Clinical significance of the diverse interlobar veins hidden in the upper oblique fissure.

Background: The interlobar veins hidden in the upper oblique fissure (UOF) of the right lung are usually mismanaged cursorily according to the target lobe, which results in accidental injury of the interlobar veins and complications. The detailed classification of interlobar veins based on surgical anatomical analysis is of great clinical significance. Methods: Three-dimensional computed tomography bronchography and angiography (3D-CTBA) reconstructed images of 398 patients from January 2019 to June 2020 were retrospectively analyzed. The interlobar veins in the UOF were observed and classified according to their morphology and distribution. The classification model was further validated in 153 patients who underwent surgery involving dissection of the UOF, and related surgical results were analyzed. Results: The distribution of interlobar veins was diverse, and the general morphology could be divided into 2 main categories and 30 subtypes in the 3D-CTBA images of the 398 patients. Analysis of the 153 patients' surgical data showed that 60 patients suffered from interlobar vein injury. Interlobar veins hidden in an incomplete UOF were the most susceptible to accidental damage (χ2=12.856, P=0.020). A receiver operating characteristic (ROC) curve analysis showed that an interlobar vein diameter larger than 2.4 mm for the oblique fissure interlobar vein type or less than 2 mm for the mediastinal interlobar vein type was associated with a higher risk of injuries (P<0.001). Conclusions: The diversity of interlobar veins and the completeness of the UOF were noteworthy risk factors in surgery involving dissection of the UOF.

Are textbook lungs really normal? A cadaveric study on the anatomical and clinical importance of variations in the major lung fissures, and the incomplete right horizontal fissure.

INTRODUCTION: The lungs have three main fissures: the right oblique fissure (ROF), right horizontal fissure (RHF), and left oblique fissure (LOF). These can be complete, incomplete or absent; quantifying the degree of completeness of these fissures is novel. Standard textbooks often refer to the fissures as complete, but awareness of variation is essential in thoracic surgery. MATERIALS AND METHODS: Fissures in 81 pairs of cadaveric lungs were classified. Oblique fissures were measured from lung hila posteriorly to the lung hila anteriorly; and the RHF measured from the ROF to the anteromedial lung edge. The degree of completeness of fissures was expressed as a percentage of the total projected length were they to be complete. The frequency and location of accessory fissures was noted. RESULTS: LOF were complete in 66/81 (81.5%), incomplete in 13/81 (16.0%) and absent in 2/81 (2.47%); ROF were complete in 52/81 (64.2%), incomplete in 29/81 (35.8%) and never absent; RHF were more variable, complete in 18/81 (22.2%), incomplete in 54/81 (66.7%) and absent in 9/81 (11.1%). LOF and ROF were on average 97.1% and 91.6% complete, respectively, being deficient posteriorly at the lung hila. The RHF on average 69.4% complete, being deficient anteromedially. There were accessory fissures in 10 left and 19 right lungs. CONCLUSIONS: This study provides a projection of the anatomy thoracic surgeons may encounter at operation, in particular the variable RHF. This knowledge is essential for optimal outcomes in both benign and oncological procedures influenced by the fissures.

An Efficient Method for the Detection of Oblique Fissures from Computed Tomography images of Lungs.

Detection of a pulmonary fissure in lungs is difficult due to its anatomical changeability among humans and it is essential in the clinical environment for accurate localizing and treating the lung abnormalities on a lobe level in human lungs. In this work, an algorithmic approach is proposed to detect the lung oblique fissures from lung computed tomography (CT) images. In the preprocessing module of our approach, the lung structures are enhanced using morphological operation and lung images are de-noised using Wiener filter. In the second module, lung regions are segmented using techniques, namely, thresholding and background subtraction. In the third module of our algorithm, initially, fissure regions are segmented using the active contour model, then by applying the rule based approach on the fissure regions, the oblique fissures are segmented. The proposed algorithm has been tested on 50 images collected from Lung Image Database Consortium (LIDC) and 30 images obtained from Early Lung Cancer Action Program (ELCAP).

Linear shadows that connect oblique fissures and costal pleurae on the superior segments of lower lobes: evaluating the imaging findings on thin-slice lung CT.

OBJECTIVE: To retrospectively analyse the imaging findings of the linear shadows that connect the oblique fissures and the costal pleurae on the superior segments of the lower lobes on thin-slice lung CT. MATERIALS AND METHODS: Thin-slice CT scans of 221 cases of normal lungs and 86 abnormal lungs were collected. The parameters of the imaging observations included the existence of the superior segmental linear shadow, its morphology, length, and starting position, bird-beak sign, and adjacent structures on the pleural end. RESULTS: The linear shadows were more common on the left lower lobe (43.44%) than on the right side (19.46%). The pleural origins of the linear shadows were mainly located above the carina (69.78%); the adjacent structure on the left lung was the descending aorta (70.83%), and for the right lung, it was next to the thoracic vertebrae (60.47%). In the presence of pulmonary lobectomy or atelectasis, the linear shadows could be extended, which could pull the oblique fissures and costal pleurae to form the bird-beak sign. CONCLUSION: The linear shadows on the superior segments of the lower lobes are common structures fixing the oblique fissures. Recognition of the linear shadows can help radiologists distinguish normal structures from abnormal ones.

