Open vessel sealing instrument with cutting mechanism

IS 2 370 723 T3

DESCRIPTION

Open blood vessel welding instrument with cutting mechanism

BACKGROUND

The present invention relates to forceps or forceps used in open surgical operations. More particularly, the present invention relates to forceps that apply a combination of mechanical clamping pressure and electrosurgical energy to seal or weld tissue and a selectively advanced blade or blade to cut tissue along the joint. tissue seal.

Technical Field

Tweezers are a tweezers-like instrument that is based on the mechanical action between its jaws to grasp, hold and compress or strangle vessels or tissues. So-called "open forceps" are commonly used in open surgical operations, while "endoscopic forceps" or "laparoscopic forceps" are used, as the name suggests, for less aggressive endoscopic surgical operations. Electrosurgical forceps (open or endoscopic) use both mechanical clamping action and electrical energy to effect hemostasis by heating tissue and blood vessels to coagulate and / or cauterize tissue.

Certain surgical operations require more than just cauterization of tissue and rely on the unique combination of clamping pressure, precise control of electrosurgical energy, and separation distance (i.e., distance between opposing jaw members when closed around to tissue) to "seal" tissue, vessels, and certain vascular bundles.

Vessel sealing or tissue sealing is a recently developed technology that uses a unique combination of radio frequency energy, pressure, and grip control to effectively seal or melt a tissue between two opposing jaw members or sealing plates. Clogging of vessels or tissue is more than a "cauterization" that involves the use of heat to destroy tissue (also called "diathermy" or "electrodiathermy"). Vessel clogging is also more than “coagulation,” which is a tissue dissection process in which tissue cells are ruptured or dried. "Vessel plugging" is defined as the process of liquefaction of collagen, elastin, and basic substances in tissue such that the tissue transforms into a melt with significantly reduced demarcation between opposing tissue structures.

In order to effectively "seal or weld" tissue or vessels, two predominant mechanical parameters must be accurately controlled: 1) the pressure or closing force applied to the vessel or tissue; and 2) the separation distance between the conductive surfaces (electrodes) in contact with the tissue. As can be seen, these two parameters are affected by the thickness of the tissue that is being sealed. The precise application of pressure is important for several reasons: to reduce the impedance of the tissue to a value low enough to allow sufficient electrosurgical energy to pass through the tissue; to overcome expansion forces during tissue heating; and to contribute to the final thickness of the fabric, which is an indication of a good gasket. A good gasket for certain fabrics has been determined to be optimal between about 0.03mm and 0.16mm.

With respect to smaller vessels or tissue, the applied pressure is less relevant and the separation distance between electrically conductive surfaces is more significant for effective sealing. In other words, the chances of the two electrically conductive surfaces touching during activation increase as the thickness of the tissue and vessels becomes less.

Commonly owned United States Patent No. 6,511,480, PCT Patent Application Nos. PCT / US01 / 11420 (WO 02080797) and PCT / US01 / 11218 (WO 02080793), United States Patent Application Nos. Series 10 / 116,824 (US 2003 014053), 10 / 284,562 (US 2003 199869) and 10 / 299,650 (US 2003 109835) all describe various open surgical forceps that seal tissue and vessels. In addition, several journal articles have discussed methods of plugging small blood vessels using electrosurgery. An article titled Coagulation Studies and the Development of a Computerized Automatic Bipolar Coagulator, J. Neurosurg., Volume 75, July 1991, describes a bipolar coagulator that is used to seal small blood vessels. The article states that it is not possible to safely coagulate arteries with a diameter greater than 2 to 2.5 mm. A second article entitled Automatically Controlled Bipolar Electro-coagulation - “COA-COMP”, Neurosurg. Rev. (1984), pp. 187-190, describes a method of terminating electrosurgical energy to the vessel so that charring of the vessel walls can be avoided.

Typically and particularly with respect to open surgical operations, once a vessel has been sealed, the surgeon has to remove the obturation instrument from the operative site, replace it with a new instrument, and precisely cut the vessel along the joint. newly formed tissue seal. As can be seen, this additional step can be both cumbersome (particularly when a significant number of

ES 2 370 723 T3 of vessels) as it may contribute to inaccurate tissue separation along the sealing line due to misalignment or misalignment of the cutting instrument along the center of the tissue sealing line.

EP-A-1 532 932 describes electrosurgical forceps for sealing tissue, including a cutting instrument for severing tissue along the newly formed tissue seal.

Many endoscopic vessel sealing instruments have been designed that incorporate a blade or blade member that efficiently cuts through tissue after forming a tissue seal. For example, documents US-A-5 876 ​​401 and US 2003/114850 describe electrosurgical instruments for cauterization and / or welding of tissues, which include a cutting mechanism specially designed for endoscopic operations. Commonly owned United States Application Serial Nos. 10 / 116,944 (US 2002 0/116944) and 10 / 179,863 (US 2003 018331) describe such an endoscopic instrument that effectively seals and cuts tissue along the tissue sealing gasket. Other instruments include blade members or cutting members that simply cut tissue in a mechanical and / or electromechanical manner and are relatively ineffective for vessel sealing purposes.

