Don Steve
A flap is a unit of tissue that is transferred from one site of the body (donor site) to another (recipient site) while maintaining its own blood supply. Flaps can consist of skin, muscle, fat, or a combination of these tissues and are used in reconstructive surgery to repair defects, cover wounds, or enhance aesthetic appearance. The vascularity of the flap is crucial for its survival post-surgery, as it relies on an intact blood supply to ensure proper healing and integration into the recipient site.
Differentiating between flap & graft.
A flap differs from a graft in that it is transferred with its blood supply intact. This means the flap maintains its own vascularization during and after the transfer. In contrast, a graft is a transfer of tissue without its own blood supply; therefore, the survival of the graft depends entirely on the blood supply from the recipient site.
Classifying flaps according to blood supply, site, type of tissue and geometry.
1. Blood Supply
- Arterial flap: Based on a specific artery and may include several tissue layers. Subclassified as axial, perforator, or free flap.
- Axial flap: Blood supply from a named artery running in the subcutaneous tissue superficial to muscle (e.g., supratrochlear artery for the paramedian forehead flap).
- Perforator flap: Blood supply from a named artery that perforates a muscle to reach overlying tissues (e.g., deep inferior epigastric artery for the DIEP flap).
- Free flap: The artery and vein are cut, and the flap is moved to another anatomical region and reconnected using microsurgery (e.g., ALT flap for lower leg reconstruction).
- Random flap: Blood supply based on interconnecting subdermal plexuses derived from deeper musculocutaneous arteries.
2. Site
- Local flaps: Tissue is transferred from an adjacent area.
- Regional flaps: Tissue is transferred from a nearby but not adjacent area.
- Distant flaps: Tissue is transferred from a remote site on the body.
3. Type of Tissue
- Skin flaps:
- Random skin flap: Consists of skin and subdermal tissue with blood supply depending on random subdermal plexuses (e.g., nasolabial flap).
- Direct cutaneous arterial flap (axial): Consists of skin, subdermal plexuses, and based on a named subcutaneous artery running parallel to the skin (e.g., paramedical forehead flap).
- Composite flaps:
- Fasciocutaneous flap: Contains skin, subdermal tissue, and fascia; can be axial or perforator.
- Musculocutaneous flap: Contains skin, subdermal tissue, and muscle; can be axial or perforator.
4. Geometry
- Rotation flaps: Rotated around a pivot point to cover defects.
- Transposition flaps: Moved laterally to cover adjacent defects without rotation.
- Advancement flaps: Moved directly forward into the defect without rotation or lateral movement.
Identifying the Indications of flaps.
Flaps are indicated for:
- Covering large defects where primary closure or grafts are not feasible.
- Providing bulk to fill cavities or contour deformities.
- Reconstructing areas with poor vascularity where grafts would fail.
- Restoring function by transferring functional muscle units (e.g., in facial reanimation).
- Covering exposed critical structures like bones, tendons, or nerves.
The Care of the flap.
Care for a flap includes:
- Ensuring adequate perfusion by monitoring color, temperature, capillary refill time, and Doppler signals if applicable.
- Avoiding pressure on the flap to prevent compromised blood flow.
- Keeping the patient well-hydrated and maintaining optimal systemic conditions like oxygenation and normothermia.
- Preventing infection through sterile techniques and appropriate antibiotic use if necessary.
- Monitoring for signs of complications such as hematoma formation, seroma formation, or necrosis.
Define free flap?
A free flap is a type of flap surgery where tissue along with its blood vessels is completely detached from its original location (donor site) and then reattached at a new location (recipient site) using microsurgical techniques to connect arteries and veins.
Tissue expander, principle on which it works and indications.
A tissue expander is an inflatable medical device used to stretch skin and soft tissues before reconstructive surgery. It works on the principle of controlled mechanical stretching; when gradually inflated over time with saline solution, it causes surrounding tissues to expand due to cellular proliferation and increased extracellular matrix production.
Indications for tissue expanders include:
- Breast reconstruction post-mastectomy
- Reconstruction following trauma or burn injuries
- Correction of congenital deformities
- Scar revision
“Z” plasty, its principle, uses and advantages.
- Principle: The principle behind Z-plasty involves creating two triangular flaps by making incisions in a Z-shaped pattern. These flaps are then transposed to change tension lines within scarred or contracted areas.
- Uses:
- Lengthening contracted scars
- Realigning scar direction to follow natural skin creases
- Improving functional mobility in joints affected by contractures
- Advantages:
- Reduces tension across scars
- Improves cosmetic appearance by breaking up straight-line scars
- Enhances functional outcomes by increasing range of motion
