BACKGROUND: Histopathological analysis can provide additional clues in COVID-19 understanding . During the last year, autopsy reports have revealed that diffuse alveolar damage (DAD) is the most significant observed finding . The aim of this study is to review cases in the literature about COVID-19 autopsies that reported microthrombi in different organs .
METHODS: We performed a systematic literature review in PubMed, Virtual Health Library (VHL), and Google Scholar .
RESULTS: In total , 151 autopsies were included, and 91 cases presented microthrombi in the lung (73 %), heart (11.2 %), kidney (24 %), and liver (16.3 %). The age range was between 27 and 96 years . Males were 64.8% . The patients with microthrombi had more comorbidities such as arterial hypertension (62 %), obesity or overweight (64 %), diabetes mellitus type 2 (51 %), and heart disease (53 %). The most common histopathological changes found in patients with lung microthrombosis were DAD in exudative phase (78 %), pulmonary embolism (59 %), and lung infarct (81 %). Presence of microthrombi was associated with arterial hypertension (p <0.0001) and DAD in exudative and proliferative phases (p = 0.02).
DISCUSSION: The analysis of these results shows that microthrombi in COVID-19 autopsies may be found in different organs and are more frequent in patients with comorbidities, pulmonary embolism, and lung infarct.