Symmastia: Symptoms, Types, Causes and Treatment

Symmastia is a rare yet impactful condition that can dramatically alter the appearance of the chest, leading to both physical and emotional concerns. Whether resulting from congenital factors or acquired after breast augmentation surgery, symmastia is recognized by the merging or confluence of the breasts across the midline, creating the appearance of a web or absence of cleavage. Understanding its symptoms, types, causes, and available treatments can empower patients to seek timely and effective care. This article brings together the latest evidence from medical research to offer a comprehensive and human-centered overview of symmastia and its management.

Symptoms of Symmastia

Recognizing the symptoms of symmastia is the crucial first step in seeking appropriate care. The condition most notably affects the appearance of the chest, but it can also have other physical and psychological impacts. Here, we break down the key features and what to look for.

Symptom	Description	Onset	Source(s)
Medial web	Web-like soft tissue connecting breasts	Congenital or acquired	1, 5, 6
Loss of cleavage	Absence or blurring of natural breast separation	Gradual or sudden	1, 2, 5
Breast confluence	Breasts appear to merge at the midline	Visible	1, 2, 5
Skin changes	Redundancy, dimpling, or puckering over sternum	Variable	5, 6, 7

Table 1: Key Symptoms

Medial Web and Loss of Cleavage

The hallmark sign of symmastia is the formation of a soft tissue web or bridge that crosses the sternum, connecting the breasts medially. This is most striking in congenital cases, where it can be present from birth and varies in severity. In acquired cases, particularly following breast augmentation, the loss of cleavage often develops gradually as the breast implant pockets communicate across the midline, resulting in the breasts appearing to merge 1, 2, 5.

Breast Confluence

Patients may notice that the natural separation between their breasts disappears, and the breasts seem to merge into a single mass, especially over the sternum. This can be distressing cosmetically and may affect clothing choices or self-image 1, 2, 5.

Skin Changes

Other symptoms can include changes in the skin overlying the sternum, such as redundancy, dimpling, or puckering. In some cases, the skin may appear stretched or there could be visible scarring, especially after surgical correction attempts 5, 6, 7.

Psychological Impact

While not a physical symptom, the aesthetic changes caused by symmastia can lead to significant psychological distress, affecting self-esteem and quality of life. Timely recognition and consultation with a specialist are essential to address both the physical and emotional aspects of the condition.

Types of Symmastia

Symmastia is not a one-size-fits-all diagnosis. Understanding its types—congenital and iatrogenic (acquired)—is essential for determining the best course of treatment and setting realistic expectations.

Type	Key Features	Typical Patient	Source(s)
Congenital	Present at birth, web-like tissue across sternum	Young females (rare)	1, 6
Iatrogenic	Develops after breast surgery/augmentation	Adults post-surgery	2, 5, 7

Table 2: Types of Symmastia

Congenital Symmastia

Congenital symmastia is extremely rare and results from abnormal development of the soft tissue between the breasts. It is identified at birth or in early childhood and is characterized by a web-like band of tissue that crosses the sternum, connecting the two breasts 1. This type often presents in young females and can vary from mild to severe.

Key Points:

• Not related to surgery or trauma
• Web-like tissue may contain fat, glandular, or fibrous elements
• Literature and clinical experience are limited due to its rarity 1, 6

Iatrogenic (Acquired) Symmastia

Iatrogenic symmastia is far more common and occurs as a complication of breast augmentation or reconstructive surgery. It is typically caused by over-dissection of tissue during implant placement, allowing the two breast implant pockets to merge across the midline 2, 5, 7.

Key Points:

• Most often seen after subpectoral (beneath the muscle) breast augmentation
• Can occur with both saline and silicone implants
• May develop gradually after surgery or following implant complications 2, 5

Causes of Symmastia

Understanding what leads to symmastia is crucial for both prevention and effective treatment. The causes range from developmental anomalies to surgical mishaps.

Cause	Mechanism	Risk Group	Source(s)
Congenital anomaly	Persistence of web-like tissue over sternum	Infants/children	1, 6
Surgical over-dissection	Disruption of tissue during augmentation	Breast surgery patients	2, 5, 7
Oversized implants	Implants too wide for chest, pressure effects	Breast augmentation	2, 5
Fascia/muscle disruption	Dissection of medial pectoralis/surgical error	Surgery patients	2, 5, 7

Table 3: Causes of Symmastia

Congenital Causes

Congenital symmastia is caused by abnormal persistence of a web-like band of soft tissue that traverses the sternum, connecting the two breasts. This tissue may contain fat, glandular, or fibrous elements and is a developmental anomaly rather than a result of trauma or surgery 1, 6.

