In image-guided percutaneous biopsy, co-axial technique is preferred over direct (single-pass) technique because it:

• A Eliminates the need for local anaesthesia
• B Allows multiple specimens from a single skin puncture through one introducer needle, reducing haemorrhage and tumour seeding risk ✓
• C Provides larger specimen cores with a single pass
• D Is faster and requires less imaging guidance

Explanation

The co-axial biopsy technique places a larger-bore introducer (co-axial) needle through the skin and deep tissues to the target, and then multiple smaller biopsy needles are passed through the introducer channel to obtain repeated specimens. Advantages: multiple cores from a single puncture (reducing track haemorrhage, pneumothorax risk with each pass), the same access can deploy other devices (eg. ablation probes), and the introducer's stylet plugs the track on removal to reduce tumour seeding along the biopsy tract. The introducer needle also allows injection of haemostatic material on withdrawal. Direct single-pass technique requires repeated skin and tissue punctures for each core, increasing complication risk.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.