There is a need to develop open electrosurgical forceps that are simple, reliable and inexpensive to manufacture and that effectively seal or weld tissue and vessels and that allow a surgeon to use the same instrument to effectively cut tissue along the way. length of the newly formed tissue gasket.

SUMMARY

The invention is defined in appended claim 1, with preferred embodiments in the dependent claims.

The present invention relates to open electrosurgical forceps for sealing tissue and includes a pair of first and second handle members, each of which has a jaw member disposed at a distal end thereof. The jaw members are movable from a first position in spaced relationship with respect to one another to at least one subsequent position in which the jaw members cooperate to clamp tissue between them. Each of the jaw members includes an electrically conductive sealing plate or sealing surface on an inward turned surface that communicates electrosurgical energy through tissue held therebetween. One of the jaw members includes a blade slot or blade channel defined along a longitudinal length thereof, which is dimensioned to reciprocate a cutting mechanism therealong to section tissue clamped between the jaws. jaw members. An actuator is included to selectively advance the cutting mechanism from a first position, in which the cutting mechanism is disposed proximal to tissue clamped between the jaw members, to at least one subsequent position, in which the mechanism The cutting tool is distally distal to the tissue clamped between the jaw members.

The actuator includes a trigger or trigger that cooperates with a rack and pinion system to advance the cutting mechanism from the first to the second positions through the tissue held between them. The rack and pinion system includes a first gear-like rack associated with the trigger, a second gear-like rack associated with the cutting mechanism; and a pinion arranged between the first and second racks. Preferably, the actuator trigger may be moved proximally, distally, or laterally to advance the cutting mechanism distally through the blade channel. Advantageously, the rack and pinion system is disposed within one of the first and second handle members.

In one embodiment, the clamps include a safety mechanism or safety latch to prevent reciprocating movement of the cutting mechanism when the jaw members are disposed in the first position. The deadbolt may form part of one or both of the jaw members and / or may be integrally associated with the cutting mechanism.

In another embodiment, the grippers include one or more springs that automatically load the cutting mechanism in the first position such that after the cutting mechanism has sectioned tissue clamped between the jaw members, the cutting mechanism automatically returns. to the first position. Preferably, the cutter mechanism includes at least one spring to automatically return the cutter mechanism to the first position.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the mechanism in question are described herein with reference to the drawings, in which:

Figure 1 is a perspective view from the left of an open grippers with a cutting mechanism in accordance with the present invention;

Figure 2 is a left side view of the tweezers of Figure 1;

IS 2 370 723 T3

Figure 3 is an internal perspective view of the clamps of Figure 1 showing a rack and pinion actuation mechanism to advance the cutting mechanism and a series of internally arranged electrical connections to activate the clamps;

Figure 4 is an internal side view of the clamps showing the rack and pinion actuation mechanism and the internally arranged electrical connections;

Figure 5 is an enlarged perspective view showing the area of ​​detail of Figure 2;

Figure 6 is an enlarged perspective view showing the area of ​​detail of Figure 3;

Figure 7 is a perspective view of the clamps of Figure 1 with parts separated;

Figure 8 is a perspective view of a handle of the tweezers of Figure 1;

Figure 9 is an enlarged perspective view showing the area of ​​detail of Figure 8;

Figure 10 is an enlarged perspective view of the cutting mechanism;

Figure 11 is a side cross section along lines 11-11 of Figure 10;

Figure 12 is an enlarged perspective view of the detail area of ​​Figure 10;

Figure 13 is a greatly enlarged perspective view of a distal electrical connector of the forceps of Figure 1;

Figure 14 is an enlarged left perspective view of one of the jaw members of the grippers of Figure 1;

Figure 15 is an enlarged right perspective view of the jaw member of Figure 14;

Figure 16 is a side cross-sectional view showing the forceps in an open configuration for grasping tissue;

Figure 17 is a cross-sectional side view showing the area of ​​detail of Figure 16;

Figure 18 is a rear perspective view of the forceps of Figure 1 shown grasping tissue with a ratchet mechanism shown prior to engagement;

Figure 19 is a rear view of the pliers of Figure 1 showing the ratcheting mechanism engaged:

Figure 20 is a greatly enlarged side cross-sectional view showing the clamps in a closed position and defining a gap distance "G" between opposing jaw members.

Figure 21 is a greatly enlarged perspective view of a tissue seal,

Figure 22 is a cross-sectional side view taken along line 22-22 of Figure 21;

Figure 23 is a cross-sectional side view showing the clamps in a closed position and showing activation and advancement of the cutting mechanism;

Figure 24 is an enlarged view of the area of ​​detail of Figure 24; Y

Figure 25 is a greatly enlarged cross-sectional view showing tissue separated along the tissue seal after advancement of the cutting mechanism.

DETAILED DESCRIPTION

Referring to Figures 1-7, forceps for use with open surgical operations include elongated shaft or handle portions 12a and 12b, each of which has a proximal end 14a and 14b and a distal end 16a and 16b, respectively. In the drawings and in the descriptions that follow, the term "proximal", as usual, will refer to the end of the forceps 10 that is closest to the user, while the term "distal" will refer to the end that is furthest away. of the user.

