Abstract
Background The aim of the present study was to determine the prevalence of anatomical transposition
of the remaining right middle lobe after right upper lobectomy and the effect of this
transposition on postoperative global pulmonary function.
Methods We correlated the postoperative pulmonary anatomical change with the functional change
in patients undergoing right upper lobectomy for lung cancer. To estimate the regional
pulmonary function, we measured the regional volume of the lung using normal lung
attenuation values (− 600 to − 910 Hounsfield units), known as the functional lung
volume, by computed tomography. The position of the middle lobe was objectively evaluated
using volume-rendering three-dimensional computed tomography lung models. Intraoperatively,
middle lobes were not fixed with the lower lobes.
Results Postoperatively, the middle lobe remained attached to the anterobasal segment in
24 patients, whereas it migrated cranially in the remaining 26 patients. The functional
volume of the middle lobe changed by various degrees postoperatively (range: 9 to
171% of preoperative values, mean: 96 ± 34%), and this change was significantly associated
with the global pulmonary function (R = 0.5, p = 0.01). However, there were no significant differences between patients with and
without middle lobe migration with respect to the postoperative functional volume
of the middle lobe, the postoperative functional volume of the total lung, and global
pulmonary function.
Conclusion Right middle lobe transposition after upper lobectomy is not associated with the
deterioration of pulmonary function, but unexpected deflation of the right middle
lobe is. Strategies for preventing middle lobe deflation should be explored in the
clinical setting.
Keywords
lobectomy - pulmonary function - lung cancer
