A fatal case of extensive gastrointestinal necrosis due to portal and mesenteric vein thrombosis in the post-acute phase of COVID-19.

Portal vein thrombosis (PVT) is considered a relatively rare thrombotic complication in coronavirus disease 2019 (COVID-19). Most reported cases of PVT develop within 2 weeks from COVID-19 onset. We report a fatal case of extensive gastrointestinal necrosis due to portal and mesenteric vein thrombosis approximately 6 weeks after the onset of critical COVID-19. Excessive elevation of his plasma D-dimer level had continued for weeks during the hospitalization contrary with improvement of respiratory failure. Thrombotic complication should be cautiously paid attention even in the post-acute phase of COVID-19, especially in patients with persistent elevation of plasma D-dimer level.