The Beginning of a New Era in Tissue Expansion: Self-Filling Osmotic Tissue Expander???Four-Year Clinical Experience

Abstract

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.

Synthesis and properties of a novel anisotropic self-inflating hydrogel tissue expander

“…In parallel, Wiese and co-workers conducted research into poly(methyl methacrylate) (PMMA)-based hydrogels, which had an increased swelling ratio [13,15,16]. Further clinical applications were reported by Berge et al [17], who facilitated direct closure of a radial forearm flap donor defect, and by Ronert et al [18,19], who used the device for breast reconstruction after mastectomy and achieved coverage of a post-auricular defect following the excision of a large pigmented nevus. In 2007 Kobus published a preliminary report using selfinflating tissue expanders in two-stage cleft palate repair [20].…”

Acrylamide, Acrylic Acid and N-Isopropylacrylamide Hydrogels as Osmotic Tissue Expanders

“…As the periods of increase alternate with periods of decrease or stagnation, the affected tissue is provided with the possibility of recovery and functional normalization before further expansion. The swelling phase of other osmotic tissue expanders is completed in 6-8 weeks [16] , if they are used with a silicone membrane. Our new devices were tested without a silicone membrane.…”

“…The self-filling tissue expanders cause only relatively slight discomfort and pain in the first few days. Moreover, they can be applied in different sizes and shapes in almost every area of the body [16] . Hydrogels produced by the use of AAm, AAc and NIPAAm polymers are extensively used in various biomedical areas [17][18][19][20][21] .…”

Autoinflation of Saline-Filled Inflatable Breast Implants

“…Near-isotonic implants, at full inflation, expanded much more slowly. A German study, by Ronert et al (22), has taken this concept further. They have developed an 'osmotic tissue expander', which contains hydrogel.…”