Structural Anatomy of the Lung Hilum: A Gateway to Clinical Understanding

Introduction: The lung hilum, which has considerable asymmetry between the right and left sides because of mediastinal structures, is a crucial anatomical gateway where bronchi, pulmonary vessels, lymphatics, and nerves converge. Its intricate structure is essential for radiology and thoracic surgery, but it is also susceptible to diseases. Methods: A preserved human cadaver from a voluntary donation program (age 60, no pulmonary pathology) was used for a descriptive anatomical study. The cadaver was placed supine after ethical clearance. Lung mobilization followed sternotomy and midline thoracotomy. The bronchi, pulmonary arteries/veins, and lymph nodes were revealed by carefully dissecting the connective tissue surrounding the hilum on both sides. Findings: The superior lobar bronchus (eparterial) was always the most superior, followed by the pulmonary artery, and the right hilum was bigger and more vertically orientated. Most anterior was the superior pulmonary vein. There were many lymph nodes, particularly in the vicinity of the bronchus intermedius. The pulmonary artery was the most superior structure, arching over the main bronchus, which was positioned posteroinferiorly; the left hilum was smaller and orientated transversely. The artery is anterior-inferior to the superior pulmonary vein. Compared to the right, there were fewer and more widely spaced lymph nodes. Discussion: Based on mediastinal constraints and embryological development, this study demonstrates a clear hilar asymmetry. Important surgical landmarks are the left arching pulmonary artery and the right eparterial bronchus. The results are consistent with classical anatomy, but because of possible variations, they emphasise the necessity of preoperative imaging. The hilum's clinical significance is highlighted by its susceptibility to infections, granulomatous diseases, and cancers. Thorough understanding of the hilum is still necessary for safe radiological and surgical procedures.