels401.Buttons406 are then pressed inwardly, drawinginner loops376 inwardly and collapsingouter loops378 against the outer surface ofsleeve366.Access port350 may then be positioned through an incision or puncture through the chest wall between two ribs. Whenband372 is inside the chest cavity, lockingbutton414 is released, allowingactuators402 and hooks400 to return to the outward position.Outer loops378 are thereby deployed into their expanded configuration, andobturator392 may be removed fromaxial passage354. Tension springs368pull sleeve366 towardflange356 ontubular body352, compressing the chest wall betweenband372 andflange356.Access port350 is thus firmly held in position during the procedure. To remove the access port from the chest,obturator392 is reinserted intoaxial passage354 such that hooks400 engageinner loops376,buttons406 are pressed inwardly to collapseouter loops378, andaccess port350 is withdrawn from the intercostal incision.
• Referring now to FIGS.[0138]32-33, a preferred embodiment of a holder for an aortic valve prosthesis according to the invention will be described. As shown in FIG. 32,holder430 is attached to the distal end of delivery handle320 in place ofelement328, described above in connection with FIGS.24-26.Holder430 is pivotable relative toshaft322 from a first orientation of minimum profile suitable for introduction through an intercostal space, to a second orientation suitable for aligning the prosthetic valve with the native valve annulus so that it may be secured thereto. Preferably, as described above, in the first orientation,holder430 is positioned such that the central axis of the prosthetic valve sewing ring is generally perpendicular to the longitudinal axis ofshaft322, as shown in phantom in FIG. 32. In the second orientation,holder430 is preferably positioned so that the central axis of the prosthetic valve sewing ring is generally parallel to the longitudinal axis ofshaft322.
• A configuration of[0139]holder430 will be described which is appropriate for use with a mechanical bileaflet aortic valve prosthesis such as the St. Jude Medical Mechanical Aortic Valve. However, it will be understood to those of ordinary skill in the art thatholder430 may be configured to accommodate a wide variety of prosthetic valves without departing from the scope of the invention. As shown in FIGS.33A-33B,holder430 is configured to holdprosthetic valve432 from its downstream side withmovable valve leaflets434 in their closed position. In this position,valve leaflets434 form a V-shaped space within the interior of the valve surrounded byannular valve body436 andsewing ring438.Holder430 therefore has a peaked or wedge-shapeddistal surface440 with angled faces441A,441B forming an angle a of between about 90° and 150°, which fits within the V-shaped spaceadjacent valve leaflets434. An annular rim orflange442 is configured to abutannular sewing ring438 ofprosthetic valve432. Ahandle coupling444 is attached to theproximal surface446 ofholder430 and is configured to be attached todelivery handle320. Handle coupling444 has atransverse channel448 as shown in FIG. 33B configured to receive the distal end ofshaft322. A pair ofholes450,452 extend throughhandle coupling444 acrosschannel448 and may be aligned withholes454,456 in delivery handle320 so that pins may be inserted therethrough. In this way, by slidingrod336,holder430 pivots relative toshaft320.
• [0140]Prosthetic valve432 may be removably attached toholder430 in various ways. In a preferred embodiment, sutures are placed throughsewing ring438 and through bolder430 and tied in order to secure the prosthetic valve to the holder. For this purpose,holder430 may include holes, loops, eyelets or the like proximal torim442 through which sutures may be placed. Alternatively,holder430 may be made of a soft elastomeric material through which a suture needle may be driven to secure the suture to the holder. When it is desired to remove the prosthetic valve fromholder430, the sutures are cut with scissors or a knife.
• Certain prosthetic valves are designed to allow the valve body and valve leaflets to be rotated relative to the sewing ring of the prosthesis after the sewing ring has been secured to the heart. Advantageously, once[0141]holder430 has been removed fromprosthetic valve432 and the prosthetic valve secured in the heart,holder430 may be used to rotatevalve body436 along withleaflets434 byrepositioning holder430 within the V-shaped space formed byleaflets434 androtating handle320 about its longitudinal axis. A flat458 is provided along the two sides ofholder430 which are positioned adjacent to side supports459 ofprosthetic valve432, allowing torque to be transmitted tovalve body436 rather than to thefragile valve leaflets434.
• FIGS.[0142]34-36 illustrate an alternative embodiment of a holder according to the invention. In this embodiment ,holder460 is configured to hold a bi-leaflet mechanical valve from its upstream side for replacement of a diseased cardiac valve from the upstream side of the native valve, e.g., for replacement of the mitral valve via an incision in the left atrium as described in copending application Ser. No. 08/281,962 and Ser. No. 08/485,600, which have been incorporated herein by reference. As shown in FIG. 34,mechanical bileaflet valve462 has a pair ofleaflets464 movably attached to a pair of upwardly extending side supports465 on anannular valve body466. Asewing ring468 is attached tovalve body466.Leaflets464 are pivotable between an open position wherein the leaflets are nearly parallel, to a closed position wherein the inner edges ofleaflets464 abut one another and the curved outer edges of the leaflets abut the inner surface ofannular valve body466. As shown in FIGS.35-36,holder460 is configured to be positioned on the upstream side ofvalve462 withleaflets464 in the open position.Holder460 has adistal end470 having a pair of crescent-shapedfeet472 for positioning between the outer (upstream) surface of eachleaflet464 and the inner surface ofvalve body466. Anarcuate channel474 extends acrossdistal end470 betweenfeet472 which accommodates side supports465 and the inner ends ofleaflets464. Arim476 extends around the perimeter ofdistal end470 which abutssewing ring468 and/orvalve body466.Holder460 is adapted for attachment to delivery handle320 by ahandle coupling480 extending laterally from a proximal end of the holder. Handle coupling480 has a pair ofholes482,484 which may be attached to delivery handle320 as described above in connection with FIGS.33A-33B.
