GRANTHAM Hospital is ready to carry out Hong Kong's first heart-lung transplants on two dying patients - if they can find suitable donors in time. The patients, a man and a woman, have waited up to 18 months for the ground-breaking operation which would become a medical milestone and might save their lives. Cardiothoracic Unit chief of service Dr Clement Chiu Shui-wah said the patients' conditions were deteriorating as each week without a donor passed. 'Our worst-case prediction is they could live for another six months. After that something really bad may happen,' said Dr Chiu. 'If they have to keep waiting, there is a great chance that they will not last until the donor appears.' One patient has been living on an artificial ventilator while the other, who has a severe lung infection, is in hospital. But difficulties lie in finding a donor body with infection-free lungs; a perfect heart was easier to find. But both organs must come from one donor. Dr Chiu said lungs from a person who died in a car accident were unusable, because they were usually damaged. 'And if the donor was on a respiratory machine before his death, his lung would already be infected and not suitable for the transplant,' he said. The rarity of good lungs was reflected in the fact that only one lung transplant had been carried out in Hong Kong. Wong Po-pui, 27, the patient who underwent the left-lung transplant at Grantham in July, was healthy, said Dr Chiu. Survival odds for a lung recipient were 70 per cent, but those for heart-lung patients shrank to 60 per cent. 'The latter is more difficult. The chance of over-bleeding is much higher during the operation,' said Dr Chiu. The six months after surgery were also crucial, because of the dangers of rejection or infection. The dead donor had to have the same blood type, tissue type and body size as the recipient. Experience overseas showed one suitable donor emerged from every 10 bodies. For one of the two patients, Cecilia Wong, the one-in-10 probability arrived two weeks ago. But her family's hopes for the unprecedented transplant were dashed at the last minute, when the donor's relatives retracted their offer. 'We can do nothing. Such situations happen all the time,' said Dr Chiu. The two patients who need heart-lung transplants are suffering from a congenital heart disease and bronchiectasis, a lung disease. Surgeons in the United States carried out the first heart-lung transplant. Asian countries such as Taiwan and Japan have also tried the technique. The cardiothoracic unit, formed in 1992, has completed five heart transplants and one lung transplant.