Twelve-week-old conjoined twin girls from Jiangxi province were separated at Children's Hospital of Fudan University in Shanghai on Tuesday. YIN LIQIN/CHINA DAILY

Twelve-week-old conjoined twin girls from Jiangxi province were successfully separated at a Shanghai hospital on Tuesday with the assistance of 3-D printing technology.

Medical checks showed that the girls, weighing a combined 9.55 kg, were connected by soft tissue at the hips. They shared a 10-centimeter anal tube, but had separate digestive systems.

The surgery started at 10:20 am and lasted about five hours.

Pediatric surgery expert Zheng Shan, vice-president of Children's Hospital of Fudan University, who led the surgery, said the operation included body separation, nerve system repairs and anus rebuilding.

Ten doctors, from the neurosurgery, plastic surgery and general surgery departments, participated in the operation.

The hospital pioneered the use of 3-D printing technology in this surgery. It had sent the girls' CT and MRI data information to a 3-D printing company to rebuild the anatomical structure of the conjoined body parts.

"With the 3-D model, we could better understand the actual anatomical structure of the twin girls' conjoined parts. And it helped us to decide on a more precise starting point on the body," Zheng said.

Zheng also said the vaginas of the girls are complete, and their perineal parts are fully established, so their childbearing ability will not be affected.