<qa>  What is the aim of this clinical trial?Weight loss after bariatric surgery can putatively alter drug disposition of rivaroxaban. This may be due to an altered intestinal adaptations several months after the surgical procedure. The aim of this clinical trial is to investigate pharmacokinetic and pharmacodynamic parameters after single application of 10 mg rivaroxaban in patients with prior bariatric intervention Roux-en-y-gastric bypass or sleeve gastrectomy 6-8 months ago. PKPD parameters will be assessed during 12 hours after application of rivaroxaban. 