Skin grafting

Question 1

A skin graft is a portion of skin that has been separated from its vascular supply

Answer 1

T

Question 2

Full-thickness grafts (epidermis and dermis plus adnexal structures) are more appropriate where a large area is to be grafted.

Answer 2

F

This is true for split thickness grafts.

Question 3

Split-thickness grafts (epidermis and partial-thickness dermis only) generally give better retention of skin function.

Answer 3

F

This is true for FTSG.

Question 4

Disadvantages of grafts include creation of a second surgical site and suboptimal tissue colour and texture match if an improper donor site is selected.

Answer 4

T

Question 5

Patients typically will eventually experience full sensation at the graft recipient site.

Answer 5

F

Rarely, even after prolonged periods.

Question 6

Split-thickness grafts contain few or no adnexal structures.

Answer 6

T

Question 7

Composite grafts consist of skin and a second type of tissue, most often cartilage.

Answer 7

T

Question 8

A homograft is a graft taken from a donor site on an individual and placed at a recipient site on that same individual.

Answer 8

F

This is an autograft.

Question 9

An autograft is a graft taken from an individual and transplanted to another individual of the same species.

Answer 9

F

This is a homograft.

Question 10

A xenograft (heterograft) is a graft that is transplanted between species (eg. pig to human).

Answer 10

T

Question 11

Re-establishment of a blood supply at the recipient site is essential for graft survival.

Answer 11

T

Question 12

Imbibition is the first stage of graft survival – it is an ischaemic period that lasts for the first 24-48 hours.

Answer 12

T

Question 13

During imbibition, the graft becomes oedematous, but does not increase its weight.

Answer 13

F

Weight increases by up to 40%.

Question 14

During imbibition, fibrin attaches the graft to its bed, the graft is sustained by plasma exudate from the wound bed, and nutrients are obtained by passive diffusion.

Answer 14

T

Ultimately the fibrin ‘glue’ is replaced by granulation tissue.

Question 15

The second stage of graft survival is neovascularisation.

Answer 15

F

Inosculation.

Question 16

The third stage of graft survival is inosculation.

Answer 16

F
Neovascularisation
inosculation is second stage
But 2nd and 3rd stages occur concurrently

Question 17

Inosculation is a process of revascularisation, resulting in the linkage of the graft’s dermal vessels to those present in the recipient bed.

Answer 17

T

Question 18

The process of inosculation begins as early as 48-72hrs and lasts for 7-10 days.

Answer 18

T

Occurs concurrently with neovascularisation

Question 19

Despite the fact that exposed bone and cartilage are poor substances for grafts, delayed grafting at sites initially devoid of periosteum or perichondrium allows for the development of granulation tissue and improved chance of subsequent graft survival

Answer 19

T

Question 20

Neovascularisation refers to capillary ingrowth to the graft from the recipient base and sidewalls.

Answer 20

T

Question 21

Neovascularisation and inosculation typically occur at separate times during healing.

Answer 21

F

Often occur in conjunction.

Question 22

The rate at which a skin graft revascularises is a function of both the fraft thickness and the recipient bed vascularity.

Answer 22

T

Question 23

Under optimal healing condition, full circulation can be restored to a graft after 2 weeks.

Answer 23

F

Between the 4th and 7th day.

Question 24

Re-establishment of lymphatic flow occurs concurrently with restoration of the blood supply and is usually completed by the end of the first week of graft healing.

Answer 24

T

Question 25

Upon return of lymphatic drainage, the graft begins to lose the weight that was acquired during imbibition and likewise begins to lose the bulkiness noted earlier in the healing process.

Answer 25

T

Question 26

Reinnervation of grafts occurs simultaneously with blood revascularisation and return of lymphatic drainage.

Answer 26

F | Slow process – begins within 2 months, may not be complete for years (if at all).

Question 27

Medical issues relevant to skin grafting include coagulation abnormalities, alcohol consumption, smoking, vascular disease, metabolic derangements, and poor nutrition.

Answer 27

T

Question 28

FTSGs generally have greater wound contracture than STSGs.

Answer 28

F | The opposite is true.

Question 29

The metabolic demands limit the overall size of a FTSG to 4-5cm, but STSGs can be used to repair very large defects.

