AeroForm Tissue Expander: A Case of Early Accidental Inflation

Device-based reconstruction, the most common approach to breast reconstruction, typically occurs in 2 stages to allow for the breast envelope to be expanded serially before exchanging for a permanent implant. The AeroForm tissue expander is a carbon dioxide-based expansion system that allows for patient-initiated filling, and compared with the traditional saline expander, it has been shown to decrease the median time to full expansion and implant exchange. Furthermore, multiple changes have been incorporated into the newer V2.5 iteration resulting in reductions in device-related malfunctions, including overinflation.

A 57-year-old woman who had a diagnosis of stage 1 ductal carcinoma in situ (T1c = 1.3 cm, ER/PR-negative, HER2-positive) underwent bilateral nipple-sparing mastectomy with sentinel lymph node biopsy and V2.5 AeroForm expander reconstruction. The procedure and subsequent postoperative follow-up visits were unremarkable without complications. However, once she entered an magnetic resonance imaging examination room for evaluation of an incidentally found meningioma, the carbon dioxide reservoir valve in both expanders was suddenly activated, releasing filling gas and maximally inflating the device to its 800-mL capacity. She elected to retain the expanders, and they were exchanged for permanent silicone implants 1 month later.

Although the V2.5 AeroForm expander is associated with a much lower rate of overinflation than its predecessor, our case suggests that autoexpansion remains of concern and likely occurs via a different mechanism when the device is subjected to clinical strength magnetic field. Clinicians should not order magnetic resonance imaging scans for women with AeroForm expanders due to the risk of unintended expansion.