Biopsy Gun in Pediatric Care: Types, How It Works, and Safety Guide
Introduction
A biopsy gun is a spring-loaded medical device used to collect small tissue samples from inside the body. These samples are then examined under a microscope in a laboratory to identify abnormal or diseased tissue â including cancer, infections, or other conditions.
In pediatric medicine, biopsy guns are used when a tissue sample is needed from organs such as the liver, kidney, or soft tissue masses in children. The device is designed to collect the sample quickly and with minimal discomfort compared to older open surgical methods.
Key Point
A biopsy gun is not a treatment device. It is a diagnostic tool â it helps identify what a tissue or growth is made of so the right treatment can be planned.
Purpose and Where It Is Used
The main purpose of a biopsy gun is to take a core needle biopsy â a small, cylindrical piece of tissue â from a specific area of the body without the need for open surgery.
Common reasons a biopsy gun is used in children:
- To investigate an unexplained lump or mass in soft tissue
- To diagnose liver disease (such as hepatitis, storage disorders, or tumors)
- To evaluate kidney disease or a renal mass
- To assess bone marrow in some bone lesions
- To confirm or rule out childhood cancers (such as lymphoma or nephroblastoma)
- To monitor organ function after a transplant (e.g., liver or kidney transplant biopsy)
Where the procedure is performed:
- Radiology departments (using ultrasound or CT guidance)
- Pediatric surgical suites
- Interventional radiology units
- Outpatient procedure rooms in tertiary care hospitals
Imaging Guidance
In pediatric practice, biopsy guns are almost always used under ultrasound or CT guidance to ensure the needle reaches exactly the right spot and avoids major blood vessels or nerves.
Types of Biopsy Guns
Biopsy guns are available in different designs depending on the organ being sampled, the needle size, and whether they are reusable or single-use.
| Type | Description | Common Use |
|---|---|---|
| Automatic Biopsy Gun | Spring-loaded, fires with a single button press; two-phase action (inner stylet then outer cutting cannula) | Liver, kidney, soft tissue |
| Semi-Automatic Biopsy Gun | Inner stylet advances automatically; outer cutting sheath advanced manually | When more control is needed |
| Manual Core Needle | Completely hand-operated; no spring mechanism | Rarely used now; some bone biopsies |
| Side-Cut Biopsy Gun | Cuts tissue from the side of the needle tip rather than the end | Liver biopsies, some renal biopsies |
| End-Cut Biopsy Gun | Cuts from the tip of the needle | Hard tissue or deep lesions |
| Disposable (Single-Use) | Pre-loaded, used once, and discarded | Standard in most modern hospitals |
| Reusable (Multi-Use) | Sterilisable gun body with disposable needles | Some resource-limited settings |
Needle sizes (gauge):
Biopsy needles are measured in gauge (G). In pediatric practice, commonly used sizes are 16G, 18G, and 20G. A higher gauge number means a thinner needle. The choice depends on the organ, depth, and the amount of tissue needed.
How a Biopsy Gun Is Used: Step-by-Step
Note
This procedure is performed only by trained medical professionals in a clinical setting. Sedation or general anaesthesia is commonly used in children to ensure comfort and safety.
Before the Procedure
- Clinical review: The medical team reviews imaging (ultrasound, CT, or MRI) to locate the area to be biopsied and plan the approach.
- Blood tests: Clotting profile (PT, INR, platelet count) is checked to reduce bleeding risk. Any blood thinners or anticoagulants are reviewed.
- Fasting: The child is kept fasting for an appropriate period before the procedure as required for sedation or anaesthesia.
- Consent: Written informed consent is obtained from the parent or legal guardian, and assent is taken from older children where appropriate.
- Positioning: The child is positioned (supine, prone, or lateral) depending on the organ being targeted.
- Sedation or anaesthesia: Administered by a trained anaesthetist. Local anaesthesia is also applied to the skin entry point.
During the Procedure
- Skin cleaning: The skin over the biopsy site is cleaned with an antiseptic solution and sterile drapes are placed.
