Is long-term functional outcome after lung volume reduction surgery predictable?

Objective: The aim of this retrospective study was to analyze which preoper ative parameters might predict a persistent improvement in forced expirator y volume in 1 s (FeV1) 1 year after surgery. Methods: Seventy consecutive l ung volume reduction surgery (LVRS) patients (age, 56.5 +/- 1.2 years) with a follow-up period of at least 1 year were analyzed (from September 1994 t o September 1997). The patients were described by lung function tests, bloo d gas analysis, ventilatory mechanics (intrinsic positive endexpiratory pre ssure (PEEP)) and morphometric data (degree of heterogeneity, DHG; degree o f hyperinflation, DHI; severity of parenchymal destruction, SPD) preoperati vely. Based on the postoperative course of FeV1 (percentual increase compar ed with preoperative values, % increase), patients were divided into four g roups: group A, (n = 21) no improvement (FeV1 less than or equal to 20% inc rease); group B, (n = 10) FeV1 greater than or equal to 20% increase, which declined to preoperative values after 1 year; group C, (n = 18) FeV1, 20-4 0% increase, sustaining at 1 year; group D, (n = 21) FeV1 greater than or e qual to 40% increase, sustaining at 1 year. The statistics comprised of ana lysis of variance (ANOVA) and chi-square testing, with values presented as means +/- SEM. Results: No differences were found for lung function paramet ers (FeV1: 27.7 +/- 2.7, 26.0 +/- 2.5, 23.9 +/- 2.2 and 23.9 +/- 1.9% predi cted, in groups A, B, C and D, respectively). Arterial blood gas levels pre operatively revealed significant differences between the groups; the arteri al pO(2) was 66.2 +/- 1.2 mmHg in groups A + B compared with 61.8 +/- 1.5 m mHg in groups C + D (P = 0.030). The arterial pCO(2) was 39.2 +/- 1.1 mmHg in groups A + B compared with 43.3 +/- 1.5 mmHg in groups C + D (P = 0.038) . The morphometric data had a strong trend towards higher heterogeneity in groups C and D. Marked DHI was found in 59 and 81% of patients in groups A + B versus C + D, respectively (P = 0.121). Marked DHG was present in 22 an d 54% of patients in groups A + B versus C + D, respectively (P = 0.010). C onclusion: Preoperative arterial pO(2) and pCO(2), and the DHG are predicto rs for long-term benefit after LVRS with regard to the FeV1, 1 year postope ratively. (C) 2000 Elsevier Science B.V. All rights reserved.