Later wound repair reorganizes deposited connective tissue, while new vessel formation supports healing and has wider roles in ischemia and tumor growth.
Scar remodeling
•
Remodeling reorganizes deposited connective tissue into a stable fibrous scar.
•
It begins 2–3 weeks after injury and may continue for months or years.
First and second intention
•
Healing by first intention, or primary union, involves epithelial regeneration with minimal scarring, as in well apposed surgical incisions.
•
Healing by second intention, or secondary union, occurs in larger wounds through a combination of regeneration and scarring.
•
The key events in both types of wound healing are identical.
Angiogenesis and its clinical relevance
•
Angiogenesis is the formation of new blood vessels from existing vessels.
•
It is critical for healing at injury sites, development of collateral circulations at sites of ischemia, and tumor growth.
•
Therapies have been developed to augment angiogenesis, for example to improve blood flow to a heart affected by coronary atherosclerosis.
•
Other therapies inhibit angiogenesis to impede tumor growth or block pathological vessel growth, as in wet macular degeneration of the eye.