Chapter 45: Plastic and Reconstructive Surgery
All of the following are true about split-thickness skin grafts EXCEPT
A. Degree of contraction is dependent on amount of dermis in graft.
B. High reliability of take.
C. Healing with abnormal pigmentation more common in thin than thick grafts.
D. Meshing grafts improve their ultimate cosmetic appearance.
Many of the characteristics of a split-thickness graft are determined by the amount of dermis present. Less dermis translates into less primary contraction (the degree to which a graft shrinks in surface area after harvesting and before grafting), more secondary contraction (the degree to which a graft shrinks during healing), and better chance of graft survival. Thin split grafts have low primary contraction, high secondary contraction, and high reliability of graft take, often even in imperfect recipient beds. Thin grafts, however, tend to heal with abnormal pigmentation and poor durability compared with thick split grafts and full-thickness grafts. Split grafts may be meshed to expand the surface area that can be covered. (See Schwartz 10th ed., p. 1832.)
Which of the following definitions is INCORRECT?
A. Flap composition: Description of the tissue components within the flap.
B. Flap contiguity: The position of a flap relative to its recipient bed.
C. Pedicle: Bridge of tissue that remains between a flap and its source; blood vessels that nourish a flap.
D. Free flap: Flaps that are completely detached from the body prior to their reimplantation with microvascular anastomoses.
The composition of a flap describes its tissue components. The contiguity of a flap describes its position related to its source. Distant flaps are transferred from a different anatomic region to the defect. They may remain attached to the source anatomic region (pedicled flaps) or may be transferred as free flaps by microsurgery. These are completely detached from the body, and their blood supply is reinstated by microvascular anastomoses to recipient vessels close to the defect. The term pedicle was originally used to describe a bridge of tissue that remains between a flap and its source, similar to how a peninsula remains attached to its mainland. However, as knowledge of flap blood supply and (micro)vascular anatomy has improved over the years, the term pedicle has increasingly become reserved for describing the blood vessels that nourish the flap. (See Schwartz 10th ed., p. 1833.)
Factors influencing the development of cleft lip/palate include all the following EXCEPT