Hospital trials dissolvable stents

PUBLISHED : Tuesday, 26 July, 2011, 12:00am
UPDATED : Tuesday, 26 July, 2011, 12:00am


A device to open up narrowed heart vessels that dissolves when it is no longer needed has been used in Hong Kong patients for the first time.

The Bioresorbable Vascular Scaffold (BVS) is implanted in the patient, finds it own way to the narrowed site and stays there for about two years releasing drugs, before dissolving and leaving the widened vessel to function on its own.

It is an alternative to widely used metal stents that remain in the body and can cause inflammation through long-term contact with tissue.

'The BVS is a new concept,' Professor Stephan Lee Wai-luen, clinical chief of the cardiology centre at Queen Mary Hospital, said. 'After the blood vessel has been repaired, the scaffold will gradually dissolve, allowing the vessel to restore regular vasomotor functions.'

He said the hospital had conducted three such operations and the patients were in good health.

The first patient was selected for the study because her condition and the position of the damaged vessel were considered suitable. The 59-year-old suffers from high blood pressure, hyperlipidemia - elevated levels of lipids, including cholesterol in the blood - and diabetes.

The woman sought treatment after noticing a pain in her chest. Tests showed a 70 per cent blockage in her heart blood vessels.

She had two of the new stents implanted and was discharged the next day with no signs of heart pain. The hospital will keep a record of her condition for three years.

BVS uses a polymer manufactured from corn and soy derivatives that eventually transform into carbon dioxide and water, which can then be absorbed by the body.

Because the scaffold does not permanently occupy the damaged site, it is regarded as a better choice for patients with recurring clotting or a need for bypass surgery.

The treatment is not suitable in all cases, however.

'If the [blood] vessel is too long and winding, it might be more difficult for the scaffold to arrive at the right site,' Lee said.

The operations are part of an international study that aims to implant the devices in 1,000 patients worldwide. Queen Mary Hospital, the only participant in Hong Kong, will be in charge of 15 cases.

Lee said the devices might be on the Hong Kong medical market in two to three years, with prices to be announced at the end of next year.