No difference in outcome between therapeutic and preventive anticoagulation in patients with superficial vein thrombosis involving the saphenous-femoral junction.

Following the demonstration that thrombosis involving the superficial veins of the lower extremities (SVT) is a less benign disease than previously thought,1 several controlled studies have consistently shown that fondaparinux in preventive doses, low-molecular-weight heparins (LMWHs) in intermediate doses, and rivaroxaban in preventive doses are effective and safe strategies for preventing extension or recurrence of the disease, as well as progression to the deep vein system and migration to the pulmonary circulation.2-6 In all these clinical trials, patients with the thrombus head within 3 cm from the saphenous–femoral junction were not eligible for recruitment, as they were perceived as being at a higher risk of venous thromboembolic complications in the absence of an active drug, nor were they in studies addressing the treatment of deep vein thrombosis (DVT) because of the lack of involvement of the deep vein system. Accordingly, which is the most proper therapeutic conduct in these patients is unknown. International guidelines are elusive in this regard.7,8 Although most physicians end up managing these patients with therapeutic doses of anticoagulants because of the feared risk of progression to the deep vein system, as far as we know there is no evidence of treatment failure coming from the long-term follow-up of patients managed with lower doses. Here we report the findings from an international registry. The Computerized Registry of Patients with Venous Thromboembolism (RIETE) (ClinicalTrials.gov Identifier: NCT02832245) is a large prospective registry that has been enrolling patients with objectively confirmed VTE since 2001.9 The main objective of RIETE is to provide information to help physicians to improve their knowledge on the natural history of thromboembolic disease, including epidemiologic, diagnostic, prophylactic, and therapeutic information. All enrollees provide written or verbal informed consent according to the local ethics protocols of enrolling centers. The institutional review board at each enrolling center approves participation in RIETE for the site investigators and allows the entry of de-identified patient information into the RIETE database. Out of 1320 patients with isolated SVT (i.e., without simultaneous involvement of the deep venous system, as assessed by systematic bilateral ultrasonography) who were enrolled in the RIETE registry between March 2015 and June 2021, 374 (28.3%) had a thrombosis involving the most proximal tract of the greater saphenous with the thrombus head being within 3 cm from the saphenous–femoral junction. Of these patients, 227 (60.7%) were managed with full-dose LMWH or therapeutic doses of fondaparinux overlapped with and/or followed by vitamin K antagonists or direct oral anticoagulants. The remaining 147 patients (39.3%) were managed with preventive doses of fondaparinux or intermediate-dose LMWH. Table 1 illustrates the main demographic and clinical characteristics of the recruited patients, as well as the main risk factors of thrombosis, which were fully comparable between the two study No difference in outcome between therapeutic and preventive anticoagulation in patients with superficial vein thrombosis involving the saphenous–femoral junction