Chapt 79: Skin Graft Flashcards
different sizes of split thickess skin graft
thin: 0.008 to .012 “
intermediate: 0.013-0.016”
thick: 0.017-.02
the graft that will llkely take
STSG: there are more blood vessels in the superficial dermis thats transected which could aid in revasc. and has less tissue to support with blood supply
graft with greater contraction
STSG- less dermis
graft prone for hyperpigmentation
STsg
more durable graft
full thickness
better cosmetic
full thickness
common complications for STSG
hematoma(most common)/seroma
infection-2nd most commonn: Group A strep, pseudomonas will prevent graft from adhering
shearing forcess
poor vascularity of exposed bones/tendons
survival rate or STSG vs FTSG
5 days-Stsg, FTSG: 3 days
so if seroma or hematoma is present on STSG, it may still survive
common donnor sites for FtSG
flexor creases: poplitea fossa, inguina area, gluteal fold
“pinch” area- sinus tarsi
3 phases of skin graft healing
plasmatic phases/imbibition: 24-48 hr
capillary budding, graft still ischemic - passively absorbs nutrients in wound bed by diffusion
inosculation: (48-72 hrs): capillary budding in contact with graft
angiogenesis/reorganization: day 5-new blood vessels grow into graft, graft become vascularized
what consists of a skin flap
skin and subq transferred or rotated to restore tissue defect; has some of its own vascular supply
where on the flap retains vasculairty
base of flap: pedicle
what type of graft has better function
thicker graft
in order for the graft to “take”, what is important?
absence of motion, infection, hemostasis, stent dressings (dressing designed for skin graft to hold graft in place, apply pressure, and absorb fluid): adap6tic, saline soaked gauzed, fluff, held by tie-over sutures securing of graft.
requires a vascular recipient site, cannot be placed over bone or tendon which has less vascularity
isograft
graft of tissue between two individuals who are genetically identicial
xenograft
a graft of tissue from one species used on another species
what is the ratio of the full thickness skin graft in order for adequate closure
3:1 length to width: elliptical incision
common donor sites for STSG
anterior/lateral thigh, upper inner arm, gluteal region, dorsum of foot
limberg flap orientation
longitudinal axis is parallel to the line of minimal skin tension
for z plasties, how should the lines be placed
diagonal lines should be the same length as the scar
how much length will 45 deg and 60 deg z plasty get
45 deg: 50% length; 60 deg:75%
good for linear scar contractures
what are the consequences if angles are less than 45 or more than 60 for z plasties
45 deg results in impaired blood flow to flaps
>60 deg: severe tension, extreme lengthening
V-Y plasty placement
apex of V placed at the point of maximal tension
V-Y plasty good for what type of contractures and allows for how much lengthening
V-Y are useful for lengthening contractures or in reducing contracted digits across the MPJs. Commonly treats overlapping 5th digits.
good for unidirection skin lengthening technique
20% increase in length
the cincinnati incision is common for what procedure
soft tissue release for club foot
indications for skin flap
- Areas with poor vascularity (bare bone or tendon)
- Reconstruction for full thickness
- bad bony prominences
rotational flap
semi-circular flap (ideally 1/2 circle) that is rotated pivot towards adjacent defect. Donor site is closed or grafted
. Z-Plasty
- Transposition of 2 triangular flaps
- Make transverse central incision parallel to the contracted skin
- Arms of Z are EQUAL (all arm lengths are aequal) with flap to tip angle 60 Degrees (can give about 75% increase in length)
V-Y Plasty for skin lengthening
- Apex of V is proximal in foot - distal skin is advanced
2. Entire V may be undermined beneath superficial fascia for exposure
random pattern flap vs axial pattern flap
random pattern flap: lack a primary artery and vein and rely on perfusion of dermal-subdermal vessel from the pedicle of the flap (length to base ratio should be 1:1)
axial pattern flaps contain a primary artery and vein that are incorporated into pedicle of he flap. therefore, perfusion depends on axial artery rather than the width of the pedicle and cutaneous perfusion
Rotational vs transpositional vs interpolational flaps vs advancement flaps
rotational flap: semicircular and rotated about a pivot point
transpositional flap rotated about a point but are linear dimensions such as squares and rectangles
interpolational flaps are rotated about a pivot point but flap must pass over or under intact tissue between donor and recipient sites. The defect is not immediately adjacent to defect
advancement flap: fixed point that are stretched as donor tissue into recipient bed (ie bipedicle flap or V to Y flap)
For a Y-V approach, what direction does the lengthening occur?
lengthening occurs perpendicular to the stem of the Y because the flap is advanced in direction of the apex
what type of flap is a a limberg flap? advantages to this flap
This is a random pattern, transpositional flap in a shape of rhombus.
advantages to this flap is that it preserves a large amount of normal skin adjacent to the deficit that would otherwise been excised with a standard elliptic flap
disadvantage of limber procedure
skin must be mobile to prevent excessive tension across the flap and obtain closure to donor site.
common donor sites for free vascularized flaps
latissimus dorsi, rectus abdominis, groing, gracilis, serratus anterior , radial forearm fasciocutaneous flap
what types of flaps can be used to cover chronic osteomyelitis to increase blood perfusion to the area and availability of systemic antibiotics
Free muscle flaps
what is the most common disadvantage /complication causing free flap failure
microvascular techniques is needed for reanastomosis because VENOUS or Arterial thrombosis are MAJOR causes of free flap failure
technical skill and instrumentation needed
when are muscle flaps useful
covering soft tissue defects when bulk, padding, and vascularity are needed to cover a wound
what is a common complication of a reverse sural artery flap
venous congestion
