He has been using the 8-0 sutures, the most delicate and fine surgical stitches for heart surgeries, ever since he came back to the hospital in 2000.

"For the anastomosis (or connection) of tiny coronary blood vessel in heart surgery, the 8-0 sutures can maintain better blood flow to the heart compared with other size of threads," Cheng said.

This is a challenge for a surgeon because he has to be very gentle in the process when connecting the blood vessels of 1.5-2.0mm with this kind of fine sutures, either not too loose or not too tight.

Cheng is one of the five surgeons who use this technique in almost every case of coronary bypass operation in China, according to Dahe Daily.

"It's good for the patient's recovery," Cheng said.

He received The Golden Knife Award from Chinese Association for Cardiovascular Surgery in 2012.

Meanwhile, Cheng has been ranked among the top 10 surgeons in the field of coronary artery bypass surgery in China for the past four years.