• [0143]Prosthetic valve462 may be releasably attached toholder460 in various ways. In a preferred technique,holder460 is constructed of a soft elastomer which allows a suture needle to be driven through it. In this way, one or more sutures may be placed throughsewing ring468 and throughholder460 and tied to secure the valve to the holder. Alternatively,holder460 may be a more rigid material and holes, eyelets, or loops may be mounted to the holder to which sutures may be secured. Whenvalve462 is to be released, the sutures are simply cut.
• An additional embodiment of an access port according to the invention is illustrated in FIGS. 3740. In this embodiment,[0144]access port490 comprises atubular cannula492 having adistal end494, aproximal end496, and alumen498 through which any of the replacement valves, valve holders and valve delivery devices described above may be positioned without interference. As described above in connection with FIGS.27-29,lumen498 is preferably oval-shaped, but the lumen may be any of a variety of shapes suitable for introducing a prosthetic valve into the chest with minimal retraction of the ribs.Cannula492 has awall500 constructed of a material having sufficient rigidity to retract intercostal tissue so as to provide an opening into the chest through which a replacement valve may be positioned. Arim501 is provided atproximal end496 which is adapted to engage the outer surface of the chest. An obturator (not shown) removably positionable withinlumen498 may also be provided to facilitate introduction through the chest wall.
• As best seen in FIGS.[0145]38-39, achannel502 extends axially throughwall500 betweenproximal end496 anddistal end494. A plurality of axially-extendingoptical fibers504 are distributed aroundchannel502 so as to surroundlumen498 and are potted, bonded or other wise fixed withinchannel502 such that distal ends506 of the optical fibers are disposed neardistal end494 of the cannula and are pointing generally in the distal direction.Optical fibers504 extend proximally throughchannel502, through anannular space508 withinrim501, and into aflexible cable510 attached torim501 that has a protective,opaque jacket511 surrounding the optical fibers. Anoptical coupling512 is fixed to the free end ofcable510 and is configured to be coupled to a conventional fiber optic light source of the type used for fiber optic lighting in endoscopes and the like, allowing light to be transmitted from the light source throughoptical fibers504 and emitted from their distal ends506.
• In use,[0146]cannula492 is positioned within a small incision between two ribs such thatdistal end494 is within the chest cavity. Coupling512 is connected to a light source so that light is emitted fromoptical fibers504 so as to illuminate the chest cavity. Various surgical procedures may then be performed within the chest using instruments positioned throughlumen498 or through other access ports under the illumination provided byoptical fibers504. For example, the various steps of an aortic valve replacement procedure as described above may be performed under illumination provided byaccess port490. Advantageously,access port490 may be positioned in alignment with the aortic valve to provide the optimum angle of illumination, while at the same time providing the optimum angle of approach to the valve for introduction of instruments, valve sizers, and the prosthetic valve itself throughlumen498. The provision ofoptical fibers504 onaccess port490 may thereby eliminate the need for a separate light source within the body cavity for much of the procedure, reducing the number of access ports that are required.
• [0147]Optical fiber504 may be mounted to accessport490 in various ways. In addition to the annular arrangement of FIGS.37-40,optical fibers504′ may also be mounted along one side oflumen498′, in a crescent-shapedchannel516 extending throughcannula492′, as shown in FIG. 41. Multiple channels (not shown) may extend along two or more sides oflumen498 among whichoptical fibers504 may be distributed. Alternatively, as shown in FIGS.42A-42B, instead of mounting optical fibers to the access port, an openaxial channel518 may extend throughcannula492″ through which an endoscopic light wand or thoracoscope (not shown) having a light source mounted to it may be slidably inserted into the body cavity alongsidelumen498″.
• The access ports of FIGS.[0148]37-42 may also include any of the features of the access ports described above in connection with FIGS.27-29, including having a suture organizer mounted to the proximal end of the access port for retaining sutures in an organized manner aroundlumen498, or having a selectively deployable retention device mounted near the distal end of the access port for engaging the inner wall of the chest (or other body cavity) to maintain the access port in position.
• While the above is a complete description of the preferred embodiments of the invention, various alternatives, substitutions, modifications and improvements are possible without departing from the scope hereof, which is defined by the following claims.[0149]

