Tissue closure electrosurgical system and method of use

Abstract

An electro-surgical system to close a tissue opening in tissue layers after removal of a tissue-penetrating instrument. The system includes an electrode assembly with tissue penetrating electrodes in an electrode array for insertion in the tissue layers near the tissue opening. The electrode assembly with penetrating electrodes including an alignment feature for use of the tissue-penetrating instrument as guide for positioning of the electrodes before removal of the tissue-penetrating instrument. Tissue penetrating electrodes can have portions of the surface covered with electrical insulator to avoid delivery of electro-surgical energy to portions of the tissue layers. The electro-surgical system can deliver electro-surgical energy to all electrodes simultaneously or sequentially to selected groups of tissue penetrating electrodes following an activation pattern. The electro-surgical system may be used during any surgical procedure that leaves a tissue opening, including the sclerotomies performed during vitrectomy procedures.

Description

[0001] Description

[0002] Title of Invention: Tissue closure electrosurgical system and method of use

[0003] Background / Summary

[0004] FIELD OF THE INVENTION

[0005] This invention relates generally to invasive surgical procedures, including minimally invasive procedures and, in particular to a system and method for improved closure of incision sites after removal of cannulas and other devices adapted for use in such procedures.

[0006] BACKGROUND OF THE INVENTION

[0007] Many surgical procedures now use trocars and cannulas, or other mechanical hardware devices, to access internal body spaces and cavities. For example, a pointed trocar within a hollow, tubular cannula may be used to pierce tissue layers. The trocar is removed, leaving the cannula as a portal for the subsequent placement of instruments, such as graspers, scissors, staplers, and so forth.

[0008] There are many trocar / cannula systems, and other instruments that allow entry into body cavities with other devices, used for different medical purposes, including laparoscopic abdominal and microsurgical procedures in several surgical sites throughout the body. In each case, when the instruments, cannulas, and / or other entry devices are removed, an open puncture wound remains that often must be closed.

[0009] In some cases, wound closure with sutures, glues, or other substances may be timeconsuming or problematic. During vitrectomy, for example, particularly done with larger- gauge (i.e. , 21 , 23, 25 gauge) instruments, the sclerotomy wounds can leak, forcing the surgeon to close them with suture after the cannula is removed. Some surgeons try to prevent suturing by inserting the trocar at an angle aiming to produce a self-sealing incision. This approach is time consuming and is prone to failure, with a suture required anyway many times.

[0010] The need for a suture can be challenging and tedious, particularly when the conjunctiva bleeds or balloons up and obscures the incision and can result in a significantly more hemorrhagic and inflamed surgical site. Ophthalmic surgeons often must guess where to throw the sutures and apply pressure to the area for up to several minutes to visualize the wounds that need to be closed.

[0011] Even then, the surgeon may have to cut down the conjunctiva to close the scleral wound, which then increases the tissue invasiveness of the procedure and requires additional sutures to close conjunctiva. Similarly, suture or glue closure of an incisional access point made by a laparoscopic cannula or other incision dilation / maintenance device can be difficult, after removal of the cannula or other such device, if there is extensive bleeding and / or tissue swelling that obscures visualization of the wound edges.

[0012] There is an outstanding need for more efficient wound closure devices, systems, and methods to obtain faster and safer closure of tissue openings that remain after removal of tissue penetrating instruments from tissue layers.

[0013] SUMMARY OF THE INVENTION

[0014] The invention improves upon and expedites surgical procedures by providing a system and method to close an opening in tissue layers that can remain after removal of a tissue-penetrating instrument.

[0015] A system according to the invention includes an electrode assembly electrically connected to a bipolar electro-surgical generator. The electrode assembly includes a plurality of tissue penetrating electrodes disposed in an electrode array.

[0016] An operator can actuate over a shank in the electrode assembly using a pushing action to make the electrode array penetrate the tissue layers aligned with the tissue layer opening. Bipolar electro-surgical energy can be applied to the tissue penetrating electrodes following an activation pattern to locally contract the tissue layers surrounding the tissue layer opening causing it to close.

[0017] The electrodes arranged in an electrode array pattern can have portions covered with electrical insulator in a way that bipolar electro-surgical energy is delivered only at selected regions of the tissue layer.

[0018] The tissue penetrating electrodes can flex laterally to follow the tissue penetration sites as they approximate neighbor electrodes due to tissue contraction. This prevents electrode stiffness to oppose the desired tissue contraction effect.

[0019] The electrode assembly can include an alignment feature enabling the use of the tissuepenetrating instrument as a guide before removal. In this way an operator can position the electrode assembly over the tissue opening before removal of the tissue-penetrating instrument. This prevents losing sight of the tissue opening due to tissue layers displacement before placing the electrodes in the desired position.

[0020] If required, the operator can first partially remove the tissue-penetrating instrument through the tissue opening to create a space for a guided orientation followed by insertion of the tissue penetrating electrodes. After this step, the tissue-penetrating instrument can be totally removed from the tissue layers and then bipolar electro- surgical energy can be applied to the inserted electrodes following an activation sequence.

[0021] As used herein, “tissue layer” should be taken to include the conjunctival membrane, the sclera of the eye, the skin and any other tissues or membranes. A method for performing a surgical procedure in accordance with the invention comprises the steps of (1) providing an electrode assembly with tissue penetrating electrodes electrically connected to a bipolar electro-surgical generator, (2) having an operator align the electrode assembly over a tissue opening in tissue layers produced by a tissue penetrating instrument, (3) applying a force to cause the aligned tissue penetrating electrodes to penetrate the tissue layers up to a travel limit position, (4) activating the bipolar electro-surgical generator to deliver bipolar energy to the electrodes in the electrode assembly in a sequence causing contraction of the tissue layers and closure of the tissue opening, and, (5) removing the electrode assembly from the tissue. During step (2) the operator can optionally use an alignment feature in the electrode assembly to use the tissue penetrating instrument as a guide to position the electrode assembly over the tissue opening before removal of the tissue penetrating instrument from the tissue opening.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS:

[0023] FIG.1 A is a schematic representation of one embodiment of the electro-surgical system of the present invention including an electrode assembly.

