US20020029060A1

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Publication number: US20020029060A1
Application number: US09/765,949
Authority: US
Inventors: Michael Hogendijk
Original assignee: Ethicon Inc
Current assignee: Ethicon Inc
Priority date: 1998-07-29
Filing date: 2001-01-19
Publication date: 2002-03-07
Also published as: US6080175A

Abstract

A surgical cutting instrument adapted for percutaneous insertion into a body cavity to facilitate a minimally invasive surgical procedure. The surgical cutting instrument includes a shaft having a proximal end, an open distal end, and an axial lumen therebetween. An inlet opening may be fluidly coupled to the lumen at a proximal end of the shaft, for connection to a vacuum source for creating a suction force sufficient to retain the distal end of the shaft adjacent to a surface of a body structure within the body cavity. A cutting element is disposed within the lumen of the shaft near the distal end of the shaft, and is operable to cut the body structure without removing any substantial portion of the body structure when the shaft is held adjacent to the surface of the body structure.

Description

TECHNICAL FIELD

The present invention relates generally to instruments for performing minimally invasive surgery, such as minimally invasive cardiac bypass surgery, and more specifically to a surgical cutting instrument adapted for percutaneous insertion into a body cavity of a patient and useful for cutting a body structure within the body cavity, such as a thoracic organ or an artery, vein, or other vessel, without substantially removing any portion of the body structure.[0001]

BACKGROUND ART

Minimally invasive surgical techniques have revolutionized cardiac surgery. Minimally invasive cardiac surgery enjoys the advantages of reduced morbidity, quicker recovery times, and improved cosmesis over conventional open-chest cardiac surgery in which the surgeon “cracks” open a patient's chest by sawing through the breastbone or sternum. Recent advances in endoscopic instruments and percutaneous access to a patient's thoracic cavity have made minimally invasive surgery possible. Reduction in morbidity, lower cost, and reduced trauma has made minimally invasive surgery desirable.[0002]

One approach to minimally invasive cardiac surgery is an endoscopic procedure in which access to the heart is gained through several small openings, or ports, in the chest wall of a patient. The endoscopic method allows surgeons to stop the heart without cracking the chest by utilizing a series of internal catheters to stop blood flow through the aorta and to administer cardioplegia solution to facilitate stopping the heart. The endoscopic approach utilizes groin cannulation to establish cardiopulmonary bypass (CPB) which takes over the function of the heart and lungs by circulating oxygenated blood throughout the body. After CPB is started, an intraaortic balloon catheter that functions as an internal aortic clamp by means of an expandable balloon at its distal end is used to occlude blood flow in the ascending aorta from within. A full description of an example of one preferred endoscopic technique is found in U.S. Pat. No. 5,452,733, the complete disclosure of which is incorporated by reference herein. A primary drawback of endoscopic cardiac surgery procedures, however, is that such procedures do not avoid the damaging effects of CPB. CPB has been shown to be the cause of many of the complications that have been reported in conventional coronary artery bypass graft (CABG) procedures, such as stroke. The period of cardiopulmonary bypass should be minimized, if not avoided altogether, to reduce patient morbidity.[0003]

An approach to minimally invasive cardiac surgery that avoids CPB is minimally invasive direct coronary artery bypass grafting (MIDCAB) on a beating heart. Using this method, the heart typically is accessed through a minithoracotomy (i.e., a 6 to 8 cm incision in the patient's chest) which also avoids the sternal splitting incision of conventional cardiac surgery. The anastomosis procedure is then performed under direct vision on the beating heart. However, there are many obstacles to precise coronary anastomosis during MIDCAB. In particular, the constant translational motion of the heart and bleeding from the opening in the coronary artery hinder precise suture placement in the often tiny coronary vessel.[0004]

In response to problems associated with the above-described minimally invasive surgical techniques, a new surgical platform known as the TRANSARREST™ platform has been developed to minimize the cardiac motion of the beating heart. The TRANSARREST™ platform employs a novel pharmaceutical approach to stabilizing the heart. This revolutionary pharmaceutical approach to cardiac stabilization is fully described in co-pending provisional patent application for Compositions, Apparatus and Methods For Facilitating Surgical Procedures, Serial No. 60/055,127, filed Aug. 8, 1997 and invented by Francis G. Duhaylongsod, M.D, the entire contents of which are expressly incorporated by reference herein. As described therein, pharmaceutical compositions, devices, and methods are provided which are useful for medical and surgical procedures which require precise control of cardiac contraction, such as minimally invasive CABG procedures. Generally, the TRANSARREST™ platform involves the intracoronary administration of a novel drug composition which provides for precise heart rate and rhythm control management while maintaining the ability of the heart to be electrically paced. Electrical pacing wires are connected to the right ventricle and/or left ventricle and/or atria and are used to pace the heart using a novel foot-actuated pacer control system to maintain the patient's blood circulation during the periods in which the surgeon is temporarily not performing the surgical procedure. Thus, for example, in a CABG procedure, the surgeon can control the pacing of the heart with a convenient foot pedal and can controllably stop the heart as sutures are placed in the vessel walls. The pharmaceutical compositions, devices and methods for drug delivery, and systems for pacing the heart, give a surgeon complete control of the beating heart.[0005]

The TRANSARREST™ procedure described above can be used to facilitate any surgical procedure within the thoracic cavity or other body cavity which requires intermittent stoppage of the heart or elimination of movements caused by pulsatile blood flow, whether access is gained to the body cavity via a partial or median sternotomy incision, via a mini-thoracotomy incision, or via one or more small incisions or ports in the chest wall. Ideally, the least invasive manner in which to perform the surgical procedure is through small incisions and/or trocar sleeves disposed in the chest wall, which avoids the morbidity and reduces the pain and trauma associated with open surgical procedures. However, in order to perform the TRANSARREST™ surgical procedure, or any other thoracoscopic procedure, least invasively, new highly specialized microsurgical instruments and methodologies are required since the minimally invasive cardiac surgery field is relatively new and evolving. In particular, a microsurgical cutting instrument is needed which preferably can be inserted into a body cavity percutaneously via a small port incision, accurately manipulated from outside the body cavity, and adapted to be used for extremely small scale microsurgical cutting procedures within the body cavity. Preferably, the surgical cutting tool should be adapted to perform the fine incisions required for an arteriotomy, aortotomy, atriotomy or other similar incision in the tiny coronary vessels, other great vessels of the heart, or peripheral vessels, to facilitate coronary anastomosis, for example. The instrument preferably should be used in concert with remote viewing devices, such as an endoscope, thoracoscope, and the like that can be inserted through small incisions and used to view the operative site.[0006]

Over the past decade, cutting instruments have been developed to facilitate minimally invasive surgical techniques, particularly in the areas of arthroscopy, laproscopy, pelviscopy, and the like. Such procedures typically target large internal body structures and involve both the excision and removal of large masses of body tissue during the surgery. The cutters used for such procedures typically employ some form of rotary or linearly reciprocating device to cut the tissue and vacuum means to remove the tissue from the body cavity, such as in arthroscopic joint procedures. An example of a rotary device used for tissue excision and removal is U.S. Pat. No. 4,203,444 to Bonnell et al. The Bonnell device utilizes an outer tube having a side-facing, axially extending cutting port and an internal rotary blade. A vacuum conduit draws the tissue to be sheared into the cutting port while the rotary blade is driven in shearing relation to the external tube. The vacuum further draws the cut body tissue through a tube lateral to the handle and out of a side port of the instrument for disposal. An example of a linearly reciprocating tissue cutter for excising and removing body tissue during surgery is found in U.S. Pat. No. 5,527,332 to Clement. These cutting instruments, and other similar morcellator-type instruments used for minimally invasive arthroscopic and laproscopic procedures, lack the high degree of precision and control necessary for microsurgical cutting procedures on very small body structures, such as the tiny coronary vessels, and particularly are not well suited for cutting procedures in which it is damaging to remove any substantial portion of the body structure.[0007]