The forceps 10 include an end effector assembly 100 that attaches to the distal ends 16a and 16b of the handles 12a and 12b, respectively. As explained in more detail below, the end effector assembly 100 includes a pair of opposing jaw members 110 and 120 that are connected in an interlocking fashion.

ES 2 370 723 T3 pivoting about a pivoting pin 65 and which are movable relative to each other to clamp the tissue between them.

Preferably, each handle 12a and 12b includes a handle 15 and 17, respectively, disposed at the proximal end 14a and 14b thereof, each consisting of a finger hole 15a and 17a, respectively, through the finger. , to receive a finger from the user. As can be appreciated, the finger holes 15a and 17a facilitate movement of the handles 12a and 12b relative to each other, which in turn pivots the jaw members 110 and 120 from an open position, into position. wherein the jaw members 110 and 120 are disposed in spaced relationship with respect to one another, to a clamping or closed position, in which the jaw members 110 and 120 cooperate to clamp tissue between them.

As best seen in FIG. 7, the handle 12b is constructed of two components, namely 12b1 and 12b2, which mate with one another around the distal end 16a of the handle 12a to form the handle 12b. It is contemplated that the two component halves 12b1 and 12b2 may be ultrasonically welded together at a plurality of different weld points, or the component halves 12b1 and 12b2 may be mechanically coupled in any other known manner, such as by snap, glue, screwing, etc. After component halves 12b1 and 12b2 have been welded together to form handle 12b, handle 12a is secured around pivot 65 and positioned within cutout or relief portion 21 defined within handle portion 12b2 such that the handle 12a is movable relative to handle 121b. More particularly, when the user moves the handle 12a relative to the handle 12b to close or open the jaw members 110 and 120, the distal portion of the handle 12a moves into the cutout 21 formed within the portion 12b2. It is contemplated that configuring the two handles 12a and 12b in such a manner facilitates gripping and reduces the overall size of the forceps 10, which is especially advantageous during small cavity surgeries.

As best illustrated in Figure 1, one of the handles, for example 12b, includes a proximal handle connector 77 that is designed to connect the forceps 10 to an electrosurgical power source such as an electrosurgical generator ( not shown). Proximal handle connector 77 is electromechanically applied to electrosurgical lead 70 such that the user can selectively apply electrosurgical energy as needed. Alternatively, cable 70 can be fed directly into handle 12b.

As explained in more detail below, the distal end of lead 70 connects to a hand switch 50 to allow the user to selectively apply electrosurgical energy as needed to the sealing tissue entrapped between jaw members 110 and 120. More particularly, the interior of the cable 70 houses conductors 71a, 71b and 71c which, upon activation of the hand switch 50, conduct the different electrical potentials from the electrosurgical generator to the jaw members 110 and 120 (see Figures 3 and 4). As can be appreciated, the positioning of the switch 50 in the forceps 10 gives the user more visual and tactile control over the application of electrosurgical energy. These aspects are explained below with respect to explanation of the hand switch 50 and the electrical connections associated therewith.

The two opposing jaw members 110 and 120 of end effector assembly 100 are pivotal about pin 65 from the open position to the closed position to clamp tissue therebetween. Preferably, the pivot pin consists of two component halves 65a and 65b that mate and pivotally secure the handles 12a and 12b during assembly such that the jaw members 110 and 120 can pivot freely between the positions. open and closed. For example, pivot pin 65 may be configured to be spring loaded such that the pivot snaps together in the assembly to secure the two handles 12a and 12b to rotate about pivot pin 65.

The tissue gripping portions of jaw members 110 and 120 are generally symmetrical and include similar component features that cooperate to allow easy rotation about pivot pin 65 to effect tissue gripping and sealing. As a consequence, and unless otherwise indicated, the jaw member 110 and the operating characteristics associated therewith are initially described herein in detail and similar component characteristics with respect to the jaw member 120 will be briefly summarized below. . In addition, many of the features of jaw members 110 and 120 are described in detail in commonly owned United States patent applications Serial Nos. 10 / 284,562 (US 2003 199869), 10 / 116,824 (US 2003 014053). ), 09 / 425,969 (US 6511480), 09 / 178,027 (US 6277117) and PCT application Serial number PCT / US01 / 11420 (WO02080747).

As best shown in Figures 14 and 15, jaw member 110 includes an insulated outer housing 116 that is dimensioned to mechanically engage an electrically conductive sealing surface 112. Insulated outer housing 116 extends the entire length of length of jaw member 110 to reduce alternating or parasitic currents during sealing and / or incidental tissue burning. Electrically conductive surface 112 conducts electrosurgical energy of a first potential to tissue upon activation of hand switch 50. Insulated outer housing 116 is dimensioned to securely engage electrically conductive sealing surface 112. It is contemplated that this may be achieved by stamping, overmolding, overmolding an electrically conductive stamped blanking plate.

ES 2 370 723 T3 and / or overmolding an injection molded metal sealing plate. Other methods of attaching the sealing surface 112 to the outer housing 116 are described in detail in one or more of the above-identified references. Preferably, jaw members 110 and 120 are made from a conductive, powder-coated material with an insulating coating to reduce eddy current concentrations during sealing.

