Apical perfusion fraction as a predictor of short-term functional outcome following bilateral lung volume reduction surgery.

Abstract

STUDY OBJECTIVES: To examine whether relative hypoperfusion to the apical one third of the lungs as determined by lung scintigraphy predicts a favorable functional outcome following bilateral lung volume reduction surgery (LVRS). METHODS: We performed a retrospective analysis of 128 patients who underwent bilateral LVRS. An apical perfusion fraction (AP%), defined as the percentage of total lung perfusion to the apical one third of both lungs, was derived for each patient by quantitative scintigraphy technique. Pulmonary function testing and 6-min walk test (6MWT) data were obtained preoperatively and 3 to 6 months postoperatively. RESULTS: The mean (+/- SD) improvement in FEV(1) was 309 +/- 240 mL, 209 +/- 293 mL, and 116 +/- 224 mL for patients with an AP% of <or= 10%, 11 to 20%, and > 20%, respectively (p = 0.01, analysis of variance [ANOVA]). The likelihood of experiencing an increase in FEV(1) >or= 200 mL was 68% for those with an AP% <or= 10% but only 31% for those with an AP% > 20%. Preoperative and postoperative 6MWT data were available for 109 of 128 patients. Improvement was 250 +/- 252 feet, 205 +/- 299 feet, and 77 +/- 200 feet for patients with AP% <or= 10%, 11 to 20%, and > 20%, respectively (p = 0.04, ANOVA). While 50% of those with an AP% <or= 10% improved their 6MWT by >or= 180 feet, only 21% of those with an AP% > 20% did so. CONCLUSION: This retrospective analysis suggests that quantification of apical perfusion by nuclear scintigraphy assists in predicting the likelihood of short-term functional improvement after LVRS.