Overview In Situ Thrombolysis With tPA and Inflow Perfusion Analysis in Patient With Severe Covid-19 Infection Status: Completed Trial end date: 2021-03-30 Target enrollment: Participant gender: Summary To estimate the pulmonary response microvascular thrombosis in critical patients due to SARS-Cov-2., at the Hospital General de México "Dr. Eduardo Liceaga", a 15 patients compassionate treatment study was authorized and approved by the ethics and research committee DI-222-2020. Because of the severity of the illness the legal representative sign informed consent in all the patients for performing in-situ thrombolysis with alteplase selectively by catheter in each main pulmonary artery, under fluoroscopic guidance and acquiring images with the iFlow software to assess immediate and post-procedure response. Phase: N/A Details Lead Sponsor: Grupo Mexicano para el Estudio de la Medicina Intensiva