Vascularization patterns of the upper lobes in the fetal population

The vascularization of the lung is predominantly provided by the pulmonary artery, which transports blood from the right ventricle to the pulmonary parenchyma. During fetal life pulmonary vascularization is more intense than in adults due to the phases of development: embryonic, pseudo glandular, canalicular, saccular, and alveolar. In the adult lung upper lobes, the main arteries are the apicoposterior branch and the anterior branch for the right upper lobe, and three branches (anterior, apicoposterior, and lingual) for the left upper lobe. This study focused on identifying the patterns of arterial branching in the upper lobes of fetal lungs. Seven fetal specimens were dissected, injected with latex, and fixed in formaldehyde. A predominance of vascularization was found in the upper lobes, with patterns identified as anterior, superior, posterior, and mixed. In the right upper lobes, the anterior pattern predominated in most cases, while greater diversity was observed in the left upper lobes, including anterior, posterior, superior, and mixed patterns. This study highlights the importance of understanding vascularization patterns in fetuses to improve surgical planning in neonates and infants, considering the high vascularization during pulmonary development. Despite the heterogeneity of the sample, which limits statistical precision, the findings provide valuable information to reduce complications in neonatal and pulmonary surgery. This study proposes a clear nomenclature that adheres to international standards to facilitate interpretation.