PB1322 - A ten-year Australian experience of splanchnic vein thrombosis

Background: There is lack of consensus in the management of splanchnic vein thrombosis (SVT), in part due to the rarity and heterogeneity of these cases.

Aims: To evaluate the risk factors, diagnosis, management and complications of SVT.

Methods: A ten-year retrospective evaluation of consecutive SVT presentations at Northern Health, Victoria, Australia, from January 2011 to December 2020 was conducted. The mean follow-up was 19 months. The results were compared to our DVT/PE database of the same period.

Results: 98 patients (64 males; mean age 64 years) presented with 99 episodes of SVT. 94% were symptomatic with the main portal vein most commonly involved (n=61). SVT patients were more likely male and have active malignancy compared to those with DVT/PE (Table 1). 41% had concurrent intra-abdominal infection, 14% had recent intra-abdominal surgery and 33% had active malignancy. Thirty-four patients (35 cases) had underlying cirrhosis. Thirty-two patients were screened for JAK2 V617F mutation of which three patients (including 1 cirrhotic patient) were subsequently diagnosed with myeloproliferative neoplasm. Patients with cirrhosis were more likely to not be anticoagulated compared to non-cirrhotic patients and those with DVT/PE. Eighteen patients (including 5 cirrhotic patients) with SVT received direct oral anticoagulant without known bleeding or thrombotic complications. Cirrhotic patients reported more recurrent thrombotic events (3 SVT and 2 DVT/PE) or clot progression (n=1) compared to non-cirrhotic patients with two recurrent thrombotic events (1 SVT and 1 DVT) and one clot progression (15.6 vs 3.3 events/100-person-years; HR 7.0 (95%CI 1.3-36.6), p=0.022). The rate of clinically significant bleeding on anticoagulation was comparable across groups.

Conclusion(s): Splanchnic vein thrombosis is more likely to be provoked compared to DVT/PE, with malignancy and abdominal infections as common causes. Cirrhotic patients have a higher rate of thrombotic complications compared to non-cirrhotic patients (HR 7.0, 95% CI 1.3-36.6) suggesting a careful assessment of individualised anticoagulation decision is needed.