- Imaging guidance setup: An ultrasound probe (covered with a sterile sheath) or CT guidance is used to locate the target in real time.
- Skin incision: A small nick (1-2 mm) is made in the skin using a sterile scalpel blade to allow the biopsy needle to pass through smoothly.
- Needle insertion: The biopsy gun with the loaded needle is introduced through the incision and advanced under imaging guidance towards the target tissue.
- Firing the gun: Once the needle tip is confirmed to be at the correct position, the gun is fired. The spring-loaded mechanism rapidly advances the inner stylet and then the cutting cannula, taking a core of tissue in a fraction of a second.
- Sample retrieval: The needle is withdrawn. The tissue core (approximately 15-20 mm long) is removed from the notch of the needle using a sterile needle or forceps and placed in a labeled specimen container with appropriate preservative (usually formalin, unless fresh tissue is required).
- Repeat passes: Usually 2-3 passes are made to collect enough tissue. Each pass uses a fresh needle.
After the Procedure
- Pressure and dressing: Firm pressure is applied to the puncture site for several minutes. A sterile dressing is applied.
- Monitoring: Vital signs (heart rate, blood pressure, oxygen saturation) are monitored for at least 4-6 hours. For liver or kidney biopsies, a longer observation period may be required.
- Post-procedure imaging: An ultrasound is often performed immediately after to check for any bleeding (haematoma).
- Activity restriction: Strenuous activity is avoided for 24-48 hours as advised by the treating team.
- Specimen dispatch: The tissue sample is sent to the pathology laboratory with all relevant clinical information.
- Results: Histopathology results are usually available within 3-7 working days depending on the laboratory.
Precautions and Possible Risks
Contraindications (when biopsy gun should not be used):
- Severely abnormal clotting (uncorrected coagulopathy)
- Very low platelet count that cannot be corrected
- No safe needle path visible on imaging
- Vascular tumours (such as haemangiomas) â risk of severe bleeding
- Active infection at the biopsy site
- Echinococcal (hydatid) cysts â risk of anaphylaxis if punctured
Known risks and complications:
| Complication | Frequency | Notes |
|---|---|---|
| Minor bleeding / bruising | Common | Usually self-limiting |
| Significant haematoma (blood collection) | Uncommon (1-3%) | May require observation or intervention |
| Pain at biopsy site | Common | Usually mild and short-lived |
| Infection | Rare (<1%) | Sterile technique minimises this |
| Pneumothorax (collapsed lung) | Rare | Risk with lung or high posterior biopsies |
| Organ injury | Very rare | Imaging guidance greatly reduces this |
| Tumour seeding along needle tract | Very rare | Recognised theoretical risk; relevant in some tumour types |
| Inadequate sample (non-diagnostic) | Occurs in some cases | May require repeat biopsy |
Warning Signs After Biopsy
Seek immediate medical attention if the following occur after the procedure: severe or increasing pain, swelling or firmness at the biopsy site, fever above 38 degrees Celsius, blood in urine after a kidney biopsy, difficulty breathing, or increasing paleness and rapid heart rate. These may indicate a serious complication.
Special Considerations in Pediatric Biopsy
- Sedation or general anaesthesia is almost always required in young children to prevent movement during the procedure, which could cause injury.
- Smaller needle gauges (18G or 20G) are preferred in infants and small children to reduce tissue trauma.
- Organ size: Children's organs are smaller, making imaging guidance even more critical to avoid adjacent structures.
- Sample size: Laboratories performing pediatric histopathology are experienced in evaluating smaller cores of tissue, which is often sufficient for diagnosis in children.
- Post-procedure observation is often longer in children, particularly after liver or kidney biopsy.
- Neonates and very young infants require specialised planning and may need procedure in an operating theatre setting.
How to Handle and Keep the Device Safe
For healthcare facilities:
- Store biopsy guns and needles in a dry, clean environment, away from moisture and direct sunlight.
- Check the expiry date on all disposable biopsy guns and needles before use. Never use an expired device.
