Graft – tissue excised and transferred to a graft host bed, where a new blood supply develops
Taking of the graft takes 96 hours and occurs in two stages:
Imbibition
- Nutrients absorbed passively from graft bed, for about 48 hours
- Graft temperature is less than core body temperature
Inosculation
- True establishment of microcirculation in the graft, for about 48 hours
- Temperature of graft increases to core body temperature
Split thickness skin grafts
- Epidermis only with superficial dermal plexus (small but numerous vessels)
- Few lymphatics
- Physical characteristics of host site not carried – therefore brittle and less durable
- Contracts more
- Often meshed – allows expansion and also drainage of fluid/collections
- Takes more readily than FTSG
- Harvest with a dermatome, usually lateral upper thigh
Full thickness skin grafts
- Epidermis and dermis, with deep dermal plexus carried (larger vessels but more sparse)
- Carries lymphatics
- Physical properties transferred
- Does not contract as much as STSG as collagen included in dermis
- More fastidious (less likely to take readily and requires optimal conditions)
Buccal mucosal grafts
- Non keratinised mucosa, with optimal vascular characteristics
- Pan laminar plexus with optimal rich vascular characteristics
- Easy to harvest
- Resilient to infection
- Used to a wet environment (“wet epithelial surface”)
- No hair glands
Other types of graft – bladder epithelial, peritoneal, vein patches, rectal mucosal grafts, dermal grafts, tunica vaginalis
Flap – transfer of tissue with its own blood supply (either intact, or disconnected and reconnected in a free flap)
Classified by blood supply:
- Random flap – no identifiable arteriovenous pedicle, survival dependent on superficial and deep dermal plexus.
- Restricted by length/width ratios
- Axial flap – identifiable artery and vein through base
- Myocutaneous – arteriovenous pedicle within muscle, skin paddle attached to muscle (e.g. gracilis flap)
- Fasciocutaneous – arteriovenous pedicle within fascial layer attached to skin paddle (e.g. local penile dartos flaps)
Classified by method of elevation:
- Peninsular flap – base of flap remains in continuity (e.g. rotational flap)
- Island flap – flap remains in continuity only through arteriovenous pedicle (e.g. Martius flap)
- Free flap – arteriovenous continuity is divided then reestablished (e.g. radial artery forearm)
Gracilis flap:
- Originates from pubic arch and inferior ramus (posterior to adductor longus tendon)
- Inserts distally to medial tibia
- Dominant pedicle is from medial femoral circumflex artery from common femoral – perforating vessel found about 10 cm inferior to pubic tubercle
Above image from Tran et al “Transperineal approach to complex rectourinary fistulae” CUAJ