Abstract:
A laser tissue fusion device is optimized for particular surgical applications to join tissue layers. The device has two opposed arms that engage and disengage to clamp and release layers of tissue therebetween. The distal end of the first arm is disposed opposite the distal end of the second arm. A laser energy source generates therapeutic laser energy is either integrated within the device is a separate unit. An energy pathway transmits the laser energy to the distal end of the first arm to deliver the laser energy to tissue layers clamped between the distal ends of the arms. An actuator decreases the separation distance between the distal ends of the arms to clamp the tissue layers and activates the laser energy source upon engagement. The laser energy source delivers a burst of energy at a predetermined wavelength for a predetermined period of time sufficient to spot weld the tissue.

Description:
BACKGROUND 
       [0001]    Since the late 1980&#39;s, laboratory research has indicated the potential of using lasers to “weld” biological tissues together, sometimes facilitated by introducing an albumen solder. Many encouraging results have been obtained, suggesting that lasers hold promise for instant wound closure. An important advantage is achieving an instant, watertight bond. While some laser systems have been developed for use in surgical applications, none has been able to realize a practical system that offers a comparative advantage to standard procedures. This is due primarily to two factors: the systems have attempted to provide general applicability for multiple tissue types, i.e., a one-size-fits-all approach, and the systems require users to exercise a significant amount of experience and skill in detecting changes in tissue appearance while using the laser. In particular, it has been found that different tissues require different sets of laser parameters, e.g., wavelength, pulse duration, power level, exposure time, and pressure. An additional drawback is that, even with optimized performance parameters, use of these test systems is an “art,” requiring an inordinate amount of experience on the part of the operator, despite attempts to automate the feedback and control of the laser devices. Thus, it is easy to burn tissue or end up with an incomplete tissue weld. 
         [0002]    During surgical procedures to correct nasal septal deviation—nasal cavity blockage linked to chronic sinusitis and other conditions—bone and cartilage are removed from the centerline of the nose, while preserving the mucoperichodrial flaps covering both sides. These flaps must be brought back together, a procedure called “coaptation.” This prevents blood clotting in-between and hematoma formation. Coaptation must be completed to ensure the survival of septal cartilage. If the flaps are not re-joined, the blood supply will be reduced, killing the remaining cartilage and causing serious, irreversible saddle nose deformity wherein a patient&#39;s nose collapses. 
         [0003]    Currently coaptation of the tissue membranes lining the septum is accomplished with a needle and suture, stapling, or by intranasal packing. The current suturing method comes with a number of serious shortcomings, including difficulty visualizing and guiding the needle deep in the nasal cavity when working through the nostrils, inadvertent tearing of the vascular nasal wall by the needle (with resultant bleeding leading to immediate visualization problems and to later scarring and healing problems through the development of nasal synechia), and the possibility of breaking or detaching the needle (requiring a radiological scan to ensure removal of all fragments). Stapling can similarly cause bleeding problems with similar side effects. Both suturing and stapling can result in sub-optimal coaptation due to a lack of uniformity in closure. This current suture coaptation method also consumes a relatively long time in the operating room. 
         [0004]    The other method currently used, i.e., inserting intranasal packing, is not a benign procedure. In addition to causing discomfort for patients (the material is left in the nose for 24 to 72 hours), studies show that the intranasal packing reduces oxygen saturation and can lead to toxic shock syndrome. In addition to packing, flat splints are often placed in the nostrils on each side of the septal wall to prevent fibrous growth that could potentially cause nasal synechia as a result of a needle tearing and pushing or pulling mucosa cells into the nasal cavity during suturing. 
         [0005]    Repairing and grafting nerves and blood vessels using a microscope present many difficulties for traditional surgical closure techniques, e.g., sutures, staples, and clips. The small size of the tissues involved necessitate specialized thread and needles. For conventional procedures, suture with a diameter on the order of 0.1 mm is common. Microsurgical procedures can require suture two orders of magnitude smaller, down to 0.001 mm. Surgeons must train extensively to compensate for hand tremor, which is significant given the small structures to be joined. 
         [0006]    The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention is to be bound. 
       SUMMARY 
       [0007]    A laser tissue fusion device joins layers of tissue in surgical procedures. The laser septal closure device overcomes the problems described above by optimizing the performance and simplifying use through dedication to single applications. Because the laser tissue fusion device is optimized for particular surgical applications for joining tissue layers, the device thus overcomes the barriers that have prevented others from creating an economically viable laser fusion solution. The laser tissue fusion device may be pre-set to the optimal performance characteristics for the particular tissue involved and packaged in an easy to use device. The joining of tissue layers is accomplished through the controlled application of laser heating and pressure to induce protein denaturation and subsequent tissue fusion, through renaturation and intertwining, across the interface between tissue layers. The device can be used to provide an immediate, water-tight closure to wet or dry wounds. This can facilitate accelerated healing. 