[0024] FIG. 1 B is an exemplary schematic diagram of a sequencer subsystem capable of energizing the electrode assembly shown in FIG.1A.

[0025] FIG.2A is a side view of a tissue penetrating electrode of the present invention.

[0026] FIG.2B is a side view of an alternative embodiment of a tissue penetrating electrode.

[0027] FIG.3A is a diagonal view of an electrode assembly of the present invention with an electrode array including three tissue penetrating electrodes symmetrically disposed around an alignment slot. FIG.3B is a lateral view of the electrode assembly from FIG.3A.

[0028] FIG.3C is a top view of the electrode assembly from FIG.3A illustrating the equilateral triangular electrode array for use centered around a tissue opening.

[0029] FIG.4 is a diagonal view of another embodiment of the electrode assembly of the present invention incorporating an array of four tissue penetrating electrodes symmetrically disposed around one end of an open alignment slot.

[0030] FIG.5 is a diagonal view of an electrode assembly including an electrode array of four electrodes integrated to a handpiece.

[0031] FIG.6 depicts a top view of an electrode assembly that can be detachably coupled to a handpiece through a rigid joint, shown in a detached condition.

[0032] FIG.7 depicts a top view of the electrode assembly from Fig.6 shown with the rigid joint in attached condition.

[0033] FIG.8 depicts a lateral sectional view of an eye with a tissue penetrating instrument inserted across the conjunctival membrane and across the sclera in operational mode during a vitrectomy procedure.

[0034] FIG.9 depicts the sectional view from FIG.8 with the tissue penetrating instrument partially removed to create a space to aid in the alignment of an electrode assembly from the present invention.

[0035] FIG.10 is the lateral sectional view from FIG.9 now also including a front view of an electrode assembly positioned to use the tissue penetrating device as guide for alignment before insertion of the tissue penetrating electrodes into the target tissue layers. FIG.11 is a perpendicular lateral view from FIG.10 illustrating the electrode assembly aligned using the tissue penetrating instrument as a guide and with the electrode array ready for insertion into the target tissue layers.

[0036] FIG.12 is the view from FIG.11 shown with the tissue penetrating electrode array inserted into the target tissue layers with the tissue penetrating instrument used as guide before removal from the tissue opening.

[0037] FIG.13 is a detail view of the electrode assembly from Fig.10 shown with the tissue penetrating electrode array inserted into the target tissue layers with the tissue penetrating instrument used as guide before removal from the tissue opening.

[0038] FIG.14 is the view from FIG.11 shown with the tissue penetrating electrode array inserted into the target tissue layers after removal of the tissue penetrating instrument from the tissue opening ready for bipolar energy activation.

[0039] FIG.15 illustrates a top view of the electrode assembly in the final operational position after removal of the tissue penetrating instrument and ready for bipolar energy electrode activation.

[0040] FIG.16 is a detail top view of the electrode assembly from FIG.15 positioned ready for electrode activation.

[0041] FIG.17A is a front view of the electrode assembly with the electrodes positioned penetrating the tissue layers ready for electrode activation.

[0042] FIG.17B is a detail view of the electrode assembly from FIG.17A.

[0043] FIG.18A is a top view of an electrode assembly integrated to a handpiece.

[0044] FIG.18B is a cross-sectional side view of the electrode assembly from FIG.18A along line B-B. FIG.19 is a lateral cross-sectional view of an electrode assembly positioned ready for bipolar energy activation to close an opening in a tissue layer created during a vitrectomy procedure.

[0045] FIG.20 is the lateral cross section from FIG.19 after completion of the bipolar energy activation of the tissue penetrating electrodes showing the opening in the tissue layer now closed.

[0046] FIG.21 A is a schematic side view of two contiguous electrodes from an electrode array positioned in the tissue layers ready for electrode activation.

[0047] FIG.21 B shows the two contiguous electrodes from FIG.21 A with their distal ends (pointed by arrows) bent toward each other by contraction of the tissue layer after electrode activation.

[0048] FIG.22 is an inferior diagonal view of an electrode assembly embodiment including protruding pillars around each electrode to locally reduce the thickness of the superficial tissue layer during insertion.

[0049] FIG.23 is an inferior diagonal view of another electrode assembly embodiment incorporating a movable protective shield covering each electrode before tissue penetration.

[0050] FIG.24 is the embodiment from FIG.23 shown with the movable protective shield displaced toward the fixed portion of the electrode base exposing the electrodes distal end.

[0051] FIG.25A is a front view of the electrode assembly shown in FIG.23 with the movable electrode shield covering the electrodes distal ends with shield safety locks in pre-use storage position.

[0052] FIG.25B is a lateral view of the electrode assembly shown in FIG.23 with the movable electrode shield covering the electrodes distal ends. FIG.26A is a front view of the electrode assembly shown in FIG.24 with the movable electrode shield displaced to expose the electrodes distal ends ready for electrode activation.

[0053] FIG.26B is a lateral view of the electrode assembly shown in FIG.24 with the movable electrode shield displaced to expose the electrodes distal ends.

[0054] FIGS.27A, 27B and 27C depict the electrode assembly from FIG.23 incorporating an adjustment feature to limit the travel of the movable electrode shield for an operator to select a desired tissue penetrating depth of the electrodes in the electrode array.

[0055] FIG.28 is a lateral view of the electrode assembly shown in FIG.24 with the exposed portion of the tissue penetrating electrodes inserted into the tissue layers ready for electrode activation.

