What is a Seroma?
A seroma is a collection of serous fluid that accumulates beneath the skin or in a surgical cavity following tissue dissection or surgery, most commonly occurring after procedures involving extensive undermining or dead space creation.
Definition and Pathophysiology
A seroma represents the accumulation of clear, straw-colored serous fluid in a potential space created during surgery 1. This fluid collection develops when lymphatic vessels and small blood vessels are disrupted during surgical dissection, leading to fluid leakage into the surgical cavity 2, 3.
The exact pathophysiology remains incompletely understood, but the primary contributing factor is the creation of dead space during surgical dissection 2, 3. The fluid composition suggests it may be either lymph-like fluid from disrupted lymphatic channels or inflammatory exudate from the surgical trauma 3.
Clinical Context and Timing
Seromas typically develop within the first week after surgery, though they can occasionally present as "late seromas" occurring beyond this expected timeframe 4. The condition is characterized by:
- Visible or palpable fluctuant swelling at the surgical site
- Collection requiring aspiration or drainage
- Presence regardless of the volume accumulated 5
Common Clinical Settings
Breast surgery represents the most frequent setting for seroma formation, particularly after mastectomy and axillary lymph node dissection, with reported incidence rates ranging from 3% to over 85% 5, 2, 6. The condition is especially prevalent following:
- Mastectomy with axillary dissection (incidence up to 71.1%) 5
- Abdominoplasty with liposuction 7
- Inguinal hernia repair (approximately 10% after TEP repair) 8
- Colorectal surgery 1
Risk Factors
Independent risk factors for seroma development include:
- Obesity or overweight status (1.92-fold increased risk) 5
- Axillary lymphadenectomy (2.06-fold increased risk) 5
- Scrotal hernia in inguinal repair (5.85-fold increased risk) 8
- Bilateral procedures 8
- Recurrent hernia repair 8
- Larger tumor size and presence of hematoma 9
- Current smoking 9
Body mass index and body weight are among the few consistently demonstrated patient factors affecting seroma formation 2.
Clinical Significance
Seroma formation is problematic because it:
- Increases infection risk
- Causes patient discomfort and pain
- May delay adjuvant therapy (chemotherapy or radiation)
- Requires additional outpatient visits for aspiration
- Increases healthcare costs 5, 2
- Can lead to scar complications 5
Management Approach
Recurrent transcutaneous aspiration remains the primary successful management strategy 2. Most seromas require an average of two aspiration procedures until resolution 5. The fluid typically reaccumulates after initial drainage, necessitating serial aspirations until the cavity obliterates.
For persistent sterile collections (seromas, lymphoceles), intracavitary sclerotherapy with agents such as ethanol, doxycycline, or tetradecyl sulfate has shown high success rates in shortening catheterization periods 10.