Flaps

Question 1

What is the primary defect in relation to flaps?

Answer 1

It is the operative wound bed that requires repair

Question 2

In terms of a flap, what is the secondary defect?

Answer 2

The secondary defect is the operative wound created by the flap elevation and closure of the primary defect

Question 3

What is the primary tension vector of a flap?

Answer 3

Direction of the force resisting the movement of the flap body

Question 4

What is the secondary tension vector?

Answer 4

Direction of force created by closure of donor site defect

Question 5

What is the pivot point of a flap and what is critical to do in this area?

Answer 5

The point on the base of the flap that the flap will rotate around, critical to undermine around this area!

Question 6

What is a “key stitch”?

Answer 6

The important first stitch that moves the flap onto the primary defect (can be between the edge or top of the flap in an advancement flap or the secondary defect on a rotational/transpositional flap (helps it stay in place)

Question 7

What is an axial flap?

Answer 7

These are flaps that use a named vessel as their primary blood source

Question 8

What are the most common axial flaps used in dermatology?

Answer 8

Paramedian forehead flap, dorsal nasal rotation “Rieger” flap, and theh Abbe cross-lip flap

Question 9

What vessel supplies the paramedian forehead flap?

Answer 9

Supratrochlear artery

Question 10

What is the vessel that supplies the dorsal nasal rotation “Rieger” flap?

Answer 10

Angular artery

Question 11

What is the vessel that supplies the Abbe cross-lip flap?

Answer 11

The labial artery

Question 12

What is a random pattern flap?

Answer 12

This is a flap that gets its blood supply from unnamed musculocutaneous vessels within the pedicle

The elevated portion of the flap is fed by the anastomotic subdermal and dermal vascular plexuses

Question 13

Do advancement flaps alter the primary tension vector?

Answer 13

NO, they just redistribute tissue

Question 14

What is the goal of an advancement flap?

Answer 14

To redistribute Burow’s triangle(s) away from free margins or to improve function/cosmetic outcomes

Question 15

How does a rotation flap affect the primary tension vector?

Answer 15

Rotation flaps, unlike advancement flaps, DO redirect primary tension vectors along an arc adjacent to the primary surgical defect

Question 16

Do advancement flaps or rotation flaps cause secondary defects?

Answer 16

Advancement flaps do not create secondary defects, rotation flaps do however

Question 17

How tall and long must a rotation flap be relative to the primary defect?

Answer 17

Must be taller and longer, because the flap loses height and length when it is rotated

Question 18

Where are the most common areas to use a rotation flap?

Answer 18

Large defects on the medial cheek, large defects on the scalp, and areas with curved skin tension lines like the chin and mental crease

For free margin protection: lower eyelid, nasal tip, and upper lip

Question 19

Where is the tension vector on for transposition and interpolation flaps?

Answer 19

Transfers the tension from the primary defect to the donor site (goal to use a nearby but “nonadjacent” tissue reservoir)

Question 20

What are some disadvantages of a single-stage transposition flap/

Answer 20

Pincushioning/”trapdooring”

There needs to be extensive/wide undermining to prevent this

Question 21

What is the maximum length: width ratio for most flaps?

Answer 21

4:1

Question 22

What transposition flap allows for a larger length to width ratio flap and why?

Answer 22

Interpolation (two-stage transposition) because they maintain a thick vascular pedicle that can be random or axial pattern

Question 23

How long is a two-stage transposition pedicle kept in place before separating?

Answer 23

Usually 3 weeks

Question 24

What are the main uses for the interpolation/two-stage transposition flap?

Answer 24

Large defects on the nose, large helical rim defects, and large lip defects

Question 25

What flaps utilize a key switch for the secondary defect first?

Answer 25

Rhombic flab, bilobed transposition flaps

Question 26

How can you tell a rhombic flap from its final suture line?

Answer 26

It looks like a question mark

Question 27

How is a bilobed transposition flap designed?

Answer 27

Starting from the midpoint of the defect at a 45 degree angle you start the first donor site, the second one is 45 degrees from that primary defect filler, then a standing cone is taken from there (or you can have more lobes if needed). The overall angle is 90 degrees

Question 28

In what order do you close a bilobed transposition flap?

Answer 28

Tertiary defect (secondary lobe donor site), key stitch goes to secondary defect (primary lobe donor site), which goes to primary defect closed last

Question 29

What things can cause “pincushioning” on the bilobed flap?

Answer 29

Oversized flap, insufficient undermining, increased bulkiness on the underside of the flap, flap lymphedema, peripheral contraction, and insufficient tacking of flap to wound base

Question 30

What is the primary use of a Z-plasty?

Answer 30

Lengthening a contracted scar and redirecting tension

Question 31

How does the angle size of a z-plasty affect the flap?

Answer 31

Increased angle size leads to increased length gain and increased reorientation

Question 32

What determines the maximum length of the paramedian forehead flap?

Answer 32

Distance between the orbital rim and the frontal hairline

Question 33

What happens if a paramedian forehead flap goes beyond the hairline?

Answer 33

The tip will have terminal hair that will end up transposed onto the tip of the nose

Question 34

What is the ideal pedicle width for a paramedian forehead flap?

Answer 34

1-1.5cm

Question 35

What can happen if the pedicle of the paramedian forehead flap is too wide or too narrow?

Answer 35

Too wide: kinks the artery leading to tip necrosis potentially

Too narrow: fails to incorporate artery and there will be ischemia

Question 36

When should an Abbe lip switch flap be used?

Answer 36

Large (greater than 1/3 the lower lip), full-thickness

Question 37

What is the primary use of a nasolabial/melolabial interpolation flap?

Answer 37

Nasal ala (number one use) can also be used for large lesions of the upper lip

Question 38

What is the main advantage of the nasolabial/melolabial interpolation flap over a single-stage transposition for the ala?

Answer 38

It doesn’t blunt the alar crease

Question 39

What is the retroauricular (“book”) flap?

Answer 39

Random pattern flap that comes from a rectangular shaped flap from the retro auricular sulcus to the hairline and then the flap tip is thinned and suture onto the helix… pedicle is divided 3 weeks later

Question 40

What is the most common use of the retro auricular (“book”) flap?

Answer 40

Addressing large helical rim defects, with or without a loss of the cartilage

Question 41

Where is the primary tension vector for a classic rhombic flap?

Answer 41

Direction and magnitude of tension vector is established from the closure of the donor site

Question 42

What is the difference in SCC risk between clinical and incidental perineural invasion?

Answer 42

Clinical perineural invasion was more likely to recur locally and have earlier disease-specific death compared to those with incidentally found perineural invasion

Question 43

What should be done if a pt who had a large flap done returns to the clinic 24 hrs later w/swelling and pain with hematoma?

Answer 43

take down the flap, control bleeding sources, and can consider the placement of a drain

acute postoperative hematomas that are expanding connote active bleeding that has to be controlled. Especially important with flaps where this can compromise flap integrity