Laser healing method and apparatus

#This invention relates generally to methods and apparatus for closing wounds and more particularly, to a method and apparatus for applying optical energy to biological tissue whereby the tissue is converted to a collagenous, denatured protein substance which joins severed tissues and closes wounds.

#Historically, suturing has been the accepted technique for rejoining severed tissues and closing wounds. Suturing has been achieved with a surgical needle and suturing thread, and more recently, with a variety of polymeric or metallic staples. The intended function of sutures is to hold the edges of the wounds against one another during healing so as to reduce discomfort, pain, scarring, and the time required for healing.

#It is a problem with known suturing systems that since they are applied intermittently along a wound, they permit gaps in the wound between sutures to remain open thereby accepting dirt and bacteria. Moreover, in addition to producing a relatively high risk of infection and tissue rejection, such gaps between sutures are eventually filled in by keloid, which results in disfiguration and scarring. In addition, inflammation often results from the foreign body presence of the suture material.

#Embodiments of the invention have been chosen for purposes of illustration and description, with reference to the accompanying drawings, wherein:

#FIG. 1 is a schematic view of a laser surgical system for use in accordance with the invention;

#FIG. 2 is a side sectional view of the hand-piece of FIG. 1;

#Biological tissue comprises cell layers in a protein framework for tensile strength. All proteins are amino acids which have side chains which are dissolvable either in water or fat. Naturation is a process wherein the amino acids fold over, always in the same configuration for each protein type, when the protein leaves the interior of a cell and is confronted with tissue water. In such case, the hydrophobic portion of a side chain folds to the interior of the molecule. The proteinaceous components of the tissue can be unfolded or denatured by the application of heat.

#As stated in copending application Ser. No. 539,527, it has been discovered that application of optical energy to biological tissue, in a nondestructive amount sufficient to generate enough heat to denature the proteinaceous components, can be used to cause the body's own tissues to substantially reproduce the prior tissue structure at a wound or severed tissue site. In particular, energy from an optical energy source, such as a laser, can be applied to bring the temperature of biological tissue somewhere above room temperature, but below the point of water; preferably above 45 degrees centigrade and particularly to about 60-70 degrees centigrade. Collagen, a major source of protein in the body, is denatured by application of such energy in such a way as to go into solution and form a "biological glue" to seal a lesion, anastomize a severed vessel, or reconstruct damaged tissue. When the source of heat is removed, the proteins begin to re-nature and form an approximate replication of the prior tissue structure. As the body heals, the so-called "biological glue" will be reabsorbed and replaced by natural tissue.

#The application of heat, to form a collagenous seal to immediately close a lesion or anastomize a severed vessel accelerates healing time, leaves little or no scarring, preserves the tissue, and avoids inflammation and/or infection caused by the inclusion of foreign suture material in a wound.