Baptist Hospital has introduced new technology to treat patients with narrowed and blocked arteries that can significantly reduce the chances of a relapse. The private hospital in Kowloon Tong is the first in Asia to apply the technology, called cryoplasty. Three patients have been treated since April. Kenneth Lam Ka-hing, a consultant cardiologist at the hospital, said cryoplasty was similar to conventional angioplasty. In both cases, a catheter is threaded into the clogged artery, where a balloon is inflated to compress the blockage and reopen the vessel. But with cryoplasty, the balloon is cooled to minus 10 degrees Celsius for about 20 seconds. The new method is gentler and causes less scarring of the vessel walls. With conventional angioplasty, a tubular wire-mesh device called a stent is usually used to keep the vessels open, but it sometimes damages or even punctures the vessel. A study in the United States showed that the relapse rate of the new technology in a year was only 12 per cent, compared with 40 per cent for conventional angioplasty. 'The operation is quite simple. It takes only 30 minutes on average and the patient can be discharged the next day,' Dr Lam said. 'But the technology is mainly for treating blood vessels in legs or the lower part of the body only.' He said it could not replace conventional angioplasty in treating coronary arteries. 'The blood vessels in different body parts possess different characteristics,' he said. Conventional angioplasty costs about HK$50,000 to HK$70,000 while cryoplasty costs about HK$10,000 more. Dr Lam said an overseas study estimated that about 12 per cent of the population suffered diseases of the peripheral arteries while those who were aged 60 or above, smoked or had diabetes or other artery diseases were at even greater risk. Narrowed or blocked arteries are usually found in legs and sometimes in arms. Symptoms include pain and occasional numbness in the legs. Chung Wai-hung, 71, was the first to receive cryoplasty in Asia. He began feeling pain in his left leg two years ago and eventually had to take a rest after every 20 or 30 steps. But after the operation in April, he can now walk normally and has no difficulties going up stairs. 'I am happy that I can hang around like normal people now. I even went to Disneyland with my family, walking around the theme park for hours and feeling no pain at all,' he said.