Doctors use a computer-assisted 3-dimensional system for the first time in the country. [Photo/provided to chinadaily.com.cn]

A 3-dimensional computer-assisted system was used for the first time in the country in an operation to separate conjoined twins at the Children's Hospital of Fudan University in Shanghai on Tuesday.

The twin brothers who were born joined at the chest and abdomen were successfully separated after a five-hour surgery and were in a stable condition, the hospital said.

Zheng Shan, one of the operators of the system and deputy director of the hospital, said the difficulty was that the newborns' liver blood vessels were tangled and their livers were interconnected.

"The system presented the 3-D images of the blood vessels in their livers clearly, which played a key role in helping us separate the livers accurately and avoid vascular injury and bleeding," Zheng said.

"The soft tissue of human bodies showed big changes when surgeons moved the bodies in different angles during the operation, but the system helped us a lot in seeing the entire anatomical structure through the rotating 3-D pictures," said Dong Kuiran, the other operator and deputy director of the hospital’s pediatric surgery.

The boys’ mother, from Jiangxi province, gave birth by Caesarean section on Sept 29. They shared one umbilical cord.