[0056] FIG.29 illustrates an alternative embodiment including a bipolar energy conditioning circuit.

[0057] FIGURE NUMERALS electro-surgical system 10 display 24 tissue penetrating instrument 12 handpiece 26 electrode assembly 14 shank 28 activation pattern control 15 connector 30 pulse duration control 16 electrode connector 32 loop number control 17 bipolar power signal cable 34 electro-surgical unit 18 electrodes 38 bipolar power control 19 electrode array 42 pulse interval control 20 bipolar power generator 46 footswitch 22 microcontroller 50 system memory 54 rigid joint 118 bipolar power subsystem 56 eye 122 sequencer subsystem 58 vitreous cavity 126 power switch 62 tissue opening 130 power switch control input 63 sclerotomy 134 pole-1 64 canula 138 pole-2 65 head 142 electrically conductive surface 66 tube 146 superficial tissue layer 67 upper portion 150 second tissue layer 68 lower portion 154 scleral tissue layer 70 outer portion 158 first conductive region 71 space 162 second conductive region 72 penetration limiting surface 166 insulator 73 tissue layer compressing pillars 178 electrically insulated surface 74 fixed portion 182 conjunctival membrane layer 78 slidable shield portion 192 electrode base 82 shield safety lock 194 conductor 86 gap 196 electrode proximal end 90 alignment rods 202 electrode distal end 94 alignment hollow cylinders 206 slot 98 latch 208 access point 102 convex protrusion 209 hollow region 106 adjustment screw 210 bottom surface 110 electro-surgical conditioning unit 214 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0058] An embodiment of the present invention is described for use to close a tissue opening 130 also named sclerotomy remaining after removal of tissue penetrating instruments used across a superficial tissue layer 67 called conjunctival membrane layer 78 and a second deeper tissue layer 68 also named scleral tissue layer 70 during a vitrectomy surgery in an eye 122. Other dimensions and configurations can be applied for use of the present invention to close other tissue openings remaining after other surgical procedures that use tissue penetrating instruments.

[0059] An electro-surgical system 10 of the present invention shown in FIG.1 A has an electrode assembly 14 also shown in FIG.1 B that can be connected to an electro- surgical unit 18. Electro-surgical system 10 can be activated by an operator using a footswitch 22, a voice command or other user input. A display 24 can show system settings to an operator.

[0060] Electro-surgical system 10 can also include a handpiece 26 to hold the electrode assembly 14 through a shank 28 and a connector 30 to receive a bipolar power signal cable 34. Electrode assembly 14 has a plurality of electrodes 38 disposed in an electrode array 42. Electro-surgical unit 18 can include a bipolar power subsystem 56 with a bipolar power generator 46 to produce a bipolar voltage signal with an amplitude typically between 0 and 800 volts. The bipolar power level can be adjusted by varying the output voltage and / or the duty cycle between 0 to 100% using a bipolar power control 19. The frequency of operation is typically in the range of 100kHz to 1 MHz. The bipolar power level can also be retrieved by a microcontroller 50 executing a computer program from data stored in a system memory 54 and can include a feedback loop for power adjustment on the fly according to tissue layer electrical resistance as sensed by electrodes 10. The timer-counter section of the Renesas SAM3X8E microcontroller can be used for frequency generation and for PWM adjustments. The bipolar power signal with the selected voltage and duty cycle can be further processed using a sequencer subsystem 58. Sequencer subsystem 58 can have a user actionable activation pattern control 15 to select a pattern of distribution of bipolar power pulses into electrode groups in electrode array 42 from electrode assembly 14. Sequencer 58 can also include a user actionable pulse duration control 16 for selection of the duration of each pulse and a pulse interval control 20 for selection of an idle period between sequential pulses. Sequencer 58 can also include a user actionable loop number control 17 to select the total number of electrode group activation repetitions of the electrodes integrating the selected electrode array 42. As a mode of example, the bipolar electro-surgical energy output consisting in 2 poles of alternating current (pole-1 64 and a pole-2 65) can be distributed into four electrodes A, B, C and D shown in FIG.1 B disposed following electrode array 42 in electrode assembly 14. One or more electrodes in array 42 can receive bipolar energy from pole- 1 while one or more electrodes of the other electrodes in array 42 can receive bipolar energy from pole-2. A power profile, an activation pattern, a pulse duration, and a number of loops can be delivered through sequencer 58. FIG.1 B shows an exemplary schematic circuit used for distribution of bipolar energy into different groups of electrodes 38 from electrode array 42. One or more electrodes can be connected to a power switch 62 having a SPDT ON-OFF-ON configuration. In this way, individual electrodes or groups of electrodes can receive pole-1 64, pole-2 65 or no signal from bipolar power generator 46. SPDT ON-OFF-ON power switch 62 can handle the frequency range used by bipolar electro-surgical instruments and can be operated by microcontroller 50 using several output ports, each connected to a power switch control input 63. One embodiment for a switch 62 consists in two back-to-back power MOSFETs with their gates interconnected and driven by an output port from microcontroller 50 through a MOSFET driver IC.

[0061] Shown in FIG.2A and FIG.2B are tissue penetrating electrodes for use with the present invention. FIG.2A depicts a side view of a preferred embodiment for an electrode 38 for use in the present invention during a vitrectomy procedure. Electrode 38 can have a tubular shape and can terminate in a sharp distal end 94 for effortless tissue layer penetration. Electrodes 38 can have regions with electrically conductive surface 66 for bipolar power delivery into tissue layers, for example the scleral tissue layer 70 from an eye. Electrodes 38 can also have regions with an electrically insulated surface 74 to prevent bipolar power signal delivery into the tissue layers in contact with the insulated surfaces, for example the conjunctival membrane layer 78 from the eye. An electrode proximal end 90 can be fixed to an electrode base 82 integral to electrode assembly 14. Conductors 86 are electrically connected to electrodes 38 proximal ends 90 through connectors 32 providing bipolar power signal from electro-surgical unit 18. A typical electrode 38 effective length for closure of a sclerotomy 134 opening in a vitrectomy can range between 0.30 mm and 1.0 mm. Electrically insulated surface 74 can be in the proximal tubular surface of the exposed electrode for tissue penetration starting from electrode base 82 toward electrode distal end 94 with an insulated exposed length between 0.0 and 0.80 mm. Electrode 38 contours, diameters, length, insulation regions and arrays can vary for different uses in different tissue layers without departing from the present invention.

