To evaluate appropriateness of enoxaparin bioavailability at two different sites of subcutaneous administration (arms or abdomen) in primary or secondary prevention of thromboembolism in a population of patients with severe obesity

Inclusion Criteria:• age >18 years,

• BMI >40 kg/m2
• indication to primary or secondary thromboprophylaxis (Padua Score > 4), as clinical practice

Exclusion Criteria:• indication to full dose anticoagulant,

• creatinine clearance <30 mL/min (based on Cockcroft-Gault equation using adjusted body weight),
• pregnant women,
• low platelet count (<50.000/microL or <100.000/microL plus additional risk factors for bleeding),
• active bleeding,
• active gastroduodenal ulcer,
• severe bleeding diathesis,
• recent/planned/emergency high bleeding-risk surgery/procedure,
• major trauma,
• acute intracranial hemorrhage,
• bleeding within the three months prior to admission,
• known hypersensitivity to enoxaparin (e.g. pruritus, urticaria, anaphylactic/anaphylactoid reactions),
• history of immune mediated heparin-induced thrombocytopenia (HIT),
• severe uncontrolled hypertension,
• diabetic or hemorrhagic retinopathy,
• concurrent administration of subcutaneous drugs (i.e. insulin, GLP-1 receptor agonists, etc.).

Prospective observational study, multicentric. Target population: Patients with BMI 40 kg/m2 hospitalized, candidates for anticoagulation therapy in prophylaxis (PADUA score 4).