         [0008]    The laser tissue fusion device has two opposed arms that may be engaged and disengaged to clamp and release layers of tissue therebetween. The distal end of the first arm is disposed opposite the distal end of the second arm. A laser energy source that generates therapeutic laser energy is provided either integrated within the body of the device or as a separate unit connected to at least one of the arms. An energy pathway transmits the therapeutic laser energy from the laser energy source to the distal end of the first arm to deliver the therapeutic laser energy to tissue layers clamped between the distal ends of the arms. The energy pathway may be in the form of an optical fiber. An actuator is configured to decrease the separation distance between the distal end of the first arm and the distal end of the second arm upon engagement and thereby clamp the tissue layers between the distal ends of the arms. The actuator is further configured to activate the laser energy source when the tissue layers are clamped between the arms. Pressure between the arms is governed by the actuator mechanism, which is limited to prevent excess clamping force on the tissue. The laser energy source further delivers a burst of energy at a predetermined wavelength for a predetermined period of time sufficient to spot-weld the portion of tissue between the ends of the arms. The distal end of the first arm may have an angled mirror and/or a lens to direct and focus the laser energy from the energy pathway into the tissue. The distal end of the second arm may be mirrored to reflect any laser energy passing through the tissue back into the tissue. 
         [0009]    In one implementation, a laser tissue fusion device is optimized for surgical procedures involving the nasal septum (the internal, mid-line of the nose), namely coaptation of mucoperichondrial membranes (septal mucosa). The laser tissue fusion device is a superior alternative to the current method of coaptation using suture. The device eliminates the shortcomings described above by permitting a surgeon to quickly, and with one hand, “spot weld” the mucoperichondrial flaps. Each of the arms of the laser fusion device is configured to fit within respective nostrils of the patient and engage the septal mucosa. The laser tissue fusion device provides several benefits for both patients and doctors including improved visualization, no tearing of the lateral nasal wall and subsequent development of synechia, no broken needles, and reduced surgical time. The device may also find application in rhinoplasty where nasal cartilage is harvested for reconstructive purposes, and surgeries requiring access to the base of the skull employing a transsphenoidal approach, i.e., moving the septum, such as to access the pituitary. 
         [0010]    In another implementation, a laser tissue fusion device is optimized for endoscopic surgical procedures. The arms of the device may be mounted at the distal end of a tube, trochar, or other endoscopic device. A handle at the proximal end may have an actuator to manipulate the second arm to clamp or unclamp layers of tissue between the arms. The actuator is further configured to activate the laser energy source when the tissue layers are clamped between the arms. The device permits a surgeon to quickly, and with one hand, “spot weld” the layers or flaps of tissue within the surgical field. For example, the endoscopic device may be useful in colorectal and gastric bypass surgeries for fusing tissue folded against itself. 
         [0011]    In another implementation, small laser tissue fusion devices may be optimized for use in microsurgical applications. Laser fusion devices provide a huge benefit since there is no relative motion required during joining as is needed between the tissue and a needle/suture. The surgeon can ensure proper positioning of the tissue layers before actuating a spot-welding laser, which has integrated tissue-holding arms or fixtures to approximate the tissue to be joined. 
         [0012]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other features, details, utilities, and advantages of the present invention will be apparent from the following more particular written description of various embodiments of the invention as further illustrated in the accompanying drawings and defined in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is an isometric view of an exemplary embodiment of a laser tissue fusion device designed principally for fusion of septal tissue. 
           [0014]      FIG. 2  is an isometric view of the laser tissue fusion device of  FIG. 1  with the arms of the device in place for use during nasal surgery. 
           [0015]      FIG. 3  is a cross section of a detail of the distal tips of the arms of the laser tissue fusion device of  FIG. 1  in an actuated state. 
           [0016]      FIG. 4  is a schematic view of an exemplary embodiment of a disposable hand-held laser tissue fusion device connected to a reusable laser energy source by a fiber optic cable. 
           [0017]      FIG. 5  is an isometric view in cross section of an alternative embodiment of a laser tissue fusion device with a laser energy source within the handle. 
           [0018]      FIG. 6  is an isometric view of the laser tissue fusion device of  FIG. 1  in a pre-actuated state. 
           [0019]      FIG. 7  is a side elevation view of a detail of the arms of the laser tissue fusion device in the pre-actuated state of  FIG. 5  with layers of tissue positioned between the arms. 
           [0020]      FIG. 8  is an isometric view of the laser tissue fusion device of  FIG. 1  in an actuated state. 
           [0021]      FIG. 9  is a side elevation view of a detail of the arms of the laser tissue fusion device in the actuated state of  FIG. 7  with layers of tissue clamped between the arms. 
           [0022]      FIG. 10  is an isometric view in cross section of the laser tissue fusion device of  FIG. 1  in a pre-actuated state. 
           [0023]      FIG. 11  is an isometric view in cross section of the laser tissue fusion device of  FIG. 1  in an actuated state. 
           [0024]      FIG. 12  is an isometric view of an implementation of a endoscopic laser tissue fusion device. 
           [0025]      FIG. 13  is an elevation view in cross section of a detail of the distal tip of the endoscopic laser tissue fusion device of  FIG. 12  in an open, pre-actuated state. 
       