Instruments have been developed to facilitate thoracoscopic CABG and other minimally-invasive microsurgical cutting procedures on small body structures within the thoracic cavity, such as the microsurgical devices described in U.S. Pat. No. 5,501,698. The endoscopic surgical cutting instruments described therein have an end-effector for cutting tissue in the form of forward or rearward-cutting scissors disposed at the distal end of an extended shaft. The scissors are manipulated from the proximal end of the shaft outside the body cavity to make small incisions in a target coronary artery or other vessel or small body structure, which is typically several inches away from the actuating mechanism at the proximal end of the device. The drawback of such cutting devices is that it is difficult to precisely control the cutting motion of the distal end-effector. Because the vessel is several inches away from the proximal end of the device, any slight movement at the proximal end of the tool will cause the distal, cutting end of the tool to jump or bounce, i.e., move in an exaggerated manner. Such surgical cutting tools provide no mechanism to stabilize the distal, cutting end of the tool to precisely control the location, depth, and length of the cut in the target vessel or other small body structure.[0008]

A need therefore exists for a surgical cutting instrument and method to facilitate the performance of minimally-invasive microsurgical procedures, and particularly, the performance of thoracoscopic CABG and other procedures on the heart and coronary and/or peripheral vessels. The surgical cutting instrument preferably should be adapted to be percutaneously inserted into a body cavity, such as the thoracic cavity, through small incisions or trocar sleeves in the chest wall, and simply, quickly, and precisely manipulated from outside the body cavity to make very fine incisions in the coronary vessels (or other small body structure) without substantially removing any portion of the vessels. The surgical cutting instrument must have a length sufficient to reach the heart and other thoracic organs and vessels from various percutaneous access points. Preferably, the surgical cutting instrument should have the capability to stabilize the distal end of the instrument to minimize any unwanted movements of the device during the actual cutting operation.[0009]

SUMMARY OF THE INVENTION

The above mentioned drawbacks of the prior art are overcome by the provision of a surgical cutting instrument ideally suited for minimally invasive surgery, and particularly to minimally invasive CABG procedures on the heart and great vessels. Although features of the present invention have particular utility for minimally invasive cardiac surgery procedures, where access is gained to the heart via small ports in the chest wall, the instruments described herein can be advantageously used in any other cardiac or other surgical procedures, such as conventional open-chest procedures. According to one aspect of the present invention, a surgical cutting instrument is provided which includes an elongate shaft having a proximal end, a distal end adapted for percutaneous insertion into a body cavity within a patient, and an axial lumen therebetween. A stabilizing element is associated with the distal end of the shaft , and a cutting element disposed within the lumen of the shaft near the distal end. The cutting element and the shaft are relatively moveable between a first position and a second cutting position. The cutting element is adapted to cut a body structure within the body cavity when the cutting element and the shaft are in the second cutting position. The stabilizing element, upon actuation, is adapted to maintain the body structure in a stable position adjacent the distal end of the shaft.[0010]

Preferably, the distal end of the shaft has an outside diameter of less than about 5 mm, and the cutting element comprises at least one blade which has a substantially straight cutting edge. Preferably, the cutting edge is displaced at an angle of between about 15 to 30 degrees relative to a vertical axis through the blade.[0011]

The cutting element may be movably disposed within the lumen of the shaft. In this case, the cutting element is fixed to an actuator push rod located within the lumen of the shaft, and connected to an actuator, preferably an actuator button, at a proximal end thereof.[0012]

Alternatively, the shaft may be movably disposed with respect to the cutting element. In this case, the shaft is slidably mounted to a handle of the cutting instrument. An anchor, preferably a rigid rod coaxially disposed within the shaft, fixes the cutting element to the handle. An actuator member mounted to the shaft, and biased by a biasing element, preferably a spring, may be actuated to slide the shaft between first and second positions with respect to the cutting element.[0013]

The cutting element may include at least one blade which is operably coupled to a source of ultrasonic energy. The stabilizing element preferably comprises a vacuum line fluidly coupled to the lumen of the shaft. The vacuum line is adapted to connect to a vacuum source to effect a suction force at the distal end of the shaft. A control mechanism is provided to selectively block flow between the vacuum source and the lumen. The control mechanism may include a slide valve, an on/off button, or other equivalent mechanism for selectively closing and opening the vacuum pathway.[0014]

Alternatively, the stabilizing element may include a gripper assembly associated with the distal end of the shaft and configured to grip a portion of the body structure.[0015]

Additionally or alternatively, at least one electrode may be disposed near the distal end of the shaft to effect or enhance cutting. An electrode may be operatively coupled to the cutting element, preferably substantially colinearly coupled to the cutting edge. A connector is associated with the proximal end of the shaft for electrically coupling the electrode(s) to an electrosurgical power supply.[0016]

An irrigation port may be fluidly coupled to the lumen of the shaft and connectable to a source of irrigation fluid for clearing debris away from the body structure.[0017]

According to a further aspect of the invention, a method for cutting a body structure within a body cavity without removing any substantial portion of the body structure is provided, which includes percutaneously introducing a distal end of a surgical cutting instrument through a percutaneous opening in the body cavity; retaining the distal end relatively immobile with respect to a surface of the body structure; and manipulating the surgical instrument from outside the body cavity to position a cutting element of the surgical cutting instrument in contact with the body structure to cut the body structure.[0018]

Preferably, the retention is accomplished by applying suction through the distal end of the instrument. The manipulation may include actuating an actuator body, externally of the percutaneous opening, to move a cutting element disposed near a distal end of the shaft from a first position to a second, cutting position. The manipulation may include actuating the shaft to move from a first position, in which the shaft substantially covers the cutting element, to a second position in which at least a portion of the cutting element is exposed for cutting the body structure.[0019]

Additionally, radiofrequency energy may be applied to the body structure to facilitate making a cut in the body structure. Ultrasonic energy may be applied to the cutting element to effect or enhance cutting.[0020]

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a surgical cutting instrument constructed in accordance with the principles of the present invention.[0021]

FIG. 2A is a sectional view of the proximal portion of the surgical cutting instrument of FIG. 1.[0022]

FIG. 2B is a sectional view of the proximal portion of a variation of the surgical cutting instrument of FIG. 2A, further including an irrigation feature.[0023]

FIG. 3A is a schematic view of the distal portion of the surgical cutting instrument of FIG. 1 showing the cutting element in a retracted position within the shaft of the instrument.[0024]

FIG. 3B is a schematic view of the distal portion of the surgical cutting instrument of FIG. 1 showing the cutting element extending a short distance beyond the distal end of the shaft in a cutting position.[0025]

FIGS.[0026]4A-4C are side elevational views of three alternative embodiments of the distal portion of the surgical cutting instrument of FIG. 1.

