Prepectoral vs Subpectoral Breast Reconstruction: Implant Above or Under the Muscle – Which Is Better for You?
Both options are well established. A breast implant can be placed above the large chest muscle (prepectoral) or under it (subpectoral). Neither position is better in every case. What suits you depends on the quality of your skin, the size of your breast, any radiation therapy and your own wishes.
In this article
What do prepectoral and subpectoral mean?
The chest wall is built up in layers. On the outside is the skin, with a layer of fat underneath. Then comes the large chest muscle (pectoralis major). It lies flat against the ribs. During a mastectomy, the breast gland tissue between the fat and the muscle is removed. That is where the space for the implant is created.
Prepectoral: the implant sits in front of the muscle, directly under the skin and fat. The muscle stays where it is.
Subpectoral: the muscle is released along its lower edge and lifted. The implant sits in a pocket under the muscle. The lower part is often covered only by skin or by a mesh.
How does implant-based breast reconstruction work?
Implant-based reconstruction starts with the mastectomy. Today the skin is often preserved. In a skin sparing mastectomy, the skin envelope of the breast is kept. In a nipple sparing mastectomy, the nipple and areola are kept as well. Small incisions are often enough for this, for example in the breast fold or at the side.
After that there are two routes. With immediate reconstruction, the final implant is placed during the same operation. This is possible when enough healthy skin remains. With the two-stage route, a tissue expander is placed in the pocket first. It is filled slowly over several weeks and stretches the skin. Later it is exchanged for the implant. Both routes are possible above or under the muscle.
You can read more in the article Tissue Expander and Implant-Based Breast Reconstruction: A Complete Guide.
Prepectoral: pros and cons of an implant above the muscle
In prepectoral reconstruction the muscle is not touched. This has advantages:
The muscle is not stretched or released. Many women therefore have less pain in the beginning.
The breast does not move along when you tense your chest muscle. This movement is called animation deformity.
The breast falls and moves more naturally, because it is not attached to the muscle.
There are also disadvantages, because only a thin layer of tissue lies between the implant and the skin:
The edge of the implant may be visible or easy to feel, especially in slim women.
Rippling can occur. This means that folds of the implant show through the skin.
The skin envelope must have a good blood supply and be thick enough. Otherwise the risk of wound problems is higher.
A mesh or an acellular dermal matrix (ADM) is often used to support the implant.
Visible edges and rippling can often be improved later by placing your own fat under the skin (lipofilling).
Subpectoral: pros and cons of an implant under the muscle
In subpectoral reconstruction the muscle lies over the implant like an extra blanket. For a long time this was the usual approach.
More tissue covers the implant. The edge is less visible, and rippling is less noticeable.
If the skin has problems after the operation, the muscle protects the implant from becoming exposed.
Here too there are disadvantages:
When you tense the muscle, the implant can distort or slide upwards (animation deformity). Some women find this bothersome during sport or in daily life.
The muscle is stretched. In the first weeks, pain and a feeling of tightness are often stronger.
The body forms a thin capsule around every implant. If it becomes hard and painful, this is called capsular contracture. Whether the position of the implant affects this risk is still being debated by specialists.
Mesh or acellular dermal matrix (ADM): what is it for?
An acellular dermal matrix (ADM) is processed donor or animal skin from which all cells have been removed. A mesh is a fine synthetic fabric. Both are slowly grown through by your own tissue.
With a prepectoral implant, the material often wraps around the whole implant and slightly reinforces the skin cover. With a subpectoral implant, it is usually used only at the bottom, where the muscle does not cover the implant. There it forms a kind of hammock.
Using these materials is not standard everywhere. Some studies saw more fluid collections (seromas) or infections, others saw no difference. Ask whether your team uses a mesh or an ADM, and why.
Radiation therapy and implant position
Radiation therapy changes the skin and tissue of the chest wall. The skin often becomes firmer, thinner and less well supplied with blood. Wound problems and a hard capsule are then more common, with both implant positions.
If the skin is thin after radiation, the muscle may offer extra protection. If the skin is in good condition, a prepectoral position is possible. If radiation is still to come, an expander is sometimes placed first and the final implant only afterwards.
Read more in the article How Radiation Therapy Affects Your Breast Reconstruction Options.
Who is suited to which position?
There is no fixed rule. During the operation your team checks how good the blood supply to the skin is, and decides together with you. These points play a role:
Skin quality: a thick skin envelope with a good blood supply favours prepectoral. Thin or irradiated skin tends to favour subpectoral.
