It may sound like something you would see on a futuristic television show, but "laser stitches" – formally known as photochemical tissue bonding or laser-assisted nanosuturing – are already being used to close human wounds.
Researchers at Massachusetts General Hospital are using light to "stitch" surface wound openings back together. They do so by shining a light from a KTP green laser onto the skin after each side of the opening has been coated with Rose Bengal, an opthalmological dye approved by the FDA. When the light reacts with the dye, a continuous bond is created, reconnecting collagen in the skin tissue without heating the skin. The result? A watertight seal that requires no return visit to the doctor’s office for suture removal.
"One way to describe how laser-assisted nanosuturing works is to think of the difference between Velco fasteners on shoes and shoe laces," explains Irene Kochevar, chemist and co-inventor of the technology with Robert Redmond in the Wellman Center for Photomedicine at Mass General. "With the laser, you attach the tissues using a huge number of nanosutures whereas traditional suturing leaves small gaps in the wound closure."
No allergic reaction
While Dr Sandy Tsao, a dermatologist in the Laser Center at Mass General, is still testing this treatment in a clinical trial, those being studied have had far less inflammatory response than they do to traditional stitches, as there is no allergic reaction to a foreign body being introduced to the skin.
As well as reducing inflammation, photochemical tissue bonding may also reduce the chance of infection post surgery. Since there are no openings in the skin, access to pathogens that might otherwise make their way through is blocked.
Patients also experience a cosmetic perk with this new method of suturing. Those in the study had half of the wound closed using traditional suturing and the other half using the laser. In all patients, the laser-treated side looked better than the other. There are no worries of having cross-hatch marks from actual stitching; instead, patients are left with only a single line. Patients were observed over a six-month period, with the appearance of their wound closure documented at two weeks post surgery, three months and six months.
"We’re so grateful to the patients who volunteered for the study," says Kochevar, "Despite their busy lives, they came back to be observed. We couldn’t have done such good research without them."
Kochevar says future hopes for the technology would include creating a light source small and portable enough for all dermatologists to be able to use it in the clinical setting, as well as cutting down treatment time. It only takes about three minutes to close the wound at present, but the Kochevar and Redmond team is always looking to improve and would like to see the time reduced to less than 30 seconds. Kochevar forsees that this technology will expand beyond the skin’s surface to repair intricate tissues such as cornea and nerves that are damaged by conventional suturing, and which require extremely high levels of surgical skill for repair.
"We’re very excited about improving surgical outcomes," says Kochevar, "and possibly making new surgeries available, by using light to seal and connect delicate tissues with minimal scarring."
(Source: Massachusetts General Hospital: September 2009)