Effect of Lung Volume Reduction Surgery on Bony Thorax Configuration in Severe COPD: ResultsAll data are expressed as mean ± SD, except where otherwise noted. Statistical analysis was performed using two-tailed paired Student’s t test to compare preoperative with postoperative values. Repeated measures analysis of variance was used to compare preoperative measurements with those at 3 and 12 months after LVRS. Linear regression analyses with Pearson correlation were used to evaluate correlations between roentgen-ographic and physiologic measurements. Values of p < 0.05 were considered statistically significant. All statistical analyses were conducted using a commercially available computer software program (Sigmastat, version 1.0; Jandel Corp; San Rafael, CA).
Results
Patient Characteristics
Baseline characteristics of 25 patients in the study cohort are shown in Table 2. Patients were 58 ± 8 years old, and 14 were females. All patients were functionally limited, designated as New York Heart Association class III or IV. The majority were oxygen dependent, had a significant smoking history, had hyperinflation with severe airflow obstruction, and had abnormal gas exchange. All patients finished 8 weeks of outpatient pulmonary rehabilitation before LVRS. All preoperative baseline data were taken after completion of rehabilitation. canadian health mall

Physiologic Data
Results of lung function studies (spirometry, lung volumes, 6MWD) and diaphragm strength (Pdimax sniff) at baseline and 3 months after LVRS can be seen in Table 3. All patients had severe airflow obstruction, moderate to severe hyperinflation, and decreased exercise tolerance. At 3 months after LVRS, FEV1 improved to 0.87 ± 0.29 L (p < 0.001), total lung capacity (TLC) decreased to 6.6 ± 1.4 L (p < 0.001), and 6MWD increased to 330 ± 84 m (p < 0.001). There was also a significant improvement in mean Pdimax sniff (p < 0.0001).
Roentgenographic (Plain Film) Data
Seven of the 25 patients had plain CXRs done previously within a year of their baseline presurgical evaluation. Table 4 demonstrates the rib cage dimensions in these seven patients, measured using plain CXRs, done previously within a year before evaluation for LVRS (controls) and during preoperative assessment. There was no significant change at any thoracic level in AP or transverse rib cage dimensions when preoperative measurements were compared with control films; however, the sample size is relatively small to detect a significant difference.

Table 2—Baseline Characteristics in All 25 COPD Patients

Characteristics Mean ± SD (% predicted)
Age, yr 58 ± 8
Gender
Female, No. 14
Male, No. 11
NYHA functional class III and IV
Oxygen dependent, % 72
Steroid dependent, % 34
Smoking history, pack-yr 82±95
FEVj, L 0.63 ± 0.23 (26 ± 9)
TLC, L 7.8 ± 1.9(141 ± 22)
RV, L 4.9 ± 1.2 (244 ± 55)
6MWD, m 253 ± 114
Pao2/Flo2, mm Hg 314 ± 49
Paco2, mm Hg 45 ± 7.1

Table 3—Physiologic Data Before and 3 Months After Lung Volume Reduction Surgery

Data Baseline Post-LVRS Value
FEVj, L 0.63 ± 0.23 (26 ± 9) 0.87 ± 0.29 (33 ± 7) 0.001
TLC, L 7.8 ± 1.9(141 ± 22) 6.6 ± 1.36(121 ± 25) 0.001
6MWD, m 253 ± 114 330 ± 84 0.001
Pdimax sniff, cm H2O 41 ± 25 65 ± 14 0.0001

Table 4—Control Subjects’ Rib Cage Dimensions on Prior Examination and Immediately Before LVRS (Using Plain CXR; N = 7)

ExaminationTime AP Diameter, cm Transverse Diameter, cm
M T7 T11 M T7 T11
Baseline 21.9 ± 2.0 23.6 ± 1.7 24.2 ± 2.3 22.9 ± 2.5 26.0 ± 1.5 28.5 ± 2.2
Preoperative 21.2 ± 2.8 24.3 ± 2.0 24.9 ± 2.8 22.5 ± 1.6 26.1 ± 1.8 28.6 ± 2.1
p value 0.3 0.08 0.09 0.4 0.4 0.3