Unilateral Absence of Main Branch of Pulmonary Artery

Background: unilateral absence of a pulmonary artery (uapa) is an uncommon anomaly with reported incidence of 1 in 200,000 young adults and a diverse clinical presentation. it may be diagnosed as an isolated congenital anomaly or in combination with other heart defects. the present study aimed to investigate the clinical course and characteristics of 40 patients with uapa the diagnosis of whom was first established in childhood or adulthood.materials and methods: from january 2002 to april 2021, 40 patients with uapa were diagnosed at our institution. the medical records of these patients were retrospectively reviewed in detail, and information covering the patients' demographics, associated anomalies, imaging studies, and operation data were elicited.results: according to the results, all 40 patients were between 2 months and 25 years old (mean age: 6.45 years) at the first presentation, weighing 4.70-59.00 kg (mean weight: 19.17 kg). regarding gender, 25 (62.5%) patients were female. left sided uapa was found in 60% (n=24) of cases, and 40% of patients had occult right pulmonary artery (rpa). moreover, a right-sided aortic arch was found in 4 (10%) patients. tetralogy of fallot was diagnosed in 16 patients, whereas complex cardiac anomalies were found in 13 cases.conclusion: clinicians should consider the undiagnosed cases of uapa, especially in adults with suspicious symptoms, such as unexplained hemoptysis. the application of different available imaging techniques for early diagnosis and treatment of isolated uapa cases is important to prevent the devastating complications of pulmonary hypertension and massive hemoptysis in the long term.