[0062] Fig.2B depicts another embodiment of an electrode 38 incorporating a second conductive region 72 electrically insulated from a first conductive region 71 by an insulator 73. Each conductive region has a separate electrical connector 32 to receive bipolar power from electro-surgical unit 18. This alternative electrode configuration allows delivery of bipolar energy from pole-1 64 and pole-2 65 into a tissue layer from within a single electrode. The preferred maximum diameter of electrodes 38 can be between 0.03 mm and 0.3 mm when using the present invention to close an opening in the scleral tissue layer 70 of an eye after removal of a tissue penetrating instrument 12 such as a vitrectomy canula 138. These dimensions can vary when using this system to close tissue openings in other parts of the body.

[0063] Among the preferred materials for electrode construction are stainless steel and tungsten. Electrode surface can be treated using conventional non-stick procedures to prevent tissue layer adhesion during bipolar power activation.

[0064] The electrically insulated surfaces 74 of electrodes 38 can be obtained using a plurality of available insulator materials and processes such as insulator enamels for biomedical use, borosilicate glass, parylene deposition and others.

[0065] FIG.3A shows a perspective view of electrode assembly 14 having three electrodes 38 with proximal ends fixated at electrode base 82. The three electrodes 38 are disposed in an equilateral triangular electrode array 42 centered around the closed end of slot 98 where the other end of slot 98 is open to form an access point 102 capable of admitting the longitudinal portion of a tissue penetrating instrument 12. Each electrode 38 is connected to electro-surgical unit 18 through separate conductors 86.

[0066] FIG.3B shows a side view of the exemplary electrode assembly embodiment shown in FIG.3A. The total axial length of each electrode 38 is 2.5 mm. Electrodes 38 diameter is 0.1 mm. A length of 0.5 mm of the proximal end of each electrode 38 is fixated to electrode base 82. The total height of electrode base 82 is 2.0 mm. This leaves an exposed length of electrodes 38 distal end 94 for tissue penetration of 0.5 mm. Electrode base 82 includes a hollow region 106 inside the perimeter circumscribing electrode array 42. This volume coincident with electrode array 42 extends 1 .5 mm upward from the inferior aspect of electrode base 82 providing a space 162 that allows bending of the electrodes 38 toward each other and to the center of array 42.

[0067] FIG.3C is a top view from FIG.3A and depicts electrode assembly 14 with electrode base 82 including an equilateral triangular electrode array 42 with one electrode 38 at each vertex of the triangle. Round ended open slot 98 has a circular end at the center of electrode base 82. The center of the equilateral triangular electrode array 42 coincides with the center of the closed end of open slot 98. In this way electrode base 82 can be positioned around the longitudinal portion of a tissue penetrating instrument 12 for alignment, centration and tissue penetration of electrode array 42 over tissue opening 130 before removal of tissue penetrating instrument 12. A bottom surface 110 of electrode base 82 surrounding the center hollow region 106 determines electrode 38 tissue penetration depth limit by contact with a penetration limiting surface 166. Only the distal portion of electrodes 38 surpassing the bottom surface 166 of electrode base 82 will penetrate the tissue layers.

[0068] Shown in FIG.4 is an alternative embodiment for electrode assembly 14 with electrode base 82 holding four electrodes 38 in a squarely shaped electrode array 42. Conductors 86 provide electrical connection between electrodes 38 and unit 18. The exposed length of the distal end 94 of electrodes 38 for tissue layer penetration is 0.7 mm. In this embodiment the distal portion of electrodes 38 emerges directly from the inferior surface of electrode base 82. The closed end of round ended open slot 98 has its center coincident with the center of the squarely shaped electrode array 42. In this way electrode base 82 can be positioned surrounding the longitudinal portion of a tissue penetrating instrument 12 for alignment, centration, and tissue penetration of electrode array 42 over tissue opening 130 followed by complete removal of tissue penetrating instrument 12 before electrode activation.

[0069] FIG.5 illustrates a perspective view of an electrode assembly 14 that is integral part of a handpiece 26. Conductors 86 and connectors 30 provide electrical connection between electrodes 38 and unit 18 though cable 34.

[0070] Shown in FIG.6 is a top view of an embodiment of electrode assembly 14 including an electrode base 82 that can be detachably coupled to a handpiece 26 through a rigid joint 118 shown here in detached condition. Rigid joint 118 includes electrical contacts for electric continuity of conductors 86 for connection between unit 18 and electrodes 38 through cable 34. FIG.7 illustrates the embodiment from FIG.6 with rigid joint 118 shown in the attached condition affixed to handpiece 26 providing electric connection between unit 18 and electrodes 38. This embodiment allows discarding electrode assembly 14 after use while recycling handpiece 26.

[0071] Shown in FIG.8 is a preferred use of the present invention. A tissue penetrating instrument 12 is shown in operating condition during a vitrectomy procedure in an eye 122. A trocar and canula system are inserted in eye 122 across the conjunctival membrane layer 78 and the scleral tissue layer 70 into a vitreous cavity 126 creating sclerotomy 134 forming tissue opening 130. Canula 138 has a head 142 and a tube 146 shown inserted to its full extent of about 7 mm with head 142 lying over conjunctival membrane layer 78. Conjunctival membrane layer 78 is the superficial tissue layer 67 with a thickness of 0.393 ± 0.067 mm and scleral tissue layer 70 is the second tissue layer 68 with a thickness 0.43 ± 0.14 mm.

