Thursday, October 27, 2011

How To Perform An Ultrasound-Guided Breast Biopsy

A quick Google search for 'how to perform an ultrasound-guided breast biopsy' produces many results. However, most are oriented at patients, not practitioners. You could try reading the ACR guidelines for ultrasound breast biopsy, but good luck actually learning how to do the procedure from that. This post aims to be a guide aimed at residents and other trainees on how to perform a breast biopsy using ultrasound and standard equipment. Please note, this post assumes that the biopsy is indicated based on suspicious mammogram findings (typically, BIRADS 4A or higher).

Preparation & Consent

  • Review imaging results, including any relevant mammograms and ultrasounds.
  • Make sure you have all necessary equipment available.
  • To consent, first confirm that you have the right patient and right procedure
  • After taking the patient to a private area, describe the procedure. 
  • Be sure to explain that clip will be left and patient will have a mammogram afterwards to confirm location of clip/biopsy
  • Risks
    • Pain (will use local anesthesia)
    • Bleeding / Hematoma formation (low; anesthesia may include epinephrine)
    • Infection (low; ~1/1000)
    • Damage to adjacent structures (chest wall, pneumothorax, implant rupture, etc)
    • Non-diagnostic biopsy / need for return
  • Have patient sign the consent, retain the signed copy, give a copy to the patient.
  • Explain post-procedure instructions
    • Do not wash the area for two days
    • Maintain wrap for two days
    • No heavy lifting for two days
    • Only use Tylenol or ice packs for pain control (no aspirin or Ibuprofen)
    • If pain persists, or breast becomes red and swollen, contact provider.

  • The patient should be positioned supine on the bed with the breast to biopsy exposed and marked by the ultrasound technologist. A support may be placed underneath the breast of interest to better expose the target area.
  • Perform a timeout to ensure the correct patient and correct procedure.
  • Open kit
    • Tape needle tray down
    • Cut keyhole opening in drape if necessary.
    • Put loading needle on syringe
  • Raise bed to the level that your elbow is bent about 90 degrees. You should be comfortable.
  • Put on sterile gloves and clean the area with betadine. This is also known as "prep and drape in the usual sterile fashion."
  • Take probe cover from the ultrasound tech and cover probe; secure with rubber band.
  • Load Bicarb + Lido without epi (9:1); Load Bicarb + Lido with epi (9:1). Use the lidocaine without epinephrine for the skin wheal to prevent skin necrosis.
  • Unpack the biopsy device and clip. 
    • The device you choose to use depends on the lesion characteristics.
    • For superficial lesions, try a standard biopsy needle (may be referred to as Temno/Bard/scissors/etc).
    • For deeper lesions, use a vacuum-assisted device (ex. Mammotome). The advantage of having vacuum on is that the tissue is pulled down into the trough, and the larger gauge creates a larger tissue sample.
  • Scan area to locate lesion; turn flow on to ensure no large vessels are nearby.
  • Create surface wheal with lido without epi; insert needle up to 2 cm away from the probe a for deeper mass
  • Use spinal needle (or other anesthesia needle) to create tract to lesion; insert anesthesia as needed.
  • Aim to get tip of needle beneath lesion and put copious lidocaine to raise the lesion. This is especially important for deep lesions near the muscle wall.
  • Retract needle and then use scalpel to widen dermatotomy if necessary.
  • Insert sampling device and aim for center of lesion
    • For Temno / Bard, insert with device loaded but trough closed. Once through lesion, open trough, let the technologist record a picture, then fire
    • For vacuum-assisted device, make sure the device in correct clock position, then ask tech to picture and take sample for you
  • After firing, retract the device and hand sample to tech
  • Repeat 3-6 times for the biopsy needle; 4-8 times for the vacuum-assisted device.
  • After last sample, insert a clip to mark the location and have the technologist record the location on the ultrasound machine.
  • Withdraw clip insertion device, apply pressure for hemostasis.
  • Remove drapes, clean with wet gauze then dry, then apply bandage.
  • Ensure sample is properly stored and documented. Send the patient for a post-procedure mammogram.
Ideally the lesion and the tip should always be in view, which means the ultrasound probe should be scanning a plane that contains both.

That's it! Not too involved for a procedure, but it is important to get practice coordinating the ultrasound probe with the needle as it advances. For patient information on this procedure from ACR, click here.

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