sketch 2By Khashayar Mohebali, MD

With the passing of the Women’s Health and Cancer Rights Act in 1998, breast reconstruction has become an accessible and affordable part of breast cancer treatment for American women. In 2014, 102,215 women in the United States underwent breast reconstruction; up 7% from the previous year and 30% since 2000. Although autologous reconstruction is an option, most women choose implant-based reconstruction, typically done as a two-staged procedure with placement of a tissue expander to stretch the skin, followed by placement of implants.

Although tissue expansion has been used successfully for the past 50 years, the existing saline-filled expanders still have some limitations. Women must undergo a series of saline injections in the physician’s office to inflate the expanders, a process which is reported to be uncomfortable, inconvenient, and lengthy. The treatment of breast cancer and the reconstruction process is grueling, time-consuming, and costly. Women who do not opt for breast reconstruction may fear the process and the protracted length of time to complete the reconstruction. Innovation in the area of tissue expansion has been sought for many years.

About the AeroForm Tissue Expander System

The AeroForm Tissue Expander System (AirXpanders Inc, Palo Alto, Calif) was developed by a plastic surgeon to provide an alternative, convenient method of tissue expansion that could provide gradual controlled filling of the expander, eliminate needle injections, reduce the time and resources for office fills, reduce the risk of infection and inadvertent expander punctures, and ease patient anxiety and discomfort. The device is designed to allow small-volume, gradual expansion from an internal reservoir filled with carbon dioxide. The expander is operated by a radio-controlled valve that, when activated by a remote control, releases a programmed volume of carbon dioxide into the expander, completely eliminating the need for percutaneous injections.

In August 2015, AirXpanders filed a 510(k) notification with the US Food and Drug Administration (FDA). AeroForm® has CE Mark and Therapeutic Goods Administration (TGA) approval and is covered by the Australian reimbursement regime.

Clinical Trial Results

Anthony Connell, MD, of Mount Hospital in Perth, Western Australia, reported on the first human experience with the AeroForm System in the PACE 1 (Patient Activated Controlled Expansion) trial in 2011. In the study, 10 expanders were implanted in seven women. This PACE I trial demonstrated proof of concept with successful tissue expansion in less than 2 weeks for expanders of a variety of sizes (400 cc, 650 cc, and 850 cc), much less than the time it typically takes using saline expanders.

In PACE 2, a continuation trial published by Connell, 61 expanders were implanted in 33 women along with a pedicled latissimus dorsi flap for expander coverage. Overall, Connell reported a 100% expansion success rate and an average expansion time of 17 +/- 5 days.

In the recently published ASPIRE Trial, Connell implanted 34 additional devices in 21 patients with a broader range of eligibility criteria, including women with a history of previous radiation. He reported a 94% success rate with two failures noted that were related to flap failure. Three patients with a history of prior radiation therapy were included in the trial, with good outcomes.

In the United States, the AeroForm System has been evaluated in a multi-center, randomized, controlled clinical trial, AirXpanders Patient Activated Controlled Tissue Expander System for Breast Reconstruction (XPAND), designed to directly compare the AeroForm device with saline expanders. The device has undergone design changes to reduce overall expander size, decrease CO2 loss, and improve the reliability of the communication system and internal valve.

The XPAND study is currently the only trial to date directly comparing CO2-based expansion with saline-based expansion. One hundred fifty patients were treated in this trial at 16 centers across the United States, randomized using a 2:1 ratio to either the investigational patient-controlled tissue expander or the saline expander control group, respectively. The primary endpoint for the trial—successful expansion and permanent implant exchange unless precluded by a non-device related event—was met. The final trial results will be presented by Jeffrey Ascherman, MD, chief of plastic surgery, Columbia Presbyterian Medical Center and principal investigator for the XPAND Trial, at the 2015 American Society of Plastic Surgeons Meeting.

There were some lingering questions about how the new technology meshes with radiotherapy and/or air travel, but studies suggest that both are safe for AirXpander patients. The device can withstand a cumulative dose of more than 75 Gy (well beyond the amount delivered during typical radiotherapy regimens for patients who have had mastectomy), and successful radiotherapy can be delivered to the chest wall and surrounding area even with the AeroForm device in place. Patients were grounded from air travel during the early days of the trials due to concern about how—or if—altitude would affect the device, but this restriction has since been relaxed.

The PACE / ASPIRE trials and topline data from the XPAND trial are promising, showing patient and physician satisfaction and shorter expansion times with CO2– filled devices. The company is looking forward to marketing this new technology to all women undergoing breast reconstruction in the near future.

mohebali_HIRES.jpgKhashayar Mohebali, MD, is a board-certified plastic surgeon in Marin County, Calif. He serves as both the Chief of the Department of Surgery and the Chief of Plastic Surgery at Marin General Hospital. He can be reached via [email protected]com.