Body build: in very slim women, an implant above the muscle is more easily visible.
Radiation: previous or planned radiation therapy influences the choice and the timing.
Activity and wishes: women who do a lot of sport, or who want to avoid movement of the breast, often choose prepectoral.
Experience of the clinic: ask which method your team uses regularly.
Recovery compared
After both operations you usually stay in hospital for a few days. Drains are removed after about one to two weeks. In the first weeks you should not lift your arm above shoulder height and should not carry anything heavy.
After a prepectoral reconstruction, many women report less pain, because the muscle was not stretched. After a subpectoral reconstruction, the feeling of tightness is stronger at first and usually eases within a few weeks. You start sport and lifting after discussing it with your team, usually after about six weeks.
Switching from subpectoral to prepectoral
Do you have an implant under the muscle, and does the movement when you tense the muscle bother you, or do you have lasting pain? Then changing the position is possible. The muscle is laid back onto the chest wall, and the new implant is placed in front of the muscle. The skin cover is often strengthened with your own fat or a matrix.
Such a switch is an operation with its own risks. It only makes sense if the complaints really trouble you. Sometimes smaller measures, such as lipofilling, also help.
Alternatives using your own tissue
An implant is not the only way. The breast can also be rebuilt from your own tissue, usually skin and fat from the lower belly (DIEP flap). This tissue usually copes better with radiation and feels soft. On the other hand, the operation is longer and recovery takes more time.
You will find a comparison in Breast Implant or DIEP Flap? An Honest Comparison and in the article DIEP Flap Breast Reconstruction: Using Your Own Abdominal Tissue.
Frequently asked questions
What is prepectoral breast reconstruction?
In prepectoral reconstruction the implant sits in front of the large chest muscle, directly under the skin and fat. The muscle is left untouched, and the breast does not move when you tense the muscle. This method needs a skin envelope with a good blood supply.
What does it mean to have a breast implant under the muscle?
The large chest muscle is released along its lower edge and lifted over the implant. This puts more tissue between the implant and the skin. The trade-off is that the breast can move when you tense the muscle.
Who is a good candidate for an implant above the muscle?
Placing the implant above the muscle works best when the skin after the mastectomy is thick enough and has a good blood supply. If the skin is very thin, placing the implant under the muscle may be safer. Your team judges this during the operation.
What is implant-based breast reconstruction?
The breast shape is rebuilt with a silicone or saline implant. No tissue is taken from another part of your body. The implant can be placed above or under the muscle.
What is a skin sparing mastectomy?
In a skin sparing mastectomy the breast gland tissue is removed, but as much skin as possible is kept. This skin envelope is filled straight away with an implant or a tissue expander. The shape and size of the breast are largely preserved.
Can a mastectomy be done through small incisions?
Yes. With a skin sparing or nipple sparing mastectomy, small incisions are often enough, for example in the breast fold or at the side. Whether this is possible for you depends on where the tumour is and on the size of your breast.
Is implant reconstruction possible after radiation, and where does the implant go?
It is possible, but irradiated skin is often less stretchy and has a poorer blood supply. This raises the risk of wound problems and a hard capsule. Your team will discuss with you whether an implant above or under the muscle makes sense, or whether your own tissue is a better fit.
Can an implant be moved from under the muscle to above the muscle?
Yes. Switching from subpectoral to prepectoral is possible if you have complaints, such as bothersome movement of the breast or lasting pain. The muscle is laid back onto the chest wall. The skin cover is often strengthened with your own fat or a matrix.
Questions to ask your surgeon
Which implant position do you recommend for me, and why?
How do you judge my skin quality after the mastectomy?
Do you use a mesh or an ADM? What does that mean for me?
How would radiation therapy affect the choice?
What can I do if I am not happy with the position later on?
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Written by Dr. Mahyar Foumani, plastic and reconstructive surgeon specializing in breast reconstruction. Based on the book 'Breast Reconstruction Explained.'
This article is education, not medical advice
This article explains in plain words how breast reconstruction works. It is meant to help you understand what is possible, so that you and your doctor can make a good decision together. It does not replace personal medical advice.
Every situation is different. What is best for you depends on your body, your illness, your treatment and your own wishes. So always follow the advice of your own doctor or care team. Do you have symptoms, or are you unsure about something? Please contact your doctor or GP. In an emergency, call your local emergency number.
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