It is also contemplated that the electrically conductive sealing surface 112 may include an outer peripheral edge having a radius and the insulated outer housing 116 encounters the electrically conductive sealing surface 112 along an adjacent edge that is generally tangential to the radius and / or or join along the radius. Preferably, at the interface, the electrically conductive surface 112 is raised relative to the insulated outer housing 116. Alternatively, jaw member 110 including blanking plate 112 and insulated outer housing 116 may be formed as part of a molding process to facilitate fabrication and assembly. These and other contemplated embodiments are discussed in co-pending, commonly owned PCT application Serial number PCT / US01 / 11412 (WO02080786) and co-pending commonly owned pCt application Serial number PCT / US01 / 11411 ( WO02080785).

Preferably, insulated outer housing 116 and electrically conductive sealing surface 112 are dimensioned to limit and / or reduce many of the known undesirable effects related to tissue sealing, eg, flashover, thermal scattering, and eddy current dissipation. All of the aforementioned and cross-referenced manufacturing techniques produce an electrode having an electrically conductive surface 112 that is essentially surrounded by an insulated outer housing 116.

Similarly, jaw member 120 includes similar elements comprising: an outer housing 126 that engages an electrically conductive sealing surface 122. Electrically conductive sealing surface 122 conducts electrosurgical energy of a second potential to tissue upon activation of the hand switch 50.

It is contemplated that one of the jaw members, for example 120, includes at least one stop member 175 disposed on the inner facing surface of the electrically conductive sealing surface 122 (and / or 112). Alternatively or in addition, stop member 175 may be located adjacent electrically conductive sealing surfaces 112, 122 or proximate pivot pin 65. The abutment member (s) is (are) preferably designed to facilitate grasping and manipulation of tissue and to define a gap "G" between opposing jaw members 110 and 120 during sealing (see Figures 18 and twenty). Preferably, the gap distance during sealing or the distance "G" is within the range of about 0.03 millimeters to about 0.016 millimeters.

A detailed explanation of these and other contemplated stop members 175, as well as various manufacturing and assembly processes for joining, discarding, depositing and / or securing the stop members to the electrically conductive sealing surfaces 112, 122 are described in the application. PCT co-pending, jointly assigned, Serial number PCT / US01 / 11222 (WO 0207627).

As mentioned above, two mechanical factors play an important role in determining the resulting thickness of the sealed tissue and the effectiveness of the seal, that is, the pressure applied between opposing jaw members 110 and 120 and the gap "G" between opposing jaw members 110 and 120 (or opposing sealing surfaces 112 and 122 during activation). It is known that the thickness of the resulting tissue seal cannot be adequately controlled by force alone. In other words, if too much force is applied the sealing surfaces 112 and 122 of the two jaw members 110 and 120 would touch and possibly the short would cause little energy to pass through the tissue, resulting in poor sealing. Too small a force would make the gasket too thick. It is also important to apply the correct force for other reasons: to oppose the walls of the vessel; to reduce the impedance of the tissue to a value low enough to allow sufficient current to pass through the tissue, and to overcome expansion forces during tissue heating, in addition to contributing to the creation of the final required tissue thickness, which it is an indication of a good gasket.

Preferably, sealing surfaces 112 and 122 are relatively flat to avoid current concentrations at sharp edges and to avoid arcing between high points. In addition, and due to the reaction force of the fabric when pressed, the jaw members 110 and 120 are preferably manufactured to resist flexing, that is, tapering along their length, providing a constant pressure to a constant parallel tissue thickness and the thickest proximal portion of jaw members 110 and 120 will resist flexure due to tissue reaction force.

As best seen in Figures 9 and 14, the jaw members 110 and 120 include a blade channel 115 disposed therebetween, which is configured to allow reciprocating movement of a cutting mechanism 80 within it. An example of a blade channel is described in commonly owned United States Patent Application Serial No. 10 / 284,562 (US 2003/199869). Preferably the entire knife channel

IS 2 370 723 T3

115 it is formed when two opposing channel halves 115a and 115b, associated with respective jaw members 110 and 120, come together after grasping the tissue. It is contemplated that the blade channel 115 may have a taper or some other configuration that facilitates or enhances the cutting of tissue during reciprocating or reciprocating movement of the cutting mechanism 80 in the distal direction. In addition, blade channel 115 may be formed with one or more safety features that prevent cutting mechanism 80 from advancing through tissue until jaw members 110 and 120 are closed around tissue.

The arrangement of the handle 12b is slightly different from that of the handle 12a. More particularly, handle 12b is generally hollow to define a chamber 28 therethrough that is dimensioned to house hand switch 50 (and electrical components associated therewith), actuation mechanism 40, and cutter mechanism 80. . As best seen in Figures 3, 4, and 7, actuation mechanism 40 includes a rack and pinion system having first and second gear tracks 42 and 86, respectively, and a pinion to advance the cutting mechanism. 80. More particularly, actuation mechanism 40 includes a finger trigger or pin 43 that is functionally associated with first gear rack 42 such that movement of finger trigger or pin 43 moves first rack 42 in one direction. correspondent. The actuation mechanism 40 mechanically cooperates with a second gear rack 86 that is functionally associated with a actuation bar 89 and which advances the entire cutter mechanism 80, as will be explained in more detail below. Drive bar 89 includes a distal end 81 that is configured to mechanically support cutter blade 87 and that acts as part of a deadbolt mechanism as explained in more detail below.

