The blood filter removes white blood cells to prevent an immune-system reaction.

From CNN Medical Correspondent Dr. Steve Salvatore

ATLANTA (CNN) -- A simple device called a blood filter could send heart patients home from the hospital earlier -- saving them, and their insurance companies, thousands of dollars.

"It allowed the patients to get out of the hospital an average of a day earlier and saved $2,000 to $6,000 in charges for the procedure," said Dr. John Gott.

Gott, chief of cardiac surgery at Emory-Crawford Long Hospital in Atlanta, was the lead investigator in a study of blood filters on 400 open-heart surgery patients. Results were published in the September issue of the Annals of Thoracic Surgery.

During open-heart surgery, a patient's blood is often pumped through a heart/lung machine. The metal and plastic in the life-sustaining pump can trigger an immune-system reaction in the body, and that can delay healing.

The blood filters used in Gott's study removed white blood cells from the patients' blood. Without the white blood cells, he said, patients are less likely to have an adverse reaction to the heart/lung machine.

"I feel wonderful," said patient Maxie Gibb, whose blood was filtered during heart surgery. "After having the heart operation I had, I couldn't ask to feel better."

Patient Maxie Gibb says the blood filter helped his recovery from heart surgery.

But some are not convinced the procedure ready for wide use.

"I think the science is strong, but I think it needs to be studied in other institutions -- in a larger group of patients -- to recommend this for every patient," said Dr. Steven Macheers, a cardiologist at St. Joseph's Hospital in Atlanta.

For high risk, less stable patients, for whom the filter alone may not be enough, Emory researchers tried an anti-inflammatory drug call aprotinen.

"It decreased inflammation in lab patients, on average, to save up to 11 days on their hospital stay and tens of thousands of dollars in hospital charges," Gott said.

Aprotinen and blood filters are examples of small changes in the operating room that could be big steps toward making open heart surgery as risk-free as possible and cutting recovery time -- both major goals for heart surgeons.