French surgeons used computers and robots to perform open heart surgery on six patients this month, a technique that doctors say could result in less trauma and pain for the patient.

The first operation took place on May 7 at Paris' Broussais Hospital, followed by five other successful heart operations using the same technology, the hospital said.Developed by Intuitive Surgical of Mountain View, Calif., the technology "lets us perform difficult, even (heretofore) impossible, gestures," Dr. Alain Carpentier, who lead the team of French doctors, said Thursday.

"It's a revolution, a formidable step forward," said Carpentier, who performed the surgery with Dr. Didier Loulmet.

Speaking at a news conference, Carpentier said that higher precision is among the benefits of the system officially called computer-assisted instrumentation.

The system uses "mini-incisions" and is less traumatizing and less painful than traditional techniques, but also more difficult, a hospital statement said.

Several of the six patients, all adults, suffered from heart valve disease. The first patient had a defect involving communication between the heart's two upper chambers.

Using the system, the surgeon sits at a console several yards from the patient, peering inside the heart via a three-dimensional camera inside the patient and directing a robot that actually performs the surgery.

The surgeon's gestures are transmitted by computer to the robotic tools, which "faithfully reproduce all movements of the surgeon," Carpentier said.

Dr. Philip Oyer, professor of cardio-thoracic surgery at Stanford University, said the computer-assisted technique is part of a new trend of minimally invasive surgery. Much of the early promise of the techniques has not been borne out, however, he added.