Symmastia is when breast implants are too close together and cross the midline of the chest. In extreme cases, the skin is pulled away from the sternal bone, allowing the right and left breast implant pockets to touch, creating a “uniboob.”
Symmastia occurs when the breast implant pocket extends beyond the desired medial contour of the breast. This can occur for a variety of reasons. One of the most common is using an implant that is too large for the patient’s anatomy. If the breast implant is too wide, the implant may extend over the sternum creating this deformity. Too large of an implant in tight-skinned patients can actually pull the skin away from the chest bone. In some cases, the patient’s anatomy is a set up for symmastia. Those with concave chest bones are especially at risk since the breast implants tend to shift toward the center. Others have very mobile skin in the midline and lack the normal attachments to the sternum. Symmastia can also occur if the surgical dissection was extended too far medially or if the surgeon divided the pectoral muscle too high. These well-intentioned attempts to “increase cleavage” lead to over-dissection and symmastia.
Correction of symmastia can be tricky. The basic principle involves revising the pocket to prevent breast implant movement across the midline. Dr. Ciaravino commonly uses a capsulorraphy technique that involves placing permanent sutures into the capsule layer along the medial breast contour. In some instances, these sutures are placed directly into the bone. The breast pocket is also modified laterally to improve implant position. Proper selection of the new breast implant based on dimensional analysis of the patient’s anatomy is important. Frequently, this involves using a slightly smaller or narrower implant. In patients with sub-glandular breast implants, converting to a sub-pectoral position (under the muscle) may correct the symmastia. Extreme cases may require more involved reconstructive techniques such as the use of acellular dermal matrix (Strattice). Post-operative taping and compression garments are commonly used.
Dr. Ciaravino has treated many patients with symmastia and has great success repairing this challenging problem.