Post COVID-19 pneumo-hematocele: clinical presentation and treatment pathway

Abstract

Objectives The appearance of characteristic pulmonary lesions has been noted after COVID-19, being described as post-COVID-19 pneumo-hematocele. The aim of this study is to describe the clinical, histopathologic, and imaging features of pneumo-hematocele and to suggest a treatment algorithm for these patients. Methods A retrospective study was performed in patients admitted with a diagnosis of SARS-CoV2 infection from March 2020 to September 2021 who presented a pneumo-hematocele on imaging studies. Clinical and demographic variables were recorded, and CT scans were analyzed. A secondary analysis was performed to estimate the risk provided by the pneumo-hematocele diameter of developing pneumothorax. Results 37 patients were diagnosed with pneumo-hematoceles, 97.3% were males with a median age of 41 ± 13 years and 51% were smokers. The mean diameter of the pneumatocele was 6.3 ± 2.8 cm; they were more common on the subpleural surface and in the inferior lobe. Thirty patients had ruptured pneumo-hematoceles and developed pneumothorax (81.1%); a total of 26 patients required surgery (70.3%). Lesions measuring 5 cm had a high risk of rupture (OR 6.8, CI 95% 1.1–42); those measuring 3 cm were prone to this complication. For each centimeter that the pneumo-hematocele diameter increases, the OR for rupture increases 1.5. Conclusions It appears that post-COVID-19 pneumo-hematocele occurs secondary to encapsulation of blood accumulation inside the lung, as a result of micro-capillary bleeding, with partial reabsorption of blood and subsequent air filling. We recommend surgery for patients with pneumo-hematoceles of 5 cm and those with persistent lesions of 3 cm. Trial registration Clinical Trial Registration: NCT05067881.

Histopathological pulmonary findings of survivors and autopsy COVID-19 cases: A bi-center study

“…If it is filled with blood, it is called pneumo-hematocele. [11,15,45] Some authors report similar findings and describe the airspace as a bulla rather than a pneumatocele. [46] Most pneumo-hematoceles occur in relatively young male patients (most often in the age of [30][31][32][33][34][35][36][37][38][39][40] and generally in those with the moderate and severe disease around day 20 after diagnosis.…”

“…Pneumo-hematoceles can present with symptoms due to pneumothorax, lung displacement, and rupture or as asymptomatic lesion in imaging studies. [ 11 ] The precise pathogenesis of pneumo-hematatocele remains uncertain. Most authors agree with the theory that after infectious pneumonia the inflammatory and airway secretions form a bronchial valve, which allows the air to enter but not to come out, this results in a rupture of the airways and formation of air-filled cysts.…”

“…[ 16 ] Moreover, in some instance the pneumatocele can dissect through the pleural membrane causing pneumothorax. [ 11 , 14 , 15 , 49 ]…”

“…Most authors agree with the theory that after infectious pneumonia the inflammatory and airway secretions form a bronchial valve, which allows the air to enter but not to come out, this results in a rupture of the airways and formation of air-filled cysts. [11,[14][15][16]45] Another theory suggests that inflammation and necrosis of a portion of the airway results in focal collections of air in the interstitial tissue and formation of grossly identifiable pneumatocele. [16,47] Coronavirus targets alveolar epithelial cells, which together with cytokine storm make the alveoli vulnerable to rupture with subsequent air leakage.…”

“…[9,10] Recently, the appearance of characteristic pulmonary lesions such as pneumo-hematocele or giant bulla has been noted. [11][12][13][14][15][16] There have been published many papers documenting postmortem pathology and discussing pathophysiology in COVID-19. [1,3,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] However, the number of research analyzing the histopathologic changes in the lungs of patients with COVID-19 infection history who survived and developed pulmonary complications is still insufficient.…”