Endoscopical and Pathological Study on Deformation of the Residual Bronchus after Upper Lobectomy of the Left Lung

Deformation of the residual bronchus after lobectomy is observed most predominantly in case of left upper lobectomy. To know the actual frequency and degree of the deformation of the residual bronchus after left upper lobectomy, 19 patients were observed bronchofiberscopically three weeks to 21 year after left upper lobectomy. The cause of the deformation of the residual bronchus was investigated pathologically, comparing with endoscopical findings, in one patient, whose residual left lung was removed accidentally five years after the left upper lobectomy. The endoscopically observed deformations of the residual bronchus after left upper lobectomy were (1) bend of the left main bronchus to upward, (2) clockwise torsion of the left main bronchus around the longitudinal axis at an angle of 60-90°, (3) protrusions of the bronchial wall, and (4) bronchial stenosis due to the protrusions. The deformations of the left main bronchus were observed in all of the 19 patients. Following the torsion of the main bronchus, forward movement of the stump of the upper lobe bronchus was observed also in all patients. Protrusion of the bronchial wall was seen in 18 out of 19 patients. Site of the development of the protrusion was in the orifice of the left lower lobe bronchus in 16 patients, in the distal portion of the main bronchus in 1, and in the basal segmental bronchus in 1. Bronchial stenosis, produced by the protrusion, was seen most frequently in the orifice of the basal segmental bronchus, in 15 out of 18 patients with development of the protrusion ; in the orifice of the lower lobe bronchus in 2, in whom the belonging segmental bronchi were not stenosed ; and in the main bronchus in 1, in whom the stenosis was localized only in the site of protrusion. The pathological investigation of the resected lung revealed that the protrusion of the bronchial wall, which was proved bronchofiberscopically before operation, was composed of folded bronchial cartilages covered with the mucous epithelium. This fact is suggesting that the protrusion of the residual bronchus after the left upper lobectomy is developed by folding of the bronchial wall due to a sharp bend of the bronchus, caused by movement and reexpansion of the residual lung. By analysis of the relation between the closing method of the bronchial stump of the left upper lobe and deformation, it became clear that development of protrusion was less in case that was suture line was crossing the longitudinal axis of the residual bronchus, than in case that was parallel to the axis. Therefore, it is concluded that development of the protrusion of the residual bronchial wall after the left upper lobectomy can be prevented by the method of closure of the bronchial stump.