[0072] FIG. 9 illustrates canula 138 from FIG.8 lifted about 4 mm from the sclerotomy site 134 to maintain the distal portion of tube 146 inserted across tissue opening 38 to create space under cannula head 142 to position, align and insert electrode assembly 14 across tissue layer 78 into tissue layer 70.

[0073] FIG.10 and FIG.11 show front and side views of electrode assembly 14 with electrode base 82 placed flat between head 142 and superficial tissue layer 67 in the space produced after partial lifting of canula 138 as shown in FIG.9. Slot 98 admits tube 146 in a way that electrode base 82 can slide into a position aligned with tissue opening 130 at the point of contact between tube 146 and the closed round end of open slot 98.

[0074] FIG.12 is a side view from FiG.11 showing electrode assembly 14 after using a force parallel to the axis of tube 146 toward first and second tissue layers 67 and 68 of eye 122. Tissue penetrating electrodes 38 perforate the conjunctival membrane layer 78 and penetrate scleral tissue layer 70 aligned with the axis of tissue opening 130 and canula 138. FIG.13 is a detailed view from FIG.12 showing electrode assembly 14 positioned ready for activation prior to removal of canula 138 used for alignment and centration.

[0075] FIG.14 is a side view of electrode assembly 14 positioned ready for bipolar energy activation after removal of canula 138 previously used for alignment and centration.

[0076] FIG.15 and FIG.16 are a top view and a detailed top view of the electrode assembly 14 from FIG.14 showing electrodes 38 from electrode array 42 symmetrically disposed around tissue opening 130.

[0077] FIG.17A and FIG.17B are a front view and a detailed front view of the electrode assembly 14 from FIG.16 to further illustrate tissue penetration of electrodes 38 around tissue opening 130.

[0078] FIG.18A is a top view of electrode assembly 14. FIG.18B is a lateral sectional view along axis B-B in FIG.18A showing electrode assembly 14 including electrode base 82 holding electrode array 42 composed by electrodes 38. Electrodes 38 are fixated at the top portion of electrode base 82 leaving space 162 for electrodes 38 to bend sideways toward each other and toward tissue opening 38 when tissue layers contract by bipolar energy activation of electrodes 38.

[0079] FIG.19 is a lateral cross-sectional view of electrode assembly 14 shown after a force enough has been applied over assembly 14 by an operator to make electrodes 38 penetrate tissue layers 67 and 68. Electrodes 38 are seen piercing through tissue layer 67 and inserted into tissue layer 68 ready for bipolar energy activation. Tissue opening 130 is at the center of electrode array 42 between electrodes 38. Electrodes 38 can be rigidly fixated at the upper portion 150 of electrode base 82. Electrodes 38 can flex sideways inside the confined space 162 in the lower portion 154 of electrode base 82. The outer portion 158 of electrode base 82 surrounding space 162 determines the exposed length of electrodes 38 allowed to penetrate the tissue layers by providing an electrode 38 penetration limiting surface 166. Contact of penetration limiting surface 166 with superficial tissue layer 67 sets the deepness of electrode 38 penetration.

[0080] FIG.20 shows electrode assembly 14 and tissue layers 67 and 68 after completing a bipolar energy activation of electrodes 38 in electrode array 42. Tissue opening 130 disappears by tissue layer 68 contraction caused by bipolar energy activation of electrodes 38. Electrodes 38 are seen centripetally bent dragged by their distal ends 94 following the tissue layer 68 horizontal contraction that closed the tissue opening 130. Space 162 allows distal ends of electrodes 38 to bend and translate following tissue layer contraction.

[0081] FIG.21 A shows a side view of a pair of contiguous electrodes 38 from FIG.19 and FIG.20 ready for bipolar energy activation. The proximal ends of electrodes 38 are fixed to electrode base 82 and aligned in parallel. The distal portion of electrodes 38 is exposed to penetrate tissue layers and measures 0.7 mm with a sharp point and conductive surface seen deeply penetrating tissue layer 68. An electrically insulated surface 74 of the exposed region of electrode 38 is seen piercing through superficial tissue layer 67.

[0082] FIG.21 B shows the pair of contiguous electrodes 38 from FIG.21 A after bipolar energy activation while still inserted in the tissue layers. Distal ends 94 of neighbor electrodes 38 are shown approximating toward each other by bending of each electrode along its longitudinal axis. The approximation of neighbor electrodes is produced by tissue layer contraction after bipolar energy activation of electrodes 38 reducing the distance between electrode tissue penetration sites. The electrically insulated surface 74 of the exposed portion of electrodes 38 prevents direct delivery of bipolar energy to the superficial tissue layer 67.

[0083] FIG.22 shows an alternative embodiment of electrode assembly 14 incorporating a plurality of tissue layer compressing pillars 178 originating from the bottom surface 110 of electrode base 82 surrounding electrodes 38. Pillars 178 focalize the compressive force applied by the operator through shank 28 into a small area of the superficial tissue layer 67 around electrodes 38 penetration points reducing layer 67 thickness by tissue fluid centrifugal displacement and facilitating deep penetration of electrodes 38 into tissue layer 68.

[0084] FIG.23 shows another alternative embodiment with an electrode base 82 divided into a top fixed portion 182 where electrodes 38 are attached, and a bottom slidable shield portion 192 configured to protect electrodes 38 distal end 94 from being exposed before insertion. Gap 196 is the space that separates fixed portion 182 from slidable shield portion 192.

[0085] FIG.24 shows slidable shield portion 192 displaced by an operator’s force toward fixed portion 182 eliminating gap 196 and exposing the distal end 94 of electrodes 38 a fixed length suitable for system 10 operation.