Disposed between the first and second gear racks 42 and 86, respectively, is a pinion sprocket 45 which mechanically meshes with both gear racks 42 and 86 and converts the proximal movement of the trigger 43 into distal translation of the drive rod. drive 89 and vice versa. More particularly, when the user pulls the trigger 43 in a proximal direction into a predisposed channel 29 in the handle 12b (see arrow "A" in Figure 23), the first rack 42 is translated in a proximal direction, which, in turn, it rotates the pinion gear 45 in a counter-clockwise direction. Rotation of pinion wheel 45 counterclockwise forces second rack 86 to translate drive bar 89 in the distal direction (see arrow "B" in Figure 23), advancing the blade 87 of cutting mechanism 80 through tissue 400 trapped between jaw members 110 and 120, that is, cutting mechanism 80, for example knife, blade, wire, etc., it is advanced through channel 115 upon distal translation of drive rod 89.

It is contemplated that multiple gears or gears with different gear ratios may be employed to reduce surgeon fatigue, which may be associated with advancement of the cutting mechanism 80. Furthermore, it is contemplated that the gear tracks 42 and 86 are configured to include a plurality of gear tooth tracks 43 and 87, respectively, which can be of different lengths to provide additional mechanical advantage for advancing the jaw members 110 and 120 through tissue. The rack and pinion arrangement may be curved for spatial purposes and to facilitate handling and / or to improve the overall ergonomic character of the grippers 10.

A spring 83 may be used within chamber 28 to load the first zipper 42 into its proximal movement in such a way that, upon release of the trigger 43, the force of the spring 83 automatically returns the first zipper to its closest position. distal within channel 29. Of course, spring 83 may be functionally connected to load second rack 86 to achieve the same ends.

Preferably, the trigger 43 includes one or more ergonomically pleasing features that enhance the user's grip and tactile sensation to facilitate actuation of the finger tab 43. Such features can include raised protrusions, rubber inserts, shells and gripping surfaces, and the like. Furthermore, the downward orientation of the trigger 43 is considered to be particularly advantageous, as this orientation tends to minimize accidental or inadvertent activation of the trigger 43 during manipulation. Still further, it is contemplated that integrally associating (molding or otherwise shaping) the trigger 43 and gear rack 42 during the manufacturing process minimizes the number of parts, which, in turn, simplifies the manufacturing process. global montage.

As best seen in Figures 5, 9, 10, 11, 12, 17, 20 and 23, a deadbolt mechanism 200 is associated with actuation assembly 40 and cutter mechanism 80 to prevent advancement of the locking mechanism. cut 80 until jaw members 110 and 120 are positioned and closed around tissue. Other locking or locking mechanisms and features are described in commonly owned United States applications, Serial Nos. 10 / 460,926 (US2004 254573), 10 / 461,550 (US2007 179499), 10 / 462,121 (US2009 250419), and application US Provisional Serial Number 60 / 523,387 (US2005 119655). The deadbolt mechanism includes a series of mutually cooperating elements that work together to prevent unintended firing of the cutter mechanism 80 when the jaw members 110 and 120 are disposed in the open position.

IS 2 370 723 T3

More particularly, distal end 81 of cutter 80 is dimensioned to reciprocate within channel 126b defined at the proximal end of jaw member 120 when jaw members 110 and 120 are disposed in a closed position (see FIG. 9). The proximal end of channel 126b defines a recess or relieved portion 123 therein that includes a forward stop 129 that abuts and prevents advancement of the distal end 81 of cutting mechanism 80 when jaw members 110 and 120 are disposed in the open position (see Figures 9 and 17). The proximal portion of the jaw member 120 also includes a guide slot 124 defined therethrough which allows a terminal connector 150 or a so-called "POGO" pin to run therein upon movement of the jaw members 110 and 120 from the open to the closed position (see Figures 17 and 24). In addition, the proximal end includes an opening 125 defined therethrough which houses the pivot pin 65. Jaw member 110 also includes a channel 126a that aligns with channel 126b when jaw members 110 and 120 are disposed in the closed position around tissue.

As best shown in Figures 17 and 24, which show the jaw members 110 and 120 in open and closed orientations, respectively, the operation of the latch mechanism 200 is easily described. When jaw member 120 is rotated relative to jaw member 110 about pivot 65, a flanged portion 81a of distal end 81 of cutter 80 is slidably incorporated within recess 123 and against stop 129 positioned. at the proximal end of jaw member 120 (see FIG. 12). Stop 129 prevents cutter 80 from moving forward due to unintended actuation of trigger 43. At the same time, terminal connector 150 moves freely within slot 124 upon rotation of jaw members 110 and 120. It is contemplated that terminal connector 150 is seated within aperture 151 within jaw member 110 and runs within slot 124 of jaw member 120 to provide a "sliding" or "brushing" contact to deliver electrosurgical power. to the jaw member 120 during the pivotal movement of the clamps 10 (see FIG. 17). The recess 123 also includes a rim or flange 199 that prevents over-rotation of the handle 12a with respect to the handle 12b. More particularly, and as best appreciated in Figures 9 and 17, flange 199 is dimensioned to abut a stop 201 disposed within clamps 110 when rotated to a fully open position to prevent unintended over-rotation of tweezers 10.

