Haemoperitoneum caused by spontaneous haemorrhage of the greater omentum: a rare complication occurring in a patient with severe SARS-CoV-2 infection.

Haemorrhagic events in patients diagnosed with coronavirus disease 19 (COVID-19) are infrequent but reports have accumulated since the beginning of the pandemic. The pathophysiological mechanisms are unclear, but endothelial damage secondary to systemic vasculitis and the onset of anticoagulation therapy, both associated with severe forms of the infection, have been proposed to play a role in the development of this complication. We present the case of a 66-year-old man who presented to the emergency department with acute abdominal pain, hypotension and decrease of consciousness, a few hours after being discharged after a prolonged hospitalisation of 26 days due to severe SARS-CoV-2 pneumonia. Initial resuscitation was carried out and, when haemodynamic stabilisation was achieved, a computed tomography scan showed contrast extravasation at the topography of the greater omentum. Urgent angiography revealing contrast extravasation originating in a pseudoaneurysm dependent on the right gastroepiploic artery was done, and embolisation with cyanoacrylate was performed at the bleeding point. Owing to persistent haemodynamic instability despite angiographic treatment and aggressive resuscitation, emergency laparotomy was indicated. Partial resection of the greater omentum was carried out and histopathologic examination showed a 5cm×4cm×6cm haematoma, with no signs of abnormalities such as aneurysm or malignancy. No rebleeding occurred. Spontaneous haemorrhage of the greater omentum associated with haemoperitoneum is a serious condition, with reported mortality rates exceeding 30%. This case highlights a very infrequent but potentially life-threatening complication in a patient diagnosed with COVID-19 on anticoagulation therapy.