Pulmonary and systemic involvement of COVID‐19 assessed by ultrasound‐guided minimally invasive autopsy

Nunes Duarte‐Neto, Amaro; de Almeida Monteiro, Renata Aparecida; da Silva, Luiz Fernando Ferraz; Malheiros, Denise Maria Avancini Costa; de Oliveira, Ellen Pierre; Theodoro Filho, Jair; Pinho, João Renato Rebello; Soares Gomes‐Gouvêa, Michele; Salles, Ana Paula Moreira; de Oliveira, Ilka Regina Souza; Mauad, Thais; do Nascimento Saldiva, Paulo Hilário; Dolhnikoff, Marisa

AIMS: Brazil ranks high in the number of COVID‐19 cases and COVID‐19’s mortality rate. In this context, autopsies are important to confirm the disease, determine associated conditions, and study the pathophysiology of this novel disease. In order to follow biosafety recommendations, we used Ultrasound‐Guided Minimally Invasive Autopsy (MIA‐US) to assess the systemic involvement of COVID‐19 and present the results of ten initial autopsies. METHODS AND RESULTS: We used MIA‐US for tissue sampling of lungs, liver, heart, kidneys, spleen, brain, skin, skeletal muscle and testis for histology and RT‐PCR to detect SARS‐COV‐2‐RNA. All patients presented exudative/proliferative Diffuse Alveolar Damage. There were intense pleomorphic cytopathic effects on the respiratory epithelium, including airway and alveolar cells. Fibrinous thrombi in alveolar arterioles were present in eight patients and all patients presented a high density of alveolar megakaryocytes. Small thrombi were less frequently observed in glomeruli, spleen, heart, dermis, testis, and liver sinusoids. The main systemic findings were associated with comorbidities, age, and sepsis, in addition to possible tissue damage due to the viral infection such as myositis, dermatitis, myocarditis and orchitis. CONCLUSIONS: MIA‐US is safe and effective for the study of severe COVID‐19. Our findings show that COVID‐19 is a systemic disease with major events in the lungs and involvement of various organs and tissues. Pulmonary changes are the result of severe epithelial injury and microthrombotic vascular phenomena. These findings indicate that both epithelial and vascular injury should be addressed in therapeutic approaches.