When jaw members 110 and 120 are moved toward the closed position as illustrated in FIG. 24, deadbolt mechanism 200 is automatically disengaged to allow distal advancement of cutting mechanism 80. More particularly, when jaw members 110 and 120 close around tissue, distal end 81 including flanged portion 81a automatically aligns within channels 126a and 126b of jaw members 110 and 120, respectively, to allow selective actuation of the cutter mechanism 80. As shown in Figure 24, distal end 81 advances through channel 126a and 126b, forcing knife blade 87 through knife channel 115 (115a and 115b) to cut tissue. As described above, when actuation flange 43 is released, spring 83 biases actuation rod 89 back toward the most proximal position (not shown), which, in turn, realigns distal end 81 with recess 123 to allow jaw members 110 and 120 to be moved to the open position to release tissue 400.

It is contemplated that the deadbolt mechanism 200 may include one or more electrical or electromechanical sensors (not shown) that prevent the cutting mechanism 80 from advancing through the tissue until the tissue seal has been created. For example, the deadbolt mechanism 200 may include a sensor that, upon completion of a tissue seal, activates a switch (not shown) that unlocks the cutting mechanism 80 for advancement through the tissue.

As best seen in Figures 9 and 10, blade 87 is flexible so that it can easily advance through curved blade channel 115. For example, in distal advancement of cutter 80, cutter blade 87 it will simply flex and run around blade channel 115 through tissue 400 retained between jaw members 110 and 20. A curved blade (not shown) having a similar radius of curvature to that of blade channel 115 such that the blade travels through blade channel 115 without contacting the surfaces of blade channel 115 may also be used.

Figures 1, 2 and 19 show a ratchet 30 for selectively locking jaw members 110 and 120 relative to each other in at least one position during pivoting. A first ratchet interface 31a extends from proximal end 14a of handle member 12a toward a second ratchet interface 31b at proximal end 14b of handle 12b in general vertical registration therewith, such that the facing inner surfaces of each pawl 31a and 31b abut one another as jaw members 110 and 120 close around tissue 400. It is contemplated that each ratchet interface 31a and 31b may include a plurality of step-like tabs (not shown) protruding from the inner facing surface of each ratchet interface 31a and 31b such that the ratchet interfaces 31a and 31b interlock in at least one position. Preferably, each position associated with the cooperating ratchet interfaces 31a and 31b contains a specific, i.e. constant, stress energy in the handle members 12a and 12b, which, in turn, transmit specific closing force to the jaw members. 110 and 120. It is contemplated that the ratchet 30 may include graduations or other visual markings that make it possible for the ratchet to

ES 2 370 723 T3 user quickly and easily find out and control the magnitude of the desired closing force between the jaw members. It is contemplated that the handles 12a and 12b may be manufactured from a particular plastic material that is adjusted to apply a particular closing pressure within the working range specified above to the jaw members 110 and 120 when ratcheted. As can be appreciated, this simplifies the manufacturing process and eliminates underpressure or overpressure of jaw members 110 and 120 during the sealing process. Proximal connector 77 may include a stopper or boss 63 (see FIG. 7) that prevents the user from over pressing jaw members 110 and 120 by crushing handle 15 and 17 beyond the ratcheting positions.

It is contemplated that by making the forceps 10 disposable, the forceps 10 are less likely to be damaged as they are intended for single use and therefore do not require cleaning or re-sterilization. As a consequence, the functionality and consistency of the vital sealing components, for example the conductive surfaces 112 and 122, the stopper member (s) 175, and the insulating housings 126 and 116 will ensure a quality and uniform seal.

Figures 3 and 4 show the electrical details relating to the switch 50. More particularly, and as mentioned above, the cable 70 includes three electrical conductors 71a, 71b and 71c that are fed through the handle 12b. Electrosurgical cable 70 is fed into the bottom of handle 12b and is securely held therein by one or more mechanical interfaces (not shown). Conductor 71c extends directly from wire 70 and connects to jaw member 120 to conduct the second electrical potential thereto. Conductors 71a and 71b extend from cable 70 and connect to a circuit board 52.

Several different types of hand switches 50 are considered, for example switch 50 is a regular push button type switch, but may be configured more as a bistable switch that allows the user to selectively activate the clamps 10 in a variety of different orientations. , that is, activation of multiple orientations, which simplifies activation. One particular type of hand switch is described in commonly owned, copending United States patent application Serial No. 10 / 460,926 (US2004 254 573).

