Congenital and Acquired Symmastia: What It Is and How to Correct It

• July 23, 2025
• By Fernando Amato

This article addresses the topic of congenital and acquired symmastia, clarifying its characteristics and differences.

Article written with AI assistance and reviewed by Dr. Fernando Amato

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🔍 What is Symmastia?

Symmastia is a condition in which the breasts lose their natural separation, joining at the midline over the sternum. However, the normally well-defined intermammary sulcus becomes absent or imperceptible, creating a “uniboob” appearance.

This alteration can be classified as:

• Congenital symmastia: present from birth
• Acquired symmastia: developed throughout life, often after surgeries

Both forms can therefore compromise the patient's aesthetics and self-esteem, and are frequently corrected by specialized plastic surgery.

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🌟 Important Highlights about congenital and acquired symmastia

• 🧬 Can be congenital, due to embryonic development alterations
• 💉 Or acquired, usually after surgery with breast implants
• 🧾 Diagnosis is clinical, based on physical examination
• 🛠️ Treatment almost always requires corrective surgery
• 🧘‍♀️ Correction must, however, respect breast symmetry and aesthetics

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🧬 Congenital Symmastia

Congenital symmastia is, however, a rare anomaly, originating from failures in the embryological development of the chest wall. However, it can occur in isolation or associated with genetic syndromes, such as Poland syndrome.

Anatomical characteristics

• Hypertrophy of adipose or fibroglandular tissues over the sternum
• Presence of fibrous bands in the midline
• Chest wall deformities

Diagnosis

• Based therefore, on physical examination: the breasts are joined at the midline
• However, it can be confused with medial hypertrophy or narrow chest
• In doubtful cases, imaging exams help to delimit structures

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🩺 Acquired Symmastia

The acquired form is more common and generally occurs as a complication of breast augmentation, when:

• There is excessive dissection of the medial area when placing implants
• Post-operative hematomas or seromas develop
• There are healing failures, with formation of a medial pseudopocket

Additional causes

• Chest trauma
• Radiotherapy or infection
• Extrusion or capsular contracture of implants

Classification of Acquired Symmastia (Zienowicz)

• Mild: breast approximation
• Moderate: partial coalescence
• Severe: complete fusion and absence of sulcus

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🛠️ Treatment of Symmastia

Congenital Symmastia

Treatment is therefore surgical, with aesthetic and functional objectives:

• Removal or repositioning of glandular tissue
• Reconstruction of the intermammary sulcus with fixation sutures to the sternum
• Careful dissection of pre-sternal fat

Thus, each case requires individual planning, especially when there are associated thoracic alterations.

Acquired Symmastia

Management is surgical and personalized:

• Recreation of the sulcus using transsternal sutures
• Exchange or repositioning of implants
• Resection of fibrous capsules if contracture is present
• In severe cases, use of biological or synthetic meshes for reinforcement

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🎯 Aesthetic Aspects of Correction

Symmastia can, however, deeply affect self-image. Thus, surgical correction aims to restore:

• Natural separation of the breasts
• Breast symmetry
• Thoracic proportion
• Harmony between areolas and midline

The approach must also consider breast volume, skin elasticity, and history of previous surgeries.

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❓ FAQ — Frequently Asked Questions

1. What is symmastia?
   It is the fusion of breast tissues in the midline, without separation between the breasts.
2. Is symmastia common?
   The congenital form is rare; the acquired form is more common in patients with implants.
3. What is the main cause of acquired symmastia?
   Excessive dissection during breast augmentation.
4. Can symmastia be prevented?
   Yes, with appropriate surgical technique and post-operative care.
5. Does symmastia hurt?
   Generally, it does not cause pain, but it can cause aesthetic and emotional discomfort.
6. How is surgical correction performed?
   By skin fixation to the sternum and possible exchange or repositioning of implants.
7. Does the surgery leave visible scars?
   The scars are discreet and strategically positioned.
8. Can it recur after correction?
   Rarely, if the techniques are well executed.
9. What is the recovery time?
   About 2 to 4 weeks, with the use of a thoracic binder.
10. Does symmastia interfere with breastfeeding?
    Depends on the previous surgical technique; generally, it does not affect it.

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📢 Schedule an Evaluation

In short, if you notice fusion between your breasts or have had complications after breast surgery, schedule a consultation with a specialized plastic surgeon. Symmastia, therefore, has a solution and can restore self-esteem and harmony to your chest contour.

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