[0086] FIG.25A and FIG.25B are front and side views of the embodiment shown in FIG.23 and FIG.24 showing slidable shield portion 192 in a first position with electrodes 38 protected. Shield safety locks 194 are shown in a position that prevents displacement of shield portion from this first position.

[0087] FIG.26A and FIG.26B are front and side views of the embodiment shown in FIG.23 and FIG.24 showing slidable shield 192 in a second position with electrodes 38 exposed ready for activation. After removal of shield safety locks 194 to allow sliding of shield 192 from the first position into the second position, shield 192 remains in the first position by the action of mild frictional forces between slidable shield 192 and fixed portion 182. A pair of latches 208 engage shield 192 with fixed portion 182 to prevent separation of both portions. Latch 208 also provides an intermediate convex protrusion 209 to provide a resistance to spontaneous displacement of shield 192 toward fixed portion 182 until a force is applied through shank 28 by an operator. retain shield 192 in the first position after removal of locks 194 until an operator pushes assembly 14 toward eye 122.

[0088] A set of alignment rods 202 are disposed in fixed portion 182. Alignment rods 202 can linearly displace inside alignment hollow cylinders 206 from slidable shield portion 192 when an operator applies pressure over electrode base 82 toward eye 122 through shank 28. This force linearly displaces shield 192 from the first position to the second position simultaneously exposing and inserting all electrodes 38 through tissue layer 67 into tissue layer 68.

[0089] FIG.27A shows an embodiment incorporating an adjustment screw 210 in fixed portion 182 from electrode base 82 to limit the travel distance of slidable portion 192 toward fixed portion 182 during insertion into tissue layers.

[0090] As shown in FIG.27B adjustment screw 210 can act as a travel limiter for slidable portion 192 and can be used to regulate the length of electrodes 38 distal end 94 in array 42 that can be exposed to penetrate tissue layers.

[0091] FIG.27C shows adjustment screw 210 in a totally retracted position allowing slidable shield 192 to travel the complete range toward fixed portion 182 producing the maximum exposure of the distal ends 94 of electrodes 38 in array 42 that can penetrate tissue layers.

[0092] FIG.28 shows a lateral view of an electrode assembly 14 ready for bipolar energy activation. Electrodes 38 are seen piercing through tissue layer 67 and inserted into tissue layer 68. Electrically insulated surface 74 at the proximal portion of electrodes 38 prevents direct delivery of bipolar energy into tissue layer 67. Pillars 178 concentrate the applied force used to insert electrode assembly 14 into tissue layers around electrodes 38. The localized pressure created by pillars 178 surrounding electrodes 38 is functional to reduce the thickness of tissue layer 67 by displacing tissue fluids sideways from tissue layer 67 electrode piercing points. In this way, pillars 178 cooperate to reduce thickness variability of tissue layer 67 making electrode penetration depth into tissue layer 68 more predictable.

[0093] Shown in FIG. 29 is an electro-surgical conditioning unit 214 for use in the present invention. Electro-surgical conditioning unit 214 can receive a standard bipolar electro- surgical energy signal from an external electro-surgical energy generator and further process it for use with an electrode assembly 14 of the present invention by allowing an operator to deliver bipolar energy following a pattern of electrodes activation, a pulse duration and a total number of activation loops though electrodes 38 in electrode array 42. The external electro-surgical energy generator can be a stand-alone unit or can be integrated into a surgical console such as a vitrectomy console. OPERATION OF THE INVENTION:

[0094] An electro-surgical system 10 and method of use is presented. Principle of operation relies on direct delivery of bipolar coagulation energy produced by an electro-surgical unit 18 through a plurality of tissue penetrating electrodes 38 into a tissue layer 68.

[0095] One preferred application of this invention is for closure of a sclerotomy opening 130 in an eye 122 after removal of a vitrectomy canula 138 during a vitrectomy procedure. A typical sclerotomy 134 opening 130 has two relevant tissue layers. Superficial tissue layer 67 corresponds to the conjunctival membrane layer 78 typically including Tenon’s layer which is thin and elastic. A second tissue layer 68 corresponds to the scleral tissue layer 70 which is thick and inelastic.

[0096] The invention operates based on a localized application of bipolar coagulation energy directly into the scleral tissue layer 70 through an array 42 of tissue penetrating electrodes 38 typically disposed around the sclerotomy 134 opening 130 to produce a contraction of the scleral tissue layer 70 near electrodes 38 to produce an effective closure of sclerotomy 134 opening 130.

[0097] An electro-surgical unit 18 can deliver direct bipolar coagulation energy into a scleral tissue layer 70 through a plurality of tissue penetrating electrodes 38 disposed in an electrode assembly 14 following an electrode array 42. An operator can define a bipolar coagulation power level using a power knob 19 in bipolar power subsystem 56 from unit 18 to produce a desired tissue contraction effect.

[0098] The bipolar coagulation power can be delivered to all complementary bipolar electrodes 38 in a single step by activation of footswitch 22. Electrodes 38 activation can last for the complete duration of footswitch 22 activation. Alternatively, electrodes 38 activation can be adjusted using a pulse duration timer 16 to last a fixed amount of time for each footswitch 22 activation cycle.

[0099] Interval duration control 20 can be adjusted to select an idle period duration between sequential electrode activation pulses. The idle period between activation pulses adjusted using control 20 can operate for sequential electrode activations of individual electrode groups and also between activation pulses applied to different electrode groups in electrode array 42. Use of pulse duration control 16 in combination with interval duration control 20 allows an operator to deliver a sequence of bipolar power activation periods separated by idle periods to produce a PWM effect for single electrode groups and also for sequential activation of electrode groups.

