Abstract
After right upper (RU) lobectomy, a deformity of the orifice of the right middle lobe bronchus (RMLB) may be observed in some cases. In this study, we examined the relationship between the postoperative deformity of the orifice of the RMLB (ORMLB) and the pre-and post-operative right lung lobar volume ratio. Before and after RU lobectomy, the lobar volume ratio was calculated using computed tomography and the ORMLB was measured using bronchofiberscopy (n=19) . A preoperative ratio of the volume of the right upper lobe (RUL) to the volume of the right lung was not correlated with the postoperative deformity of the ORMLB. When a postoperative ratio of the volume of the right middle lobe (RML) to the volume of the right middle and lower lobes (RMLL) was less than 30%, postoperative deformity of the ORMLB was observed in a case who had preoperative semicircular ORMLB, but not in a case who had a round-shaped ORMLB preoperatively. To study the postoperative change in the RML to RMLL ratio, the preoperative RML to RMLL volume ratio was divided by the postoperative volume ratio. The ORMLB was deformed when the ratio was less than 60%, however, there was no deformity if the ratio was greater than 60%, regardless of the preoperative shape of the ORMLB. In conclusion, the preoperative volume ratio of the RUL to the right lung is not useful to predict the postoperative deformity of the ORMLB. Deformation of the ORMLB is not observed when the preoperative ratio of the volume of the RML to the volume of the RMLL is preserved after surgery.
