How do you classify free tissue flaps (free flaps)?

From the Guidelines

Free flaps are classified based on the type of tissue transferred and their vascular supply patterns, including fasciocutaneous, muscle, musculocutaneous, osseous, and composite flaps, as well as axial pattern and perforator flaps. The main categories of free flaps include:

• Fasciocutaneous flaps (skin and fascia, like the radial forearm or anterolateral thigh flap)
• Muscle flaps (such as the latissimus dorsi or rectus abdominis)
• Musculocutaneous flaps (muscle with overlying skin)
• Osseous flaps (bone tissue, like the fibula)
• Composite flaps (multiple tissue types) These classifications are further divided by their vascular anatomy into axial pattern flaps (with a defined arteriovenous system) or perforator flaps (where vessels perforate through deeper tissues to supply the flap) 1. The selection of an appropriate free flap depends on the defect characteristics, recipient site requirements, donor site morbidity, and the patient's overall condition, as highlighted in the prevention and management of osteoradionecrosis in patients with head and neck cancer treated with radiation therapy: isoo-mascc-asco guideline 1. Understanding these classifications helps surgeons choose the optimal flap for reconstruction, considering factors like tissue bulk needed, functional requirements, and aesthetic outcomes, ultimately guiding preoperative planning and intraoperative decision-making in reconstructive surgery.

From the Research

Classification of Free Flaps

Free flaps can be classified into several types based on their composition and blood supply. The main types of free flaps include:

• Fasciocutaneous flaps: These flaps consist of skin and fascia, and are often used for soft tissue reconstruction 2, 3, 4, 5.
• Musculocutaneous flaps: These flaps consist of muscle and skin, and are often used for reconstruction of defects that require bulk and coverage 3, 4, 5.
• Osteocutaneous flaps: These flaps consist of bone, skin, and fascia, and are often used for bony reconstruction 2, 4, 6.
• Perforator flaps: These flaps are based on perforating blood vessels that supply the skin and fascia, and are often used for soft tissue reconstruction 4.

Characteristics of Each Type of Flap

Each type of flap has its own characteristics and advantages:

• Fasciocutaneous flaps are suitable for defects requiring facial contouring or complex skull base defects 2.
• Musculocutaneous flaps are often used for reconstruction of defects that require bulk and coverage, but may have higher rates of flap necrosis and donor-site complications compared to fasciocutaneous flaps 3, 5.
• Osteocutaneous flaps are acceptable options for patients with comorbidities requiring bony reconstructions, and can be used for mandibular reconstruction 2, 6.
• Perforator flaps have been shown to have similar outcomes to other types of flaps, and can be used for soft tissue reconstruction 4.

Selection of Flap Type

The selection of flap type depends on the defect characteristics and reconstructive needs:

• The type of flap to be selected depends on the anatomical structures and size of the defect to be restored 6.
• Flap selection should be guided by defect characteristics and reconstructive needs, rather than by the type of flap alone 5.