Wound
Dermatologic wounds can heal by
second intention, or they can be closed with a variety of methods. Although the
skill and technique of the surgeon are important, so is the choice of wound
closure materials. The purpose of these materials is to maintain wound closure
until a wound is strong enough to withstand daily tensile forces and to enhance
wound healing when the wound is most vulnerable. Understanding the process of
wound healing is important to fully appreciate wound closure.
Healing occurs in 3 stages: inflammation, tissue formation, and matrix formation
and remodeling. The inflammation stage begins within minutes after an injury.
This stage is necessary to establish hemostasis and to begin mobilization of the
immune system. The second stage is the tissue formation stage in which re-epithelialization,
angiogenesis, and fibroblast proliferation and migration predominate. During the
final stage, the extracellular matrix, which is composed of fibronectin,
hyaluronic acid, proteoglycans, and type III collagen, is deposited and
constantly altered with the final accumulation of mature type I collagen. This
stage may take place for as long as 6-12 months after the wound occurs.
Wound strength gradually increases during the healing process. After 2 weeks, a
wound has less than 10% of its final healed strength. By this time, most
superficial or percutaneous closure materials are removed, and the resulting
weak wound has little to rely on for strength unless additional support is
available. Wound strength increases to 20% by 3 weeks and 50% by 4 weeks. At 3-6
months, a wound achieves its maximum strength, which is only 70-80% of its
original strength.