The osmotic tissue expander is a new device made of a hydrogel expanding skin that does not require external fillings. Once implanted, it absorbs body fluids, which leads to a gradual swelling of the device. The swelling phase is completed in 6 to 8 weeks and results in skin gain. Different shapes and sizes are available, and the devices can be used in almost every area of the body. Over a 4-year period, the osmotic tissue expander was used in 58 patients in different areas of the body. A round osmotic tissue expander was mainly used in breast reconstruction, and a rectangular expander was used for defect coverage after excision (i.e., of scars and tumors). The mean age of the patients was 49.34 years (range, 4 to 76 years). During the expansion phase, the patients noted only a little discomfort and pain for the first few days. Without a silicone membrane in the first-generation expander, the rate of successful explantation and good final result was 81.5 percent. In a few cases, rapid swelling of the device led to the introduction of a silicone membrane that encloses the expander and leads to a slower, more gradual, and consistent swelling. After introduction of the silicone envelope, the success rate improved to 91 percent. The expander is now used with a silicone membrane in every case. The osmotic tissue expander has many advantages compared with the conventional expander: there is no need for painful external fillings and the risk of external infections is avoided. The expander is 10 percent of its final volume and only requires a short incision and a small pocket. An operation can easily be performed under local anesthesia, with minimal tissue mobilization in older children and compliant patients.
From the Department of Plastic Surgery, Kaiserswerther Diakonie, Florence Nightingale Hospital.
Received for publication July 19, 2002; revised October 20, 2003.
Marc A. Ronert, M.D., Department of Plastic Surgery, Kaiserswerther Diakonie, Florence Nightingale Hospital, Kreuzbergstrasse 79, 40489 Duesseldorf, Germany, email@example.com