ABSTRACT
Background: Pulmonary fissures are invaginations of the visceral pleura that extend from the outer surface of thelung into its substance. The fissures are grouped into normal and accessory fissures . The oblique fissure andhorizontal fissures are the normal pulmonary fissures which may be complete, incomplete or absent. Incompletepulmonary fissures are considered to be markers of collateral ventilation. They play a significant role indetermining clinical response following valve replacement surgery in emphysematous patients. The Accessoryfissures occurring within an individual lobe may be confused with other lesions such as linear atelectasis,pleural scar. Knowledge of the variations in the pulmonary fissures is useful for clinical interpretation. It is inthis regards that this study was undertaken to assess the morphology of pulmonary fissures.Materials and methods: The study was conducted on 60 formalin preserved adult human lungs (32 right, 28 left)of unknown age and sex obtained during dissection of embalmed cadavers for undergraduate teaching inDepartment of Anatomy, Rajarajeswari medical college and hospital. The anatomical classification proposed byCraig and Walker is followed to determine the completeness of pulmonary fissures . Four grades of fissures havebeen described. Grade 1- complete fissure with entirely separate lobes. Grade 2- complete visceral cleft butparenchymal fusion at the base of the fissure. Grade 3 - visceral cleft evident for a part of the fissure. Grade 4 -complete fusion of lobes with no evident fissure line. The data was tabulated and analysed using descriptivestatistics. The study was undertaken after obtaining approval from the institutional ethics committee.Results: Oblique fissure was incomplete in 13.33% of the right lungs while horizontal fissure was found to beincomplete in 30% of the right lungs. Horizontal fissure was found to be absent in 2 (3.33%) of the right lungs. Asuperior accessory fissure in the lower lobe separating the upper part of the lobe from the rest of the basalsegments was found in one right lung .Conclusions: The present study shows that the horizontal fissure is more frequently incomplete or absent whencompared to the oblique fissure in the right lung. Superior accessory fissure in the lower lobe of a right lung wasobserved in 1 (1.66%) specimen. Knowledge of the varying degrees of completeness of pulmonary fissures andaccessory fissures is essential to avoid misinterpretation of radiological signs