Symmastia: Causes, Prevention and Treatment

Symmastia is a rare condition marked by the apparent fusion of the breasts. This can make it appear as though the breasts have merged with one another. Women who have symmastia can schedule a consultation with a board certified plastic surgeon to have the condition corrected.

Causes of Symmastia

Symmastia occurs when the breasts converge. It can be caused by a congenital condition or, more commonly, as a side effect of breast augmentation. In patients who undergo breast augmentation, symmastia is more likely to occur if:

• Large breast implants are improperly placed and the connective tissues over the sternum are weakened, symmastia can occur.
• The patient is petite and has larger sized implants placed.
• The pockets in which the implants are placed are positioned too close to the midline of the chest.
• Subglandular implants (above the muscle implants) are placed as opposed to submuscular implants (those that are placed underneath the pectoral muscles). Still, symmastia can occur with under the muscle implants when the implant in misplaced and the muscles put pressure on one or more of the implants, moving them toward the center of the chest.

The malpositioning of the implants can happen in one or both breasts.

Prevention of Symmastia

By skillfully performing the proper breast augmentation techniques and choosing a surgical approach that best fits the patient’s needs and body type, the risk of symmastia can be reduced. 

It is critically important that patients select the appropriate shape, size, and profile implant for their body. Selecting implants that are too large or too wide increases the risk of symmastia. This should not discourage patients from selecting a larger implant, as appropriate placement by a trained cosmetic surgeon generally prevents the development of symmastia. 

The surgeon must be sure to place the implants in the correct place. It the implants are too close to the middle of the chest, the implants can wear the soft tissues. Appropriate placement comes with years of training and experience; the surgeon should understand how the implants settle over time to create the desired profile and cleavage.

The pocket that the implant is placed in must be the perfect size; not too big or too small. Certain incision techniques, such as the inframammary and areolar methods, make it easier to create the implant pocket and place the implant. Patients who choose the transaxillary or transumbillical incision options should be sure that the surgeon is skilled enough to perform these techniques. 

Choosing to place the implants underneath the pectoral muscle also helps to prevent symmastia. The muscles act as a buffer and keep the pockets from expanding.

There are sternum compression bras that keep the breasts separate and help prevent the development of symmastia. Wearing these compression bras after a breast augmentation can help to prevent the soft tissues on the chest from wearing, which is what causes the skin over the sternum to lift, causing the “uniboob” effect.

Treating Symmastia

The only treatments for symmastia are breast implant revision surgery. If the implants were placed above the chest muscle, they may need to be taken out and placed under the muscle. If the implants are already beneath the muscle, the muscles may need to be sutured near the sternum and under the breasts to ensure symmastia does not reoccur. In some cases, Alloderm or Strattice Regenerative Tissue Matrix can be used to create a barrier between the breast implants; this prevents the implants from moving toward the center of the chest. 

Contact Crawford Plastic Surgery to learn more about symmastia treatment options.