Avoiding Risks of Thrombosis and Bleeding in Surgery (ARTS) Trial

Inclusion Criteria: * Informed consent provided * Adult patients (≥18 years); * Undergoing elective abdominal or pelvic surgery at similar (and not high) risk of VTE and bleeding Exclusion Criteria: * Inability to provide informed consent * Patient with active bleeding/hemorrhage during the last 6 months if not expected to be treated by surgery planned * Lesion or condition if considered a significant risk factor for major bleeding a. This may include current or recent gastrointestinal ulceration, presence of malignant neoplasms at high risk of bleeding, recent brain or spinal injury, recent brain, spinal or ophthalmic surgery, recent intracranial haemorrhage, known or suspected oesophageal varices, arteriovenous malformations, vascular aneurysms or major intraspinal or intracerebral vascular abnormalities * Anticoagulant treatment, antiplatelet treatment or omega-3 dietary supplement during previous 7 days preceding surgery and/or requiring within 30 days post-surgery * Patient who had during previous 6 months or are expected require within 30 days post-surgery chemotherapy/radiation or hormone therapy for cancer * Known thrombophilia * Known bleeding disorder * Substantial liver impairment (for instance INR 1.4 or more during last 60 days) * eGRF \<30 mL/min/1.73 m2 * Platelet count \<100 × 109/L (that is, 100 000 mg/L) * Hb \<90 g/L (that is, \<9 g/dL) * ALT \>2 × upper limit of normal * Known allergy to apixaban * Taking strong inhibitors or inductors of both CYP 3A4 and P-glycoprotein, such as anti-seizure medications (e.g. phenytoin, fosphenytoin, carbamazepine), azole-antimycotics (e.g. ketoconazole, itraconazole), HIV-protease inhibitors (e.g. ritonavir, indinavir) and rifampicin * Concomitant procedures with high risk of VTE/bleeding * Previous VTE * Pregnant or breast-feeding female patients * Female participants who have had periods in the last 12 months and who are not using highly reliable contraception: (i) combined (estrogen and progestogen containing) hormonal contraception associated with inhibition of ovulation (oral, intravaginal, transdermal); ii) progestogen-only hormonal contraception associated with inhibition of ovulation (oral, injectable, implantable); iii) intrauterine device (IUD); iv) intrauterine hormone-releasing system (IUS); v) bilateral tubal occlusion; vi) vasectomized partner; and vii) sexual abstinence from heterosexual intercourse during the entire period of risk associated with the study treatments * Previous randomization in this trial * Any reason why, in the opinion of the investigator(s), the patient should not participate