A 48-year-old woman comes to the office 10 days after undergoing breast reduction surgery. She feels well overall and is taking acetaminophen as needed for pain control. Vital signs are normal. Examination of the breasts reveals intact surgical incisions without drainage; the incisions are pink, shiny, and slightly warm. The surrounding skin has mild edema but no erythema. Which of the following wound healing processes is most likely occurring at this time?

Question

A 48-year-old woman comes to the office 10 days after undergoing breast reduction surgery.  She feels well overall and is taking acetaminophen as needed for pain control.  Vital signs are normal.  Examination of the breasts reveals intact surgical incisions without drainage; the incisions are pink, shiny, and slightly warm.  The surrounding skin has mild edema but no erythema.  Which of the following wound healing processes is most likely occurring at this time?

Quizplus · Accepted Answer

11ec160b_3907_3e77_9249_2dd28c35b569_MD0001_00 Ten days after surgery, this patient's intact, healing surgical incisions are most likely undergoing a type of neovascularization called angiogenesis, the process by which new blood vessels sprout and grow into the wound from surrounding, uninjured vessels. Angiogenesis primarily occurs during the proliferation phase of wound healing, which begins around day 3 (overlapping with the end of the inflammatory phase) and lasts approximately 5 weeks. During the proliferation phase, fibroblasts multiply and synthesize ground substance and type III collagen, which form an amorphous gel into which new capillaries can grow. In addition, fibroblasts secrete fibroblast growth factor and vascular endothelial growth factor, which stimulate endothelial cell proliferation, migration, and differentiation-leading to the formation of new capillaries. By increasing the number of capillaries within the healing surgical incision, angiogenesis increases blood flow to the area, causing the pink and slightly warm characteristics of the wound at this stage. The incision's newly formed epithelium (ie, reepithelialization) typically has a shiny appearance as well. (Choices A and C) Degranulation of mast cells and infiltration of polymorphonuclear leukocytes occur during the inflammation phase, which starts within hours of the injury and lasts approximately 5 days. During this phase, there is often moderate edema, redness, and/or warmth of the wound and nearby soft tissues due to high levels of inflammatory mediators (eg, IL-1, TNF-alpha). In contrast, this patient's wound is 10 days out from surgery and most likely in the proliferation phase. (Choice B) Extensive collagen crosslinking, which increases the tensile strength of the wound, occurs during the final phase of wound healing, maturation. Maturation typically occurs between 3 weeks and 1-2 years (not 10 days post-surgery). (Choice E) Collagen synthesis begins during the proliferation phase, along with angiogenesis. However, fibroblasts predominantly synthesize type III collagen; type III collagen is then replaced with type I collagen during the maturation phase. Type II collagen is primarily found in articular and hyaline cartilage rather than the skin. Educational objective: Angiogenesis is the process by which new blood vessels are formed. It primarily occurs during the proliferation phase of wound healing and is stimulated by growth factors such as fibroblast growth factor and vascular endothelial growth factor. __________ References: Angiogenesis. (http://www.ncbi.nlm.nih.gov/pubmed/21807843) Molecular mechanisms and clinical applications of angiogenesis. (http://www.ncbi.nlm.nih.gov/pubmed/21593862)

A 48-Year-Old Woman Comes to the Office 10 Days After