MORPHOMETRIC STUDY OF HILAR ANATOMY, FISSURES AND LOBES OF HUMAN LUNG – A CADAVERIC STUDY

Gomathi Ramakrishnan*, Dhivyalakshmi Gnanasekaran, Aruna S. and Murugesa Bharathi O.

ABSTRACT

Background: The lungs situated in the thoracic cavity on either side of the mediastinum are the vital organs of respiration. Knowledge about the fissures, lobes, and hilar anatomy of the lung is essential for surgeons during the resection of lung segments in lung cancer, for radiologists to avoid misinterpretation of the normal anatomical variations of lungs as lung pathologies. The knowledge of dimensions of principal bronchi is of significant use in bronchoscopy and also in evaluating the etiology of severe pulmonary diseases. Objectives: To study the variations in lobes, fissures, and hilar structures and to measure the luminal diameters of the principal bronchus at the bifurcation and the hilum in both lungs. Method: It is a cross-sectional descriptive study. Twenty-five lung specimens along with trachea & principal bronchus from the routine autopsy were studied. Variations in the lung, principal bronchi, and hilar structures were noted. Vertical and anteroposterior diameters of principal bronchi were taken at the tracheal bifurcation and hilum. Result: Among the fifty specimens, 10% had an accessory fissure, and 8% of right lungs had an absent horizontal fissure. In 14% of specimens, there was bifurcation of the pulmonary artery and in 22% there was bifurcation of the pulmonary vein just before entering the hila. In 12% of lung specimens, the principal bronchus is divided into lobar bronchi either at the level of tracheal bifurcation or just before entering the hilum. There was no progressive narrowing of principal bronchi on both sides but the luminal diameter of the left side bronchus was less compared to the right side. Discussion: The knowledge of these variations is essential to diagnose the site of lesions and the luminal diameter of bronchi is useful in diagnostic and therapeutic bronchoscopic procedures. Conclusion: This study will be helpful for clinicians, surgeons, and radiologists for diagnostic procedures using bronchoscopy, diagnosis & planning of treatment modalities like lung or segmental or lobar resection surgeries in various lung diseases.

Keywords: lung, principal bronchus, pulmonary artery, pulmonary vein.