Chapter 26. Plastic and Reconstructive Surgery
How does a skin graft survive within the first 24 hours?
A. Capillary network neovascularization
D. Oxygen diffusion from open air
Answer: C. Plasmotic imbibition is how the skin graft survives for the first 24 hours; capillary inosculation occurs in the next 48 hours, followed by neovascularization.
What is the most common reason for free flap failure?
Answer: B. Venous thrombosis is the most common reason for free flap failure; clinical signs of venous thrombosis include congested, blue-appearing flap; capillary refill <2 seconds; eventual loss of Doppler signals; and arterial insufficiency.
What is the perfusion pressure of the capillary network of skin?
Answer: B. Once tissue compression exceeds perfusion pressure, tissue necrosis can occur. Generally, tissues can tolerate ischemia for short periods of time as long as compression is relieved every 1 to 2 hours for 5 to 10 minutes; hence, the reason debilitated patients are turned every 2 hours to prevent pressure sores.
What is the third layer of the epidermis called?
Answer: D. Starting from the outside in, the skin layers are stratum corneum, stratum lucidum (not always present), stratum granulosum, stratum spinosum, and stratum basalis. When measuring the depth of extension for melanoma, the stratum granulosum is used as the starting point of the lesion for Breslow thickness.
What is a local anesthetic that has both anesthetic and vasoconstrictive properties?
Answer: C. Cocaine is the only topical anesthetic that provides ...