Luincys Fernandez demonstrates how she used the AeroForm handheld dosage controller, a device doctors are testing that would let women contribute to the breast reconstruction process at home. The palm-sized remote control activates a tiny cartridge to pump gas inside a pouch gradually enlarged to stretch the remaining skin and muscle. The process is aimed at not only making treatment more comfortable and convenient, but also giving women a sense of control, something cancer often takes away.

Doctors are testing a device that would let women do part of their own breast reconstruction at home.

It’s aimed at not only making treatment more comfortable and convenient, but also giving women a sense of control — something cancer often takes away.

More than 100,000 women each year in the United States have surgery to remove a cancerous breast, and many of them choose reconstruction with an implant. To make room for a permanent one, many of them get a tissue expander, a temporary pouch that is gradually enlarged with saline to stretch the remaining skin and muscle. This means trips to the doctor every week or two for several months for injections of saline into the pouch, which can be painful.

“We would put as much saline as we could until basically the patient would say, ‘I can’t stand it anymore,’” said Dr. Daniel Jacobs, a Kaiser Permanente plastic surgeon in San Jose, Calif.

While biking home one day, Jacobs had an idea: Why couldn’t a tiny can of compressed gas, like the one he carries to fix a flat tire, be used to let women inflate their own tissue expanders, a little each day so there is less stretching at a time and less pain?

He helped found a company — AirXpanders of Palo Alto, Calif. — to develop the device, called AeroForm. It’s sold in Australia, approved in Europe, and under review by the U.S. Food and Drug Administration. Its use requires just a palm-sized remote control that activates a tiny cartridge inside the pouch to pump gas, up to three times a day according to how the woman feels.

In a company-sponsored study of 150 women, AeroForm patients finished tissue expansion in half the time and were able to get implants a month sooner than others who had the usual saline treatments, said the study leader, Dr. Jeffrey Ascherman, a plastic surgeon at New York-Presbyterian/Columbia Medical Center in New York.

There was no difference in rates of side-effects such as infections, but seven of the air expanders malfunctioned versus only one saline one, Ascherman said.

The device comes in three sizes. Women can choose the amount of inflation up to a point, limited by how much tissue is left and how far the device can expand. Once fully expanded, the device is removed and replaced with a breast implant.

In the U.S., tissue expansion generally is reimbursed at a flat rate that is part of breast reconstruction, and AeroForm’s impact on this cost — if the device wins FDA approval — is not clear.