TY - JOUR T1 - Radiological–pathological signatures of patients with COVID-19-related pneumomediastinum: is there a role for the Sonic hedgehog and Wnt5a pathways? JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00346-2021 VL - 7 IS - 3 SP - 00346-2021 AU - Elisa Baratella AU - Rossana Bussani AU - Fabrizio Zanconati AU - Cristina Marrocchio AU - Giudici Fabiola AU - Luca Braga AU - Serena Maiocchi AU - Giorgio Berlot AU - Maria Concetta Volpe AU - Edoardo Moro AU - Paola Confalonieri AU - Maria Assunta Cova AU - Marco Confalonieri AU - Francesco Salton AU - Barbara Ruaro Y1 - 2021/07/01 UR - http://openres.ersjournals.com/content/7/3/00346-2021.abstract N2 - Pneumomediastinum is a rare complication of acute respiratory distress syndrome (ARDS), when air leaks into the mediastinum. An increased pneumomediastinum incidence, of up to 5–13%, was reported during the coronavirus disease 2019 (COVID-19) pandemic [1, 2] and even occurred spontaneously without a history of mechanical ventilation [3], similarly to the previous severe acute respiratory syndrome (SARS)-1 [4]. Almost half of the 30 consecutive COVID-19 patients who had prolonged invasive mechanical ventilation had full-thickness tracheal lesions and pneumomediastinum [5]. Although pronation and high positive end-expiratory pressure levels were presumed to be the putative causes of pneumomediastinum [5], the mechanism of this COVID-19 complication remains unknown. We hypothesise that sonic hedgehog (SHH) and Wnt5a signalling, crucial pathways in tracheal morphogenesis, and repair/regeneration of cartilage lesions in adulthood [6, 7], could play a role in pneumomediastinum-related COVID-19 tracheal lesions.Pneumomediastinum is a rare complication of ARDS but is more common during #COVID19. The fibrous hyaline degeneration of the tracheal rings seen in this autoptic series is an original observation that has not been previously described in COVID-19 patients. https://bit.ly/3vxTQdeThe authors would like to thank Barbara Wade, contract professor at the University of Turin, for her linguistic advice. ER -