Prosthetic reconstruction utilizing a 2-stage saline tissue expander-to-implant procedure is the most common technique for breast reconstruction in the United States. For nearly the past 50 years, 2-stage breast reconstruction using saline tissue expanders has been the standard of care. However, in December 2016, a carbon dioxide–filled, remote-controlled tissue expander received U.S. Food and Drug Administration clearance. This tissue expander, known as the AeroForm Tissue Expander System (AirXpanders, Inc., Palo Alto, Calif.), is a novel, patient-controlled, needle-free expander operated by a wireless remote control device, which allows patients the comfort and convenience of home expansion, precluding the need for percutaneous saline injections. A multicenter, randomized, prospective clinical trial has revealed statistically significant shorter times to full expansion as well as shorter overall reconstructive times. It is the first tissue expander device designed successfully with an alternative filling medium to saline, namely carbon dioxide. This CO2-filled expander thus provides several potential advantages over previous expander designs, including patient-controlled expansion, obviation of saline injections, and shorter expansion times.