Predictors of improvement in FEV1 (forced expiratory volume in 1s) after lung volume reduction surgery

We evaluated various preoperative and operative factors to identify the predictors of improvement in forced expiratory volume in 1s (FEV1) after lung volume reduction surgery (LVRS). Fifty-eight emphysema patients received bilateral LVRS either via a sternotomy (n = 53) or by thoracoscopy (n = 5). The patients were divided into the following two groups: group I (n = 17), patients whose FEV1 improved by less than 20%; group II (n = 41), patients whose FEV1 improved by more than or equal to 20%. The preoperative factors (age, degree of dyspnea, oxygen use, steroid use, pulmonary function test, arterial blood gas, pulmonary hemodynamics, 6-min walking distance) and operative factors (removed lung weight, number of staplers) were both similar between the two groups. Upper lobe type emphysema was more frequently seen in group II and the average improvement in FEV1 was significantly better in the patients with upper lobe type emphysema (62.8% +/- 8.5%) than lower lobe type (36.9% +/- 7.6%) and mixed type (35.5% +/- 6.5%), P < 0.01. Severe pleural adhesion was more frequently found in group I and the average improvement in FEV1 was also significantly lower in patients with severe pleural adhesion (19.8% +/- 6.4%) than mild-to-moderate adhesion (46.8% +/- 5.3%) and no-to-minimal adhesion (62.3% +/- 10.4%), P < 0.01. These results lead us to conclude that upper lobe type emphysema may thus be a predictor of better FEV1 improvement while severe pleural adhesion is considered to be a predictor of a poorer FEV1 improvement after bilateral LVRS.