Split-thickness skin graft (STSG)
STSG · partial-thickness skin graft · Thiersch graft (historical)
A split-thickness skin graft consists of epidermis plus a variable amount of dermis (typically 0.2-0.4 mm / 8-16 thousandths of an inch) harvested with a dermatome. STSG is the workhorse for resurfacing large defects after wide local excision, on irradiated beds and for salvage reconstruction. Take depends on a vascularised wound bed, immobilisation and absence of haematoma, infection or shear. Donor sites heal by re-epithelialisation from adnexal remnants over 10-21 days.
Anatomy and thickness
- STSG = epidermis + partial dermis. Thicker grafts may have better cosmesis, but more donor morbidity.
- Thinner grafts have better take but greater secondary contracture and poorer durability.
- Thicker grafts have less contracture but require a more reliable wound bed and leave a deeper donor site.
Indications in skin oncology
- Large defects after wide local excision of melanoma, cSCC, DFSP, MCC, sarcoma.
- Defects on the scalp, lower limb, anterior shin where local flap options may be limited.
- Resurfacing of irradiated beds (after permanent paraffin margins confirm clearance).
- Temporising cover during staged reconstruction or while awaiting permanent paraffin margins.
- Salvage reconstruction over exposed muscle / fascia / paratenon / perichondrium / periosteum if vascularised.
Graft take physiology
Three sequential phases (Converse & Rapaport):
- Plasmatic imbibition (0-48 h) — graft absorbs serum from the wound bed; nutrition by diffusion.
- Inosculation (48-72 h) — graft and bed vessels align end-to-end.
- Revascularisation / neovascularisation (4-7 days) — new vascular channels form; graft becomes pink.
Failure modes: haematoma (commonest), seroma, infection, shear / movement, poor bed (avascular, irradiated, exposed bone / cortex / tendon without paratenon).
Donor sites and dressings
- Most common: anterolateral / anteromedial thigh.
- Buttock — useful in fair-skinned cosmetic-sensitive patients (concealed).
- Scalp — excellent cosmesis; minimal scar; useful in elderly.
- Upper inner arm — alternative when thigh unavailable.
- Donor site healed by re-epithelialisation from pilosebaceous and sweat-gland remnants.
- Common donor dressings: hydrocolloid (Duoderm), alginate (Kaltostat), oil-based gauze (Jelonet), transparent film, or modern foams.
- Healing 10-21 days; longer in elderly, diabetic and lower limb.
Graft preparation and fixation
- Harvest with dermatome; thickness set per indication.
- Meshing (1.5:1 or 2:1) provides expansion, drainage and conformability — accepts at expense of mesh pattern in final scar; preferred for large defects, lower limb, irradiated beds.
- Non-meshed ("sheet") graft — cosmetically superior; uses on face, neck, hand, dorsum of foot.
- Fixation method chosen according to site, contour and graft size; tie-over bolster or NPWT for difficult contours.
- Quilting fixation over large flat surfaces where needed.
- Immobilise (POP / splint) for 5-7 days post-operatively where possible.
Postoperative care and complications
- Initial dressing change at 5-7 days unless indicated earlier.
- Massage and emollient from day 14 to soften.
- Secondary contracture: significant — counsel before placing across joints; consider FTSG or local flap in those locations.
- Pigment change: hyperpigmentation common in Fitzpatrick IV-VI.
- Slough / partial loss: gentle debridement; allow re-epithelialisation; regraft if >30% loss.
References
- Adams DC, Ramsey ML. Grafts in dermatologic surgery: review and update on full- and split-thickness skin grafts, free cartilage grafts, and composite grafts. Dermatol Surg. 2005;31:1055-1067.
- Converse JM, Rapaport FT. The vascularization of skin autografts and homografts. Ann Surg. 1956;143:306-315.
- BAPRAS skin grafting consensus statement. London: British Association of Plastic, Reconstructive and Aesthetic Surgeons; 2020.
- Beldon P. Skin grafts 1: theory, procedure and management of graft sites in the community. Br J Community Nurs. 2007;12:S6-S16.
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