Isolated Distal Deep Vein Thrombus Detected before Orthopedic Surgery: Is Preoperative Anticoagulation Preferable?

: We evaluate the efficacy of anticoagulant administration for isolated distal deep vein thrombus (IDDVT), detected before orthopedic surgery. : The study included 32 patients diagnosed with IDDVT before orthopedic surgery in our hospital between October 2011 and October 2017. They were divided into two groups: the 'pre- and post-operative therapy group,' who were administered anticoagulants both pre- and post-operatively, and the 'post-operative therapy group,' who were administered anticoagulants only after surgery due to risk of bleeding judged by an orthopedic surgeon. We compared the primary efficacy (change in IDDVT size) between the two groups. : The proportion of patients with increased post-operative IDDVT sizes was significantly larger in the post-operatively treated group than in the pre- and post-operatively treated group (44.4% vs. 8.7%, p=0.026). No case demonstrated an IDDVT extension proximal to the popliteal vein or presented with symptomatic pulmonary thromboembolism in this study. : Based on our findings, we recommend that, in patients with IDDVT detected prior to orthopedic surgery and administered anticoagulant therapy only after the procedure because of a bleeding risk, a lower limb ultrasonography to re-evaluate the existing deep vein thrombus should be conducted before beginning rehabilitation.