Skin flaps Flashcards
How is circulation supplied to the skin?
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)
What is a subdermal plexus flap?
Full thickness “tongue” of skin
Detached from surrounding skin along 3 of 4 quadrants
What does flap survival rely on?
Remaining collateral circulate from the remaining cutaneous attachment and its vasculature which is the subdermal plexus (SDP)
How long should your subdermal plexus flap be?
At least as long as the wound —> 1.5x length
What are the pivotal flap types??
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
What are the types of advancement flaps??
Single pedicle
Bipedicle or H-pasty
V-Y plasty
What is pantographic expansion??
When you cut broader at the base, you get extra length/ tension relief in your skin flap
The effective length of a pivotal flap moving through an arc of 180 degrees is reduced by ____%
40
What type of skin flap is commonly used for defects at the elbow or on the flank?
Transposition flap
—> elbow fold flap and flank fold flap
What type of flap has a pedicle away from the defect that must pass over or under intervening tissue?
Interpolation flap
What type of flap is used for full thickness circumferential wounds to distal limbs??
Distant flap/pouch flap
What are complications of subdermal plexus flaps???
Infection Seroma Desensitization and self trauma Skin edge dehiscence Global flap necrosis
How can you avoid infection when doing a subdermal plexus flap??
Don’t do flap until recipient bed has healthy granulation tissue
Aseptic technique
What can lead to skin edge dehiscence ?
Excessive tension
Infection
Seroma
Pre-existing dz (DM/Cushing/Radiaiton)
What can lead to global flap necrosis??
Compromise of blood supply
- > iatrogenic (most common)
- > thrombosis
- > self-trauma
What type of flap relies on a direct cutaneous artery and vein at the base of the flap?
Axial pattern
What benifit do axial pattern flaps have over subdermal plexus flaps??
Have better perfusion
What is an island arterial flap?
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
When are axial pattern flaps most commonly used?
Wound closure after tumor resection or trauma
How does the survival rate of axial pattern flaps compare to sub-dermal plexus flaps ?
Axial pattern flaps survival rate is 2x that for subdermal plexus flaps
What are the axial pattern flaps that can be used in a dog?
Caudal auricular Omocervical Thoracodorsal Caudal superficial epigastric Lateral genicular Deep circumflex iliac Lateral caudal Superficial brachial Superficial temporal
What axial pattern flaps can be used in cats?
Caudal auricular
Thoracodorsal
Caudal superficial epigastric
Superficial temporal
What are the landmarks for the caudal superficial epigastric APF?
Medial - midline of abdomen
Lateral - parallel to medial at equal distance from teats
Length - variable, can include last 4 glads
What type of APF can be used for repair of caudal abdominal, inguinal, preputial perineal thigh, and stifle defects??
Caudal superficial epigastric
What APF can you use for defects involving the shoulder, forelimb, elbow, axilla, and thorax??
Thoracodorsal APF
What artery is supplying a thoracodorsal APF?
Cutaneous branch of the thoracodorsal artery and vein
What is a important complication in thoracodorsal APF??
Partial flap necrosis -> on average 21% of the flap is affected
Can be managed by 2nd intention healing
occurs in about 70% of cases
When could you use a cranial superficial epigastric APF?
Sternal defects
What type of APF is good for medial and lateral tibial defects?
Genicular APF
In what cases is a deep circumflex iliac APF appropriate ?
Defects over the greater trochanter and lateral pelvic area
What is a composite flap??
Flaps of skin with muscle, bone, or cartilage
Myocutaneous are the most common
What muscles are conductive to sacrifice for flap formation???
Latissimus dorsi Cutaneous trunci Gracilis Semitendiosis Trapezius
—> easy to access, elevate, and have direct cutaneous arteries exiting the muscle surface to supply overlying skin
What type of flap can you use for a thoracic wall defect like a chest wall reconstruction??
Latissimus dorsi myocutaneous flap
When are muscles flaps used??
To fill defects, repair hernias, and treat paralysis
What flap is elastic, mobile, and large, and is used to facilitate repair of defects in the abdominal wall or caudal thoracic wall??
External abdominal oblique
What flap is used to repair prepubic tendon ruptures or femoral hernias when tissue trauma, retraction, and fibrosis preclude adequate anatomic reapposition??
Cranial sartorius muscle flap
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
Caudal sartorius muscle flap
What flap is used to close orbitonasal defects or improve cosmetics after orbital exenteration?
Temporalis muscle flap