FIG. 5 is a perspective view of a patient during minimally invasive surgery.[0027]

FIG. 6 is a side view of the patient of FIG. 5 prior to insertion of the surgical cutting instrument into the patient's thoracic cavity through one of the percutaneously positioned trocar sleeves.[0028]

FIG. 7 is an illustration of a patient's heart illustrating the use of the instrument of FIG. 1 inserted through a trocar sleeve, and illustrating a transillumination catheter for identifying the blockage in a coronary vessel.[0029]

FIG. 8 is a perspective view of another embodiment of a surgical cutting instrument.[0030]

FIG. 9 is a side cross-sectional view of the proximal portion of the surgical cutting instrument of FIG. 8.[0031]

FIG. 10 is a schematic view of the distal portion of the surgical cutting instrument of FIG. 8 showing the cutting element extending a short distance beyond the distal end of the shaft after the shaft has been moved axially over the cutting element.[0032]

FIG. 11 is a perspective view of a further embodiment of a surgical cutting instrument.[0033]

FIG. 12 is a side cross-sectional view of the proximal portion of the surgical cutting instrument of FIG. 11.[0034]

FIG. 13 is a side cross-sectional view of the vacuum control assembly of the surgical cutting instrument of FIG. 11.[0035]

FIG. 14A is a schematic view of the distal portion of another embodiment of the surgical cutting instrument according to the present invention which employs an ultrasonic transducer.[0036]

FIG. 14B is a partial perspective view of the embodiment of FIG. 14A, which shows the proximal portion of the embodiment.[0037]

FIG. 15 is a block diagram showing an interconnection of elements in the embodiment of FIGS.[0038]14A-B.

FIG. 16 is a perspective view of an embodiment of the present invention which employs a gripper.[0039]

FIG. 17 is a partial sectional view of a proximal portion of the embodiment shown in FIG. 16.[0040]

FIG. 18 is a partial sectional view of a distal portion of the embodiment shown in FIG. 16.[0041]

FIG. 19 is a partial sectional view of a vessel as gripped by the grippers of the embodiment partially shown in FIG. 16.[0042]

DETAILED DESCRIPTION

The devices and methods of the present invention for cutting a body structure such as a blood vessel will now be described in detail. The surgical cutting instruments and methods of the present invention are particularly well-suited for thoracoscopic CABG procedures, in particular for making precise arteriotomy incisions in a diseased coronary vessel, such as a stenosed left anterior descending artery downstream from the stenosis. Although the present invention is particularly well-suited to minimally invasive thoracoscopic procedures, it is to be understood that the invention can be used in any procedure where a fine incision needs to be made with precision and control in any internal body structure, including conventional, open procedures, mini-thoracotomy procedures, and pure endoscopic minimally invasive procedures. For example, the instrument of the present invention may be used for MIDCAB procedures on a beating heart wherein the retention mechanism described below can be used to minimize the motion of the heart to facilitate the cutting procedure.[0043]

A first embodiment of the[0044]

surgical cutting instrument

10 of the present invention is illustrated in FIG. 1. Surgical cuttinginstrument10 includes anouter shaft20 having aproximal end22, an opendistal end24, and anaxial lumen26 between the proximal and distal ends of the shaft20 (see FIG. 2A). Preferably, thedistal end24 of theshaft20 includes a rounded orblunt cap25 made from a clear plastic material to minimize trauma during the introduction of the cuttinginstrument10 into the body cavity and to allow for visual confirmation of the position of the cuttingelement48 withinshaft20.Shaft20 is integrally connected within anaxial bore29 to ahandle30 at theproximal end22 of theshaft20.Handle30 is configured to be grasped by the surgeon to allow the surgeon to grip and support thesurgical cutting instrument10 during surgery.Shaft20 is preferably a rigid, metal or plastic tube having an outer diameter of between about 3 and 10 mm, and preferably between about 3 to 5 mm, so as to fit within a trocar sleeve percutaneously positioned in a patient's chest wall, as will be explained in greater detail below.Shaft20 can also be introduced directly through a percutaneous incision in the chest.Shaft20 must have a sufficient length to reach a target site within a body cavity, such as the heart, from a position outside of the body. Typically,shaft20 will have a length of between about 10 and 30 cm.Shaft20 is shown in the drawings as having a generally circular cross-sectional configuration. However, it is within the scope of the invention forshaft20 to have other configurations, including, but not limited to, square, rectangular, oval, or channel or any other cross-sectional configuration. Additionally,shaft20 could be curved or angled.

Referring now to FIG. 2A, a push-button actuated[0045]

inner cutting assembly

40 is shown which is movably disposed withinshaft20. Cuttingassembly40 includes a cuttingelement48 in the form of a sharpened blade located withinshaft20 at the distal end of theshaft20. As shown in FIG. 3A,blade48 is shielded by roundedcap25 in the retracted position of theblade48 to prevent injury to surrounding tissues and internal body structures during insertion of theinstrument10 into a body cavity.Blade48 is fixed to anactuator button44 by apush rod42. Aspring46 is located withinhandle30 betweeninner support31 and aninner surface44aofbutton44, to bias theactuator button44 into the retracted, closed configuration of FIG. 3A in which cuttingelement48 is covered by the distal end ofshaft20. Actuation ofbutton44 by the surgeon will causeblade48 to move axially withinshaft20 to protrude a slight distance beyond thecap25 of theshaft20 for cutting a body structure, as shown in FIG. 3B and as will be explained in greater detail below.

A[0046]

vacuum control assembly

50 is mounted to thehandle30 by threading, welding, brazing or other equivalent mounting method, for creating a suction holding force at the distal end of theshaft20. Thehandle30 is provided with aninternal vacuum lumen52 which connects thevacuum control device54 to theshaft lumen26. Thevacuum control device54 is preferably a vacuum “on/off” mechanism, but may be any other equivalent mechanism that operates to selectively open and close the vacuum pathway provided byinternal vacuum lumen52. A CLIPPARD MINIMATIC® three way poppet valve, Model No. MAV-3, Cincinnati, Ohio, is a preferred vacuum control device for use in the vacuum control assembly, and threadably engages with thehandle30. Avacuum hose56 connects thevacuum control device54 with an external vacuum source (not shown).

Vacuum applied from the vacuum source is then effectively applied at the distal end of the[0047]

lumen

26 via the pathway provided by

components

56,54,52 and26. In the embodiment shown in FIG. 2, the application of vacuum to the distal end of thelumen26 is initiated by pressing “on/off”button51 of thevacuum control device54, and discontinued by releasing the button. Thus, the vacuum “on/off”button51 is operable to connect thevacuum conduit52 to the vacuum source to create a suction force withinshaft lumen26 when thebutton51 is actuated by the user, as will be explained in greater detail below. The suction force created withinlumen26 by actuation of vacuum “on/off”button51 is sufficient to retain a surface of the body structure, such as a blood vessel, adjacent (e.g., in contact with or near) the distal,open end25 ofshaft20 to facilitate the cutting procedure.

Although one configuration of a vacuum control assembly has been disclosed, it is to be understood that other configurations are within the scope of the present invention. For example, a vacuum control valve, such as a “trumpet”-type valve or slide valve, described below in connection with the embodiment of FIGS.[0048]11-13, or other similar valve mechanism, could be coupled to or incorporated intohandle30 to control the pressure withinshaft20 of surgical cuttinginstrument10.

