Natural Fissures of Lung- Anatomical Basis of Surgical Techniques and Imaging

Background: The fissures in lung enhance uniform expansion. These fissures may be complete, incomplete or absent. A detailed knowledge of variations of classical and accessory fissures is necessary for proper radiological interpretation. It is a guide to cardiothoracic surgeons performing segmental lung resections, lobectomies to have an uncomplicated perioperative outcome. So, the cadaveric study was done to note the morphological variation of the fissures of lung in eastern Indian population and compare it with previous studies. Methods: 102 lungs obtained during dissection of formalin fixed cadavers in Calcutta National Medical College, Kolkata and preserved in 10% formalin were thoroughly studied to note every morphological details of fissures present in the lungs. Results: 44% of left lungs had classically complete oblique fissure compared to 26.92% on the right. No oblique fissure could be detected in 8% lungs of left and 11.54% of right side. Horizontal fissure was completely absent in 34.6%. Various degree of parenchymal fusion was more common on the right side. None of the oblique fissures had uniform depth. Conclusion: Comparison with other studies shows wide regional variations in morphological patterns of lung fissures, implying environmental and genetic factors in its development .Present study unfolds that parenchymal fusion of various extent is a very common entity of oblique fissure of lung. So, more lung parenchyma has to be dissected to reach the bronchi and pulmonary arteries during partial lung resection which naturally might lead to peroperative hemorrhage and more postoperative complications. This knowledge of anatomy of fissures of lung may also help clarifying confusing radiographic findings.