Answer 29

T

Question 30

Sites where STSGs are commonly utilized include the nasal tip and ala, helical convexities and concavities, medial canthus, digits and extremities.

Answer 30

F | This is true for FTSGs.

Question 31

Factors contributing to donor site selection include skin colour, tissue texture, amount of photodamage, and the presence or absence of hair.

Answer 31

T

Question 32

Most common donor sites include preauricular skin, postauricular skin, clavicular and inner upper arm regions, the mesolabial fold and upper eyelids.

Answer 32

T

Question 33

Harvested grafts should be oversized by 40-50% to prevent obtaining a final graft that is too small.

Answer 33

F | 10-20%.

Question 34

Defatting of the graft is performed effectively with curved iris scissors.

Answer 34

T

Question 35

Leaving fat on the graft serves as a barrier to nutrient diffusion between the recipient bed and the graft dermis.

Answer 35

T

Question 36

Remoistening the graft periodically with sterile saline or local anaesthetic during the defatting procedure is not recommended.

Answer 36

F | Is recommended to prevent desiccation.

Question 37

The graft recipient site should not be undermined.

Answer 37

F | Undermine by several mm.

Question 38

Meticulous haemostasis of the recipient site is not necessary.

Answer 38

F | This is crucial.

Question 39

Excessive elctrocoagulation of the wound bed must be avoided, so that abundant devitalised tissue is not present.

Answer 39

T

Question 40

A subcutaneous or myocutaneous hinge flap can be utilised prior to graft placement to more fully occupy the base of the recipient site with well-vascularised tissue.

Answer 40

T

Question 41

Buried sutures should not be placed to anchor the graft.

Answer 41

T | This increases the risk of haematoma.

Question 42

The optimal suturing technique is with the needle entering the graft first, which results in less ‘lifting’ tendency of the graft from its new base.

Answer 42

T

Question 43

Excessively superficial suturing on the graft onto its recipient bed has been implicated as a potential aetiology of graft pin-cushioning.

Answer 43

T

Question 44

Basting sutures should not be placed to anchor the central portion of the graft.

Answer 44

F | These secure the central portion, protecting it from shearing forces.

Question 45

Tie-over bolsters are essential for good surgical outcome

Answer 45

F

Question 46

Silk sutures are ideal for tie-over bolsters, due to their excellent knot security and handling properties.

Answer 46

T

Question 47

Tie-over sutures can be placed entirely within the surrounding recipient skin or between the simple interrupted sutures anchoring the graft.

Answer 47

T

Question 48

A bolster consists of a thick layer of antibiotic ointment or petrolatum applied over the graft, followed by a non-adherent contact layer, with a bulky material making up the final layer.

Answer 48

T

Question 49

A Burow’s graft is a FTSG in which the grafted tissue is obtained from skin not adjacent to the defect.

Answer 49

F | Adjacent.

Question 50

Grafts from the crown of the scalp are best used as donor sites on the scalp.

Answer 50

F | Occipital and temporal – least likely to undergo AGA.

Question 51

Hair-bearing grafts should be defatted using the same technique as for non-hair bearing skin.

Answer 51

F | Should be defatted minimally or not at all in order to preserve follicles.

Question 52

Orientation of hair-bearing grafts is unimportant.

Answer 52

F | Need to orient so hairs in same direction as surrounding skin.

Question 53

Thin STSGs are 0.125-0.275mm thickness.

Answer 53

T

Question 54

Medium STSGs are 0.275-0.4mm thickness.

Answer 54

T

Question 55

Thick STSGs are 0.40-0.75mm thickness.

Answer 55

T

Question 56

STSGs can be harvested with free-hand use of a #10 or #15 blade, a Weck blade or a dermatome.

Answer 56

T

Question 57

Using a free-hand blade to take a STSG has the advantage of being easy to obtain a graft with uniform thickness

Answer 57

F | It is very difficult to obtain a graft with unform thickness

Question 58

A Weck blade should be held at a 45 degree angle to the skin during harvesting.

Answer 58

F | Virtually parallel.

Question 59

Air-driven or electric dermatomes should be used when STSGs are necessary to cover larger defects that are several cms in size or greater.

Answer 59

T

Question 60

Meshing STSGs increases the coverage area by 50-60%.

Answer 60

F | 25-35%.

