For instance, laser tissue welding, an optical technique for wound closure during micro- or minimally invasive surgeries, is currently under development in several hospital research institutes in North America and Europe. The medical community's demand for surgical lasers will continue to increase with a widen range of applications which run from excising cancerous tissue through to cosmetic surgery. Capabilities Medical research into wound closure with adhesives has been ongoing for some time. However, until recently there have been significant barriers in developing glues which will set rapidly in pliant tissues at precisely the instant the tissue is correctly aligned. Thus, research has been focused on developing photosensitive glues which can be activated quickly when the tissue pieces are approximated correctly without also delivering damaging thermal or electrical energy to the surrounding tissue.
Laser light can selectively penetrate tissue and activate glue inside an incision.
When the glue is mixed with light-absorbing chromophore the energy will be deposited only in the glue, and not the tissue. The two principle approaches are thermal tissue welding, usually using an non infrared laser at 800 to 1600 nm, and photoaffinity labeling using ultraviolet or blue light. In order to concentrate the laser energy to the weld site, and in an attempt to decrease the thermal injury to the surrounding tissues, chromophores such as indocyanine green and solders such as albumin have been used. The albumin denatures, and just like egg white, will form a solid bridge across the anastomosis allowing for collagen bonding. In the photoaffinity labeling approach, the glue is activated via photochemical processes creating chemical bonds between the two tissues.