    
    
     DETAILED DESCRIPTION 
     Septal Fusion Implementations 
       [0026]    A laser tissue fusion device according to the implementations described in further detail below may be used to “spot weld” layers of tissue together. A primary application of one implementation of the laser tissue fusion device may be in septoplasty operations. These are common surgical procedures which correct nasal septal deviation—nasal cavity blockage linked to chronic sinusitis and other conditions. Bone and cartilage are removed from the centerline of the nose, while preserving the mucoperichodrial flaps covering both sides. The flaps must be brought back together, “coapted,” to prevent blood clotting in between (i.e., hematoma formation). If the flaps are not re-joined, the blood supply will be reduced, killing the remaining cartilage and causing serious, irreversible saddle nose deformity wherein a patient&#39;s nose collapses. This implementation of a laser tissue fusion device may also find application in rhinoplasty where nasal cartilage is harvested for reconstructive purposes. This implementation of the laser tissue fusion device may further be used during surgeries requiring access to the base of the skull employing a transsphenoidal approach, i.e., moving the septum, such as to access the pituitary. 
         [0027]      FIG. 1  depicts an exemplary implementation of a handheld laser tissue fusion device  100  designed principally for nasal operations. The device  100  may have a housing  101  in the form of a handle which supports a mechanical actuator such as a trigger  102 . The trigger  102  may be shielded from inadvertent actuation by a trigger guard  103  formed as part of the handle housing  101 . The housing  101  and the trigger  102  may be formed of molded plastics or other polymers to provide a desirable ergonomic feel for the clinician. 
         [0028]    The device  100  further includes a motile arm  104  and a static arm  105 . In this embodiment, the static arm includes a laser energy output  106  and houses a pathway (not shown) for delivering the laser energy from a laser energy source to the output  106 . The arms extend distally from the handle  102  and may be oriented generally parallel with each other. The arms  104 ,  105  are substantially the same length and extend substantially the same distance from the handle  101  to their distal ends  107 . The separation distance between the distal ends  107  of the arms  104 ,  105  may be selected to conform to a typical spacing between the nostrils of a patient to allow the distal ends  107  of the arms  104 ,  105  to be easily inserted into the nostrils. In some embodiments the spacing between the arms  104 ,  105  may be adjustable and, in other embodiments, different handle configurations may be designed to provide a range of spacing between the distal ends  107  of the arms  104 ,  105 . A visual indicator, for example a light emitting diode  122  (LED) may be mounted on the handle  101  to indicate when laser energy is being output from the device  100 . Alternative indicators could be used, for example an audible signal could be generated. 
         [0029]      FIG. 2  depicts a laser tissue fusion device  100  in use in the treatment of a patient  108  for septal closure. The distal ends of each of the arms  104 ,  105  are inserted within respective nostrils of the patient  108  to reach opposing positions on each side of the septal mucosa. 
         [0030]      FIG. 3  depicts a manner by which the laser energy  121  leaves the device  100  to act upon the tissue. A fiber optic cable  127 , composed of one or more small strands, carries the laser energy  121  from the laser energy source, e.g., a laser diode contained within the handle or a laser source located in a stand-alone unit. The fiber optic cable  127  is mounted in the static arm  105 . A reflector  128  is positioned near an aperture of the fiber optic cable  127  and directs the emanating beam of laser energy  121  toward the tissue lying between the two arms  104 ,  105 . In one embodiment, a lens (not shown) may be introduced between the aperture  130  and the reflector  128  or between the reflector  128  and the tissue to focus the laser energy  121 . A reflective surface  124  is formed on the distal end of the motile arm  104  aligned with the path of the laser energy  121  redirected by the reflector  128 . The reflective surface  124  acts to prevent any laser energy  121  that penetrates the tissue entirely from irradiating undesired tissue locations by reflecting the laser energy  121  back to the same tissue location receiving the incident laser energy. 
