XI'AN, April 16 -- Doctors from northwest China's Shaanxi Province recently performed a successful and rare tracheal surgery using 4D printing technology on a woman suffering from breathing problem.

According to a press conference held in provincial capital Xi'an on Friday, doctors with Tangdu Hospital inserted a 4D-printed tracheal stent, a tubular support, outside a female patient's collapsed windpipe to keep the airway open.

The 46-year-old female patient had a severe form of tracheobronchomalacia, which causes the windpipe to regularly collapse, preventing normal breathing.

"Her collapsed trachea is inside the thorax and is 6-centimeters long. It is very risky to cut it directly. Placing a stent inside the windpipe is also impossible because the narrowest section is only three millimeters wide," said Li Xiaofei, director with Tangdu's department of thoracic surgery.

The hospital worked with several other institutions, including 3D printing research center with the Fourth Military Medical University, to produce the stent made of a biomaterial called polycaprolactone, which dissolves over time.

"4D printing technology is new," said Cao Tiesheng, director with the center. "It involves 3D printing items that are designed to change over time."

Cao pointed out that for this operation, doctors set the dissolving time of the printed stent beforehand. It will be gradually absorbed by the patient in two or three years. "The patient does not need to undergo another operation to remove the stent."

The patient has recovered and will be discharged from the hospital soon.

"The long-term effects will be observed. But this successful operation will bring changes to other operations," said Li Xiaofei.