DES MOINES, Iowa -- Tiny robotic surgical equipment was made even tinier to handle the youngest and smallest patient yet to be treated using the technology: a 5-day-old, 8-pound boy who had a cyst pressing against his lung.

David Dornbusch underwent the surgery a week ago at Blank Children's Hospital and was sent home five days later, doctors said Tuesday. The surgery to remove the cyst required just four incisions, each about the size of a dime.

"It's just like little cat scratches that are healing on their own. He didn't even need stitches," said David's mother, Colette Evans, 20, of Des Moines.

David's surgery demonstrates that the technology can be successfully used on babies, said pediatric surgeon Dr. Michael Irish, a neonatal specialist who conducted the procedure using a da Vinci robotic surgical system. The surgery required the designers of the system to shrink the scope that carries the camera inside the body from 8 millimeters wide to 5 millimeters.

"Now we know we can do this," Irish said. "It helps advance us to the next stage."

Prior to David's surgery, the youngest patient to undergo robotic surgery was 4 months old, and the smallest weighed just under 15 pounds. Both had surgery at Blank.

In May, a 6-pound baby underwent surgery at a Tennessee hospital using a robotic surgical system in conjunction with more traditional laparoscopic surgery, Irish said. In laparoscopy, doctors also perform surgery through small incisions, but they control the instruments used more directly than they do in robotic surgery.

The robotic system allows doctors to see inside the body in three dimensions and operate using tiny precision instruments that they can maneuver by moving their hands in a more natural way than they can in laparoscopy. Minimally invasive operations generally allow patients to recover faster and with less pain and scarring.

The cyst first appeared as a shadow on an ultrasound when Evans was about 20 weeks into her pregnancy. The cyst had been pushing on David's left lung and an airway, and also threatened his heart, doctors said.

The $1 million da Vinci system is controlled by a surgeon who sits in front of a console to maneuver the three arms of a 6-foot robot hanging over the patient.

A tiny camera is inserted into the patient's body. Looking into a hooded monitor, the surgeon can look inside the body while controlling various tiny instruments -- such as scissors, scalpels and a cauterization tool -- inserted into the body through hollow tubes.

"You feel as if you're submerged in the chest, like you're in a virtual environment, but it's very real," Irish said.