Do anticoagulation medications increase the risk of haematoma in ultrasound-guided fine needle aspiration of thyroid lesions?

Background: A feared complication of thyroid fine needle aspiration (FNA) is bleeding diathesis and haematoma at the biopsy site. Patients are often advised to discontinue antithrombotic/anticoagulant (AT/AC) medications prior to the procedure. The aim of this study was to examine the risk of bleeding in patients on AT/AC medications undergoing cervical ultrasound (US)-guided FNA. Methods: A retrospective chart review of 803 patients who underwent US-guided FNA of thyroid nodules over 8 years by a single endocrine surgeon was undertaken. Clinical variables, patient demographics and use of AT/AC medications were collected and analysed. The principle outcome measures included the incidence of procedure-related haematoma formation. Multivariable logistic regression was used to investigate the possible independent association between post-FNA haematoma and anticoagulation, adjusting for age, African American race, body mass index, vascularity and lesion size. Results: A total of 1568 lesions were included in 803 patients. The mean age for the patients on AT/AC was 63.0 ± 10.4 years and those not on AT/AC was 50.1 ± 14.2 years (P < 0.001). Of those, 148 patients had 336 lesions (21%) biopsied while taking one or more daily AT/AC agent (81 patients: aspirin; 11 patients: Plavix; 17 patients: aspirin and warfarin; 30 patients: aspirin and Plavix; seven patients: rivaroxaban and aspirin; and two patients: ticagrelor and aspirin). Three patients (0.89%) in the AT/AC group compared to six patients (0.49%) not receiving AT/AC medications developed a haematoma (P = 0.41). All complications were treated conservatively and none required intervention. Conclusions: US-guided FNA of thyroid lesions can be safely performed on patients taking AT/AC including newer agents, without an increase in adverse outcomes or decreased diagnostic rate. Further larger prospective multi-institutional studies are warranted to further investigate this important finding.