Skin flaps

Question 1

How is circulation supplied to the skin?

Answer 1

Segmental aa supply from simple and mixed cutaneous aa

—> run through/between mm and arborize in 3 plexuses that run parallel to skin surfaces

• SQ (deep)
• cutaneous (middle)
• subpapillary (superficial)

Question 2

What is a subdermal plexus flap?

Answer 2

Full thickness “tongue” of skin

Detached from surrounding skin along 3 of 4 quadrants

Question 3

What does flap survival rely on?

Answer 3

Remaining collateral circulate from the remaining cutaneous attachment and its vasculature which is the subdermal plexus (SDP)

Question 4

How long should your subdermal plexus flap be?

Answer 4

At least as long as the wound —> 1.5x length

Question 5

What are the pivotal flap types??

Answer 5

Rotation -have a curvileanear configuration

Transposition - linear axis (3:1 flap length: width)

Interpolation -linear but base is located at a distance from the defect

Question 6

What are the types of advancement flaps??

Answer 6

Single pedicle
Bipedicle or H-pasty

V-Y plasty

Question 7

What is pantographic expansion??

Answer 7

When you cut broader at the base, you get extra length/ tension relief in your skin flap

Question 8

The effective length of a pivotal flap moving through an arc of 180 degrees is reduced by ____%

Answer 8

40

Question 9

What type of skin flap is commonly used for defects at the elbow or on the flank?

Answer 9

Transposition flap

—> elbow fold flap and flank fold flap

Question 10

What type of flap has a pedicle away from the defect that must pass over or under intervening tissue?

Answer 10

Interpolation flap

Question 11

What type of flap is used for full thickness circumferential wounds to distal limbs??

Answer 11

Distant flap/pouch flap

Question 12

What are complications of subdermal plexus flaps???

Answer 12

Infection 
Seroma 
Desensitization and self trauma 
Skin edge dehiscence 
Global flap necrosis

Question 13

How can you avoid infection when doing a subdermal plexus flap??

Answer 13

Don’t do flap until recipient bed has healthy granulation tissue

Aseptic technique

Question 14

What can lead to skin edge dehiscence ?

Answer 14

Excessive tension
Infection
Seroma
Pre-existing dz (DM/Cushing/Radiaiton)

Question 15

What can lead to global flap necrosis??

Answer 15

Compromise of blood supply

• > iatrogenic (most common)
• > thrombosis
• > self-trauma

Question 16

What type of flap relies on a direct cutaneous artery and vein at the base of the flap?

Answer 16

Axial pattern

Question 17

What benifit do axial pattern flaps have over subdermal plexus flaps??

Answer 17

Have better perfusion

Question 18

What is an island arterial flap?

Answer 18

Modified axial pattern flap where the entire cutaneous pedicle is severed but the direct cutaneous artery and vein is preserved

—> have potential to use as a free flap for transfer and microvascular anastomoses

Question 19

When are axial pattern flaps most commonly used?

Answer 19

Wound closure after tumor resection or trauma

Question 20

How does the survival rate of axial pattern flaps compare to sub-dermal plexus flaps ?

Answer 20

Axial pattern flaps survival rate is 2x that for subdermal plexus flaps

Question 21

What are the axial pattern flaps that can be used in a dog?

Answer 21

Caudal auricular 
Omocervical 
Thoracodorsal 
Caudal superficial epigastric 
Lateral genicular 
Deep circumflex iliac 
Lateral caudal 
Superficial brachial 
Superficial temporal

Question 22

What axial pattern flaps can be used in cats?

Answer 22

Caudal auricular
Thoracodorsal
Caudal superficial epigastric
Superficial temporal

Question 23

What are the landmarks for the caudal superficial epigastric APF?

Answer 23

Medial - midline of abdomen

Lateral - parallel to medial at equal distance from teats

Length - variable, can include last 4 glads

Question 24

What type of APF can be used for repair of caudal abdominal, inguinal, preputial perineal thigh, and stifle defects??

Answer 24

Caudal superficial epigastric

Question 25

What APF can you use for defects involving the shoulder, forelimb, elbow, axilla, and thorax??

Answer 25

Thoracodorsal APF

Question 26

What artery is supplying a thoracodorsal APF?

Answer 26

Cutaneous branch of the thoracodorsal artery and vein

Question 27

What is a important complication in thoracodorsal APF??

Answer 27

Partial flap necrosis -> on average 21% of the flap is affected

Can be managed by 2nd intention healing

occurs in about 70% of cases

Question 28

When could you use a cranial superficial epigastric APF?

Answer 28

Sternal defects

Question 29

What type of APF is good for medial and lateral tibial defects?

Answer 29

Genicular APF

Question 30

In what cases is a deep circumflex iliac APF appropriate ?

Answer 30

Defects over the greater trochanter and lateral pelvic area

Question 31

What is a composite flap??

Answer 31

Flaps of skin with muscle, bone, or cartilage

Myocutaneous are the most common

Question 32

What muscles are conductive to sacrifice for flap formation???

Answer 32

Latissimus dorsi 
Cutaneous trunci 
Gracilis 
Semitendiosis 
Trapezius 

—> easy to access, elevate, and have direct cutaneous arteries exiting the muscle surface to supply overlying skin

Question 33

What type of flap can you use for a thoracic wall defect like a chest wall reconstruction??

Answer 33

Latissimus dorsi myocutaneous flap

Question 34

When are muscles flaps used??

Answer 34

To fill defects, repair hernias, and treat paralysis

Question 35

What flap is elastic, mobile, and large, and is used to facilitate repair of defects in the abdominal wall or caudal thoracic wall??

Answer 35

External abdominal oblique

Question 36

What flap is used to repair prepubic tendon ruptures or femoral hernias when tissue trauma, retraction, and fibrosis preclude adequate anatomic reapposition??

Answer 36

Cranial sartorius muscle flap

Question 37

What flap can be used to cover defects of the tibial or metatarsal area or can facilitate fracture repair when healing is impaired by osteomyelitis/poor circulation

Answer 37

Caudal sartorius muscle flap

Question 38

What flap is used to close orbitonasal defects or improve cosmetics after orbital exenteration?

Answer 38

Temporalis muscle flap