A flap is tissue moved from one place to another keeping its own blood supply. Unlike a graft, it arrives alive and does not depend on the bed to survive.
When a wound leaves bone, tendon, cartilage, a joint or a prosthesis exposed, a skin graft is no use: a graft needs a bed to feed it during the first days, and those structures do not. That is where a flap is needed, that is, tissue that travels with its own vascular pedicle and arrives with a blood supply from the first moment. It is also used when the result matters — on the face above all — because a local flap brings skin of very similar colour and texture to the area being reconstructed.
Nobody comes to the consultation asking for a flap: it is a technique, not a goal. It appears when there is a defect to solve, and its particular name — advancement, rotation, perforator, free — describes where the tissue comes from and how it gets there. What is worth knowing is what it involves: a longer operation, an additional scar where the tissue is taken from, and a first few days in which monitoring the blood supply is the most important part of the whole treatment.
It usually helps when there is
- A defect with bone, tendon, cartilage or a joint exposed.
- Exposure of prosthetic or fixation material.
- A chronic wound that will not close despite proper treatment.
- Facial reconstruction where colour and texture matter.
- An irradiated or poorly vascularised bed, where a graft will not take.
Worth discussing first if
- Current smoking: the factor that most compromises survival.
- Peripheral vascular disease or poorly controlled diabetes.
- General health that will not tolerate a prolonged operation.
- Active uncontrolled infection of the bed.
- A simpler alternative that solves the problem equally well.
None of these rules the procedure out on its own; all of them change the conversation.
Where the tissue comes from
Distance and complexity increase as you climb the reconstructive ladder.
Local flap
Neighbouring tissue is shifted, rotated or advanced to cover the defect. It gives the best result on the face: same colour, same texture.
Regional flap
Tissue from a nearby area that arrives keeping its original pedicle. It covers larger defects with no need for microsurgery.
Free flap
The tissue is detached completely and reconnected to the vessels of the recipient area with microsurgery. It resolves defects no other technique covers.
The simplest option that solves it well
The reconstructive ladder orders the options from least to most complex, and you climb only as far as necessary. A free flap that was not needed adds hours of surgery, a larger donor scar and a risk that is not justified. The reverse is a mistake too: forcing a direct closure under tension on a defect that called for a flap ends in wound breakdown.
The design is based on the vascular anatomy. Before raising any flap, the pedicle that will feed it is identified, and in perforator flaps it can be located with Doppler. That pedicle is protected throughout the operation: it is the life of the transferred tissue.
The donor area is part of the planning from the start, not an afterthought. It is chosen so that its scar stays hidden and its functional loss is minimal, because the patient will live with it just as they live with the reconstructed area.
What the process is like
The monitoring of the first days is the most important part.
Planning
The defect is studied, the flap is chosen and its vascular pedicle located. The scar at the donor site is explained.
Surgery
The flap is raised protecting its blood supply, moved to the defect and the donor area closed. In free flaps the vessels are reconnected with microsurgery.
Monitoring
The first three to five days are critical: the colour, temperature and refill of the flap are checked. A problem picked up in time can be corrected.
Consolidation and adjustments
The flap integrates over the following weeks. Months later, contour touch-ups can be done, because it usually ends up slightly bulkier than the neighbouring area.
What to expect
These are general timings; a local flap on the face recovers far sooner.
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Days 1 to 5
The critical period. Close monitoring of the blood supply, rest for the area, avoiding pressure on the flap and sometimes a required position.
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Weeks 1 to 3
The flap settles and the stitches come out. Gradual mobilisation begins, with physiotherapy if the area needs it.
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Weeks 4 to 12
The donor area finishes healing. The flap softens and starts to blend in texture with the neighbouring skin.
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Months 6 to 12
The result is consolidated. Time for contour touch-ups if the flap ended up bulky.
Risks, and what is not promised
The risk specific to this technique is failure of the flap from a compromised blood supply: partial, which leaves an area of necrosis to resolve, or total, which means starting again with a different strategy. In free flaps the typical problem is thrombosis of the pedicle in the first days, and that is why monitoring is so close: reoperating in time saves the flap.
To that are added the general risks — bleeding, haematoma, infection, wound breakdown — and those of the donor area: scarring, altered sensation, seroma and, depending on the flap, some functional loss. The surgery is long and that carries its own anaesthetic and thrombosis risk.
Smoking is the modifiable factor that weighs most: it significantly multiplies the risk of necrosis. It is not promised that the flap will match the neighbouring skin: it usually differs in colour, texture and thickness, and often needs a later touch-up. These risks are reduced by a correct design, strict monitoring and giving up smoking. They are not eliminated. The ones that apply to your case are set down in writing in the informed consent.
The information on this page is for guidance and does not replace an in-person medical consultation. Medical practice is an obligation of means, not of result.
The questions we are asked most about flaps
A graft is skin with no blood supply of its own: it is placed on the defect and survives because the bed feeds it during the first days. A flap arrives with its own artery and vein, alive from the first moment.
That is why a graft is no use over bone, tendon or prosthetic material, which cannot feed it. There a flap is needed.
Yes, always. Every flap reconstruction trades a problem in one place for a scar in another, and that scar is part of the deal.
That is why the donor area is chosen carefully: so that it stays hidden and its functional loss is minimal. It is explained before the surgery, not after.
If the compromise is partial, the necrotic area is removed and resolved with directed wound care or a graft. If it is total, the reconstruction has to be rethought with a different strategy.
It is infrequent when the design is correct and the patient does not smoke, and that is why the first days are watched so closely: picking the problem up early allows reoperation and saves the flap.
Because nicotine constricts the small vessels, which are exactly the ones keeping a flap alive. Smoking significantly multiplies the risk of necrosis.
It is not a lifestyle recommendation: it is the modifiable factor that most influences whether the surgery works. You are asked to stop beforehand and to keep it up afterwards.
Question not answered here? There are more answers in the frequently asked questions.