The[0049]

surgical cutting instrument

10 may further include anirrigation control assembly350 mounted to thehandle30′, by threading, welding, brazing or other equivalent mounting method, as shown in FIG. 2B, for providing an irrigation fluid at the distal end of theshaft20. Thehandle30′ is provided with aninternal irrigation lumen352 which connects theirrigation control device354 to theshaft lumen26. Theirrigation control device354 is preferably an “on/off” mechanism, but may be any other equivalent mechanism that operates to selectively open and close the irrigation fluid pathway provided byinternal irrigation lumen352. A CLIPPARD MINIMATIC® three way poppet valve, Model No. MAV-3, Cincinnati, Ohio, is a preferred irrigation control device for use in the irrigation control assembly, and threadably engages with thehandle30′. Anirrigation hose356 connects theirrigation control device354 with an external source that provides irrigation fluid under pressure (not shown).

Irrigation fluid applied from the external source is then effectively applied at the distal end of the[0050]

lumen

26 via the pathway provided by

components

356,354,352 and26. In the embodiment shown in FIG. 2B, the application of irrigation fluid to the distal end of thelumen26 is initiated by pressing “on/off”button351 of theirrigation control device354, and discontinued by releasing the button. Thus, the irrigation “on/off”button351 is operable to connect theirrigation conduit352 to the external source to create a pressurized flow of irrigation fluid withinshaft lumen26 when thebutton351 is actuated by the user. The irrigation fluid can be used to clear debris away from the body structure to keep the operative field clear during use of the device.

Although one configuration of an irrigation control assembly has been disclosed, it is to be understood that other configurations are within the scope of the present invention. For example, an irrigation control valve, such as a “trumpet”-type valve or slide valve, or other similar valve mechanism, could be coupled to or incorporated into[0051]

handle

30′ to control the pressure withinshaft20 of surgical cuttinginstrument10.

FIGS.[0052]4A-C show various embodiments of the distal end of the cuttingassembly40. As shown in FIG. 4A,blade48 preferably has a sharpenedcutting edge47 along an inner edge thereof. To optimize the cutting action of cuttingedge47, cuttingedge47 is preferably angled from between about 15 and 30 degrees relative to the vertical axis of the blade. As shown in FIG. 4B, anactive electrode49 electrically connected to an electrosurgical power supply (not shown), such as an RF energy power supply, can be soldered, glued or otherwise affixed alongside the back edge ofblade48.Active electrode49 will facilitate making an incision in a body structure by making a small point incision, i.e., a pilot hole, in the body structure when activated by the energy supply. In such a configuration, a return, ground electrode in the form of a dispersive electrode pad (not shown) can be connected to an external surface of the patient's body to provide an electrically conductive path from the active electrode to the return electrode, as would be conventional in the art of electrocautery. The pilot hole made by the energizedactive electrode49 can then be expanded by the shearing action of cuttingblade48 to make a precise cut in the desired body structure, such as ablood vessel43. As illustrated in FIG. 4C, the distal end ofshaft20 may have various configurations to facilitate the cutting action ofblade48. For example, as shown in FIG. 4C, thecap25 at the distal end ofshaft20 can have a notchedhead configuration21 which is configured to pinch or squeeze the body structure intoshaft20

adjacent blade

48. The squeezing action of notchedhead21 brings the desired tissue segment into close proximity toblade48, which can then be plunged into the pinched tissue segment to facilitate the cutting operation.

Although a few various configurations of the cutting[0053]

element

48 and thedistal end24 ofshaft20 have been disclosed in the drawings, it is to be understood that the invention is not limited to the foregoing configurations. For example, theshaft20 could be provided with an integral gripping element, such as, for example, that described below with regard to the embodiment shown in FIGS.16-19. In addition, cuttingelement48 can have various configurations. For example, the cutting element can be in the form of anultrasonic scalpel448, as shown in FIG. 14A.

The[0054]

ultrasonic scalpel

448 is energized by a tool tipultrasonic transducer450 which is electrically connected to an ultrasonic generator452 (shown schematically in FIG. 15) that is external of the tool. Theultrasonic transducer450 vibrates (preferably longitudinally) to transmit the vibration to theultrasonic scalpel448 at a controlled ultrasonic frequency. Theultrasonic transducer450 may include a piezoelectric crystal or a magneto-restrictive transducer that is capable of being electromagnetically excited. Theultrasonic transducer450 is electrically connected to theultrasonic generator452 through theshaft20 and handle430. Anelectrical line434 leads fromhandle430 to connect with the ultrasonic generator452 (not shown in FIG. 14B). The ultrasonic generator contains a switch (not shown) that allows the operator to “on/off” control the application of ultrasonic vibrations to theultrasonic scalpel448. Such a configuration could allow division of tissues with low heat, producing minimal vaporized tissue compared with the electrocautery approach of FIG. 4B.

Although an actuator in the form of a sliding push button ([0055]44,44′) has been described in representative embodiments, various types of actuator mechanisms may be used to slide cuttingelement48 with respect toshaft20 and handle30, including, for example, a plunger mechanism, a rotatable knob that converts rotational motion into axial motion, or a motor-driven linear actuator mechanism.

FIGS. 5 through 7 illustrate a representative thoracoscopic cutting procedure according to the present invention. While a preferred method of performing a coronary artery anastomosis in a thoracoscopic CABG procedure will be described below, it is to be understood that the principles of the present invention may be applied to a wide variety of surgical procedures, both conventional, open procedures, as well as minimally invasive procedures. After placing a patient under general anesthesia, the patient's left lung is deflated using conventional techniques. Multiple small percutaneous incisions are made in the chest wall for the receipt of surgical instruments. As used herein, the term “percutaneous” refers to any penetration through the skin of the patient, whether in the form of a small cut, incision, hole, cannula, trocar sleeve or the like, which is preferably made in an interstitial space between the ribs of the patient. For example, two small incisions are made in the[0056]

chest wall

60 of a patient62 at different interstitial positions between the patient's ribs, while a third incision is made just below the sternum. Afirst trocar64 or other access device is inserted into the first incision at one of the interstices and asecond trocar66 is inserted into the second incision. Athird trocar68 is inserted into the third incision just below the sternum. Each trocar is conventional and includes a central conduit (not shown) for the insertion of surgical instruments, tubes, etc. An example of a trocar which can be used in the present invention is a “THORACOPORT”™ 5 mm trocar manufactured by United States Surgical Corporation of Norwalk, Conn. Once the trocars are installed, a conventional viewing device such as an endoscope, thoracoscope or other viewing instrument is inserted into one of the trocars for viewing of the operative site within the internal thoracic cavity during the surgical procedure.

The invention will now be described in reference to making an arteriotomy incision in a diseased right coronary artery downstream from a blockage, or stenosis, in the artery during a coronary anastomosis procedure. The heart is schematically represented in FIG. 7. Very generally, the heart includes an[0057]

aorta

79 which supplies blood to the major organs of the body, left and right

subclavian arteries

76 and77, respectively, which supply blood from the aorta to the arms and other upper portions of the body, a left71 and rightcoronary artery72 which provide blood to the heart itself, as well as marginal branches off of the left and right coronary artery, such asmarginal branch78 shown with ablockage80. Conventional coronary bypass graft procedures first require that a source of arterial blood be prepared for subsequent bypass connection to the diseased artery. An arterial graft can be used to provide a source of blood flow, or a free graft vessel can be used and connected at the proximal end to a source of blood flow. Preferably, the source of blood flow is any one of a number of existing arteries that are dissected in preparation for the bypass graft procedure. In many instances, it is preferred to use either the left or right internal thoracic artery (not shown). In multiple bypass situations, it may be preferable to use free graft vessels such as the saphenous vein, gastroepiploic artery in the abdomen, and other arteries harvested from the patient's body. If a free graft vessel is used, the upstream end (proximal) of the dissected vessel is connected to theaorta79 to provide the desired bypass blood flow, and the downstream end (distal) of the dissected vessel will be connected to the diseased target vessel in a distal anastomosis.

