Regenerative capacity of lung parenchyma after necrotising pneumonia in childhood - longterm observational data

<bold>Background:</bold> Necrotising pneumonia (NP) is a rare but severe complication of pediatric community-acquired pneumonia (pedCAP). Surgical treatment is still preferred in some centres. Studies on the regenerative capacity of the affected lung parenchyma after conservative treatment of NP in children are lacking. <bold>Methods:</bold> Retrospective, monocentric analysis of children with NP treated between 09/2017 and 01/2024 in our center. The focus is on the evaluation of chest CT (CCT) at diagnosis and CCT or chest-x-ray at the latest follow-up (FU). <bold>Results:</bold> 19/218 children with complicated pneumonia had NP confirmed by CCT. Thereof n=3 were excluded from analysis due to previous surgical resection. N=16 were included (median age 3.0 yrs; IQR 2.3-5.6; 50% female). The main initial CCT findings were consolidations with necrotic and cystic lesions, and pneumothoraces. 63% had concomitant empyema, 69% pneumothorax and 56% persistent bronchopleural fistula (pBPF). All were treated with antibiotics, chest tubes (median 3 chest tubes/child, IQR 2-4, mean duration of 30 days, IQR 11-34, from first insertion to removal of last) and, in case of pBPF temporary interventional bronchus occlusion was performed. N=12 (75%) had at least one CCT at FU. After a mean of 128 days (IQR 94-148), there was an almost complete regression of the initial findings with unremarkable parenchyma and only mild ventilation disorders, minor scarring changes, and residual densification in all patients. At FU all were respiratory asymptomatic. <bold>Conclusion:</bold> The lung parenchyma of children with necrotizing pneumonia shows a high regenerative capacity. A primarily conservative and thus tissue-preserving therapy is justified.