ABS ENCE OF RIGHT HORIZONTAL FISS URE AND LEFT OBLIQUE FISS URE IN A PAIR OF LUNGS – A CADAVERIC CAS E REPORT

Suranjana banik 1 , rajkumari ajita 2 and aribam jaishree devi 2 . 1. Second Year Post Graduate Trainee in MD (Anatomy), Regional Institute of Medical Sciences (RIMS), Imphal. 2. Professor, Department of Anatomy, RIMS Imphal. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 09 September 2018 Final Accepted: 11 October 2018 Published: November 2018


Introduction:
Situated on either sides of the heart and other structures in the mediastinum, and occupying the major part of the thorax, the pair of lungs act as the essential organ of respiration. Generally right lungs is divided into three lobes by one right horizontal and o ne right oblique fissure while the left lung is divided into two lobes by left oblique fissure. Variat ion in emb ryological origin may cause incomp leteness or absence of fissures and thus changes in lobar arrangements. Material&Method: During performing routine dissection for undergraduate students, this rare case was noticed in the lungs of a 58 years old formalin fixed female cadaver in the Department of Anatomy of Regional Institute of Medical Sciences, Imphal. The specimen was photographed and comparisons were made with normal ones. Result: The right lung showed the presence of a single fissure. The oblique fissure was present and it divided the lung into two lobes namely upper and lower lobe. However, horizontal fissure was absent. In the left lung, there was absence of the oblique fissure. Costal surface and structures passing through hilum were normal in both sides. Conclusion: The lung fissures enhance uniform expansion, and can be used as reliable landmarks in thoracic lesions. Surgically, the gradation of fissure is important for approaching the ligation of vessels and bronchi through the depth of the fissure. Knowledge of anatomical variation in fissures is important for segmental resections, lobectomies and radiological reporting of lung pathologies.

…………………………………………………………………………………………………….... Introduction:-
Situated on either sides of the heart and other structures in the mediastinum, and occupying the major part of the thorax, the pair of lungs act as the essential organ of respiration. Generally right lungs is divided into three lobes by one right horizontal and one right oblique fissure while the left lung is div ided into two lobes by left oblique fissure.
The variation in the appearance of the fissures can be attributed to their embryo logical origin. In prenatal life, individual bronchopulmonary segments are separated by fissures, which are gradually ob literated. Major (oblique) and minor (horizontal) fissures exist due to persistence of the fissures along the inter-lobar planes. In cases where

Material & method:-
During perfo rming routine dissection for undergraduate students, this rare case was noticed in the lungs of a 58 years old formalin fixed female cadaver in the Depart ment of Anatomy of Regional Institute of Medical Sciences, Imphal, India. The specimen was photographed and comparisons were made with normal ones.

Result:-
The right lung showed the presence of a single fissure. The oblique fissure was present and it divided the lung into two lobes namely upper and lower lobe. The oblique fissure started approximately at the level of the spinous process of T4 level of thoracic spine and it crossed the fifth intercostals space and roughly followed the contour of the sixth rib anteriorly. Depth of the fissure was about 1.5 cm pro ximally, 2 cm at the terminal part, 2.5 cm in the deepest part. No accessory fissure was there. Horizontal fissure that divides the right lung into additional middle lobe normally, was absent. The rest of the costal surface was smooth with impression of ribs visible. Structures in the hilu m were all normal in position as well as the imp ressions over the medial surface were all intact.
In case of the left lung, there was complete absence of the oblique fissure. Costal surface was convex and smooth in appearance. Structures in hilu m were normal with intact imp ressions along medial surface. No accessory lobe was visible and lingula was normal.

Discussion:-
After examination of 1200 pairs of lungs it was found that incomplete oblique fissure was present in 10.6% of left lung and oblique fissures were absent in 7.3% of the left-sided lung (Medlar E.M, 1947).
In a CT scan study, analysis of both lungs in 154 patients, including seven cadavers, it was concluded that the frequency of the incomplete inter-lobar fissure was high in right sided lungs which was 83.1%, when compared to the left lungs that was 50% (Otsuji. H et al., 1993).