Monday, June 5, 2023
HomeClinical ProceduresSkin Tissue Expansion

Skin Tissue Expansion


Tissue expansion has become a major reconstructive modality over the past 30 years. It has become more and more widespread, particularly in the fields of breast reconstruction, burn surgery, and pediatric plastic surgery.
In many cases, tissue expansion can be said to have revolutionized plastic surgery.

The lack of available soft tissues is a common challenge facing the reconstructive surgeon. The phenomenon of tissue expansion of the skin and underlying soft tissues has been observed commonly in pregnancy, slow-growing tumors, and fluid collections, where the local tissue expands and enlarges in response to the tension generated by the increased volume of the mass. This response has been found to be a metabolically active process with increased mitotic activity and vascularity of the expanded skin and has been applied clinically as an important skill in the armamentarium of the reconstructive surgeon.

Tissue expansion has numerous advantages. While it provides skin with a near-perfect match in color and texture, minimal donor site morbidity and scarring occur.
It also can be used in various parts of the body to provide tissue with specialized sensory function or adnexal characteristics. Examples include the superior sensation of the skin flaps in breast reconstruction and the hair-bearing flaps designed in the treatment of male pattern baldness developed with expanders.
In addition, expanded flaps are more resistant to bacterial invasion than random cutaneous flaps.
This technique has been extended to other types of tissue, including bladder reconstruction, vascular elongation, and nerve lengthening.

Disadvantages include temporary cosmetic deformity during the expansion phase, prolonged period of expansion, the need for multiple procedures, and complications associated with the implant and placement.


Tissue expansion induces changes in the vascularity and cellular activity in involved skin. Alterations in microcirculation have been shown to create hardier flaps in expanded versus nonexpanded skin. Histologic evidence supports expansion as a type of delay. Cherry and others showed that in the animal model, expanded skin demonstrated increased vascularity on microangiography. These flaps had significantly increased survival length when compared with acutely raised random-pattern flaps.
The capsule that forms around the prosthesis is involved in the increased vascularity and has been shown to have a circulation exceeding that of the subdermal plexus.
Removal of this capsule compromises the integrity of the expanded tissue, so it is often unnecessary and sometimes risky.

Studies of the skin surrounding an expander indicate that the epidermis initially thickens slightly while the dermis demonstrates rapid thinning during the first 3 weeks.
Skeletal muscle atrophies under expansion but retains its activity. However, adipose tissue undergoes permanent atrophy of 30-50% with loss of fat cells.

Increased epidermal mitotic activity demonstrated by Austad and others and increased numbers of radiolabeled keratinocytes suggest that new skin elements form in the expanded flaps. When compared with intraoperative tissue expansion as described by Sasaki, tissue expansion over a period of several weeks attains nearly 4 times the surface area and 3 times the arc of rotation.
Intraoperative expansion depends on the viscoelastic properties of skin in response to load cycling.
This increase in length in response to an applied force is known as “creep” and is distinct from the biological response of the replicating epidermal cells noted in animal model flaps developed over several weeks. Austad and others concluded that this was consistent with a net “dividend” of tissue gained.

- Advertisment -

Most Popular