If you gradually expand skin over a period of time, the pressure exerted on the skin actually stimultaes new tissue to grow. The most common example of this is pregnancy, when the abdominal skin grows to accomodate the enlarging baby. This same concept can be applied to treat bald areas of the scalp.
There are currently 2 methods of Scalp Expansion :
The expansion and excision of bald scalp creates the conditions for subsequent approximation of hair-bearing scalp to cover the area of bald scalp excision. The man most likely to benefit from bald scalp excision and hair-bearing scalp advancement is one who :
Although hair transplantation is by far the most commonly performed type of surgical hair restoration procedure, some patients may be candidates for scalp reduction or scalp flaps. Some surgeons advocate the use of these procedures in some patients, and the procedures may be choices recommended by a surgeon in selected patients. The scalp reduction of scalp flap procedures can be performed with or without scalp expansion.
The basic principles of volumetric scalp expansion are :
A tissue expander is a balloon that is placed beneath the scalp. Over a period of weeks or months, saline (salt water) is gradually added to the balloon to slowly inflate it. As the balloon is inflated, it puts tension on the skin. Within a few days, the scalp seems to relax as new skin grows in response to the tension. Once the scalp is lax again, more fluid is added and the process is repeated until enough hair-bearing scalp is present to cover the desired area.
An implantable balloon-type scalp skin expander was first used for medical purposes about 25 years ago to facilitate surgical removal of a tattoo. By the early 1980s the technique of tissue expansion and bald scalp excision was being pioneered at Hershey (Pennsylvania) Medical Center for treatment of massive scalp defects in children. By the mid-1980s the technique was being used by physician hair restoration specialists to treat selected patients with male-pattern hair loss.
Volumetric scalp expansion begins with the insertion of a Silastic (non tissue reactive) envelope beneath the scalp. The envelope is inserted into the subgaleal plane, a space of loose tissue between the overlying scalp and the blood vessel-rich tissue underneath. The subgaleal space is nearly devoid of blood vessels, so insertion of the envelope causes little bleeding and does not compromise blood or nerve supply to the scalp. As a rule, envelopes are inserted on right and left sides of the head to fit the distribution of bald scalp.
About two weeks after insertion of the device(s), a small amount of saline fluid is injected into the envelope(s) through self-sealing ports to begin inflation of the devices and to begin the process of scalp expansion. Injections of saline are repeated at intervals over succeeding weeks and the scalp responds by expanding. If there are scalp expanders on opposite sides of the head they may be injected in alternate weeks.
Volumetric scalp expansion causes a visible change in head shape as the device(s) inflate. After the expander (or expanders) are placed in the first operation, you will begin the expansion phase. During this stage, your head will begin to look more and more distorted as the expanders are inflated. Friends and relatives can be prepared for this temporary change. Strangers may be less prepared. It will likely be necessary to wear a hat to conceal your oddly-shaped head. A good relationship between patient and physician hair restoration specialist can prepare the patient for managing any psychological, emotional or social problems that may arise during the temporary period of scalp expansion.
When scalp expansion is judged to be satisfactory the devices are drained and removed. The patient is taken to an operating room for:
Individual patients may require follow-up treatment such as “fill-in” hair transplantation and use of hair restoration pharmaceuticals (minoxidil or finasteride) to achieve the maximum cosmetic improvement. “Fill-in” hair transplantation may be made more difficult and costly by scalp expansion and excision, however; bald scalp excision and hair-bearing scalp approximation may reduce the number of donor follicles that can be harvested in a single transplantation session, thus increasing the time and dollar investment of “fill-in” hair transplantation.
Patients can usually shower and shampoo the day after surgery, not waiting until sutures are removed. Healing takes place over the following two to six weeks. Postoperative bleeding and infection are potential complications of volumetric scalp expansion and bald scalp excision. Sometimes a postoperative scar forms at the site of hairline suturing. A scar can be revised later to make it inapparent, but revision is more technically difficult when the scar is a so-called “slot defect” that forms where two previously non-adjacent areas of scalp are sutured together
recovery – After scalp expanison surgery, you will have prescriptions for antibiotics to prevent infection and pain pills to control discomfort. Many patients do fine with acetaminophen (Tylenol) after surgery and do not require stronger medication.
risks – Scalp expansion surgery can result in infection, scarring, or rarely, insufficient blood supply during the expansion phase that leads to loss of part of the flap.
results – Once the new hair-bearing scalps is in place, it will continue to remain just as if it were in its original site. Scalp expansion surgery does not stop hair loss, and you will continue to lose hair just as you would have if you had not had the scalp expansion surgery, but usually the effects will last 10 to 20 years or more.
The most obvious drawback of scalp expansion surgery is the period of weeks or months in which the balloons are inflated and your head takes on an oddly-shaped appearance. For this reason, scalp expansion surgery is nowadays very uncommon.
Nonvolumetric scalp expansion is accomplished with a physical device. Expansion may be over a period to time (one to three months) using a stretchable band implanted in the subgaleal space under constant tension. Scalp expansion may also be accomplished during a scalp reduction procedure using a skin-stretching device.
Scalp extension allows scalp reduction to be performed with much greater effect and allows previously determined non-candidates to have successful scalp reductions. Basically, it involves the use of a surgical device, made of two rows of hooks connected by broad-based elastic bands, that is placed on the undersurface of the scalp during the first scalp reduction. Over a one-month period, elastic recoil causes a constant, gentle upward pull of the hair-bearing tissues, thereby loosening and stretching the scalp. This allows for another, and usually greater, scalp reduction to be done. The scalp extension process can be repeated.
With scalp extension, the complete series of scalp reductions can be done within a 30- to 90-day period. In the past, some scalps could not be reduced at all and those that could be reduced often took as long as 1 1/2 years for the procedures to be completed.
Scalp extension has some of the benefits of scalp expansion, although the amount of tissue stretch is less. Its great advantages are that it causes little or no discomfort and deformity. It is a relatively simple procedure, thereby adding little time and difficulty to the scalp reduction operation.
Advantagescited for the implanted nonvolumetric scalp expander include:
Potential complications and side effects of nonvolumetric scalp expansion include: