Tissue expansion is a technique to induce the body to grow more skin, bone or other tissues which can be used on any part of the body. The devices that are used to make the tissues expand are called tissue expanders. They are silastic balloons which shape depends on the site of the expansion and the reconstruction needed. Generally these balloons are rounded, rectangular or crescent shaped. Rectangular ones have been proven to be the most effective ones as they have a larger surface area as compared to round or crescent ones.
Tissue expanders are generally used for breast reconstruction following the removal of breast or to repair skin damaged by burns, accidents, surgery or any birth defect. Sometimes they are used in cosmetic surgery as well. Expanders are available in different sizes. An expander is introduced below the skin and gradually filled with saline water so that when it expands the skin also will expand. The best example of tissue expander is a fetus, which is in the uterus of the mother. As the fetus grows, the uterus expands slowly to allow the fetus to grow further. Tissue expanders also work on the same principle. They blow up slowly causing the skin or any tissue to expand to the desired amount.
There are different kinds of tissue expanders. One expander has a distant filing valve where the injection site that receives the needle during the inflation is attached by a stem to the expander. This is the most common one to be used. The second design available is one in which the expander and the injection port are a single comprehensive unit. It has a self-sealing membrane and is lined with metal or a tick polymer to avoid accidental puncture during injection of saline. A third type of tissue expander obtains more expansions at one end than the other by using different methods. These expanders are generally used in breast reconstruction to get a more normal looking breast. This type of an expander has also been advocated in treating male baldness.
The fourth one is of an experimental nature. It is a self inflating expander consisting of a semi permeable membrane that surround a substance like sodium chloride or salt which is present in adequate concentrations to create osmosis. By this method there is exchange of fluids and saline is formed in the expander, making it expand to the desired amount. |
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