It's like looking through a window. It's that clear

Dr Steven Palter, Yale School of Medicine

The surgeon uses these pictures to navigate around the maze of internal organs and other structures in the body, and find exactly the right place to make an incision.

Although keyhole operations are not without their own risks, they can offer shorter stays in hospital, and quicker recovery times to patients.

Previously, the latest high definition cameras were too large and expensive to be placed right at the end of the endoscopes.

Instead, the endoscope works like a telescope, with a viewer at the surgeon's end - normally, a camera is attached here to relay pictures to a television monitor.

Dr Steven Palter, assistant professor of obstetrics and gynaecology at Yale School of Medicine in the US, told a conference this week that he had carried out five operations using the new probes.

Twice as good

He said the sharpness of the picture fed back to the surgeon was double that of current technology.

He said: "High-definition television provides more than double the previous resolution, from less than 500 lines to more than 1,000 lines.

"It's like looking through a window. It's that clear.

"When you use HDTV in surgery, you can see tiny details and structures that were not visible before.

"We believe that this will translate into increased accuracy, decreased errors and decreased surgeon fatigue, which are the advantages of the HDTV system."

Some common gynaecological operations are carried out using keyhole techniques.

A UK surgeon experienced in endoscopic surgery, John Calvert from Swansea's Singleton Hospital, said that provided enough money was spent on good quality existing technology, the picture that could be achieved was "better than the naked eye".

"I can't really see the full advantages of having the camera 'on the business end' of the endoscope, if that is what is happening here."