A case of anomalous horizontal fissure and hypoplastic middle lobe of the right lung / Un caso de fisura horizontal anómala y lóbulo medio hipoplásico del pulmón derecho

During dissection practice for medical students at Nagasaki University, a horizontal fissure and hypoplastic middle lobe were encountered in the right lung of an 81-year-old Japanese female. In a normal right lung, the horizontal fissure is situated anterior to the oblique fissure. On the contrary, in the present case, the horizontal fissure was situated posterior to the oblique fissure. We identified a small, additional lobe on the medial surface of this lung. It was situated in the medial part of the oblique fissure, and was determined to be a small hypoplastic middle lobe. As a result of the hypoplasia of the middle lobe, the original horizontal fissure may have disappeared from the anterior surface. The horizontal fissure, in this case, may be a compensatory additional fissure that developed within the inferior lobe. This horizontal fissure was incomplete, both in length and depth. The left lung was normal. This case might be very rare; however, it may aid in the understanding of normal lung development. Therefore, we report this case, including its bronchial branching and vascular distribution.

Durante la práctica de disección para estudiantes de medicina en la Universidad de Nagasaki, se encontró una fisura horizontal y un lóbulo medio hipoplásico en el pulmón derecho de una mujer japonesa de 81 años de edad. En un pulmón derecho normal, la fisura horizontal está situada anterior a la fisura oblicua. Por el contrario, en el presente caso, la fisura horizontal estaba situada posterior a la fisura oblicua. Se identificó un pequeño lóbulo adicional en la superficie medial de este pulmón. Estaba situado en la parte medial de la fisura oblicua, y se determinó que era un pequeño lóbulo medio hipoplásico. Como resultado de la hipoplasia del lóbulo medio, la fisura horizontal original puede haber desaparecido de la superficie anterior. La fisura horizontal, en este caso, puede ser una fisura adicional compensatoria que se desarrolla dentro del lóbulo inferior. Esta fisura horizontal era incompleta, tanto en longitud como en profundidad. El pulmón izquierdo era normal. Este caso podría ser muy raro; Sin embargo, puede ayudar en la comprensión del desarrollo pulmonar normal. Por lo tanto, informamos este variación, incluyendo su ramificación bronquial y la distribución vascular.

Evaluation of the oblique fissure on lateral chest radiographs in coal workers pneumoconiosis.

OBJECTIVE: The oblique fissure separates the upper lobe from the lower lobe in the left lung and the upper lobe from the lower and middle lobes in the right lung. The aim of the present study was to compare the projection of the oblique fissure observed on lateral chest radiographs of retired coal mine workers who had coal worker's pneumoconiosis (CWP) with that of healthy men. MATERIALS AND METHODS: The study included 120 men divided into three groups: retired coal miner patients diagnosed with CWP (group 1), men ≥38 years of age with no CWP (group 2, first control group), and men ≤37 years of age with no CWP (group 3, second control group). The projection of the oblique fissure observed on lateral chest radiographs (left side) were evaluated using geometric morphometrics. Geometric morphometric analysis of each sample was performed using 11 pre-specified landmarks designated on X-ray images, using tpsDig2 software. A text file containing the landmark coordinates of the 120 samples was created, and the data in the text file was statistically analyzed using Morpheus software. RESULTS: The projection of the oblique fissure differed significantly between the CWP patients and the control groups (p<0.05). CONCLUSION: We suggest that the difference in the projection of the oblique fissure between men with and without CWP was attributable to a protrusion in the fissure caused by nodules that developed in the lungs of coal miners after years of dust inhalation (Tab. 4, Fig. 4, Ref. 30).

Variations in the inter-lobar fissures of lungs obtained from cadavers of south Indian origin / Variaciones en las fisuras pulmonares interlobulares de cadáveres del sur de la India

The proposed aim of the study was to elucidate the variations of the lung fissures and to correlate their importance in clinics. The study was conducted on 48 lung specimens, 30 right and 18 left, obtained from the cadavers of South Indian origin. Among the right-sided lungs, 2 specimens showed absence of horizontal fissure, and the remaining 25 showed incomplete horizontal fissure. Oblique fissure was incomplete in 15 lungs and one lung showed absence of oblique fissure. An accessory fissure was observed in 4 lungs. Among the left sided lungs, the oblique fissure was incomplete in 7 lungs. The presence of an accessory fissure was found in 5 lungs. With the development of radiological and endoscopic techniques and the advancement of pulmonary surgery, the knowledge of morphological variations of lung fissures is of utmost importance to clinicians to correctly locate the bronchopulmonary segment during pulmonary lobectomy, and for radiologists to correctly interpret X-rays and CT scans.

El objetivo fue determinar las variaciones de las fisuras del pulmón y correlacionarlas con su importancia clínica. Se utilizaron 48 muestras de pulmón, 30 del lado derecho y 18 del izquierdo, obtenidos de cadáveres de origen del Sur de la India. Entre los pulmones, en el lado derecho, dos mostraron ausencia de la fisura horizontal, y 25 mostraron una fisura horizontal incompleta. La fisura oblicua fue incompleta en 15 pulmones y en 1 pulmón estuvo ausente. Se observó una fisura accesoria en 4 pulmones. Entre los pulmones del lado izquierdo, la fisura oblicua estuvo incompleta en 7 casos. La presencia de una fisura accesoria se observó en 5 casos. Con el desarrollo de técnicas radiológicas, endoscópicas y el avance de la cirugía pulmonar, el conocimiento de las variaciones morfológicas de las fisuras de pulmón es de importancia para los médicos, permitiendo localizar correctamente el segmento broncopulmonar durante la lobectomía, y para los radiólogos para interpretar correctamente las radiografías y las Tomografías Computarizadas.