Natural cellulose better for heart bypass surgery

Bacterial cellulose could be used for artificial blood vessels in future as it carries a lower risk of blood clots than synthetic materials currently used in bypass operations, says a new study.

Produced by a bacterium known as Acetobacter xylinum, the cellulose is strong enough to cope with blood pressure (BP) and works well with the body's own tissue.

"There are hardly any blood clots at all with the bacterial cellulose, and the blood coagulates much more slowly than with the materials I used as a comparison," says molecular biologist Helen Fink, who presented her thesis for MD in medicine at the Sahlgrenska Academy, Sweden.

"This means that the cellulose works very well in contact with the blood and is a very interesting alternative for artificial blood vessels."

Real blood vessels have an internal coating of cells that ensure that the blood does not clot. Helen Fink and her colleagues have modified the bacterial cellulose so that these cells adhere better.

"We've used a brand new method which allows us to increase the number of cells that grow in the bacterial cellulose without changing the material's structure," says Fink.

Hardening of arteries, which blocks coronary vessels around the heart, necessitates a bypass operation of which 6,000 are carried out in Sweden every year, said a Sahlgrenska release.

The surgeon takes a section of a vein, say from the patient's leg, and uses it to divert the blood around the hardened artery. Where patients do not have any suitable vessels, a vessel made of synthetic material is used instead.