Avoiding Risks of Thrombosis and Bleeding in Surgery (ARTS)



Each year, millions of patients who undergo surgery incur the risk of deep vein thrombosis and pulmonary embolism – together referred to as venous thromboembolism (VTE) – and major bleeding. Because pharmacological prophylaxis decreases the risk of VTE, but increases the risk of bleeding, and because knowledge of the magnitude of these risks remains uncertain, both clinical practice and guideline recommendations vary widely.

Currently the most used agents for thromboprophylaxis are injectable low molecular weight heparins. However, direct oral anticoagulants (DOACs) that obviate the need for injections, are less burdensome for patients and thus result in higher adherence and better real-life effectiveness. Although DOACs are widely studied and used in internal medicine (including treatment of VTE and atrial fibrillation) and orthopedic surgery, they remain unstudied in randomized trials in abdominal and pelvic surgery.

To determine DOACs effect on symptomatic VTE and major bleeding,  in conjunction with the Clinical Urology and Epidemiology Working Group (CLUE) the based in University of Helsinki, we will conduct the UK arm of a multicenter randomised trial, comparing a DOAC, apixaban, to no anticoagulation in 5,300 patients undergoing general/abdominal, gynecologic or urologic surgery in whom the anticipated risk of VTE and bleeding are similar. In a subset of 1,000 patients, we will perform advanced further testing/analyses and aim to discover new ways to stratify patients for both VTE and bleeding risks.

Our trial will be the first to compare anticoagulation with DOACs vs no anticoagulant in patients undergoing abdominal or pelvic surgery.

Possible outcomes include:

1) A clear net benefit in favor of DOACs

2) A clear net benefit to not using prophylaxis

3) a sufficiently close tradeoff that predictive factors and patients’ preferences regarding bleeding versus VTE determines the decision, will lead to major change in clinical practice worldwide


Steering group members:

Prof Kari Tikkinen Global PI (Professor of Urology at the University of Helsinki),

Prof Beverley Hunt OBE, UK Haematology Lead (Professor of Thrombosis & Haemostasis at King’s Health care partners, based at St Thomas’ Hospital)

Professor Alun Davies & Mr Joseph Shalhoub, UK Vascular Surgery Leads (Consultant vascular surgeons, Imperial College London)

Mr Rufus Cartwright, UK Gynaecology Lead ( consultant gynaecologist Chelsea & Westminster Hospital, London)

Mr Sanjay Pandanaboyana, UK General Surgery Lead (HPB and Transplant Surgeon at Freeman Hospital)



Veeru Kasivisvanathan

Chief Investigator


Alexander Ng

Project team


Arjun Nathan

Project team


Kevin Keane

Project team


Aqua Asif

Project team


Simona Ippoliti

Project team


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