A Series of 40 Congenital Lung Malformation Cases and the Informative Value of CPAM Lesion Ratios.

Introduction: In this single-center retrospective analysis, we present case data and insights gathered over the past eight years. Additionally, we computed postnatal, pre-therapy lesion-to-lung ratios of Congenital Pulmonary Airway Malformations (CPAMs) to retrospectively assess potential outcome prediction using lesion-to-lung ratios.

Methods: Data were collected between 2015 and 2022. Information such as chosen therapy, surgical duration, postoperative hospital stay, and follow-up was obtained from electronic case records. Pre-therapy pulmonary lesion volumes [mm³], lesion-to-ipsilateral-lung ratio, and lesion-to-both-lungs ratio of CPAMs were retrospectively calculated from computed tomography images using specialized software.

Results: Of the 40 identified cases, 27 had CPAM, 7 had pulmonary sequestration, 4 had bronchogenic cysts, and 2 had congenital lobar emphysema. Histological examinations of resected specimens revealed no malignancy. For CPAMs, the median surgery age was 7 months (interquartile range (IQR): 0.45-11), averaging 9.54 ± 15.01 months. The CPAM surgery lasted on average 126 ± 53 min (median 124 min (IQR 108-172)). The mean length of hospital stay was 6 ± 1.41 days for thoracoscopic surgery and 17 ± 18.23 days for open surgery. No clear link was found between the lesion ratio and management choice or surgical length. Notably, larger lesions tended to result in longer postoperative stays. CPAMs with a lesion-to-ipsilateral-lung ratio of ≤0.11 were asymptomatic.

Discussion and conclusions: If patients present no symptoms, mild symptoms, or smaller CPAM lesions, "wait and watch" and a CT scan of the thorax up to approximately six months of age remain a reasonable approach. The true risk of malignancy remains ambiguous, especially since there was no evidence of malignancy in our biopsies. On the other hand, prophylactic surgery before symptoms arose led to earlier discharge and overall low intraoperative complications compared to symptomatic counterparts. Ultimately, the adopted therapy pathway remains a parental choice. For CPAMs, an increased lesion-to-lung ratio correlated with extended hospital stay and symptomatic presentation. However, there was no cut-off value for conservative or surgical treatment.