Ultrasound-guided fine-needle aspiration biopsy of thyroid nodules in patients on oral anticoagulants.

recommended not stopping any antithrombotic drugs before USGFNAB. In their article Lyle and Dean extend this advice to the so called NOACs (non-vitamin K oral anticoagulants), direct inhibitors of coagulation acting on FII or FXa that are on the market since 2010. These authors recommend not interrupting AVK or low-molecular weight heparins (LMWHs), as well as NOACs prior to or following an USGFNAB. On the other hand, in a review published in the J Ultrasound Med in 2011, authors clearly recommended to take the patient off the anticoagulant for an appropriate amount of time before and after the biopsy [4]. They recommend stopping the warfarin for 5 days, performing biopsy if the international normalized ratio is less than 1.5 to 1.7. If the patient is taking LMWHs such as enoxaparin sodium, the medication should be stopped for 12 h. Alternatively, when physicians determine it’s more safe for the patient to remain anticoagulated, they should give the advice to stop the patient’s warfarin 2 days before the biopsy and at that time (2 days before it) begin enoxaparin subcutaneously every 12 h (bridging procedure). Warfarin may be restarted the day after the fine-needle aspiration with the patient continuing to receive enoxaparin until the INR becomes therapeutic (2–3 range). In this last case, authors suggest to clearly explain to the patient that with this regimen that there is a mildly increased risk of bleeding. As discussed in the Lyle article, data in regards to patients on AVK undergoing FNA are scarce and retrospective in nature. Notwithstanding, they show a low incidence of hemorrhage, experts in the field recommend to withdraw AVK before this procedure. We believe that the bridging procedure is safer than AVK suspension for 5 days because a too large period without anticoagulation is unacceptable for many patients at a high risk for thromboembolism. On the other hand, patients on AVK may have an unpredictable risk of serious bleeding. Dear Editor,