Like with pregnancy where over a period of months (9 months in the case of pregnancy, much shorter when performed as balloon tissue expansion), the body’s skin has a special ability to grow in response to being stretched. Balloon tissue expansion takes advantage of this characteristic, allowing the body’s skin to actually grow, a phenomenon scientifically called biologic creep. In the scalp, this can be very useful in cases particularly with scarring, where the surrounding non-scarred normal scalp can be stretched to as much as three to four times its original size, permitting the removal of large amounts of the scarring.
Tissue expansion is a challenging procedure that should only be done by a physician experienced in the technique. This is most commonly a facial plastic or plastic surgeon who has been trained in more advanced surgical techniques that assure a low rate of complications and a successful outcome. The procedure itself involves two surgical procedures over a two to three month period. In the first procedure, one or more (depending on the surgical plan and the size of the defect) balloon tissue expanders are inserted under the normal scalp skin- this is the scalp that will be expanded to two to three times its size. This first procedure, performed either under oral or twilight sedation (can be done under general anesthesia if desired in particular for young children), depending on the surgeon’s and patient’s preferences, takes 90 minutes to perform then requires a few days for recovery. Small tube(s), one for each expander, will emerge from the side of the scalp, connecting the expander under the scalp to the inflation port into which the saline will be injected.
Two weeks after the first procedure, the inflation of the balloons begins. Two to three times a week, saline is injected into the expander(s), performed either at the surgeon’s office or by the patient or a family member. This is a slow gradual process, with 10 to as much as 30cc injected into each expander each time, to the point of notable tightness of the overlying skin and/or the patient experiencing pronounced discomfort. The inflation process proceeds until the desired amount of additional skin has been generated, a process that can take as little as four weeks to as long as 12 weeks, depending on how fast the expansion process proceeds and how much additional tissue is needed.
The second surgery similarly is performed under oral sedation or twilight or general anesthesia. During this procedure, the balloon(s) is/are removed, most if not all of the scarred skin is excised, with the expanded skin used to cover over the defects. The result is the normal hair bearing scalp skin replacing the scar tissue. Recovery after this second procedure takes around one week, at which time sutures are removed. The occasional patient benefits from hair grafting to any residual scars at four months or later – this grafting allows transplanted hairs to grow through these scars.
In order to be a good candidate for tissue expansion, the patient must be relatively healthy, ideally a non-smoker, with the scalp having not had any prior radiation or extensive surgery (including hair transplants in certain cases) to assure that plenty of blood supply is available to the scalp that will be expanded. Most importantly, however, the patient must be highly motivated, for during the expansion process the scalp will eventually be stretched to a point where it is cosmetically quite noticeable. Oftentimes, students will do this during a two plus month summer break, or adults will take a prolonged vacation.