Overview
Definition:
Vacuum-assisted breast biopsy (VABB) is a minimally invasive technique that uses a vacuum device to draw tissue samples through a needle, typically guided by imaging modalities such as ultrasound, mammography (stereotactic), or MRI
It allows for the retrieval of larger tissue cores compared to conventional fine-needle aspiration or simple core needle biopsy, facilitating more accurate histological diagnosis.
Epidemiology:
VABB is widely employed for evaluating suspicious breast lesions detected by screening mammography or other imaging modalities
Its use has increased with advancements in imaging and biopsy technology, becoming a standard of care for many non-palpable or complex breast findings.
Clinical Significance:
VABB provides a less invasive alternative to surgical excisional biopsy for tissue diagnosis of breast abnormalities
It enables definitive histological characterization of lesions, guiding subsequent management decisions, including the need for further surgery or neoadjuvant therapy
Accurate diagnosis through VABB is crucial for optimizing patient outcomes and minimizing unnecessary interventions.
Indications
Imaging Detected Lesions:
Suspicious microcalcifications, masses, or architectural distortions seen on mammography, ultrasound, or MRI that are not palpable or require larger tissue samples for definitive diagnosis.
Palpable Lesions:
Palpable breast masses when a tissue diagnosis is required, especially when fine needle aspiration is inconclusive or core needle biopsy is technically challenging.
Lesion Localization:
Placement of markers (e.g., metallic clips) for localization of non-palpable lesions prior to surgical excision or for guiding radiation therapy.
Treatment Monitoring:
Assessment of response to neoadjuvant chemotherapy in select cases, though typically performed after completion of treatment.
Contraindications
Absolute Contraindications:
Inability of the patient to cooperate or lie still during the procedure
Active breast infection or inflammation at the biopsy site
Known severe bleeding disorder or anticoagulant therapy that cannot be safely managed.
Relative Contraindications:
Anticoagulant or antiplatelet therapy requiring careful management
History of keloid formation
Large breast size making positioning difficult
Extremely small or very superficial lesions where VABB might be technically challenging or less effective.
Procedure Steps
Patient Preparation:
Informed consent obtained
Review of imaging findings and biopsy plan
Patients are advised to avoid aspirin and NSAIDs for a week prior if possible
Local anesthesia is administered at the biopsy site.
Imaging Guidance:
The lesion is precisely localized using the appropriate imaging modality (stereotactic mammography, ultrasound, or MRI)
The biopsy probe is positioned accurately adjacent to the lesion.
Tissue Sampling:
The VABB device is activated, creating a vacuum that draws tissue into the sampling chamber
A rotating cutting needle or a vacuum-driven aperture excises tissue cores
Multiple samples are typically obtained from different angles to ensure complete sampling.
Post Biopsy Management:
Hemostasis is achieved through direct pressure
A small dressing is applied
A post-biopsy imaging check may be performed to confirm marker placement if indicated and to assess for immediate complications like hematoma
Patients are advised on post-procedure care, including monitoring for bleeding or infection.
Advantages
Larger Tissue Yield:
Retrieves larger and more numerous tissue cores than standard core needle biopsy, increasing the diagnostic accuracy and reducing the need for repeat biopsies.
Minimally Invasive:
Offers a less invasive alternative to surgical excisional biopsy, resulting in smaller scars, reduced pain, and quicker recovery.
Versatility:
Can be performed under various imaging guidance modalities (mammography, ultrasound, MRI), making it adaptable to different types of breast lesions.
Marker Placement:
Facilitates precise placement of localization markers within the lesion for subsequent surgical excision or treatment planning.
Complications
Common Complications:
Minor bleeding or hematoma formation at the biopsy site
Pain or discomfort
Bruising
Seroma formation
Mild infection.
Less Common Complications:
Significant bleeding requiring intervention
Nerve injury causing temporary or permanent numbness
Pneumothorax if the biopsy is close to the chest wall (more with stereotactic biopsy)
Incomplete sampling leading to a false-negative result
Embolization of tissue (rare).
Management Of Complications:
Most minor complications resolve with conservative management (ice packs, pain relief, rest)
Significant bleeding may require pressure, aspiration, or rarely, surgical exploration
Persistent pain or infection may necessitate antibiotics or drainage
Incomplete sampling requires repeat biopsy or consideration of surgical excision.
Interpretation And Reporting
Histopathological Analysis:
The tissue cores are processed and examined by a pathologist to determine the nature of the lesion (benign, atypical, or malignant).
Reporting Key Elements:
Reports should include lesion characteristics, adequacy of sample, specific diagnosis (e.g., fibroadenoma, papilloma, DCIS, invasive carcinoma), and any relevant prognostic or predictive markers (e.g., ER, PR, HER2 status for malignant lesions).
Discordance:
Discrepancy between imaging findings and histopathology should be identified and may necessitate further investigation, such as repeat biopsy or surgical excision, to rule out malignancy.
Key Points
Exam Focus:
VABB is indicated for microcalcifications and non-palpable lesions not amenable to standard core biopsy
It provides larger tissue cores, increasing diagnostic yield
Complications are generally minor but include hematoma and infection
Marker placement is a key feature for non-palpable lesions.
Clinical Pearls:
Ensure adequate local anesthesia for patient comfort
Optimize probe positioning for optimal sampling
Always confirm the adequacy of the sample with the pathologist
Be vigilant for post-biopsy bleeding and hematoma
Discuss the findings thoroughly with the patient and discuss next steps based on the biopsy report.
Common Mistakes:
Failing to adequately anesthetize the site
Incorrect probe angulation leading to suboptimal tissue sampling
Over-reliance on VABB without considering surgical excision for clearly suspicious or large lesions
Not adequately assessing for post-biopsy hematoma or bleeding
Misinterpretation of imaging-pathology discordance.