Ultrasound-guided FNA of the thyroid

ApproachUltrasound guided fine needle aspiration cytology refers to a minimally invasive procedure where where tissue samples are collected from a suspicious lesion or area  using a needle under the guidance of ultrasound.It is usually done on a out patient basis and limitationsgenerally complications are very minimal.

Procedure:

• Preprocedure -  Procedure is discussed with the patient and informed consent is obtained.Patients coagulation profile should be obtained (not routinely on case by case basis ) and any prior relevant medical history/ current medications is to ultrasound guided fnac proceduresbe noted.

• Positioning - Patient is placed in a supine position with mild extension of neck.The lesion is localized, internal vascularity is assesed and adjacent structures at risk are noted.The best point of approach is noted ,i personally prefer to put a marking over this point.

• Procedure -  Overlying skin is cleaned with povidoneiodine solution and draped.About 1-2 ml 1% lidocaine is injected into superficial subcutaneous tissue over the level of interest.22-27 gauge needle is used with 20 ml syringe.Patient should be instructed not to swallow or speak during the insertion of needle.Transducer( linear with probe cover) is placed over the lesion and the needle is introduced parallel or perpendicular to the transducer.The needle tip is carefully monitored and when the region of interest  is reached to and fro motion with active suction is performed.In non aspiration technique( for hyper-vascular nodules) no suction is used. Vigorous to and fro motion with needle being rotated on its axis is done here with no suction.The material is then placed on glass slide smeared and fixed.

• Complications - possible complications are mild localized pain radiaiting to the ear,localized hematoma