A Cadaveric Study of Variations in Lung Fissures and Drainage Patterns of Pulmonary Veins at the Hilum With Its Clinical Implications.

Introduction The human lungs are located in the pleural cavity, divided by fissures into lobes, facilitating respiration movements. It acts as a barrier to prevent the spread of infection to adjacent lobes. The pulmonary hilum in each lung contains pulmonary vessels, bronchial vessels, and the bronchus. Pulmonary venous drainage variations are expected to be significant in diagnostic and therapeutic procedures. The present study aims to study the variant pattern of the lung fissures and the drainage pattern of the right and left pulmonary veins at the pulmonary hilum. Methodology The descriptive study was conducted on 75 lungs in the Department of Anatomy after obtaining ethical approval from Vinayaka Mission's Medical College and Hospital, Karaikal, India. A few lung specimens were procured from the government hospital, Karaikal. All the lung specimens belonging to adults of unknown age and gender collected over three years were included in our study. Lungs with evident pathological conditions, damage, surgical resections, and metastatic disease were excluded from the study. The pattern of oblique and horizontal fissures and accessory fissures was studied on both the right and left lungs. These fissures were categorized based on the Craig and Walker classification, a widely accepted system in pulmonary anatomy. The hilar structures were dissected on both the right and left lungs, the pulmonary veins were picked up, the different drainage patterns of pulmonary veins at the hilum were studied, and the results were expressed in percentage. In addition, the presence of an accessory vein and anomalous unilateral single pulmonary vein was documented. Results Out of 35 right lungs, incomplete and absent oblique fissures were observed in 10 (28.57%) and four (11.43%), and incomplete and absent horizontal fissures were observed in 12 (34.29%) and seven (20%) of the specimens. Out of 40 left lungs, incomplete and absent oblique fissures were observed in 13 (32.5%) and three (7.5%) of the specimens. Superior and inferior accessory fissures were present in five (14.29%) and four (11.4%) of the right lungs, and the left minor fissures were seen in 15 (37.5%) of the specimens. Different patterns of pulmonary venous drainage were reported in our study, and variations were observed in 52% of the specimens. A single unilateral pulmonary vein was documented in two (5.71%) and 14 (35%), and the accessory vein was noted in seven (20%) and two (5%) of the right and left lungs, respectively. These findings underscore the importance of understanding the variant patterns of pulmonary veins and the presence of accessory veins in the context of cardio-thoracic surgeries. Conclusions As revealed by our study, the variations in the pulmonary veins and fissures are paramount in the surgical field. These findings will reassure and instill confidence in surgeons and radiologists, enabling them to diagnose and perform cardio-thoracic surgeries with a strong foundation of anatomical knowledge.