Clinical study tests less painful breast reconstruction method

Tissue expander system stretches skin and tissue at the site of mastectomy using carbon-dioxide

May 02, 2012


   John Castle, MD

UMass Medical School and UMass Memorial Medical Center have enrolled their first participant in a clinical study designed to evaluate a new tissue expansion method for breast reconstruction after a mastectomy. The randomized, controlled clinical study is designed to directly compare the outcomes of the traditional saline tissue expansion method to an investigational, remote-controlled, needle-free, tissue expansion system known as The AeroForm Patient Controlled Tissue Expander System.


Tissue expansion is a process required to stretch the skin and tissue at the site of a mastectomy so that a standard saline or silicone breast implant can be placed.

“Traditionally, women undergoing breast reconstruction have had to endure a long process of inconvenient and often painful inflations using conventional saline expanders to create a pocket for a standard implant following a mastectomy,” said John Castle, MD, clinical assistant professor of surgery and plastic surgery director at the UMass Memorial Comprehensive Breast Center. “This investigational system eliminates the need for saline injections by allowing the patient to trigger the release of small amounts of compressed carbon-dioxide through the valve of a tiny chamber located inside the expander. The patient uses the remote control to gradually inflate the investigational expander in small, pre-set amounts on a daily basis at home, eliminating the need for weekly doctor visits.”

Participants in this clinical trial will undergo outpatient surgery to have the investigational tissue expansion device implanted. They will then use a wireless dose controller to trigger the release of small, regulated amounts of carbon-dioxide to fill the tissue expander, according to a protocol directed by their surgeon. Once the tissue is adequately expanded, participants will return to UMass Memorial Medical Center to have the implant surgically inserted. During earlier feasibility trials, the average expansion time associated with the remote-controlled tissue expander was 15 days, a fraction of the time required using traditional expanders, which can take months to achieve full expansion.

Patients in the study will be randomly selected to receive the investigational expander or a traditional saline expander. The patients who receive the investigational expander will use a wireless remote control to trigger the release of small, regulated amounts of carbon-dioxide to fill the tissue expander, according to a protocol directed by Dr. Castle. Once the tissue is adequately expanded, the patient will return to have the expander removed and a standard implant placed.

The current standard of care in tissue expansion involves implanting a saline expander under the skin and pectoral muscle following a mastectomy procedure. The patient returns to her doctor weekly for bolus saline injections, which many patients say is the most painful, difficult part of the reconstruction process. The traditional saline process can take as long as five to six months.

UMass Memorial Medical Center and other hospitals across the United States are participating in the study. Enrollment will continue until a total of 92 AeroForm expanders and 46 saline expanders have been implanted in patients. Aeroform will be evaluated based on its ability to successfully and safely expand the tissue to the point that the expander can be replaced with a standard breast implant. Secondary measurements will include the average number of days needed to achieve the desired expansion, total reconstruction time, pain and patient satisfaction.