Overview
Definition:
A split-thickness skin graft (STSG) is a surgical procedure where the epidermis and a portion of the dermis are harvested from a donor site and used to cover a recipient wound bed
It is distinct from a full-thickness skin graft (FTSG) which includes the entire dermis
STSG provides a resurfacing option for large or deep wounds where FTSG would not be feasible due to donor site limitations or contracture concerns.
Epidemiology:
Skin grafting is a common reconstructive procedure performed worldwide
The incidence of STSG use varies based on trauma, burns, surgical excisions (e.g., oncologic), and chronic wound prevalence
Large-scale epidemiological data specific to STSG is limited, but it is a cornerstone in managing extensive skin loss.
Clinical Significance:
STSG is crucial for restoring skin coverage over exposed vital structures, improving wound healing, preventing infection, reducing pain, and optimizing functional and aesthetic outcomes
Its successful application is vital in managing complex wounds in trauma, burns, and reconstructive surgery, directly impacting patient recovery and quality of life
Understanding STSG harvest and grafting is fundamental for surgical residents preparing for DNB and NEET SS examinations.
Indications
Indications For Harvest:
Large surface area defects
Wounds with exposed bone, tendon, or muscle where adequate vascularity is present
Deep partial-thickness burns
Large excisions of skin tumors or infected tissue
Chronic non-healing ulcers where granulation tissue is healthy.
Contraindications To Harvest:
Unhealthy recipient wound bed (e.g., heavy infection, necrotic tissue, exposed periosteum without granulation)
Compromised donor site vascularity
Systemic conditions severely impairing healing (e.g., uncontrolled diabetes, malnutrition)
Active malignancy at the donor site.
Recipient Site Preparation:
Thorough debridement of necrotic or infected tissue
Creation of a healthy, well-vascularized granulation bed
Hemostasis to prevent hematoma formation
Wound closure or coverage to protect the graft bed.
Harvesting Technique
Donor Site Selection:
Common sites include the anterolateral thigh, buttocks, abdomen, and calf
Factors influencing selection: availability of sufficient surface area, graft thickness requirements, minimal scarring for aesthetic reasons, and patient positioning convenience
Avoid areas of poor vascularity or pre-existing skin conditions.
Instrumentation:
Skin graft mesher (for expanding the graft)
Dermatome (power or electric, or manual Hoffm an)
Grafting carrier or bolster
Suction drain (if needed)
Scalpels, forceps, scissors
Mineral oil or sterile saline for lubrication.
Dermatome Setting:
The dermatome is set to achieve the desired graft thickness
Typical STSG thicknesses range from 0.010 inches (0.25 mm) for superficial wounds to 0.035 inches (0.9 mm) for deeper defects or where better graft take is crucial
Thicker grafts have better long-term outcomes but poorer donor site healing.
Harvest Procedure:
The donor area is lubricated
The dermatome is applied and advanced smoothly to harvest a continuous sheet of skin
The harvested graft is immediately inspected for completeness and then transferred to the recipient site or meshed for increased surface area coverage
The donor site is dressed with an occlusive or semi-occlusive dressing to promote re-epithelialization.
Grafting And Dressing
Graft Preparation:
The harvested STSG is trimmed of any excess subcutaneous fat
It is then debrided of any adherent tissue
If meshed, it is typically laid onto a carrier material with the holes facing upwards.
Recipient Site Application:
The graft is carefully positioned onto the prepared wound bed, ensuring complete contact without wrinkles or folds
The graft is then secured to the wound edges using sutures or surgical staples
The center of the graft may be sutured down to prevent undermining.
Dressing Techniques:
Several dressing techniques exist
The graft may be secured with sutures or staples
A non-adherent contact layer (e.g., petroleum-impregnated gauze, silicone mesh) is placed over the graft
This is followed by absorbent gauze and an outer protective layer
Immobilization of the grafted area is crucial
Bolster dressings, tie-over dressings, or vacuum-assisted closure (VAC) can be employed.
Postoperative Care Recipient Site:
Strict immobilization of the grafted area for the first 5-7 days is paramount to allow for neovascularization and adherence of the graft
Monitor for signs of infection, graft slippage, hematoma, or seroma
Pain management and antibiotic prophylaxis are standard.
Donor Site Care
Dressing Choices:
Primary dressings aim to protect the wound and promote healing
Options include occlusive (e.g., synthetic skin substitutes, silicone sheets), semi-occlusive (e.g., hydrocolloids, films), or absorptive dressings
The goal is to maintain a moist environment for re-epithelialization.
Healing Process:
STSG donor sites heal by re-epithelialization from the remaining dermal appendages (hair follicles and sweat glands)
Healing typically occurs within 7-14 days, depending on graft thickness and patient factors
Thicker grafts take longer to heal.
Potential Donor Site Issues:
Pain, infection, delayed healing, hypertrophic scarring, dyspigmentation (hypo- or hyperpigmentation), and contracture
Proper dressing selection and wound care are key to minimizing these issues.
Complications
Early Complications:
Graft loss (partial or complete) due to hematoma, seroma, infection, shear forces, or inadequate recipient bed preparation
Bleeding from donor or recipient site
Superficial donor site infection
Pain.
Late Complications:
Graft contracture leading to functional or aesthetic deformities
Scarring (hypertrophic or keloid) at donor or recipient site
Dyspigmentation
Chronic donor site pain
Re-epithelialization failure of donor site
Graft-vessel disease (rare).
Prevention Strategies:
Meticulous hemostasis
Adequate recipient site preparation and debridement
Proper graft handling and secure fixation
Immobilization of the grafted area
Judicious use of antibiotics and appropriate dressing choices for both donor and recipient sites
Patient education on wound care and activity restrictions.
Key Points
Exam Focus:
Differentiating STSG from FTSG
Indications and contraindications for STSG
Donor site selection criteria
Dermatome settings and graft thickness
Principles of recipient site preparation
Graft fixation and dressing techniques
Donor site healing mechanisms and potential complications
Management of graft loss
Importance of immobilization.
Clinical Pearls:
Always ensure adequate hemostasis before graft placement
Meshing a graft increases its surface area coverage but may compromise its vascular integrity slightly
Immobilization is the single most critical factor for graft take
Consider donor site location based on the recipient defect and patient aesthetics
Monitor donor sites closely for signs of delayed healing or infection.
Common Mistakes:
Placing grafts on unhealthy beds
Inadequate debridement
Insufficient graft fixation
Neglecting immobilization
Using an overly thin graft for a deep defect
Poor donor site care leading to delayed healing or scarring.