Abstract
We report a case of anticoagulation therapy complicated by a non-traumatic rectus sheath hematoma (RSH). RSH is a relatively rare occurrence caused by bleeding into the rectus sheath following the rupture of the superior and inferior epigastric vessels combined with a primary tear of the rectus muscle fibers. Herein, we report a rare presentation of RSH in a 73-year-old man taking the direct oral anticoagulant (DOAC) apixaban orally. The patient presented with sudden right abdominal pain after a severe cough, which worsened with cough and movement. The Fothergill and Carnett signs were positive. The platelet count, renal function test, and the prothrombin time/international normalized ratio were within the normal range. The activated partial thromboplastin time was 40.0 s, slightly longer than normal. Computed tomography (CT) of the abdomen and pelvis showed RSH, and DOAC therapy was temporarily discontinued. Subsequently, RSH resolution was confirmed via CT four weeks after the onset. DOACs are safer and more efficacious than warfarin for patients with non-valvular atrial fibrillation. However, RSH is a potential complication of anticoagulant therapy. This case report demonstrates that RSH should be considered in the differential diagnosis of sudden-onset abdominal pain and mass in patients on DOACs.