[0100] For electrode arrays 42 including any even number of electrodes 38, all complementary electrodes can be activated simultaneously. Shown in FIG.29 is an array 42 of electrodes 38 composed by 4 electrodes A, B, C and D. Electrodes A and C can receive pole-1 and electrodes B and D can receive pole-2 from bipolar power generator 46. In this modality all electrodes 38 receive a bipolar power signal that is complementary to each neighboring electrode producing a simultaneous bipolar coagulation effect between all electrodes A, B, C and D.

[0101] For electrode arrays 42 that include any number of electrodes greater than 2, one or more groups of electrodes 38 in array 42 can be energized following an activation sequence controlled by microcontroller 50. In this way delivery of excessive peak energy into tissue layers is avoided. An operator can select a pattern for the activation sequence of the electrode groups in an electrode array 42 using pattern control knob 15 at sequencer subsystem 58. For example, electrodes A-B can first receive opposing bipolar power signals pole-1 and pole-2, then electrodes B-C, then electrodes C-D and then electrodes D-A, following a circular pattern of activation around the sclerotomy port tissue opening 130 and producing a sequential bipolar coagulation effect.

[0102] Alternatively, an operator can select a different pattern of activation at sequencer 58, for example electrodes A-B can first receive an opposite bipolar signal, then electrodes C- D, then electrodes B-C and then electrodes D-A, following an activation pattern of opposing groups of electrodes 38 surrounding the sclerotomy port tissue opening 130. Interval duration control 20 can be used to select a desired idle period between each electrode 38 activation pulse.

[0103] Another alternative can be the simultaneous activation of more than one pair of electrodes in a sequence. For example, electrodes A-B and C-D can first receive opposing bipolar power signals pole-1 and pole-2, and then electrodes B-C and D-A. A similar logic can apply when the number of electrodes 38 forming an electrode array 42 is odd. For example, for an array 42 consisting of 3 electrodes A, B and C, the activation pulses can first be directed to electrodes A-B, then to electrodes B-C and then to electrodes C-A.

[0104] Many other patterns of activation are also possible without departing from the scope of the present invention. For example, bipolar power signal pole-1 can be applied to electrodes A and C while bipolar power signal pole-2 is only applied to electrode B. Then electrodes B and A can receive bipolar power signal pole-1 while bipolar power signal pole-2 is only applied to electrode C. Then electrodes C and B can receive bipolar power signal pole-1 while bipolar power signal pole-2 is only applied to electrode A. In this way an electrode group can be composed by a different number of electrodes receiving bipolar power signal pole-1 and bipolar power signal pole-2.

[0105] A single activation pulse can be applied to an electrode group. Also, a plurality of activation pulses separated by an idle interval can be applied to each electrode group before moving into activation of a different electrode group. The operator can determine the number of complete electrode activation sequences to deliver using loop number control 17. The total amount of bipolar energy delivered into tissue layers can be computed using the bipolar power setting, the PWM ratio and the total electrode activation time. Parameter settings for controls 15, 16, 17, 19 and 20 can be adjusted according to the operator’s experience, results, and tissue characteristics. Sequencer delivery of energy can last for a fixed amount initiated for example by an activation command using footswitch 22 or continuously until footswitch 22 is released. Electrode groups can be activated only once or repeatedly in a loop for each activation command. The set of selected parameters can be displayed at display 24. The selected electrode activation pattern can be graphically displayed and animated using display 24 in a way that is comprehensive for an operator.

[0106] An operator can also select a continuous mode setting at loop number control 17 to have sequencer subsystem 58 to remain active during the full duration of activation of footswitch 22. In this way an operator can visually monitor the status of closure of tissue opening 130 releasing footswitch 22 after closure completion.

[0107] Other forms of activation of electro-surgical unit 18 are possible without departing from the scope of the present invention. For example, electro-surgical unit 18 can by activated by a voice command. Power delivery from electro-surgical unit 18 can also be automatically activated by an imaging system including an image processing algorithm that detects correct positioning of electrode assembly 14 and cuts power delivery off once the imaging system and image processing algorithm detects that tissue opening 130 has been closed satisfactorily.

[0108] A method of use of electro-surgical system 10 of the present invention consists in first having an operator select preferred settings using controls 19, 15, 16, 17, 20 from electro-surgical unit 18, aligning a tissue penetrating electrode assembly 14 over a tissue opening 130, compressing electrode assembly 14 with electrodes 38 disposed following array 42 against the tissue layers 78 and 70 surrounding opening 130 in a way that electrodes 38 penetrate to a selected depth the tissue layers, activating the bipolar coagulation unit 18 using footswitch 22 to deliver bipolar coagulation energy to electrodes 38 disposed forming an array 42 to contract tissue layer 70 until tissue layer opening 130 is satisfactorily closed.

[0109] Positioning and alignment of electrode assembly 14 over opening 130 by an operator can be based on direct visualization of opening 130 after complete removal of the tissue penetrating instrument 12. Alternatively, alignment can be performed before removal of instrument 12 from opening 130 by positioning of assembly 14 guided by alignment slot 98 in a way that electrode assembly 14 is positioned in stable manner over opening 130 in an aligned position.

[0110] Electrode assembly 14 can then be displaced toward the tissue layers using tissue penetrating instrument 12 shaft as a guide using a force sufficient to make the electrode array 42 penetrate the target tissue layer 68. Once electrode assembly 14 has penetrated tissue layer 68 to the full extent of the exposed length of electrodes 38 then instrument 12 previously used as a guide can be totally removed. Bipolar coagulation energy can then be applied to electrode array 42 until opening 130 is satisfactorily closed by activation of footswitch 22.

[0111] In a preferred embodiment, electrode assembly 14 has electrodes 38 disposed in a way to provide freedom to flex laterally and centripetally to follow horizontal displacements of the tissue penetration site due to tissue contraction between electrodes during bipolar energy activation. In this way, electrode flexibility facilitates tissue contraction instead of opposing tissue displacement, as could be the case with laterally restrained electrodes.