The target bypass graft vessel can be dissected and prepared for coronary anastomosis using a conventional electrosurgical instrument (not shown) and a viewing scope introduced through any one of the trocars in the[0058]

chest wall

60 of the patient62 (FIGS. 5 & 6). A transillumination catheter70 (see FIG. 7) and method such as fully described in co-pending application Ser. No. 09/042,433 filed on Mar. 13, 1998, for “Transillumination Catheter and Method” and invented by Francis G. Duhaylongsod, M.D. and Hugh Narciso, Jr., which is fully incorporated by reference herein, can be used to facilitate the process of locating and manipulating the target bypass graft vessel to identify the vessel prior to dissecting it.

After the bypass graft vessel has been prepared for coronary anastomosis, the heart can be arrested and intermittently electrically paced using the novel TRANSARREST™ system which is fully described in co-pending provisional patent application Serial No. 60/055,127, for “Compositions, Apparatus, and Methods For Facilitating Surgical Procedures,” filed on Aug. 8, 1997, and invented by Francis G. Duhaylongsod, M.D., the entire contents of which are fully incorporated by reference herein.[0059]

Subsequently, an arteriotomy incision is required in the diseased vessel downstream from a blockage in the vessel to facilitate the anastomosis procedure. As shown in FIG. 7, to facilitate locating the[0060]

blockage

80 in one of themarginal branches78 of the rightcoronary artery72 downstream from which an arteriotomy incision is needed, thetransillumination catheter70 described above and in co-pending patent application Ser. No. 09/042,433 can be used. Thetransillumination catheter70 is percutaneously inserted into a peripheral vessel, such as a brachial artery or a femoral artery (not shown), and advanced with the aid of x-ray fluoroscopy or other guidance means, such as transesophageal echocardiography, into the diseased rightcoronary artery72 and/or itsmarginal branch78 to provide illumination of the artery. Alternatively, thetransillumination catheter70 can be placed directly in the rightcoronary artery72 by a surgical technique usingsurgical cutting instrument10 introduced through a trocar sleeve to make an insertion incision in the vessel. Once thecatheter70 is properly positioned in the stenosedmarginal branch78 of rightcoronary artery72, the lateral diffusion of light from the distal end of the catheter will help the surgeon to identify the location of theblockage80. The thicker wall associated with the diseased, calcified portion of the vessel will diminish the amount of light that passes through the vessel to help the surgeon locate where in the vessel to make the arteriotomy incision.

Once the proper location for making the arteriotomy incision is found, the[0061]

surgical cutting instrument

10 is used to make an incision in the artery downstream from the stenosed region. Preferably, thesurgical cutting instrument10 is introduced into the thoracic cavity through one of the trocar sleeves of FIGS. 5 and 6. Alternatively, thesurgical cutting instrument10 can be inserted directly through a percutaneous incision in the chest wall without using a trocar sleeve or other similar introducer device. The use of a trocar sleeve, however, is preferred to provide an open passage into the thoracic cavity and to prevent injury to adjacent tissues and the like during insertion of the instrument. With thesurgical cutting instrument10 positioned adjacent the external surface of a vessel as shown in FIG. 7, the surgeon can push the vacuum “on/off”button51 to create a vacuum withinshaft lumen26. The resultant suction force created at the open,distal end24 of theshaft20 will cause the vessel to be held or retained adjacent (in contact with or near) the distal end of the shaft.

With the vessel so held by the[0062]

surgical cutting instrument

10, the surgeon can then press on theactuator push button44 to cause cuttingelement48 to move axially withinshaft lumen26 along the longitudinal dimension of the shaft. This will causeblade48 to protrude a short distance beyond the distal end of theshaft20 as shown in FIG. 3B.Blade48 will make contact with the wall of the target vessel and thereby make a fine cut in the wall of the vessel. After a cut has been made in the vessel, the surgeon can then release the vacuum “on/off”button51 to turn off the vacuum and release the vessel from engagement with thesurgical cutting instrument10. Subsequent release of theactuator push button44 by the surgeon will cause the cuttingelement48 to be retracted back into theshaft20. This procedure can be repeated one or more times to make an incision of a desired depth and length in the diseased vessel. It is to be understood that the one or more incisions in the vessel can be made with the heart arrested or beating. In the latter case, the suction force created at the distal end of the shaft helps to compensate for and minimize the movement of the target area to be incised.

After the arteriotomy incision is made in the diseased vessel, the bypass graft vessel can be anastomosed to it at the site of the arteriotomy incision using conventional suturing techniques and microsurgical working instruments introduced through the trocar sleeves. Alternatively, the coronary anastomosis procedure can be performed using any one of the novel anastomosis devices and methods described in co-pending patent application Ser. Nos. 09/037,109; 09/037,113 and 09/037,216 for “Anastomosis Device and Method”, each filed on Mar. 9, 1998, the entire contents of which are incorporated by reference herein.[0063]

FIGS.[0064]8-10 illustrate another embodiment of asurgical cutting instrument100 constructed in accordance with the principles of the present invention. The distal, cuttingend portion124 ofinstrument100 has generally the same structure asend structure24 ofinstrument10, with the main difference being that the cuttingelement148 is stationary in this embodiment, with theshaft120 being configured to move in relation to cuttingelement148 upon actuation of the device. With regard to the cutting assembly actuating mechanism located at the proximal portion122 (FIG. 9), the cuttingassembly140 in this embodiment is fixed to handle130. Specifically, the cutting element, or blade,148 is fixed to arigid rod142 at a distal end of the rod. Therod142 is rigidly connected to handle130 at a proximal end of the rod via lockingpin145.

An actuating assembly[0065]160 is connected toshaft120 to position cuttingelement148 in contact with a body structure to be cut. Actuating assembly160 includes anannular actuator body162 which is secured aboutshaft120 near theproximal portion122 of theshaft120. Aspring164 biases theactuator body162 into a closed, retracted position of the device in whichcutting element148 is shielded by the distal end ofshaft120, as shown in FIG. 8. A pair ofslots165 are provided within the proximal end of theshaft120 to enable the shaft to move back and forth withinhandle130 and overrod142. Lockingpin145 is inserted throughslots165 to movably secure theshaft120 to handle130.

A vacuum control assembly[0066]150 is provided in thehandle130 to controllably connect the lumen ofshaft120 with an external vacuum source, for creating a suction holding force at the distal end of theshaft120. Thehandle130 is provided with aninternal vacuum lumen159 which is connected to a vacuum source (not shown) at the proximal end of the handle via avacuum hose156, and which is fluidly coupled toshaft lumen126 at its other end. To fluidly couple the vacuum source toshaft lumen126, a spring-biased vacuum “on/off”button151, which is preferably a slide valve or equivalent “on/off mechanism, is located inhandle130 and interposed between thevacuum lumen159 andshaft lumen126. Aspring158 biases vacuum “on/off”button151 into a closed, “off” configuration, as shown in FIG. 9, for example.

