In free-flap reconstruction techniques, areas of fat and skin, with or without muscle, from one part of the body are moved to another. The blood vessels supplying the flap are cut and then reconnected to the blood vessels in the armpit or under the breast bone so a new blood supply is created. These techniques involve using microsurgery (joining arteries and veins that are only 2–3mm in diameter, using an operating microscope).

This is specialised surgery and is carried out by surgeons who are experienced in these procedures. Even surgeons who carry out microsurgery may specialise in only one or two microsurgery techniques.

This uses the same skin and fat from the lower abdomen as the pedicled TRAM flap, but less muscle is taken. Once the blood vessels are joined up, the blood supply tends to be better than the pedicled TRAM flap. It is possible to reconstruct a larger breast using this technique and the appearance is usually very good. However, some muscle is still taken from the abdominal wall and it is still necessary to repair it with mesh to prevent hernias and bulges.

This is a bigger operation with a greater risk of complications and a longer recovery time. The operation usually takes at least 6–8 hours and because a part of the rectus abdominis muscle is used, there is a risk of abdominal hernia in up to 11 out of every 100 women who have this type of reconstruction.

The main complication of this operation is that the flap of tissue may not get enough blood supply. If this happens all or some of it will die. This occurs in up to 5–10 out of every 100 women who have this type of surgery. When flaps fail (totally or partially), you will need to wear long-term dressings until it heals completely. Your surgeon will then advise you about your options.

As with the pedicled flap, it may not be a suitable operation for women who are diabetic, heavy smokers or very overweight. It may also not be suitable for women who have had certain types of abdominal surgery previously.

Free perforator flaps are flaps of skin and fat with an attached artery and vein for blood supply. No muscle is taken so, if the flap is taken from the abdomen, there is much less chance of weakness or hernia; and a mesh (as described previously) does not need to be used. Free perforator flaps take 6–8 hours or more to do and need a hospital stay of about a week or longer. It may not be a suitable operation for women who are diabetic, heavy smokers, very overweight or who have had previous abdominal surgery.

As described above (in relation to the free TRAM flap), there is a chance that the tissue in the area may die if the blood supply to the new breast is not good enough. This occurs in 5–10 out of every 100 women who have this procedure. Even when performed by experienced surgeons some of the flap or the whole flap may die. Long-term dressings may be needed until the area has completely healed. Your surgeon will then advise you about your options.

There are several types of perforator flaps and they are named after the blood vessels used. The most common flaps that are taken from the abdomen are the free DIEP flap (Deep Inferior Epigastric Perforator flap) and the free SIEA flap (Superficial Inferior Epigastric Artery flap) as described below.

Free DIEP flap and free SIEA flap

In these procedures, skin and fat is taken from the lower abdomen but without any muscle. The muscle through which the blood vessels come is left in the abdomen. The tiny blood vessels that keep the skin and fat alive are very carefully cut out as far as the larger artery and vein in the groin (the deep or the superficial inferior epigastric perforators). The flap of skin and fat is then moved to the chest and the blood vessels joined to blood vessels of the same size in the armpit or chest wall.

The appearance of the new breast is usually very good and feels very natural. The risk of hernias or bulges in the abdomen is almost completely removed because no muscle is taken, so a mesh does not need to be used.

The main advantage of this type of flap is that no muscle is removed and so recovery is quicker than with the TRAM flap and there should be no abdominal weakness. However, it is a more complicated operation and needs to be done by an experienced surgeon. There is also a greater risk that all or part of the flap will die than with a simple free TRAM flap.

Other free perforator flaps

There are several other free perforator flaps that can be considered. These include the free SGAP flap (Superior Gluteal Artery Perforator flap) and the free IGAP flap (Inferior Gluteal Artery Perforator flap) as described below.

At the time of writing, in the UK these types of reconstruction are less commonly carried out than the other types described earlier in this section. Your surgeon will help you to decide what type of operation would suit you best.

Free SGAP flap and free IGAP flap - Here fat and skin is taken from the upper or lower buttock to create a new breast. The breast produced from the IGAP flap is softer than the one from the SGAP flap. Also with the IGAP flap, larger breast sizes may be created, and the scar easily hidden by underwear because it is in the buttock crease. For these reasons, the IGAP flap may become the most common flap from the buttock area in the future. It is generally used when tissue from the abdomen cannot be used due to scarring from previous surgical procedures, or because the patient is too slim.

In rare cases, it may be possible to take free perforator flaps from other places, where there is enough fat and a suitable blood supply.