Study on Anatomical Variations in Fissures of Lung by CT Scan

Introduction Refinements in the modern computed tomography (CT) imaging techniques have led to anatomical variations in the fissures of lung being diagnosed more frequently. So far, majority of the studies conducted are cadaveric. There is paucity of studies in this aspect based on chest CT images. Hence, we undertook this study to find the anatomical variations in the fissures. Prior detection of anatomical abnormalities is important to reduce postoperative complications in lung resection surgeries. Materials and Methods This was a cross-sectional study conducted over a period of 2 years. Data were collected from the patients who underwent CT scan thorax. Patients in whom normal anatomy of lung was distorted and cases where both lungs were not visualized completely were excluded from the study. All the CT images were reviewed by a single radiologist. The presence or absence of the normal and accessory pulmonary fissures, as well as the continuity of each fissure, was recorded by the radiologist. Data were compiled and analyzed. Results The study population consisted of 394 (70.4%) males and 166 (29.6%) females, totaling 560 cases. Fissural variations were detected in 22.9% (n = 128). Also, 17.5% (n = 98) fissural variations were seen in males and 5.4% (n = 30) fissural variations were seen in females. Further, 54.7% (n = 70) of variations were detected in the right lung and 45.3% (n = 58) in the left lung. The most common fissural variation noted was right incomplete oblique fissure with a frequency of 8.4% cases (n = 47). The most common accessory fissure detected was inferior accessory fissure. Total 22 cases were detected in both the lungs, 17 cases in male and 5 in female. Conclusion Anatomical variations in fissures were found to be more in the right lung than the left lung. Accessory fissures were detected in higher incidence on the right side.

A Study on Morphological Variations of Fissures and Lobes of Human Lungs with its Clinical Significance

Background: Fissures of lungs facilitate the movement of lobes which helps in expansion of lungs during breathing. The fissures may be complete, incomplete or absence. Sometime the accessory fissures may also present. Awareness of variations is essential during segmental resections as well as during radiological interpretation of lungs. Hence, the present study was aimed to study the morphological variations in fissures and lobes. Material and Methods: This study was consisted of sixty nine human lungs with irrespective of sex which were available in the department of anatomy of various medical colleges. All lung specimens were carefully observed and recorded for the presence of any variations in fissures and lobes. Results: The present study revealed that the absence of horizontal fissure was observed in 7.89%, while no specimen showed absence of oblique fissure on both sides. 35.48% of left lungs had incomplete oblique fissure compared to 28.95% of the right lungs. In addition, 22.58% of right lungs and 23.68% of left lungs showed presence of accessory fissure and lobes. From above, the incomplete and absent horizontal fissure was the most common abnormalities observed in this study. The accessory fissures were more common in lower lobe of right lung whereas in left lungs it was more common in upper lobe. Conclusion: The present study showed the wide range of variations in fissures and lobes of lungs. The knowledge of variations in morphology of lungs would be helpful for clinical diagnosis and pulmonary surgical procedures.

Morphological Variation of Fissure and Lobe of the Left Lung: A Case Report

The left lung usually has an oblique fissure that divides it into superior and inferior lobes. Some variants in the lobar fissure are well known, but the knowledge of certain uncommon variants will enhance our anatomical understanding and proper identification of the bronchopulmonary segments. Several imaging techniques have been used to describe anatomical variations of the lung, but studies that utilize dissections as tools for understanding lobar variations were limited. In this report, we described an incomplete horizontal fissure, bifurcated accessory fissure, incomplete superior and middle lobes, and fibrous condensation of the left lung pulmonary pleura observed during dissection. The knowledge of these anatomical variations will be useful in surgical segmental resection and lobectomy, and for accurate interpretations of medical diagnostic images.

Perioperative Identification of an Accessory Fissure of the Right Lung

Anatomical variations of lungs are common in clinical practice; however, they are sometimes overlooked in routine imaging. Surgical anatomy of the lung is complex and many variations are known to occur. A defective pulmonary development gives rise to variations in lobes and fissures. Morphological presentation is of clinical importance and profound knowledge of the organogenesis and functional anatomy is imperative for the interpretation and evaluation of lung pathophysiology and subsequent surgical intervention. However, appreciating them on radiographs and CT scans is difficult and they are therefore often either not identified or completely misinterpreted. As presented in this case report, an accessory fissure separating the superior segment of the right lower lobe from its native lobe was seen perioperatively and could only retrospectively be defined on X-rays and CT scan. It is imperative to keep in mind that accessory fissures can be missed on imaging studies and thus can make the surgical procedure more challenging.

A cadaveric study of anatomical variations of fissures and lobes of lung

Background and aim: The anatomical variations of fissures and lobes of lungs have been described by many research workers on CT scans, whereas, there were fewer studies done on gross anatomical specimens. Materials and methods: In the present study, 30 embalmed cadavers have been dissected and lungs were examined for fissures and lobes. Results: Nine out of 30 left lungs showed incomplete oblique fissures. Eight out of 30 right lungs showed incomplete transverse fissure but oblique fissure was complete, and in two right lungs, incomplete oblique and transverse fissures were found. In one cadaver one accessory lobe and one accessory fissure was present, on right side. Comparative analysis of present work with data in literature suggest that different studies performed on radiological images reported greater prevalence of incomplete or absence of pulmonary fissures as compared to present cadaveric study. Therefore our findings with regard to fissures and lobes are different from many studies but are approximately similar to two. Conclusion: Variation of lung anatomy is important for cardio-thoracic surgeons, radiologists for interpreting x-rays, CT scans and MRI and also it is of academic interest to all medical persons.

Non-Azygos Accessory Fissure in Right Upper Lobe Associated with Superior and Inferior Accessory Fissures in Right Lower Lobe

Accessory fissures in the lungs are common congenital variations, usually detected as incidental findings in radiographs or CT scan. Accessory fissures can act as an anatomic barrier to the spread of inflammatory or neoplastic disease, as well as due to the variant anatomy, mimic lesions. It is important to recognize the presence of accessory fissures, as they affect surgical planning of pulmonary lobectomy and segmentectomy. Accessory fissure in the right upper lobe other than due to the anomalous course of azygos vein is very rare. We report a case of non-azygos accessory fissure, between the apical and the anterior segments of right upper lobe, along with superior and inferior accessory fissures in the right lower lobe.