When[0067]

button

151 is actuated by the surgeon, achannel152 formed in the on/offmechanism154 is brought into alignment withvacuum lumen159 to fluidly connect the vacuum source toshaft lumen126. The resultant suction force created withinlumen126 at the distal end of theshaft120 is sufficient to retain a surface of the body structure, such as a blood vessel, adjacent to (e.g., in contact with or near) the distal,open end125 ofshaft120 to facilitate the cutting procedure. Additionally, thesurgical cutting instrument100 can further include an irrigation port similar to that shown in FIG. 2B fluidly coupled to theshaft lumen126 near the proximal end of theshaft120. Alternatively, a valving mechanism similar to on/offmechanism154 may be employed for control of irrigation fluids through the irrigation port. The irrigation port can be configured to be connected to a source of irrigation fluid for clearing debris away from the body structure to keep the operative field clear during use of the device.

In operation of the[0068]

device

100, with the surface of a body structure retained by the distal end ofshaft120 using vacuum control assembly150, a user can then manipulate actuating assembly160 to position the cuttingelement148 in cutting contact with a body structure, as shown schematically in FIG. 10. Specifically, to expose thecutting element148 beyond the open, distal end ofshaft120, a user, while holdinghandle130, can place his or her fingers aboutannular button162 and pull the button towards thehandle130 and against the action ofspring164. This will cause theshaft120 to move axially overrod142 to expose the cutting element148 a short distance beyond the distal end of the shaft. The device can now be used for a surgical cutting procedure similar to the embodiment of FIGS.1-3, for example, to make a precise incision in a coronary vessel to facilitate a thoracoscopic anastomosis procedure or other cardiac surgical procedure.

FIGS.[0069]11-13 illustrate another embodiment of asurgical cutting instrument200 constructed in accordance with the principles of the present invention. Again, the distal, cuttingend portion224 ofinstrument200 has generally the same structure as the distalcutting end portion24 of thesurgical instrument10, with the main difference being that the cuttingelement248 is stationary in this embodiment, with theshaft220 being configured to move in relation to cuttingelement248 upon actuation of the device. The cutting assembly actuating mechanism located at theproximal portion222 of theinstrument200, however, is different. Similar tosurgical cutting instrument100,surgical cutting instrument200 includes amain shaft220.Shaft220 is connected to aclear cap member225 at the distal end of the shaft which is sized to shieldblade248 upon insertion of the device into a body cavity, and is connected to a spring-biasedannular end member243 at the proximal end of theshaft220.Shaft220 is slidably coupled to handle230 and is configured to move in a longitudinal path relative to handle230 upon actuation byactuator assembly240, as is described below in connection with FIG. 12.

As shown in FIG. 12,[0070]

actuator assembly

240 includes an actuator lever arm241 which is rotatably connected to handle230 at the proximal end of actuator arm241 via apush pin245 provided in the proximal portion ofhandle230. A pair of actuatingrods247 are fixedly connected to lever arm241 at the distal end of arm241 and are located on either side of the proximal position ofshaft220.Rods247 are configured to engage apush pin249 which is rigidly connected toshaft220.Push pin249 is adapted to slide within a slot244 located through the proximal portion ofrod242.Rod242 is connected to cuttingelement248 at the distal end ofrod242, and is fixedly press-fitted intohandle230 at the proximal end of therod242. In this way,shaft220 is axially movable with respect to bothrod242 and cuttingelement248. For example, as the actuator arm241 is depressed by a surgeon, actuatingrods247

force push pin

249 to move backwards within slot244. This will cause theshaft220 to move axially overrod242 to expose the cutting element248 a short distance beyond the distal end of the shaft. The device can now be used for a surgical cutting procedure similar to the embodiment of FIGS.1-3, for example, to make a precise incision in a coronary vessel to facilitate a thoracoscopic anastomosis procedure or other cardiac surgical procedure. When the lever arm241 is released by the surgeon, aspring246 biases theannular end member243 connected to the proximal end ofshaft220 into a closed, retracted position of the device in whichcutting element248 is shielded by the distal end ofshaft220, as shown in FIG. 11. The device can now safely be removed from the body cavity or positioned at another location within the body cavity to make subsequent incisions.

Alternatively, the[0071]

actuator assembly

240 can be configured withoutpush pin249 and slot244. Instead, theinner surfaces247aof each ofrods247 act as a camming surface which abuts surface243aofend member243. Thus, when a user presses on actuator arm241, camming surfaces247aabut surface243aandforce end member243 along withshaft220, backward to exposed cuttingelement248 at the distal end ofshaft220.

[0072]

Rod

242 is hollow and defines aninner lumen253 which is fluidly coupled to avacuum lumen252 inhandle230 to allow a suction force to be transmitted to the distal end ofshaft220, as will be explained hereafter. Avacuum control assembly250 is shown in FIGS. 12 and 13 for retaining a body structure adjacent to the distal end ofshaft220 in operation ofinstrument200.Vacuum control assembly250 is operably coupled to handle230 andshaft220 for creating a suction holding force at the distal end of theshaft220. Thehandle230 is provided with aninternal vacuum lumen252 which is connected to a vacuum source (not shown) near the proximal end of thehandle230 via avacuum hose256, and which is fluidly coupled toaxial lumen253 inrod242 at its other end. As best seen in FIG. 13, to fluidly couple the vacuum source to lumen243, a spring-biased vacuum “on/off”button251 located inhandle230 is interposed between thevacuum lumen252 andlumen253. Aspring255 biases vacuum “on/off”button251 into a closed, “off” configuration. In the closed, “off” configuration ofvacuum button251 shown in FIG. 13,tubular portion257 ofcontrol device254 substantially impedes the transmittal of a suction force generated by the vacuum source throughlumen252.

When[0073]

button

251 is actuated by the user into an open, “on” configuration, however, asmaller diameter portion258 ofvacuum control device254 is brought into alignment withvacuum lumen252 to fluidly connect the vacuum source toshaft lumen253. Thesmaller diameter portion258 allows the suction force generated by the vacuum source to be transmitted pastportion258 and into and alonglumen253 inrod242. The resultant suction force created withinlumen253 is transmitted to the distal end ofshaft220 and is sufficient to retain a surface of the body structure, such as a blood vessel, adjacent to the distal end ofshaft220 to facilitate the cutting procedure. Additionally, thesurgical cutting instrument200 can further include an irrigation port which may be similar in configuration to the vacuum port of the present embodiment or to that of FIG. 2B. Also, any of the previously described valve mechanisms may be used to control the irrigation fluid flow through the irrigation port and ultimately, through thelumen253 andshaft220. The irrigation port can be configured to be connected to a source of irrigation fluid for clearing debris away from the body structure to keep the operative field clear during use of the device.

FIGS.[0074]16-19 illustrate another embodiment of asurgical cutting instrument500 constructed in accordance with the principles of the present invention. The distal, cuttingend portion524 ofinstrument500 includesgripper assembly536. Thegripper assembly536 preferably includes a pair ofgripper elements538 in the form of flanged armor or other gripping element sized for grasping a body structure, such as a blood vessel, although the invention is not to be so limited. That is, a different number of gripper elements may be employed, e.g., three, two pair, etc., without departing from the inventive concept thereof.