[0112] In another embodiment, an electrode shield 192 can prevent electrodes from contacting tissue layers during the alignment process. Only when the operator displaces the electrode assembly 14 and applies pressure toward the tissue layers do the electrodes become exposed and penetrate the tissue layers at the desired depth.

Claims

CLAIMS1. An electro-surgical system for closing a tissue opening that remains in tissue layers after removal of a tissue-penetrating instrument, the electro-surgical system comprising: an electrode assembly including a plurality of tissue-penetrating electrodes distributed in an electrode array configured for insertion into the tissue layers near the tissue opening, an alignment feature coupled to the electrode assembly and configured to receive or align with at least a portion of the tissue-penetrating instrument such that the electrode array can be positioned with respect to the tissue opening before the tissue-penetrating instrument is removed, and an energy source operable to deliver bipolar electro-surgical energy to the plurality of tissue-penetrating electrodes for effecting tissue closure of the tissue opening.

2. The electro-surgical system of claim 1 , wherein the alignment feature comprises a channel, sleeve, or guide aperture sized and shaped to engage or align with the distal shaft of the tissue-penetrating instrument to ensure precise positioning of the electrode array.

3. The electro-surgical system of claim 1 , wherein one or more of the tissuepenetrating electrodes include regions of electrically insulated surface configured to prevent delivery of bipolar electro-surgical energy to selected portions of the tissue layers.

4. The electro-surgical system of claim 3, wherein the electrically insulated surface regions are made from a polymeric insulator, ceramic coating, or other dielectric material that is bonded to each electrode.

5. The electro-surgical system of claim 1 , wherein the energy source is configured to deliver bipolar electro-surgical energy to the plurality of tissue-penetrating electrodes simultaneously.

6. The electro-surgical system of claim 1 , wherein the energy source is configured to deliver bipolar electro-surgical energy sequentially to selected groups of tissuepenetrating electrodes following a predetermined electrode activation pattern.

7. The electro-surgical system of claim 6, wherein the predetermined activation pattern is selected based on a parameter of the tissue opening, including size, shape, or tissue type, to optimize tissue closure.

8. The electro-surgical system of claim 1 , wherein the electrode array is dimensioned to be used in microsurgical procedures, including sclerotomy closure in a vitrectomy procedure.

9. The electro-surgical system of claim 1 , further comprising a control unit operatively coupled to the energy source, the control unit being configured to regulate one or more operational parameters of the bipolar electro-surgical energy, including voltage, current, or waveform shape, based on the tissue characteristics encountered by the electrode array.

10. The electro-surgical system of claim 1 , wherein the electrode assembly is detachably coupled to the alignment feature, enabling replacement of the electrode assembly with an alternative electrode assembly having different electrode spacing or lengths suitable for varying tissue depths.

11. The electro-surgical system of claim 1 , further comprising one or more sensors configured to detect tissue parameters, wherein the system adjusts the bipolar electro-surgical energy based on real-time feedback from the one or more sensors to optimize tissue closure.

12. The electro-surgical system of claim 1 , wherein the electrode assembly comprises a rigid support or base that maintains the spacing between the plurality of tissue-penetrating electrodes for consistent tissue engagement around the tissue opening.

13. The electro-surgical system of claim 1 , wherein at least one of the tissuepenetrating electrodes further comprises a sharp or pointed distal tip, facilitating the insertion of the electrode array into the tissue layers surrounding the tissue opening.

14. A method for closing a tissue opening remaining in tissue layers after removal of a tissue-penetrating instrument, the method comprising:(a) providing an electrode assembly comprising a plurality of tissue-penetrating electrodes distributed in an electrode array and an alignment feature configured to receive or align with at least a portion of the tissue-penetrating instrument;(b) positioning the electrode assembly with respect to the tissue opening by using the alignment feature to guide the electrode array into the tissue layers adjacent to the tissue opening;(c) removing the tissue-penetrating instrument from the tissue layers while maintaining the electrode assembly in position near the tissue opening; and(d) delivering bipolar electro-surgical energy via at least one subset of the plurality of tissue-penetrating electrodes to close the tissue opening.

15. The method of claim 14, further comprising, before step (c), partially withdrawing the tissue-penetrating instrument to confirm alignment of the electrode array with the tissue opening, and then fully removing the tissue-penetrating instrument while keeping the electrode assembly in place.

16. The method of claim 14, wherein delivering bipolar electro-surgical energy in step (d) comprises simultaneously energizing all of the tissue-penetrating electrodes of the electrode array.

17. The method of claim 14, wherein delivering bipolar electro-surgical energy in step (d) comprises sequentially energizing selected groups of tissue-penetrating electrodes following a predetermined electrode activation pattern.

18. The method of claim 17, further comprising selecting the predetermined electrode activation pattern based on one or more parameters of the tissue opening, including tissue type, thickness, or shape.

19. The method of claim 14, further comprising covering selected surface regions of at least one tissue-penetrating electrode with an electrical insulator prior to step (b), such that the insulated regions do not deliver bipolar electro-surgical energy to surrounding tissue.

20. The method of claim 19, wherein the electrical insulator is selected from a polymeric coating, a ceramic coating, or another dielectric material bonded to the surface of the electrode.

21. The method of claim 14, further comprising monitoring one or more tissue parameters during delivery of bipolar electro-surgical energy, and adjusting at least one energy parameter based on the monitored tissue parameters.

22. The method of claim 14, wherein the method is used during a microsurgical procedure involving minute punctures, including a sclerotomy performed in a vitrectomy procedure, and the electrode array is dimensioned to penetrate the ocular tissue layers.

23. The method of claim 14, further comprising detaching and removing the electrode assembly from the tissue layers after the tissue opening is closed, leaving closed tissue layers substantially free of fluid leakage.

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