Tissue expansion means placing a silicone balloon under the neighbouring healthy skin and filling it little by little, until there is surplus skin with which to replace a scarred area.
Skin has a remarkable capacity to grow when it is stretched slowly and steadily: it is what happens in pregnancy. Tissue expansion makes use of that mechanism. An expander — a silicone balloon with a port — is placed under the healthy skin next to the area to be reconstructed, and each week saline is injected through the port. The skin above it grows, and after a few months there is enough surface to remove the scar and cover the defect with skin of the same colour, the same texture and, on the scalp, with hair.
That is its value: no other technique gives back skin so close to the original, and in scalp reconstruction it has no substitute, because a graft brings no hair. And this is its price, which has to be said up front: for three to six months the patient carries a visible, growing bulge in the expanded area. On the head or the face that is socially difficult, especially in children, and it is the main reason some patients abandon the process halfway. It is worth deciding knowing exactly that.
It usually helps when there is
- An extensive scar or burn sequela with healthy neighbouring skin available.
- An area of scalp without hair from a burn, a scar or scarring alopecia.
- An extensive congenital lesion, such as a giant naevus.
- Breast reconstruction in two stages, before the definitive implant.
- A willingness to go through several months with a visible deformity.
Worth discussing first if
- Not enough healthy skin around the area to be reconstructed.
- Neighbouring skin that is irradiated or of poor quality, which expands badly.
- Difficulty attending weekly for the expansions.
- A school or work situation that makes the visible period very hard.
- Active infection or an open wound in the area.
None of these rules the procedure out on its own; all of them change the conversation.
Where it is used most
It is a technique with a precise indication, not one for general use.
Scalp
Its best indication. It is the only way to give back hair-bearing skin to an area of scarring alopecia: no graft achieves it.
Burn sequelae
It allows a wide scarred area to be replaced with healthy skin of the same colour and texture, instead of a graft that will always show.
Breast reconstruction
The expander prepares the space and the skin for the definitive implant, placed at a second operation months later.
Slow wins
Expansion is done slowly and that is why it works. A small volume is injected each week, checking that the skin does not go tight or pale: if it is forced, the skin suffers, the expander becomes exposed and the process is lost. Rushing the schedule is the most common way to fail.
Placing the expander is planned carefully: a pocket of exactly the right size, the port in a comfortable, accessible position, and the incision sited so that the scar ends up inside the area that will be removed or hidden in the final design.
More is expanded than seems necessary. Expanded skin pulls back part of what was gained once the device is removed, so a deliberate surplus is aimed for; finishing exactly even forces a closure under tension, which is precisely what you were trying to avoid.
What the process is like
Two operations separated by several months of weekly expansions.
Planning
The surface to be reconstructed and the healthy skin available are measured, and the size and shape of the expander chosen. The visible period is explained in detail.
First operation
Placement of the expander under the healthy skin, with the port accessible. It starts with a partial filling.
Expansions
Every week, in the consulting room and without anaesthesia: saline is injected through the port. Tightness for a day or two. It lasts two to four months.
Second operation
The expander is removed, the scar excised and the expanded skin advanced to cover the area. It is the operation that gives the result.
What the process is like to live through
The most demanding part is not the recovery but the months in between.
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Weeks 1 to 2
After the first operation: moderate discomfort and care of the incision. Normal activity with care over the area.
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Months 1 to 4
Weekly expansions. Tightness for a day or two after each filling. The bulge grows and becomes obvious. This is the socially difficult phase.
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Weeks 1 to 3 after the second operation
With the expander removed, the deformity disappears immediately. Dressings and stitches out.
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Months 3 to 12
The final scar matures and lightens. The expanded skin recovers normal thickness and texture.
Risks, and what is not promised
The typical problem is exposure of the expander: the skin above thins excessively, opens and the device is uncovered, which means removing it and losing the process. It happens above all when expansion is too fast or when the starting skin was not good. Infection — which likewise means removing it — haematoma, leakage or failure of the expander and pain during the fillings are also possible.
Deformation of the underlying bone from the pressure can occur, especially in a child's skull; it is generally reversible once the device is removed, but it is a known phenomenon and it is monitored. And there is always the scar from the second operation, although it is designed to stay disguised.
It is not promised that the process will be comfortable: it is three to six months with a visible deformity, and that is the part most patients abandon. Nor is it promised that the whole area will be covered in a single expansion; sometimes two cycles are needed. These risks are reduced by expanding slowly and with weekly reviews. 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 tissue expansion
Yes, and it is worth knowing before starting. For three to six months there is a bulge that grows week by week, and on the head or the face it is hard to disguise.
It is the hardest part of the treatment and the most frequent reason for giving up. It disappears immediately when the expander is removed at the second operation.
The needle into the port is mild and needs no anaesthesia. What is uncomfortable is the tightness of the skin for the day or two after each filling.
If the tightness is intense or the skin looks pale, too much was injected, and the pace is adjusted at the next review. Rushing is never worth it.
Because a graft always shows: a different colour, a different texture and no hair. On the scalp it also brings no hair back, and there expansion has no substitute.
Expansion gives your own skin, of the same colour and texture and with its appendages. It is the best quality of reconstruction in exchange for a long process.
Yes, and in fact it is widely used for childhood burn sequelae because children's skin expands very well.
The difficulty is social: school and the visible period weigh heavily at that age. It is discussed with the family and with the child, and sometimes it is worth scheduling it over the holidays.
Question not answered here? There are more answers in the frequently asked questions.