Claims (20)

What is claimed is:

1. A method of accessing an internal chamber of the heart through a vessel having a lumen in fluid communication with the chamber, the heart and the vessel being within a patient's chest defined by a plurality of ribs connected to a sternum, the method comprising:

positioning an instrument into an inner lumen of the vessel through a penetration in a wall thereof, a proximal end of the instrument extending out of the patient's chest through a percutaneous access port between two adjacent ribs; and

manipulating the proximal end of the instrument to advance a distal end of the instrument through the vessel and into the internal chamber of the heart;

wherein all manipulations of the instrument are performed outside of the patient's chest.

2. The method ofclaim 1 wherein the vessel comprises an aorta and the internal chamber comprises a left ventricle, the step of manipulating comprising passing the distal end of the instrument through an aortic valve disposed in an aortic position between the aorta and the left ventricle.

3. The method ofclaim 2 further comprising attaching a valve prosthesis at the aortic position.

4. The method ofclaim 3 wherein the instrument comprises a suturing instrument, further comprising applying sutures to an annulus of the aortic valve using the suturing instrument.

5. The method ofclaim 3 wherein the step of attaching a valve prosthesis comprises positioning the valve prosthesis through a percutaneous access port between two adjacent ribs.

6. The method ofclaim 3 wherein the valve prosthesis is positioned at the aortic position using a delivery handle removably coupled to the valve prosthesis, the delivery handle being manipulated at a proximal end thereof which extends out of the patient's chest through a percutaneous access port between two adjacent ribs.

7. The method ofclaim 3 further comprising positioning the valve prosthesis through a percutaneous access port in a first orientation and re-orienting the valve prosthesis within the patient's chest into a second orientation before attachment at the aortic position.

8. The method ofclaim 7 wherein the step of re-orienting comprises manipulating from outside of the patient's chest an actuator on a delivery handle releasably coupled to the valve prosthesis.

9. The method ofclaim 7 wherein the second orientation is approximately perpendicular to the first orientation.

10. The method ofclaim 1 wherein all steps are performed without cutting or removing the ribs or sternum.

11. The method ofclaim 1 further comprising visualizing the vessel through a visualization device positioned in a percutaneous access port between two adjacent ribs.

12. The method of claim I further comprising forming an incision in the vessel using a cutting tool manipulated from outside of the patient's chest.

13. The method ofclaim 12 further comprising retracting the incision open before positioning the instrument in the vessel lumen.

14. The method ofclaim 2 wherein the percutaneous access port is positioned in an intercostal space selected from the first, second, third, or fourth intercostal space on an anterior side of the patient's chest.

15. The method ofclaim 1 wherein the percutaneous access port comprises a cannula having a proximal end outside of the patient's chest, a distal end within th patient's chest exterior to the vessel, and a passage therebetween through which the instrument is positioned.

16. In a valve replacement procedure, a method of positioning a replacement valve in a patient's heart within a patient's chest, the chest being defined by a plurality of ribs, the method comprising:

positioning an access device in the chest between two adjacent ribs, the access device defining an opening into the chest between the ribs and having and an illuminating device mounted adjacent to the opening;

illuminating the interior of the chest with the illuminating the device; and

introducing the replacement valve into the patient's chest through the opening.

17. In a valve replacement procedure, a method of positioning a replacement valve in a patient's heart within a patient's chest, the chest being defined by a plurality of ribs, the method comprising:

positioning the distal end of an illuminating device within the chest through a percutaneous access port between two adjacent ribs;

illuminating the interior of the chest with the illuminating the device; and

introducing the replacement valve into the patient's chest through a percutaneous access port between two adjacent ribs while illuminating the interior of the chest with the illuminating device.

18. An access device for providing a percutaneous passage into a chest cavity through which a replacement cardiac valve may be positioned, the access device comprising:

a device body having proximal and distal ends, the distal end being positionable between two adjacent ribs into the chest, the device body being configured to displace tissue between the ribs so as to define an opening into the chest through which the replacement valve may be positioned without interference; and

an illumination device mounted to the device body so as to illuminate the interior of the chest.

19. An access cannula for providing a percutaneous passage into a chest cavity through which a replacement cardiac valve may be positioned the access cannula comprising:

a cannula body having proximal and distal ends, the distal end being positionable between two adjacent ribs into the chest, and having a lumen between the proximal and distal ends through which the replacement valve may be positioned into the chest; and

a light-conducting element mounted to the cannula body and extending from outside the chest to the distal end of the cannula body for illuminating the interior of the chest.

20. In a valve replacement procedure, a method of positioning a replacement valve in an aortic position of a patient's heart within a patient's chest, the aortic position being disposed between a left ventricle of the heart and an aorta leading away from the heart, the chest being defined by a plurality of ribs connected to a sternum, the method comprising:

introducing the replacement valve into the patient's chest through a percutaneous access port between two adjacent ribs; and

positioning the replacement valve through a penetration in the aorta and into the aortic position by manipulating a valve-positioning instrument which engages the replacement valve, wherein all manipulation of the valve-engaging instrument is performed outside of the chest.

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