In-Service Exam
Tissue Expansion - 2003





Which of the following has been shown in animal studies to occur following tissue expansion of random-patterned skin flaps?

(A) Decreased collagen content within the flap
(B) Decreased surface area of the flap
(C) Increased elasticity of the flap
(D) Increased likelihood of flap survival
(E) Thickening of the dermis

The correct response is Option D.

Several experimental animal studies have shown increased flap survival following tissue expansion. This increase is similar to that seen with the delay effect and has been shown to occur with both random-patterned and island flaps.

Large bundles of compacted collagen fibrils have been demonstrated within the expanded dermis, and the total collagen content of the flap is increased. Tissue expansion also results in an increase in the total surface area of the flap. However, tensile strength and elasticity are decreased. Histopathologic examination has consistently demonstrated thinning of the dermis, but the stratum spinosum of the epidermis becomes thickened.

References
1. Pasyk KA, Austad ED, McClatchey KB, et al. Electron microscopic evaluation of guinea pig skin and soft tissues "expanded" with a self-inflating silicone implant. Plast Reconstr Surg. 1982;70:37.
2. Sasaki GH, Pang CY. Pathophysiology of skin flaps raised on expanded pigskin. Plast Reconstr Surg. 1984;74:59.
3. Schneider MS, Borkow JE, Cruz IT, et al. The tensiometric properties of expanded guinea pig skin. Plast Reconstr Surg. 1988;81:398.