FDA Approves New Tissue Expander for Breast Reconstruction After Mastectomy

Wireless controller allows patients to expand device at home

The FDA has allowed the marketing of the AeroForm device (AirXpanders), a new tissue-expander system for soft-tissue expansion in two-stage breast reconstruction after mastectomy and in the treatment of underdeveloped breasts and soft-tissue deformities. The patient uses a dose controller to independently inflate the expander.

A tissue expander is a balloon-like device that has a soft, expandable polymer shell and is gradually filled with saline or air. Tissue expanders are typically used before breast reconstruction to cause breast tissue and muscle to stretch over time, which creates a space for the breast implant.

The AeroForm device is a wireless tissue expander for patients who choose to have reconstructive surgery after a mastectomy. Most women who have mastectomies to treat or prevent breast cancer are eligible for breast reconstruction.

The AeroForm system has two main components: a sterile implant with an outer shell made of silicone (the expander) and a remote dosage controller. The expander contains a reservoir of compressed carbon dioxide. The controller is a hand-held device that communicates with a receiving antenna and electronics located in the expander. The controller is used to communicate to a valve in the reservoir to release carbon dioxide and gradually inflate the expander. The controller is preprogramed to release a small amount of carbon dioxide once every three hours, up to a maximum of three times per day.

The AeroForm device differs from available saline-filled tissue expanders. Saline expanders are expanded by the surgeon, who uses a needle to pierce the skin and inject saline into the expander through a port or injection area. The AeroForm expander is filled with air; there is no need for a needle, and the patient has control over slowly expanding the device at home.

The FDA reviewed the results from a clinical trial in which 99 patients used the AeroForm expander and 52 patients used the saline expander. The results showed that 96% of patients using AeroForm expanders and 99% of those using saline expanders were able to have their breast tissue successfully expanded and exchanged to a breast implant.

A surgeon must determine whether the patient is a suitable candidate for treatment with the device. Patients must not have any residual tumor at the expansion site and must not undergo magnetic resonance imaging (MRI) while the device is in place. Patients with another electronic implant (e.g. a pacemaker, a defibrillator, or a neurostimulator device) are not eligible for treatment with the AeroForm tissue expander.

The most common adverse events seen in the clinical trial included necrosis, seroma, postoperative wound infections, and procedural pain. Patients using the AeroForm device did not report any serious adverse events.

The FDA reviewed the clinical data for the AeroForm system through the de novo premarket review pathway, a regulatory pathway for some low- to moderate-risk devices that are novel and for which no legally marketed predicate device is available for comparison.

Source: FDA; December 21, 2016.