Clinical outcomes of pulmonary agenesis: A systematic review of the literature

Introduction: Pulmonary agenesis is a complete absence of the pulmonary parenchyma, airways, and vasculature unilaterally or bilaterally. Although bilateral cases are lethal, the outcome of unilateral cases remains not well described. We performed a comprehensive literature review to assess the clinical features of pulmonary agenesis. Methods: Four database sources were searched on October 10, 2021 and two cases were included from our institution. Studies related to the clinical impact of comorbidity and intervention on the survival outcome in pulmonary agenesis were included for full-text review. Results: We identified 259 patients—with right-sided (59%), left-sided (34%), and bilateral agenesis (7%)—among 195 articles and our two cases. Additional anomalies included cardiovascular (40%), skeletal (30%), gastrointestinal (20%), tracheal (20%: all stenoses), and genitourinary (14%) anomalies. Fifty-seven (24%) individuals in unilateral pulmonary agenesis had isolated disease. Outcomes related to survival were not uniformly reported, but the 2-year overall survival rate of unilateral agenesis was 62% and no subsequent death was reported until 13 years of age. The right-sided agenesis was more frequently associated with tracheal stenosis (27% vs. 11%, p = 0.003) than the left-sided disease. A multivariable analysis indicated that tracheal stenosis (hazard ratio [HR]: 2.2, 95% confidence interval [CI]: 1.3–4.1, p = 0.003) and gastrointestinal anomalies (HR: 2.0, 95% CI: 1.1–3.3, p = 0.010) were prognostic factors for mortality. Conclusions: The poor prognostic factors were tracheal stenosis, right agenesis, and gastrointestinal anomalies. Treatment for these comorbidities is a key point for improving the survival of unilateral pulmonary agenesis.