- Inspect packaging for any damage, tears, or broken seals before opening. A compromised package means the device is no longer sterile.
- Single-use devices must never be reused, reprocessed, or resterilised. This is a safety regulation followed internationally.
- Reusable gun handles must be cleaned and sterilised according to the manufacturer's validated instructions after every use.
- After use, needles must be disposed of in a sharps container immediately. Never recap used needles by hand.
- All used biopsy devices are classified as clinical waste and must be disposed of following local biomedical waste regulations.
- Maintain a log of device batch numbers and expiry dates for traceability and recall management.
Storage Tip
Most biopsy guns should be stored at room temperature (approximately 15-30 degrees Celsius) in a dry place. Always refer to the specific manufacturer's instructions for storage conditions.
Frequently Asked Questions (FAQ)
Is a biopsy gun painful for a child?
Children are given sedation or general anaesthesia before the procedure, so they do not feel pain during it. Some soreness at the biopsy site is normal for 24-48 hours after the procedure and is managed with standard pain relief.
How long does a biopsy gun procedure take?
The actual needle biopsy takes only a few seconds per pass. The full procedure including preparation, sedation, imaging guidance, and post-procedure check typically takes 30 minutes to 1 hour. Monitoring after the procedure adds several more hours.
How many needle passes are needed?
Usually 2 to 3 passes are made to collect enough tissue for a reliable diagnosis. The exact number depends on the organ, the quality of the cores obtained, and the pathologist's requirements.
Is a biopsy gun the same as a fine needle aspiration (FNA)?
No. Fine needle aspiration uses a thin needle to collect loose cells (cytology). A biopsy gun uses a larger cutting needle to collect a solid core of tissue (histology). Core biopsy with a biopsy gun provides more information about tissue architecture and is generally preferred for diagnosing most solid organ conditions in children.
When will the biopsy results be available?
Standard histopathology results are available in 3 to 7 working days. Some tests such as cultures, immunohistochemistry, or electron microscopy may take longer.
Can a biopsy gun spread cancer cells?
Needle tract seeding is a known but very rare risk. In pediatric oncology, the choice of biopsy approach â including which direction to take the biopsy â is carefully planned to minimise this risk, especially when surgery to remove the tumour may follow.
Can biopsy guns be reused?
Disposable (single-use) biopsy guns must never be reused. Reusable gun handles may be sterilised and used again with fresh, disposable needles, but only according to the manufacturer's validated instructions. Misuse of single-use devices is dangerous and not permitted.
What is the difference between a 16G and an 18G biopsy needle?
16G is a wider needle and collects a larger tissue core. 18G is thinner and is often preferred in smaller children or when there is a higher bleeding risk. The choice is made based on the organ, the child's size, and clinical needs.
Is general anaesthesia always necessary for a biopsy in children?
Not always, but in most young children, general anaesthesia or deep sedation is used to keep the child still and comfortable and to prevent accidental injury from movement. Older cooperative adolescents may sometimes be managed with local anaesthesia and mild sedation, depending on the site and clinical assessment.
Suggested References
The following are authoritative sources for further reading:
- Books: Nelson Textbook of Pediatrics (Kliegman et al.) | Practical Pediatric Gastrointestinal Endoscopy (Wyllie et al.) | Pediatric Radiology (Siegel)
- Websites: UpToDate (uptodate.com) | Radiopaedia (radiopaedia.org) | American College of Radiology (acr.org) | World Health Organization (who.int) | National Institutes of Health - PubMed (pubmed.ncbi.nlm.nih.gov)
Medical Disclaimer: The information on this page is intended for general educational purposes only. It does not constitute medical advice and is not a substitute for professional medical consultation, diagnosis, or treatment. All medical procedures, including biopsy, must be performed only by qualified and trained healthcare professionals in an appropriate clinical setting. Individual cases vary â always seek guidance from a licensed medical professional for any health concern or before making any medical decision. PediaDevices does not endorse any specific product, brand, or manufacturer.
Medically reviewed by a Pediatrician | PediaDevices
Labels: Diagnostic-Devices