In the past, plastic surgery was used to repair skin scars, moles and hemangiomas. It mainly relies on autologous tissue transplantation, so some people call plastic surgery "robbing Peter to pay Paul". Sometimes for smaller skin scars, one-time excision or suture can be used, although the surgical effect is ideal; But skin grafting can only be used for slightly larger scars, especially those on the face and head. Although skin grafting can improve the appearance of scars, due to a series of problems such as skin color and skin edge scars after skin grafting, even if skin grafting survives, it will not bring much change to facial beauty. The plastic principle of tissue expander is that it can provide "extra" skin and soft tissue. This dilator is a capsule made of silicone rubber film. When in use, it is implanted under the skin or muscle layer by surgery, and sterile isotonic saline is injected into the injection pot regularly through the skin to expand the tissue. After a certain period of expansion, the skin and soft tissue on the surface of the expansion bag will gradually expand, providing more than 50% of "redundant" skin tissue. Tissue expansion is mainly suitable for face, neck, head, chest, trunk, limbs and other parts that need normal skin for cosmetic plastic repair. The advantage is that the "extra" skin tissue provided by this tissue expansion is similar or consistent with the skin around the defect area in terms of color, texture, thickness, hair distribution and aesthetic degree, and also has the characteristics of good blood supply and feeling. Organizational expansion is usually carried out in two stages. The main operation is dilator implantation. Puncture the skin regularly after removing stitches, and inject sterile saline through the injection pot. 65438+ 0-2 times a week, and the required expansion time is generally 3-6 months. The expanded skin area should be twice that of the defect to repair the defect and close the donor site wound. After the skin expansion meets the expected requirements, the second operation can be carried out, that is, the tissue expander is taken out through the original incision, the scar or diseased tissue in the defect area is removed, and the expanded skin is pushed or rotated to the defect area, and the whole process is completed after the plastic suture operation. The following picture shows a case of waist nevus. A dilator was implanted on the normal skin around the nevus and water was injected. In the second stage, the dilator was taken out, the nevus was completely removed and the incision was sutured.