Asia urged to use less invasive heart bypass
HONG KONG, May 12: Doctors in Asia should adopt minimally invasive techniques in harvesting blood vessels for heart bypasses because the traditional open method is exposing patients, many of them diabetics, to risks of infection, Hong Kong researchers say.
In many heart bypasses, the great saphenous vein in the patient's leg is removed and grafted onto the heart, bypassing blocked arteries so as to improve blood supply to heart muscles.
Although this major surgery is common and safe, patients in Asia are exposed to post-operation infection and trauma because of the way the leg vein is removed -- which involves an incision running from the ankle to the top of the inner thigh.
Incisions could be as deep as 2-inches (5 cm) for overweight patients.
In contrast, half of hospitals in the United States use minimally invasive endoscopy to harvest the vein, which requires only three to four small skin incisions of about 2-cm each.
Timmy Au, a consultant cardiothoracic surgeon at Hong Kong's Grantham Hospital, said the old method should be done away with as Asian bypass patients, especially Chinese, are less able to cope with infection because many also suffer from diabetes.
In a survey, Au and his colleagues conducted between March 2005 and January 2006, up to 40 per cent of 74 bypass patients at their hospital were diabetic, a rate which is twice that normally found in Western countries.
''We know the incidence of diabetes in Chinese bypass patients is much higher than in western or European patients.
So the risk of infection is very high,'' Au said.
''And in places where the weather is hot and hygiene is an issue, infection risk is even higher,'' he added.
Infections are frequently more dangerous in someone with diabetes because the body's normal ability to fight infections is impaired. To compound the problem, infections can worsen glucose control, which further delays recovery from infection.
In the survey, only one of 39 patients who were randomly chosen to undergo the less invasive method ended up with leg infection, while four of 35 people who underwent the open method suffered infection.
''These patients (suffering infection) needed antibiotics, their conditions were serious,'' Au said.
''The risk is mainly leg wound infection, but if the infection is in the body, the germs will spread somewhere else.
The worst-case scenario would be if the bacteria or germs spread to the chest wound, over the heart.'' ''Severe infections are rare, but once it happens it can be fatal,'' he said. Of those who suffered infections, between one to five percent were severe cases, he added.
While the new less invasive method steadily became entrenched in richer nations in the West from the late 1990s, cost has been an obstacle in the east, Au said.
''But if you can cut the infection rate, that would reduce post-operation care and the overall cost will be lower.''