Recurrent splanchnic and extrasplanchnic thrombotic events in patients with non-cirrhotic portal vein thrombosis associated with local factors

One third of recent non-cirrhotic portal vein thrombosis are associated with local factors. The risk of rethrombosis after anticoagulation withdrawal is unknown. We aimed to determine factors associated with splanchnic or extrasplanchnic new thrombotic events in that setting. Methods Retrospective study including recent non-cirrhotic portal vein thrombosis associated with local factors. High and low prothrombotic risk factors, prespecified according to Riport study criteria, were assessed. Quantitative and qualitative variables are presented as median (inter-quartile range), and absolute and relative frequencies respectively. Univariate and multivariate Cox models assessed the influence of different variables on the occurrence of a new thrombotic event. Results At baseline, 83/154 (53.9%) had at least one prothrombotic factor including 50 (32.5%) high-risk and 33 (21.4%) low-risk prothrombotic factors. Oestrogen containing contraception was discontinued in all patients. During follow up, 63/140 (45%) patients had at least one prothrombotic factor, including 47 (33.6%) with a high risk, and 16 (11.4%) a low risk prothrombotic factor. Seventeen new thrombotic events occurred after a median follow-up of 52 (IQR 14-62) (min–max 3.0-69.0) months. New thrombosis were associated with high risk factors (HR 3.817, 95% CI [1.303-11.180], p= 0.015), but inversely related to recanalization (HR 0.222, 95% CI [0.078-0.635], p=0.005) and anticoagulation (HR 0.976, 95% CI [0.956-0.995], p=0.016). When a high-risk factor was present a new thrombotic event occurred in 7.4%, 14.6%, 14.6% and 28.8% of patients at 1, 3, 5 and 7 years under anticoagulants compared to 21.2%, 21.2%, 58% and 58% without anticoagulants. Conclusions In recent non-cirrhotic portal vein thrombosis associated with local factors, high risk factors for thrombosis are associated with new thrombotic events. Permanent anticoagulation appears beneficial in this high-risk situation. Impact and implications In noncirrhotic portal vein thrombosis (NCPVT) associated with local factors, systematic screening for prothrombotic factors is recommended, but prevalence of the latter is not clearly established, and the risk of recurrent intra or extra splanchnic thromboembolism is poorly described. Thus, interest in permanent anticoagulation therapy is still pending.NCPVT associated with local factors, is a matter of concern for hepatologists, gastroenterologists and digestive surgeons. Due to a lack of knowledge, practices are heterogeneous.Our findings highlight that systematic screening for prothrombotic factors in NCPVT is strongly needed even when associated with local factors, as it may justify long-term anticoagulation therapy for the prevention of new intra or extra-splanchnic thrombotic events in at least one-third of cases.The interest in long-term anticoagulation should be investigated prospectively in the absence of prothrombotic factors with high risk of thrombosis. Clinical trial number NCT0536064