New, Improved Breast Biopsy Devices Being Tested at Stanford

Two new devices for performing breast cancer biopsies, which may help physicians locate and remove abnormal breast tissue causing less pain and interference with normal tissue, are being tested by researchers at Stanford University Medical Center.

"Because of mammography, cancers are being detected before they can be felt," said Dr. Frederick Dirbas, assistant professor of surgery. "The question is, can we create new tools that precisely remove these smaller tumors with less damage to surrounding tissue."

Dirbas is testing a new device called SiteSelect. The doctor guides the SiteSelect device to the suspect tissue, using a mammogram image for direction. When the device nears the suspect tissue, the doctor slides the outer shell of the device over the area, separating the suspect tissue from the surrounding tissue, and removes it. The procedure requires a local anesthetic, one or two stitches, and is less disfiguring than a traditional mammotome, the current procedure for this type of biopsy.

"You may take out a similar volume of tissue compared to the mammotome, but because it's in one piece the pathologist may be able to give you a more accurate answer," said Dirbas. The mammotome take about 10 tiny samples of breast tissue, but because each sample is so small, the procedure can miss cancerous tissue about 3 percent of the time.

Dirbas is hopeful that the SiteSelect device, made by Imagyn Medical Technologies, Inc., may one day be used to remove entire tumors.

A second device, manufactured by Vivant Medical, Inc., is being tested by Dirbas to help locate suspect tissue during a surgical biopsy.

When removing breast tissue, surgeons need guidance to help locate abnormalities that appear on a mammogram but are invisible to the naked eye. To locate the abnormal tissue, doctors use a J-wire that points to the exact location. Surgeons then remove the tissue surrounding the J-wire, some of which may be healthy tissue.

The new Vivant device helps doctors remove only the suspect tissue while leaving the healthy tissue behind.

The Vivant device consists of a narrow needle and a coiled ribbon. When the tip of the needle is near the abnormal tissue as shown on the mammogram, the doctor releases the ribbon, which wraps around the abnormal tissue. After a second ribbon is released, the two ribbons form a basket around the abnormality, showing which tissue should be removed.

Other sources: Stanford University Medical Center