         [0031]      FIG. 4  depicts one implementation of laser tissue fusion system  109  with a handheld tissue fusion device  100  and a separate, reusable laser energy source  110 . The laser energy source  110  is connected to the device  100  by an umbilical  111 . The umbilical  111  may be composed of a fiber optic cable for transmitting the laser energy from the laser energy source  110  and one or more electrical wires for the control of the laser energy source  110 . A control system in the laser energy source is actuated by signals in the electrical wires upon actuation of the trigger  102  and controls the power and duration of the laser energy output from the laser diode  118  at a level and for a period optimized to fuse the tissue layers. The laser energy is transmitted from the laser energy source  110  via the umbilical  111 , which connects with the fiber optic cable (see  FIG. 3 ) in the handle  101  and travels through the static arm  105  to the laser output at the distal end  107 . The LED  122  provides a visual indication during the application of the laser energy and is deactivated after the duration of energy application is complete to indicate to the clinician that the fusion is complete and that the device  100  may be disengaged from a clamped position for relocation to fuse another area of tissue or that the device  100  may be removed. 
         [0032]      FIG. 5  depicts a compact implementation of a laser tissue fusion device  112  in a cross-section view wherein one side of the handle  113  is shown. As in implementations previously described, the handle  113  of the device  112  forms a trigger guard  114  to shield a trigger  120  or actuator. A static arm  115  and a motile arm (not shown) each extend parallel distally from the handle  113  to a distal end  117  where the laser energy is output from the static arm  115 . In this embodiment, the handle  113  may be reusable while the static arm  115  and the motile arm (not shown) may be disposable or reusable after sterilization. As shown in  FIG. 5 , the static arm  115  is held at its proximal end within a receptacle  116  in the handle  113  and may be removed therefrom and replaced. The motile arm (not shown) is similarly held in a receptacle from which it can be removed and replaced. 
         [0033]    The laser energy source in this embodiment may be generated by a laser diode  118  housed within the handle  113  and powered by a replaceable or rechargeable power source, e.g., a battery (not shown). Laser power generation is initiated by actuation of a switch  144  by the motion of the trigger  120 . A control system (not shown) controls the power and duration of the laser energy output from the laser diode  118  at a level and for a period optimized to fuse the tissue layers. Again, the LED  122  may provide a visual indication of the duration of the application of the laser energy. The therapeutic laser energy output from the laser diode  118  is directed to the distal end of the static arm  115  via an energy pathway  119  upon actuation of the trigger  120 . The energy pathway  119  may be formed inside the handle  113  by a series of mirrors or reflective surfaces that direct the laser energy within the handle  113  to be transmitted within the static arm  115  to the point of laser output at the distal end  117 . Alternatively, the energy pathway  119  may be a fiber optic cable. 
         [0034]    Laser energy sources of various wavelengths can be used, as many will impart a sufficient amount of useful photo-thermal energy to tissue. A number of wavelengths may be used, for example, 808 nm, 830 nm, 1060 nm, 1220 nm, 1430 nm, and 10.6 μm wavelengths. The size of the laser spot can likewise be varied. A nominal diameter on the order of 1 mm to 5 mm is appropriate for the coaptation of nasal mucosa. Success can be achieved for a range of beam power levels impinging on the tissue, in particular between 500 mW to 5 W works well. The dwell time needed to form a sufficient tissue to tissue bond is inversely related to the power density of the beam, which is a combination of the spot size and power, and is typically between 10 W/cm 2  and 100 W/cm 2 . Success can be achieved with various times, but between 1 sec and 10 sec has been found to work well in this application. The total energy deposited on the tissue varies with the chosen wavelength, and typically ranges from 50 J to 500 J. 
