Ultrasound-Guided Fine-Needle Aspiration Biopsy of Thyroid Nodules: is it Necessary to Use Local Anesthesia for the Application of One Needle Puncture?

Objective: This study was designed to evaluate the difference in the degree of patient pain for an ultrasound-guided fine-needle aspiration biopsy (US-FNAB) of a thyroid nodule with one needle puncture with and without local anesthesia. Materials and Methods: A total of 50 patients participated in the study. We examined prospective patients who would undergo US-FNABs of two thyroid nodules (larger than 10 mm maximum diameter), which were located in separate thyroid lobes. For one of these thyroid nodules, US-FNAB was performed following the administration of local anesthesia; for the other nodule, no anesthesia was administered. The application of anesthesia was alternatively administered between patients (either prior to the first US-FNAB procedure or prior to the second procedure). For all patients, the degree of pain during and after each US-guided FNAB was evaluated according to a 4-category verbal rating scale (VRS), an 11-point numeric rating scale (NRS) and a 100-mm visual analogue scale (VAS). Results: The mean maximum diameters of thyroid nodules examined by US-FNAB with the use of local anesthesia and with no local anesthesia were 13.6 mm and 13.0 mm, respectively. There was no significant difference in nodule size (p > 0.05) between two groups. For the VRS, there were 27 patients with a higher pain score when local anesthesia was used and four patients with a higher pain score when no local anesthesia was administered. Nineteen patients had equivalent pain score for both treatments. This finding was statistically significant (p < 0.001). For the NRS, there were 33 patients with a higher pain score when local anesthesia was used and 10 patients with a higher pain score when no local anesthesia was administered. Seven patients had an equivalent pain score for each treatment. This finding was statistically significant (p < 0.001). For the VAS, there were 35 patients with a higher pain score when local anesthesia was used and 11 patients with a higher pain score where no local anesthesia was administered. Four patients had an equivalent pain score for both treatments. This finding was also statistically significant (p = 0.001). Conclusion: In our study, patient pain scales were significantly lower when no local anesthesia was used prior to US-FNABs of thyroid nodules as compared to when local anesthesia was administered. Therefore, we believe that when one needle puncture is used, US-FNAB should be performed without administering local anesthesia.