Wang closes up the right half of the cut with three stitches, black thread standing out against the rabbit’s pink skin. Then she takes a vial of Rose Bengal and drips the neon-pink dye onto either side of the unclosed portion of the wound. She threads the laser’s fiber-optic cable into a metal stand, which maintains a set distance between laser and tissue while holding the light steady; a lens focuses the beam into a sharp, straight line that can be aligned with the incision. Wang positions the stand on the rabbit’s flank, dons a pair of orange safety glasses, sets a timer, and steps down on the pedal that activates the laser. A green glow washes over the room.
Three minutes later, the timer beeps and Wang releases the pedal. She removes her safety glasses, moves the laser stand away, and inspects her handiwork. A small line is visible–a remnant of the Rose Bengal stain and of the black marker used to trace the location of the incision prior to surgery. But when she tugs on the wound, using a pair of forceps in each hand to pull the skin apart, the skin holds taut, and there’s little visible evidence of the cut itself.
A Bright Future
“It’s a very interesting technology, which would be useful to anyone who does any kind of skin surgery–plastic surgeons, dermatologists,” says Robert Stern, a professor of dermatology at Harvard Medical School and chief of dermatology at Beth Israel Deaconess Medical Center in Boston. He notes that the technology must still prove itself, and he isn’t yet convinced that the benefits will offset the costs of photochemical dyes and laser equipment, which are far pricier than a needle and thread. But, he says, the potential to minimize scarring and perhaps speed healing “could be nice for patients and improve outcomes [too].”
So far, use of the technique in humans has been limited to skin surgeries: in a clinical trial, 31 patients with skin cancers and suspicious moles had their three-to-five-centimeter excisions closed with sutures on one side and photochemical tissue bonding on the other. The dermatological procedure will be submitted to the U.S. Food and Drug Administration for approval, which the researchers are awaiting before beginning additional human trials. Animal experiments have already shown the technique to be useful in nerve, eye, and blood vessel surgeries, among others–so useful, in fact, that Kochevar and Redmond have surgeons ready and waiting to start human trials the moment the hospital approves them.
“Talk to just about any physician about this, and they have an idea for how it could be used,” Kochevar says. The technology is limited by tissue depth: it works only where light will penetrate, so it could never replace subcutaneous sutures or be effective on dark or opaque tissue like liver and bone. The scientists have licensed the technology to a brand-new startup, still in stealth mode, which plans to commercialize the technology once it receives FDA approval. The company has just begun seeking its first round of funding.