A Shanghai court has begun hearing claims against a city hospital accused of cajoling a couple into letting their son undergo what they say was an unnecessary, experimental heart operation. The boy died 15 months after having the surgery. Zhou Zhenhua and his wife, Guo Yongbei , told Xuhui District People's Court on Monday that Shanghai East Hospital director Liu Zhongmin said that there was a more than 90 per cent chance the surgery to install an 'artificial heart' in their son, Zhou Yiqing , 12, would be successful. Yiqing had been diagnosed with a serious heart ailment at Shanghai Children's Hospital in April 2004. The children's hospital said it could not treat the condition, referred him to Shanghai East Hospital and invited Dr Liu to make a diagnosis. According to the parents' lawyer, Zhang Shengfu , Dr Liu told the parents the boy had to undergo an 'artificial heart' operation; otherwise, he could die within days. Mr Zhang said the boy had an operation that month to connect his heart to an external machine to regulate his heartbeat, before undergoing stem cell surgery two months later and a heart transplant in July 2005. He died after 15 days in a coma following the transplant, according to Mr Zhang. The couple are demanding 990,000 yuan in compensation from the two hospitals. 'The parents did not know that that type of 'artificial heart' surgery was ... still in the research stage,' Mr Zhang said. 'If they had known there were risks from this operation, they would definitely have refused Liu's request.' The parents became suspicious about the surgery when Shanghai East offered to waive more than 400,000 yuan in medical expenses after the boy's death. It asked them to sign a document promising never to release information about the treatment to the media, file a lawsuit against the hospital or inform the government. According to the lawyer, the artificial heart machine, imported from a German medical company, was not registered by the State Drug and Food Administration and was used illegally in the procedure. Neither hospital could be reached for comment yesterday.