VARIATION IN LOBES AND FISSURES OF LUNG

Address for Correspondence: Dr. Jaideo Ughade, Associate professor, department of Anatomy, Late Lakhiram Agrawal Memorial Government Medical College, Bendrachua, Raigarh 496001 E-Mail: drjaideoughade@gmail.com Introduction: Lungs are the paired vital organs meant for respiration situated in the thoracic cavity on either side of the heart. The right lung is divided into supe-rior, middle & inferior lobes by oblique and horizontal fissure. While the left lung is divided into supe-rior & inferior lobes by an oblique fissure. The fissures permit distension of the lobes during respiration. The fissures may be complete, incomplete or absent. Aim: To find out the variations in fissures and lobes along with their patterns, in human lungs; collected from cadavers. Result: Out of 50 right lung specimen, the horizontal fissure was absent in two cases whereas the horizontal fissure was incompletely seen in 18 specimens. Incomplete oblique fissure was seen in 7 right sided lungs. We reported accessory fissures and accessory lobes in 14 specimens. The oblique fissure was absent in 4 left lungs and it was incomplete in 14 lungs. Accessory fissures and lobes were present in 8 specimens. Conclusion: Knowledge of any variations is necessary in performing segmental resection and lobectomy. Accessory fissures indicate persistence of prenatal fissures.

ward on the costal surface, continue across the diaphragmatic surface & ends below the hilum on to the medial sur-face.Horizon-tal fissure is present only in the right lung.It starts from oblique fissure, runs laterally & transversely over the costal surface then to the anterior margin &finally back to the hilum [1].The fissures permit distension of the lobes during respiration [2].The fissures may be complete, incomplete or absent.
Lungs are the paired vital organs meant for respiration situated in the thoracic cavity on either side of the heart.The right lung is divided into supe-rior, middle & inferior lobes by oblique and horizontal fissure.The left lung is divided into supe-rior & inferior lobes by an oblique fissure.The oblique fissure cuts the vertebral border of both lungs at the level of 4th or 5th thoracic spine.The oblique fissure runs down When the lobes of the lung are attached with each other only at the hilum by the pulmonary blood vessels and bronchi, the fissures are said to be complete.When the fissures are partly fused by parenchymal tissue between the lobes they are incomplete.Fissures assist in locating the bronchopulmonary segments [3].Knowledge of such variations is necessary in performing segmental resection and lobectomy.Accessory fissures indicate persistence of prenatal fissures.An incomplete fissure may cause post operative air leakage [4].Present study was conducted to note the variations in fissures and lobes of the lung in human cadavers and compare the findings with previous studies.Aim and objectives: To find out the variations in fissures and lobes along with their patterns, in human lungs; collected from cadavers.
A descriptive study to assess the variations in presence and completeness of fissures and lobes of the lung in human cadavers was conducted in the Department of Anatomy of Government medical colleges of Raigarh, Nanded and Yavatmal over a period of four years.Formalin fixed cadaveric lungs were collected while doing undergraduate dissection classes.Total number of speci-mens examined was 100 (50 of right side and 50 of left side).Variations in the form of complete, incomplete, absent, accessory fissure and lobe, if any were noted.The lobes and fissures of the lungs were observed for presence of variations in morphological features (i.e.complete, incomplete or presence, absence) and presence of any variant fissure, accessory fissure was noted and specimens were photographed.

MATERIALS AND METHODS
Among the total 100 specimens, 50 were of right side and 50 were of left side.The laterality was judged based on the hilar structures.Right lung: Out of 50 right lung specimen, the horizontal fissure was completely absent in two cases whereas the horizontal fissure was incompletely seen in 18 specimens.Complete absence of oblique fissure was not seen in any case out of 50 right lung specimens.Incomplete oblique fissure was seen in 7 right lungs.We reported

RESULTS
Accessory fissures and accessory lobes in 14 specimens.
Left lung: The oblique fissure was absent in 4 left lungs and it was incomplete in 14 lungs.Accessory fissures and lobes were present in 8 specimens.

Fig. 4 :Fig
Fig. 4: Accessory fissure and lobe on diaphragmatic surface of lung.

Fig
Fig. 7: Incomplete fissure not cutting the parenchyma of lung.
The percentage of variations was higher in the study conducted by Dutta et al.The presence of accessory fissure was noted in 38% specimen of right side and 32%specimen of left side by Ambali MP et al[8],Azmera  Gebregziabher et al [9]  showed presence of accessory fissure and accessory lobe in 2 lungs (8.69%) out of 23 right lungs.Accessory fissure was noted in 3 (15%) left lung specimens.We reported Accessory fissures and accessory lobes in 14 right sided specimens and accessory fissures and lobes were present in 8 left sided specimens.The mucosal linings of the bronchi and the epithelial cells of the alveoli are endodermal in origin.The vasculature, muscles & cartilage of the bronchi are derived from mesoderm.Lung bud appears as an outgrowth from the ventral wall of the foregut which bifurcates into right and left primary bronchial buds.The right bronchial bud branches into three secondary bronchial buds while the left one branches into two.At about 6th week of intrauterine life, the secondary bronchial buds branch into tertiary bronchial buds to form bronchopulmonary segments.The spaces between bronchopulmonary segments get obliterated except along the line of division of principal bronchi where deep complete fissures remain dividing the right lung into 3 lobes and left lung into 2 lobes.These fissures are oblique and horizontal in position in right lung where as only in oblique position in left lung[10].Incomplete or absence of oblique and horizontal fissures could be due to defective obliteration of these fissures either completely or incompletely whereas accessory fissures may be present due to non obliteration of spaces which should normally get obliterated[11].The percentage of variations in lobes and fissures in present study were similar to the study conducted by Varalakshmi et al.

Table 1 :
Showing the Percentage of lobes in the present study.

Table 2 :
Showing the present study findings while comparing with previous studies.
M Ughade, Poorwa B Kardile, Pawan R Tekade.VARIATION IN LOBES AND FISSURES OF LUNG