The[0075]

shaft

520 is configured to move in relation to thehandle530 as shown in FIG. 17. Aspring546 is located withinhandle530 betweeninner support531 and aninner surface522aof ashoulder522 that extends fromshaft520, to bias theshaft520 into the retracted position with respect to thehandle530, as shown in FIG. 17. The gripper elements are spaced by a distance “d” from one another that is greater than the inside diameter ofshaft520 whenshaft520 is in the retracted position shown in FIGS. 16 and 17. The gripper elements are fixed (FIG. 18) to aninner shaft560 that is immovably mounted with respect to the handle530 (FIG. 17). Agripper actuator550 is pivotally mounted to handle530 bypivot mount552. The gripper actuator includes acamming surface554 which abutssurface522bofshoulder522 that isopposite surface522a.Thegripper actuator550 is configured so that an operator can squeeze thegripper actuator550 and handle530 together to pivot thegripper actuator550 toward thehandle530, causing thecamming surface554 to force theshoulder522 and hence theshaft520 forward to an extended position with respect to thehandle530.

In the meantime, the[0076]

distal end

520aof theshaft520 abuts thegripper elements538 and forces them closer to one another so that they can slide within the inside diameter of theshaft520, thus causing the gripper elements to assume a “gripping configuration” as shown in FIG. 19. In the “gripping configuration, thegripper elements538 are separated by a distance “g” which is significantly smaller than the distance “d”.

In use, the[0077]

instrument

500 is inserted into a body cavity with thegripper elements538 acting to shield theblade548 from accidental cutting or other damage to body tissues. Once in position, such that gripper members locate on opposite sides of a vessel to be operated upon, the gripper actuator is squeezed by the operator as described above, thereby causing thegripper elements538 to grip thevessel43 as shown in FIG. 19. At this time, thevessel43 is held in a relatively immobile condition with respect to theblade548, at least in the location of the vessel where the operation is intended to be performed.

The[0078]

blade

548 is movably mounted with respect to theinner shaft560 by a mechanism very similar to that described in the first embodiment and shown in FIG. 2B. Although theactuator button44″ is shaped somewhat differently in FIG. 17, it functions the same as

buttons

44 and44′ described above. Thus, once the gripper members have been engaged with the tissue to be operated upon as shown in FIG. 19, for example, the operator may then press theactuator button44″ to extend theblade548 and advance it into the tissue to be cut. When thelever button44″ is released by the operator, thespring46 biases theblade548 away from the tissue and into the retracted position shown in FIG. 16. At this time, theinstrument500 can safely be removed from the body cavity or positioned at another location within the body cavity to make subsequent incisions.

Although the[0079]

gripper assembly

536 is designed to replace the function of the vacuum described above, this embodiment may further include vacuum as described above for purposes of suctioning, etc. Further, theinstrument500 may include irrigation capability using any of the previously described mechanisms for delivering irrigation fluids.

It should be understood that while the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. For example, the surgical cutting instrument of the present invention can be used to make an incision in any body structure located within the body cavity of a patient, including, but not limited to, a heart, a coronary artery, a coronary vein, an aorta, and any peripheral vessel. The surgical cutting instrument can be adapted to make an incision thoracoscopically or otherwise in any peripheral vessel such as, for example, a saphenous vein, a radial artery, a brachial artery, a gastroepiploic artery, and a subclavian artery, to facilitate a coronary anastomosis procedure and/or the surgical introduction of instruments such as drug delivery catheters, intraluminal shunts, electrical pacing wires, and other similar devices into these and other vessels during surgery.[0080]

Therefore, the above description should not be taken as limiting the scope of the invention which is defined by the following claims.[0081]

All references cited herein are incorporated by reference.[0082]

Claims

1. A surgical cutting instrument comprising:

an elongate shaft having a proximal end, a distal end adapted for percutaneous insertion into a body cavity within a patient, and an axial lumen therebetween;

a stabilizing element associated with said distal end of said shaft; and

a cutting element disposed within said lumen of said shaft near said distal end;

wherein said cutting element and said shaft are relatively moveable between a first position and a second cutting position, said cutting element being adapted to cut a body structure within the body cavity when said cutting element and said shaft are in said second cutting position; and

wherein said stabilizing element, upon actuation, is adapted to maintain the body structure in a stable position adjacent said distal end.

2. The surgical cutting instrument ofclaim 1, wherein said instrument is adapted to cut the body structure without removing a substantial portion of the body structure.

3. The surgical cutting instrument ofclaim 1, wherein said distal end has an outside diameter of less than about 5 mm.

4. The surgical cutting instrument ofclaim 1, wherein said cutting element comprises at least one blade which has a substantially straight cutting edge.

5. The surgical instrument ofclaim 4, wherein said cutting edge is displaced at an angle of between about 15 to 30 degrees relative to a vertical axis through the blade.

6. The surgical cutting instrument ofclaim 1, wherein said cutting element is movably disposed within said lumen of said shaft.

7. The surgical cutting instrument ofclaim 6, wherein said cutting element comprises at least one blade fixed to a distal end of an actuator push rod located within said lumen of said shaft.

8. The surgical cutting instrument ofclaim 7, further comprising an actuator button coupled to said actuator push rod at a proximal end of said rod which is operable to move said rod with respect to said shaft to position said cutting element between said first position and said second cutting position.

9. The surgical cutting instrument ofclaim 1, wherein said cutting element comprises at least one blade which is operably coupled to a source of ultrasonic energy.

10. The surgical instrument ofclaim 1, wherein said stabilizing element comprises a vacuum line fluidly coupled to said lumen of said shaft and adapted to connect to a vacuum to effect a suction force at said distal end.

11. The surgical cutting instrument ofclaim 1, wherein said body structure is selected from the group consisting of a heart, a coronary artery, a coronary vein, an aorta, and a peripheral vessel.

12. The surgical cutting instrument ofclaim 11, wherein said peripheral vessel is selected from the group consisting of a saphenous vein, a radial artery, a brachial artery, a gastroepiploic artery, and a subclavian artery.

13. The surgical cutting instrument ofclaim 1, wherein the body cavity comprises a thoracic cavity.

14. The surgical cutting instrument ofclaim 1, further comprising at least one electrode disposed near said distal end of said shaft.

15. The surgical cutting instrument ofclaim 14, further comprising a connector associated with said proximal end of said shaft for electrically coupling said electrode to an electrosurgical power supply.

16. The surgical cutting instrument ofclaim 1, wherein said stabilizing element comprises a gripper assembly associated with said distal end of said shaft and configured to grip a portion of the body structure.

17. The surgical cutting instrument ofclaim 1, further comprising a handle connected to said proximal end of said shaft and adapted to be held by at least one hand of a user.

18. The surgical cutting instrument ofclaim 1, further comprising an irrigation port fluidly coupled to said lumen near said proximal end of said shaft, said irrigation port being connectable to a source of irrigation fluid for clearing debris away from the body structure.

19. The surgical cutting instrument ofclaim 8, further comprising a biasing element engaging said actuator button.

20. The surgical cutting instrument ofclaim 19, wherein said biasing element comprises a spring.

21. The surgical cutting instrument ofclaim 1, wherein said shaft is movably disposed with respect to said cutting element.

