NEW LASER technology can "map" the depth of burn wounds, saving thousands of children from unnecessary surgery and scarring, the British Association of Plastic Surgeons (Baps) heard yesterday.

The technique employs a laser-scanning machine to produce a surgical map of the burn wound, providing rapid and accurate measurements of the wound depth by measuring blood flow. Both superficial and deep burns are easy for surgeons to distinguish, but intermediate "deep dermal" burns are not. Accurate assessment can ensure patients are either operated on quickly to reducescarring, or are not operated on when it is unnecessary.

"The problem is estimating the middle group," said Anthony Roberts, consultant plastic surgeon at Stoke Mandeville Hospital, speaking at the Baps winter meeting. "Even after 25 years of experience I know I am going to get some wrong - probably about 25 per cent."

The new machine shows up the level of blood flow 1mm to 1.5mm below the surface. Blood flow is high in areas of superficial burns and low in areas of major burns. "We can screen the wound very quickly and map it exactly," said Paul Banwell, Duke of Kent Research Fellow at Stoke Mandeville.

In a pilot group of 40, the doctors estimate that six children have so far been saved from unnecessary surgery. Every year, around 12,000 people are burned severely enough to warrant hospital treatment. Half of these are children but 90 per cent of them receive "deep dermal" burns, compared with about 30 per cent of adult burns.

There are just two machines, which cost pounds 30,000, in the country at the moment - one at Stoke Mandeville and one at Newcastle, but the surgeons said that they would like to see one in every specialist burns unit in the country. "This early work shows that it is a very valuable tool and we should like to see it used throughout the world," said Mr Roberts.