78 Subdermal plex flaps

Question 1

delayed phenomenon as it enhances tissue perfusion

Answer 1

initially perfusion will decrease after elevating and apposing an intended flap (decreases 10-40%)in 3 weeks perfusion is actually increased to 120-150% of normalfactors: alteration of sympathetic tone, dilation of chock vessels, reorientation of vessels, changes in tissue metabolism and neovascularization

Question 2

difference btwn angiogenesis and vasculogenesis

Answer 2

angiogenesis–growth of micro vessels from existing capillary bedvasculogenesis–development of new vessels in situ from bone marrow derived endothelial progenitor cells

Question 3

guideline for length of advancement flap

Answer 3

should be as long or preferably longer than the length of the wound to closea relaxing incision parallel to the wound should be as long as the wound or 1.5 x the length of the wound

Question 4

guideline for width of advancement flap

Answer 4

should not be too narrowavoid converging incisions (wider tip than base)create wide base that is slightly wider than the overall width of the flap

Question 5

types of sub dermal plexus flaps

Answer 5

LOCAL (adjacent to wound bed)1. advancement flap–single or bipedicle2. rotation flap–skin fold flaps3. transposition flap4. interpolation flap5. plasty (H, Z, V-Y)6. composite flaps (incorporate underlying structures)DISTANT 1. direct distant (pouch or hinge)2. Indirect distant (delayed transfer of a tube flap)

Question 6

types and difference of rotating flaps

Answer 6

rotating flaps all pivot around a point and include1. rotation flaps–semicircular incision away from pivot point2. transposition flaps–share a common border with defect3. interpolation flaps—lack border with defect and need a bridging incision or tubed

Question 7

types of advancement flaps

Answer 7

1. single pedicle (two incisions perpendicular to wound)2. bipedicle (one incision parallel to wound)rely on inherent elasticity of local skin to stretch over the defect

Question 8

what is an H plasty

Answer 8

two single pedicle flaps from opposing directionbenefit is that flap length is reduced to maintain blood supply

Question 9

main disadvantage of an advancement flap

Answer 9

bc it relies on the skins inherent elasticity that main disadvantage is that elastic RETRACTION and innate tension will be transmitted across the wound

Question 10

skin fold flaps

Answer 10

subdermal plexus flap (elbow and flank fold common)rotation flapmust preserve one of any four attachments for adequate blood supplyattached dorsal and ventral trunk; medial and lateral upper limbin close proximity of lateral thoracic artery (elbow) and deep circumflex iliac artery (flank)

Question 11

scrotal flap

Answer 11

subdermal plexus flap advancement flapharvest post neutermaintain plexus on the side opposite of the wound defectincise tunica dartos to enable scrotum to expandclose inguinal and perineal defects

Question 12

preputial reconstruction

Answer 12

subdermal plexus flapadvancement flap–bipedicle with buccal mucosa

Question 13

phalangeal fillet

Answer 13

subdermal plexus flaptransposition flapdigit amputation (digit 1) removing bone but maintaining skin, digital pad and blood supply

Question 14

labial flaps

Answer 14

subdermal plexus flapcomposite/advancement flaprich blood supply from inferior and superior labial arteriesincision parallel to lip margin, full thicknesscheck that commissure is not too tight

Question 15

lip to lid flap

Answer 15

subdermal plexus flapcomposite (mucocutaneous)/interpolation flap (needs bridging incision)close proximity of angularis oris artery

Question 16

complications of sub dermal plexus flap

Answer 16

1. infection2. dehiscence3. seroma4. necrosis

Question 17

causes of dehiscence in sub dermal plexus flaps

Answer 17

infectiontensionsurgical trauma (keep moist, minimal manipulation)flap necrosis poor blood supply (previous surgical attempts)

Question 18

ways to prevent seroma

Answer 18

closed suction drainssoft compressive bandagerestrict vigorous exercise

Question 19

morbidity associated with sub dermal plexus flaps before or after radiation therapy

Answer 19

HIGH (higher if radiation before because destroys fibroblasts and blood supply)62% dehisce35% necrosis27% infection

Question 20

why does flap necrosis occur

Answer 20

when metabolic requirements of the skin exceed the capacity of sub dermal plexus perfusion–insufficient # of vessels–damage to blood supply during manipulation–thrombosis–decreased perfusion/oxygenation–self trauma–bandagesusually apparent within 2-3 days post op

Question 21

two options for devitalized skin

Answer 21

-liquefactive necrosis-eschar (scab) may not separate from underlying tissues for up to 4 weeks

Question 22

option to improve survival of flaps with marginal vascularity

Answer 22

hyperbaric oxygen therapyhyper oxygenated blood may stimulate fibroblasts and enhance revascularization

Question 23

staging procedures to increase blood supply (delay phenomenon) should be delayed how long

Answer 23

~ 3 weeks

Question 24

three methods to move tubed pedicle flap

Answer 24

1. caterpillaring (doubling up on itself)2. waltzing (lateral alternating)3. tumbling (direct advancement–most common)