Application of a Novel Vibrating Device for Fine-Needle Aspiration Cytology

Objective: Fine-needle aspiration cytology (FNAC) is a valuable diagnostic technique. However, the procedure involves backand-forth motions of a needle within a mass, which can lead to unexpected complications. We have developed a novel device and sampling techniques that use vibration and rotation instead of backand-forth motions. Methods: The new device consists of a vibrating motor fixed to the stopper of a 5 ml syringe with its piston. A 22-gauge needle attached to the 5 ml syringe is used for FNAC. Samples were obtained from resected specimens using the following four procedures: suction only; suction and vibration for 5 seconds; suction and 180° rotation of the syringe; and suction, vibration for 5 seconds, and 180° rotation of the syringe. Samples were also obtained using the conventional technique. The numbers of well-visualized follicular groups on glass slides were counted to compare the amounts of cellular material obtained using the five different procedures. Next, 415 patients with thyroid nodules underwent ultrasound-guided FNAC to evaluate the rate of inadequacy. Results: Sufficient amounts of material were obtained from resected specimens using suction, vibration and rotation, and using the conventional technique. Inadequate thyroid FNAC material was obtained in 12.3% of cases. Conclusions: The new device and sampling techniques for thyroid FNAC collected sufficient amounts of adequate material and allowed safe and precise control of the device. Our device and sampling techniques are expected to be widely used not only for thyroid FNAC sampling but also for sampling from other anatomical sites.