Ultrasound features of abdominal thrombosis in COVID 19 patients.

PURPOSE: Abdominal thromboses are a poorly characterized thrombotic complication of COVID-19. The aim of this paper is to report multimodality ultrasound imaging findings of the abdomen in evaluation of thrombotic lesions in hospitalized patients with COVID-19. PATIENTS & METHODS: In this retrospective observational study, patients admitted to a single University Hospital from April 1 2020 to April 30, 2022, who tested positive for COVID-19 and developed acute abdominal pain over the course of hospitalization were included. Abdominal ultrasound imaging studies performed in these patients were reviewed, including B mode ultrasound (BMUS), color-coded Doppler ultrasound (CCDS) and contrast enhanced ultrasound (CEUS). Thromboembolic findings on CT were also recorded. RESULTS: Finally, 13 cases of abdominal thrombosis in 226 Patients with COVID 19 infections were included (mean age, 56.69±8.97 years; 10 men, 3 women). Thromboembolic events including: iliac thrombosis (n = 4), portal venous (PV) thrombosis (n = 3), superior mesenteric vein (VMS) thrombosis (n = 2), inferior vena cava (IVC) thrombosis (n = 5) and inferior mesenteric vein (VMI) thrombosis (n = 1). In all cases of abdominal thrombosis, during high resolution BMUS scan, intra-luminary hypoechogenic appositional thrombi could be detected. Meanwhile blood flow with reduced speed less than 20 cm/s could be observed by CCDS. High arterial flow speed was a sign of collateral flow changes with diffuse venous dilatation. On CEUS, changes of the microcirculation of the liver, spleen, kidneys or small bowel by infarctions or micro-emboli could be detected. In 3 cases of PV thrombosis and in 2 cases of IVC thrombosis, catheter interventions were successful performed for recanalization without relevant lumen reduction afterwards. In other cases, without interventional procedure, partial recanalization happened with venous flow speed over 15 cm/s and lumen reduction more than 50% . CONCLUSIONS: Our study highlights those thromboembolic complications can be seen in hospitalized patients with COVID-19. Multimodality ultrasound examinations is helpful for early and accurate diagnosis of these complications.