Surgeons Zhang Hong, from the First Affiliated Hospital of Jinan University in Guangzhou, and Xiao Zhanxiang, from Hainan Provincial Peoples Hospital in Haikou, responded to a call for medical assistance about 10 hours into the flight, the Guangzhou-based New Express reported on Thursday.
An elderly man was sweating, had a swollen belly and had previously been diagnosed with an enlarged prostate.
Zhang said the man was already showing signs of shock and they estimated that there was about a litre of urine trapped in his bladder.
With six hours of the flight to go, they had to act.
If we had not dealt with the situation in time, the patients life would have been at risk, Zhang was quoted as saying.
They decided to try to puncture the bladder to release the urine using a device cobbled together from materials at hand, including straws from milk boxes.
The flight attendants put blankets on the floor at the back of the aircraft and had the patient lie on his side for the procedure.
The surgeons inserted the needle to release the urine but it was not big enough to ease the pressure on its own.
Zhang then siphoned off the urine himself, drawing out most of the fluid over the next half an hour or so.
He said this was the best way they had to control the flow.
It was an emergency situation. I couldnt figure out another way, Zhang was quoted as saying.
When I saw that the man could hardly bear the pain any more, my only thought was how to get the urine out of his bladder, he said.
After the treatment, the doctors told the man to lie down for another half an hour to recover and check in with a physician after landing.