Natural courses and prognostic factors of pulmonary underdevelopment except for congenital diaphragmatic hernia

Abstract

Purpose: Pulmonary underdevelopment is one of the pulmonary causes of neonatal mortality, which is categorized into pulmonary agenesis, pulmonary aplasia, and pulmonary hypoplasia. Congenital diaphragmatic hernia is a well-known cause of pulmonary hypoplasia; however, further studies are needed for other etiologies. Patients with pulmonary underdevelopment show varying degrees of clinical severity. Most patients with pulmonary underdevelopment have respiratory distress at birth, while a few have only mild symptoms. Our study investigated the natural course and prognosis of pulmonary underdevelopment by analyzing multiple cases from a single tertiary medical center. Methods: A retrospective review was conducted on patients diagnosed with pulmonary hypoplasia and agenesis from January 2000 to August 2019. Cases were extracted from the clinical database of Seoul National University Children's Hospital by searching for keywords related to pulmonary underdevelopment. Results: A total of 28 patients were identified. Four patients had pulmonary agenesis, and all were idiopathic. Twenty-four patients had evidence of pulmonary hypoplasia with diverse causes. The median age at diagnosis was 11.5 days (range, 1-240 days) and the mean gestational age was 35 weeks 2 days± 3 weeks 6 days. Twenty patients received ventilator care and 11 had various degrees of pulmonary hypertension. The long-term survival rate was 50%. The median age of death among pulmonary hypoplasia patients were 11 days (range, 1-730 days). All patients without ventilator care survived. The incidence of ventilator care, pneumothorax, and pulmonary hypertension were significantly higher among patients who died. Conclusion:The prognosis of pulmonary underdevelopment depends on the severity of respiratory distress and pulmonary hypertension in earlier life. Patients with severe distress appear to have severe degree of pulmonary hypoplasia. Patients without ventilator support in the neonatal period survived without significant morbidities.

Clinical and imaging features of presumptive congenital pulmonary underdevelopment with complications in two dogs

“…Thus, the diagnosis of congenital pulmonary underdevelopment only by radiographs, without CT scans, which provide a detailed description of the bronchial tree, parenchyma and vasculature, was limited. Among the complications of congenital pulmonary underdevelopment, the management of pulmonary hypertension plays an essential role in prolonging the survival period in human medicine 6,17,19,26,27 . Follow‐up with yearly echocardiography evaluation should be considered for timely detection and treatment of complications, especially pulmonary hypertension secondary to congenital pulmonary underdevelopment 6,25 .…”

“…Congenital pulmonary underdevelopment results in a lack of the total number of normal pulmonary vessels and alveoli. Owing to this insufficiency, high arterial pressure is required to compensate for the deficit in the oxygen exchange capacity of the alveoli 17 . In addition, the shortage of the pulmonary artery results in the redirection of blood flow towards the remaining normal pulmonary blood vessels 14,19 .…”

“…This remodelling of the pulmonary arterioles would result in increased resistance in the pulmonary vasculature and pulmonary hypertension 14,27 . Approximately one‐fifth of patients with pulmonary underdevelopment have varying degrees of pulmonary hypertension, which negatively impacts the prognosis in human medicine 17,26 . A definitive diagnosis of pulmonary hypertension requires right heart catheterisation, but as there are clinical limitations, evidence of elevated pulmonary arterial blood pressure is measured indirectly through echocardiography 15 .…”

“…The commonly used histological methods are the lung weight to bodyweight ratio and the radial alveolar count defined as the number of alveoli crossing a line drawn from a respiratory bronchiole centre to the nearest and definitive connective tissue septum 16 . These histopathologic methods are related to the functional parenchymal volume of the lung, and based on this principle, in human medicine, congenital pulmonary hypoplasia can be diagnosed through indirect measurement of the affected lung parenchymal volume through CT, ultrasound, MRI and comparison with normal contralateral lung lobes 6,9,17–21 . Even in veterinary medicine, there is a report of presumptive diagnosis through the CT scan without performing a histopathologic examination 10 …”

“…16 These histopathologic methods are related to the functional parenchymal volume of the lung, and based on this principle, in human medicine, congenital pulmonary hypoplasia can be diagnosed through indirect measurement of the affected lung parenchymal volume through CT, ultrasound, MRI and comparison with normal contralateral lung lobes. 6,9,[17][18][19][20][21] Even in veterinary medicine, there is a report of presumptive diagnosis through the CT scan without performing a histopathologic examination. 10 The hypoplastic lung lesions identified in these cases can be considered congenital lesions; the acquired lung diseases may also be able to develop pulmonary hypoplasia.…”