Lung volume reduction surgery: Effects of distribution of emphysema and site of resection

Purpose: Emphysema in smokers often has an upper lobe predominance, though lower lobe predominance or diffuse disease may occur instead. We evaluated whether outcomes were effected by site of disease or resection. Methods: We retrospectively analyzed data from the first 110 consecutive pts who had bilateral median sternotomy lung volume reduction surgery (LVRS). Upper lobe (ULE) vs lower lobe (LLE) vs diffuse emphysema was defined by the relative decreased distribution of perfusion seen on nuclear medicine scans (Q-scans) reviewed by 3 radiologists & 2 pulmonologists. LVRS involved resection of the most predominant areas of emphysema. The upper lobes were predominantly reduced (ULS) in the ULE group, in 1 pt of the LLE group, & in 9/10 of the diffuse group. All others had predominantly lower lobe reductions (LLS). PFT, ABG, & 6-min. walk distance (6MWD) data were evaluated before (after an exercise rehab, program) & appro. 6 mo. after surgery. Outcome comparisons were made within groups (paired t-tests) & between groups (unpaired t-tests) based on disease distribution (ULE vs LLE vs diffuse) or resection site (ULS vs LLS). 6 pts with missing Q-scans were excluded from analysis. Results: Preop: all groups had similar data. Postoperative change (mean±SD) in parameters based on predominant emphysema pattern n avail. for test n=68 n=15 n=10 Parameter ULE LLE Diffuse FEV1ΔL .35±.28* .16±.18 .26±.12 RVΔL -1.8±1.2** -1.8±1.3 -.93±1.2 PaCO2Δmm Hg -5±6*** -1±5 -3±5 PaO2Δmm Hg 11.±11 6±8 5±6 6MWDΔft 176±270 128±309^† 164±184 Alive:Dead¥ 72:4 17:1 10:0 ¥ =hospital deaths; *n=64; ^†n=16; Significant (P<.05) findings within groups=nonshaded parameters; significant findings between groups are: *P=.017 for ULE vs LLE; **P=.035 for ULE vs diffuse; *** P=.047 for ULE vs LLE. Based on predominant site of resection (not based on emphysema pattern), 86 pts were grouped as ULS & 18 as LLS. All parameters improved within each group except for the PaCO2 & the 6MWD in the LLS group. Improvements were similar between groups except for a greater decrease (P<.05) in PaCO2 for the ULS group. Conclusions: Whether classified by distribution of emphysema or by predominant site of reduction, improvements were greatest in both the ULE & ULS groups, though the other groups had significant improvements as well. Clinical Implications: Outcome after LVRS may be effected by site of resection or by distribution of disease.