Electrical conductors 71a and 71b are electrically connected to circuit board 52 such that when switch 50 is depressed, a trigger conductor 72 carries the first electrical potential from circuit board 52 to jaw member 110. As mentioned above, the second electrical potential is carried by conductor 71c directly from the generator (not shown) to jaw member 120 through terminal connector 150, as previously described. It is contemplated that a switch or safety circuit (not shown) may be employed such that switch 50 cannot be activated unless jaw members 110 and 120 are closed and / or unless jaw members 110 and 120 are closed. 120 have 400 tissue clamped between them. In the latter case, a sensor (not shown) can be used to determine if the tissue is trapped between them. In addition, a sensor mechanism can be employed to determine pre-surgical, concurrent surgical (ie, during surgery), and / or post-surgical conditions. The sensor mechanisms can also be used with a closed-loop feedback system coupled to the electrosurgical generator to regulate electrosurgical energy based on one or more presurgical, concurrent surgical, or postsurgical conditions. Various sensor mechanisms and feedback systems are described in co-pending commonly owned United States Patent Application Serial No. 10 / 427,832 (US2004 015163).

The sensor mechanism (or mechanisms) detects various electrical and physical parameters or properties at the surgical site and communicates with the generator to regulate electrosurgical output. It is contemplated that the sensor mechanism may be configured to measure or "detect" various electrical or electromechanical conditions at the operative site, such as: tissue impedance, changes in tissue impedance, tissue temperature, changes in tissue temperature, leakage currents, applied voltage and applied current. Preferably, the sensor mechanism measures one or more of these conditions continuously or "in real time" such that the generator can continuously modulate the electrosurgical output according to a specific purpose or desired surgical intention. For example, optical sensors, proximity sensors, temperature sensors can be used to detect certain characteristics of the tissue, and electrical sensors can be used to detect other tissue parameters or effects of the operation.

It is contemplated that the sensor mechanism may include a proximity sensor to detect (measure) tissue thickness near the site of operation and generate a tissue thickness value. An initial value of tissue thickness can be provided to the generator as a presurgical parameter. Tissue thickness values ​​detected in real time and / or changes in tissue thickness values ​​over time (A [difference] thickness / A [difference] time) can also be provided to the generator during the surgical process, where The generator modulates the surgical electrical output in accordance with real-time sensed tissue thickness values ​​and / or changes in tissue thickness values ​​over time.

IS 2 370 723 T3

It is further contemplated that additional sensor mechanisms (or the same sensor mechanism with additional capabilities) may be configured to detect initial or changes in tissue moisture (which is often indicative of tissue type) and to generate a value. moisture content and / or determine fabric type based on data of flexibility or optical clarity of the fabric. For example, the sensor mechanism can include an infrared or optical sensor to detect (measure) light or energy generated by a source, such as an infrared source or other light source, that is transmitted through tissue or reflected. from the same, where the detected value is indicative of the moisture content of the tissue and / or the type of tissue in the vicinity of the surgical operation site. A value of the initial moisture content of the tissue and / or tissue type can be provided to the generator as a presurgical parameter. Moisture content values ​​detected in real time and / or moisture content changes over time (A (difference) moisture content / A (difference) time) can also be provided to the generator during the surgical procedure, where the generator modulates the electrical surgical output in accordance with real-time sensed moisture content values ​​and / or changes in moisture content values ​​over time.

In a further useful embodiment, the sensor mechanism (or an additional sensor mechanism) may be configured to detect or monitor surgical properties, states or conditions such as a so-called "pre-surgical condition", a so-called "concurrent surgical condition" and / or a so-called "post-surgical condition." Presurgical conditions include: degrees of tissue opacity in the vicinity of the surgical site; moisture content level of the fabric; and / or tissue thickness. Concurrent conditions include: degree of tissue opacity in the vicinity of the surgical site; moisture content level of the fabric; tissue thickness; tissue temperature; tissue impedance; current through tissue; voltage across tissue; energy through tissue; changes in the degree of opacity of the tissue; changes in the level of moisture content of the fabric; changes in tissue thickness; changes in tissue temperature; changes in tissue impedance; current changes through tissue; changes in voltage across the tissue; and changes in energy across the ejido. Post-surgical conditions include: degree of tissue opacity, in the vicinity of the surgical site; moisture content level of the fabric; tissue thickness; tissue temperature and tissue impedance.

In another particularly useful embodiment, at least one property or condition detected during the post-surgical condition is indicative of the quality of a tissue seal formed during the surgical operation. For example, the sensor module may be configured to include a light detector to detect light generated by a light source and transmitted through (or reflected from) tissue in the vicinity of the surgical site. A proximity sensor having distance sensing elements located on opposite surfaces of the fabric can also be included to detect the distance between the elements, which is indicative of the thickness of the fabric.

As best shown in Figures 1, 2, and 7, a switch cover 53 is located in electromechanical communication with circuit board 52 along one side of handle 12b to facilitate activation of switch 50. As shown As you can see, the position of the switch cap 53 enables the user to easily and selectively energize the jaw members 110 and 120 with one hand. It is contemplated that the switch cover 53 may be hermetically sealed to prevent damage to the circuit board 52 during wet operating conditions. Furthermore, it is contemplated that by locating the switch cap 53 at a point distal to the actuation assembly 40, the overall sealing process is greatly simplified and ergonomically advantageous to the surgeon, i.e., after activation of the The surgeon's finger is automatically moved to actuate actuation assembly 40 to advance cutting mechanism 80. The geometry also prevents inadvertent actuation of the clamps 10 when the clamps 10 are not activated or "power cut off."

