Chapter 26: Plastic and Reconstructive Surgery

Chapter 26. Plastic and Reconstructive Surgery

How does a skin graft survive within the first 24 hours?

A. Capillary network neovascularization

B. Neovascularization

C. Imbibition

D. Oxygen diffusion from open air

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?

A. Arterial thrombosis

B. Venous thrombosis

C. Capillary thrombosis

D. Arterial embolus

Venous thrombosis is the most common reason for free flap failure; clinical signs of venous thrombosis include congested blue appearing flap, cap refill <2 seconds, eventual loss of Doppler signals, and arterial insufficiency.

What is the perfusion pressure of the capillary network of skin?

A. 10 mm Hg

B. 15 mm Hg

C. 30 mm Hg

D. 50 mm Hg

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 Q2 hours to prevent pressure sores.

What is the third layer of the epidermis called?

A. Stratum basalis

B. Stratum spinosum

C. Stratum lucidum

D. Stratum granulosum

Starting from outside to in, the skin layers are stratum corneum, stratum lucidum (not always present), stratum granulosum, stratum spinosum, and stratum basalis. When measuring 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?

A. Lidocaine

B. Bupivacaine

C. Cocaine

D. Novacaine

Cocaine is the only topical anesthetic that provides both an anesthetic and vasoconstrictive effect. It is often used in nasal surgery because of the added bonus of vasoconstriction in an extremely vascular area.