         [0035]      FIG. 6  depicts the device  100  in a disengaged position. The trigger  102  is not actuated, the arms  104 ,  105  are open and spaced apart, the LED indicator  122  is off, and there is no laser emission.  FIG. 7  shows the distal ends  107  of the arms  104 ,  105  straddling layers of tissue  123  to be joined. Comparatively,  FIG. 8  depicts the device  100  in an actuated or engaged position. The trigger  102  is depressed, the arms  104 ,  105  are closed, the LED indicator  122  is on, and laser energy is emitted at the distal end  107 .  FIG. 9  shows the distal ends of the arms  104 ,  105  pinching or clamping layers of tissue  123  to be joined with laser energy applied to the tissue between the distal ends  107  of the arms  104 ,  105 . 
         [0036]      FIG. 10  depicts the device  100  in cross section in a disengaged position to provide an example of a structure for motivating the motile arm  104  to deflect toward the static arm  105  (not shown) by rotating on a hinge connection  129  at a proximal end of the motile arm  104  housed within the handle  101 . In  FIG. 10 , the trigger  102  is not depressed and the arms  104 ,  105  are open at their maximum separation distance. As shown, the trigger  102  may be constructed with a wedge-shaped portion  125  that, when in the disengaged position, rests against a cam surface  145  of the motile arm  104  and holds the motile arm  104  against the inside wall of the housing  101 .  FIG. 10  also depicts an example of trigger actuation detection. A switch  126  is mounted inside of the housing  101  behind the trigger  103 . Since there is no contact between the trigger  102  and the switch  126 , the laser energy source is inactive. 
         [0037]    Comparatively,  FIG. 11  depicts the same embodiment of the device  100  in cross section as in  FIG. 10 , but in an actuated position. The trigger  102  is depressed against the force of a spring (not shown; positioned in the other half of the handle  101 ) and the arms  104 ,  105  (not shown) are closed, i.e., the separation distance between the distal ends  107  of the arms  104 ,  105  is reduced. When the trigger  102  is depressed, the wedge-shaped portion  125  moves behind the cam surface  145  and permits the movement of the motile arm  104  toward the static arm  105  about the hinge connection  129  under the action of a spring positioned between the housing  101  and the motile arm  104  (not visible). This causes the distal end  107  of the motile arm  104  to deflect laterally toward the distal end  107  of the static arm  105  (not shown), i.e., the distal end  107  of the motile arm  104  moves generally normal to its length. When the arms  104 ,  105  are positioned in either side of the nasal cavity, the deflection of the motile arm  104  holds the arms  104 ,  105  in close proximity to each other and against the septal tissue with a preset force. 
         [0038]    When the trigger  102  is depressed, it also makes contact with the switch  126  causing the laser energy source to turn on for a determined amount of time under the control of a timing circuit. The switch  126  is connected to the external laser energy source by the umbilical  111  (connection not shown; positioned in the other half of the handle  101 ). The laser then fires at a preset intensity for a preset duration according to the circuit after which the arms  104 ,  105  may be released by releasing the trigger  102 . When the trigger  102  is fully depressed, it may be detected by a contact sensor on the switch  126  that interfaces with the back of the trigger  102  when the trigger  102  is fully depressed. The switch  126  signals the circuit to fire the laser for a set time period that is visually indicated by the LED  122 . If the trigger  102  is released before the laser firing time period has ended, the lack of contact with the contact sensor on the switch  126  may be detected by the circuit, which may automatically shut off the laser as a safety measure. 
         [0039]    In an alternate implementation, the trigger mechanism may be designed to cause both arms to move and pinch together against the septal tissue. Such a configuration may be achieved, for example, by constructing the trigger with a pair of linear cams to interface with each of the arms. This embodiment may be desirable in order to ensure that equal pressure is applied to both sides of the septal wall. However, since the arm housing the laser pathway is no longer stationary, the angles of any reflective surfaces forming the pathway may have to be adjusted as appropriate to accommodate the angle of the arm. 