22. The surgical cutting instrument ofclaim 21, further comprising a handle disposed at said proximal end of said shaft, said shaft being slidably mounted to said handle.

23. The surgical cutting instrument ofclaim 22, further comprising an anchor fixedly connecting said cutting element to said handle.

24. The surgical cutting instrument ofclaim 23, wherein said anchor comprises a rod coaxially disposed within said shaft.

25. The surgical cutting instrument ofclaim 21, further comprising an actuator member mounted to said shaft.

26. The surgical cutting instrument ofclaim 25, wherein said actuator member is mounted near said proximal end of said shaft.

27. The surgical cutting instrument ofclaim 25, further comprising a biasing element engaging said actuator member.

28. The surgical cutting instrument ofclaim 27, wherein said biasing element comprises a spring interposed between said actuator member and said handle, wherein said spring biases said shaft to said first position.

29. The surgical instrument ofclaim 1, further comprising an electrode operatively coupled to said cutting element.

30. The surgical instrument ofclaim 5, further comprising an electrode substantially colinearly coupled to said cutting edge.

31. The surgical instrument ofclaim 10, further comprising a control mechanism positionable to block flow between said vacuum source and said lumen.

32. The surgical instrument ofclaim 31, wherein said control mechanism comprises a slide valve.

33. The surgical instrument ofclaim 31, wherein said control mechanism comprises an on/off button.

34. The surgical cutting instrument ofclaim 21, further comprising a handle disposed at said proximal end of said shaft, said proximal end of said shaft being slidably mounted within said handle.

35. The surgical cutting instrument ofclaim 34, further comprising an anchor fixedly connecting said cutting element to said handle.

36. The surgical cutting instrument ofclaim 35, wherein said anchor comprises a rod coaxially disposed within said shaft.

37. The surgical cutting instrument ofclaim 25, further comprising a lever mounted to said handle and movable to engage said actuator member to move said shaft between said first position and said second cutting position.

38. A surgical cutting instrument adapted for percutaneous insertion into a body cavity within a patient comprising:

an elongate shaft having a proximal end, a distal end, and an axial lumen therebetween;

means for retaining the distal end of the shaft adjacent to or near a surface of a body structure within said body cavity;

a cutting element disposed within said lumen of said shaft near the distal end of the shaft; and

an actuator member disposed near the proximal end of the shaft which is operable to position the cutting element in contact with said body structure for cutting said body structure without substantially removing any portion of said body structure when said retaining means holds said shaft adjacent to or near said body structure.

39. The surgical cutting instrument ofclaim 38 wherein said shaft is moveable between a first position and a second position and is adapted to substantially cover the cutting element when in said first position and to expose at least a portion of the cutting element when in said second position.

40. The surgical cutting instrument ofclaim 38 wherein said cutting element is moveable between a first position and a second position, said shaft substantially covering said cutting element in said first position, and at least a portion of said cutting element extending from said distal end of said shaft in said second position.

41. The surgical cutting instrument ofclaim 39, wherein said actuator member includes an actuator body fixed to said shaft near said proximal end of said shaft and operable to move said shaft between said first position and said second position.

42. The surgical cutting instrument ofclaim 41 further including a spring coupled to said actuator body for biasing said shaft into said first position.

43. The surgical cutting instrument ofclaim 38, wherein said retaining means comprises a vacuum source fluidly coupled to said lumen of said shaft and operable to produce a suction force at the distal end of the shaft which is sufficient to retain the distal end of the shaft adjacent to or near the surface of the body structure.

44. The surgical cutting instrument ofclaim 38, wherein said retaining means includes a gripper assembly at said distal end of said shaft which is configured to grip a portion of the body structure to retain the body structure adjacent to said distal end.

45. The surgical cutting instrument ofclaim 38, further comprising an irrigation port fluidly coupled to said lumen near said proximal end of said shaft.

46. A surgical cutting instrument comprising:

a shaft having a proximal end, an open distal end, and an axial lumen therebetween;

an inlet opening, fluidly coupled to said lumen at said proximal end of said shaft, connectable to a vacuum source for creating a suction force sufficient to retain said distal end of said shaft adjacent a surface of a body structure within the body cavity; and

a cutting element disposed within said lumen near said distal end;

wherein said shaft is movable between a first position, in which said shaft substantially covers said cutting element, and a second position, in which at least a portion of said cutting element is exposed beyond said open distal end of said shaft.

47. A surgical cutting instrument comprising:

a shaft configured for percutaneous insertion into a body cavity of a patient having a proximal end and a distal end;

a cutting element disposed near the distal end of the shaft;

a retention mechanism coupled to the shaft which is configured to retain the distal end of the shaft adjacent to or near a surface of a body structure within the body cavity; and

actuating means disposed near the proximal end of the shaft for positioning the cutting element in contact with a body structure within said body cavity for cutting said body structure when said shaft is held adjacent to or near the body structure.

48. A method for cutting a body structure within a body cavity without removing any substantial portion of the body structure, the method comprising:

introducing a distal end of a surgical cutting instrument through a percutaneous opening in the body cavity;

retaining said distal end of said shaft relatively immobile with respect to a surface of the body structure; and

manipulating the surgical instrument from outside the body cavity to position a cutting element of said surgical cutting instrument in contact with the body structure to cut the body structure.

49. The method ofclaim 48, wherein said retaining comprises retaining said distal end in abutting engagement with the surface of the body structure.

50. The method ofclaim 49 wherein said retaining comprises applying a suction force to the surface of the body structure.

51. The method ofclaim 50, wherein said retaining comprises applying a suction force through said distal end.

52. The method ofclaim 48 wherein said manipulating comprises actuating an actuator body, externally of said percutaneous opening, to move a cutting element disposed near a distal end of the shaft from a first position to a second, cutting position.

53. The method ofclaim 48 wherein said manipulating comprises actuating said shaft to move from a first position, in which said shaft substantially covers said cutting element, to a second position in which at least a portion of said cutting element is exposed for cutting the body structure.

54. The method ofclaim 48 further comprising applying radiofrequency energy to the body structure to facilitate making a cut in the body structure.

55. The method ofclaim 54 wherein said applying radiofrequency energy includes applying energy to an electrode disposed at or near a distal end of the surgical cutting instrument.

56. The method ofclaim 48 further comprising applying ultrasonic energy to said cutting element to effect or enhance cutting.

57. A method for endoscopically cutting a body structure within a body cavity, the method comprising:

applying a suction force to a surface of the body structure to retain the surface of the body structure adjacent to a distal end of the surgical cutting instrument; and

positioning a cutting element disposed near the distal end of the surgical cutting instrument in contact with the body structure to cut the body structure.

58. The method ofclaim 57, wherein said positioning comprises actuating an actuator body externally of said percutaneous opening, to move said cutting element from a first position to a second, cutting position.

59. The method ofclaim 57, wherein said positioning comprises moving a shaft included as a portion of said surgical cutting instrument, from a first position in which said shaft substantially covers said cutting element, to a second position in which at least a portion of said cutting element is exposed for cutting the body structure.

60. The method ofclaim 57, further comprising applying radiofrequency energy to the body structure to facilitate making a cut in the body structure.

61. The method of claim60, wherein said applying radiofrequency energy includes applying radiofrequency energy to an electrode disposed at or near said distal end of said surgical cutting instrument.

62. The method ofclaim 57, further comprising applying ultrasonic energy to said cutting element.