Minimizing Infection Risk in Split-Thickness Skin Grafting
To achieve low infection rates in STSG, prioritize meticulous wound bed preparation with bacterial counts <10^5 organisms/gram, use transparent film dressings on donor sites, and exercise heightened vigilance in patients with vascular ulcers, burns, lower extremity grafts, and diabetes.
Pre-Operative Wound Bed Preparation
The single most critical factor determining infection risk is the bacterial burden of the recipient site before grafting:
Quantitative bacterial counts should be <10^5 organisms/gram of tissue before proceeding with grafting 1. When wounds are contaminated with ≥10^7 organisms, infection develops under most grafts, whereas lower inoculum levels permit successful graft take 1.
Perform meticulous debridement of the recipient site with careful coagulation of venous bleeding to create an optimal wound bed 2. The combination of inadequate debridement and local infection accounts for most partial graft losses 2.
The type of organism is less important than the bacterial count for determining readiness for grafting 1, though this changes post-operatively (see below).
High-Risk Patient Populations Requiring Extra Precautions
Certain underlying conditions dramatically increase infection-related graft loss:
Vascular ulcers carry the highest infection risk, with 58.3% of grafts lost to infection, followed by burns at 47.4% 3. These rates far exceed traumatic defects (16.7%) and donor sites (13.5%) 3.
Lower extremity grafts and multiple-site procedures have significantly higher infection rates 3.
Patients with diabetes and vascular disease fall into the high-risk vascular ulcer category and warrant aggressive pre-operative optimization and post-operative monitoring.
Female gender and age >55 years show impaired reepithelialization, though these factors affect healing rate more than infection risk directly 4.
Pathogen-Specific Considerations
Pseudomonas aeruginosa is the dominant pathogen, causing 58.1% of infection-related graft losses and requiring 4.2 times more reoperations than other organisms 3:
Pseudomonas infections are more fulminant than other pathogens 3.
Staphylococcus aureus, Enterobacter, enterococci, and Acinetobacter are secondary concerns 3.
No correlation exists between the etiology of the defect and specific microorganisms cultured 3.
Optimal Dressing Selection
Transparent film dressings provide superior outcomes for donor sites 5:
- Healing time: 9.47 days 5
- Infection rate: only 2.5% (10/394 patients) 5
- Pain score: 1.59 on 0-10 scale 5
- Cost-effective at $0.005 per square inch 5
- Produces smooth epithelialized surfaces 5
For recipient sites with compression dressings:
- Leave initial compression dressing undisturbed for 5 days if healing is uneventful 2.
- After removal, use double layers of fatty gauze with alternating periods without dressing 2.
- Apply thin cream ointment starting in week 2 2.
Graft Type Selection
Full-thickness grafts demonstrate significantly greater resistance to infection compared to split-thickness grafts 3. When feasible in high-risk patients (vascular disease, diabetes, lower extremity sites), consider full-thickness grafts despite the more limited donor site availability.
Common Pitfalls to Avoid
Never proceed with grafting when bacterial counts exceed 10^5 organisms/gram 1. This is the most preventable cause of graft failure.
Avoid grafting over poorly vascularized wound beds including exposed tendon, bone, vessels, nerves, or implant material without soft tissue coverage 2.
Exercise caution with grafts on flexion surfaces of joints or mechanically stressed locations like the heel 2.
Do not graft in the presence of active local infection 2.
The overall infection-related graft loss rate in general plastic surgery populations is 23.5-23.7% 3, 2, but this can be reduced to approximately 3% with optimal technique and patient selection 5.