         [0040]    In another implementation, the distal ends of the arms may be pressed toward each other by a set of compression springs within the handle. The springs may be chosen to provide a desired force and move the distal ends of the arms toward each other to pinch the septal tissue together without physically damaging the tissue. The tissue may then be fused together with the laser energy. 
         [0041]    In a further implementation, movement of the arms may be electrically actuated upon pressing the trigger. For example, a solenoid in the handle may be actuated to cause the motile arm to move toward the static arm (or to cause both arms to move together). A timing circuit may be used to trigger the solenoid to return to its inactive position after a set period of time corresponding to clinical efficacy of the laser. The solenoid may further be adjusted to change its travel distance to increase or decrease the separation distance between the distal ends of the arms depending upon the particular thickness of the patient&#39;s septum. This thickness may be measured in advance of the procedure to allow adjustment of the solenoid to a proper setting. 
       Fusion Methodologies 
       [0042]    A method of performing coaptation of the mucoperichondrial flaps in nasal septal tissue may comprise the following operations. First, the septal tissue is pressed together from opposite sides accessed through the nostrils of a patient. This pressure may be applied by pulling the trigger and closing the arms of the laser fusion device. Next, therapeutic laser energy is applied to the septal tissue for a period of time sufficient to fuse the septal tissue. The laser energy is actuated upon actuation of the trigger, which simultaneously applies the pressure to the septal tissue. Once a therapeutic time has elapsed and the flaps have been welded together the laser energy ceases and the pressure on the septal tissue may be released. Depending upon the area of the flaps that require coaptation, this method may be repeated several times at different locations on the septal tissue to “spot weld” the tissue together. Generally, 6-8 spots of about 2 mm diameter are sufficient to hold the septal mucosa together and avoid the need for nasal packing. Additionally, the need for splints is removed because there is little possibility of creating nasal synechia within the nasal cavity as may occur when suturing. 
         [0043]    One reason this methodology is effective in the application to septal mucosa is that clinical studies have shown that human mucoperichodrial flaps are remarkably consistent in thickness (on the order of 1 mm each side or 2 mm total) across race, gender, and size of individual. Therefore, the thickness of the septal mucosa is not a significant variable to consider when determining the optimal power and application time to achieve fusion. Thus, a single set of therapeutic parameters can be set for the device to achieve optimal results for any individual with no need for experience or skill in laser fusion on the part of the clinician. 
         [0044]    This method of coapting mucoperichondrial flaps has been demonstrated in advance of clinical trials through benchtop experiments on representative tissue systems. These experiments are designed to the optimal combination of performance parameters, e.g., laser wavelength, duration of irradiation, laser power level, and mechanical pressure, to achieve tissue fusion. A benchtop testing device provides controlled tests on representative tissue models. The model membranes (i.e., possessing similar material properties to the collagen-rich lamina propria and periosteum, which underlie the mostly squamous epithelial cells of the mucoperichondrial flaps) employed in initial testing may include AlloDerm®. AlloDerm® is commercially available, donated human tissue that has been processed to remove all epidermal and dermal cells, while preserving the remaining biological dermal matrix. Additionally, laser fusion on harvested horse septal mucosa has been performed successfully. 
         [0045]    A membrane support table may be used to hold layers of tissue in proximity to one another and positioned between the jaws of the benchtop testing device. Compression induced between the jaws in tissue membranes may be controlled with a rack and pinion plunger and measured with a load cell. The membrane in the support table may be wetted as needed to more closely simulate in vivo conditions. The strength of the resulting tissue bonds may be analyzed in a mechanical pull test and under a microscope. Experimental results under a variety of conditions using horse mucosa is presented in the table below. 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
               
