Ultrasound-guided needle biopsy in the abdomenMedical editor Arne Heilo MD
Oslo University Hospital
Kathleen Schmeler MD
MD Anderson Cancer Center
CT and other radiological examinations are often used for assessment of possible spreading of different cancer types. For these examinations, it is possible to find enlarged lymph nodes or unspecific lesions where it is necessary to confirm or exclude metastases. If the lesion is visible on ultrasound, ultrasound-guided biopsy is the optimal method for clarification. The exception is for suspicion of sarcoma which should be adequately reported with pictures before sample collection. The indication assessment is done by a sarcoma specialist.
Ultrasound-guided biopsy is a quick method for diagnosing possible pathology of suspect lesions/changes deep in the abdomen. We always use fine-needle aspiration initially. The cell sample is stained immediately and assessed by a cytologist. In many cases, the diagnosis for metastasis or reactive lymph node is certain after rapid staining and microscopy. When relevant, a pistol biopsy is performed as well. In these cases, it is necessary to wait 4-6 days to initiate treatment while awaiting the result.
- Lesions of unknown type in the abdomen evident by radiological examinations.
- Confirm or exclude metastases of suspect lesions in the abdomen evident by radiological examinations.
- Ultrasound apparatus with (transducer) for the procedure.
- Local anesthetic (5 ml Xylocain 10 mg/ml). (Not always for cytological biopsies - always for histological biopsies.)
- Syringe (5 ml) and needle for anesthesia. (22 G B&D spinal needle)
- Needle for cytology material. (22 G B and D spinal needle)
- 4 specimen slides for the material
For a histological biopsy with biopsy pistol, the following is used additionally:
- separate 18 G or 16 G needle + pistol, possibly disposable
- glass slides for storage of histological material (formalin, Ringer solution, McCoy, dry glass slides for freezing etc. – depending on tentative diagnosis).
For sterile bandaging (used for local anesthesia)
- Sterile cover
- Sterile disposable tweezers
- Sterile compresses 5 x 5 cm
- Chlorhexidine colored 1 mg/ml
- Sterile gloves
- Sterile condom for UL-head
- Sterile gel
- Mepore bandage 6 x 7 cm
- For ultrasound-guided puncture in the abdomen, the patient should fast the last 4 hours before the exam for best possible access.
- Depending on the localization and localization of the lesion, normal blood tests should be done beforehand for bleeding parameters (hemoglobin, thrombocytes, possibly INR).
- The patient is informed about what will happen.
- The patient should lie comfortably on the examination table.
- Inform the patient during the procedure.
Ultrasound-guided biopsy is taken with or without local anesthesia depending on depth, localization, and patient cooperability.
- Localize the lesion with the ultrasound probe.
- Determine the best puncture point and direction.
- Wash the point of puncture with colored chlorhexidine 1 mg/ml.
- Allow the skin to dry.
- Inject the local anethesia with the help of ultrasound in the entire puncture canal, especially the skin, muscle fascia, peritoneum, and organ surfaces. It is important the patient does not experience any pain when the biopsies are taken. If the puncture is painful, it is easy to lose control of the needle, and small lesions are difficult to reach.
- Puncture the spinal needle quickly through the skin.
- Insert the the needle with the help of ultrasound through the peritoneum and into the lesion.
- Retrieve the mandrin.
- Move the needle back and forth 2-3 times per second. Due to capillary action, the cells will be collected in the needle.
- When the material is evident in the upper part of the needle, it is retrieved.
- Deposit the material onto a specimen slide.
Spread for cytology
- Spread the material out with a specimen slide.
- Dry the material under a fan or similar.
- Staining: fixation fluid with methanol + haemacolour + rinsing in water:
- 5 dips in fixator: allow the solution to drip off the paper.
- 3 dips in color solution 1.
- 6 dips in color solution 2. Allow the solution to drip off the paper.
- Rinse in 2 baths of clean water.
- Examine the specimen under a microscope with 10x or 20x objective.
Microscopic assessment of cell material is done by a cytologist to determine if supplementary tests are necessary.
Histological biopsy (pistol biopsy)
- Place local anesthesia in the entire puncture canal down to the lesion. This is done with the help of ultrasound.
- Make a small incision in the skin.
- Insert the biopsy needle up to the lesion, preferably a little ways in, depending on the size of the lesion and type of tissue in front and behind the lesion.
- Pull the trigger to take the sample.
- Retrieve the needle and open it.
- Place the piece of tissue in a holder with transfer medium, for example formalin.
- After uncomplicated biopsies, outpatients must remain at the hospital for 1 hour before going home.
- Depending on the localization of the lesion and nature, bleeding may occur after the biopsy procedure.
- For intense pain or bleeding, the patient must be observed at the post or intensive unit, depending on severity, while necessary measures are taken.