The jaw members 110 and 120 are electrically isolated from one another so that electrical energy can be effectively transferred through the tissue to form a tissue seal. Preferably, each jaw member, for example 110, includes a uniquely designed electrosurgical lead path, disposed therethrough, that transmits electrosurgical energy to the electrically conductive sealing surface 112. It is contemplated that the jaw members 110 and 120 may include one or more cable guides or electrical connectors in a kink manner to direct the cable conductors toward electrically conductive sealing surfaces 112 and 122. Preferably, the cable conductors are securely retained along the cable path to allow jaw members 110 and 120 to pivot about pivot 65.

As best shown in Figure 7, the cable conductors 71a, 71b, and 71c are protected by two insulating layers, an outer protective sheath that surrounds the three conductors 71a, 71b, and 71c and a secondary protective sheath that surrounds each single cable conductor, 71a, 71b, and 71c, respectively. The two electrical potentials are isolated from each other by virtue of the insulating sheaths that surround each conductor 71a, 71b and 71c of the cable.

In operation, the surgeon simply uses the two opposing grip members 15 and 17 to clamp tissue between the jaw members 110 and 120. The surgeon then activates the hand switch 50 to provide

ES 2 370 723 T3 electrosurgical energy to each jaw member 110 and 12 to communicate energy through tissue held therebetween to effect tissue sealing (see Figures 21 and 22). Once sealed, the surgeon activates actuation mechanism 40 to advance cutting blade 87 through tissue to section tissue 400 along the tissue seal (see FIG. 25).

From the foregoing, and with reference to the various figures in the drawings, those skilled in the art will appreciate that certain modifications may also be made to the present invention without departing from the scope thereof. For example, although the electrical connections are preferably incorporated within the handle 12b and the clips 10 are intended for right-hand use, it is contemplated that the electrical connections may be incorporated within the other handle 12a, depending on a particular purpose and / or or to facilitate manipulation by a left-handed user. Alternatively, the clamps 10 can be used in an inverted orientation for left-handed users without compromising or restricting any operating characteristics of the clamps 10.

It is also contemplated that the forceps 10 (and / or the electrosurgical generator used in connection with the forceps 10) may include a sensor or feedback mechanism (not shown) that automatically selects the appropriate amount of electrosurgical energy to seal. effectively the particularly sized tissue, trapped between jaw members 110 and 120. The sensor or feedback mechanism may also measure impedance through tissue during sealing and provide an indicator (visual and / or audible) that an effective seal has been created between jaw members 110 and 120. Commonly owned United States Patent Application Serial No. 10 / 427,832 (US2004 015163) discloses several different types of feedback mechanisms and algorithms that can be used for this purpose.

The experimental results suggest that the magnitude of the pressure exerted on the tissue by the sealing surfaces of the jaw members 110 and 120 is important in ensuring a proper surgical result. Pressures on the fabric have been shown to be effective within a working range of about 3 kg / cm² at about 16 kg / cm² and preferably within the working range of 7 kg / cm² at 13 kg / cm², to close arteries and vascular bundles. Pressures on the tissue within the range of about 4 kg / cm² about 10 kg / cm² they have been shown to be particularly effective in the obturation of arteries and tissue bundles. Preferably, the interlocking surfaces 31a and 31b of the pawl 30 are positioned to provide a closure within this working range. Furthermore, and if ratchet 30 includes multiple positions, as discussed above, it is contemplated that each particular ratchet position uses a specific closing force on tissue for particular surgical purposes. For example, handles 12a and 12b can be manufactured such that the spring constants of handle portions 12a and 12b, in combination with the location of ratchet interfaces 31a and 31b, will produce pressures within the above working range. . Successive positions of ratchet interfaces 31a and 31b (and any other positions as described above) increase the closing force between opposing sealing surfaces 112 and 122 incrementally within the above working range.

It is also envisaged that the drive rod 89 may be connected to the same or alternate electrosurgical power source and may be selectively activatable by the surgeon during cutting. As can be appreciated, this would enable the surgeon to electrosurgically cut the tissue along the tissue seal. As a result, an essentially blunt blade can be used to electrosurgically cut tissue. It is also contemplated that an essentially blunt blade with a spring loaded cutting mechanism may be used which, due to the clamping pressure between the opposing jaw members 110 and 120 and due to the force at which the cutting mechanism Spring loaded advances the blade, will cut the tissue along the tissue seal.

It is also contemplated that the clamps may include a blade return safety mechanism (not shown). For example, and as mentioned above, the cutter blade 80 may include one or more springs that automatically return the cutter blade 87 after actuation of the actuator 40. In addition, a manual return may be included that allows the user to manually return the blade 87 should the automatic blade return (eg, spring) fail due to binding, deflection, or some other unforeseen surgical condition. Alternatively, actuation mechanism 40 may be spring loaded and automatically advanced when tab 43 is depressed by the surgeon. After deployment, the surgeon manually retracts switch 43 to reset switch 43 and cutter 80 for further deployment.

Although various embodiments of the invention have been shown in the drawings, the invention is not intended to be limited thereto, as it is intended that the invention be as broad in scope as the art allows and that the specification be read in the same way. . Therefore, the above description is not to be considered as limiting, but merely as exemplifications of preferred embodiments. Other modifications will occur to those skilled in the art within the scope of the claims.