               
                   
                   
                 Arm 
                   
                   
                   
               
               
                 Wavelength 
                 Duration 
                 Force 
                 Power 
                 Fusion 
                 Visual 
               
               
                 (nm) 
                 (s) 
                 (lbs) 
                 (W) 
                 Effect 
                 Appearance 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 808 
                 5 
                 1.5 
                 1.7 
                 None 
                 No Discoloration 
               
               
                 808 
                 10 
                 1.5 
                 1.7 
                 None 
                 No Discoloration 
               
               
                 808 
                 10 
                 1.5 
                 3.2 
                 None 
                 No Discoloration 
               
               
                 808 
                 30 
                 0.5 
                 2.5 
                 Minimal 
                 Slight 
               
               
                   
                   
                   
                   
                   
                 Discoloration 
               
               
                 808 
                 60 
                 1 
                 2 
                 Minimal 
                 Slight 
               
               
                   
                   
                   
                   
                   
                 Discoloration 
               
               
                 808 
                 60 
                 0.5 
                 2.5 
                 Excellent 
                 Slight 
               
               
                   
                   
                   
                   
                   
                 Discoloration 
               
               
                 808 
                 60 
                 0.5 
                 3 
                 Excellent 
                 Burned Tissue 
               
               
                 915 
                 30 
                 0.5 
                 2.4 
                 None 
                 No Discoloration 
               
               
                 915 
                 60 
                 0.5 
                 2.4 
                 None 
                 Slight 
               
               
                   
                   
                   
                   
                   
                 Discoloration 
               
               
                 1064 
                 30 
                 0.5 
                 2.5 
                 None 
                 No Discoloration 
               
               
                 1064 
                 66 
                 0.5 
                 2.5 
                 Minimal 
                 Slight 
               
               
                   
                   
                   
                   
                   
                 Discoloration 
               
               
                   
               
             
          
         
       
     
         [0046]    Three different wavelengths of laser light energy at different power levels were used in this exemplary experimental series. The duration of the laser energy application and the force holding the tissue layers together were also varied. In actual practice, the force applied to hold the tissue membranes together was insignificant as long as the membranes were in physical contact with each other at the weld spot. As indicated, laser energy applied to tissue layers at a wavelength of 808 nm, at 2.5 W of power, and for a period of 60 seconds produced the best results (i.e., excellent adhesion with minimal tissue necrosis) in this experimental series with horse mucosa. Additional combinations of wavelengths, power settings, and durations may provide good results as well. 
       Endoscopic Implementations 
       [0047]      FIG. 12  depicts an implementation of a laser fusion device  131  suitable for endoscopic, or minimally invasive, procedures where the instrument operates through a tubular port to gain access to tissues within hollow organs or cavities, the abdomen, the thoracic cavity, and joints. These procedures have various labels, depending upon the location or organ in which the procedure is performed, including endoscopy, laparoscopy, thoracoscopy, arthroscopy, and others. The handle  132  and trigger  133  operate in ways similar to the implementations described above, but now the laser energy pathway, e.g., through a fiber optic cable, transmits the laser energy from an external source or diode mounted in the handle  132  to the distal end  143  through an extended, typically 20 cm to 50 cm, sheath or tube  134 . The tissue to be affected is pinched between a static jaw  135  and a movable jaw  136 , which pivots about hinge  137  when the trigger  133  is actuated. 
         [0048]      FIG. 13  depicts an enlarged view of the distal end  143  of the laser fusion device  131  for endoscopic procedures. Actuation of the trigger  133  causes translation of a tension cable  138 , which is attached to the movable jaw  136  at a second hinge  139  and which causes the movable jaw  136  to rotate against the force of a rotational spring (not shown) about the hinge  137  that normally holds the movable jaw  136  in an open position. Thus, upon actuation of the trigger  133 , any tissue located between the static jaw  135  and the movable jaw  136  will be held fast while the laser is on. 
         [0049]    Laser energy from a laser energy source (not shown) is also activated upon actuation of the trigger  133  and is transmitted through a fiber optic cable  140 . The laser light emanates from the distal end  143  of the static jaw  135  and is reflected towards the tissue held between the jaws  135 ,  136  by an angled reflector  141 . The laser fires for a predetermined amount of time and at a predetermined energy level when the trigger  133  is actuated. The movable arm  136  may further be configured with a reflecting surface  142  at its distal end  143 . The reflecting surface  142  may prevent any laser energy that penetrates the tissue entirely from irradiating undesired tissue locations by reflecting the laser energy back to the same tissue location receiving the incident laser energy. 
         [0050]    Although various embodiments of this invention have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader&#39;s understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the basic elements of the invention as defined in the following claims.