Tissue expansion
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Skin_expander.jpg
Tissue expansion is a technique used by plastic and restorative surgeons to cause the body to grow additional skin, bone or other tissues.
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Skin expansion
Keeping living tissues under tension causes new cells to form and the amount of tissue to increase. In some cases, this may be accomplished by the implantation of inflatable balloons under the skin (see figure). By far the most common method, the surgeon inserts the balloon expander beneath the skin and periodically, over weeks or months, injects a saline solution to slowly expand the overlaying skin. The growth of tissue is permanent.1. Breast reconstruction surgery, for example, can use this technique when the mammary gland was removed by surgery (radical mastectomy). Later a more permanent artificial implant (silicone breast implant is inserted under the expanded pouch of skin.
In other applications, excess skin is grown purposefully by expansion on the back or the buttocks, so that it can be harvested later for transplantation to another site where skin was lost due to trauma, extensive wounds, surgery, burns, etc. A device called a dermatome is used to slice thin strips of skin from the expanded area, which later is closed by suturing it.
Tissue_expander_diagram.jpg
Tissue expansion has also been used for the technique of penile foreskin restoration, which is usually non-surgical and applies tension externally using specialized devices to replace circumcised tissues.
Bone expansion
Bone is another tissue that can be expanded relatively easily, by using external devices which are slowly separated using mechanical contraptions, so that bone grows in response to elongation (bone distractor). Other techniques and external devices have been studied and have shown some success, such as in the fitbone surgery.3 This technique was pioneered in 1951 by the Russian physician Ilizarov, and is called the Ilizarov apparatus. It is capable of lengthening limbs in cases of pathological loss of bone, asymmetry of limbs, dwarfism, short stature, etc. In reconstructive and cosmetic surgery, bone expanders have been used to elongate the mandibula in cases of congenital disorders, trauma, tumors, etc. Other newer devices such as the orthofix and intramedullary skeletal kinetic distractor (ISKD) are also used for limb lengthening. It can add over 6 inches to per bone, but is expensive, painful, and time-consuming (each procedure lasts around 8-12 months).
References
1. Neumann CG. The expansion of an area of skin by the progressive distension of a subcutaneous balloon. Plastic Reconstructive Surgery 1957;19:124-30.
2. Radovan C. Tissue expansion in soft-tissue reconstruction (http://www.cirp.org/library/restoration/radovan1/). Plast Reconstr Surg 1984;74(4):482-92.
3. External tissue expansion successfully achieved using negative pressure (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14745629&dopt=Abstract) Zagazig University, Zagazig City, Sharkia, Egypt 2004
External links
- Ilizarov apparatus (http://www.vardaan.net/ilizarov.htm).
- About Faces: Skin (http://www2.nidcr.nih.gov/iyf/skin.html). NICDR National Institutes of Health on-line exhibit. Source of the images used.