Question 61

Donor sites for STSGs include the upper thigh, lateral hips, inner aspects of the upper arms, low back, and abdomen.

Answer 61

T

Question 62

Moist occlusion of the STSG donor site significantly decreases post-operative pain and promotes re-epithelialisation.

Answer 62

T

Question 63

The STSG donor site usually re-eptihelialises over 4-5 weeks.

Answer 63

F | 2-3 weeks.

Question 64

The STSG donor site typically remains pink for several months, and later become hypopigmented

Answer 64

T

Question 65

There is significant drainage at the donor site of a STSG for the initial 24 hours

Answer 65

F | 48hrs

Question 66

The maximum graft diameter for a composite graft is 1-2cm, to minimise the risk of necrosis.

Answer 66

T

Question 67

The crus of the helix is the most commonly used donor site for composite grafts.

Answer 67

T

Question 68

The reverse tongue-in-groove technique for composite grafting requires no oversizing of the graft when compared to the defect site.

Answer 68

F | 5-10% oversizing due to predictable contaction of the graft over time.

Question 69

It is not necessary with composite grafting to avoid placing excessive cartilage.

Answer 69

F

Question 70

Post-operative necrotic debris should be removed from the graft bed as it signals complete graft loss.

Answer 70

F | Often viable graft underneath so leave intact.

Question 71

Delayed grafts are most commonly necessitated for defects with a significant amount of exposed bone or cartilage, where greater than 25% of the periosteum or perichondrium is lacking.

Answer 71

T These recipient bases often provide inadequate nutrition and grafts placed directly over them are at increased risk of necrosis.

Question 72

On the day of surgery for the delayed graft the recipient site is gently scrubbed with a sterilizing agent as these wounds are likely to be colonised with bacteria despite antibiotics

Answer 72

T

Question 73

Preparation for delayed grafting involves beginning oral antibiotics one day prior to the procedure and continuing for 4 days postoperatively.

Answer 73

T

Question 74

Porcine xenografts are occlusive biological dressings that promote granulation and may remain in place for 7-14 days.

Answer 74

T

Question 75

Dermal grafts are fragments of skin from which the epidermis has been removed.

Answer 75

T

Question 76

Dermal grafts can be used as filler and contouring material in wounds on convex surfaces.

Answer 76

T

Question 77

Complications of dermal grafts occur rarely, but include epidermal cyst formation.

Answer 77

T | Epidermal cysts occur in ~10% cases.

Question 78

Dermal grafts negate the need for definitive repair with a graft or flap.

Answer 78

F | graft on top

Question 79

The biggest risk to graft survival comes from the patients themselves.

Answer 79

T

Question 80

At 1 week, FTSGs are typically violaceous in appearance.

Answer 80

T

Question 81

One of the clues that the surface of a FTSG is truly necrotic is a ‘gummy ‘ or ‘spongy’ feel with gentle pinching of the surface with toothed forceps.

Answer 81

T

Question 82

The patient can begin to treat a graft recipient site as normal skin, including the use of cosmetics, at two weeks.

Answer 82

F | One month

Question 83

STSGs are pink-to-skin coloured as early as one week.

Answer 83

T

Question 84

Re-epithelialisation of fenestrations of extensively meshed grafts can require up to 2-4 weeks.

Answer 84

F | 6-8 weeks

Question 85

STSGs have a tendency to become dry, scaly and hyperkeratotic over time.

Answer 85

T | need to use liberal emollient.

Question 86

Routine antibiotics are required in the perioperative skin graft period

Answer 86

F

Question 87

The most common complication leading to loss of any graft is fluid accumulation at the graft base that elevates it from the recipient bed.

Answer 87

T

Question 88

Antibiotics should be used for delayed grafts, or in cases where to surgical wound has been open for a prolonged period (>6hrs) or for surgical sites close to the mouth or nostrils.

Answer 88

T

Question 89

Long-term complications of skin grafts include poor cosmesis and functional deficits such as ectropion and nasal valve collapse.

Answer 89

T

Question 90

FTSGs are nearly always aesthetically inferior to STSGs.

Answer 90

F | Other way round.

Question 91

The anatomic sites most likely to be susceptible to the effects of graft contracture are the eyelid, vermillion border of the lip, and nasal ala, since they have ‘free margins’

Answer 91

T