Fundamentals of Tissue Expansion

Tissue expansion is a reliable method to obtain additional tissue, preserving its sensitivity and heir-bearing qualities and, most importantly, minimizing its donor defect. There are several histological changes in tissues undergoing tissue expansion, including thickening of the epidermis and thinning of the dermis and fat. There are many forms of expanders, and each has specific indications as well as different percentages of tissue gain. Ideally, tissue expanders should be placed in an avascular plane (usually above the fascia), and the incision should be aligned perpendicular to the long axis of the expander to minimize stress on the incision during the expansion process. The filling of the expander starts with 10–20% of its total capacity at the time of placing it, and the rest is progressive in a range of one to three times a week. The expanders are removed approximately 2 weeks after the desired tissue expansion has been obtained, and it is extremely important to avoid capsulectomy of the flap because it can compromise the vascularization of the skin. Surgical site infection is the most frequent complication followed by exposure of the tissue expander.