Skin Flaps and Grafts Flashcards
Skin Flap (aka pedicle graft or pedicle flap)
- Portion of skin and subcutaneous tissue with a vascular__ attachment moved from one area of the body to another
- Blood flow is maintained or immediately re-established when skin segment is moved to new position
Skin Graft
- A segment of skin that is completely removed from the body and transferred to a recipient site
- Blood supply is severed and new vessels must grow in from recipient site
Indications for skin flaps
- Defects with poor vascularity
- Areas difficult to immobilize
- Defects overlying cavities (ex orbit)
- Areas where padding and durability essential
Skin graft indications
- Major loss of skin (trauma, tumor removal)
- Distal extremities
- Full-thickness burns
Skin Flap Classification
- Location
- Distant from the defect
- Adjacent to defect
- Blood supply
- Subdermal plexus flaps
- Axial pattern flaps
- Tissue types
- Just skin and subcutaneous tissue
- +/- muscle, cartilage, and bone
Axial pattern flaps
- Blood supply from direct cutaneous artery and vein
- Excellent blood supply!!!
Subdermal plexus flaps
- Blood supply from subdermal plexus - from terminal branches of direct cutaneous artery
- Includes all other types of flaps
Local flaps - flaps that rotate around a pivot point
- Rotation flaps
- Transposition flaps
Local flaps - flaps that do not rotate around a pivot point
- Single pedicle advancement flaps
- Bipedicle advancement flaps
- H-plasty flaps
- V-Y advancement flaps
Rotational flaps
- Local flaps are pivoted over a defect.
- Flap and defect share a common border!
- Create incision in stepwise fahsion until no tension

Transposition flaps
- Rectangular flap created within 90 degree of the long axis of the defect
- Width of flap = width of defect
- Note the effect of rotation on flap length - will decrease flap length

Interpolation Flaps
- Rotating rectangular flap that lacks a common border with the skin defect
- Flap covers skin between donor and recipient
- Second surgery to excise redundant skin
- *you leave the pedicle intact - otherwise it would be considered a skin graft

Single-Pedicle Advancement Flaps
- One of the most commonly used in vet med
- Formed in loose, elastic skin and slid over the dfeect
- Flap incisions made parallel to lines of least tension!

H-plasty (bi-pedicle advancement flaps)
- two advancement flaps coming from either direction to meet eachother in the middle
- Cut triagnles out again to prevent dog ear effect
- As it comes together, sutured at an H

Pouch, hinged, and tube pedicle flaps
- Location - distant flaps (skin still stays on pedicle!)
- Blood supply - subdermal plexus
- Multi-stage procedures
- Used more for lower extremity skin defects
Pouch Flaps
- Create two incisions - undermine - then give a dog or cat a pocket to stick the paw in
- Secondary surgery - excise area of pouch that had been left in tact
- Excise dorsal and ventral margin
- Then close the original wound

Tubed Pedicle Flaps
- Two parallel incisions - sutured to eachother around tube
- Closing up the wound underneath the tube
- Tube needs to heal entirely (10-14 days)
- Tube of skin hanging off the patient - excise upper/proximal portion of the tube and walk tube down to area of interest

Axial Pattern Flaps
- Flaps that include a direct cutaneous artery and vein at the base of the flap
- Advantage: able to transfer large skin segments in a single stage without the need for delay procedure
- Already have an excellent blood supply, better flap survivial
- Disadvantage: limited on areas of the body that these flaps can be developed
One of the most commonly used axial pattern flaps is:
Caudal superficial epigastric axial pattern flap

Caudal superificial epigastric axial pattern flap
- Ventral midline is medial incision
- Lateral incision is parallel to the first, at a distance equal to the distance from the mammary teats to the midline
- I.e - teats will be the midpoint of the flap
- Cranial extent is between 1st and 2nd glands

Major points when planning skin flaps
- Base of flap too narrow = flap necrosis
- Flaps fixed to recipient bed without tension
- Ideally, plan so color and direction of hair growth matches recipient bed
Thoracodorsal axial pattern flap
- Defects involving the shoulder, forelimb elbow, axilla, and thorax (down to carpus in cat)
- Cranial border will be the scapular spine
- Caudal border parallel to spine twice the distance from the acromion to the caudal shoulder depression
Successful skin graft healing
- Depends on:
- Establishment of arterial connections
- Adequate drainage
- Recipient bed:
- Healthy granulation tissue
- Free of infection or debris
- Grafts will not take:
- Bone, cartilage, tendon or nerves
- Infection, crushed tissues, irradiated tissues, avascular fat, chronic ganulation tissue
Acceptance of grafts
- Plasmatic imbibition
- Serum-like fluid and cells pulled from the recipient bed into the graft vessel
- Nourishment of the graft
- Edema for 48-72 hours
- Inosculation
- Anastomosis of recipient bed vessels with graft
- 24-72 hours
- Vascular ingrowth
- From the bed into the graft
- 48 - 72 hours
Full-thickness grafts
- Consists of epidermis and dermis
- Includes hair follicles and adnexal structures
- Best cosmetic appearance and function
- Most common in vet med
Recipient bed preparation
- Lightly scrape with scalpel blade to remove surface debris and exposure capillaries
- Cover bed with moist sponges soaked in CHX solution while graft is being prepared
Mesh Grafts
- Pros
- Allows expansion of graft to cover larger defects
- Allows drainage of blood and serum from under graft
- Allow graft to conform better to uneven structures
- Application
- Suture or staples on all free edges and midline


Punch grafts
Donor site of skin grafts
- Typically taken from the dorsal or lateral trunk
- Close or treat as open wound
Post-op care for skin grafts
- Apply antibiotic ointment and nonadherent dressing (adaptic)
- Absorbent secondary layer
- Protective tertiary layer
- Splint or cast if over joint
- Change dressing in 72 hours, then daily