​Clinical Procedures - Fine Needle Aspiration

​Clinical Procedures - Fine Needle Aspiration 
Indications
• Diagnosis of a lump; commonly thyroid and lymph node.
Contraindications
• Bleeding diathesis
• Overlying infection
• Adjacent vital structures. Image-guidance should always be used if available.
Risks
• Bleeding
• Local infection
• Damage to surrounding structures depending on site, e.g. blood vessels, nerves.
Procedure Tips
• © Radiological guidance should always be used if available
• Contact the histopathology department in advance to ensure appropriate transport medium is used. It may be possible to arrange immediate analysis, allowing diagnosis and repeat FNA if insufficient cells are obtained.

A method for obtaining a cytological sample of a mass lesion.
• This procedure should only be performed by, or under strict supervision of, an experienced practitioner.
• Fine-needle aspiration (FNA) usually takes place in the Radiology Department and is performed by an experienced Radiologist under ultrasound or CT guidance. The following describes the older, 'blind' technique.


Equipment
• Local anaesthetic (e.g. 1% lidocaine)
• Small-gauge (blue) needle and 10mL syringe
• Sterile pack
• Cleaning solution (e.g. chlorhexidine)
• Medium-gauge (green) needle
• 10mL or 20mL syringe for aspiration
• Sterile gloves.
Procedure
• Introduce yourself, confirm the patient's identity, explain the procedure, and obtain informed consent
• Position the patient according to the biopsy site, allowing easy palpation of the mass
• Expose appropriately
• Wash your hands and put on sterile gloves
• Clean the area with the cleaning solution and apply drapes
• Instil local anesthetic to the skin and subcutaneous tissues withdrawing the plunger prior to each injection to avoid intravenous injection and warning the patient to expect a
'sharp scratch'
• Immobilize the mass with your non-dominant hand
• Using your dominant hand, insert the needle through the skin into the lump, maintaining negative pressure on the plunger as you go
• Once in the lump, the needle may be moved gently back and forth to obtain a greater volume of cells


It may be necessary to insert the needle several times to obtain a sufficient sample
• Do not expect a large amount of material within the syringe! A tiny sample within the needle will usually suffice
• Remove the needle and send the sample for cytology (you will need to gently expel the sample from the needle into a suitable container)
• Apply a sterile dressing to the site.
Alternative Method
• There are two schools of thought in FNA
• Some practitioners use a small (blue) needle without a syringe attached. This is moved in and out very quickly within the mass whilst also applying rotation. Capillary action deposits a cellular sample within the needle which can then be gently expelled using an empty syringe
• This capillary action technique may result in a larger number of intact cells in the resultant sample as the negative pressure created when using a syringe can disrupt cell membranes.
Documentation
• Date and time
• Indication, informed consent obtained
• Type and amount of local anaesthetic used
• Site of puncture
• Aseptic technique used?
• How many passes?
• Volume and colour of sample obtained
• Any immediate complications
• Tests requested on resultant sample
• Signature, printed name, and contact details.