Iatrogenic (Acquired) Causes

The majority of symmastia cases are acquired, most commonly after breast implant surgery:

• Surgical Over-dissection: The most frequent cause is over-dissection of the implant pocket medially during subpectoral augmentation, leading to disruption of the natural attachments between the skin, fascia, and sternum 2, 5, 7.
• Oversized Implants: Using implants that are too wide for the patient’s chest can exert excessive pressure on the midline tissues, stretching or disrupting the natural barriers 2, 5.
• Fascia or Muscle Disruption: Excessive dissection or division of the medial attachments of the pectoralis major muscle or sternal fascia can result in implant pockets merging across the midline 2, 5, 7.

Risk Factors

• Subpectoral (under the muscle) augmentation is associated with a higher risk due to the proximity of the surgical plane to the sternum 2.
• Aggressive surgical technique or lack of attention to midline anatomy increases the chance of developing symmastia 2, 5.

Treatment of Symmastia

Treating symmastia is complex and highly individualized, depending on the underlying cause, severity, and patient preferences. Both non-surgical and surgical approaches are employed, with surgery being the mainstay for most patients.

Treatment	Method/Approach	Best For	Source(s)
Reduction mammaplasty	Surgical reduction of breast tissue	Congenital cases	1
Liposuction	Removal of excess fat in presternal web	Congenital, mild cases	1, 6
Capsulorrhaphy	Suturing implant capsule to re-create pocket	Iatrogenic, implant cases	2, 5, 7
Neosubpectoral pocket	Creating new implant pocket	Recurrent/complex cases	4, 7
Transcutaneous suturing	Suturing tissue to sternum	Iatrogenic	5, 6
Allogenic grafts/glues	Tissue reinforcement	Complex/revision cases	5

Table 4: Treatment Approaches

Non-Surgical and Minimally Invasive

For certain mild or congenital cases, less invasive treatments can be considered:

• Liposuction: Suction-assisted removal of fat from the presternal web can help contour the area and minimize the visible band, particularly in congenital cases without significant glandular tissue 1, 6.
• Periareolar Approach: Using discrete incisions around the areola to access and repair the intermammary space, minimizing visible scarring 6.

Surgical Treatments for Congenital Symmastia

• Reduction Mammaplasty: Surgical reduction and reshaping of the breast tissue to correct the abnormal confluence and re-establish the natural medial border 1.
• Combination Procedures: Often, a combination of liposuction, tissue excision, and skin re-draping is needed to fully correct congenital symmastia 1, 6.

Surgical Treatments for Iatrogenic Symmastia

Treatment for acquired (post-surgical) symmastia is more complex and often requires advanced surgical intervention:

• Capsulorrhaphy: Involves suturing the implant capsule to close the abnormal pocket and re-create natural cleavage. Both medial and posterior capsular flaps may be used to reinforce the repair 2, 5, 7.
• Neosubpectoral Pocket Creation: A newer technique where a new pocket is created between the pectoralis major muscle and the anterior implant capsule, relocating the implant and preventing recurrence. This approach is particularly useful in recurrent or complex cases, offering more reliable results 4, 7.
• Transcutaneous Suturing: Sutures are passed through the skin to anchor the presternal soft tissue to the sternum periosteum, reinforcing the midline and preventing web formation. This method can be combined with capsulorrhaphy for greater efficacy 5, 6.
• Allogenic Grafts or Tissue Glues: In select complex or revision cases, biological or synthetic materials can be used to reinforce the repair and promote tissue integration 5.

Postoperative Considerations

• Implant Selection: Avoidance of oversized implants is critical to prevent recurrence; implants should match the patient’s chest width and anatomy 5.
• Supportive Garments: Applying external compression or support after surgery helps maintain the repair and reduce stress on healing tissues 2, 5.
• Staged Procedures: In some cases, a two-stage repair may be recommended, especially if the tissue is thinned or damaged, allowing for optimal healing before reimplantation 7.

Conclusion

Symmastia presents a unique challenge in both its diagnosis and treatment. Whether present from birth or acquired after breast surgery, it can have a profound aesthetic and psychological impact. Here’s a summary of the key points:

• Symptoms: Symmastia is marked by a web-like tissue connecting the breasts, loss of cleavage, and skin changes over the sternum 1, 5, 6.
• Types: Two main types exist—rare congenital forms and more common iatrogenic forms following breast augmentation 1, 2.
• Causes: Congenital cases result from developmental anomalies, while acquired cases are most often due to surgical error, particularly over-dissection or oversized implants 1, 2, 5.
• Treatment: Management is individualized, with options ranging from liposuction and reduction mammaplasty for congenital cases to advanced surgical techniques like capsulorrhaphy and neosubpectoral pocket creation for iatrogenic cases 1, 2, 4, 5, 6, 7.

In summary:

• Early recognition and appropriate intervention are key to successful outcomes.
• Prevention through careful surgical technique and appropriate implant selection is paramount in iatrogenic cases.
• Surgical correction, while complex, can restore normal breast contour and improve quality of life for affected individuals.

If you suspect you have symmastia, consulting with a board-certified plastic surgeon experienced in breast reconstruction is essential to determine the best treatment plan tailored to your individual needs.