VOA常速英语:New Laser Heals Wounds Faster, Without Scarring

All surgical patients want their wounds to heal quickly with the least possible scarring. But traditional stitches, clips and more modern chemical glues all have their own disadvantages. Israeli scientists say they have developed a laser that bonds tissue in a way which leaves almost no trace.

For decades, doctors have known that cuts in living tissue can be “welded” together by heat. But keeping the temperature of the welding tool constant proved to be a daunting problem, according to Abraham Katzir, head of Tel Aviv University’s Applied Physics Department.

"If you heat a spot on an incision to temperatures lower than say 50 or 55 degrees centigrade nothing happens. If you are above 65 degrees than you cause scarring," he said.

A team led by Katzir developed a laser that can project a spot of infrared light, or heat, and at the same time precisely control the temperature of the targeted tissue.

"We carried out experiments on a large number of tissues, on skin, on cornea, on blood vessels and so on and we have gradually improved," said Katzir.

The heat transmitted through a single optical fiber makes the molecules of collagen - the main structural protein of all connective tissues - bond and close the wound.

Ichilov Medical Center ophthalmic surgeon David Versano says this makes the new tool suitable for microsurgery on blood vessels and nerves. The method has been used successfully to heal incisions in corneas taken from dead cows.

“The advantages of the procedure are that we can get bonding to be probably much stronger than with sutures," he said. "We hope that the scarring will also be less than with sutures and eventually we'll get the safety of the procedure to be better."

Wounds of 10 human patients treated with the laser technique have healed with minimal scarring. Researchers say with additional refinements, the new surgical tool may soon be in wider use.