Postsurgical change in the tracheal bifurcation angle after upper lobectomy: radiographic evaluation.
ABSTRACT The purpose of this study was to evaluate postsurgical changes in the tracheal bifurcation angle on chest radiographs after upper lobectomy and to determine whether bronchial repositioning after upper lobectomy mimics that in upper lobe collapse.
The authors selected 81 patients who had undergone upper lobectomy with complete mediastinal and subcarinal lymph node dissection and in whom chest radiographs had been obtained before operation and at four postoperative intervals. The interbronchial angle and the subcarinal angle were measured on the preoperative and postoperative radiographs and compared statistically.
The average interbronchial angle and subcarinal angle during any postoperative period were significantly smaller than those before lobectomy (P < .001). These average angles decreased gradually during the postoperative periods.
The tracheal bifurcation angle was decreased on follow-up chest radiographs in most patients who underwent upper lobectomy with mediastinal lymph node dissection. This finding may be useful for establishing a history of this surgical procedure on the basis of chest radiographs.
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ABSTRACT: The aim of this study was to investigate the effect of body habitus, dimensions of the thoracic cavity, location of the carina within the mediastinum, and left atrial size on tracheal carinal angle using CT scan. The study population was drawn from the patients referred to CT scan for various indications. A total of 120 patients (65 men and 55 women; age range 17-85 years; mean age 56 years) who denied a history of prior thoracic surgery, and in whom CT scan excluded pulmonary fibrosis, moderate or severe emphysema, atelectasis, intrathoracic mass or adenopathy, pericardial or pleural effusion were prospectively enrolled. The interbronchial (IBA) and subcarinal (SCA) angles were measured on coronal reformatted images. The presternal and retrovertebral fat thickness, the anteroposterior and transverse diameters of the thorax, the distances from carina to the sternum and to the vertebral column were obtained at the level of carina. Three orthogonal dimensions and the volume of the left atrium were also assessed. The mean interbronchial angle was 77 degrees +/-13 degrees (range 49-109 degrees ) and subcarinal angle was 73 degrees +/-16 degrees (range 34-107 degrees ). IBA positively correlated with the female gender (r=0.25, p=0.007), body mass index (r=0.28, p=0.002), presternal (r=0.40, p=0.001) and retrovertebral fat thickness (r=0.31, p=0.001). The interbronchial angle was significantly greater in obese patients compared with lean patients (p=0.02). Both IBA and SCA were positively correlated with the left atrial volume (r=0.40, p=0.001 and r=0.34, p=0.001, respectively), and its transverse and craniocaudal dimensions. The carina-vertebral column distance inversely correlated with IBA (r=-0.42, p=0.001) and SCA (r=-0.41, p=0.001). The size of the thoracic cavity did not show significant relation to tracheal bifurcation angle. Tracheal bifurcation angle ranges widely in normal subjects, and absolute measurements of the carinal angle is of little diagnostic value. In addition to left atrial enlargement, female gender, obesity and close situs of carina relative to vertebral column are associated with greater tracheal bifurcation angle.British Journal of Radiology 10/2005; 78(933):787-90. · 1.22 Impact Factor